Structure Data of Free Polyatomic Molecules 3030294293, 9783030294298

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Natalja Vogt · Jürgen Vogt

Structure Data of Free Polyatomic Molecules

Structure Data of Free Polyatomic Molecules

Natalja Vogt • Jürgen Vogt

Structure Data of Free Polyatomic Molecules

123

Natalja Vogt Section of Chemical Information Systems Institute of Theoretical Chemistry University of Ulm Ulm, Germany

Jürgen Vogt Section of Chemical Information Systems Institute of Theoretical Chemistry University of Ulm Ulm, Germany

Chemistry Department Lomonosov Moscow State University Moscow, Russia

ISBN 978-3-030-29429-8 ISBN 978-3-030-29430-4 https://doi.org/10.1007/978-3-030-29430-4

(eBook)

© Springer Nature Switzerland AG 2019 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Dedicated to Dr. Barbara Mez-Starck in occasion of the 20th anniversary year of her foundation supporting spectra and structure research

Foreword

The structure of a molecule has a significant influence on its properties. In other words, molecular geometry is required to explain molecular behavior. This is particularly important in biochemistry. There is indeed considerable evidence that odors, enzymatic activity, etc. are all subject to stereochemical control. Molecule (from new latin molecula = small mass) is the smallest unit, consisting of groups of atoms, into which a substance can be divided without a change in its chemical structure (Oxford dictionary). The concept of molecular structure was mainly developed during the nineteenth century. It was postulated that a molecule is made up of atoms (Proust 1806) and that the distances between the atoms are constant. The main question was what force keeps the atoms together. An obvious answer was the electrostatic attraction (Davy 1806) but it was not completely convincing, in particular for organic molecules (Dumas 1834), and it was necessary to wait for the development of quantum mechanics in the first half of the twentieth century to find a satisfactory explanation. However, some reputed scientists contested the existence of molecules as there was no direct experimental proof, at least, until the work of Jean Perrin in 1908 on the Brownian motion. The first measurement of interatomic distances was made by the diffraction of X-rays (Röntgen 1895 [1]) by crystals (M. von Laue 1912 [2]). In 1913, the structure of NaCl was determined by W. H. Bragg and W. L. Bragg [3]. Now, X-ray crystallography is used to study pharmaceutical drugs, proteins, etc. There are, however, several limitations. As X-rays interact with electrons, the method is not sensitive for light atoms such as hydrogen. Furthermore, it does not determine the distance between the nuclei of the atoms but between the center of mass of the electrons (for polar bonds between light atoms, the difference may be significant). Although, X-ray diffraction is not well suited to the study of isolated molecules, Debye et al. could determine in 1929 the structure of CCl4 in gas-phase [4]. But a great advance was made by H. Mark and R. Wierl by performing in 1930 the first gas-phase electron diffraction experiment [5]. With this method, the structure of many molecules was determined in a short time which enabled Pauling to refine the concept of chemical bond. Nowadays gas-phase electron diffraction is one of the best methods to determine the structure of a molecule in gas-phase. Molecular spectroscopy and, in particular, microwave spectroscopy which appeared after the Second World War, is also a widely used method to determine the structure of gas-phase molecules. For small molecules, its accuracy is wonderful. For instance, the bond length of CO is known to be re = 1.128230(1) Å (Authier 1993 [6]). For diatomic molecules and most triatomic molecules, the equilibrium structures are nowadays extremely accurate. However, for larger molecules, the structure is still often empirical, i.e. it is difficult to estimate the accuracy and it was even very bad in some cases. Nevertheless, if a cubic force field is available (in most cases, from an ab initio computation), the experimental rotational constants can be corrected, and then an accurate equilibrium structure can be derived for medium-sized molecules. A typical example in this book is fructose with 24 atoms (N. Vogt et al. 2016 [7]).

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viii

Foreword

In 1927 Heitler and London [8] were able to achieve the first theoretical calculation of the structure of H2 by quantum chemistry. The apparition of the computer and its recent considerable increase in power as well as the development of sophisticated computational methods (as the coupled cluster method) now permit to obtain accurate estimates of equilibrium structures often in a faster way than with experimental methods. However, quantum chemists need accurate structures to check their calculations. For instance, Ruden et al. computed the structure of CO in 2004 [9] and, using higher-order corrections to the usual coupled cluster method, they obtained 1.1284 Å in fair agreement with the experimental value. It is worth noting that the authors used an old experimental value that was in perfect agreement with their result. It demonstrates that the progress of ab initio methods remains dependent of experimental results. Another reason why it is important to have readily available tables of accurate molecular structures is the parameterization of molecular mechanics programs (and combined quantum/classical methods). These programs, used to compute the properties of very large molecules are parameterized against molecules, whose structure is assumed to be accurate. A third reason is that understanding molecular geometry also helps scientists to understand the shapes of more complex molecules such as proteins and DNA. As already noted, the knowledge about the shapes of the molecules is important to understand their properties. Lille, France

Jean Demaison University of Lille

References 1. Röntgen WC (1895) Ueber eine neue Art von Strahlen. Vorläufige Mittheilung. In: Sitzungsberichte der Würzburger Physikalisch-medizinischen Gesellschaft (in German), Würzburg 137:132–141. 2. Friedrich W, Knipping P, von Laue M (1912) Interferenzerscheinungen bei Röntgenstrahlen (in German) (Interference phenomena with X rays). In:Sitzungsberichte der Mathematisch-physikalischen Classe der KB Akademie der Wissenschaften zu München (in German), München 22:303. 3. Bragg WH, Bragg WL (1913) The reflection of X-rays by crystals. Proceedings of the Royal Society of London Series A, Containing Papers of a Mathematical and Physical Character 88:428–438. 4. Debye P, Bewilogua P, Ehrhardt F (1929) Zerstreuung von Röntgenstrahlen an einzelnen Molekülen (vorläufige Mitteilung) (in German) (Dispersion of x-rays by single molecules). Phys Z 30:84–87. 5. Mark H, Wierl R (1930) The determination of molecular structure by the diffraction of electrons by a stream of vapor (in German). Z Elektrochem 36:675–676. 6. Authier N, Bagland N, Le Floch A (1993) The 1992 evaluation of mass-independent Dunham parameters for the ground state of CO. J Mol Spectrosc 160:590–592. 7. Vogt N, Demaison J, Cocinero EJ, Ecija P, Lesarri A, Rudolph HD, Vogt J (2016) The equilibrium molecular structures of 2-deoxyribose and fructose by the semiexperimental mixed estimation method and coupled-cluster computations. Phys Chem Chem Phys 18 (23):15555–15563. 8. Heitler W, London F (1927) Wechselwirkung neutraler Atome und homöopolare Bindung nach der Quantenmechanik (in German). Z Physik 44 (6-7):455–472. 9. Ruden TA, Helgaker T, Jørgensen P, Olsen J (2004) Coupled-cluster connected quadruples and quintuples corrections to the harmonic vibrational frequencies and equilibrium bond distances of HF, N2, F2, and CO. J Chem Phys 121 (12):5874–5884.

Acknowledgments

First of all, our sincere thanks are due to Prof. Jean Demaison for his cooperation, to Prof. Dr. Marwan Dakkouri for his very helpful suggestions, to Prof. Eugene Popov and Mr. Anatoly A. Batiukov for their cooperation in the development of the software for the visualization of molecular models. We are very grateful to the staff of the Springer Nature editorial office: senior editors Dr. habil. Claus E. Ascheron and Lydia Müller as well as editor Dr. Zachary Evenson for their thoughtful guidance and senior editorial assistant Mrs. Elke Sauer for her initiative and permanent support of this book project, as well as to Mr. Boopalan Renu from the book production service for his efforts in the preparation of this book. We also express our sincere thanks to our former coauthors of the preceding Landolt-Börnstein volumes “Structure Data of Free Polyatomic Molecules” (II/25, 28 and 30): Prof. Kozo Kuchitsu, Prof. Mitsutoshi Tanimoto and Prof. Eizi Hirota, for the establishment of the series of handbooks for structural chemistry. Moreover, we gratefully acknowledge prompt and non-bureaucratic copypright permission grants (for reuse of the tables) from Springer Nature Publishing, the American Institute of Physics, de Gruyter Publishing Berlin, the Institute of Physics, John Wiley & Sons and Wiley-VCH and last but not least to Prof. Oskar Koifman from ISUCT Publishers.

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Contents

1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 General Remarks . . . . . . . . . . . . . . . . . . . . 1.2 Short Description of Experimental Methods . 1.3 Significance of Geometric Parameters . . . . . 1.4 Uncertainties . . . . . . . . . . . . . . . . . . . . . . . 1.5 Presentation of Data . . . . . . . . . . . . . . . . . .

. . . . . .

1 1 1 10 14 15

2

Inorganic Molecules without Carbon Atoms . . . . . . . . . . . . . . . . . . . . . . . . .

33

3

Molecules Containing One Carbon Atom . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

4

Molecules with Two Carbon Atoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

5

Molecules with Three Carbon Atoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309

6

Molecules with Four Carbon Atoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399

7

Molecules with Five Carbon Atoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507

8

Molecules with Six Carbon Atoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585

9

Molecules with Seven to Nine Carbon Atoms . . . . . . . . . . . . . . . . . . . . . . . . . 671

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10 Molecules with Ten or More Carbon Atoms . . . . . . . . . . . . . . . . . . . . . . . . . 767 Compound Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 903

xi

Chapter 1. Introduction 1.1 General Remarks. This book presents structure data of free polyatomic molecules including free radicals and molecular ions determined by experimental methods in the gas phase and published in the literature between 2009 and 2017 (in total 972 molecules). Therefore, it can be used as an update to ten Landolt-Börnstein volumes “Structure Data of Free Polyatomic Molecules” (II/25A-D, II/28A-D, II/30A,B) [1-10] covering the data published between 1960 and 2008. For the data published before 1960, see Refs. [11,12]. The presented molecular structures have been determined by an analysis of gas-phase electron diffraction intensities and/or rotational (sometimes also vibrational) constants derived from microwave (MW), infrared (IR), Raman (Ra) and ultraviolet (UV) high-resolution spectra. The structure data are excerpted from original papers and systematized after critical expertise. In general, they are limited to molecules in the electronic ground state. Only a few exceptions are made in order to demonstrate the recent success of time-resolved electron diffraction (TRED) in the studies of electronically excited molecules. In many cases, only one structure type is selected from the given paper. The main criterion for the structure type preference is minimal structure deformation due to vibrational effects, i.e. the accurate equilibrium structures are favored. In some cases, the structures of different types are given together in order to demonstrate the magnitudes of vibrational or other effects. Nevertheless, the conventional (effective) structures are also widely presented in this book. They are of particular interest as being pure experimental. 1.2 Short Description of Experimental Methods High-resolution spectroscopy. Molecular spectroscopy ranges in the electromagnetic spectrum between the radiofrequency region and the soft X-ray region. The observed spectra are results of rotational transitions in the long wavelength region, of vibrational transitions in the infrared region and of electronic transitions in the visible and ultraviolet region. At high resolution, rotational fine structure of vibrational and electronic transitions can be also detected. Rotational analysis provides rotational constants and related parameters, which are used for the determination of accurate structure of free molecules. In recent years, a rapidly increasing number of weakly bound molecular complexes were investigated by MW and IR spectroscopy.

In the long-wavelength regions (microwave, millimeter-wave, submillimeter-wave and THz) the resolution is inherently high so that the rotational constants are readily determined with very high precision. Because of the huge progress in electronics within the last two decades the electronically accessible frequency range could be extended in the spectral applications to the THz region [13,14]. Nowadays Fourier transform (FT) techniques are used in most of the MW spectroscopic laboratories. Based on Balle’s and © Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_1

1

2

1 Introduction

Flygare’s pioneering work in 1981 several Fabry-Perot cavity Fourier transform microwave (FTMW) spectrometers were constructed in the meantime, most of them were applied to molecular beams in supersonic expansion in order to improve the spectral resolution and sensitivity [15]. For more than a decade chirped-pulse Fourier transform spectrometers have been also used [16]. Because they enable the collection of spectra with more than 10 GHz bandwidth in a single shot, the broadband microwave spectra can be recorded several orders of magnitude faster than it was possible with the previous techniques. Instead of spectroscopic investigations in the frequency domain, rotational spectra can also be taken in the ordinary optical manner in the far infrared region from 10 cm-1 (which corresponds to 0.3 THz) by high-resolution Fourier transform infrared (FTIR) spectroscopy, which uses the principle of the Michelson interferometer for a broad coverage of the electromagnetic spectrum [17]. The achieved resolution is often better than 0.001 cm-1. Because the brightness of synchrotron radiation is in the IR region some orders of magnitude higher than that of globar sources, several far infrared spectra are studied by synchrotron-radiation based Fourier transform spectroscopy. Rotationally resolved vibrational spectra can be obtained by both FTIR spectroscopy and tunable laser spectroscopy [17,18]. Because diode lasers are available from the mid infrared to the visible region, tunable diode spectrometers have become more common. However, the rotation-vibrational bands can only be observed for infrared-active vibrations; in these transitions the dipole moment of the molecule must change upon vibration. Rotational and rotationally resolved vibrational spectra can also be investigated by the Raman scattering of light [19]. In recent years, new schemes have been introduced in Raman studies by taking advantages both of Fourier transform spectrometers and of lasers. Unfortunately, these experiments are still limited to a small number of skilled laboratories. The Raman studies are especially useful for infraredinactive transitions. As a special application, the time-resolved rotational Raman four-wave mixing is used as a background-free rotational coherence technique with femtosecond pulses of a typical spectral bandwidth up to 120 cm-1; in this way, the range of the rotational Raman transitions is covered without exciting low-lying vibrational Raman bands [20]. Because the electronic energies are much higher than the rotational and vibrational energies, the electronic transitions occur in the short-wavelength region, namely in the visible and ultraviolet part of the electromagnetic spectrum. Only for a few compounds rotationally resolved electronic spectra have been recorded by laser spectroscopic techniques [21,22]. Both IR and Raman spectroscopic methods have an advantage over MW spectroscopy because a much larger number of spectroscopic transitions can be conveniently measured, often at higher values of the rotational quantum numbers. In many studies, the infrared and microwave data are combined in order to determine a full set of rotational constants. The theoretical fundamentals of the rotational [23], the rotation-vibrational [24], and the rotationvibration-electronic spectra [25] are reviewed elsewhere.

1.2 Short Description of Experimental Methods

3

The ground-state rotational constants are frequently reported with uncertainties of ±1×10–7 cm–1 (3 kHz) and ±1×10–5 cm–1 (0.3 MHz) in infrared and Raman investigations, respectively. In band spectra, two sets of rotational constants are obtained, those of the upper and lower states involved in the transition, and a statistical treatment allows the differences between the constants to be determined to precisions approaching or equal to microwave uncertainties (1 kHz or less). Thus, the equilibrium rotational constants of polar molecules can be quite precisely calculated by using ground-state rotational constants B0 and rotation-vibration interaction constants α determined from microwave and infrared spectra, respectively. Despite the recent instrumental improvements, the resolution available from both infrared and Raman studies is still much lower than that from microwave spectroscopy, and therefore, studies are limited to fairly small and simple molecules. However, these techniques are not restricted to polar molecules as is the case for microwave spectroscopy, and thus infrared and Raman spectroscopy play an important role in the determination of the structures of small symmetric non-polar molecules. The rotational constants, provided by high-resolution spectroscopic methods, are inversely proportional to the principal moments of inertia, I, defined such that

I a ≤ Ib ≤ Ic ,

(1)

where a, b and c denote the three principal axes of inertia. The rotational constants are given by A = h/8π2Ia, B = h/8π2Ib, C = h/8π2Ic

(A ≥ B ≥ C ),

(2)

where h denotes Planck's constant. Linear and spherical top molecules have two and three identical rotational constants, respectively. For a symmetric top molecule, two of the three rotational constants are equal; A > B = C for a prolate symmetric top, and A = B > C for an oblate symmetric top. For an asymmetric top molecule, there are three different rotational constants. For a rigid planar molecule, however, only two of the three constants are independent because of the relation Ic = Ia + Ib.

(3)

The inertial defect, defined as

∆ = I c – I a – I b,

(4)

has a small and, in most cases, positive value for many planar molecules and is accounted for mainly rotation-vibrational interactions. For most molecules, the number of independent geometric parameters exceeds the number of available independent rotational constants. Rotational constants of isotopically substituted species are used in these cases. The significance of the rotational constants depends on the contributions of intramolecular motions. For molecules with small amplitude intramolecular vibrations in the absence of accidental degeneracies or resonances, the rotational constants in the υ-th vibrational state are given as follows

4

1 Introduction

Bυ = B e − ∑ α sB (υ s + d s / 2) + ... ,

(5)

s

where υs and ds denote the vibrational quantum number and the degeneracy of the s-th normal mode, respectively. As can be seen, the ground vibrational state rotational constant, B0, is not identical with the equilibrium one, Be, which can be interpreted purely geometrically:

= Be h / 8π2 I b(e) .

(6)

The rotation-vibration interaction constants α sB are functions of the harmonic (quadratic) and anharmonic (mainly cubic) force constants [26] and depend on the masses of the component atoms. If the α sB constants are derived in harmonic approximation, the Bz constants can be determined as follows:

Bz = B0 + ∑ a sB (harm) ⋅ d s / 2 = h / 8π2 I b( z ) .

(7)

s

The α sB constants can be obtained from the rotation-vibrational spectra and/or the rotational spectra in excited vibrational states. The equilibrium rotational constants can be determined, if all the α sB constants are known. This method is often hindered by Fermi resonances, i.e. anharmonic or harmonic resonance interactions in excited vibrational states, or by Coriolis resonances. Due to enormous efforts, the experimental equilibrium rotational constants are known only for a limited number of simple molecules. For the more precise determination of equilibrium rotational constants, the small effects of centrifugal distortion as well as the electronic corrections, ΔBel, can be taken into account [27]. The electronic correction may be obtained from the rotational g tensor [28] via the following formula: ΔBel = ‒(me/Mp)gBe,

(8)

where me and Mp are the masses of the electron and the proton, respectively. The ΔBel contributions are often negligible, being of two orders of magnitude smaller than the vibrational effects. Alternatively to the experimental determination of all rotation-vibration interaction constants α sB , the sum of these constants, i.e. rovibrational corrections to the experimental ground-state rotational constants ΔBe = Be ‒ B0, can be estimated by theoretical methods. For rigid and semi-rigid molecules, vibrational effects are usually treated using second-order vibrational perturbation theory [26,29] and estimated from the force fields (up to cubic terms) calculated by quantum-chemical (QC) methods (see reviews [30,31] and references therein). The accuracy of calculated ΔBe values can be very high, at least for molecules containing first-row elements, namely their relative errors are estimated to be only a few percent, if the force fields are calculated at the coupled-cluster level of theory in conjunction with a basis set at the convergence limit (see, for instance Ref. [32]). The propagated errors in the equilibrium bond distances are estimated to be only a few thousandths of an Å unit [33]. Some examples for the accurate determination of equilibrium structure from the ground-state rotational constants and computed rovibrational corrections as well as for benchmarking of the method can be found for instance in Refs. [34-38]. The least-squares

1.2 Short Description of Experimental Methods

5

methods (ordinary, non-linear, weighted, mixed regression, etc.) applied in the structure determinations from spectroscopic constants are described in Ref. [39] (see also references therein). In a non-rigid molecule, the large amplitude intramolecular motions (such as internal rotation, inversion, ring puckering, etc.) are considered separately from the small-amplitude vibrations (adiabatic approximation). Even in the borderline case of weakly bound complexes with labile motion of their components with respect to each other, it is possible to determine the ground-state rotational constants. Without going into a detailed numerical analysis of the rotational constants, the spectroscopic methods can indicate the presence of symmetry elements in a molecule. When the spectrum of a symmetric top appears regular, it is easy to show that the molecule has a Cn symmetry axis with n ≥ 3. The statistical weight due to degeneracy of nuclear spins can supply additional information. Even for an asymmetric top a C2 axis causes intensity alternations in its spectrum. A plane of symmetry can be detected by isotopic substitution of one of two atoms located symmetrically with respect to the plane. A small inertial defect indicates that a molecule has planar or close to planar equilibrium configuration. Gas Phase Electron Diffraction. In 1930, i.e. a few years after the first electron diffraction experiments on solid samples, the strong interference effects in the electron scattering intensity were observed by Mark and Wierl [40] for randomly oriented molecules of a gaseous tetrachloromethane sample. These effects depend on the internuclear distances in the molecule and, consequently, allow the determination of the molecular structure. The main units of the conventional GED apparatus are an electron gun, a focusing system, the sample injection system and the detector with a rotating sector above it (see Ref. [41] and references therein). The electron beam is focused by means of diaphragms and electromagnetic lenses. The rotating sector (with an opening proportional to the cube of its maximal radius) is used to compensate for the rapid decrease (reciprocally proportional by fourth power) of the electron scattering intensity. In the GED experiment, the sample gas is inserted into the diffraction chamber through a nozzle, and the electron scattering by the molecules near the nozzle tip are registered by the detector. The currently used instruments are either improved commercial gas electron diffraction equipment, such as a Balzers Eldigraph KD-G2 [42], or adapted commercial electron diffractometer originally built for studies of solid samples, such as EMR100 [43]. Photographic plates or films are still used for the registration of the diffraction patterns, whereas they can be replaced by image plates without set-up of an electron diffractometer [42,44-46]. The photographic density (with linear interval from about 0.2 to 0.8) is measured by a microphotometer or scanner and converted to electron intensity by means of a calibration function. The functionality of image plates is based on the photostimulated luminescence effect. At the registration by image plates with radiationsensitive layers, the electron scattering pattern, stored due to the excitation of europium ions, are recov-

6

1 Introduction

ered as a blue luminescence stimulated by red laser light. The number of the emitted photons is proportional to the locally absorbed electron dose, and the response of an image plate reader is linear [46]. The main experimental conditions of conventional electron diffraction experiments are the following: the electron wavelength determined by the accelerating voltage between 40 and 100 kV; electron beam diameter, ≈0.1 mm; nozzle diameter, ≈0.3 mm; nozzle-to-detector distance, ≈20…60 cm; sample pressure at the nozzle tip, between a few tenths of Torr to a few Torr; nozzle temperature, from room temperature to several hundred of degrees; the pressure in the diffraction chamber, about 10-6-10-5 Torr. The stability of the electron wavelength during the experiment is usually required to be better than 0.1%. The measurements of the electron wavelength can be carried out in a complementary investigation of molecules in the gas phase (e.g., benzene and tetrachloromethane) or polycrystals (e.g., ZnO) with well-known internuclear distances or lattice parameters, respectively. The total intensity of electron scattering, IT, is a function of the scattering variable, s = (4π /λ) sin (θ /2),

(9)

where λ is the electron wavelength and θ is the scattering angle. It includes a background, IB, and the molecular term, IM: IT = IM + IB,

(10)

where IB = Iatomic + Iinelastic + Iextraneous ,

(11)

I M ( s ) =ΣΣgij ( s ) exp(− 12 uij2 s 2 ) sin s (ra,ij − κ ij s 2 ) / sra,ij .

(12)

i≠ j

In Eq. (12), ij are the atom pairs in the molecule, gij(s) are the atomic scattering functions, ra,ij are the internuclear distances, uij are the root-mean-square (r.m.s.) vibrational amplitudes, κij is the asymmetry parameter (for more details, see for instance Ref. [47] and references therein). The relation between κij and anharmonic constant can be expressed for polyatomic molecule as follows [48]:

κij = (aij〈Δz2〉 T ,ij /6)(3 ‒ 2〈Δz2〉 0,ij /〈Δz2〉 T ,ij ), 2

2

2

(13)

where aij is the Morse constant, 〈Δz2〉 T ,ij and 〈Δz2〉 0,ij are the parallel mean square amplitudes of vibration 2

2

at temperature T and 0 K, respectively. The relation between the constant aij and the third order (cubic) force constant frrr in internal coordinates can be expressed, for instance for the linear triatomic molecules, as: [49] a = ‒2 frrr/(fr ‧ re),

(14)

where re is the equilibrium distance and fr is the stretching force constant. The thermal average internuclear distances rg are related to the ra values by: rg,ij = ra,ij + uij2/ra,ij The reduced molecular constituent of electron scattering intensity

(15)

1.2 Short Description of Experimental Methods

7

sM(s) = [IT(s) ‒ IB(s)] ‧ s /IB(s)

(16)

is used to determine the geometrical parameters of the molecule, the r.m.s. amplitudes and sometimes the asymmetry parameters κij by the least-squares method. The quality of the fit of the theoretical sM(s) function, calculated for the adjusted molecular model, to the experimental sM(s) is characterized by the goodness factor usually characterized as:

[∑ wi (sM (s )i exp − sM (s )i theor ) 2 / Rf = i

∑ w (sM (s) i

i

i

exp 2 1 / 2

) ]

× 100% ,

(17)

where wi is the weight of the point i. In detail, the theory of the conventional GED method is described for instance in Refs. [47,50,51]. In comparison with rotational spectroscopy, the GED method has the following advantages: a) this method allows the direct determination of internuclear distances; b) in principle, there are no requirements concerning properties of the sample molecules, except for chemical stability and sufficient vapor pressure, i.e. both small and large (up to 137 atoms in this book [52]), both light and heavy, both polar and nonpolar molecules can be studied by this method. However, the GED method has the following drawbacks: a) the refined parameters are averaged over all vibrational states in thermal equilibrium, i.e. affected by vibrational effects which can be very large (for instance at high temperatures as well as in non-rigid molecules) and have different magnitude for different internuclear distances; b) as a result of (a), the thermal-average structure is trigonometrically inconsistent; c) the solution of the inverse problem, i.e. determination of the structure by fitting the calculated scattering intensities to their experimental counterpart, can be ambiguous; d) due to vibrations, the close-spaced bond distances cannot be resolved (within some hundredths of Å), and only the nonbonded distances can increase their resolution; e) the distances between the atoms with very different atomic numbers cannot be determined precisely, e.g. C‒H bonds; f) the conformational analysis can be impossible even for two conformers, if the specific terms, characterizing each conformer, are close to each other; g) as a consequence of (a) and (b), the point-group symmetry of the molecule cannot be determined, the overall symmetry of molecule is assumed in many GED studies; h) due to high correlation between some refined parameters, the determination of the full set of geometrical parameters as well as r.m.s. amplitudes is very often not possible. To study transient chemical species, the ultrafast electron diffraction (UED) (time-resolved electron diffraction (TRED) is used as synonym) has been developed (see Refs. [53-55] and references therein) after pioneering work of A. A. Ischenko et al. in 1983 [56]. The UED method has been explored by Wilson and co-worker theoretically [57] and by Zewail and coworker experimentally [58]. The modern technique generates timed sequences of ultrafast pulses, namely, a femtosecond laser pulse to excite the sam-

8

1 Introduction

ple molecules and ultrashort electron pulses to probe the ensuing structural changes. Direct imaging is achieved using charge coupling device (CCD) camera [59,60]. Because of the formidable experimental challenges, there are still only a few molecular structures studied by the UED method. In comparison with conventional GED, the UED experiments are currently able to achieve spatial resolution of 0.01 Å [61]. Moreover, the short-lived species as well as the chemical reactions can be studied by this method. Electron Diffraction Augmented by Data from Other Methods. The drawbacks of gas electron diffraction can be significantly reduced if data from other methods are used conjointly. Vibrational spectroscopy can be used as source of the force constants, which are required for the estimation of r.m.s. amplitudes and vibrational corrections to thermal-average internuclear distances. Increasingly, the force fields are taken from quantum chemical (QC) computations due to their appropriate accuracy [32]. The point-group symmetry can be assumed according to data of vibrational and rotational spectroscopy as well as according to results of high-level QC calculations. The rotational constants determined by high-resolution spectroscopy can be used to stabilize the solution of the inverse problem of the electron diffraction method. As a result, the structure can be determined with less ambiguity and more accuracy than by electron diffraction alone [62].

In order to be used jointly, the data from different methods have to be compatible (i.e. of the same physical meaning). In this respect, the equilibrium structure, re (see Sec. 1.3), seems to be most appropriate because this structure, corresponding to the minimum of the potential energy surface (PES), is also a result of quantum chemical optimization. Decreasingly, the combined analysis of electron diffraction data 0

and rotational constants is based on equivalent structures r α ≡ rz (see Sec. 1.3). In most structural studies, particularly of conformational mixtures and very complex overcrowded molecules with many structural parameters, differences between related geometrical parameters as well as some parameters themselves are assumed or constrained to the values from QC computations. There are some methods suggested for the analysis of GED data in combination with QC restraints: MOCED (Molecular Orbital Constrained Electron Diffraction), SARACEN (Structure Analysis Restrained by Ab initio Calculations for Electron diffractioN), DYNAMITE (DYNAMic Interaction of Theory and Experiment), SEMTEX (Structure Enhacement Methodology using Theory and Experiment), etc. (see review paper [63] and references therein). The support of electron diffraction by mass spectrometry (MS) is very important at decomposition of the sample molecules [41]. I. Hargittai et al. [64,65] and latterly G. V. Girichev et al. [66,67] have pioneered the use of GED with MS. Determination of Equilibrium Structure from Electron Diffraction Data. Increasingly, the GED structural analysis is carried out in terms of the equilibrium structure. In many cases, the thermal average

1.2 Short Description of Experimental Methods

9

structures rg or ra of a rigid or semirigid molecule are converted to the equilibrium one, re, by taking into account vibrational corrections calculated in curvilinear coordinates, i.e. with nonlinear transformation of the Cartesian coordinates into internal ones (so-called “kinematic anharmonicity”), from QC harmonic (quadratic) and anharmonic (usually only cubic) force constants (i.e. from the second and third derivatives of energy). The contribution due to centrifugal distortion δcent [68] is also included into total corrections to the experimental internuclear distances, Δre = ra ‒ re. It should be noted that this correction is in a simple relation with Δre = rg ‒ re difference (see Eq. 15), which have clear physical meaning. In some cases, the re structures are denoted by Δra3,1 following the suggestion of McCaffrey et al [69]. Two alternative procedures are suggested to obtain an equilibrium structure from GED data. In the first one, the conventionally refined ra distances are subsequently converted into re values by subtracting of vibrational corrections (see, for example, estimated equilibrium structures denoted as r eM [70]). This procedure was suggested by Morino, Bartell, Kuchitsu and their coworkers [71-75] several years ago. If vibrational corrections are estimated for all independent internuclear distances in the molecule, the conversion of ra to re can be done on each step of the GED fitting. Thus, the complete set of trigonometrically consistent equilibrium structural parameters can be refined. Very often, vibrational corrections are calculated from quantum chemical force fields using the method suggested by Sipachev [76-78]. In flexible molecules, the large-amplitude vibrations adiabatically separated from small-amplitude vibrations are usually described by a model of pseudo-conformers using Boltzmann distribution according to the potential energy function (PEF) or PES assumed or taken from QC computations (see, for example, applications in Refs. [79,80]). Alternatively, the method of molecular dynamics (MD) simulations [81,82] can be useful for estimation of vibrational corrections (denoted as Δre,MD) for very flexible molecules, for which the force field calculations are inaccurate. The alternative method was developed by Spiridonov and coworkers (see review papers [83,84] and references therein). In the suggested algorithm, the equilibrium distances and force constants can be simultaneously refined directly from GED data. The expressions for the molecular scattering intensity in terms of parameters of PEFs, expanded through cubic terms in normal coordinates, were obtained for some small symmetric molecules using first-order perturbation theory (see Refs. [85,86] for triatomic molecules). However, the determination of equilibrium structure and force constants from electron diffraction data alone is possible only for the simplest molecules and only when the quality of measured intensities is enough to determine anharmonic force constants with appropriate uncertainties (see, for example, Ref. [87]). Therefore, the force fields are usually taken from QC calculations. Furthermore, the cumulant-moment method, based on the relations between the cumulants defined with respect to the Pij(r)/rij function and parameters of PEF expanded through cubic (or quartic) terms was suggested in Refs. [88,89]. The method developed by Spiridonov et al. was later extended by Kochikov et al. for the study of polyatomic molecules with one or more large-amplitude motions [90,91]. The suggested approach includes

10

1 Introduction

the analysis of the molecular Hamiltonian and adiabatic separation of different molecular degrees of freedom. The applications of the dynamic model describing the multiple large-amplitude motions are presented in Refs. [92,93]. Because the computations of anharmonic force fields are rather time-consuming tasks, particularly for large and non-symmetric molecules, the anharmonicity effects have not been taken into account in many structure determinations. If vibrational corrections to experimental internuclear distances are calculated using only harmonic (quadratic) force field, the derived structure is denoted as rh1 (harmonic in curvilinear coordinates) and the total corrections to ra as Δrh1 = ra ‒ rh1 (first-order curvilinear corrections). If kinematic anharmonicity is also neglected, the rh0 structure (harmonic in rectilinear coordinates) is determined with Δrh0 = ra ‒ rh0 corrections (zeroth-order rectilinear corrections). Thus, the rh0 and rα structures have equivalent significance. The rectilinear corrections [94,95] are rather inaccurate and lead to dramatically deformation of the refined structure as they over-correct the bonded distances and under-correct the nonbonded distances. In a few cases, zeroth-order rectilinear corrections are taken into account together with dynamic anharmonicity effects (see, for example [96]). The rh1, rh0 and rα structures are assumed to be trigonometrically consistent. The structures, determined from experimental data by taking into account vibrational corrections estimated by theoretical methods, are not completely experimental. In spectroscopy, such equilibrium structures are called semiexperimental (or semiempirical) ones. In electron diffraction literature, this point is usually not emphasized, although all structures derived from experimental data and QC force fields (both harmonic and anharmonic) indeed belong to this category. 1.3 Significance of Geometric Parameters The molecular structures presented in this book have different meanings. The structure type definitions are based on physical principles or derived operationally, i.e. depending on the method used to obtain the structural parameters from the experimental data. A short description of the structure types presented in this book is given below. For more details, see for instance Introduction to Ref. [10] and Refs. [97,84,10,98]. In Spectroscopy. In most spectroscopic studies, nuclear positions in the principal axis system are directly derived from the rotational constants, and bond distances and angles are then calculated from the determined coordinates. Contrary to that, the internuclear distances being arguments of intensity function sM(s) are primary determined by GED, whereas the angles or nuclear coordinates are derived from the internuclear distances. Beside the conventional r0 or rs structures, operationally derived from spectroscopic experiments, the equilibrium structures re with well-defined physical meaning are also presented in many original papers. It is worth noting that the number of the equilibrium structures is continuously increasing in the literature.

1.3 Significance of Geometric Parameters

11

(a) r0 structure: It is derived from a set of bond coordinates obtained by a least-squares fitting of ground-state inertial moments I0 of a set of isotopic species. The ground-state rotational constants do not correspond to the moments of inertia averaged over the ground vibrational state, but rather their inverses. Therefore, the r0 structure does not have clear physical meaning. The relation Ic = Ia + Ib for a planar molecule does not strictly hold for the ground-state rotational constants. (b) rs structure: It is derived from a set of atom coordinates obtained from the differences of inertial moments ΔI upon isotopic substitution. Following Costain [99], the rs structure should be more accurate and consistent than the r0 structure. Kraitchman’s equations [100] are used most conveniently for the determination of the rs structure. For a linear molecule the coordinate of the i-th atom ai is given by ai2 = ∆ I b / µ ,

(18)

where ∆Ib is the change in the moment of inertia of the i-th atom upon substitution, atom has a mass differing from the original atom by,

µ = M∆mi/(M+∆mi),

(19)

where M is the total mass of the parent molecule, ∆mi is the change of the atom mass relative to that in the parent molecule. For a general asymmetric top, Kraitchman gave the following equation:

= ai2

∆Pa

1 − ∆Pb / ( Pa − Pb )  1 − ∆Pc / ( Pa − Pc )  . µ 

(20)

Equations for bi2 and ci2 are obtained by cyclic permutation of a, b and c. The moment Pa is defined by

Pa = (− I a + I b + I c )/2 ,

(21)

Pb and Pc being defined in a similar way, and ∆P denotes the change of P on isotopic substitution. When a molecule has a plane or axis of symmetry, the corresponding equations are simpler. All the singly substituted isotopic species are required for determination of a complete rs structure. However, this is impossible for the molecules containing atoms having only one stable isotope, such as 19

F, 31P, 127I, or can be difficult because of problems to make complete isotopic substitutions. The coordi-

nates of the atoms located close to an inertial plane are poorly defined, irrespective of the atomic mass. For small coordinates, doubly-substituted species may be of some use [101,102]. As recently shown, the Kraitchman method can fail in the determination of accurate structure of polyatomic molecules [36,103]. (c) rz structure: Temperature-independent average structure defined by the average nuclear positions in the ground vibrational state is usually called rav or rz [104-107]. This structure is derived, when the Bz rotational constants (see Eq. (7)) are used instead of B0. For a rigid molecule

12

1 Introduction

rz ≅ re + ∆z 0 ,

(22)

where ∆z denotes the instantaneous displacement, ∆r, of r(X−Y) projected on the equilibrium X−Y axis (taken as a temporary z axis), and 0 denotes the average over the ground vibrational state. se

(d) re, r e structure: Equilibrium structure corresponds to the minimum of PES. The equilibrium rotational constants Ae, Be and Ce can be derived from the experimental data alone, if all the rotation-vibration interaction constants, α sA , α sB and α sC , given in Eq. (5) are determined. To obtain the complete equilibrium structure re, a sufficient number of equilibrium rotational constants should be available. Due to enormous efforts, the equilibrium structures determined from spectroscopic data alone are relatively rare and known only for a few small and simple molecules [108]. Alternatively, the sum of the rotation-interaction constants, i.e. ∆Be = Be − Β0, can be estimated with high accuracy by theoretical methods using harmonic (quadratic) and anharmonic (mainly cubic) force constants from high-level QC computations. In the literse

ature, such structure is called semiexperimental (or semiempirical) equilibrium structure, r e . (1)

(2)

(e) rm, r m , r m structures: Mass-dependent structure rm proposed by Watson [109] is determined from a fit of structural parameters to the mass-dependent moments of inertia Im = 2Is − I0. In a number of examples, Watson has shown that the rm structure is indeed very close to the re structure, except for some (1)

(2)

parameters involving hydrogen. The mass-dependent r m and r m structures are based on different dependences of the inertial moments and their rovibrational contributions on the atomic masses. In Electron Diffraction. An average distance between an atom pair corresponds to the first moment of the probability distribution function of this distance, P(r). The P(r) function is approximately Gaussian unless the distance depends strongly on a large-amplitude vibration [71]. (a) ra internuclear distance, directly derived from experimental data, corresponds to the center of gravity of the P(r)/r distribution [73-75]:

ra = ( ∫ P (r ) dr ) / [ ∫ ( P (r ) / r ) dr ] ,

(23)

if the asymmetry parameter κ in Eq. (12) is negligibly small. The effective angles derived from the ra distances are denoted as θa. (b) rg distance corresponds to the center of gravity of P(r) distribution, if the parameter κ in Eq. (12) is close to 0:

= rg [ ∫ rP (r )dr ] / [ ∫ P (r )dr ] ≅ ra + u 2 / ra ,

(24)

where u is the r.m.s. amplitude. The θg angles derived from rg distances are not physically meaningful due to shrinkage effects. (c) rα distance is derived [110,111] from the corresponding rg distance as follows:

1.3 Significance of Geometric Parameters

(

rα = rg − ∆x 2

T

+ ∆y 2

T

13

) / 2r − δ r ,

(25)

where ∆x and ∆y are the displacements perpendicular to the equilibrium nuclear axis (z) and δr is a small displacement due to centrifugal force. The angle derived from the rα distances is denoted as θα. The rα structure is considered as trigonometrically consistent due to elimination of shrinkage effects. The rα distance corresponds to the distance between the thermal-average nuclear positions: rα ≅ re + ∆z

T

.

(26)

(d) r 0α distance is derived due to extrapolation of rα to zero Kelvin temperature: r 0α = lim rα ≅ re + ∆z T →0

(27)

0

The r 0α structure is practically equivalent to the rz one. The numerical difference between the rα and r 0α distances can be negligibly small, except for the case of large amplitude motion, when harmonic approximation is not applicable at all. (e) re internuclear distance is a distance between the equilibrium nuclear positions corresponding to the minimum of PES. The re distances can be estimated from experimental distances ra if anharmonic vibrational corrections Δranh are known: re = ra + u2/ra ‒ Δranh ‒ δr

(28)

The Δranh values are usually calculated from quadratic and cubic force constants accounting for nonlinear kinematic effects (see also Sec. 1.2). The higher order anharmonicity of large-amplitude vibrations is estimated according to the shape of the PEF (or PES). If the force field is taken from theoretical comse

putations, the re structure is sometimes called semiexperimental equilibrium structure, r e . (f) rh1 is a distance derived from ra taking into account harmonic vibrational corrections and nonlinear kinematic effects Δrh1 (see also Sec. 1.2): rh1 = ra + u2/ra ‒ Δrh1 ‒ δr.

(29)

A short description of parameters mentioned above is comprised in Table 1. Table 1. Definitions of parameters Symbol

Definition

rg

Thermal average value of internuclear distance

ra

Constant argument in the molecular term, Eq. (12), equal to the center of gravity of the P(r)/r distribution function for specified temperature

re or r e

Distance between equilibrium nuclear positions

rα, rh0

Distance between average nuclear positions (thermal equilibrium), derived from rg/ra taking into account harmonic vibrational effects

rh1

Distance between average nuclear positions (thermal equilibrium), derived from rg/ra

se

14

1 Introduction

taking into account harmonic vibrational effects and non-linear kinematic effects rz , r 0α

Distance between average nuclear positions (ground vibrational state)

r0

Distance between effective nuclear positions derived from rotational constants of zeropoint vibrational levels

rs

Distance between effective nuclear positions derived from isotopic differences in ground-state rotational constants

rm

Distance between effective nuclear positions derived by the mass-dependence method of Watson, very close to re for molecules without hydrogen atoms.

(1)

(2)

rm ,rm

rm distances obtained with different dependences of inertial moments and their rovibrational contributions on the atomic masses.

Concluding remarks. Numerical differences between parameters of different types may not necessarily be important within the experimental uncertainties (for instance between rg and rh1). In general, for correct comparison of data from different determinations in order to get adequate conclusions, it is always important to specify their significance. It was not possible and not necessary to present in the following tables the structures of all types. The semiexperimental equilibrium structures are preferred to the structures corrected only for harmonic vibrational effects, such as rz, rα, r 0α , rh0, rh1. However, a few exceptions are made to show the magnitudes of discrepancies between these structures.

1.4 Uncertainties Uncertainties in the structural parameters are taken from original papers. In Structures Determined by Electron Diffraction. The total errors in structural parameters, σtot, are usually estimated as: σtot = (σrand2 + σsyst2)1/2,

(30)

where σrand are random errors and σsyst are systematic errors.

Random errors are estimated in a least-squares analysis from differences between the observed intensity and its theoretical counterpart. The least-squares deviation (σ) is usually multiplied by a certain constant (up to 3) according to the significance level (up to 99.7%). The estimated random errors indicate relative errors in the structural parameters of the molecule. In many cases, they are about 0.1% of distance and can be reduced to 0.01% [112]. Systematic errors can be classified as experimental and analytical. The experimental sources of the errors are mainly the measurements of IM(s) including measurements of electron wave length, camera distance, as well as the sector calibration, etc. The experimental systematic errors are different from laboratory to laboratory. In many cases, they are estimated to be 0.1% or 0.2% of the refined internuclear distances.

1.4 Uncertainties

15

Analytical systematic errors arise due to the application of the theoretical model (rigid or non-rigid, harmonic or anharmonic, etc.), which can be more or less adequate for the description of molecular dynamic, as well as due to assumptions made in structural analysis (for instance with respect to background, point-group symmetry, differences in the structural parameters, etc.). The estimation of these errors is very difficult or even impossible. Therefore, they are rather underestimated than real. Thus, systematic errors can be comparable or even significantly larger than the random ones. In principle, a real accuracy of different experimental methods can be estimated by comparison of the determined structures, as long as they have the same physical meaning. Benchmark determinations of semiexperimental equilibrium structures by GED augmented by high-level ab initio calculations (for instance of maleic anhydride [113], uracil [103], picolinic acid [114], etc.) have shown that the accuracy can reach a few thousandths of Å for the bond distances and a few tenths of degree for the bond angles. Many examples can be found also in the following tables. The accuracy of the structures determined from rotational constants can be higher than that obtained from the GED data by one order of magnitude [103]. The values of uncertainties in the structural parameters are taken from original papers without changes. In Structures from Spectroscopy. In many cases, the given uncertainties in the structural parameters are derived only from the experimental errors in the rotational constants. Since rotational constants are determined with six to eight significant digits, this source of error is very small in comparison with systemse

atic errors. For the re and r e structures, systematic errors due to vibration-rotation interactions are also estimated and taken into account in some cases. The systematic error due to conversion of B0 to Be may contribute to the total uncertainties, which are roughly estimated to be a few parts in 103 or less. The uncertainties of the structures determined by spectroscopic methods seem to be smaller by one order of magnitude in comparison to those of the GED method. In many cases, however, the meaning of uncertainties was not specified in original papers. Most probably, they are 1 values in many cases. 1.5 Presentation of data General remarks. Structure data of 972 molecules are presented in Chapters 2-10. Chapter 2 includes data of 154 inorganic molecules except for a few inorganic molecules containing carbon atoms, such as carbon disulfide, carbonic difluoride, carbonic acid, etc. The inorganic molecules containing carbon atom(s) are implemented in the parts presented organic and organometallics molecules in the sequence of sum formulae in Hill system (see below). Structure data of 818 molecules containing at least one carbon atom are accumulated in Chapters 3-10. The data for molecules with one to six carbon atoms are presented in Chapters from 3 to 8, respectively, whereas Chapter 9 includes the data for molecules containing seven, eight or nine carbon atoms and Chapter 10 presents the structural parameters for all remaining molecules, i.e. with 10 or more carbon atoms.

16

1 Introduction

All information for each molecule including its possible conformers is listed together in a separate entry (document). The structures of molecule determined in different studies are presented in the same document. Different isomers or tautomers are presented separately (in different documents). Each molecule is identified by its chemical name(s), structural formula and sum formula listed on the right side in the beginning of the entry, whereas the item, Chemical Abstract Registry number (CAS RN) as well as the compound number in the MOGADOC database [115,116] (MGD RN) are given on the left side. In a few cases, the CAS RN is not stated because it has not been registered in the CAS database. After the method(s) of structure determination (in abbreviated form) on the left side and the determined or assumed point-group symmetry on the right side, the tables present the structural parameters: bond lengths and sometimes non-bonded internuclear distances, (bond) angles and dihedral angles as well as some special angles such as tilt, rock, etc. The numerical values of structural parameters are taken from the original papers cited in the end of each entry. Notation for the granted copy-right permission of the corresponding publisher is given directly below the reused or adapted table. All reviewed references are also listed together in the end of each chapter. They are presented in the same sequence as the molecular entries. Because some papers report the data for more than one compound, multiple listings of references occur. Further information is added in remarks and footnotes, followed by the references to the original papers used as source of information.

The structures determined in different studies are presented separately in the same document with identification of the method(s). All reviewed compounds are listed in Appendix. Order of Molecules. All 972 molecules are consecutively numbered from 1 to 972 along the Chapters 310. In each chapter, the molecules are arranged in alphabetical order of the sum formula in Hill system [117]. According to this system, each formula starts with carbon and hydrogen (if available) followed by the remaining element symbols in alphabetical order. Nomenclature. The names of molecules are mostly taken from the original papers, but an attempt is made to follow the usage in Chemical Abstracts and the rules of IUPAC (International Union of Pure and Applied Chemistry). Therefore many molecules have more than one name. A complex or an addition compound consisting of n, m,... atoms or molecules is indicated by the notation (n / m /... ), e.g., argon – hydrogen bromide (1/1). Tables and Comments. (a) The structure type is denoted as summarized in Table 1 and described in Sec. 1.3. A few other rare notations of equilibrium structure, such as r eM , re,MD, etc., are identified in the comment given in the entry.

1.5 Presentation of data

17

b) Atoms of the same kind are distinguished, if necessary for parameter definition, by numbers or letters given in parentheses, such as C(1), C(b), C(t) or sometimes designated by primes, e.g., C(1'), H'. c) Internuclear distances are represented by solid lines for the pairs of directly bonded atoms (e.g., C(1)–H), and by dotted lines for the non-bonded or weakly bound atom pairs (e.g., N(1)...N(2)). The bond orders of the single (as well aromatic), double and triple bonds are indicated by single (–), double (=) and triple (≡) lines, respectively, if the discrimination of the bond order was possible. The (bond) angles and dihedral angles are presented correspondingly (e.g., C≡C–O, C…C–O, C–C=C–C). Some dihedral and other angles (e.g., tilt angle) are defined in the corresponding footnote. Distances are given in Å (1 Å = 0.1 nm = 100 pm); angles are given in degrees. Uncertainties in structural parameters given in parentheses are applied to the last significant digit of the parameter values. d) The point-group symmetry is presented below sum formulae. This is the symmetry of the nuclear framework at stable equilibrium, corresponding to the minimum of the PES. This minimum is considered as the reference point of the displacements used to describe the internal motions of the atoms in the molecule. There are 3N–6 vibrational degrees of freedom for a nonlinear molecule containing N atoms and 3N–5 for a linear molecule. The whole potential surface, in general, has several minima corresponding to different stable conformations of the molecule. In non-rigid molecules it may be quite difficult to establish the point-group symmetry at stable equilibrium - particularly when the potential barriers between minima do not even rise above the zero-point levels. If the potential barriers between minima are sufficiently low, the internal molecular motions may become delocalized over several potential minima, either by passing classically over the barrier or tunneling through them quantum-mechanically. The symmetry of the molecular structure corresponding to a PES maximum between equivalent shallow minima, i.e. effective symmetry, can be very useful in such cases, for instance for the description of weakly-bound complexes. In many cases, however, it is not clear, whether the indicated symmetry is property of effective or equilibrium structure of the complex. The symmetry of the molecule is sometimes deduced by electron diffraction, but in many cases it is assumed. Spectroscopy is often a better source of experimental information on symmetry. There are, however, a lot of borderline cases. For example electron diffraction data are often found to be "consistent" or "compatible" with a model of certain symmetry. Very often, the point-group symmetry is assumed according to results of QC computations. e) The determined or estimated barrier heights are annotated in the comments. The energy differences between the studied conformers are also presented in many cases. They are listed in units used in original papers, i.e. in kcal mol‒1, kJ mol‒1 or cm‒1. The interconversion factors between these units are the following: 1 kcal mol‒1≈ 4.184 kJ mol‒1 ≈ 349.76 cm‒1 [118]. f) Temperature (for electron diffraction data): the thermal-average structural parameters are depending on the effective vibrational temperature of the sample molecules. Vibrational corrections to internuclear

18

1 Introduction

distances and r.m.s. vibrational amplitudes are also functions of temperature. The vapor composition is also depending on the temperature. In many cases, the measured nozzle temperature (abbreviated as Tnozzle or Teffusion cell (in K)) is close to the effective temperature of molecules. g) Methods and basis sets used in quantum chemical (QC) computations are mentioned (in abbreviated form), if the results of these calculations were used in the structural analysis of experimental data. As the accuracy of the semiexperimental structures is noticeably affected by the accuracy of the computed vibrational corrections, the level of the force field calculations is also indicated. In the electronic structure theory based on the Born-Oppenheimer approximation, the ab initio methods are defined by the expansion of the many-electron wavefunction, whereas the Kohn-Sham density functional theory (DFT) [119] method is defined by the choice of an exchange-correlation functional. In reviewed publications, the DFT calculations are very often performed with the Becke three-parameter hybrid exchange functional [120] and the Lee-Yang-Parr correlation functional [121] (together denoted as B3LYP). In many cases, the DFT calculations are carried out with the double hybrid functional which combines exact Hartree-Fock (HF) exchange with an MP2-like correlation (B2PLYP) including Grimmeꞌs dispersion correction [122], as well as with a hybrid meta exchange correlation functional with double the amount of nonlocal exchange (M06-2X) [123,124]. The so-called PBE (Perdew, Burke, Ernzerhof) [125,126] generalized gradient functional with a predefined amount of exact exchange, PBE0, [127] was also applied in many studies. The ab initio method most frequently used in the reviewed structure determinations is one at the level of the second-order Møller-Plesset perturbation theory (abbreviated as MP2) [128]. The high accuracy coupled cluster method with single and double excitations [129] and a perturbative treatment of connected triples (CCSD(T)) [130] is increasingly used in spite of very high costs.

The basis set is defined by the expansion of the one-electron orbitals. The basis sets, most commonly used in the reviewed papers, are the following: the correlation-consistent polarized valence n-tuple basis sets (cc-pVnZ, n = T,Q,5) [131-133], originally developed by Dunning for the first-row atoms [134], as well as the correlation-consistent polarized core-valence n-tuple (cc-pCVnZ) [135,136] and the correlation-consistent polarized weighted core-valence (cc-pwCVnZ) [136] basis sets, sometimes including diffuse functions (aug) [137]; the Ahlrichsꞌs split valence (SV), triple- and quadruple-zeta valence (TZV and QZV) basis sets [138], the Popleꞌs split-valence, such as 6-31G, 6-311G basis sets [139,140], very often with polarization (* or **) and diffuse functions (+ or ++) [141], etc. The pseudopotential (PP) (or effective core potential (ECP)) approximation, originally introduced by H. Hellman [142], is widely used for molecular systems containing heavy atoms (see review paper by P. Schwerdtfeger [143] and references therein). The relativistic PP potentials, such as Stuttgart-DresdenBonn (SDB) and Stuttgart (SDD) [144,145], were also applied in some studies presented in this book.

1.5 Presentation of data

19

The calculations were carried out with all electrons being correlated (abbreviated as ae or full) or in “frozen core” approximation (fc, omitted by default). For more details concerning the methods of electronic structure theory and basis sets applied in the computations, see original paper cited in each document as well as Refs. [31,146-148] and references therein. Figures and Structural Formulae. Almost all molecules are represented by a structural formula with chemical symbols and a figure with ball-stick models, where the symbols of hydrogen atoms are often omitted. The labelling of atoms in the figure is the same as in the table, except for parentheses, which are usually omitted to save space. All figures have been created using our own computer program on the basis of data given in the tables. The special designations (numbers, letter characters, etc.) of individual atoms are assigned whenever necessary for discrimination. The atom numbering in the molecule is very often based on that given in the original papers, and is consistent with that used in the respective table. In some cases, however, it is modified to be consistent with the given chemical name. Moreover, the single-digit numbering was preferred for the hydrogen atoms represented by the smallest balls. Each bond between atoms in the molecule, except for hydrogen bonds, is presented in the figures by a single line. In many cases, the hydrogen and other weak bonds are also shown (by dotted lines). The auxiliary lines are also shown by dotted lines. In the structural formulae, the drawn single, double and triple lines connecting atoms are not necessarily correct representation of the bond orders. Source of Bibliographic Information. The MOGADOC ("Molecular Gasphase Documentation") database was used as a source of bibliographic information. For features of this database, see Refs.[115,116] Its current version contains ca. 45800 bibliographic references for microwave spectroscopy, molecular radio astronomy and gas phase electron diffraction since 1930 until 2017 referring to about 13700 structures fo r inorganic, organic and organometallic compounds. List of abbreviations.a CAS RN Chemical Abstracts Registry Number (for compound) DFT density functional theory (calculations) ECP effective core potential GED gas-phase electron diffraction FT Fourier transform (spectroscopy) IR infrared (spectroscopy) MD molecular dynamics (simulation) MGD RN registry number in MOGADOC database (for compound) MI matrix isolation (spectrum) MM molecular mechanics (calculations) MS mass spectrometry MW microwave (spectroscopy) NBO natural bond orbital (method)

20

1 Introduction

NMR PES PEF PP QC Ra UED TRED UV XRD

nuclear magnetic resonance potential energy surface potential energy function pseudopotential quantum-chemical (ab initio and DFT) Raman spectroscopy ultrafast electron diffraction time-resolved electron diffraction ultraviolet (spectroscopy) X-ray diffraction

ac ap ax b cm eq sc sp t

anticlinal antiperiplanar axial bridge center-of-mass equatorial synclinal synperiplanar terminal

a

For abbreviations of QC methods widely used in reviewed structure determinations, see Sec. 1.5.

List of References

21

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Chapter 2. Inorganic Molecules without Carbon Atoms 1

Silver iodide – argon (1/1)

CAS RN: 2127109-40-2

AgArI C∞v

MGD RN: 537270 MW supported by ab initio calculations Distances Ar…Ag Ag–I

Ag

I

Ar

r0 [Å] a 2.6759 2.5356

Copyright 2017 with permission from Elsevier.

a

Uncertainties were not given in the original paper.

The rotational spectra of the van der Waals complex of silver iodide with argon were recorded by a chirpedpulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 109 Ag). The complex was found to be linear. Medcraft C, Mullaney JC, Walker NR, Legon AC (2017) A complex Ar⋅⋅⋅Ag–I produced by laser ablation and characterized by rotational spectroscopy and ab initio calculations: Variation of properties along the series Ar⋅⋅⋅Ag–X (X = F, Cl, Br and I). J Mol Spectrosc 335(5):61-67

2 CAS RN: 1629210-87-2 MGD RN: 405223 MW supported by QC calculations

Chloro(dihydrogen-H,H)silver Silver chloride – dihydrogen (1/1) AgClH2 C2v H Ag

Distances H–H Ag–Cl Rcm b

a

r0 [Å] 0.806(2) 2.261(7) 1.86(9)

Cl

H

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Distance between centers of mass in both monomer subunits.

The rotational spectra of the binary van der Waals complex of silver chloride with molecular hydrogen were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 26 GHz. The transient complex was produced by a gas-phase reaction of laser-ablated silver with chloride and hydrogen. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 109Ag, 37 Cl and 109Ag/37Cl). © Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_2

33

34

2 Inorganic Molecules without Carbon Atoms

Grubbs GS, Obenchain DA, Pickett HM, Novick SE (2014) H2-AgCl: A spectroscopic study of a dihydrogen complex. J Chem Phys 141(11): 114306/1-114306/10; erratum: J Chem Phys 143(2):029901/1-029901/2 (2015) [http://dx.doi.org/10.1063/1.4895904]

3 CAS RN: 848348-16-3 MGD RN: 215060 MW supported by ab initio calculations

Distances Ag–Cl Ag…O

r0 [Å] a 2.273(6) 2.198(10)

Angle

θ0 [deg] a

ϕ

b

Silver chloride – water (1/1) AgClH2O Cs Ag

Cl

O H

H

rs [Å] a 2.263(6) 2.204(10)

37.4(16)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit. Angle between the C2 axis of the water subunit and Ag…O.

The rotational spectra of the binary complex of silver chloride with water were recorded by a pulsed-jet BalleFlygare type FTMW spectrometer in the frequency region between 7 and 15 GHz. The transient complex was produced by expansion of H2O and CCl4 in the presence of laser-ablated Ag atoms. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, 109 Ag, 37Cl, 18O, D2, 109Ag/37Cl, 109Ag/18O and 109Ag/D2) under the assumption that the structural parameters of the water subunit were not changed upon complexation. Mikhailov VA, Roberts FJ, Stephens SL, Harris SJ, Tew DP, Harvey JN, Walker NR, Legon AC (2011) Monohydrates of cuprous chloride and argentous chloride: H2O⋅⋅⋅CuCl and H2O⋅⋅⋅AgCl characterized by rotational spectroscopy and ab initio calculations. J Chem Phys 134(13):134305/1-134305/12 doi:10.1063/1.3561305

4 CAS RN: 1321627-31-9 MGD RN: 212935 MW supported by ab initio calculations

Distances Ag–Cl Ag…S

r0 [Å] a 2.26882(13) 2.38384(12)

Angle

θ0 [deg] a

ϕ

b

Silver chloride – hydrogen sulfide (1/1)

78.052(6)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

AgClH2S Cs Ag

Cl

S H

H

2 Inorganic Molecules without Carbon Atoms b

35

Angle between the C2 axis of the H2S subunit and Ag–Cl.

The rotational spectra of the binary complex of silver chloride with hydrogen sulfide were recorded by a pulsedjet Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 15 GHz. The transient complex was produced by expansion of H2S and CCl4 in the presence of laser-ablated Ag atoms. The partial r0 structure was determined from the ground-state rotational constants of twelve isotopic species (main, 109Ag, 37Cl, D, D2, 109Ag/37Cl, 109Ag/D, 109Ag/D2, 37Cl/D, 37Cl/D2, 109Ag/37Cl/D and 109Ag/37Cl/D2) under the assumption that the structural parameters of the hydrogen sulfide subunit were not changed upon complexation. Walker NR, Tew DP, Harris SJ, Wheatley DE, Legon AC (2011) Characterization of H2S⋅⋅⋅CuCl and H2S⋅⋅⋅AgCl isolated in the gas phase: A rigidly pyramidal geometry at sulfur revealed by rotational spectroscopy and ab initio calculations. J. Chem. Phys. 135(1):014307/1-014307/10 doi:10.1063/1.3598927

5 CAS RN: 33937-65-4 MGD RN: 214142 MW supported by ab initio calculations

Silver chloride – ammonia (1/1) AgClH3N C3v Ag

Distances Ag–Cl Ag…N N–H

r0 [Å] a 2.26333(6) 2.15444(6) 1.0129 b

Angle H–N…Ag

θ0 [deg] a

rs [Å] a 2.2633(9) 2.1545(8)

Cl

N H

H H

113.48(2)

Copyright 2010 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed at the re value from CCSD(T)/cc-pVQZ calculations.

The rotational spectrum of the binary complex was recorded by a pulsed-jet laser-ablation FTMW spectrometer in the spectral range between 7 and 16 GHz. The partial r0 and rs structures were determined from the ground-state rotational constants of five isotopic species (main, 109Ag, 15N, 109Ag/15N and 15N/37Cl). Mikhailov VA, Tew DP, Walker NR, Legon AC (2010) H3N⋅⋅⋅Ag–Cl: Synthesis in a supersonic jet and characterization by rotational spectroscopy. Chem Phys Lett 499(1-3):16-20

6 CAS RN: MGD RN: 216055 MW supported by ab initio calculations

Silver fluoride – water (1/1) AgFH2O Cs (see comment)

36

2 Inorganic Molecules without Carbon Atoms

Distances Ag–F Ag…O

r0 [Å] a 1.985(11) 2.168(11)

Angle

θ0 [deg] a

α

b

Ag

F

O H

H

41.9(11)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Angle between the axis defined by the Ag, O and F atoms and the C2 axis of the water subunit.

b

The rotational spectra of the binary complex were recorded in a pulsed supersonic jet by an FTMW spectrometer. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, 109 Ag, 18O, 18O/109Ag, D, 109Ag/D, D2, 109Ag/D2/) under the assumption that the structural parameters of the water subunit were not changed upon complexation. The complex was found to be of Cs symmetry in equilibrium. In the zero-point state, however, it is effectively planar, undergoing rapid inversion between two equivalent structures. Stephens SL, Tew DP, Walker NR, Legon AC (2011) Monohydrate of argentous fluoride: H2O⋅⋅⋅AgF characterized by rotational spectroscopy and ab initio calculations. J Mol Spectrosc 267(1-2):163-168

7 CAS RN: 12249-56-8 MGD RN: 349976 MW

Silver hydrogen sulfide Silver hydrosulfide AgHS Cs S a

a

Bonds Ag–S S–H

r0 [Å] 2.31219(75) 1.375(15)

rs [Å] 2.313(20) 1.373(15)

rz [Å] 2.313713(99) 1.3472(18)

Bond angle Ag–S–H

θ0 [deg] a

θs [deg] a

θz [deg] a

92.49(81)

92.21(42)

Ag

a

H

93.120(90)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

The rotational spectra of silver hydrosulfide were recorded in a free-space absorption millimeter-wave spectrometer in the frequency range between 192 and 312 GHz. The transient species was produced by a DC glow discharge with hydrogen sulfide and sputtering from silver sheets. The r0, rz and rs structures were determined from the ground-state rotational constants of four isotopic species 109 109 (main, Ag, D and Ag/D). The molecule was found to be highly bent. Okabayashi T, Yamamoto T, Mizuguchi D, Okabayashi EY, Tanimoto M (2012) Microwave spectroscopy of silver hydrosulfide AgSH. Chem Phys Lett 551:26-30

8

Silver (1+)ion – dihydrogen (1/1)

2 Inorganic Molecules without Carbon Atoms

37

CAS RN: MGD RN: 216264 IR

AgH2 C2v H

Distance Rcm b

r0 [Å] 2.02

+

Ag

a

H

Reprinted with permission. Copyright 2011 American Chemical Society. a b

Uncertainty was not given in the original paper. Distance between Ag+ and midpoint of H–H.

The rotationally resolved IR spectrum of the binary complex of the silver ion with dihydrogen was recorded in the H–H stretching region at 3750 cm-1 by detecting the Ag+ photofragments. The partial r0 structure was determined under the assumption that the H–H distance was not changed upon complexation. The complex was found to have a T-shaped structure. Dryza V, Bieske EJ (2011) Infrared spectroscopy of the Ag+-H2 complex: Exploring the connection between vibrational band-shifts and binding energies. J Phys Chem Lett 2(7):719-724

9 CAS RN: MGD RN: 549396 MW supported by ab initio calculations

Silver iodide – water (1/1) AgH2IO C2v Ag

O H

H

a

Distances Ag–I Ag…O

r0 [Å] 2.536(3) 2.227(7)

Angle

θ0 [deg] a

ϕb

I

36.3(12)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit. Angle between Ag…O and the symmetry axis of the water subunit.

The rotational spectra of the binary complex of silver iodide with water were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species; the structural parameters of the water subunit were assumed to be unchanged upon complexation. Medcraft C, Gougoula E, Bittner DM, Mullaney JC, Blanco S, Tew DP, Walker NR, Legon AC (2017) Molecular geometries and other properties of H2O⋅⋅⋅AgI and H3N⋅⋅⋅AgI as characterized by rotational spectroscopy and ab initio calculations. J Chem Phys 147(23):234308/1-234308/8 https://doi.org/10.1063/1.5008744 10 CAS RN: MGD RN: 333978 MW supported by

Silver iodide – hydrogen sulfide (1/1) AgH2IS Cs

38

2 Inorganic Molecules without Carbon Atoms

ab initio calculations

Ag

I

S H

H

a

Distances Ag…S Ag–I S–H

r0 [Å] 2.4228(18) 2.5416(9) 1.3446 b

Angle Ag…S–H

θ0 [deg] a

92.49(81)

Copyright 2012 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed at the r0 value of H2S.

The rotational spectrum of the binary complex was recorded in a laser-ablation pulsed-jet FTMW spectrometer in the frequency range between 7 and 18.5 GHz. The r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 109Ag, D, D2, 109Ag/D and 109Ag/D2). Riaz SZ, Stephens SL, Mizukami W, Tew DP, Walker NR, Legon AC (2012) H2S⋅⋅⋅Ag–I synthesized by a laserablation method and identified by its rotational spectrum. Chem Phys Lett 531:1-5 MW supported by ab initio calculations

Distances Ag–I Ag…S

r0 [Å] a 2.5484(94) 2.409(18)

Angle

θ0 [deg] a

φ

b

Cs

78.43(76)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit. Angle between Ag…S and the C2 axis of the H2S subunit.

The rotational spectra of the binary complex of silver iodide with hydrogen sulfide were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The complex was produced by a gas phase reaction of laser-ablated silver with trifluoroiodomethane and hydrogen sulfide. The partial effective structure r0 was determined from the ground-state rotational constants of six isotopic species (main, 109Ag, D, D2, 109Ag/D and 109Ag/D2) under the assumption that the structural parameters of the hydrogen sulfide subunit were not changed upon complexation. Medcraft C, Bittner DM, Tew DP, Walker NR, Legon AC (2016) Geometries of H2S⋅⋅⋅MI (M = Cu, Ag, Au) complexes studied by rotational spectroscopy: The effect of the metal atom. J Chem Phys 145(19):194306/1194306/10 [http://dx.doi.org/10.1063/1.4967477]

2 Inorganic Molecules without Carbon Atoms

11 CAS RN: 93284-76-5 MGD RN: 478020 MW supported by ab initio calculations

39

Silver iodide – ammonia (1/1) AgH3IN C3v Ag

Distances Ag–I Ag…N

r0 [Å] a 2.5375(3) 2.180(1)

rs [Å] a

Angle Ag–N–H

θ0 [deg] a

θs [deg] a

110.86(5)

I

N H

H H

2.182(1)

110.93(3)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the binary complex of silver iodide with ammonia were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The r0 partial structure was determined from the ground-state rotational constants of eight isotopic species; the structural parameters of the ammonia subunit were assumed to be unchanged upon complexation. Medcraft C, Gougoula E, Bittner DM, Mullaney JC, Blanco S, Tew DP, Walker NR, Legon AC (2017) Molecular geometries and other properties of H2O⋅⋅⋅AgI and H3N⋅⋅⋅AgI as characterized by rotational spectroscopy and ab initio calculations. J Chem Phys 147(23):234308/1-234308/8 https://doi.org/10.1063/1.5008744

12 CAS RN: 665007-72-7 MGD RN: 342860 MW supported by ab initio calculations

Silver iodide – phosphine (1/1) AgH3IP C3v Ag a

Distances P…Ag Ag–I P–H

r0 [Å] 2.3488(20) 2.5483(1) 1.4086 b

Angle H–P–H

θ0 [deg]

I

P H

H H

118.92 b

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed.

The rotational spectrum of the binary complex of silver iodide with phosphine was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz.

40

2 Inorganic Molecules without Carbon Atoms

The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 109Ag) under the assumption that the remaining structural parameters were not changed upon complexation. Stephens SL, Tew DP, Walker NR, Legon AC (2016) H3P⋅⋅⋅AgI: generation by laser-ablation and characterization by rotational spectroscopy and ab initio calculations. Phys Chem Chem Phys 18(28):1897118977

13 CAS RN: 7727-15-3 MGD RN: 387274 GED supported by MS and augmented by QC computations Bond Al–Br

rg [Å] a 2.229(5)

Aluminum tribromide AlBr3 D3h

r eM [Å] a,b 2.216(8)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ and a systematic error of 0.002r. b Anharmonic vibrational correction to the experimental bond length was estimated using computed Morse constant. Experimental data from Ref. [b] (Tnozzle = 830 K) were reanalyzed. At the temperature of the experiment, the title compound appears in monomeric form, whereas it evaporates as dimer at lower temperature. The computed bond length of the CCSD(T)/cc-pwCVQZ(PP) quality (re(Al–Br) = 2.214 Å) agrees well with equilibrium bond length derived from the experimental data. a. Varga Z, Kolonits M, Hargittai M (2012) Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation. Struct Chem 23 (3):879-893 b. Hargittai M, Kolonits M, Gödörházy L (1996) Molecular geometry of monomeric and dimeric aluminium tribromide from gas phase electron diffraction. Chem Phys Lett 257:321-326.

14 CAS RN: 7746-70-0 MGD RN: 562634 GED supported by MS and augmented by QC computations Bond Al–Cl

rg [Å] a 2.073(4)

Aluminum trichloride AlCl3 D3h

r eM [Å] a,b 2.061(5)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ and a systematic error of 0.002r. b Anharmonic vibrational correction to the experimental bond length was estimated using computed Morse constant.

2 Inorganic Molecules without Carbon Atoms

41

The GED experiment was carried out at Tnozzle = 930 K. At the temperature of the experiment, the title compound appears in monomeric form, whereas it evaporates as dimer at lower temperature. The equilibrium bond lengths derived from the experimental data and computed at the CCSD(T)/ccpwCVQZ(PP) level of theory (re(Al–Cl) = 2.060 Å) are in excellent agreement. Varga Z, Kolonits M, Hargittai M (2012) Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation. Struct Chem 23 (3):879-893

15 CAS RN: 7784-18-1 MGD RN: 571004 GED supported by MS and augmented by QC computations

Bond Al–F

rg [Å] a 1.632(3)

Aluminum trifluoride AlF3 D3h

r eM [Å] a,b 1.621(4)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ and a systematic error of 0.002r. b Anharmonic vibrational correction to the experimental bond length was estimated using computed Morse constant. Experimental data from Ref. [b] (Tnozzle =1300 K) were reanalyzed. It was revealed that aluminum trifluoride being the most ionic substance among other trihalides AlX3 (X = Cl, Br, I) sublimates at high temperatures in monomeric form. The equilibrium bond lengths estimated from experimental data and computed at the CCSD(T)/cc-pwCVQZ(PP) level of theory (re(Al–F) = 1.622 Å) are in excellent agreement. a. Varga Z, Kolonits M, Hargittai M (2012) Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation. Struct Chem 23 (3):879-893 b. Hargittai M, Kolonits M, Tremmel J, Fourquet J-L, Ferey G (1990) The molecular geometry of iron trifluoride from electron diffraction and a reinvestigation of aluminum trifluoride. Struct Chem 1:75-78

16 CAS RN: 7784-23-8 MGD RN: 598735 GED supported by MS and augmented by QC computations Bond Al–I

rg [Å] a 2.447(5)

r eM [Å] a,b 2.435(11)

Reproduced with permission of SNCSC [a].

Aluminum triiodide AlI3 D3h

42

2 Inorganic Molecules without Carbon Atoms

a

Parenthesized uncertainty in units of the last digit is estimated total error including 1.4σ and a systematic error of 0.002r. b Anharmonic vibrational correction to the experimental bond length was estimated using computed Morse constant. Experimental data from Ref. [b] (Tnozzle = 700 K) were reanalyzed. At the temperature of the experiment, the title compound appears in monomeric form, whereas it evaporates as dimer at lower temperature. The computed bond length of CCSD(T)/cc-pwCVQZ(PP) quality (re(Al–I) = 2.438 Å) agrees well with equilibrium bond length derived from the experimental data. a. Varga Z, Kolonits M, Hargittai M (2012) Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation. Struct Chem 23 (3):879-893 b. Hargittai M, Réffy B, Kolonits M (2006) An intricate molecule: Aluminum triiodide. Molecular structure of AlI3 and Al2I6 from electron diffraction and computation. J Phys Chem A 110:3770-3777

Di-µ-bromotetrabromodialuminum Aluminum tribromide dimer Al2Br6 D2h (see comment)

17 CAS RN: 18898-34-5 MGD RN: 336201 GED supported by MS and augmented by QC computations

Br

Bonds Al–Br(t) Al–Br(b)

rg [Å] a 2.228(5) 2.423(8)

Bond angles Br(t)–Al–Br(t) Br(b)–Al–Br(b)

θa [Å] a

Dihedral and other angles

τa [Å] a

ϕ

c

tilt d

r eM [Å] a,b 2.222(6) 2.410(9)

Br

Br Al

Al Br

Br Br

121.7(11) 92.9(3)

161.4(16) 0.2(25)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ, a systematic error of 0.002r and variation of the parameters upon reasonable changes of the constrained parameters. b Anharmonic vibrational corrections to the experimental internuclear distances were estimated using computed Morse constant for the monomeric molecule. c Puckering angle between the Br(b)–Al–Br(b) planes. d Tilt angle of the Br(t)–Al–Br(t) unit. Experimental data from Ref. [b] (Tnozzle = 360 K) were reanalyzed. At the temperature of the experiment, aluminum tribromide evaporates as dimer, whereas it appears as monomer at higher temperature only. According to predictions of MP2 and PBE0 computations (with cc-pwCVTZ(PP) basis set), the molecule has D2h symmetry, whereas averaged experimental structure has C2v symmetry.

2 Inorganic Molecules without Carbon Atoms

43

a. Varga Z, Kolonits M, Hargittai M (2012) Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation. Struct Chem 23 (3):879-893 b. Hargittai M, Kolonits M, Gödörházy L (1996) Molecular geometry of monomeric and dimeric aluminium tribromide from gas phase electron diffraction. Chem Phys Lett 257:321-326.

Di-µ-chlorotetrachlorodialuminum Aluminum trichloride dimer Al2Cl6 D2h (see comment)

18 CAS RN: 13845-12-0 MGD RN: 229733 GED supported by MS and augmented by QC computations

Cl

Bonds Al–Cl(t) Al–Cl(b)

rg [Å] a 2.071(4) 2.267(7)

Bond angles Cl(t)–Al–Cl(t) Cl(b)–Al–Cl(b)

θa [Å] a

r eM [Å] a,b 2.065(5) 2.254(8)

Cl

Cl Al

Al Cl

Cl

Cl

123.6(12) 91.5(9)

Dihedral and other angles τa [Å] a 164.8(31) ϕc tilt d 1.4(33) Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ, a systematic error of 0.002r and variation of the parameters upon reasonable changes of the constrained parameters. b Anharmonic vibrational corrections were estimated using computed Morse constant for the monomeric molecule. c Puckering angle between the Cl(b)–Al–Cl(b) planes. d Tilt angle of the Cl(t)–Al–Cl(t) unit. At Tnozzle = 410(10) K, aluminum trichloride evaporates in dimeric form, whereas the monomeric molecules appear at higher temperature only. According to predictions of MP2 and PBE0 computations (with cc-pwCVTZ(PP) basis set), the molecule has D2h symmetry, whereas averaged experimental structure has C2v symmetry. Varga Z, Kolonits M, Hargittai M (2012) Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation. Struct Chem 23 (3):879-893

19 CAS RN: 18898-35-6 MGD RN: 603842 GED supported by MS and augmented by QC computations

Di-µ-iodotetraiododialuminum Aluminum triiodide dimer Al2I6 D2h (see comment)

44

2 Inorganic Molecules without Carbon Atoms

Bonds Al–I(t) Al–I(b)

rg [Å] a 2.457(6) 2.670(10)

Bond angles I(t)–Al–I(t) I(b)–Al–I(b)

θa [Å] a

Dihedral and other angles

τa [Å] a

ϕ

r eM [Å] a,b 2.447(6) 2.640(11)

I

I

Al

I

I

119.3(13) 94.6(5)

c

tilt d

147.6(19) 4.7(20)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ, a systematic error of 0.002r and variation of the parameters upon reasonable changes of the constrained parameters. b Anharmonic vibrational corrections to the experimental internuclear distances were estimated using computed Morse constant for the monomeric molecule. c Puckering angle between the I(b)–Al–I(b) planes. d Tilt angle of the I(t)–Al–I(t) unit. Experimental data from Ref. [b] (Tnozzle = 435 K) were reanalyzed. At the temperature of the experiment, aluminum triiodide evaporates as dimer, whereas it appears as monomer at higher temperature only. According to predictions of PBE0 computations (with cc-pwCVTZ(PP) basis set), the molecule has D2h symmetry, whereas averaged experimental structure has C2v symmetry. a. Varga Z, Kolonits M, Hargittai M (2012) Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation. Struct Chem 23 (3):879-893 b. Hargittai M, Réffy B, Kolonits M (2006) An intricate molecule: Aluminum triiodide. Molecular structure of AlI3 and Al2I6 from electron diffraction and computation. J Phys Chem A 110:3770-3777.

20 CAS RN: 96332-57-9 MGD RN: 170896 IR

Dihydrogen – argon (1/1) ArH2 C2v H

Distance Rcm b

H

Ar

r0 [Å] a 3.957

Republished with permission of Canadian Science Publishing. Permission conveyed through Copyright Clearance Center, Inc.

a b

Uncertainty was not given in the original paper. Distance between Ar and the center-of-mass of H2.

The partial r0 structure of the title complex was redetermined from the previously published ground-state rotational constants assuming that the H–H distance was not changed upon complexation.

I

Al

I

2 Inorganic Molecules without Carbon Atoms

45

McKellar ARW (2013) High resolution infrared spectra of H2-Xe and D2-Xe van der Waals complexes. Can J Phys 91(11):957-962

21 CAS RN: 7784-34-1 MGD RN: 242165 GED augmented by ab initio computations

Bond As–Cl

rh1 [Å] a 2.164(4) b

Bond angle Cl–As–Cl

θh1 [deg] a

Arsenous trichloride AsCl3 C3v

98.9(3)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit is the estimated standard deviation. Difference to rh1(As–Cl) in dichlorovinylarsine was restrained to the value from MP2/6-311++G** computation. b

The GED experiment was carried out at the nozzle temperature of 293 K. AsCl3 was found to be a byproduct in the dichlorovinylarsine sample. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from MP2/6-31+G* computation. Noble-Eddy R, Masters SL, Rankin DWH, Robertson HE, Guillemin JC (2010) Molecular structures of vinylarsine, vinyldichloroarsine and arsine studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 978 (1-3):26-34

22 CAS RN: 82499-63-6 MGD RN: 307008 UV supported by QC calculations

Bonds H–As As=O

r0 [Å] a 1.576(3) 1.6342(5)

Bond angle H–As=O

θ0 [deg] a 101.5(4)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

Oxoarsine AsHO Cs As

H

O

46

2 Inorganic Molecules without Carbon Atoms

The rotationally resolved spectra of oxoarsine (1Aꞌ electronic ground state) were investigated by pulsed discharge jet laser spectroscopy. The laser-induced fluorescence and single vibronic level emission techniques were employed. The transient species were produced by a discharge of a mixture of arsine and carbon dioxide. The r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D). Grimminger R, Clouthier DJ (2011) The electronic spectrum of the previously unknown HAsO transient molecule. J Chem Phys 135(18):184308/1-184308/8 doi:10.1063/1.3658645

23 CAS RN: 14644-45-2 MGD RN: 458081 UV supported by ab initio calculations

Arsino AsH2 C2v As H

H

Bond As–H

r0 [Å] a 1.519(1)

rz [Å] a 1.5322(8)

re [Å] a 1.5169(8)

Bond angle H–As–H

θ0 [deg] a

θz [deg] a

θe [deg] a

90.75(9)

90.7(2)

90.7(2)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainty in units of the last significant digit.

The rotationally resolved spectra of two deuterated species of the arsino radical (2B1 electronic ground state) were recorded using laser-induced fluorescence and wavelength resolved emission techniques in the spectral region between 408 and 505 nm. The radicals were produced by a pulsed DC discharge of arsine as precursor. The r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D2). The approximate equilibrium distance re(As–H) was derived from the rz one by taking into account the anharmonic vibrational contribution estimated from the Morse constant in diatomic approximation. Grimminger RA, Clouthier DJ (2012) Toward an improved understanding of the AsH2 free radical: Laser spectroscopy, ab initio calculations, and normal coordinate analysis. J Chem Phys 137(22):224307/1-224307/12 http://dx.doi.org/10.1063/1.4769778

24 CAS RN: 1196102-14-3 MGD RN: 214351 UV supported by ab initio calculations

Arsenooxy AsH2O Cs O

As a

Bonds As–H As=O

r0 [Å] 1.513(4) 1.6720(11)

Bond angles H–As–H H–As=O

θ0 [deg] a 101.8(4) 106.6(5)

H

H

2 Inorganic Molecules without Carbon Atoms

47

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotationally resolved electronic spectra of the arsenoxy radical (2Aꞌ electronic ground state) were recorded in a supersonic jet by laser-induced fluorescence and single vibronic level emission spectroscopy in the region between 19500 and 21600 cm-1. The radical was produced in a pulsed discharge jet using arsine and carbon dioxide as precursors; the deuterated species were formed by using deuterated arsine species. The r0 structure was determined from the ground-state rotational constants of three isotopic species (main, D and D2). He SG, Sunahori FX, Yang J, Clouthier DJ (2009) Heavy atom nitroxyl radicals. II: Spectroscopic detection of H2As=O, the prototypical arsenyl free radical. J Chem Phys 131(11):114311/1-114311/7 doi:10.1063/1.3230142 25 CAS RN: 7784-42-1 MGD RN: 246569 MW supported by ab initio calculations

Arsine AsH3 C3v As

H

H H

Bond As–H

re [Å] a 1.5109

Bond angle H–As–H

θe [deg] a 92.189

Copyright 2009 with permission from Elsevier [a].

a

Uncertainty was not given in the original paper.

The equilibrium structure was determined from the experimental ground-state rotational constants and previously published experimental rotation-vibration interaction constants. a. Demaison J, Møllendal H., Guillemin JC (2009) Equilibrium CAs and CSb bond lengths. J Mol Struct 930(13):21-25 GED augmented by ab initio computations

Bond As–H Bond angle H–As–H

rh1 [Å] a 1.503(2)

θh1 [deg] a 93.2(9) b

Copyright 2009 with permission from Elsevier [b].

C3v

48 a b

2 Inorganic Molecules without Carbon Atoms

Parenthesized uncertainty in units of the last significant digit is the estimated standard deviation. Restrained to the value from MP2/6-311++G** computation.

The GED experiment was carried out at the nozzle temperature of 293 K. Vibrational correction to the experimental bond length, ∆rh1 = ra – rh1, was calculated using harmonic force constants from MP2/6-31+G* computation. b. Noble-Eddy R, Masters SL, Rankin DWH, Robertson HE, Guillemin JC (2010) Molecular structures of vinylarsine, vinyldichloroarsine and arsine studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 978 (1-3):26-34

26 CAS RN: 12511-95-4 MGD RN: 349429 GED

1,2,3-Triphospha-4-arsatricyclo[1.1.0.02,4]butane Arsenic triphosphide AsP3 C3v As

Bonds As–P P–P

rg [Å] a 2.1949(28) 2.3041(12)

P

P

P

Reprinted with permission. Copyright 2010 American Chemical Society [a].

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The GED experiment was carried out at Tnozzle = 388 K. The molecule was assumed to have C3v point-group symmetry. a. Cossairt BM, Cummins CC, Head AR, Lichtenberger DL, Berger RJF, Hayes SA, Mitzel NW, Wu G (2010) On the molecular and electronic structures of AsP3 and P4. J Am Chem Soc 132 (24):8459-8465 MW augmented by GED and supported by QC calculations

Bonds As–P P–P

C3v

r0 [Å] a 2.311 2.201

Copyright 2012 with permission from Elsevier [b].

a

Uncertainties were not given in the original paper.

The rotational spectra for three different vibrational states were recorded in a supersonic jet by an FTMW spectrometer in the spectral region between 4 and 14 GHz. The r0 structure was determined from one ground-state rotational constant; the ratio of the As–P and P–P distances was adopted from the GED structure taken from the literature.

2 Inorganic Molecules without Carbon Atoms

49

b. Daly AM, Cossairt BM, Southwood G, Carey SJ, Cummins CC, Kukolich SG (2012) Microwave spectrum of arsenic triphosphide. J Mol Spectrosc 278:68-71

27 CAS RN: 51292-90-1 MGD RN: 345338 GED augmented by QC computations

1,2-closo-Diarsadodecaborane(10) As2B10H10 C2v H B BH

a

Bonds As–As As–B B–B B–H As(1)–B(3) As(1)–B(4) B(3)–B(4) B(4)–B(9) B(9)–B(12) B(8)–B(9) B(3)–B(8) B(4)–B(5)

rh1[Å] 2.496(1) 2.198(2) b 1.817(2) b 1.210(4) b,c 2.259(5) d 2.138(4) d 1.873(12) e 1.794(5) e 1.800(5) e 1.809(5) e 1.775(9) e 1.882(21) e

Dihedral angles B(4)–As(1)–B(3)–As(2) B(3)–As(2)–As(1)–B(6)

τh1 [deg] a

As

BH HB

BH

HB

BH

As

BH HB B H

135.4(3) c -118.3(5) c

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Average value. c Restrained to the value from BP86/SDD(As),6-31G** computation. d Difference between the As–B bond lengths was restrained to the value from computation as above. e Differences between the B–B bond lengths were restrained to the values from computation as above. b

The GED experiment was carried out at Tnozzle of 493 and 498 K at the long and short nozzle-to-film distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from HF/6-31G* computation. McLellan R, Boag NM, Dodds K, Ellis D, Macgregor SA, McKay D, Masters SL, Noble-Eddy R, Platt NP, Rankin DWH, Robertson HE, Rosair GM, Welch AJ (2011) New chemistry of 1,2-closo-P2B10H10 and 1,2-closoAs2B10H10; in silico and gas electron diffraction structures, and new metalladiphospha- and metalladiarsaboranes. Dalton Trans 40 (27):7181-7192

28 CAS RN: MGD RN: 405051 MW supported by ab initio calculations

Chloro(dihydrogen-H,H)gold Gold(I) chloride – dihydrogen (1/1) AuClH2 C2v

50

Bond H–H

2 Inorganic Molecules without Carbon Atoms H

reff [Å] a,b 0.92(1)

Au

Cl

H

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainty in units of the last significant digit. See comment.

The rotational spectra of the binary complex of gold(I) chloride with dihydrogen were recorded in a supersonic jet by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 26.5 GHz. The partial effective structure reff was obtained from the determined nuclear spin-nuclear spin interaction constants Daa and Dbb. Obenchain DA, Frank DS, Grubbs GS, Pickett HM, Novick SE (2017) The covalent interaction between dihydrogen and gold: A rotational spectroscopic study of H2-AuCl. J Chem Phys 146(20):204302/1-204302/7 [http://dx.doi.org/10.1063/1.4983042]

29 CAS RN: MGD RN: 500773 MW supported by ab initio calculations

Gold(I) iodide – hydrogen sulfide (1/1) AuH2IS

Cs

Au

S H

H

a

Distances Au…S Au–I

r0 [Å] 2.256665(19) 2.5191 b

Angle

θ0 [deg] a

φc

I

71.587(13)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Assumed. c Angle between Au…S and the C2 axis of the H2S subunit. b

The rotational spectra of the binary complex of gold(I) iodide with hydrogen sulfide were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The complex was produced by a gas phase reaction of laser-ablated gold with trifluoroiodomethane and hydrogen sulfide. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main, D and D2) under the assumption that the structural parameters of the hydrogen sulfide subunit were not changed upon complexation. Medcraft C, Bittner DM, Tew DP, Walker NR, Legon AC (2016) Geometries of H2S⋅⋅⋅MI (M = Cu, Ag, Au) complexes studied by rotational spectroscopy: The effect of the metal atom. J Chem Phys 145(19):194306/1194306/10 [http://dx.doi.org/10.1063/1.4967477]

2 Inorganic Molecules without Carbon Atoms

30 CAS RN: 51374-91-5 MGD RN: 214523 UV supported by ab initio calculations

51

Fluoroborane(2) BFH Cs B H

F

Bonds B–H B–F

r0 [Å] a 1.214(2) 1.3034(5)

Bond angle F–B–H

θ0 [deg] a 120.7(1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotationally resolved electronic spectra of fluoroborane(2) (2Aꞌ electronic ground state) were investigated in a supersonic jet by laser-induced fluorescence and single vibronic level emission spectroscopy in the region between 600 and 745 nm. The radical and its deuterated species were produced by a discharge of borane with hydrogen and deuterium, respectively. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main and D). Sunahori FX, Clouthier DJ (2009) The electronic spectrum of the fluoroborane free radical. II. Analysis of laserinduced fluorescence and single vibronic level emission spectra. J Chem Phys 130(16):164310/1-164310/10 doi: 10.1063/1.3122031

31 CAS RN: 106327-54-2 MGD RN: 948395 MW augmented by ab initio calculations

Fluorohydroxyborane BFH2O Cs (syn) H

B a

Bonds B–H B–F B–O O– H

r [Å] 1.1900(1) 1.3200(3) 1.3464(3) 0.9584(3)

Bond angles H– B – F F–B–O B – O– H

θ see [deg] a

se e

119.38(10) 117.203(5) 122.65(3)

Copyright 2014 Wiley Periodicals, Inc. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

F

OH

52

2 Inorganic Molecules without Carbon Atoms

The semiexperimental equilibrium structure of the syn conformer, characterized by the synperiplanar H–O–B–H torsional angle, was determined from the previously published ground-state rotational constants of ten isotopic species accounting for rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ quadratic and cubic force fields. Vogt N, Demaison J, Vogt J, Rudolph HD (2014) Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method: structure of molecules containing the OH or the CH3 group. J Comput Chem 35(32):2333-2342

32 CAS RN: 13842-55-2 MGD RN: 313328 UV

Difluoroborane(2) BF2 C2v B

Bond B–F

r0 [Å] a 1.3102(9)

Bond angle F–B–F

θ0 [deg] a

F

F

119.7(6)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainty in units of the last significant digit.

The rotationally resolved near ultraviolet spectra of difluoroborane(2) (2A1 electronic ground state) were recorded in a supersonic jet by detecting laser-induced fluorescence and single vibronic level emissions in the 340-286 nm region. The radicals were produced by a discharge of trifluoroborane. The effective structure r0 was determined from the ground-state rotational constants of two isotopic species (main and 10B). Yang J, Ellis B, Clouthier DJ (2011) The complex spectrum of a “simple” free radical: The A-X band system of the jet-cooled boron difluoride free radical. J Chem Phys 135(9):094305/1-094305/9 doi:10.1063/1.3624528

33 CAS RN: 13867-66-8 MGD RN: 139475 IR augmented by ab initio calculations

Bonds B–F(1) B–F(2) B–O O– H

r see [Å] a 1.3239(2) 1.3139(2) 1.3426(3) 0.9581(6)

Bond angles O–B–F(1)

θ see [deg] a 122.31(2)

Difluorohydroxyborane Difluoroborinic acid BF2HO Cs OH B

F

F

2 Inorganic Molecules without Carbon Atoms

B – O– H O–B–F(2) F–B–F

53

113.09(4) 119.47(2) 118.22(3)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotationally resolved FTIR spectrum of 11BF2OH was recorded in the region of the ν1, ν2 and ν3 fundamental bands between 1300 and 3730 cm-1. Moreover the first excited states of the ν6, ν7, ν8 and ν9 were reanalyzed. The semiexperimental equilibrium structure r see was determined taking into account rovibrational corrections calculated with the CCSD(T)_ae/TZ2Pf harmonic and anharmonic (cubic) force fields. Vogt N, Demaison J, Rudolph HD, Perrin A (2015) Interplay of experiment and theory: high resolution infrared spectrum and accurate equilibrium structure of BF2OH. Phys Chem Chem Phys 17(45):30440-30449

34 CAS RN: 14452-64-3 MGD RN: 138061 UV supported by ab initio calculations

Borane(2) BH2 C2v B

Bond B–H

r0 [Å] a 1.197(2)

Bond angle H– B – H

θ0 [deg] a

H

H

129.6(2)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainty in units of the last significant digit is 1σ value.

The rotationally resolved electronic spectrum of borane(2) (2A1 electronic ground state) was recorded in a supersonic jet by laser-induced fluorescence technique. The radicals were produced by an electric discharge of diborane(6). The r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D2). Sunahori FX, Gharaibeh M, Clouthier DJ, Tarroni R (2015) BH2 revisited: New, extensive measurements of laser-induced fluorescence transitions and ab initio calculations of near-spectroscopic accuracy. J Chem Phys 142(17):174302/1-174302/13 [http://dx.doi.org/10.1063/1.4919094]

35 CAS RN: 13780-71-7 MGD RN: 496859 MW augmented by ab initio calculations

Boronic acid Dihydroxyborane BH3O2 Cs (syn-anti)

54

2 Inorganic Molecules without Carbon Atoms

Bonds B–H B–O(2) O(2)–H B–O(1) O(1)–H

r see [Å] a 1.1887(9) 1.3548(2) 0.9608(2) 1.3634(1) 0.9568(3)

Bond angles H–B–O(2) B–O(2)–H H–B–O(1) B–O(1)–H

θ see [deg] a

OH

H

B OH

118.52(7) 111.917(8) 122.35(7) 112.88(3)

Copyright 2014 Wiley Periodicals, Inc. Reproduced with permission. a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure of the syn-anti conformer, characterized by the synperiplanar HO(1)–B–H and antiperiplanar H–B–O(2)–H torsional angles, was determined from the previously published ground-state rotational constants of 18 isotopic species accounting for rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Vogt N, Demaison J, Vogt J, Rudolph HD (2014) Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method: structure of molecules containing the OH or the CH3 group. J Comput Chem 35(32):2333-2342

36 CAS RN: 13774-81-7 MGD RN: 314779 MW augmented by QC calculations

Ammonia – borane (1/1) BH6N C3v H

H

H

Distances B…N B–H N– H

r (1) [Å] a m 1.6576(16) 1.2098(2) 1.0083(3)

Angles N…B–H B…N–H

θ (1) [deg] a m 104.73(1) 110.29(2)

r see [Å] a 1.6453(1) 1.2058(3) 1.0101(3)

N H

B H H

θ see [deg] a 105.00(2) 110.97(2)

Reprinted with permission. Copyright 2008 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

was determined from the previously published ground-state rotational The mass-dependent structure r (1) m constants of nine isotopic species (main, 10B, 15N, two D2, two D3, 10B/15N and 10B/D3). The semiexperimental equilibrium structure r see was obtained taking into account the rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)_ae/cc-PVTZ quadratic and cubic force fields. The effective barrier to internal rotation was redetermined to be V3 = 718(17) cm-1.

2 Inorganic Molecules without Carbon Atoms

55

Demaison J, Lievin J, Császár AG, Gutle C (2008) Equilibrium structure and torsional barrier of BH3NH3. J Phys Chem A 112(19):4477-4482

37 CAS RN: 19287-45-7 MGD RN: 405850 GED augmented by ab initio computations

Diborane(6)

H

H B

Bonds B–H(b) b B–H(t) b Bond angles B–H(b)–B b H(t)–B–H(t) b

ra3,1 [Å] a 1.329(10) c 1.188(11) c

B 2H 6 D2h H B

H

H

H

θa3,1 [deg] a 94.0(9) c 122.4(11) c

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. H(b) and H(t) are bridging and terminal H atoms, respectively. c Restrained to the value from MP2_full/aug-cc-pVQZ computation. b

The GED experiment was carried out at Tnozzle ≈ 382 K. The trihydro(methanamine)boron sample was found to be dissociated. The best fit to the experimental intensities was obtained by accounting for two dissociation products, methylamine (CH3NH2) and diborane (B2H6). The fraction of the non-dissociated trihydro(methanamine)boron was determined to be 0.67(3). For the title molecule, vibrational corrections to the experimental internuclear distances, ∆ra3,1 = ra − ra3,1, were calculated from the HF/6-31G* quadratic and cubic force constants taking into account non-linear kinematic effects. Aldridge S, Downs AJ, Tang CY, Parsons S, Clarke MC, Johnstone RDL, Robertson HE, Rankin DWH, Wann DA (2009) Structures and aggregation of the methylamine-borane molecules, MenH3-nN·BH3 (n=1-3), studied by X-ray diffraction, gas-phase electron diffraction, and quantum chemical calculations. J Am Chem Soc 131 (6):2231-2243

38 CAS RN: 63115-77-5 MGD RN: 514661 GED augmented by QC computations

Bonds B(2)–B(3) B(3)–B(7) B(3)–B(8) B(1)–B(2) B(2)–S(6)

6,8-Dithianonaborane(9) B7H9S2 Cs

H

rh1 [Å] a 1.794(4) b 1.791(5) b 1.727(8) b 1.748(17) b 1.946(9) b

HB S

H

H B

BH

HB HB

BH

B H

S

56

2 Inorganic Molecules without Carbon Atoms

B(2)–B(7) B(2)–B(5) B(5)–S(6) S(6)–B(7) B(7)–B(8) B–H c B(8)–Hʹ B(8)–Hʹʹ B(7)–Hʹʹ

1.897(12) b 1.830(7) b 1.908(11) b 1.907(14) b 1.798(10) b 1.253(3) d 1.204(3) e 1.192(13) e 1.428(9) e

Angles B(1)–B(2)–B(7) B(1)–B(2)–S(6) B(7)–B(2)–S(6) Y…X…B(5) f

θh1 [deg] a

Dihedral angle B(1)–B(2)–B(7)–Hʹʹ

τh1 [deg] a

107.2(4) d 114.4(2) d 63.7(6) d 94.5(7) d

33.0(11) d,g

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Figures in parentheses are the estimated standard deviations of the last digits. Differences between the B–B and B–S bond lengths were flexibly restrained to the values derived from the MP2_full/6-311++G(3df,3pd) structure. c Averaged. d Independent parameter. e Differences between the B–H bond lengths were flexibly restrained to the values from computation as indicated above. f X refers to the midpoint of B(1)–B(2), Y refers to the midpoint of B(7)...B(9). g Flexibly restrained to the value from computation as above. b

The GED experiment was carried out at Tnozzle of 388 and 403 K at the long and short nozzle-to-film distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311+G(d,p) computation. Wann DA, Lane PD, Robertson HE, Holub J, Hnyk D (2013) Structures of, and related consequences of deprotonation on, two Cs-symmetric arachno nine-vertex heteroboranes, 4,6-X2B7H9 (X = CH2; S) studied by gas electron diffraction/quantum chemical calculations and GIAO/NMR. Inorg Chem 52 (8):4502-4508

39 CAS RN: 41646-56-4 MGD RN: 146061 GED augmented by QC computations

Bonds S–B B–B B–H B(2)–B(3) B(2)–B(6)

rh1[Å] a 1.9386(14) 1.8214(8) b 1.213(3) b 1.9450(15) c 1.790(2) c

1-Thia-closo-decaborane(9)

H

S

H H H

B B

H

B

B

B B

B

B

H B H

B9H9S C4v

H H

2 Inorganic Molecules without Carbon Atoms

B(6)–B(7) B(6)–B(10)

1.857(3) c 1.726(3) c

Bond angles S–B(2)–H B(10)–B(8)–H

θh1 [deg] a

57

110.7(9) d 119.3(8) d

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. b Average value. c Differences between the B–B bond lengths were restrained to the values from MP2_full/6-311++G** computation. d Restrained to the value from computation as above. The GED experiment was carried out at the nozzle temperature between 338 and 346 K. Assuming C4v symmetry, the cage structure was found to be distorted from a symmetrically bicapped square antiprism. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/aug-cc-pVTZ computation. Hnyk D, Wann DA, Holub J, Samdal S, Rankin DWH (2011) Why is the antipodal effect in closo-1-SB9H9 so large? A possible explanation based on the geometry from the concerted use of gas electron diffraction and computational methods. Dalton Trans 40 (21):5734-5737

40 CAS RN: 119593-19-0 MGD RN: 345500 GED augmented by ab initio computations

1,2-closo-Diphosphadodecaborane(10) B10H10P2 C2v H B BH P

Bonds P–P P–B B–B B–H P(1)–B(4) B(4)–B(9) B(3)–B(8) B(9)–B(12) B(4)–B(5) (4)–B(8) B(8)–B(9)

rh1[Å] a 2.310(2) 2.055(1) b,c 1.796(1) b 1.201(2) b 2.018(2) 1.785(2) d 1.770(2) d 1.785(4) d 1.835(6) d 1.776(10) d 1.796(3) d

Dihedral angles B(4)–P(1)–B(3)–P(2) B(3)–P(2)–P(1)–B(6)

τh1 [deg] a

BH HB

BH

HB

BH

P

BH HB B H

137.2(1) -120.9 e

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations.

58

2 Inorganic Molecules without Carbon Atoms

b

Average value. Restrained to the value from MP2/6-31G** computation. d Differences between the B–B bond lengths were restrained to the values from computation as above. e Adopted from computation as indicated above. c

The GED experiment was carried out at Tnozzle of 473 and 488 K at the short and long nozzle-to-film distances. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from HF/6-31G* computation. McLellan R, Boag NM, Dodds K, Ellis D, Macgregor SA, McKay D, Masters SL, Noble-Eddy R, Platt NP, Rankin DWH, Robertson HE, Rosair GM, Welch AJ (2011) New chemistry of 1,2-closo-P2B10H10 and 1,2-closoAs2B10H10; in silico and gas electron diffraction structures, and new metalladiphospha- and metalladiarsaboranes. Dalton Trans 40 (27):7181-7192

41 CAS RN: 7787-53-3 MGD RN: 378308 GED combined with MS

Bond Be–I Bond angle I–Be–I

Beryllium diiodide BeI2 D∞ h

rg [Å] a T = 501(5) K T = 722(10) K 2.163(6) 2.172(7)

θg [deg] a

T = 501(5) K 165(3)

T = 722(10) K 162(4)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are 2.5σ values.

The thermal-average structure of the title molecule was determined at two temperatures. The equilibrium structure was estimated to be linear accounting for shrinkage effect. The equilibrium bond length re(Be–I) was roughly estimated in diatomic approximation according to equation: re = rg – 3/2(a3 l2) = 2.154(8) Å, where a3 is Morse constant and l is root-mean-square vibrational amplitude. Shlykov SA, Zhabanov YA, Giricheva NI, Girichev AG, Girichev GV (2015) Combined gas electron diffraction/mass spectrometric study of beryllium diiodide assisted by quantum chemical calculations: structure and thermodynamics of beryllium dihalides. Struct Chem 26 (5-6):1451-1458

42 CAS RN: 190521-19-8 MGD RN: 313709 UV

Diberyllium oxide (1+)ion Be2O D∞ h Be

Bond Be–O

r0 [Å] a 1.392(8)

O

Be

2 Inorganic Molecules without Carbon Atoms

59

Reproduced with permission of AIP Publishing. a

Parenthesized uncertainty in units of the last significant digit.

The rotationally resolved ultraviolett spectrum of diberyllium oxide (1+)ion (2Σg+ electronic ground state) was recorded using the pulsed-field ionization zero electron kinetic energy photoelectron technique. The symmetric stretching fundamental and the first two bending levels were investigated. Antonov IO, Barker BJ, Heaven MC (2011) Pulsed-field ionization zero electron kinetic energy spectrum of the ground electronic state of BeOBe+. J Chem Phys 134(4):044306/1-044306/4 doi:10.1063/1.3541255

43 CAS RN: 37981-39-8 MGD RN: 137088 MW supported by DFT calculations

Bromogermylene BrGeH Cs Ge

H

Br

Bonds Ge–Br Ge–H

r0 [Å] a 2.3276(9) 1.6093(7)

r (1) [Å] a m 2.3243(2) 1.563(9)

Bond angle H–Ge–Br

θ0 [deg] a

θ (1) [deg] a m

92.44(4)

93.55(24)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of bromogermylene were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 5 and 25 GHz. Eight BrGeH isotopic species and nine BrGeD species (with 70Ge, 72Ge, 74Ge, 76Ge, 79Br and 81Br) were measured in natural abundance. The transient species were produced by a pulsed electrical discharge of bromogermane. structures were determined from the ground-state rotational constants of The r0 and mass-dependent r (1) m seventeen isotopic species. Kang L, Sunahori F, Minei AJ, Clouthier DJ, Novick SE (2009) Fourier transform microwave spectroscopy of monobromogermylene (HGeBr and DGeBr), a heavy atom carbene analog. J Chem Phys 130(12):124317/1124317/11 doi: 10.1063/1.3080161

44 CAS RN: 13517-11-8 MGD RN: 623091 MW, IR

Hypobromous acid

O H

Bonds

re [Å]

a,b

BrHO Cs Br

60

2 Inorganic Molecules without Carbon Atoms

H– O O–Br

0.9640(3) 1.82800(1)

Bond angle H–O–Br

θe [deg] a,b 102.99(1)

Copyright 2010 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. See text for the structure type definition.

The rotationally resolved vibrational spectra of DOBr were recorded by an FTIR spectrometer in the mid-IR region at 2668 and 852 cm-1. The fundamental bands ν1 and ν2 as well as the combination band ν2+3ν3 were analyzed. In addition, the rotational spectra were studied in the submillimeter-wave and THz regions. The structure was determined by fitting the near equilibrium rotational constants of the DOBr and previously studied HOBr species, which were derived from the ground state and first excited state each of the fundamentals. Cohen EA, Müller HSP, Tan TL, McRae GA (2010) High resolution spectroscopy of DOBr and molecular properties of hypobromous acid. J Mol Spectrosc 262(1):30-36

45 CAS RN: 7789-46-0 MGD RN: 608794 GED supported by MS and augmented by QC computations

Distances Fe–Br Br…Br

rg [Å] a 2.289(8) c 4.476(12)

Bond angle Br–Fe–Br

θa [deg] a

Iron(II) bromide Iron dibromide Br2Fe D∞h (see comment) FeBr2

r eM [Å] a,b 2.276(10)

155.9(29)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including random and systematic errors. b Estimated from the thermal-average bond length by taking into account Morse-like anharmonic correction and the effect of centrifugal distortion. c Difference to the terminal Fe–Br bond length in the dimeric molecule was kept at the computed value. The GED data from Ref. [b] (Tnozzle = 980 K) were reanalyzed using results of new comprehensive computations up to CCSD(T) level of theory. Both monomeric (85(1)%) and dimeric species of the title compound were detected in the vapor. Although the thermal-average structure of the monomer is non-linear (C2v symmetry), the equilibrium structure is linear (D∞h) in the gound electronic state (5Δg) as predicted by computations. a. Varga Z, Kolonits M, Hargittai M (2011) Iron dihalides: Structures and thermodynamic properties from computation and an electron diffraction study of iron diiodide. Struct Chem 22 (2):327-336

2 Inorganic Molecules without Carbon Atoms

61

b. Hargittai M, Subbotina NY, Kolonits M, Gershikov AG (1991) Molecular structure of first-row transition metal dihalides from combined electron diffraction and vibrational spectroscopic analysis. J Chem Phys 94: 7278-7286.

46 CAS RN: 12431-56-0 MGD RN: 155125 GED combined with MW and augmented by ab initio computations

Bond Na–Br

re [Å] a 2.679(3)

Bond angle Br–Na–Br

θe [deg] a

Di-µ-bromodisodium Sodium bromide dimer Br2Na2 D2h

103.8(3)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit is the estimated standard deviation.

Both monomeric and dimeric molecules of sodium bromide were detected in the gas phase at Tnozzle = 920 K. The proportion of NaBr units existing as dimer was determined to be 0.32(2). Anharmonic vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using PES from MP2_full/6-311+G(d) computation. The determined structure was found to be close to that calculated at the CCSD(T)/aug-cc-pwCVQZ level of theory. Wann DA, Rankin DWH, McCaffrey PD, Martin JML, Mawhorter RJ (2014) Equilibrium gas-phase structures of sodium fluoride, bromide, and iodide monomers and dimers. J Phys Chem A 118 (10):1927-1935

47 CAS RN: 14456-48-5 MGD RN: 156110 GED augmented by ab initio computations Bond Dy−Br

rg [Å] a 2.606(8)

Bond angle Br−Dy−Br

θa [deg] a

Dysprosium(III) bromide Dysprosium tribromide Br3Dy D3h (see comment) DyBr3 r eM [Å] a 2.591(8)

115.6(21)

Reprinted with permission. Copyright 2009 American Chemical Society [a].

a

Parenthesized uncertainty in units of the last significant digit is estimated total error including 1.4σ, a systematic error of 0.002r and the effect of constraints used in the refinement.

Previously published molecular structure of the title molecule [b] was reinvestigated.

62

2 Inorganic Molecules without Carbon Atoms

The GED experiment was carried out at 1170(50) K. The vapor of the title compound was found to exist as a mixture of 83(4) % monomeric and 17(3) % dimeric molecules. According to predictions of CASSCF, CASPT2 and MRCI+Q computations (with aug-cc-pVTZ-PP basis set for Br and small core Stuttgart ECP with associated valence basis set for Dy), the monomeric molecule has D3h symmetry in its electronic ground state. The thermal-averaged structure was found to have C3v symmetry. The deviation from planarity was completely ascribed to shrinkage effect. Vibrational correction to the experimental internuclear distance, ∆r eM = ra – r eM , was estimated using Morse constant. a. Groen CP, Varga Z, Kolonits M, Peterson KA, Hargittai M (2009) Does the 4f electron configuration affect molecular geometries? A joint computational, vibrational spectroscopic, and electron diffraction study of dysprosium tribromide. Inorg Chem 48 (9):4143-4153 b. Giricheva NI, Shlykov SA, Chernova EV, Levina YS, Krasnov AV (2005) Molecular structure of SmBr3 and DyBr3 according to the data of simultaneous electron diffraction and mass-spectrometric experiment. J Struct Chem (Engl Transl)/Zh Strukt Khim 46/46(6/6):991-997/1031-1037

48 CAS RN: 14456-53-2 MGD RN: 482007 GED combined with MS and augmented by DFT computations

Bond Lu–Br

rg [Å] a 2.553(5)

Bond angle Br–Lu–Br

θg [deg] a

Lutetium(III) bromide Lutetium tribromide Br3Lu D3h (see comment) LuBr3

115.3(10)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainty is estimated total error in units of the last significant digit.

Molecular structure from Ref. [b] was reinvestigated. The combined GED/MS experiment was carried out at Teffusion cell = 1161(10) K. The sample molecules were found to exist mainly in a monomeric form. A small amount of dimeric molecules (less than 3 mol %) was also detected. The non-planarity of the thermal-average configuration was completely ascribed to shrinkage effect. Thus, the equilibrium configuration was estimated to be planar. a. Giricheva NI, Shlykov SA, Girichev GV, Chernova EV, Lapykina EA (2009) Molecular structure of LuBr3 according to the data of the simultaneous electron diffraction and mass spectrometric experiment. J Struct. Chem (Engl Transl/Zh Strukt Khim 50/50(2/2):228-234/243-250 b. Zasorin EZ(1988) Structure of the rare-earth element trihalide molecules from electron diffraction and spectral data. Russ J Phys Chem/ Zh Fiz Khim 62/62(4/4):441-447/883-895

49 CAS RN: 66468-24-4 MGD RN: 326244 GED supported by MS and

Di-µ-bromodibromodiiron Iron dibromide dimer Br4Fe2 D2h (see comment)

2 Inorganic Molecules without Carbon Atoms

63

augmented by QC computations

Br Fe

Br

Bonds Fe–Br(t) Fe–Br(b)

rg [Å] a 2.288(8) c,d 2.504(8) d

Bond angle Br(b)–Fe–Br(b)

θa [deg] a

Fe

Br

Br

r eM [Å] a,b 2.278(13) c,d 2.478(15) d

97(3)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including random and systematic error as well as the effects of constraints. b Estimated from the thermal-average bond length by taking into account Morse-like anharmonic correction. c Difference to the Fe–Br bond length in the monomeric molecule was adopted from computation at the level of theory as indicated below. d Difference between the Fe–Br(t) and Fe–Br(b) bond lengths was adopted from computation at the level of theory as indicated below. The experimental data from Ref. [b] (Tnozzle = 980 K) were reanalyzed using results of new computations. Both monomeric (85(1)%) and dimeric species of the title compound were detected in the vapor. According to predictions of mPW1PW91 computations, the dimeric molecule is planar (D2h point-group symmetry) in the electronic ground state (9Ag). a. Varga Z, Kolonits M, Hargittai M (2011) Iron dihalides: Structures and thermodynamic properties from computation and an electron diffraction study of iron diiodide. Struct Chem 22 (2):327-336 b. Hargittai M, Subbotina NY, Kolonits M, Gershikov AG (1991) Molecular structure of first-row transition metal dihalides from combined electron diffraction and vibrational spectroscopic analysis. J Chem Phys 94:7278-7286

50 CAS RN: 14456-53-2 MGD RN: 361720 GED augmented by ab initio computations

Di-µ-bromotetrabromodidysprosium Dysprosium tribromide dimer Br6Dy2 D2d (see comment) Br

Br Dy

Bonds Dy−Br(t) b Dy−Br(b) d

rg [Å] a 2.589(10) c 2.832(20) e

Bond angles Br(t)−Dy−Br(t) b Br(b)−Dy−Br(b) d

θa [deg] a

Br

Br Dy

Br

Br

120(17) 84(5)

Reprinted with permission. Copyright 2009 American Chemical Society.

a Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ, a systematic error of 0.002r and the effect of constraints used in the refinement. b Br(t) is terminal Br atom. c Difference to the Dy−Br bond length of monomer was constrained to ab initio value. d Br(b) is bridging Br atom.

64 e

2 Inorganic Molecules without Carbon Atoms

Difference between the Dy−Br(b) and Dy−Br(t) bond lengths was constrained to computed value.

The GED experiment was carried out at 1170(50) K. The vapor of dysprosium tribromide was found to exist as a mixture of 83(4) % monomeric and 17(3) % dimeric molecules. The C2v symmetry molecular model was adopted in the GED analysis to describe the average structure of dimeric molecule, whereas the equilibrium conformation was predicted to have D2d point-group symmetry by ab initio computations (MP2 and CASSCF). Groen CP, Varga Z, Kolonits M, Peterson KA, Hargittai M (2009) Does the 4f electron configuration affect molecular geometries? A joint computational, vibrational spectroscopic, and electron diffraction study of dysprosium tribromide. Inorg Chem 48 (9):4143-4153

51 CAS RN: 1415309-16-8 MGD RN: 215476 MW supported by ab initio calculations

Distances Cu–Cl Cu…O Angle

ϕ

b

r0 [Å] a 2.062(6) 1.914(10)

Copper(I) chloride – water (1/1) ClCuH2O Cs Cu

Cl

O H

H

rs [Å] a 2.050(5) 1.925(5)

θ0 [deg] a 40.9(13)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit. Angle between Cu…O and the C2 axis of the water subunit.

The rotational spectra of the binary complex of copper(I) chloride with water were recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 15 GHz. The transient complex was produced by expansion of H2O and CCl4 in the presence of laser-ablated Cu atoms. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 65 Cu, 37Cl, 18O, D2 and 65Cu/37Cl) under the assumption that the structural parameters of the water subunit were not changed upon complexation. Mikhailov VA, Roberts FJ, Stephens SL, Harris SJ, Tew DP, Harvey JN, Walker NR, Legon AC (2011) Monohydrates of cuprous chloride and argentous chloride: H2O⋅⋅⋅CuCl and H2O⋅⋅⋅AgCl characterized by rotational spectroscopy and ab initio calculations. J Chem Phys 134(13):134305/1-134305/12 doi:10.1063/1.3561305

52 CAS RN: 1321627-30-8 MGD RN: 213110 MW supported by ab initio calculations

Copper(I) chloride – hydrogen sulfide (1/1) ClCuH2S Cs

2 Inorganic Molecules without Carbon Atoms

Distances Cu–Cl Cu…S

r0 [Å] a 2.0633(3) 2.1531(3)

Angle

θ0 [deg] a

ϕb

65

Cu

S

Cl

H

H

74.46(2)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Angle between Cu–Cl and the C2 axis of the H2S subunit.

The rotational spectra of the binary complex of copper(I) chloride with hydrogen sulfide were recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 15 GHz. The transient complex was produced by expansion of H2S and CCl4 in the presence of laser-ablated Cu atoms. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, 65 Cu, 37Cl, D, D2, 65Cu/37Cl, 65Cu/D2 and 37Cl/D2) under the assumption that the structural parameters of the hydrogen sulfide subunit were not changed upon complexation. Walker NR, Tew DP, Harris SJ, Wheatley DE, Legon AC (2011) Characterization of H2S⋅⋅⋅CuCl and H2S⋅⋅⋅AgCl isolated in the gas phase: A rigidly pyramidal geometry at sulfur revealed by rotational spectroscopy and ab initio calculations. J. Chem. Phys. 135(1):014307/1-014307/10 doi:10.1063/1.3598927

53 CAS RN: 24274-02-0 MGD RN: 453990 MW supported by ab initio calculations

Copper(I) chloride – ammonia (1/1) ClCuH3N C3v N

Cu

Distances Cu–Cl Cu…N N– H

r0 [Å] a 2.0614(7) 1.9182(13) 1.0186 b

rs [Å] a 2.058(4) 1.918(4)

Angle H–N…Cu

θ0 [deg] a

θs [deg] a

111.40(6)

Cl

H

H H

111.5(1)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed.

The rotational spectra of the binary complex of copper(I) chloride with ammonia were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The transient complex was produced by the gas phase reaction between laser-ablated copper with tetrachloromethane and ammonia. The partial r0 and rs structures were determined from the ground-state rotational constants of six isotopic species (main, 65Cu, 37Cl, 15N, D2 and D3).

66

2 Inorganic Molecules without Carbon Atoms

Bittner DM, Zaleski DP, Stephens SL, Tew DP, Walker NR, Legon AC (2015) A monomeric complex of ammonia and cuprous chloride: H3N⋅⋅⋅CuCl isolated and characterized by rotational spectroscopy and ab initio calculations. J Chem Phys 142(14):144302/1-144302/10 [http://dx.doi.org/10.1063/1.4916391]

54 CAS RN: 804557-39-9 MGD RN: 208682 MW

Chlorohydrozinc ClHZn C∞ v H

Bonds H–Zn Zn–Cl

r0 [Å] a 1.519 2.083

rs [Å] a 1.519 2.082

Cl

Zn

r (m2) [Å] b 1.5050(17) 2.08293(21)

Copyright 2009 with permission from Elsevier.

a b

Uncertainties were not given in the original paper. Parenthesized uncertainties in units of the last significant digit are 3σ values.

The rotational spectrum of chlorohydrozinc (1Σ+ electronic ground state) was recorded by an FTMW spectrometer in the spectral range between 9 and 39 GHz and by a submillimeter-wave spectrometer in the spectral range between 439 and 540 GHz. The transient species was produced by DC glow discharge of zinc vapor and chlorine gas with hydrogen or by a discharge of chlorine and dimethylzinc. The r0, rs and r (m2) structures were determined from the ground-state rotational constants of seven isotopic species (main, D, 66Zn, 67Zn, 68Zn, 37Cl and 66Zn/37Cl). Pulliam RL, Sun M, Flory MA, Ziurys LM (2009) The sub-millimeter and Fourier transform microwave spectrum of HZnCl (X1Σ+). J Mol Spectrosc 257(2):128-132

55 CAS RN: 66650-11-1 MGD RN: 125110 MW supported by ab initio calculations

Distances Na–Cl O…Na

r0 [Å] a 2.453(18) 2.233(15)

Angles O…Na–Cl Na…O–H(a)

θ0 [deg] a

79.90(60) 89.3(36)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

Sodium chloride – water (1/1) ClH2NaO Cs Na

Cl

O H

H

2 Inorganic Molecules without Carbon Atoms

67

The rotational spectra of the binary complex of sodium chloride with water were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 25 GHz. The sodium chloride was vaporized by laser ablation. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 37 Cl and two D); the remaining structural parameters were fixed to those of the free water molecule. Mizoguchi A, Ohshima Y, Endo Y (2011) The study for the incipient solvation process of NaCl in water: The observation of the NaCl-(H2O)n (n=1, 2, and 3) complexes using Fourier-transform microwave spectroscopy. J Chem Phys 135(6):064307/1-064307/11 doi:10.1063/1.36160479

56 CAS RN: 13465-78-6 MGD RN: 190190 MW augmented by ab initio calculations

Chlorosilane Silyl chloride ClH3Si C3v H

H

Si

Bonds Si–Cl Si–H Bond angle Cl–Si–H

H

a

r [Å] 2.04584(6) 1.46878(16) se e

Cl

θ see [deg] a

108.427(13)

Reprinted by permission of Taylor & Francis Ltd. Final version received 21 March 2012

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

The rotational spectra of SiH3Cl and 29SiH3Cl were recorded by millimeter-wave spectroscopy with sub-Doppler resolution in the region between 80 and 375 GHz using the Lamp-dip technique. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants accounting for the rovibrational corrections calculated with the CCSD(T)/cc-pVTZ quadratic and cubic force fields. Cazzoli G, Puzzarini C, Gauss J (2012) Rotational spectrum of silyl chloride: hyperfine structure and equilibrium geometry. Mol Phys 110(19-20):2359-2369

57 CAS RN: 23724-87-0 MGD RN: 139820 MW supported by ab initio calculations

Sodium chloride – water (1/2) ClH4NaO2 C2v Na

Distances Na–Cl O…Na

a

r0 [Å] 2.544(41) 2.233 b

Cl

O H

H

2

68

Angles O…Na–Cl Na…O–H(a)

2 Inorganic Molecules without Carbon Atoms

θ0 [deg] a

79.90(60) 89.3(36)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. b Constrained to value in NaCl ⋅ H2O. The rotational spectra of the ternary complex of sodium chloride with water were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 25 GHz. The sodium chloride was vaporized by laser ablation. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl); the remaining structural parameters were constrained to those of the free water molecule. Mizoguchi A, Ohshima Y, Endo Y (2011) The study for the incipient solvation process of NaCl in water: The observation of the NaCl-(H2O)n (n=1, 2, and 3) complexes using Fourier-transform microwave spectroscopy. J Chem Phys 135(6):064307/1-064307/11 doi:10.1063/1.36160479

58 CAS RN: 161009-38-7 MGD RN: 139647 MW supported by ab initio calculations

Sodium chloride – water (1/3) ClH6NaO3 C3v Na

Cl

O H

H

3

a

Distances Na–Cl O…Na

r0 [Å] 2.69(15) 2.233 b

Angles O…Na–Cl Na…O–H(a)

θ0 [deg] 77.0 c 89.3 b

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainty in units of the last significant digit is 1σ value. b Constrained to the value in NaCl ⋅ H2O. c Linearly extrapolated from the corresponding values of the monomer and dimer. The rotational spectra of the quaternary complex of sodium chloride with water were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 25 GHz. The sodium chloride was vaporized by laser ablation. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl); the remaining structural parameters were constrained to those of the free water molecule.

2 Inorganic Molecules without Carbon Atoms

69

Mizoguchi A, Ohshima Y, Endo Y (2011) The study for the incipient solvation process of NaCl in water: The observation of the NaCl-(H2O)n (n=1, 2, and 3) complexes using Fourier-transform microwave spectroscopy. J Chem Phys 135(6):064307/1-064307/11 doi:10.1063/1.36160479

59 CAS RN: 166530-19-4 MGD RN: 216239 MW

Hydrogen chloride – water (2/1) Cl2H4O essentially Cs H

a

Distances Cl(1)…Cl(2) Cl(1)…O Cl(2)…O

rs [Å] 3.6948(12) 3.3905(41) 3.1261(29)

Angles Cl(1)…Cl(2)…O Cl(2)…O…Cl(1) O…Cl(1)…Cl(2)

θs [deg] a

Cl

O 2

H

H

58.91(8) 68.94(7) 52.15(6)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the ternary H-bonded complex of hydrogen chloride with water were recorded in a supersonic jet by a chirped-pulsed FTMW spectrometer in the frequency region between 6 and 18.5 GHz. The partial rs structure of the heavy-atom skeleton was determined from the ground-state rotational constants of six isotopic species (main, two 37Cl, 37Cl2, 18O and D). Kisiel Z, Lesarri A, Neill JL, Muckle MT, Pate BH (2011) Structure and properties of the (HCl)2H2O cluster observed by chirped-pulse Fourier transform microwave spectroscopy. Phys Chem Chem Phys 13(31):1391213919

60 CAS RN: 7719-09-7 MGD RN: 607379 MW augmented by ab initio calculations

Thionyl chloride Sulfinyl chloride Cl2OS Cs O S a

a

Bonds S=O S–Cl

r0 [Å] 1.434(9) 2.072(3)

r [Å] 1.4340(7) 2.0700(3)

Bond angles

θ0 [deg] a

θ see [deg] a

τ0 [deg] a

τ see [deg] a

Cl–S=O Cl–S–Cl

Dihedral angle

108.00(6) 97.08 b

se e

107.703(6) 96.929 b

Cl

Cl

70

Cl–S=O…Cl

2 Inorganic Molecules without Carbon Atoms

104.0(3)

103.58(3)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit are 3σ values. Dependent value.

The rotational spectra of thionyl chloride were recorded both by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 19 GHz and by a frequency modulated millimeter/submillimeter-wave spectrometer between 70 and 660 GHz. The semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(T+d)Z harmonic and anharmonic (cubic) force fields. Martin-Drumel MA, Roucou A, Brown GG, Thorwirth S, Pirali O, Mouret G, Hindle F, McCarthy MC, Cuisset A (2016) High resolution spectroscopy of six SOCl2 isotopologues from the microwave to the far-infrared. J Chem Phys 144(8):084305/1-084305/7 [http://dx.doi.org/10.1063/1.4942024]

61 CAS RN: 10580-52-6 MGD RN: 102469 GED combined with MS and augmented by QC computations

Bond V–Cl

rg [Å] a 2.213(21)

Bond angle Cl–V–Cl

θa [deg] a

Vanadium(II) chloride Vanadium dichloride Cl2V D∞ h VCl2

r eM [Å] a,b 2.185(23)

155(8)

Reprinted with permission. Copyright 2010 American Chemical Society [a]. a

Parenthesized uncertainty in units of the last significant digit is estimated total error including 1.4σ, systematic errors and errors due to correlation among parameters. b Estimated from rg by taking into account Morse-type anharmonic vibrational correction. Molecular structure of VCl2 from Ref. [b] was reconsidered. At the temperature of the GED experiment (Tnozzle= 1330(50) K), a solid sample of vanadium dichloride evaporated as vanadium dichloride and vanadium trichloride in the amounts of 34(8) and 66(8) %, respectively. 4

+

At the CCSD(T) level of theory, the title molecule was predicted to be unambiguously linear in the Σ g ground state with equilibrium bond length being close to the r eM value. a. Varga Z, Vest B, Schwerdtfeger P, Hargittai M (2010) Molecular geometry of vanadium dichloride and vanadium trichloride: A gas-phase electron diffraction and computational study. Inorg Chem 49 (6):2816-2821 b. Hargittai M, Dorofeeva O, Tremmel J (1985) Molecular structure of vanadium dichloride and chromium dichloride from electron diffraction. Inorg Chem 24:3963-3965.

2 Inorganic Molecules without Carbon Atoms

62 CAS RN: 10138-41-7 MGD RN: 146116 GED combined with MS and augmented by QC computations

Bond Er–Cl

rg [Å] a 2.436(5)

Bond angle Cl–Er–Cl

θg [deg] a

71

Erbium(III) chloride Erbium trichloride Cl3Er D3h (see comment) ErCl3

117.0(10)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainty is estimated total error in units of the last significant digit.

The molecular structure of the title compound [b] was reinvestigated. The combined GED/MS experiment was carried out at Teffusion cell = 1165(10) K. The molecules were found to exist mainly in a monomeric form. A small amount of dimeric molecules (2.5(5) mol %) was also detected. The non-planarity of the thermal-average configuration was completely ascribed to shrinkage effect. Thus, the equilibrium configuration was estimated to be planar. a. Giricheva NI, Shlykov SA, Girichev GV, Chernova EV, Lapykina EA (2009) Molecular structure of ErCl3 and YbCl3 according to the data of the simultaneous electron diffraction and mass spectrometric experiment. J Struct Chem (Engl Trans)/Zh Strukt Khim 50/50(2/2):235 -245/251-261 b. Giricheva NI, Girichev GV, Shlykov SA, Pelipets OV(2000) Molecular structure of erbium trichloride monomer and dimer by electron diffraction and mass spectrometric data. J Struct Chem (Engl Transl)/Zh Strukt Khim 41/41(2/2), 231-237/285-293

63 CAS RN: 7705-08-0 MGD RN: 770005 GED augmented by QC computations Bond Fe–Cl

rg [Å] a 2.136(5) b

Bond angle Cl–Fe–Cl

θa [deg] a

Iron(III) chloride Iron trichloride Cl3Fe D3h FeCl3 r eM [Å] a 2.122(6)

116.6(6)

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit is estimated total error including 1.4σ, a systematic error of 0.002r and the variation of the parameter upon reasonable changes of the constrained parameters. b According to results of mPW1PW91/ECP10MDF/cc-pVQZ-PP computations, the Fe–Cl bond length in the monomer and the terminal Fe–Cl(t) bond length in the dimeric molecule were assumed to be equal.

72

2 Inorganic Molecules without Carbon Atoms

The GED experiment was carried out at Tnozzle = 900(50) K. The title compound was found to exist as a mixture of the monomeric (79(3)%) and dimeric molecules. The anharmonic vibrational correction to the experimental thermal-average bond length, ∆r eM = rg − r eM , was estimated in the diatomic approximation using Morse constant. Varga Z, Kolonits M, Hargittai M (2010) Gas-phase structures of iron trihalides: A computational study of all iron trihalides and an electron diffraction study of iron trichloride. Inorg Chem 49 (3):1039-1045

64 CAS RN: 7718-98-1 MGD RN: 367910 GED combined with MS and augmented by QC computations Bond V–Cl

rg [Å] a 2.175(8)

Bond angle Cl–V–Cl

θa [deg] a

Vanadium(III) chloride Vanadium trichloride Cl3V (see comment) VCl3

r eM [Å] a 2.149(9) b

116.1(7) c

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit is estimated total error including 1.4σ, systematic errors and errors due to correlation among parameters. b Estimated from rg by taking into account Morse-type anharmonic correction. c Thermal-average and average for all electronic states bond angle, corresponding to planar equilibrium structure with the bond angle of 120°. At the temperature of the GED experiment (Tnozzle = 1330(50) K), a solid sample of vanadium dichloride evaporated as vanadium trichloride and vanadium dichloride in an amount of 66(8) and 34(8)%, respectively. According to QC predictions, the title molecule should be present in the high-temperature vapor both in the ground and excited electronic states, separated by very small energy differences. All computations yielded a Jahn-Teller-distorted ground-state structure of C2v symmetry. However, the small splitting of the Cl…Cl internuclear distance due to distortion of the Cl–V–Cl bond angle 3

''

from the 120° of the undistorted structure (D3h) in the E electronic state could not be detected by GED. The equilibrium bond length computed for this electronic state at the CCSD(T) level of theory (re(V–Cl) = 2.152 Å) was found to be in excellent agreement with r eM value estimated from the thermal-average bond length (rg) by taking into account Morse-type anharmonic correction. Varga Z, Vest B, Schwerdtfeger P, Hargittai M (2010) Molecular geometry of vanadium dichloride and vanadium trichloride: A gas-phase electron diffraction and computational study. Inorg Chem 49 (6):2816-2821

65 CAS RN: 10361-91-8 MGD RN: 361511 GED combined with MS and augmented by QC computations

Ytterbium(III) chloride Ytterbium trichloride Cl3Yb D3h (see comment) YbCl3

2 Inorganic Molecules without Carbon Atoms

Bond Yb–Cl

rg [Å] a 2.416(5)

Bond angle Cl–Yb–Cl

θg [deg] a

73

117.2(10)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainty is estimated total error in units of the last significant digit.

The combined GED/MS experiment was carried out at Teffusion cell = 1170(10) K. The title compound was found to exist in the gas phase mainly in a monomeric form. A small amount of dimeric molecules (2.5(5) mol %) was also detected. The non-planarity of the thermal-average configuration was completely ascribed to shrinkage effect. Thus, the equilibrium configuration was estimated to be planar. Giricheva NI, Shlykov SA, Girichev GV, Chernova EV, Lapykina EA (2009) Molecular structure of ErCl3 and YbCl3 according to the data of the simultaneous electron diffraction and mass spectrometric experiment. J Struct Chem (Engl Transl)/Zh Strukt Khim 50/50(2/2):235-245/251-261

66 CAS RN: 10026-07-0 MGD RN: 592061 GED combined with MS and augmented by QC computations

Tellurium(IV) chloride Tellurium tetrachloride Cl4Te C2v Cl Cl

a

Bonds Te–Cl(ax) Te–Cl(eq)

rg [Å] 2.428(4) 2.289(3)

Bond angles Cl(ax)–Te–Cl(ax) Cl(eq)–Te–Cl(eq)

θg [deg] a

Te Cl Cl

176.7(10) 102.5(7)

Reproduced with permission from The Royal Society of Chemistry [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors.

The combined GED/MS experiment was carried out at 402 K. No decomposition products or oligomeric forms of the title molecule were detected in the mass spectra. The chlorine atoms are bent away from the electron lone pair of tellurium resulting in the Cl(eq)–Te–Cl(eq) and Cl(eq)–Te–Cl(ax) angles smaller than 120 and 90°, respectively. The ra/∠h1 structure was determined previously at 476 K [b]. a. Shlykov SA, Giricheva NI, Titov AV, Szwak M, Lentz D, Girichev GV (2010) The structures of tellurium(IV) halides in the gas phase and as solvated molecules. Dalton Trans 39 (13):3245-3255 b. Kovács A, Martinsen K-G, Konings RJM (1997) Gas-phase vibrational spectrum and molecular geometry of TeCl4. J Chem Soc Dalton Trans 1037-1042

74

2 Inorganic Molecules without Carbon Atoms

67 CAS RN: 16480-60-7 MGD RN: 253628 GED augmented by QC computations

Di-µ-chlorotetrachlorodiiron Iron(III) chloride dimer Cl6Fe2 D2h Cl

Cl Fe

Bonds

rg [Å] a

rg [Å] a

Fe–Cl(t) Fe–Cl(b)

Tnozzle = 460 K 2.129(4) b 2.333(8)

Tnozzle = 900(50) K 2.136(5) b 2.350(12)

θa [deg] a

Bond angles Cl(t)–Fe–Cl(t) Cl(b)–Fe–Cl(b)

Tnozzle = 460 K 123.5(6) 90.6(3)

r eM [Å] a

Cl

Cl Fe

Cl

Cl

2.122(6) 2.317(13)

θa [deg] a

Tnozzle = 900(50) K 123.5 c 93.5(9)

Reprinted with permission. Copyright 2010 American Chemical Society [a]. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ, a systematic error of 0.002r and the variation of the parameter upon reasonable changes of the constrained parameters. b According to results of mPW1PW91/ECP10MDF/cc-pVQZ-PP computations, the terminal Fe–Cl(t) bond length in the dimeric molecule was assumed to be equal to Fe–Cl bond length in the monomer. c Constrained to the value determined in the low-temperature experiment. The GED experiment was carried out at 900(50) K. The title compound was found to exist in the vapor as a mixture of the monomeric (79(3)%) and dimeric molecules. Dynamic model based on the computed PEF was used for the modelling of the ring-puckering largeamplitude motion. Structural differences for the differently puckered structures in respect to the equilibrium configuration with D2h point-group symmetry were assumed at the computed values. Moreover, the experimental data from Ref. [b], obtained at the lower temperature, were also reanalyzed. The comparison of two thermal-average structures allows observation of the temperature effects, i.e. the elongation of the terminal and bridging bonds by 0.007 and 0.017 Å, respectively. Anharmonic vibrational corrections to the experimental bond lengths, ∆r eM = rg − r eM , were estimated using Morse constant. a. Varga Z, Kolonits M, Hargittai M (2010) Gas-phase structures of iron trihalides: A computational study of all iron trihalides and an electron diffraction study of iron trichloride. Inorg Chem 49 (3):1039-1045 b. Hargittai M, Tremmel J, Hargittai I (1980) Molecular structure of dimeric iron trichloride in the vapour phase as determined by electron diffraction. J Chem Soc Dalton Trans 87-89

68 CAS RN: 10049-10-2 MGD RN: 105933 GED supported by QC computations Bond Cr−F

rg [Å] a 1.792(5)

Chromium(II) fluoride Chromium difluoride CrF2 (see comment)

r eM [Å] a 1.778(6)

Copyright 2008 with permission from Elsevier [a].

2 Inorganic Molecules without Carbon Atoms a

75

Parenthesized uncertainty of the last significant digit is presumably estimated total error.

Experimental data obtained in Ref. [b] at 1520(30) K were reanalyzed. +

Three electronic states, 5B2, 5A2 and 5Σ g , with the quasi-linear 5B2 state corresponding to global minimum on

PES, were predicted for the title molecule by CCSD(T) computations. The 5B2 and 5A2 states are arising due to splitting the 5Πg state via Renner-Teller distortion. The ratio of these electronic states at the temperature of the +

experiment was computed to be 5B2: 5A2 : 5Σ g = 82 : 12 : 6 (in %).

In the GED analysis, the Cr–F distance for the 5B2 electronic state was determined adopting the ratio of the electronic states and differences between the Cr–F bond lengths in different electronic states from CCSD(T) computations (in conjunction with modified DZ basis set and PP (small core) for Cr and cc-pVTZ basis set for F). Equilibrium bond length was estimated from rg by taking into account Morse-like anharmonic correction. a. Vest B, Schwerdtfeger P, Kolonits M, Hargittai M (2009) Chromium difluoride: Probing the limits of structure determination. Chem Phys Lett 468 (4-6):143-147 b. Zasorin EZ, Gershikov AG, Spiridonov VP, Ivanov AA (1987) Semirigid model of the deformation-rotation Hamiltonian in the electron diffraction analysis of triatomic molecules. III. Chromium difluoride. Russ J Struct Chem/Zh Strukt Khim 28/28(5/5), 680-684/56-60

69 CAS RN: 189063-72-7 MGD RN: 210966 IR

(Dihydrogen-κH,κH')chromium (1+) ion Chromium (1+) ion – dihydrogen (1/1) CrH2 C2v H

Distance Rcm b

Cr

r0 [Å] a 2.023

+

H

Reproduced with permission of AIP Publishing.

a b

Uncertainty was not given in the original paper. Distance between Cr+ and the midpoint of D–D.

The rotationally resolved IR spectrum of the binary van der Waals complex of the chromium ion with dideuterium was recorded in a supersonic jet in the region of the D–D stretching fundamental between 2742 and 2820 cm-1 by detecting Cr+ photofragments. The ionic complex was produced by passing deuterium over a laserablated chromium rod. The partial r0 structure was determined from the ground-state rotational constants of CrD2 isotopic species under the assumption that the D–D distance was not changed upon complexation. The molecule was found to have a T-shaped structure. Dryza V, Bieske EJ (2009) The Cr+-D2 cation complex: Accurate experimental dissociation energy, intermolecular bond length, and vibrational parameters. J Chem Phys 131(16):164303/1-164303/6 doi:10.1063/1.3250985

70 CAS RN: MGD RN: 379249 MW supported by DFT calculations

Copper(I) fluoride – dihydrogen (1/1) CuFH2 C2v Cu

F

H2

76

Distances Cu–F Rcm b H– H

2 Inorganic Molecules without Carbon Atoms

rs [Å] a 1.7409(1) 1.5246(5) 0.750593 c

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Assumed at the experimental value for H2. b

The rotational spectrum of the binary complex of copper(I) fluoride with dihydrogen was recorded by a pulsedjet Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 26.5 GHz. The r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 65Cu, D, D2, 65Cu/D and 65Cu/D2). The molecule was found to have the T-shaped structure. Frohman DJ, Grubbs GS, Yu Z, Novick SE (2013) Probing the chemical nature of dihydrogen complexation to transition metals, a gas phase case study: H2-CuF. Inorg Chem 52(2):816-822

71 CAS RN: 1379616-42-8 MGD RN: 489334 MW supported by ab initio calculations

Copper(I) fluoride – ammonia (1/1) CuFH3N C3v N Cu

Distances Cu–F Cu…N N– H

r0 [Å] a 1.74919(55) 1.89276(13) 1.0187 b

rs [Å] a

Angle H–N–Cu

θ0 [deg] a

θs [deg] a

111.462(26)

F

H

H H

1.89(5)

111.500(50)

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Assumed.

The rotational spectra of the binary complex of copper(I) fluoride with ammonia was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The partial r0 and rs structures were determined from the ground-state rotational constants of four isotopic species (main, 65Cu, D3 and 15N). Bittner DM, Stephens SL, Zaleski DP, Tew DP, Walker NR, Legon AC (2016) Gas phase complexes of H3N⋅⋅⋅CuF and H3N⋅⋅⋅CuI studied by rotational spectroscopy and ab initio calculations: the effect of X (X = F, Cl, Br, I) in OC⋅⋅⋅CuX and H3N⋅⋅⋅CuX. Phys Chem Chem Phys 18(19):13638-13645

72

Copper hydrogen sulfide

2 Inorganic Molecules without Carbon Atoms

77

CAS RN: 227747-32-2 MGD RN: 152018 MW

Copper hydrosulfide CuHS Cs S

Bonds Cu–S S–H

rz [Å] a 2.09309(14) 1.3507(20)

Bond angle Cu–S–H

θz [deg] a

H

Cu

93.67(13)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

The rz structure was determined from the previously published ground-state rotational constants of four isotopic species. Okabayashi T, Yamamoto T, Mizuguchi D, Okabayashi EY, Tanimoto M (2012) Microwave spectroscopy of silver hydrosulfide AgSH. Chem Phys Lett 551:26-30

73 CAS RN: MGD RN: 500969 MW supported by ab initio calculations

Distances

r0 [Å] a

Angle

θ0 [deg] a

Cu–I Cu…S

φ

b

Copper(I) iodide – hydrogen sulfide (1/1) CuH2IS

Cs

Cu

I

S H

H

2.3603(83) 2.175(14)

75.00(47)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit. Angle between Cu…S and the C2 axis of the H2S subunit.

The rotational spectra of the binary complex of copper(I) iodide with hydrogen sulfide were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The complex was produced by a gas phase reaction of laser-ablated copper with trifluoroiodomethane and hydrogen sulfide. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 65 Cu, D, D2, 65Cu/D and 65Cu/D2) under the assumption that the structural parameters of the hydrogen sulfide subunit were not changed upon complexation. Medcraft C, Bittner DM, Tew DP, Walker NR, Legon AC (2016) Geometries of H2S⋅⋅⋅MI (M = Cu, Ag, Au) complexes studied by rotational spectroscopy: The effect of the metal atom. J Chem Phys 145(19):194306/1194306/10

78

2 Inorganic Molecules without Carbon Atoms

[http://dx.doi.org/10.1063/1.4967477]

74 CAS RN: 665007-62-5 MGD RN: 489162 MW supported by ab initio calculations

Copper(I) iodide – ammonia (1/1) CuH3IN C3v N Cu a

r0 [Å] 2.35525(46) 1.9357(13) 1.0185 b

rs [Å]

Angle H–N…Cu

θ0 [deg] a

θs [deg] a

111.430(54)

H

H H

a

Distances Cu–I Cu…N N– H

I

1.9361(13)

111.535(30)

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Assumed.

The rotational spectra of the binary complex of copper(I) iodide with ammonia were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The partial r0 and rs structures were determined from the ground-state rotational constants of five isotopic species (main, 65Cu, D3, 15N and 65Cu/D3). Bittner DM, Stephens SL, Zaleski DP, Tew DP, Walker NR, Legon AC (2016) Gas phase complexes of H3N⋅⋅⋅CuF and H3N⋅⋅⋅CuI studied by rotational spectroscopy and ab initio calculations: the effect of X (X = F, Cl, Br, I) in OC⋅⋅⋅CuX and H3N⋅⋅⋅CuX. Phys Chem Chem Phys 18(19):13638-13645

75 CAS RN: 15474-63-2 MGD RN: 216590 GED combined with MS and augmented by QC computations

Bond Dy–I

rg [Å] a 2.812(6)

Bond angle I–Dy–I

θg [deg] a

Dysprosium(III) iodide Dysprosium triiodide DyI3 D3h (see comment)

117.25(10)

Copyright 2010 with permission from Elsevier [a].

a

Parenthesized uncertainty in units of the last significant digit is estimated total error.

The combined GED/MS experiment was carried out at 1117(10) K. Besides the monomeric molecules, a small amount of the dimeric molecules (1.5(9) mol %) was detected.

2 Inorganic Molecules without Carbon Atoms

79

The non-planarity of the thermal-average structure of the monomer was completely ascribed to shrinkage effect, i.e. the equilibrium configuration was estimated to be planar. Anharmonic vibrational corrections to the experimental bond lengths rg(Ln–I) in lanthanide trihalides, ∆re = rg – re, were simply estimated to be between 0.002 and 0.018(1) Å using Morse constants. a. Shlykov SA, Giricheva NI, Lapykina EA, Girichev GV, Oberhammer H (2010) The molecular structure of Tbl3, Dyl3, Hol3 and Erl3 as determined by synchronous gas-phase electron diffraction and mass spectrometric experiment assisted by quantum chemical calculations. J Mol Struct 978 (1-3):170-177 GED combined with MS and augmented by QC computations Bond

rg [Å] a

Dy–I

2.828(6)

Bond angle I–Dy–I

θa [deg] a

D3h (see comment)

M

r e [Å] a

2.808(9)

116.4(18)

Reproduced with permission from The Royal Society of Chemistry [b].

a

Parenthesized uncertainty in units of the last significant digit is estimated total error including 1.4σ, a systematic error of 0.002r and variation of the parameter upon reasonable changes of the constrained parameters. The GED experiment was carried out at Tnozzle = 1150(50) K. The title compound was found to exist as a mixture of monomeric (83(3)%) and dimeric (17(3)%) molecules. The equilibrium bond length computed at the CCSD(T) level of theory (re(Dy–I) = 2.812 Å) was found to be in a M

good agreement with r e value simply estimated from the thermal-average bond length taking into account the Morse-type anharmonic vibrational correction. The deviation of the experimental structure from a planar configuration was completely ascribed to shrinkage effect, i.e. the equilibrium structure was estimated to be planar (with ∠e(I–Dy–I) = 120°). b. Varga Z, Groen CP, Kolonits M, Hargittai M (2010) Curious matrix effects: A computational, electron diffraction, and vibrational spectroscopic study of dysprosium triiodide. Dalton Trans 39 (27):6221-6230

76 CAS RN: 92618-67-2 MGD RN: 370789 GED supported by MS and augmented by QC computations

Di-µ-iodotetraiododidysprosium Dysprosium(III) iodide dimer Dy2I6 D2h (see comment) I

I Dy

Bonds Dy–I(t) Dy–I(b)

rg [Å] a 2.816(8) b 3.029(20) c

Bond angles I(t)–Dy–I(t) I(b)–Dy–I(b)

θa [deg] a 120(36) 92(5)

Reproduced with permission from The Royal Society of Chemistry.

I

I Dy

I

I

80

2 Inorganic Molecules without Carbon Atoms

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1.4σ, a systematic error of 0.002r and variation of the parameter upon reasonable changes of the constrained parameters. b Difference between ra(Dy–I(t)) and ra(Dy–I) in the monomeric molecule was adopted from MP2 computation. c Difference between ra(Dy–I(t)) and ra(Dy–I(b)) was adopted from computation as above. The GED experiment was carried out at Tnozzle = 1150(50) K. Dysprosium triiodide sample was found to exist as a mixture of monomeric (83(3)%) and dimeric (17(3)%) forms. The high-temperature gas IR spectrum confirmed the presence of dimeric molecules. The computed equilibrium structure of dimeric molecule has D2h symmetry, whereas the experimental thermalaverage structure appeared to be puckered (C2v symmetry). Varga Z, Groen CP, Kolonits M, Hargittai M (2010) Curious matrix effects: A computational, electron diffraction, and vibrational spectroscopic study of dysprosium triiodide. Dalton Trans 39 (27):6221-6230

77 CAS RN: 13813-42-8 MGD RN: 216393 GED combined with MS and augmented by QC computations

Bond Er–I

rg [Å] a 2.789(6)

Bond angle I–Er–I

θg [deg] a

Erbium(III) iodide Erbium triiodide ErI3 D3h (see comment)

117.7(9)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit is estimated total error.

The combined GED/MS experiment was carried out at 1102(10) K. Besides the monomeric molecules, a small amount of the dimeric molecules (1.5(13) mol %) was detected. The non-planarity of the thermal-average structure of the monomer was completely ascribed to shrinkage effect, i.e. the equilibrium configuration was estimated to be planar. Anharmonic vibrational corrections to the experimental bond lengths rg(Ln–I) in lanthanide trihalides, ∆re = rg – re, were simply estimated to be between 0.002 and 0.018(1) Å using Morse constants. Shlykov SA, Giricheva NI, Lapykina EA, Girichev GV, Oberhammer H (2010) The molecular structure of Tbl3, Dyl3, Hol3 and Erl3 as determined by synchronous gas-phase electron diffraction and mass spectrometric experiment assisted by quantum chemical calculations. J Mol Struct 978 (1-3):170-177

78 CAS RN: 12206-67-6 MGD RN: 436316 IR

Fluoronium FH2 C2v F

Bond

re [Å] a

H

H

2 Inorganic Molecules without Carbon Atoms

F–H

0.9608(6)

Bond angle H–F–H

θe [deg] a

81

112.2(2)

Reprinted with permission. Copyright 2013 American Chemical Society. a

Parenthesized estimated uncertainty in units of the last significant digit.

The rotationally resolved vibrational spectrum of fluoronium was recorded by an FTIR spectrometer in the 3 and 7 µm regions. The ion was produced by a hollow cathode discharge of a mixture of fluorine, hydrogen and helium. All three fundamental bands were analyzed. The rotation-vibration interaction constant was determined using the determined rotational constants of the first excited vibrational states together with the previously published ground-state rotational constants. Fujimori R, Hirata Y, Morino I, Kawaguchi K (2013) FTIR spectroscopy of three fundamental bands of H2F+. J Phys Chem A 117(39):9882-9888

79 CAS RN: 38005-28-6 MGD RN: 466277 GED augmented by QC computations

Phosphorazidic difluoride Difluorophosphoryl azide F2N3OP Cs (syn) O N

a

Bonds N(2)≡N(3) N(1)=N(2) P–F P–N P=O

rh1 [Å] 1.130(2) 1.251(3) 1.5316(6) 1.657(2) 1.437(4)

Bond angles F–P–F O–P–N F–P–N P–N=N N=N≡N

θh1 [deg] a

P

N N

F F

98.8(3) 118.9(3) 101.1(7) 117.8(5) 172(2)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

Two conformers, syn and anti, characterized by the synperiplanar and antiperiplanar O=P−N=N torsional angles, respectively, were predicted by QC computations (MP2 and B3LYP in conjunction with 6-311+G(3df) basis set and CBS-QB3). The syn conformer was predicted to be lower in energy than the anti one by 5-6 kJ mol−1. However, the best fit to the GED intensities was obtained for 0% contribution of the anti conformer. Therefore, the single conformer model was used in the final refinements of the syn conformer structure. The GED experiment was carried out at room temperature. In the GED analysis, the torsion of the N3 group around the P−N bond with predicted frequency of 35 cm−1 (MP2/TZVPP) was considered as a large-amplitude motion and described by a model of pseudo-conformers.

82

2 Inorganic Molecules without Carbon Atoms

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from MP2/TZVPP computation. Wu Z, Li HM, Zhu BF, Zeng XQ, Hayes SA, Mitzel NW, Beckers H, Berger RJF (2015) Conformational composition, molecular structure and decomposition of difluorophosphoryl azide in the gas phase. Phys Chem Chem Phys 17 (14):8784-8791

80 CAS RN: 37388-50-4 MGD RN: 387410 GED supported by IR and augmented by QC computations

Phosphorazidous difluoride Difluorophosphine azide F 2N 3P Cs (syn) Cs (anti) F

N

Bonds P–F P–N N=N N≡N Bond angles F–P–F P–N=N N=N≡N Dihedral angles F–P–N=N

a

syn 1.579(1) 1.710(3) 1.250(3) 1.125(3)

syn 95.9(3) 118.3(4) 178(1)

syn 48.4(1)

rh1 [Å] anti 1.572(2) 1.716(3) 1.247(3) 1.127(3)

P F

N N

syn

θh1 [deg] a

anti 96.4(2) 117.7(5) 177(1) anti

τh1 [deg] a

anti 131.5(2)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Uncertainties in the last digits given in parenthesis are not identified, presumably estimated total errors.

Two conformers, syn and anti, characterized by the synperiplanar and antiperiplanar positions of the N=N≡N group relative to the bisector of the F–P–F angle, respectively, were identified in the GED (Tnozzle ≈ 298 K) and IR experiments. The conformers were found to exist in an almost equimolar mixture. The syn conformer was found to be slightly more stable than the anti conformer by ∆H°=2.4(6) kJ mol–1 as determined by gas-phase temperature-dependent IR spectroscopy. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from B3LYP/6-311G(3df) computations. In the GED analysis, the large-amplitude torsional motion of the azido group in the anti conformer was described by a model of pseudo-conformers. Differences between parameters of the conformers were adopted from QC calculations. Zeng XQ, Beckers H, Willner H, Berger RJF, Hayes SA, Mitzel NW (2011) Structure and conformational properties of azido(difluoro)phosphane, F2PN3. Eur J Inorg Chem (6):895-905

81

Di-µ-fluorodisodium

2 Inorganic Molecules without Carbon Atoms

83

CAS RN: 12285-64-2 MGD RN: 746515 GED combined with MW and augmented by ab initio computations

Bond Na–F

re [Å] a 2.073(4)

Bond angle F–Na–F

θe [deg] a

Sodium fluoride dimer F2Na2 D2h

92.8(6)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainty in unit of the last significant digit is the estimated standard deviation.

Both monomeric and dimeric molecules of sodium fluoride were detected in the gas phase at Tnozzle = 1123 K. The proportion of NaF units existing as dimer was determined to be 0.20(2). Anharmonic vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using PES from MP2_full/6-311+G(d) computation. The determined structure was found to be close to that from CCSD(T)/aug-cc-pwCVQZ computation. Wann DA, Rankin DWH, McCaffrey PD, Martin JML, Mawhorter RJ (2014) Equilibrium gas-phase structures of sodium fluoride, bromide, and iodide monomers and dimers. J Phys Chem A 118 (10):1927-1935

82 CAS RN: 13537-33-2 MGD RN: 133409 MW augmented by ab initio calculations

Fluorosilane Silyl fluoride FH3Si C3v H

H

Si a

a

a

Bonds F–Si Si–H

r0 [Å] 1.5953(9) 1.4743(14)

r [Å] 1.5882(9) 1.4691(1)

r [Å] 1.59048(6) 1.46948(9)

Bond angle F–Si–H

θ0 [deg] a

θ (1) [deg] a m

θ see [deg] a

108.13(15)

(1) m

108.304(7)

se e

H

F

108.304(9)

Copyright 2010 with permission from Elsevier [a].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

The semiexperimental equilibrium structure r see was determined from the previously published ground-state rotational constants of eight isotopic species by taking into account rovibrational corrections calculated with the CCSD(T)/cc-pCVTZ harmonic and anharmonic (cubic) force fields. a. Puzzarini C, Cazzoli G, Gauss J (2010) Rotational spectra of isotopic species of silyl fluoride. Part II: Theoretical and semiexperimental equilibrium structure. J Mol Spectrosc 262(1):37-41

84

2 Inorganic Molecules without Carbon Atoms

MW, IR

Bonds Si–H Si–D Si–F Bond angles H–Si–H H–Si–F D–Si–D D–Si–F

C3v

r0 [Å] a 1.4755(29) 1.5931(26)

θ0 [deg] a 110.472(324) 108.452(561)

re [Å] a 1.46644(447) 1.59146(237)

θe [deg] a

110.805(506) 108.102(292)

Reprinted by permission of Taylor & Francis Ltd. Final version received 23 May 2016 [b] a

Parenthesized uncertainties in units of the last significant digit.

The rotation-vibration interaction constants and equilibrium rotational constants were derived from the data of previously published high-resolution FTIR and millimeter-wave measurements. The r0 structure was determined from the ground state rotational constants of two isotopic species (main and D3). b. Najib H (2016) Experimental values of the rotational and vibrational constants of deuterated silyl fluoride. Mol Phys 114(19):2831-2837

83 CAS RN: 16904-65-7 MGD RN: 142861 IR supported by ab initio calculations

Distance Rcm b

Hydrogen fluoride trimer F 3H 3 C3h H

F

3

r0 [Å] a 2.600(1)

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainty in units of the last significant digit. Distance between centers of mass in two monomer subunits.

The rotationally resolved vibrational spectrum of the hydrogen fluoride trimer was recorded in a supersonic jet in the region of two intermolecular librations, namely the in-plane ν6 and the out-of-plane ν4 bending fundamentals at about 494 and 602 cm-1, respectively. The FTIR spectra were obtained using synchrotron radiation. The partial r0 structure was determined from the obtained ground-state rotational constants under the assumption that the H–F distance was not changed upon complexation. Asselin P, Soulard P, Madebène B, Goubet M, Huet TR, Georges R, Pirali O, Roy P (2014) The cyclic ground state structure of the HF trimer revealed by far infrared jet-cooled Fourier transform spectroscopy. Phys Chem Chem Phys 16(10):4797-4806

2 Inorganic Molecules without Carbon Atoms

84 CAS RN: 7783-54-2 MGD RN: 196598 MW, IR

85

Trifluoroamine Nitrogen trifluoride F 3N C3v N

Bond N– F

r0 [Å] a 1.37132(66)

re [Å] a 1.36757(58)

Bond angle F–N–F

θ0 [deg] a

θe [deg] a

102.11761(46)

F

F

F

101.8513(10)

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit.

The previously published and additionally measured microwave and high-resolution IR spectra of the ground and vibrationally excited states were analyzed. The r0 structure was determined from the improved ground-state rotational constants. The experimental equilibrium structure re was obtained by taking into account the previously published rovibrational interaction constants αC and αB. Najib H (2015) Experimental values of the rotational and vibrational constants and equilibrium structure of nitrogen trifluoride. J Mol Spectrosc 312:1-5

85 CAS RN: 7783-55-3 MGD RN: 933660 MW, IR

Trifluorophosphine Phosphorous trifluoride F 3P C3v P

Bond P –F Bond angle F–P–F

r0 [Å] a 1.56324405(11)

θ0 [deg] a

97.752232(29)

re [Å] a 1.560986(43)

F

F F

θe [deg] a

97.566657(64)

Copyright 2014 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit.

The previously published and additionally measured MW and high-resolution IR spectra of the ground and vibrationally excited states were analyzed. The r0 structure was determined from the improved ground-state rotational constants. The experimental equilibrium structure re was obtained by taking into account the previously published rovibrational interaction constants αC and αB. Najib H (2014) Experimental rovibrational constants and equilibrium structure of phosphorus trifluoride. J Mol Spectrosc 305:17-21

86

2 Inorganic Molecules without Carbon Atoms

86 CAS RN: 24331-65-5 MGD RN: 916047 GED augmented by QC computations

Bonds P−F S–P P(1)–F P(2)–F S–P(1) S–P(2) Bond angles S−P−F F−P−F P−S−P S–P(1)–F S–P(2)–F P(1)–S–P(2)

Thiophosphorous tetrafluoride Bis(difluorophosphino) sulfide F4P2S C2v (I) Cs (II) F

ra3,1 [Å] a C2v Cs 1.564(2) b 1.564(2) b b 2.119(2) 2.119(2) b c,d 1.564(2) 1.562(5) c,d 1.568(5) c,d c,e 2.116(2) 2.133(5) c,e 2.111(5) c,e

F

S

P

P

F

F

I

θa3,1 [deg] a

C2v 100.4(2) b 98.1(3) b 94.6(4) b 100.1(2) c,f 91.3(3) c,g

Cs 100.4(2) b 98.1(3) b 94.6(4) b 99.3(5) c,f 102.1(7) c,f 97.9(6) c,g

Reprinted with permission. Copyright 2009 American Chemical Society [a].

II

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value for both conformers. c Dependent parameter. d Differences between the P–F bond lengths were restrained to the values from MP2/aug-cc-pVTZ computation. e Differences between the S–P bond lengths were restrained to the values from computation as indicated above. f Differences between the S–P–F bond angles were restrained to the values from computation as indicated above. g Difference between the P–S–P bond angles was restrained to the value from computation as indicated above. b

The GED experiment was carried out at Tnozzle =298 K in Ref. [b]. Three conformers, I, II and III, with C2v, Cs and C2 symmetry, respectively, were predicted by B3LYP/aug-ccpVQZ computations. An amount of the C2 conformer was predicted to be small (1.4% at room temperature). Therefore, only the C2v and Cs conformers were considered in the GED analysis. Their ratio was determined to be I : II = 87(5) : 13 (in %). Vibrational corrections to the experimental internuclear distances, ∆ra3,1 = ra – ra3,1, were calculated from the B3LYP/6-31G(d) quadratic and cubic force constants taking into account non-linear kinematic effects. a. Reilly AM, Wann DA, Rankin DWH (2009) What makes the huge 31P-31P coupling constants in S(PF2)2 and Se(PF2)2 vary so much with temperature? J Phys Chem A 113 (5):938-942 b. Arnold DEJ, Gundersen G, Rankin DWH, Robertson HE (1983) Gas-phase molecular structures of bis(difluorophosphino) sulphide, S(PF2)2, bis(difluorophosphino) selenide, Se(PF2)2, and difluoro(methylthio)phosphine, PF2(SMe), determined by electron diffraction. J Chem Soc Dalton Trans 19891994

2 Inorganic Molecules without Carbon Atoms

87 CAS RN: 15192-26-4 MGD RN: 208485 GED combined with MS and augmented by QC computations

Bonds Te–F(ax) Te–F(eq)

rg [Å] a 1.899(4) 1.846(4)

Bond angles F(ax)–Te–F(ax) F(eq)–Te–F(eq)

θg [deg] a

87

Tellurium(IV) fluoride Tellurium tetrafluoride F4Te C2v F

F Te

F F

164.3(12) 99.5(3)

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors.

The combined GED/MS experiment was carried out at 358 K. No decomposition products or oligomeric forms of the title molecule were detected in the mass spectra. The fluorine atoms are bent away from the electron lone pair of tellurium resulting in the F(eq)–Te–F(eq) and F(eq)– Te–F(ax) angles smaller than 120 and 90°, respectively. Shlykov SA, Giricheva NI, Titov AV, Szwak M, Lentz D, Girichev GV (2010) The structures of tellurium(IV) halides in the gas phase and as solvated molecules. Dalton Trans 39(13):3245-3255

88 CAS RN: 1801432-57-4 MGD RN: 457312 MW

Sulfur hexafluoride – ammonia (1/1) F6H3NS C3v F

Distance Rcm b

r0 [Å] a 4.15772(2)

Angle

θ0 [deg] a

φ

c

F

F S

F

N H

F

H H

F

46.3(2)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainty in units of the last significant digit. Distance between the centers of mass of both subunits. c Angular oscillation of the ammonia subunit about its C3 axis. b

The rotational spectrum of the binary complex was recorded by a broadband chirped-pulse FTMW spectrometer in the frequency range between 8 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 15 N, D3 and 15N/34S) under the assumption that the geometries of the monomer subunits were not changed upon complexation. The C3 axis of the ammonia subunit is aligned with the local C3 axis of the sulfur hexafluoride subunit.

88

2 Inorganic Molecules without Carbon Atoms

Bittner DM, Zaleski DP, Stephens SL, Walker NR, Legon AC (2015) The σ-hole interaction between sulfur hexafluoride and ammonia characterized by broadband rotational spectroscopy. ChemPhysChem 16(12):26302634

Bis(pentafluoro-λ6-sulfanyl)amino Bis(pentafluorosulfanyl)amidogen F10NS2 C2

89 CAS RN: 100312-10-5 MGD RN: 572234 GED

F

F

Bonds N–S S–F

ra [Å] 1.692(4) 1.561(2) b

Bond angles S–N–S F(ax)–S–F(eq) c

θa [deg] a

Dihedral angle

τa [deg] a

τ

d

F

a

F

F

S

F

S

N

F

F F

F

135.1(5) 88.8(3)

30.8(4)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Mean value. c F(ax) and F(eq) are axial and equatorial F atoms, respectively. d Torsional angle around the S–N bond; τ = 0° when two equatorial fluorine atoms are perpendicular to the S–N–S plane. b

The GED experiment was carried out at Tsample = 218 K. Each of the SF5 groups was assumed to possess local C4v symmetry. The structure of this short-living radical was found to be similar to that of FN(SF5)2. Nielsen JB, Zylka P, Kronberg M, Zeng XQ, Robinson KD, Bott SG, Zhang HM, Atwood JL, Oberhammer H, Willner H, Thrasher JS (2017) Solid- and gas-phase structures and spectroscopic and chemical properties of tris(pentafluorosulfanyl)amine, N(SF5)3, and bis(pentafluorosulfanyl)aminyl radical, . N(SF5)2. J Mol Struct 1132:11-19

1,1,1,1,1-Pentafluoro-N,N-bis(pentafluoro-λ6-sulfanyl)-λ6-sulfanamine Tris(pentafluorosulfanyl)amine F15NS3 D3

90 CAS RN: 100312-09-2 MGD RN: 572420 GED

F

F

Bonds N–S S–F

a

ra [Å] 1.829(6) 1.561(2) b

F

F

S

F

F

F

S

θa [deg] a 119.7(2)

F F F

F

F F

N

F

F

Bond angles S–N–S

S

2 Inorganic Molecules without Carbon Atoms

F(ax)–S–F(eq) c

88.6(3) b

Dihedral angle

τa [deg] a

τ

d

89

27.2(10)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Mean value. c F(ax) and F(eq) are axial and equatorial F atoms, respectively. d Torsional angle around the S–N bond; τ = 0° when two equatorial fluorine atoms are perpendicular to the plane of the sulfur atoms. b

The GED experiment was carried out at 293 K. Each of the SF5 groups was assumed to possess local C4v symmetry. Easy thermal decomposition into aminyl and SF5 radicals was explained by the unusually long N–S bond. Nielsen JB, Zylka P, Kronberg M, Zeng XQ, Robinson KD, Bott SG, Zhang HM, Atwood JL, Oberhammer H, Willner H, Thrasher JS (2017) Solid- and gas-phase structures and spectroscopic and chemical properties of tris(pentafluorosulfanyl)amine, N(SF5)3, and bis(pentafluorosulfanyl)aminyl radical, . N(SF5)2. J Mol Struct 1132:11-19

91 CAS RN: 7783-86-0 MGD RN: 105877 GED supported by MS and augmented by QC computations Bonds Fe–I I…I

rg [Å] a 2.478(11) c 4.856(26)

Bond angle I–Fe–I

θa [deg] a

Iron(II) iodide Iron diiodide FeI2 D∞h (see comment)

r eM [Å] a,b 2.464(16)

157(3)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including random and systematic errors. b Estimated from the thermal-average bond length by taking into account Morse-like anharmonic correction and the effect of centrifugal distortion. c Difference to the terminal Fe–I bond length in the dimeric molecule was kept at the computed value. The GED experiment was carried out at Tnozzle = 850 K. The title compound was found to exist as a mixture of monomeric (72(5)%) and dimeric (28(5)%) species. Due to shrinkage effect, the thermal-average structure of the monomer is non-linear one with C2v symmetry, while the equilibrium structure is linear with D∞h point-group symmetry. The comprehensive QC computations at various levels of theory (mPW1PW91, MRCI, CCSD(T), etc.) predicted a linear structure in the electronic ground state (5Δg).

90

2 Inorganic Molecules without Carbon Atoms

Varga Z, Kolonits M, Hargittai M (2011) Iron dihalides: Structures and thermodynamic properties from computation and an electron diffraction study of iron diiodide. Struct Chem 22 (2):327-336

92 CAS RN: 92785-63-2 MGD RN: 554646 GED supported by MS and augmented by QC computations

Di-µ-iododiiododiiron Iron diiodide dimer Fe2I4 D2h (see comment) I

I

Bonds Fe–I(t) Fe–I(b)

rg [Å] a 2.480(11) c,d 4.683(12) d

Bond angle I(b)–Fe–I(b)

θa [deg] a

r eM [Å] a,b 2.469(15) c,d 4.660(27) d

Fe

Fe

I

I

103(2)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including random and systematic errors as well as the effects of constraints. b Estimated from the thermal-average bond length by taking into account Morse-like anharmonic correction. c Difference to the Fe–I bond length in the monomeric molecule was adopted from computation at the level of theory as indicated below. d Difference between the Fe–I(t) and Fe–I(b) bond lengths was kept at the computed value. The GED experiment was carried out at Tnozzle = 850 K. Both monomeric (72(5)%) and dimeric species of the title compound were detected in the vapor. According to predictions of mPW1PW91, CASSCF and MRCI computations, the dimeric molecule is planar (D2h point-group symmetry) in the electronic ground state (9Ag). Varga Z, Kolonits M, Hargittai M (2011) Iron dihalides: Structures and thermodynamic properties from computation and an electron diffraction study of iron diiodide. Struct Chem 22 (2):327-336

93 CAS RN: 13572-98-0 MGD RN: 235278 GED combined with MS and augmented by DFT computations

Bond Gd–I

rg [Å] a 2.840(6)

Bond angle I–Gd–I

θg [deg] a 117.3(9)

Reproduced with permission of SNCSC.

Gadolinium(III) iodide Gadolinium triiodide GdI3 D3h (see comment) GdI3

2 Inorganic Molecules without Carbon Atoms

91

a

Parenthesized uncertainty in units of the last significant digit is estimated total error including 2.5σ and a systematic error of 0.002r.

The GED experiment was carried out at 1100(10) K. Besides the monomeric molecules, a small percentage of the dimeric form (2.5(12) mol %) was detected in the saturated vapor of the title compound. Differences between the bond lengths of dimer and monomer were adopted from B3LYP computation. Although the thermal-average structure of a monomeric molecule is non-planar (C3v symmetry), the equilibrium structure was estimated to be planar (D3h point-group symmetry) accounting for shrinkage effect. According to prediction of computations, the molecule is planar with D3h symmetry. Giricheva NI, Shlykov SA, Lapykina EA, Oberhammer H, Girichev GV (2011) The molecular structure of PrI3 and GdI3 as determined by synchronous gas-phase electron diffraction and mass spectrometric experiment assisted by quantum chemical calculations. Struct Chem 22 (2):385-392

94 CAS RN: 36098-67-6 MGD RN: 136196 MW

Iodosilylene HISi Cs Si

Bonds Si–I Si–H

r0 [Å] a 2.46143(9) 1.5405(1)

Bond angle H–Si–I

θ0 [deg] a

I

H

92.68(6)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded by a pulsed-jet chirped-pulse FTMW spectrometer in the frequency region between 6 and 26 GHz. The transient species was formed by a DC discharge of an iodosilane precursor. The r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 29Si, 30 Si, 29Si/D and D). Kang L, Gharaibeh MA, Clouthier DJ, Novick SE (2012) Fourier transform microwave spectroscopy of the reactive intermediate monoiodosilylene, HSiI and DSiI. J Mol Spectrosc 271(1):33-37

95 CAS RN: 1310-61-8 MGD RN: 360563 MW

Bonds K–S S–H

r0 [Å] a 2.806(1) 1.357(1)

Potasium hydrogen sulfide HKS Cs

S K

H

92

Bond angle K–S–H

2 Inorganic Molecules without Carbon Atoms

θ0 [deg] a 95.0(1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of potassium hydrogen sulfide (1A' electronic ground state) were recorded by a BalleFlygare type FTMW spectrometer in the frequency region between 3 and 57 GHz and by a millimeter-wave direct absorption spectrometer in the range between 260 and 300 GHz. The transient species were produced by a DC discharge of laser-ablated potassium with hydrogen sulfide. The r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D). Bucchino MP, Sheridan PM, Young JP, Binns MKL, Ewing DW, Ziurys LM (2013) Trends in alkali metal hydrosulfides: A combined Fourier transform microwave/millimeter-wave spectroscopic study of KSH (X1A'). J Chem Phys 139(21):214307/1-214307/10 [http://dx.doi.org/10.1063/1.4834656]

96 CAS RN: 14332-28-6 MGD RN: 136067 MW

Nitrosyl hydride HNO Cs N

Bonds H– N N=O Bond angle H–N=O

r0 [Å] a 1.068(4) 1.2107(8)

r (1) [Å] a m 1.0506(2) 1.20880(2)

θ0 [deg] a

θ (1) [deg] a m

108.1(3)

H

O

108.073(6)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectrum of the title compound was recorded by a chirped-pulse Fourier transform millimeterwave spectrometer in the spectral range between 60 and 90 GHz. Only the isotopically enriched samples H15N16O, H14N18O and D15N16O were observed. The r0 and r (1) structures were obtained from the determined ground-state rotational constants of the 15N, 18O and m 15 N/D isotopic species together with the previously published constants of the main and deuterated species. The r (1) structure was suggested to be a good approximation of an equilibrium structure. m Zaleski DP, Prozument K (2017) Pseudo-equilibrium geometry of HNO determined by an E-band CP-FTmmW spectrometer.” Chem Phys Lett 680(978):101-108

97 CAS RN: 29335-37-3 MGD RN: 471320

Thionitrous acid HNOS

2 Inorganic Molecules without Carbon Atoms

93

MW augmented by ab initio calculations

N HS

Bonds H– S S–N N=O Bond angles H–S–N S–N=O

syn r0 [Å] a 1.38(7) 1.85(3) 1.19(3)

θ0 [deg] a 91(4) 116(1)

r [Å] 1.345(4) 1.834(2) 1.181(2)

anti r0 [Å] a 1.32(5) 1.87(3) 1.18(3)

r see [Å] a 1.335(3) 1.852(2) 1.177(2)

θ see [deg] a

θ0 [deg] a

θ see [deg] a

a

se e

95.2(2) 115.94(8)

89(2) 114(1)

Cs O

90.1(1) 114.63(7)

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

syn

anti

The rotational spectra of thionitrous acid were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 43 GHz. The transient species was produced by a gas phase reaction of NO with H2S. Two conformers were observed, syn and anti. For each conformer, the r0 structure was determined from the ground-state rotational constants of five isotopic species (main, D, 34S, 15N and 18O). The semiexperimental equilibrium structure r see was obtained taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)/aug-cc-pV(Q+d)Z harmonic and anharmonic (cubic) force fields. Nava M, Martin-Drumel MA, Lopez CA, Crabtree KN, Womack CC, Nguyen TL, Thorwirth S, Cummins CC, Stanton JF, McCarthy MC (2016) Spontaneous and selective formation of HSNO, a crucial intermediate linking H2S and nitroso chemistries. J Amer Chem Soc 138(36):11441-11444

98 CAS RN: 877456-58-1 MGD RN: 402835 MW augmented by ab initio calculations

Hydroperoxyimidogen HNO2 Cs (anti) O

HO

Bonds H– O O– O O– N

r0 [Å] a 0.937(28) 1.943(12) 1.137(13)

r see [Å]a 0.9698(10) 1.9149(5) 1.1264(5)

Bond angles H– O– O O– O– N

θ0 [deg] a

θ see deg] a

96.1(13) 115.7(6)

97.21(5) 115.65(2)

N

94

2 Inorganic Molecules without Carbon Atoms

Reprinted with permission from AAAS. a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of the title compound were recorded in a supersonic molecular beam by an FTMW spectrometer and double resonance techniques in the frequency region between 5 and 93 GHz. The transient species HOON were produced in a discharge of NO and water. This isomer was detected in the mixture with the much more stable isomer nitrous acid in the ratio 3 : 97. Only the anti conformer of HOON molecule was detected. The r0 structure of this conformer was determined from the ground-state rotational constants of five isotopic species (main, two 18O, 15N and D). The semiexperimental equilibrium structures was obtained by taking into account the rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)/aug-cc-pVTZ quadratic and cubic force constants. The molecule was found to have an unusually long O–O bond. Crabtree KN, Talipov MR, Martinez O, O'Connor GD, Khursan SL, McCarthy MC (2013) Detection and structure of HOON: microwave spectroscopy reveals an O-O bond exceeding 1.9 Å. Science 342(6164):13541357 doi: 10.1126/science.1244180

99 CAS RN: 7697-37-2 MGD RN: 578183 MW, IR, augmented by ab initio calculations

Nitric acid HNO3 Cs

O

HO

Bonds N=O(3) N=O(2) N–O(1) O(1)–H

r0 [Å] a 1.210(14) 1.199(13) 1.407(11) 0.957(23)

r (1) [Å] a m 1.2091(23) 1.1976(22) 1.4012(35) 0.9563(49)

Bond angles O(1)–N=O(3) O(1)–N=O(2) N–O(1)–H

θ0 [deg] a

[deg] a θ (1) m

115.9(9) 114.0(10) 102.3(12)

115.98(12) 114.07(45) 102.37(34)

r see [Å] a 1.2085(3) 1.1944(3) 1.3968(3) 0.9683(5)

N

O

θ see [deg] a

115.80(3) 114.15(2) 102.22(3)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

structures were determined from the previously published ground-state rotational constants of The r0 and r (1) m eight isotopic species. The semiexperimental structure r see was obtained by taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)_ae/cc-pVTZ harmonic and anharmonic (cubic) force fields. Gutle C, Demaison J, Rudolph HD (2009) Anharmonic force field and equilibrium structure of nitric acid. J Mol Spectrosc 254(2):99-107

2 Inorganic Molecules without Carbon Atoms

95

100 CAS RN: 14515-04-9 MGD RN: 139487 MW augmented by ab initio calculations Bonds H– N N=Si

r0 [Å] a 0.987(1) 1.554(1)

Iminosilylene Silicon imide HNSi C∞ v H

N

Si

r see [Å] a 0.9991(1) 1.5485(1)

Reprinted by permission of Taylor & Francis Ltd. Final version received 9 February 2015

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 43 GHz. The transient species was produced by an electrical discharge of silane with ammonia or molecular nitrogen. The r0 structure was determined from the ground-state rotational constants of seven isotopic species (main,29Si, 30 Si, 15N, D, 15N/D and 30Si/D); for the main isotopic species, the rotational transitions were also measured in excited vibrational states. The semiexperimental equilibrium structure was obtained by accounting for the rovibrational corrections calculated with the CCSD(T)/cc-pwCVQZ harmonic and anharmonic force fields. McCarthy MC, Tamassia F, Thorwirth S (2015) High-resolution rotational spectroscopy of iminosilylene, HNSi. Mol Phys 113(15-16):2204-2216

101 CAS RN: 1478687-85-2 MGD RN: 408981 MW supported by DFT calculations

Bonds Si(2)–N N=Si(1) Si(1)–H

r0 [Å] a 1.578(6) 1.705(6) 1.489(9)

Bond angles Si(1)=N–Si(2) H–Si(1)–N

θ0 [deg] a

(Silylidyneamino)silylidyne

Si H

HNSi2 Cs N Si

171.3(8) 105.4(6)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of (silylidyneamino)silylidyne was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 20 GHz. The transient species was produced by a discharge of silane, ammonia and nitrogen. The r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 15N, two 29Si, two 30Si and D).

96

2 Inorganic Molecules without Carbon Atoms

Crabtree KN, Martinez O, McCarthy MC (2013) Detection of two highly stable silicon nitrides: HSiNSi and H3SiNSi. J Phys Chem A 117(44):11282-11288

102 CAS RN: 7782-79-8 MGD RN: 964414 MW augmented by ab initio calculations

Hydrazoic acid Hydrogen azide HN3 Cs N

H

N N

a

Bonds H–N(1) N(1)=N(2) N(2)=N(3)

r0 [Å] 1.0222(41) 1.2453(89) 1.1346(91)

Bond angles H–N(1)=N(2) N(1)=N(2)=N(3)

θ0 [deg] a

109.58(39) 170.91(115)

rs [Å] 1.01488(23) 1.2293(14) 1.1463(14)

r see [Å] a 1.01577(16) 1.24174(37) 1.13066(38)

θs [deg] a

θ see [deg] a

a

108.995(32) 171.90(22)

109.133(17) 171.503(51)

Reproduced with permission of AIP Publishing. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of hydrazoic acid were recorded by a millimeter/submillimeter-wave free absorption spectrometer in the region between 235 and 450 GHz. The r0 and rs structures were determined from the ground-state rotational constants of fourteen isotopic species (main, D, three 15N, three 15N2, three 15N/D and three 15N2/D). The semiexperimental equilibrium structure r see was obtained taking into account the rovibrational corrections. The required cubic force constants were calculated by numerical differentiation of the analytic second derivatives from CCSD(T)/ANO2 computation. Amberger BK, Esselman BJ, Stanton JF, Woods RC, McMahon RJ (2015) Precise equilibrium structure determination of hydrazoic acid (HN3) by millimeter-wave spectroscopy. J Chem Phys 143(10):104310/1104310/9 [http://dx.doi.org/10.1063/1.4929792]

103 CAS RN: 71132-80-4 MGD RN: 148933 MW augmented by ab initio calculations

Hydroxysilylidyne HOSi Cs

O Si

Bonds Si–O O– H Bond angle H–O–Si

r0 [Å] a 1.648(2) 0.969(4)

θ0 [deg] 118.5 b

Reproduced with permission of AIP Publishing.

H

2 Inorganic Molecules without Carbon Atoms a b

97

Parenthesized uncertainties in units of the last significant digit. Constrained to the CCSD(T)/cc-pCVQZ value.

The rotational spectrum of hydroxysilylidyne (2Aꞌ electronic ground state) was investigated in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 43 GHz. The transient species was produced by a DC discharge of silane, water and oxygen. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 30 Si, 18O and D). McCarthy MC, Tamassia F, Woon DE, Thaddeus P (2008) A laboratory and theoretical study of silicon hydroxide SiOH. J Chem Phys 129(18):184301/1-184301/6 https://doi.org/10.1063/1.3002914

104 CAS RN: 85885-64-9 MGD RN: 359238 MW

Yttrium monohydroxide

Y

Bonds Y– O O– H

HOY C∞ v

O

H

r0 [Å] a 1.949(1) 0.921(1)

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of yttrium monohydroxide (1Σ+ electronic ground state) were recorded using Fourier transform microwave/millimeterwave techniques in the frequency region between 15 and 52 GHz. The transient compound was generated in a laser ablation source from yttrium vapor and water. The r0 structure was determined from the ground-state rotational constants of both isotopic species (main and D). The molecule was found to be linear. Halfen DT, Keogh JP, Ziurys LM (2015) The Fourier transform microwave/millimeter-wave spectrum of YOH and YOD (X1Σ+). J. Mol. Spectrosc. 314:79-82

105 CAS RN: 36011-55-9 MGD RN: 208553 MW

Zinc monohydroxide HOZn Cs O

Bonds Zn–O O– H

r0 [Å] a 1.809(5) 0.964(7)

Bond angle Zn–O–H

θ0 [deg] a 114.1(5)

[Å] a r (1) m 1.795(1) 0.967(3)

θ (1) [deg] a m 114.2(2)

Reprinted with permission. Copyright 2012 American Chemical Society.

Zn

H

98 a

2 Inorganic Molecules without Carbon Atoms

Parenthesized uncertainties in units of the last significant digit are 3σ values.

The rotational spectrum of zinc monohydroxide (2A' electronic ground state) was recorded by MW and millimeter-wave spectrometers in the frequency region between 22 and 482 GHz. Moreover, the spectrum of the title compound was obtained in a supersonic jet by a pulsed-nozzle Balle-Flygare type FTMW spectrometer. were determined from the ground-state rotational The r0 structure and the mass-dependent structure r (1) m constants of six isotopic species (main, D, 66Zn, 68Zn, 66Zn/D and 68Zn/D). Zack LN, Sun M, Bucchino MP, Clouthier DJ, Ziurys LM (2012) Gas-phase synthesis and structure of monomeric ZnOH: A model species for metalloenzymes and catalytic surfaces. J Phys Chem A 116(6):15421550

106 CAS RN: 12306-07-9 MGD RN: 340588 MW

Sulfur hydroxide oxide Hydroxyoxidosulfur HO2S Cs (assumed) S

Bonds H–O(1) O(1)–S S=O(2) Bond angles H–O(1)–S O(1)–S=O(2)

O

HO

a

r0 [Å] 0.950(10) 1.657(8) 1.442(8)

θ0 [deg] a 108.3(8) 108.8(1)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of hydroxyoxidosulfur radical were recorded in a supersonic jet by an FTMW spectrometer and a microwave-millimeter-wave double resonance spectrometer in the frequency region between 17 and 284 GHz. The transient species was produced in the gas phase by a DC glow discharge of hydrogen sulfide and oxygen. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 34S, 18 O2 and D). McCarthy MC, Lattanzi V, Martinez O, Gauss J, Thorwirth S (2013) Spectroscopic detection and structure of hydroxidooxidosulfur (HOSO) radical, an important intermediate in the chemistry of sulfur-bearing compounds. J Phys Chem Lett 4(23):4074-4079

107 CAS RN: 12500-78-6 MGD RN: 152368 MW augmented by ab initio calculation

Hydrotrioxy HO3 Cs O HO

Bonds

r0 [Å] a

r see [Å] b

O

2 Inorganic Molecules without Carbon Atoms

H–O(1) O(1)–O(2) O(2)–O(3)

0.913(26) 1.684(3) 1.235

0.944 1.660 1.225

Bond angles H–O(1)–O(2) O(1)–O(2)–O(3)

θ0 [deg] a

θ see [deg] b

92.4(14) 110.7(3)

99

95.3 110.3

Reproduced with permission of AIP Publishing [a].

a b

Parenthesized uncertainties in units of the last significant digit. Uncertainties were not given in the original paper.

The rotational spectra of the hydrotrioxy radical were investigated in a supersonic jet by FTMW spectroscopy and microwave-millimeter-wave double resonance techniques in the frequency region between 5 and 79 GHz. The radicals were produced by gas phase discharge of a mixture of oxygen and hydrogen. Three new isotopic species (H18OOO, HO18O18O , H18O18O18O) were investigated. The r0 structure was determined from the ground-state rotational constants of five isotopic species (together with previously published constants of the main and deuterated isotopic species). The semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections calculated with the CCSD(T)/aug-ccpVQZ harmonic and anharmonic (cubic) force fields. a. McCarthy MC, Lattanzi V, Kokkin D, Martinez O, Stanton JF (2012) On the molecular structure of HOOO. J Chem Phys 136(3):034303/1-034303/10 [doi:10.1063/1.3673875] MW

Bonds H–O(1) O(1)–O(2) O(2)–O(3) Bond angles H–O(1)–O(2) O(1)–O(2)–O(3)

r0 [Å] a 0.900(16) 1.684(7) 1.237(6)

θ0 [deg] a 91.5(8) 110.7(2)

Reprinted with permission. Copyright 2017 American Chemical Society [b].

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

In order to reanalyze the effective structure of the hydrotrioxy radical the rotational spectra of new 18O isotopic species were recorded by FTMW spectroscopy and microwave-millimeter-wave double resonance techniques. The rotational constants of six isotopic species (two 18O, D, 18O/d, 18O2/D and 18O3/D) were combined with the previously published rotational constants of the main and deuterated species to determine an improved effective structure r0. b. Barreau L, Martinez O, Crabtree KN, Womack CC, Stanton JF, McCarthy MC (2017) Oxygen-18 isotopic studies of HOOO and DOOO. J Phys Chem A 121(33):6296-6303

100

2 Inorganic Molecules without Carbon Atoms

108 CAS RN: 109306-51-6 MGD RN: 209328 MW augmented by ab initio calculations

Thioxophosphine HPS Cs

P H

Bonds H– P P =S

r0 [Å] a 1.444(5) 1.931(1)

Bond angle H–P=S

θ0 [deg] a 101.6(5)

r (1) [Å] a m 1.438(1) 1.9320(1)

S

r see [Å] a 1.4321(2) 1.9287(1)

θ (1) [deg] a θ see [deg] a m 101.85(9)

101.78(1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of thioxophosphine (1Aꞌ electronic ground state) were recorded in the MW, millimeterwave and submillimeter-wave regions between 15 and 419 GHz using a combination of molecular beam FTMW, millimeter direct absorption and microwave-microwave double resonance techniques. The transient species was produced by an AC discharge of phosphorous vapor with hydrogen sulfide. structures were determined from the ground-state rotational constants of three The r0 and mass-dependent r (1) m isotopic species (main, with 34S and D). The semiexperimental equilibrium structure was obtained by taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)/cc-pV(Q+d)Z harmonic and anharmonic (cubic) force fields. Halfen DT, Clouthier DJ, Ziurys LM, Lattanzi V, McCarthy MC, Thaddeus P, Thorwirth S (2011) The pure rotational spectrum of HPS (X1A'): Chemical bonding in second-row elements. J Chem Phys 134(13):134302/1134302/9 doi:10.1063/1.3562374

109 CAS RN: 95187-06-7 MGD RN: 211914 MW augmented by ab initio calculations

Phosphinidenesilylene Silylidynephosphine HPSi Cs H

P

Distances

a

H– P P=Si H...Si

r [Å] 1.488(4) 2.0454(1) 1.843(6)

Bond angle

θ see [deg]a

H–P=Si

se e

60.5(3)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

Si

2 Inorganic Molecules without Carbon Atoms

101

Rotational spectra were recorded by FTMW and millimeter wave spectrometers. The transient species was produced in the gas phase by a discharge of phosphine and silane. The semiexperimental r see structure was determined from the experimental ground-state rotational constants of two isotopic species (main and D) taking into account rovibrational corrections calculated with the CCSD(T)/ccpwCVQZ harmonic and anharmonic (cubic) force fields. This molecule with a bridged structure seems to be unique among SiP compounds. Lattanzi V, Thorwirth S, Halfen DT, Mück LA, Ziurys LM, Thaddeus P, Gauss J, McCarthy M. C (2010) Bonding in the heavy analogue of hydrogen cyanide: The curious case of bridged HPSi. Angew Chem 122(33):5795-5798; Angew Chem Int Ed 49(33):5661-5664

110 CAS RN: 1159216-34-8 MGD RN: 322779 MW

Zinc hydrogen sulfide HSZn Cs S

H

Zn

Bonds Zn–S S–H

r0 [Å] a 2.2194(6) 1.355(6)

r (1) [Å] a m 2.213(5) 1.351(3)

Bond angle

θ0 [deg] a

θ (1) [deg] a m

Zn–S–H

90.5(6)

90.6(1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

The rotational spectra of zinc hydrogen sulfide (2A' electronic ground state) were studied both by supersonic FTMW spectroscopy and by millimeter-wave direct absorption spectroscopy in the frequency region between 18 and 468 GHz. The transient species was produced by a DC discharge of zinc vapor with hydrogen sulfide. mass-dependent structures were determined from the ground-state rotational constants of four The r0 and r (1) m isotopic species (main, 66Zn, 68Zn and D). Bucchino MP, Adande GR, Halfen DT, Ziurys LM (2017) Examining transition metal hydrosulfides: The pure rotational spectrum of ZnSH (X2A'). J Chem Phys 147(15):154313/1-154313/9 https://doi.org/10.1063/1.4999924

111 CAS RN: 15612-85-8 MGD RN: 144971 MW

Hydrogen iodide dimer H2I2 C2h H

Distance Rcm c

r0 [Å] a,b 4.56372(1)

Angle H–I…I

θ0 [deg] a,b 46.405(1)

Copyright 2009 with permission from Elsevier.

I

2

102

2 Inorganic Molecules without Carbon Atoms

a

Parenthesized uncertainty in units of the last significant digit. See text for the significance of the structure. c Distance between the centers of mass of the monomer subunits. b

The rotational-vibrational spectrum of the HI dimer in the geared bending mode ν5 was recorded by a pulsed-jet submillimeter spectrometer at 511.9 GHz. The ground state structure was determined using a theoretical approach accounting for the large amplitude motion effects and hyperfine matrix elements within and between vibrational states. Coudert LH, Belov SP, Willaert F, McElmurry BA, Bevan JW, Hougen JT (2009) Submillimeter spectrum and analysis of vibrational and hyperfine coupling effects in (HI)2. Chem Phys Lett 482(4-6):180-188

112 CAS RN: 13760-02-6 MGD RN: 152123 MW

Diiodosilane H2I2Si C2v H

Bonds Si–I Si–H

r0 [Å] a 2.4236(19) 1.475(21)

Bond angles I–Si–I H–Si–H

θ0 [deg] a

H

Si I

I

111.27(13) 105.9(19)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of diiodosilane were recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 8.8 and 15 GHz. The r0 structure was determined from the ground-state rotational constants of three isotopic species (main, 29Si and 30Si). Arsenault EA, Obenchain DA, Orellana W, Novick SE (2017) Nuclear quadrupole coupling in SiH2I2 due to the presence of two iodine nuclei. J Mol Spectrosc 338(2):72-76

113 CAS RN: 560070-23-7 MGD RN: 211533 IR supported by ab initio calculations

(Dihydrogen-κH,κH')magnesium (1+) ion Magnesium (1+) ion – dihydrogen (1/1) H2Mg C2v H Mg

Distance Rcm b

r0 [Å] a 2.716

Reprinted with permission. Copyright 2009 American Chemical Society.

H

2 Inorganic Molecules without Carbon Atoms a b

103

Uncertainty was not given in the original paper. Distance between Mg+ and the center of the H–H bond.

The rotationally resolved IR spectra of the binary complex of the magnesium ion with dihydrogen and dideuterium were recorded in the H–H stretching region (4025-4080 cm-1) and the D–D stretching region (28952945 cm-1), respectively, by monitoring the Mg+ photofragments. The partial r0 structure of each isotopic species was determined under the assumption that the hydrogen-hydrogen distance was not changed upon complexation. The intermolecular distance was found to be shortened significantly upon deuteration. Dryza V, Poad BLJ, Bieske EJ (2009) Infrared spectra of mass-selected Mg+-H2 and Mg+-D2 complexes. J Phys Chem A 113(1):199-204

114 CAS RN: 189063-60-3 MGD RN: 211324 IR supported by DFT calculations

(Dihydrogen-κH,κH')manganese (1+) ion Manganese (1+) ion – dihydrogen (1/1) H2Mn C2v H

Distance Rcm b

Mn

r0 [Å] a 2.73

H

Reprinted with permission. Copyright 2009 American Chemical Society.

a b

Uncertainty was not given in the original paper. Distance between Mn+ and the center of the H–H bond.

The rotationally resolved IR spectrum of the binary complex of the manganese ion with dihydrogen was recorded in the H–H stretching region (4022-4078 cm-1) by monitoring the Mg+ photofragments. The partial r0 structure of the T-shaped configuration was determined assuming that the H–H distance was not changed upon complexation. Dryza V, Poad BLJ, Bieske EJ (2009) Spectroscopic study of the benchmark Mn+-H2 complex. J Phys Chem A 113(21):6044-6048

115 CAS RN: 35576-91-1 MGD RN: 471122 MW supported by ab initio calculations

Nitrosamine Nitrosamide H2N2O Cs (assumed) N H 2N

Bonds N(1)–H(1) N(1)–H(2) N(1)–N(2) N(2)=O Bond angles N(1)–N(2)=O

r0 [Å] a 1.010(3) 0.991(4) 1.342(3) 1.217(3)

θ0 [deg] a

113.67(5)

O

104

2 Inorganic Molecules without Carbon Atoms

N(2)–N(1)–H(1) N(2)–N(1)–H(2)

117.5(3) 116.3(4)

Dihedral angle H(1)–N(1)–N(2)=O

τ0 [deg] 0

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of nitrosamine were recorded by a molecular beam Balle-Flygare type FTMW spectrometer and by millimeter-wave/microwave double resonance techniques in the frequency region between 5 and 91 GHz. The transient species were produced by a gas discharge of ammonia with oxygen. The r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, two 15 N, 18O, two D and D2). McCarthy MC, Lee KLK, Stanton JF (2017) Detection and structural characterization of nitrosamide H2NNO: A central intermediate in deNOx processes. J Chem Phys 147(13):134301/1-134301/9 https://doi.org/10.1063/1.4992097

116 CAS RN: 71356-61-1 MGD RN: 119821 IR

Water – dinitrogen (1/1) H2N2O Cs O

Distance Rcm b

r0 [Å] a 3.8309

H

H

N

N

Reproduced with permission of AIP Publishing. a b

Uncertainty was not given in the original paper. Distance between centers of mass in both monomer subunits.

The rotationally resolved IR spectrum of the binary van der Waals complex of perdeuterated water with dinitrogen was recorded in a supersonic jet by a tunable diode laser spectrometer in the region of the ν2 bending fundamental of D2O. The partial r0 structure was determined under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Zhu Y, Zheng R, Li S, Yang Y, Duan C (2013) Infrared spectra and tunneling dynamics of the N2-D2O and OCD2O complexes in the ν2 bend region of D2O. J Chem Phys 139(21):214309/1-214309/6 [http://dx.doi.org/10.1063/1.4836616]

117 CAS RN: 935668-06-7 MGD RN: 211871 IR

Distance Rcm b

r0 [Å] a 2.461

Sodium (1+) ion – dihydrogen (1/1) H2Na C2v H Na H

+

2 Inorganic Molecules without Carbon Atoms

105

Reproduced with permission of AIP Publishing.

a b

Uncertainty was not given in the original paper. Distance between Na+ and the midpoint of D–D.

The rotationally resolved IR spectrum of the binary complex of the sodium ion with dideuterium was recorded in the D–D stretching region between 2915 and 2972 cm-1 detecting Na+ photofragments. The partial r0 structure was determined under the assumption that the D–D bond distance did not change upon complexation. Poad BLJ, Dryza V, Kłos J, Buchachenko AA, Bieske EJ (2011) Rotationally resolved infrared spectrum of the Na+-D2 complex: An experimental and theoretical study. J Chem Phys 134(21):214302/1-214302/6 doi:10.1063/1.3596720

118 CAS RN: 16300-71-3 MGD RN: 745402 IR

Dihydrogen – neon (1/1) H2Ne C2v H

Distance Rcm b

H

Ne

r0 [Å] a 4.031

Republished with permission of Canadian Science Publishing. Permission conveyed through Copyright Clearance Center, Inc. a b

Uncertainty was not given in the original paper. Distance between Ne and the center-of-mass of H2.

The partial r0 structure of the title complex was redetermined from the previously published ground-state rotational constants assuming that H–H distance was not changed upon complexation. McKellar ARW (2013) High resolution infrared spectra of H2-Xe and D2-Xe van der Waals complexes. Can J Phys 91(11):957-962

119 CAS RN: 213474-04-5 MGD RN: 215704 IR

Water – neon (1/1) H2NeO (see comment) O

Distance Rcm b

a

r0 [Å] 3.5203

Reproduced with permission of AIP Publishing. a b

Uncertainty was not given in the original paper. Distance between Ne and the center-of-mass of the water subunit.

H

H

Ne

106

2 Inorganic Molecules without Carbon Atoms

The rotationally resolved IR spectrum of the binary van der Waals complex of perdeuterated water with neon was recorded in a supersonic jet by a diode laser spectrometer in the D2O bending region at about 1200 cm-1. The van der Waals bond length was determined in pseudodiatomic approximation. Li S, Zheng R, Zhu Y, Duan C (2011) Infrared diode laser spectroscopy of the Ne-D2O van der Waals complex: Strong Coriolis and angular-radial coupling. J Chem Phys 135(13):134304/1-134304/7 doi:10.1063/1.3644776

120 CAS RN: 127506-55-2 MGD RN: 147752 MW supported by ab initio calculations

Hydrogen thioperoxide Sulfenic acid H2OS C1 H

S H

Bonds S–O S–H O– H

re [Å] a 1.669514(30) 1.3414 0.9601

Bond angles H–S–O H– O– S

θe [deg] a

Dihedral angle H–O–S–H

O

97.1784(17) 107.01

τe [deg] a

84.659(21)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainty in units of the last significant digit.

An equilibrium structure re was determined by a generalized semi-rigid bender treatment of the previously published torsion-rotational spectra. Ross SC, Yamada KMT, Ito F (2010) Torsion-rotation coupling and the determination of the torsional potential energy function of HSOH. Phys Chem Chem Phys 12(36):11133-11150

121 CAS RN: 112548-30-8 MGD RN: 474831 MW augmented by ab initio calculations Bonds H(1)–O(1) O(1)–Si Si–O(2) O(2)–H(2) Bond angles

Dihydroxysilylene H2O2Si Cs Si a

a

r0 [Å] 0.973(26) 1.639(9) 1.657(10) 0.920(62)

r [Å] 0.960(3) 1.635(1) 1.654(1) 0.946(8)

θ0 [deg] a

θ see [deg] a

se e

HO

OH

2 Inorganic Molecules without Carbon Atoms

H(1)–O(1)–Si O(1)–Si–O(2) Si–O(2)–H(2)

117(2) 100.2(2) 120(10)

107

117.7(1) 99.59(5) 117(1)

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of dihydroxysilylene were recorded in a supersonic jet by an FTMW spectrometer and by MW double resonance techniques in the frequency region between 6.5 and 34 GHz. The transient species was produced by a gas phase electrical discharge of a mixture of silane with oxygen. Only the syn-anti conformer was observed. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, two 18 O and 30Si). The semiexperimental equilibrium structure r see was obtained from the experimental rotational constants taking into account rovibrational corrections calculated with the CCSD(T)/cc-pVTZ harmonic and anharmonic force fields. McCarthy MC, Gauss J (2016) Exotic SiO2H2 isomers: Theory and experiment working in harmony. J Phys Chem Lett 7(10):1895-1900

122 CAS RN:121271-09-8 MGD RN: 475016 MW augmented by ab initio calculations

Dioxasilacyclopropane Siladioxirane H2O2Si C2v O

Bonds Si–O Si–H

r0 [Å] a 1.642(1) 1.462(1)

r see [Å] a 1.6373(5) 1.4641(5)

Bond angles O–Si–O H–Si–H

θ0 [deg] a

θ see [deg] a

59.1(3) 113.0(7)

O

SiH2

58.94(10) 113.24(14)

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of siladioxirane were recorded in a supersonic jet by an FTMW spectrometer and by MW double resonance techniques in the frequency region between 6.5 and 34 GHz. The transient species was produced by a gas phase electrical discharge of a mixture of silane with oxygen. The r0 structure was determined from the ground-state rotational constants of six isotopic species (main, D2, 29Si, 30 Si, 18O and 18O2). The semiexperimental equilibrium structure r see was obtained from the experimental rotational constants taking into account rovibrational corrections calculated with the CCSD(T)/cc-pVTZ harmonic and aharmonic (cubic) force fields. McCarthy MC, Gauss J (2016) Exotic SiO2H2 isomers: Theory and experiment working in harmony. J Phys Chem Lett 7(10):1895-1900

108

2 Inorganic Molecules without Carbon Atoms

123 CAS RN: 69639-29-8 MGD RN: 211270 MW augmented by ab initio calculations

Thioxosilane Silanethione H2SSi C2v S

Bonds S=Si Si–H

r0 [Å] a 1.9397 1.4837

r see [Å] a 1.9357 1.4734

Bond angle H–Si–H

θ0 [deg] a

θ see [deg] a

111.64

Si H

H

110.32

Reproduced with permission of AIP Publishing.

a

Uncertainties were not given in the original paper.

The rotational spectra of silanethione were recorded by FTMW spectrometer in the frequency region between 5 and 43 GHz; several lines were also observed in the millimeter band up to 377 GHz. The transient species was produced by a low-current DC discharge of silane and hydrogen sulfide. The r0 structure was determined from the ground state rotational constants of ten isotopic species (main, 29Si, 30 Si, 33S, 34S, D, D2, 29Si/D2, 30Si/D2 and 34S/D2). The semiexperimental equilibrium structure r see was obtained taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)/cc-pV(Q+d)Z harmonic and anharmonic (cubic) force fields. McCarthy MC, Gottlieb CA, Thaddeus P, Thorwirth S, Gauss J (2011) Rotational spectra and equilibrium structures of H2SiS and Si2S. J Chem Phys 134(3):034306/1-034306/10 doi:10.1063/1.3510732

124 CAS RN: 13825-90-6 MGD RN: 360354 UV

Silylene

Si

Bond Si–H

re [Å] a 1.5137(3)

Bond angle

θe [deg] a

H–Si–H

H

H2Si C2v H

92.04(5)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainty in units of the last significant digit is 1σ value.

The rotationally resolved optical spectra of the mono-deuterated silylene were recorded in a supersonic jet. The transient species was produced by a pulsed DC discharge. The ground-state rotational constants were combined with those of SiH2 and SiD2 to improve the equilibrium structure re.

2 Inorganic Molecules without Carbon Atoms

109

Kokkin DL, Ma T, Steimle T, Sears TJ (2016) Detection and characterization of singly deuterated silylene, SiHD, via optical spectroscopy. J Chem Phys. 144(24):244304/1-244304/13 [http://dx.doi.org/10.1063/1.4954702]

125 CAS RN: 12593-17-8 MGD RN: 128393 IR

Dihydrogen – xenon (1/1) H2Xe C2v H

Distance Rcm b

r0 [Å] 4.245

H

Xe

a

Republished with permission of Canadian Science Publishing. Permission conveyed through Copyright Clearance Center, Inc.

a b

Uncertainty was not given in the original paper. Distance between Xe and the center-of-mass of H2.

The rotationally resolved vibrational spectra of the binary van der Waals complex of dihydrogen and dideuterium with xenon were recorded in a multi-pass absorption cell by a high-resolution FTIR spectrometer in the spectral regions of the H2 and D2 fundamental stretching at about 4155 and 3166 cm-1, respectively. The partial r0 structure was determined from the ground-state rotational constants assuming that H–H distance was not changed upon complexation. McKellar ARW (2013) High resolution infrared spectra of H2-Xe and D2-Xe van der Waals complexes. Can J Phys 91(11):957-962

126 CAS RN: 189063-66-9 MGD RN: 211140 IR supported by DFT calculations

(Dihydrogen-κH,κH')zinc (1+) ion Zinc (1+) ion – dihydrogen (1/1) H2Zn C2v H

Distance Rcm b

r0 [Å] 2.32

Zn

a

+

H

Reproduced with permission of AIP Publishing. a b

Uncertainty was not given in the original paper. Distance between Zn+ and the midpoint of D-D.

The rotationally resolved IR spectrum of the binary van der Waals complex of the zinc ion with dideuterium was recorded in a supersonic jet in the region of the D–D stretching fundamental between 2815 and 2866 cm-1 by detecting Zn+ photofragments. The ionic complex was produced by passing deuterium over a laser-ablated zinc rod. The partial r0 structure was determined from the ground-state rotational constants of the ZnD2 isotopic species under the assumption that the D–D distance was not changed upon complexation. The molecule was found to have a T-shaped structure.

110

2 Inorganic Molecules without Carbon Atoms

Dryza V, Bieske EJ (2009) Structure and properties of the Zn+-D2 complex. J Chem Phys 131(22):224304/1224304/7 doi:10.1063/1.3266935

127 CAS RN: 167413-01-6 MGD RN: 408803 MW augmented by DFT calculations

(Silylimino)silylene H3NSi2 C3v H H

Bonds Si(2)=N N–Si(1) Si(1)–H

r0 [Å] a 1.560(7) 1.712(7) 1.487 b

Bond angles Si(1)–N=Si(2) H–Si(1)–N

θ0 [deg] a

Si

N

Si

H

180.0 c 109.99(6)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized estimated uncertainties in units of the last significant digit. Constrained to the value from UB3LYP/6-311++G(d,p) calculation. c By symmetry. b

The rotational spectrum of (silylimino)silylene was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 20 GHz. The transient species was produced by a discharge of silane, ammonia and nitrogen. The r0 structure was determined from the ground-state rotational constants of five isotopic species (main, two 29 Si, 15N and D3). Crabtree KN, Martinez O, McCarthy MC (2013) Detection of two highly stable silicon nitrides: HSiNSi and H3SiNSi. J Phys Chem A 117(44):11282-11288

128 CAS RN: 18155-21-0 MGD RN: 310283 MW augmented by ab initio calculations

Bond S–H

r see [Å] a 1.349872(13)

Bond angle

θ see [deg] a

H–S–H

94.1405(26)

Copyright 2009 with permission from Elsevier.

Sulfonium

H

H3S C3v

S

H

H

2 Inorganic Molecules without Carbon Atoms a

111

Uncertainty given in in parentheses in units of the last significant digit corresponds to 99% confidence interval.

The rotational spectrum of the ions produced by a magnetically confined negative glow discharge was recorded by a submillimeter-wave source-modulated spectrometer in the frequency region between 324 and 637 GHz. The semiexperimental equilibrium structure, r see , was obtained from ten accurate experimental ground-state rotational constants of six isotopic species (main, 34S, D, D2 and D3), by taking into account the rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)/cc-pwCVQZ harmonic and anharmonic force fields. Dore L, Bizzocchi L, Degli Esposti C (2009) Millimeter-wave spectroscopy of deuterated hydrogen sulfide, SH2D+. J Mol Spectrosc 254(1):33-38.

129 CAS RN: 182628-51-9 MGD RN: 141391 MW

Si–O…X

H6OSi Cs H

rs [Å] a 3.318

Distance Si…O Angles

Silane – water (1/1)

b

H

O

Si H

H

H

H

θs [deg] a 135

Reproduced with permission of AIP Publishing.

a b

Uncertainty was not given in the original paper. X is the midpoint of the H–H distance in the water subunit.

The rotational spectra of the binary complex of silane with water were recorded in a supersonic jet by a pulsednozzle Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 22 GHz. The partial rs structure was determined from the ground-state rotational constants of thirteen isotopic species (main, 29Si, 30Si, 18O, D, D2, D4, D5, D6, 29Si/D, 29Si/D2, 30Si/D and 30Si/D2). As a result the complex exhibits a threefold internal rotation of the silane subunit about one of its Si–H bonds, whereas the symmetry axis of the water subunit is bent away from its internal rotation axis. Kawashima Y, Suenram RD, Hirota E (2016) Microwave spectra of the SiH4-H2O complex: A new sort of intermolecular interaction. J Chem Phys 145(11):114307/1-114307/18 [http://dx.doi.org/10.1063/1.4962363]

Hexacyclo[9.9.13,9.15,17.17,15.113,19]decasiloxane Decasilsesquioxane H10O15Si10 D5h

130 CAS RN: 281-49-2 MGD RN: 362102 GED augmented by QC computations

HSi HSi

Bonds Si(2)–O(2) Si(3)–O(6) Si–H

O

SiH

O

re,MD [Å] a 1.616(2) b 1.622(3) b 1.457(7) c

O

O O O

HSi

O

O

SiH O SiH

O

O HSi

H Si

O

Si H

O

O O

SiH

112

Angles Si(2)–O(2)–Si(3) Si(3)–O(6)–Si(9) X…A…O d X…Si–H d

2 Inorganic Molecules without Carbon Atoms

θe,MD [deg] a 155.0(5) 153.9(7) 103.1(5)e 148.5(9) e

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. b Difference between the Si–O bond lengths was restrained to the value from MP2/6-311++G(3df,3pd) computation. c Restrained to the value derived from the published IR data. d X is the centre of the pentagon formed by five Si atoms. A is the midpoint between two adjacent Si atoms on the five-side face. e Restrained to the value from computation as indicated above. The GED experiment was carried out at Tnozzle of 423 and 453 K at the long and short nozzle-to-film distances, respectively. Vibrational corrections to experimental internuclear distances, ∆re,MD = ra − re,MD, were derived from the CarParrinello MD simulations. The ten-membered silicon-oxygen rings were found to be very flexible. Wann DA, Rataboul F, Reilly AM, Robertson HE, Lickiss PD, Rankin DWH (2009) The gas-phase structure of the decasilsesquioxane Si10O15H10. Dalton Trans 34:6843-684

131 CAS RN: 139322-38-6 MGD RN: 139309 MW supported by ab initio calculations

Distances O(1)...O(2) O(2)...O(3) O(3)...O(4) O(4)...O(1) O(5)...O(1) O(5)...O(3) O(6)...O(2) O(6)...O(4)

Distances O(1)...O(2) O(2)...O(3) O(1)...O(3) O(4)...O(5) O(5)...O(6) O(4)...O(6) O(1)...O(5) O(2)...O(6) O(3)...O(4)

Water hexamer H12O6 C1 (cage) C1 (prism) C1 (book) O

cage r0 [Å] a 2.960(10) 2.709(11) 3.014(10) 2.977(10) 2.752(10) 2.787(9) 2.820(9) 2.794(11)

rs [Å] 2.943(4) 2.686(4) 2.989(5) 2.945(4) 2.712(32) 2.822(31) 2.816(58) 2.809(59)

prism r0 [Å] a 2.829(7) 2.985(7) 2.984(7) 2.932(7) 2.809(7) 2.992(7) 2.696(8) 2.963(7) 2.785(8)

rs [Å] a 2.822(3) 2.996(14) 2.923(15) 2.890(50) 2.793(3) 2.980(45) 2.680(4) 2.963(3) 2.772(3)

a

H

H

6

2 Inorganic Molecules without Carbon Atoms

Distances O(1)...O(2) O(2)...O(3) O(5)...O(6) O(4)...O(6) O(1)...O(5) O(2)...O(6) O(3)...O(4)

book r0 [Å] a 2.726(11) 2.828(11) 2.723(10) 2.816(9) 2.728(7) 2.979(6) 2.813(7)

113

rs [Å] a 2.680(218) 2.868(223) 2.834(61) 2.687(61) 2.717(2) 2.960(2) 2.801(2)

Reprinted with permission from AAAS. a

cage Parenthesized uncertainties in units of the last significant digit are 1σ values.

prism

book

The rotational spectra of the water hexamer were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18 GHz. Three conformers, characterized by the cage-, prism- and book-shaped form, were detected. The partial r0 structure of the oxygen framework of each conformer was determined from the ground-state rotational constants of seven isotopic species (main and six 18O) assuming that the structures of the water subunits were not changed upon complexation. The partial rs structures were also obtained. Pérez C, Muckle MT, Zaleski DP, Seifert NA, Temelso B, Shields GC, Kisiel Z, Pate BH (2012) Structures of cage, prism, and book isomers of water hexamer from broadband rotational spectroscopy. Science 336(6083):897-901 doi: 10.1126/science.1220574

132 CAS RN: 144442-58-0 MGD RN: 352342 MW supported by ab initio calculations

Water heptamer H14O7 C1 O H

Distances O(1)…O(7) O(3)…O(7) O(1)…O(3) O(2)…O(4) O(4)…O(5) O(5)…O(6) O(2)…O(6) O(1)…O(2)

r0 [Å] a 2.799(8) 2.886(13) 3.009(10) 2.947(12) 2.923(10) 2.795(11) 2.765(11) 2.920(11)

rs [Å] a 2.787(2) 2.880(4) 2.996(2) 2.936(5) 2.898(4) 2.793(4) 2.757(5) 2.906(3)

r (1) [Å] a m 2.770(3) 2.872(3) 2.985(2) 2.924(3) 2.883(3) 2.786(2) 2.746(2) 2.890(3)

H

7

114

O(3)…O(4) O(5)…O(7)

2 Inorganic Molecules without Carbon Atoms

2.754(12) 2.683(10)

2.741(6) 2.657(2)

2.730(2) 2.648(3)

Copyright 2013 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the water heptamer was recorded in a supersonic jet by a chirped-pulsed FTMW spectrometer in the spectral range between 2 and 18 GHz. structures of the O atom framework were The r0, rs and r (1) m determined from the ground-state rotational constants of the main and seven singly substituted 18O isotopic species. Pérez C, Lobsiger S, Seifert NA, Zaleski DP, Temelso B, Shields GC, Kisiel Z, Pate BH (2013) Broadband Fourier transform rotational spectroscopy for structure determination: The water heptamer. Chem Phys Lett 571:1-15 133 CAS RN: 144442-59-1 MGD RN: 352170 MW augmented by ab initio calculations

Water nonamer H18O9 C1 (see comment) O H

Distances O(2)...O(1) O(3)...O(1) O(4)...O(3) O(6)...O(4) O(9)...O(7) O(8)...O(9)

D1 rs [Å]a 2.90(8) 2.86(9) 2.90(8) 2.68(1) 2.71(1)

H

9

r (1) [Å]a m 2.867(7) 2.877(6) 4.029(12) 2.876(7) 2.682(7)

Angles O(3)...O(1)...O(2) O(4)...O(3)...O(2) O(5)...O(4)...O(3) O(6)...O(4)...O(2) O(7)...O(6)...O(4) O(8)...O(2)...O(1) O(9)...O(7)...O(6)

[deg] a θ (1) m

Dihedral angles O(4)...O(3)...O(2)...O(1) O(5)...O(4)...O(3)...O(2) O(6)...O(4)...O(2)...O(1) O(7)...O(6)...O(4)...O(1) O(8)...O(2)...O(1)...O(3) O(9)...O(7)...O(6)...O(4)

[deg] a τ (1) m

92.68(13) 58.94(23) 41.65(20) 41.67(19) 97.47(17) 85.68(18) 101.63(51)

-50.73(18) -116.96(47) 170.55(69) -103.87(34) 12.86(16) 117.07(60)

D1

2 Inorganic Molecules without Carbon Atoms

Distances O(2)...O(1) O(3)...O(1) O(4)...O(3) O(6)...O(4) O(9)...O(7) O(8)...O(9)

S1 rs [Å] a 2.85(7) 2.85(7) 2.92(8) 2.77(1) 2.83(1)

r (1) [Å] a m 2.852(8) 2.870(9) 4.098(15) 2.907(9) 2.818(8)

Angles O(3)...O(1)...O(2) O(4)...O(3)...O(2) O(5)...O(4)...O(3) O(6)...O(4)...O(2) O(7)...O(6)...O(4) O(8)...O(2)...O(1) O(9)...O(7)...O(6)

[deg] a θ (1) m

Dihedral angles O(4)...O(3)...O(2)...O(1) O(5)...O(4)...O(3)...O(2) O(6)...O(4)...O(2)...O(1) O(7)...O(6)...O(4)...O(1) O(8)...O(2)...O(1)...O(3) O(9)...O(7)...O(6)...O(4)

[deg] a τ (1) m

Distances O(2)...O(1) O(3)...O(1) O(4)...O(3) O(6)...O(4) O(9)...O(7) O(8)...O(9)

91.19(16) 59.43(30) 43.76(24) 41.46(25) 93.12(21) 83.91(23) 97.20(65)

S2 rs [Å]a 2.68(9) 2.68(9) 2.64(9) 2.71(1) 2.69(1)

115

S1

-48.87(23) -117.40(61) 170.96(94) -105.23(45) 10.94(19) 122.09(68)

r (1) [Å]a m 2.681(5) 2.873(5) 3.827(10) 2.686(6) 2.694(4)

Angles O(3)...O(1)...O(2) O(4)...O(3)...O(2) O(5)...O(4)...O(3) O(6)...O(4)...O(2) O(7)...O(6)...O(4) O(8)...O(2)...O(1) O(9)...O(7)...O(6)

θ (1) [deg] a m

Dihedral angles O(4)...O(3)...O(2)...O(1) O(5)...O(4)...O(3) O(2) O(6)...O(4)...O(2)...O(1) O(7)...O(6)...O(4)...O(1) O(8)...O(2)...O(1)...O(3) O(9)...O(7)...O(6)...O(4)

τ (1) [deg] a m

83.21(9) 60.65(22) 44.26(13) 48.64(13) 88.37(14) 97.71(14) 111.36(43)

-58.42(14) -129.80(38) -170.43(49) -102.28(21) 18.83(13) 118.16(44)

Copyright Wiley...VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

S2

116 a

2 Inorganic Molecules without Carbon Atoms

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the water nonamer was recorded by a chirped-pulse FTMW spectrometer in the frequency range between 2 and 8 GHz. The observed conformers, D1, S1 and S2, are the lowest energy clusters predicted by RI-MP2/CBS calculations. They are closely related to the S4 and D2d structures of the water octamer and have the same O atom skeleton with a pentamer ring stacked on a tetramer ring. The partial structures of D1, S1 and S2 conformers were determined from the ground-state rotational constants of the main species, as well as seven, nine and nine 18O isotopic species, respectively. Pérez C, Zaleski DP, Seifert NA, Temelso B, Shields GC, Kisiel Z, Pate BH (2014) Hydrogen bond cooperativity and the three-dimensional structures of water nonamers and decamers. Angew Chem 126(52):14596-14600; Angew Chem Int Ed. 53(52):14368-14372

134 CAS RN: 142473-62-9 MGD RN: 410651 MW augmented by ab initio calculations

Water decamer H20O10 C1 (see comment) O H

Distances O(2)...O(1) O(3)...O(2) O(4)...O(3) O(5)...O(1) O(6)...O(1) O(7)...O(2) O(8)...O(3) O(9)...O(4) O(10)...O(5) O(8)...O(7) O(9)...O(8) O(9)...O(10)

PPD1 rs [Å]a 2.68(1) 2.84(1) 2.72(2) 2.85(1) 2.84(1) 2.68(1) 2.84(1) 2.75(2) 2.83(1) 2.61(2) 2.83(2)

Angles O(3)...O(1)...O(2) O(4)...O(3)...O(2) O(5)...O(1)...O(2) O(6)...O(1)...O(4) O(7)...O(2)...O(3) O(8)...O(3)...O(4) O(9)...O(4)...O(3) O(10)...O(5)...O(1) Dihedral angles O(4)...O(3)...O(2)...O(1) O(5)...O(1)...O(2)...O(3) O(6)...O(1)...O(4)...O(3) O(7)...O(2)...O(3)...O(4) O(8)...O(3)...O(4)...O(2) O(9)...O(4)...O(3)...O(5)

r (1) [Å]a m 2.682(9) 2.844(6) 2.651(9) 2.857(7) 2.833(8) 2.870(9) 2.834(8) 2.938(7) 2.928(8)

θ (1) [deg] a m

111.37(13) 105.53(16) 104.37(10) 84.35(6) 95.91(13) 85.38(12) 94.67(32) 96.58(15)

τ (1) [deg] a m 10.81(23) -9.57(22) 94.68(15) -85.36(17) -82.17(13) 93.10(25)

H

10

2 Inorganic Molecules without Carbon Atoms

O(10)...O(5)...O(1)...O(2)

Distances O(2)...O(1) O(3)...O(2) O(4)...O(3) O(5)...O(1) O(6)...O(1) O(7)...O(2) O(8)...O(3) O(9)...O(4) O(10)...O(5) O(8)...O(7) O(9)...O(8) O(9)...O(10)

PPS1 rs [Å]a 2.77(10) 2.89(10) 2.67(1) 2.89(1) 2.75(13) 2.89(10) 2.53(12) 2.76(2) 2.53(12) 2.89(2) 2.83(2)

117

-84.81(17)

r (1) [Å]a m 2.673(35) 2.850(32) 2.650(18) 2.876(19) 2.871(27) 2.896(27) 2.886(29) 2.918(29) 2.957(27)

Angles O(3)...O(1)...O(2) O(4)...O(3)...O(2) O(5)...O(1)...O(2) O(6)...O(1)...O(4) O(7)...O(2)...O(3) O(8)...O(3)...O(4) O(9)...O(4)...O(3) O(10)...O(5)...O(1)

θ (1) [deg] a m

Dihedral angles O(4)...O(3)...O(2)...O(1) O(5)...O(1)...O(2)...O(3) O(6)...O(1)...O(4)...O(3) O(7)...O(2)...O(3)...O(4) O(8)...O(3)...O(4)...O(2) O(9)...O(4)...O(3)...O(5) O(10)...O(5)...O(1)...O(2)

τ (1) [deg] a m

111.57(46) 105.29(47) 104.44(51) 83.35(37) 93.36(96) 85.62(49) 98.45(61) 92.97(64)

11.42(89) -10.58(84) 95.91(84) -87.18(79) -80.91(51) 91.15(58) -86.87(72)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

PPD1

PPS1

118

2 Inorganic Molecules without Carbon Atoms

The rotational spectrum of the water decamer was recorded by a chirped-pulse FTMW spectrometer in the frequency range between 2 and 8 GHz. The observed conformers, PPD1 and PPS1, are the lowest energy clusters predicted by RI-MP2/CBS calculations. They are closely related to the S4 and D2d structures of the water octamer. Both conformers have a similar O atom skeleton with two stacked pentamer rings and different orientation of the H-bonding network. The partial structures of PPD1 and PPS1 conformers were determined from the ground-state rotational constants of the main species, as well as ten and nine 18O isotopic species, respectively. Pérez C, Zaleski DP, Seifert NA, Temelso B, Shields GC, Kisiel Z, Pate BH (2014) Hydrogen bond cooperativity and the three-dimensional structures of water nonamers and decamers. Angew Chem 126(52):14596-14600; Angew Chem Int Ed. 53(52):14368-14372.

135 CAS RN: 491846-53-8 MGD RN: 150511 IR

Dinitrogen monoxide – helium (1/1) HeN2O Cs N

Distance Rcm b

r0 [Å] 3.3926

Angle

θ0 [deg] a

ϕ

c

N

O

He

a

84.549

Copyright 2009 with permission from Elsevier.

a

Uncertainty was not given in the original paper. Distance between He and the center-of-mass of the N2O subunit. c Angle between Rcm and the NNO axis. b

The rotationally resolved vibrational spectrum of the binary van der Waals complex was recorded in the N2O monomer ν1 fundamental region at 1285 cm-1 using an IR tunable diode laser spectrometer in conjunction with a free supersonic-jet expansion and an astigmatic multi-pass absorption cell. The partial r0 structure was determined from the ground-state rotational constants under the assumption that the structure of the N2O subunit was not changed upon complexation. Zhu D, Wang R, Zheng R, Huang G, Duan C (2009) Infrared diode laser spectroscopy of the He-N2O van der Waals complex in the 1285 cm-1 region. J Mol Spectrosc 253(2):88-91

136 CAS RN: 13813-41-7 MGD RN: 146602 GED combined with MS and augmented by QC computations

Bond Ho–I

rg [Å] a 2.800(6)

Holmium(III) iodide Holmium triiodide HoI3 D3h (see comment) HoI3

2 Inorganic Molecules without Carbon Atoms

Bond angle I–Ho–I

119

θg [deg] a

116.7(10)

Copyright 2010 with permission from Elsevier. a

Parenthesized uncertainty in units of the last significant digit is estimated total error.

The combined GED/MS experiment was carried out at 1132(10) K. Besides the monomeric molecules, a small amount of the dimeric molecules (3.3(15) mol %) was detected. The non-planarity of the thermal-average structure of the monomer was completely ascribed to shrinkage effect, i.e. the equilibrium configuration was estimated to be planar. Anharmonic vibrational corrections to the experimental bond lengths rg(Ln–I) in lanthanide trihalides, ∆re = rg – re, were estimated to be between 0.002 and 0.018(1) Å using Morse constants. Shlykov SA, Giricheva NI, Lapykina EA, Girichev GV, Oberhammer H (2010) The molecular structure of Tbl3, Dyl3, Hol3 and Erl3 as determined by synchronous gas-phase electron diffraction and mass spectrometric experiment assisted by quantum chemical calculations. J Mol Struct 978 (1-3):170-177

137 CAS RN: 12401-65-9 MGD RN: 161979 GED augmented by MW and ab initio computations

Bond Na–I

re [Å] a 2.918(10)

Bond angle I–Na–I

θe [deg] a

Di-µ-iododisodium Sodium iodide dimer I2Na2 D2h

105.8(9)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit is the estimated standard deviation.

Both monomeric and dimeric molecules of sodium iodide were detected in the gas phase at Tnozzle = 848 K. The proportion of NaI units existing as dimer was determined to be 0.28(2). Anharmonic vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using PES from MP2/6-311+G(d) computation. The determined structure was found to be close to that from CCSD(T)/aug-cc-pwCVQZ computation. Wann DA, Rankin DWH, McCaffrey PD, Martin JML, Mawhorter RJ (2014) Equilibrium gas-phase structures of sodium fluoride, bromide, and iodide monomers and dimers. J Phys Chem A 118 (10):1927-1935

138 CAS RN: 13813-23-5 MGD RN: 506753 GED combined with MS and augmented by

Praseodymium(III) iodide Praseodymium triiodide I3Pr D3h (see comment)

120

2 Inorganic Molecules without Carbon Atoms

DFT computations

Bond Pr–I

rg [Å] a 2.916(6)

Bond angle I–Pr–I

θg [deg] a

PrI3

117.1(10)

Reproduced with permission of SNCSC. a

Parenthesized uncertainty in units of the last significant digit is estimated total error including 2.5σ and a systematic error of 0.002r.

The GED experiment was carried out at 1110(10) K. Besides the monomeric molecules, a small percentage of dimeric form (1.2(10) mol %) was detected in the saturated vapor of the title compound. Differences between the bond lengths of dimer and monomer were assumed at the values from B3LYP computation. Although the thermal-average structure is non-planar (C3v symmetry), the equilibrium structure was estimated to be planar (D3h point-group symmetry) accounting for the shrinkage effect. According to prediction of the computations, the molecule is planar with D3h symmetry. Giricheva NI, Shlykov SA, Lapykina EA, Oberhammer H, Girichev GV (2011) The molecular structure of PrI3 and GdI3 as determined by synchronous gas-phase electron diffraction and mass spectrometric experiment assisted by quantum chemical calculations. Struct Chem 22 (2):385-392

139 CAS RN: 13813-40-6 MGD RN: 213201 GED combined with MS and augmented by QC computations

Bond Tb–I

rg [Å] a 2.823(6)

Bond angle I–Tb–I

θg [deg] a

Terbium(III) iodide Terbium triiodide I3Tb D3h (see comment) TbI3

116.9(10)

Copyright 2010 with permission from Elsevier. a

Parenthesized uncertainty is estimated total error in units of the last significant digit.

The combined GED/MS experiment was carried out at 1117(10) K. Besides the monomeric molecules, a small amount of the dimeric molecules (0.9(13) mol %) was detected. The non-planarity of the thermal-average structure of the monomer was completely ascribed to shrinkage effect, i.e. the equilibrium configuration was estimated to be planar. Anharmonic vibrational corrections to the experimental bond lengths rg(Ln–I) in lanthanide trihalides, ∆re = rg – re, were simply estimated to be between 0.002 and 0.018(1) Å using Morse constants.

2 Inorganic Molecules without Carbon Atoms

121

Shlykov SA, Giricheva NI, Lapykina EA, Girichev GV, Oberhammer H (2010) The molecular structure of Tbl3, Dyl3, Hol3 and Erl3 as determined by synchronous gas-phase electron diffraction and mass spectrometric experiment assisted by quantum chemical calculations. J Mol Struct 978 (1-3):170-177

140 CAS RN: 209742-31-4 MGD RN: 141089 IR

Dinitrogen monoxide – krypton (1/1) Nitrous oxide – krypton (1/1) KrN2O Cs N

Distance Rcm b

r0 [Å] 3.5924

Angle

θ0 [deg] a

ϕ

c

N

O

Kr

a

83.02

Reprinted by permission of Taylor & Francis Ltd. Final version received 5 January 2011

a

Uncertainty was not given in the original paper. Distance between Kr and the center-of- mass of the N2O subunit. c Angle between Rcm and the N2O axis. b

The rotationally resolved IR spectrum of the title complex was recorded in a supersonic jet by a tunable diode laser spectrometer in the region of the ν1 symmetric stretching fundamental band of the N2O monomer at about 1285 cm-1. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 82Kr, 83Kr and 86Kr) assuming that the structural parameters of nitrous oxide were not changed upon complexation. Zheng R, Zhu Y, Li S, Duan C (2011) Infrared diode laser spectroscopy of the Kr-N2O van der Waals complex: the ν1 symmetric stretch region of N2O. Mol Phys 109(6):823-830

141 CAS RN: 77698-17-0 MGD RN: 385428 MW supported by DFT calculations

Distance S…Kr

Sulfur trioxide – krypton (1/1) KrO3S C3v O a

r0 [Å] 3.438(3)

Kr

S

O

O

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectra of the binary van der Waals complex of sulfur trioxide with krypton were recorded in a supersonic jet by a pulsed-jet FTMW spectrometer in the frequency region between 3.2 and 5.7 GHz.

122

2 Inorganic Molecules without Carbon Atoms

The partial r0 structure was obtained from the determined ground-state rotational constants of six isotopic species (main, 34S, 82Kr, 83Kr, 86Kr and 86Kr/34S) under the assumption that the structural parameters of the sulfur trioxide subunit were not changed upon complexation. Mackenzie RB, Timp BA, Mo Y, Leopold KR (2013) Effects of a remote binding partner on the electric field and electric field gradient at an atom in a weakly bound trimer. J Chem Phys 139(3):034320/1-034320/8 [http://dx.doi.org/10.1063/1.4811198]

142 CAS RN: 209742-32-5 MGD RN: 140900 IR supported by ab initio calculations

Distance Rcm b

r0 [Å] a 3.8090

Angle

θ0 [deg] a

c

ϕ

Dinitrogen monoxide - xenon (1/1) N2OXe Cs N

N

Xe

O

82.94

Copyright 2017 with permission from Elsevier.

a

Uncertainty was not given in original paper. Distance between Xe and the center-of-mass of the N2O subunit. c Angle between Rcm and the N=N=O axis. b

The rotationally resolved IR spectrum of the binary van der Waals complex of dinitrogen monoxide with xenon was recorded in a supersonic jet by a tunable diode laser spectrometer in the fundamental region ν1 of the N2O monomer at 1285 cm-1. The r0 structure was determined under the assumption that the structural parameters of the dinitrogen monoxide monomer subunit were not changed upon complexation. The complex was found to have a T-shaped configuration. Shi L, Zhao A, Wang H, Yang D, Zheng R (2017) Improving analysis of infrared spectrum of van der Waals complex with theoretical calculation: Applied to Xe-N2O complex. J Mol Spectrosc 333(3):12-18

143 CAS RN:15969-55-8 MGD RN: 535202 MW supported by ab initio calculations

Bonds N(1)=O(2) N(1)=O(3) N(1)–O(5) N(4)–O(5) N(4)=O(6)

Nitrosyl nitrate N 2O 4 C1 O

r0 [Å] a 1.2043(29) 1.2015(33) 1.4202(37) 1.6075(30) 1.1276(19)

rs [Å] a 1.2318(12) 1.1836(23) 1.3956(68) 1.6069(69) 1.1368(47)

N

N O

O

O

2 Inorganic Molecules without Carbon Atoms

123

Bond angles O(2)=N(1)–O(5) O(3)=N(1)–O(5) N(1)–O(5)–N(4) O(5)–N(4)=O(6)

θ0 [deg] a

θs [deg] a

Dihedral angles O(6)=N(4)–O(5)–N(1) N(4)–O(5)–N(1)=O(2)

τ0 [deg] a

τs [deg] a

117.76(33) 110.05(29) 110.05(34) 107.01(30)

176.4(16) -13.75(35)

117.12(20) 113.97(21) 111.17(28) 108.1(5)

177.4(10) -12.0(13)

Reproduced with permission of AIP Publishing. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of nitrosyl nitrate were recorded in a supersonic jet both by a chirped-pulse spectrometer and by a Balle-Flygare type FTMW spectrometer in the frequency region between 8 and 26.5 GHz. The compound was formed by a dimerization of nitrogen dioxide in the molecular beam. Only the anti conformer with the antiperiplanar O(6)=N(4)–O(5)–N(1) torsional angle was observed. The r0 and rs structures were determined from the ground-state rotational constants of twelve isotopic species (main, two 15N, 15N2, four 18O and four 18O2). Seifert NA, Zaleski DP, Fehnel R, Goswami M, Pate BH, Lehmann KK, Leung HO, Marshall MD, Stanton JF (2017) The gas-phase structure of the asymmetric, trans-dinitrogen tetroxide (N2O4), formed by dimerization of nitrogen dioxide (NO2), from rotational spectroscopy and ab initio quantum chemistry. J Chem Phys 146(13):134305/1-134305/7 [http://dx.doi.org/10.1063/1.4979182] 1λ4δ2-1,3,2,4-Dithiadiazete Disulfur dinitride N2S2 D2h

144 CAS RN: 25474-92-4 MGD RN: 401931 IR augmented by ab initio calculations Bond N–S

rz [Å]a 1.647694(95)

r see [Å]a 1.64182(33)

Bond angle N–S–N

θz [deg]a

θ see [deg]a

91.1125(33)

S

N

N

S

91.0716(93)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainty in units of the last significant digit.

The rotationally resolved mid-IR spectra of the ν6 (B-type) and the ν4 (C-type) fundamental bands of S2N2 were recorded by an FTIR spectrometer at 792 and 475 cm-1, respectively. The semiexperimental equilibrium structure was determined from the ground-state rotational constants by taking into account rovibrational corrections calculated with the CCSD(T)-F12a/cc-pVTZ-F12 harmonic and anharmonic (cubic) force fields. Perrin A, Flores Antognini A, Zeng X, Beckers H, Willner H, Rauhut G (2014) Vibrational spectrum and gasphase structure of disulfur dinitride (S2N2). Chem Eur J 20(33):10323-10331

124

2 Inorganic Molecules without Carbon Atoms

145 CAS RN: 191880-46-3 MGD RN: 215882 IR

Dinitrogen monoxide tetramer Nitrous oxide tetramer N 8O 4 D2d (I) S4 (II)

Distances d1 b d2 c r1d r2 f

I r0 [Å] a 4.051(3) 1.848(9) 4.039 e 3.481 e

II r0 [Å] a 3.448 2.948 3.880 e 3.515 e

Angle

θ0 [deg] a

θ0 [deg] a

g

ϕ1 ϕ2 h

5(3)

N

N

O

4

62.9 13.9

Reproduced with permission of AIP Publishing.

I Parenthesized uncertainties in units of the last significant digit are 1σ values for I; no uncertainties were given in the original paper for II. b Distance between centers of mass of diagonally opposite monomers. c Slip distance between the centers of mass of one diagonally opposite monomer pair and the other diagonally opposite pair. d Inner N–N distance for diagonally opposite monomers. e Dependent parameter. f Inner N–N distance for adjacent monomers. g Tilt angle between a monomer axis and the tetramer symmetry axis, with the positive value indicating that the O atoms are tilted outwards h Deviation from planarity for each monomer of the dimer pairs, with a positive value indicating O atoms inwards a

II

The rotationally resolved spectra of the nitrous oxide tetramer were recorded in a supersonic jet by a tunable diode laser spectrometer in the region of the N2O ν1 fundamental band at 2200 cm-1. Two distinct, but almost equally favorable, forms were observed, an oblate symmetric top structure with D2d symmetry (I) and a prolate symmetric top structure with S4 symmetry (II). The partial r0 structures were determined from the ground-state rotational constants of the main and 15N isotopic species under the assumption that the structural parameters of the monomer subunit were not changed upon complexation. Norooz Oliaee J, Dehghany M, Moazzen-Ahmadi N, McKellar ARW (2011) Nitrous oxide tetramer has two highly symmetric isomers. J Chem Phys 134(7):074310/1-074310/6 doi:10.1063/1.3555629

146 CAS RN: 73323-39-4 MGD RN: 216633 MW augmented by ab initio calculations

Bonds

r see [Å] a

Silicon oxide sulfide Silicon oxysulfide OSSi C∞ v O

Si

S

2 Inorganic Molecules without Carbon Atoms

O=Si Si=S

125

1.5064 1.9133

Reprinted with permission. Copyright 2011 American Chemical Society. a

Uncertainties were not given in the original paper.

The rotational spectrum of silicon oxide sulfide was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 42 GHz. The transient species was produced by an electrical discharge of a gas phase mixture of water, hydrogen sulfide, and silane. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants of eight isotopic species (main, 29Si, 30Si, 34S, 18O, 29Si/18O, 30Si/18O and 18O/34S) taking into account the rovibrational corrections calculated with the CCSD(T)/cc-pV(Q+d)Z quadratic and cubic force fields. Thorwirth S, Mück LA, Gauss J, Tamassia F, Lattanzi V, McCarthy MC (2011) Silicon oxysulfide, OSiS: Rotational spectrum, quantum-chemical calculations, and equilibrium structure. J Phys Chem Lett 2(11):12281231

147 CAS RN: 7446-09-5 MGD RN: 551982 IR

Bond S=O Bond angle O=S=O

re [Å] a 1.4307932(40)

Sulfur dioxide O2S C2v O

S

O

θe [deg] a

119.32898(24)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

Rotationally resolved vibrational spectra of 34S isotopically enriched sulfur dioxide were recorded by an FTIR spectrometer in the mid-IR region. The overtone bands 3ν2 and 2ν3 and the combination bands ν1+ν3, ν1+ν2+ν3 and 2ν1+ν3 were analyzed. The obtained rotational constants were fit together with the previously published rotational constants of lower-lying vibrational states in order to determine equilibrium rotational constants and rotation-vibration interaction constants. The equilibrium constants were fit together with the previously published ones for the parent isotopic species in order to determine the equilibrium structure. Lafferty WJ, Flaud JM, Ngom EHA, Sams RL (2009) 34S16O2: High-resolution analysis of the (030), (101), (111), (002) and (201) vibrational states; determination of equilibrium rotational constants for sulfur dioxide and anharmonic vibrational constants. J Mol Spectrosc 253(1):51-54

148 CAS RN: 126885-21-0 MGD RN: 426704 MW augmented by ab initio calculations

(Z)-1λ4,2λ4-Disulfene-1,2-dione cis-Disulfur dioxide O2S2 C2v

126

2 Inorganic Molecules without Carbon Atoms

Bonds S=O S=S

r see [Å] a 1.467(1) 2.011(3)

Bond angle S=S=O

θ see [deg] a

S

S

O

O

113.0(1)

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded by a millimeter- and submillimeter-wave absorption spectrometer in the frequency regions between 70 and 120 and between 340 and 500 GHz. The transient compound was produced by a radio-frequency discharge of sulfur dioxide. Only the cis isomer was detected. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants of two isotopic species (main and 34S) taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(Q+d)Z harmonic and anharmonic (cubic) force fields. Martin-Drumel MA, van Wijngaarden J, Zingsheim O, Lewen F, Harding ME, Schlemmer S, Thorwirth S (2015) Millimeter- and submillimeter-wave spectroscopy of disulfur dioxide, OSSO. J Mol Spectrosc 307:33-39

149 CAS RN: MGD RN: 429245 MW

Sulfur trioxide – xenon (1/1) O3SXe C3v O

Distance S…Xe

Xe

S

r0 [Å] a 3.577(2)

O

O

Copyright 2014 with permission from Elsevier. a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of the binary van der Waals complex of sulfur trioxide with xenon was recorded by a pulsed-nozzle FTMW spectrometer in the frequency region between 3 and 11 GHz. The r0 structure was determined from the ground-state rotational constants of nine isotopic species (main, seven different Xe and 34S) under the assumption that the planar structure of sulfur trioxide was not changed upon complexation. Dewberry CT, Huff AK, Mackenzie RB, Leopold KR (2014) Microwave spectrum, van der Waals bond length, and 131Xe quadrupole coupling constant of Xe-SO3. J Mol Spectrosc 304:43-46

150 CAS RN: 20816-12-0 MGD RN: 851468 IR, Ra

Osmium tetroxide O

O4Os Td

O

Os O

O

2 Inorganic Molecules without Carbon Atoms

Bond Os=O

127

re [Å] a 1.70919(16)

Reprinted with permission. Copyright 2012 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit.

Rotationally resolved vibrational spectra of isotopically pure osmium tetroxide were studied by high resolution FTIR (with a synchrotron light source) and high-resolution stimulated Raman spectroscopy. The ν1/ν3 stretching fundamental (940-980 cm-1) and the ν2/ν4 bending fundamental dyad (300-360 cm-1) were analyzed. The equilibrium structure re was determined from the experimental ground-state rotational and rovibrational interaction constants. Louviot M, Boudon V, Manceron L, Roy P, Bermejo D, Martinez RZ (2012) High-resolution spectroscopy and structure of osmium tetroxide. A benchmark study on 192OsO4. Inorg Chem 51(19):10356-10365 151 CAS RN: 72926-13-7 MGD RN: 529385 GED augmented by QC computations

Bond Sb–O

re [Å] a 1.9566(4)

Bond angles Sb–O–Sb O–Sb–O

θe [deg] a

2,4,6,8,9,10-Hexaoxa-1,3,5,7-tetrastibatricyclo[3.3.1.13,7]decane Tetraantimony hexoxide O6Sb4 Td

129.01(5) 98.15(3) b

Reproduced with permission from The Royal Society of Chemistry.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Dependent parameter.

The GED experiment was carried out at Teffusion cell = 750(7) K. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using quadratic and cubic force constants from HF computation (with cc-pVDZ and cc-pVDZ-PP basis sets for O and Sb, respectively) and taking into account non-linear kinematic effects. Masters SL, Girichev GV, Shylkov SA (2013) The re-determination of the molecular structure of antimony(III) oxide using very-high-temperature gas electron diffraction (VHT-GED). Dalton Trans 42 (10):3581-3586 152 CAS RN: 12185-10-3 MGD RN: 988018 GED

Bond P–P

rg [Å] a 2.1994(3)

Tetraphosphorous

P P

P4 Td P

P

128

2 Inorganic Molecules without Carbon Atoms

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit is 1σ value.

The GED experiment was carried out at Tnozzle=373 K. The molecule was assumed to have Td point-group symmetry. Cossairt BM, Cummins CC, Head AR, Lichtenberger DL, Berger RJF, Hayes SA, Mitzel NW, Wu G (2010) On the molecular and electronic structures of AsP3 and P4. J Am Chem Soc 132 (24):8459-8465

153 CAS RN: 179101-34-9 MGD RN: 209826 MW augmented by ab initio calculations

Thiadisilacycloprop-2-yne 2,3-Didehydrothiadisilirene SSi2 C2v Si

Bonds S–Si Si≡Si

r0 [Å] a 2.1335 2.3789

r see [Å] a 2.1301 2.3744

Bond angle Si–S–Si

θ0 [deg] a

θ see [deg] a

67.77

Si S

67.74

Reproduced with permission of AIP Publishing.

a

Uncertainties were not given in the original paper.

The rotational spectra of disilicon sulfide were detected in the region between 5 and 43 GHz by FTMW spectroscopy of a molecular beam. The transient species was produced by a low-current DC discharge of silane and hydrogen sulfide. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 29Si, 30 Si and 34S). The semiexperimental equilibrium structure r see was obtained taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(Q+d)Z harmonic and anharmonic (cubic) force fields. McCarthy MC, Gottlieb CA, Thaddeus P, Thorwirth S, Gauss J (2011) Rotational spectra and equilibrium structures of H2SiS and Si2S. J Chem Phys 134(3):034306/1-034306/10 doi:10.1063/1.3510732

154 CAS RN: 161297-21-8 MGD RN: 332275 MW augmented by ab initio calculations

Dithiasilacyclopro-3-ylidene S2Si C2v S Si:

Bonds S–S

r see [Å] a 2.1560(10)

S

2 Inorganic Molecules without Carbon Atoms

S–Si

2.1099(10)

Angle S–Si–S

θ see [deg] a

129

61.45(10)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The title compound was produced by a DC gas discharge of hydrogen sulfide and silane. Rotational spectra were recorded by an FTMW spectrometer. The semiexperimental equilibrium structure was determined from the ground-state rotational constants of three isotopic species (main, 29Si and 34S) accounting for the rovibrational corrections calculated with the CCSD(T)/cc-pCVTZ harmonic and anharmonic (cubic) force fields. Mück LA, Lattanzi V, Thorwirth S, McCarthy MC, Gauss J (2012) Cyclic SiS2: A new perspective on the Walsh rules. Angew Chem 124(15):3755-3758; Angew Chem Int Ed 51(15):3695-3698

130

2 Inorganic Molecules without Carbon Atoms

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14. 15.

16.

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Medcraft C, Mullaney JC, Walker NR, Legon AC (2017) A complex Ar⋅⋅⋅Ag-I produced by laser ablation and characterized by rotational spectroscopy and ab initio calculations: Variation of properties along the series Ar⋅⋅⋅Ag-X (X = F, Cl, Br and I). J Mol Spectrosc 335(5):61-67 Grubbs GS, Obenchain DA, Pickett HM, Novick SE (2014) H2-AgCl: A spectroscopic study of a dihydrogen complex. J Chem Phys 141(11): 114306/1-114306/10; erratum: J Chem Phys 143(2):029901/1-029901/2 (2015) Mikhailov VA, Roberts FJ, Stephens SL, Harris SJ, Tew DP, Harvey JN, Walker NR, Legon AC (2011) Monohydrates of cuprous chloride and argentous chloride: H2O⋅⋅⋅CuCl and H2O⋅⋅⋅AgCl characterized by rotational spectroscopy and ab initio calculations. J Chem Phys 134(13):134305/1-134305/12 Walker NR, Tew DP, Harris SJ, Wheatley DE, Legon AC (2011) Characterization of H2S⋅⋅⋅CuCl and H2S⋅⋅⋅AgCl isolated in the gas phase: A rigidly pyramidal geometry at sulfur revealed by rotational spectroscopy and ab initio calculations. J. Chem. Phys. 135(1):014307/1014307/10 Mikhailov VA, Tew DP, Walker NR, Legon AC (2010) H3N⋅⋅⋅Ag-Cl: Synthesis in a supersonic jet and characterization by rotational spectroscopy. Chem Phys Lett 499(1-3):16-20 Stephens SL, Tew DP, Walker NR, Legon AC (2011) Monohydrate of argentous fluoride: H2O⋅⋅⋅AgF characterized by rotational spectroscopy and ab initio calculations. J Mol Spectrosc 267(1-2):163-168 Okabayashi T, Yamamoto T, Mizuguchi D, Okabayashi EY, Tanimoto M (2012) Microwave spectroscopy of silver hydrosulfide AgSH. Chem Phys Lett 551:26-30 Dryza V, Bieske EJ (2011) Infrared spectroscopy of the Ag+-H2 complex: Exploring the connection between vibrational band-shifts and binding energies. J Phys Chem Lett 2(7):719724 Medcraft C, Gougoula E, Bittner DM, Mullaney JC, Blanco S, Tew DP, Walker NR, Legon AC (2017) Molecular geometries and other properties of H2O⋅⋅⋅AgI and H3N⋅⋅⋅AgI as characterized by rotational spectroscopy and ab initio calculations. J Chem Phys 147(23):234308/1-234308/8 (a) Riaz SZ, Stephens SL, Mizukami W, Tew DP, Walker NR, Legon AC (2012) H2S⋅⋅⋅Ag-I synthesized by a laser-ablation method and identified by its rotational spectrum. Chem Phys Lett 531:1-5 (b) Medcraft C, Bittner DM, Tew DP, Walker NR, Legon AC (2016) Geometries of H2S⋅⋅⋅MI (M = Cu, Ag, Au) complexes studied by rotational spectroscopy: The effect of the metal atom. J Chem Phys 145(19):194306/1-194306/10 See 9. Stephens SL, Tew DP, Walker NR, Legon AC (2016) H3P⋅⋅⋅AgI: generation by laser-ablation and characterization by rotational spectroscopy and ab initio calculations. Phys Chem Chem Phys 18(28):18971-18977 (a). Varga Z, Kolonits M, Hargittai M (2012) Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation. Struct Chem 23 (3):879-893 (b). Hargittai M, Kolonits M, Gödörházy L (1996) Molecular geometry of monomeric and dimeric aluminium tribromide from gas phase electron diffraction. Chem Phys Lett 257:321326 See 13(a). (a) See 13(a). (b) Hargittai M, Kolonits M, Tremmel J, Fourquet J-L, Ferey G (1990) The molecular geometry of iron trifluoride from electron diffraction and a reinvestigation of aluminum trifluoride. Struct Chem 1:75-78 (a) See 13(a). (b) Hargittai M, Réffy B, Kolonits M (2006) An intricate molecule: Aluminum triiodide. Molecular structure of AlI3 and Al2I6 from electron diffraction and computation. J Phys Chem A 110:3770-3777 (a) See 13(a). (b) See 13(b). See 13(a). (a) See 13(a). (b) See 16(b).

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Chapter 3. Molecules Containing One Carbon Atom 155 CAS RN: 361256-91-8 MGD RN: 333770 MW supported by ab initio calculations Distances C≡O Ag…C Ag–I

r0 [Å] a 1.1234(8) 2.051(1) 2.5336(4)

Silver iodide – carbon monoxide (1/1) CAgIO C∞v Ag

rs [Å] a 1.1236(5) 2.053(2) 2.530(2)

I

C

O

r (1) [Å] a m 1.12284(7) 2.05122(9) 2.5281(2)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the binary complex of silver iodide with carbon monoxide were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18 GHz. The transient complex was produced by a gas phase reaction of laser-ablated silver with tifluoroiodomethane and carbon monoxide. structures were determined from the ground-state rotational constants of three The r0, rs and mass-dependent r (1) m isotopic species (main, 109Ag and 13C). Stephens SL, Mizukami W, Tew DP, Walker NR, Legon AC (2012) Molecular geometry of OC⋅⋅⋅AgI determined by broadband rotational spectroscopy and ab initio calculations. J Chem Phys 136(6):064306/1064306/9 [http://dx.doi.org/10.1063/1.3683221] 156 CAS RN: 506-64-9 MGD RN: 531762 MW supported by DFT calculations Bonds Ag–C C≡N

r0 [Å] a 2.03324(45) 1.15527(67)

Silver(I) cyanide CAgN C∞v Ag

rs [Å] a 2.034182(27) 1.154733(20)

C

N

r (m2) [Å] a 2.031197(23) 1.160260(26)

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of silver cyanide was recorded in a free space cell by a source-modulated millimeterwave spectrometer in the frequency region between 97 and 400 GHz. The transient species was produced by a sputter reaction of silver with acetonitrile. Rotational transitions were assigned to the ground and first excited vibrational states. The r0, rs and r (m2) structures were determined from the ground-state rotational constants of six isotopic species (main, 13C, 15N, 109Ag, 109Ag/13C and 109Ag/15N). © Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_3

137

138

3 Molecules Containing One Carbon Atom

Okabayashi T, Okabayashi EY, Koto F, Ishida T, Tanimoto M (2009) Detection of free monomeric silver(I) and gold(I) cyanides, AgCN and AuCN: Microwave spectra and molecular structure. J Amer Chem Soc 131(33):11712-11718

157 CAS RN: 61192-70-9 MGD RN: 139310 MW augmented by ab initio calculations Bonds Al–N N≡C

Aluminum isocyanide CAlN C∞ v Al

N

C

r see [Å] a 1.8504(1) 1.1806(1)

Copyright 2014 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The r see structure was determined from the previously published experimental ground-state rotational constants of three isotopic species (main, 15N and 13C) taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)_ae/cc-pwCVTZ harmonic and anharmonic (cubic) force fields. Mück LA, Thorwirth S, Gauss J (2015) The semiexperimental equilibrium structures of AlCCH and AlNC. J Mol Spectrosc 311:49-53

158 CAS RN: MGD RN: 490996 MW supported by ab initio calculations

Chlorotrifluoromethane – argon (1/1) CArClF3 Cs F

F Ar

Distance Rcm b

r0 [Å] a 3.824(2)

Angle Cl…cm…Ar c

θ0 [deg] a

F

Cl

3.824(2)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit. Distance between Ar and the center-of-mass of the CClF3 subunit. c Center-of-mass of the CClF3 subunit is denoted by cm. b

The rotational spectrum of the binary van der Waals complex was studied by pulsed-jet FTMW spectroscopy in the spectral range between 6 and 18 GHz. The partial r0 structure was obtained from the ground-state rotational constants of two isotopic species (main and 37 Cl); the remaining structural parameters were fixed at the values from MP2/6-311++G(d,p) calculations.

3 Molecules Containing One Carbon Atom

139

The complex was found to have an almost L-shaped configuration with respect to the C-Cl bond. Evangelisti L, Gou Q, Feng G, Caminati W (2016) The rotational spectrum of CF3Cl-Ar. Chem Phys Lett 653(3):1-4

159 CAS RN: MGD RN: 103743 IR

Carbon disulfide – argon (1/1) CArS2 C2v S

Distance C…Ar

r0 [Å] a 3.708

Angle

θ0 [deg] a

ϕ

b

C

Ar

S

86.4

Copyright 2012 with permission from Elsevier.

a b

Uncertainty was not given in the original paper. The effective angle between the S=C=S axis and Ar…C.

The rotationally resolved mid-IR spectrum of the binary van der Waals complex was recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the region of the CS2 ν3 fundamental band at 1535 cm-1. The complex was found to have a T-shaped structure. The equilibrium structure is suggested to be of C2v symmetry. The r0 structure was determined under the assumption that the structural parameters of the carbon disulfide subunit were not changed upon complexation. Mivehvar F, Lauzin C, McKellar ARW, Moazzen-Ahmadi N (2012) Infrared spectra of rare gas-carbon disulfide complexes: He-CS2, Ne-CS2, and Ar-CS2. J Mol Spectrosc 281:24-27

160 CAS RN: 506-65-0 MGD RN: 157388 MW supported by DFT calculations

Bonds Au–C C≡N

r0 [Å] a 1.91251(16) 1.15856(24)

Gold(I) cyanide CAuN C∞ v Au

C

N

rs [Å] a 1.9122519(84) 1.1586545(97)

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of gold cyanide was recorded in a free space cell by a source-modulated millimeterwave spectrometer in the frequency region between 77 and 400 GHz. The transient species was produced by a sputter reaction of gold with acetonitrile. Rotational transitions were assigned to the ground and first excited vibrational states.

140

3 Molecules Containing One Carbon Atom

The r0 and rs structures were determined from the ground-state rotational constants of three isotopic species (main, 13C and 15N). Okabayashi T, Okabayashi EY, Koto F, Ishida T, Tanimoto M (2009) Detection of free monomeric silver(I) and gold(I) cyanides, AgCN and AuCN: Microwave spectra and molecular structure. J Amer Chem Soc 131(33):11712-11718

161

Carbonyltrifluoroborane Trifluoroborane – carbon monoxide (1/1)

CAS RN: 51006-66-7

MGD RN: 264760 MW augmented by QC calculations

Distances C≡O C–B O…B

r0 [Å] a 2.888(1)

CBF3O

C3v

F C

B

rs [Å] a

F

O

F

1.152(1) 2.886(1) 4.038(1)

θs [deg] a

Bond angle O≡C–B

180(1)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the binary complex of trifluoroborane with carbon monoxide was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The partial rs structure was determined from the ground-state rotational constants of four isotopic species (main, 10 B, 13C and 18O). The r0 distance between B and C was obtained assuming the remaining structural parameters at the values from MP2/6-311++G(d,p) calculations. The B, C and O atoms were found to be effectively collinear. Feng G, Gou Q, Evangelisti L, Grabow JU, Caminati W (2017) Pulsed jet Fourier transform microwave spectroscopy of the BF3-CO complex. J Mol Spectrosc 335(5):80-83

162 CAS RN: 165897-01-8 MGD RN: 133170 MW, IR augmented by ab initio calculations

Distance Rcm c

Carbon monoxide – bromine chloride (1/1)

re [Å] a,b 4.270(7)

Copyright 2013 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit. See comment for the significance of the structure. c Distance between the centers of mass of the subunits. b

CBrClO C∞ v O

C

Br

Cl

3 Molecules Containing One Carbon Atom

141

The rotationally resolved spectrum of the binary complex was recorded by a quantum cascade cw supersonic jet spectrometer in the mid-IR region. The results of analysis of the ν51, ν1, andν1+ν51 vibrational bands of the four most abundant isotopic species (main, 81Br, 37 Cl and 81Br/37Cl) together with previously published microwave data were used to fit a five-dimensional intermolecular PES. The presented structure corresponds to the global minimum of the semi-empirical PES. Rivera-Rivera LA, Scott KW, McElmurry BA, Lucchese RR, Bevan JW (2013) Compound model-morphed potentials contrasting OC-79Br35Cl with the halogen bonded OC-35Cl2 and hydrogen-bonded OC-HX (X=19F, 35 Cl, 79Br). Chem Phys 425:162-169

163 CAS RN: 90624-74-1 MGD RN: 117483 MW augmented by QC calculations

N-Bromodifluoromethylenimine Bromoimidocarbonyl fluoride CBrF2N Cs

Br

F

N

Bonds N–Br N=C C–F(2) C–F(1) Bond angles Br–N=C F–C–F F(2)–C=N F(1)–C=N

r0 [Å] a 1.867(5) 1.259(3) 1.307(3) 1.308(3)

F

θ0 [deg] a 113.5(5) 109.2(5) 120.4(5) 130.4(5)

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters were determined by adjusting the MP2_full/6-311++G(d) structure to the previously published experimental ground-state rotational constants of two isotopic species (main and 81Br). Durig JR, Zhou SX, Garner AX, Durig NE (2009) Structural parameters, centrifugal distortion constants, and vibrational spectra of F2C=NX (X = H, F, Cl, Br) molecules. J Mol Struct 922(1-3):11-18

164 CAS RN: 3644-72-2 MGD RN: 113029 MW augmented by QC calculations

Bonds Br–N N=C C=O

r0 [Å] a 1.857(5) 1.228(5) 1.161(5)

Bromine isocyanate CBrNO Cs Br N

C

O

142

Bond angles Br–N=C N=C=O

3 Molecules Containing One Carbon Atom

θ0 [deg] a 117.5(5) 172.3(5)

Copyright 2008 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters were obtained by adjusting the MP2/6-311+G(d,P) structure to the previously published ground-state rotational constants of three isotopic species (main, 81Br and 18O). The molecule was found to be planar with the bent N=C=O moiety. Durig JR, Zhou X, Durig NE, Nguyen D, Durig DT (2009) Vibrational spectra and structural parameters of some XNCO and XOCN (X = H, F, Cl, Br) molecules. J Mol Struct 917(1):37-51

165 CAS RN: 560-95-2 MGD RN: 677622 GED augmented by ab initio computations

Bonds Br–C C–N N=O(1) N=O(2)

re [Å] a 1.869(6) 1.529(3) 1.209(1) 1.214(1) b

Bond angles Br–C–N C–N=O(1) C–N=O(2) O(1)=N=O(2) N–C–N

θe [deg] a

Dihedral angles Br–C–N=O(1) Br–C–N=O(2)

τe [deg] a

ϕ1 e ϕ2f

Bromotrinitromethane CBrN3O6 C3

rg [Å] a 1.878(6) 1.548(3) 1.215(1) 1.218(1)

112.5(3) 115.7(2) 115.9(2) c 128.3(4) d 106.3(3) d

-38.3(13) 139.6(24) d 1.9(18) d -1.9(18) d

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission [a].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Difference to N=O(1) was assumed at the value from MP2/SDB-cc-pVTZ computations. c Difference to C–N=O(1) was assumed at the value from calculations at the level of theory as indicated above. d Dependent parameter. e Angle between the O(1)=N bond and the CNO(2) plane. f Angle between the O(2)=N bond and the CNO(1) plane. b

3 Molecules Containing One Carbon Atom

143

Molecular structure from Ref. [b] was reinvestigated. The experiment was carried out at Tnozzle = 353 K. The molecule was assumed to have the C3 point-group symmetry. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using quadratic and cubic force constants from computation at the level of theory as indicated above and taking into account non-linear kinematic effects. A propeller-type twisting of the nitro groups was explained by the competing N…O and Br…O interactions. a. Klapötke TM, Krumm B, Moll R, Rest SF, Vishnevskiy YV, Reuter C, Stammler HG, Mitzel NW (2014) Halogenotrinitromethanes: A combined study in the crystalline and gaseous phase and using quantum chemical methods. Chem Eur J 20 (40):12962-12973 b. Sadova NI, Popik NI, Vilkov LV (1976) Electron-diffraction investigation of the structure of the HC(NO2)3, ClC(NO2)3, and BrC(NO2)3 molecules in the gas phase. J Struct Chem/Zh Strukt Khim. 17/17 (2/2):257262/298-303

166 CAS RN: 28245-33-2 MGD RN: 774041 MW augmented by QC calculations

N-Chlorodifluoromethylenimine Chloroimidocarbonyl fluoride CClF2N Cs F

Cl

N

Bonds N–Cl N=C C–F(2) C–F(1) Bond angles Cl–N=C F–C–F F(2)–C=N F(1)–C=N

a

r0 [Å] 1.713(5) 1.260(3) 1.304(3) 1.307(3)

F

θ0 [deg] a 113.2(5) 110.0(5) 120.3(5) 129.7(5)

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure was determined by adjusting the MP2_full/6-311++G(d) structure to the previously published experimental ground-state rotational constants of two isotopic species (main, 37Cl). Durig JR, Zhou SX, Garner AX, Durig NE (2009) Structural parameters, centrifugal distortion constants, and vibrational spectra of F2C=NX (X = H, F, Cl, Br) molecules. J Mol Struct 922(1-3):11-18

167 CAS RN: 13858-09-8 MGD RN: 803460 MW augmented by ab initio calculations

Bonds

r0 [Å]

Chlorine isocyanate CClNO Cs Cl

a

N

C

O

144

3 Molecules Containing One Carbon Atom

Cl–N N=C C=O

1.706(5) 1.225(5) 1.162(5)

Bond angles Cl–N=C N=C=O

θ0 [deg] a 118.9(5) 171.0(5)

Copyright 2008 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters were determined by adjusting the MP2/6-311+G(d,p) structure to the previously published ground-state rotational constants of three isotopic species (main, 37Cl and 18O). The molecule was found to be planar with the bent N=C=O moiety. Durig JR, Zhou X, Durig NE, Nguyen D, Durig DT (2009) Vibrational spectra and structural parameters of some XNCO and XOCN (X = H, F, Cl, Br) molecules. J Mol Struct 917(1):37-51

168 CAS RN: 75-71-8 MGD RN: 890168 MW augmented by QC calculations

Bonds C–F C–Cl

r see [Å] a 1.3287(8) 1.7519(7)

Bond angles F–C–F Cl–C–Cl F–C–Cl

θ see [deg] a

Dichlorodifluoromethane CCl2F2 C2v Cl

F

Cl

F

107.75(9) 111.62(7) 109.35(1)

Reprinted by permission of Taylor & Francis Ltd. Final version received 10 April 2014

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure was determined from the previously published ground-state rotational constants taking into account rovibrational corrections calculated with the B3LYP/6-311+G(3df,2pd) harmonic and anharmonic (cubic) force fields. These results were used for benchmarking the CCSD(T)_ae/ccpwCVQZ calculations. Vogt N, Demaison J, Rudolph HD (2014) Accurate equilibrium structures of fluoro- and chloroderivatives of methane. Mol Phys 112(22):2873-2883

169 CAS RN: 1858-29-3

Phosphorisocyanatidous dichloride Dichloroisocyanatophosphine

3 Molecules Containing One Carbon Atom

145

MGD RN: 482150 GED augmented by QC computations

CCl2NOP C1 (gauche) Cl

a

Bonds P–Cl P–N N=C C=O

re [Å] 2.036(1) 1.657(3) 1.198(1) b 1.155(1) b

Bond angles Cl–P–Cl Cl–P–N P–N=C N–C=O

θe [deg] a

Dihedral angle Cl–P–N=C

τe [deg] a

O

a

rg [Å] 2.045(1) 1.667(3) 1.203(1) 1.159(1)

P

C N

Cl

99.4(2) 100.1(2) 137.2(6) c 171.5(6) c

129.2(2)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Difference between the N=C and C=O bond lengths was assumed at the value from MP2/aug-cc-pVTZ calculation. c Difference between the P–N=C and N–C=O bond angles was assumed at the value from computation as indicated above. b

Three different conformers, syn, anti and gauche, characterized by different C=N–P…X torsion angles (X is the bisector of the Cl–P–Cl angle), were predicted by various DFT and ab initio computations. The GED experiment was carried out at Tnozzle =292 K. The preference of the gauche conformer was unambiguously ascertained in the GED analysis. Because of the low barrier to rotation of the isocyanato group around the P–N bond (up to 0.7 kcal mol-1), dynamic model was applied in the GED analysis employing the PES profile from MP2/aug-cc-pVTZ computation. Structural differences between the pseudo-conformers were adopted from the computations. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using quadratic and cubic force constants from computation at the level of theory as indicated above and taking into account non-linear kinematic effects. Only one conformer was indicated by gas phase IR vibrational spectroscopy. Li DQ, Schwabedissen J, Stammler HG, Mitzel NW, Willner H, Zeng XQ (2016) Dichlorophosphanyl isocyanate - spectroscopy, conformation and molecular structure in the gas phase and the solid state. Phys Chem Chem Phys 18 (37):26245-26253

170 CAS RN: 75-44-5 MGD RN: 584337 MW augmented by ab initio calculations

Carbonic dichloride Carbonyl dichloride Phosgene CCl2O C2v O

Bonds C=O C–Cl

r see [Å] a 1.1759(4) 1.7375(2)

Cl

Cl

146

Bond angle Cl–C–Cl

3 Molecules Containing One Carbon Atom

θ see [deg] a 111.85(2)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

A semiexperimental equilibrium structure r see of the title molecule was determined from the previously published experimental ground-state rotational constants of nine isotopic species taking into account rovibrational corrections calculated with the MP2/cc-pV(T+d)Z harmonic and anharmonic (cubic) force fields. Demaison J, Császár AG (2012) Equilibrium CO bond lengths. J Mol Struct 1023:7-14

171 CAS RN: 56-23-5 MGD RN: 956069 GED combined with MS and augmented by QC computations

Distances C–Cl Cl...Cl

ra [Å] a 1.768(2) 2.885(1)

rg [Å] a 1.770(2) 2.887(1)

Tetrachloromethane

Cl

rα [Å] a 1.767(2) 2.886(1)

rh1 [Å] a 1.769(2) 2.888(1)

Cl

CCl4 Td Cl

Cl

Copyright 2010 with permission from Elsevier [a].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

Determination of structural parameters was carried out in order to test an improved scanning and initial data processing technique applied for photographic registration. The temperature of the GED experiment was not stated, probably room temperature. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1 and ∆rα = ra − rα, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. The equilibrium bond length re(C–Cl) of 1.769 Å, computed at the CCSD(T)_ae/aug-cc-pVTZ level, was found to be close to the rh1(C–Cl) value. a. Zakharov AV, Zhabanov YA (2010) An improved data reduction procedure for processing electron diffraction images and its application to structural study of carbon tetrachloride. J Mol Struct 978 (1-3):61-66 GED

Distances C–Cl Cl...Cl

rg [Å] a 1.7671(13) 2.8883(7)

Reproduced with permission of SNCSC [b].

a

Parenthesized uncertainties in units of the last significant digit are 2.5σ values.

3 Molecules Containing One Carbon Atom

147

The GED experiment was carried out at room temperature in order to test a commercial imaging plate reader FLA7000 (Fuji) used for non-photographic registration. The determined internuclear distances and root-mean square vibrational amplitudes were found to be in excellent agreement with those obtained in the GED experiment with photographic registration [c]. b. Vogt N, Rudert R, Rykov AN, Karasev NM, Shishkov IF, Vogt J (2011) Use of imaging plates (IPs) in the gas-phase electron diffraction (GED) experiments on the EG-100 M apparatus. The tetrachloromethane molecule as a test object. Struct Chem 22 (2):287-291 c. Morino Y, Nakamura Y, Iijima T (1960) Mean square amplitudes and force constants of tetrahedral molecules. I. Carbon tetrachloride and germanium tetrachloride. J Chem Phys 32(3):643-652

172 CAS RN: 4775-58-0 MGD RN: 361142 GED augmented by QC computations

1,1',1'',1'''-Methanetetrayltetrakis(1,1,1-trichlorosilane) 1,1,1,3,3,3-Hexachloro-2,2-bis(trichlorosilyl)-1,3-disilapropane CCl12Si4 Td (see comment) SiCl3

Bonds C(2)–Si(2) Si(2)–Cl(4)

rg [Å] a 1.986(5) 2.036(9)

Bond angles Si–C–Si C(2)–Si(2)–Cl(4)

θa [deg] a

Dihedral angle Si(3)–C(2)–Si(2)–Cl(4)

τa [deg] a

Cl3Si Cl3Si

SiCl3

109.3(25) 112.3(5)

12(9) b

Reproduced with permission of SNCSC.

a b

Parenthesized uncertainties in units of the last significant digit are 3σ values. Deviation from 180°.

The GED experiment was carried out at Tnozzle = 303(5) K. The observed non-planarity of the Si(3)–C(2)–Si(2)–Cl(4) unit can be ascribed to shrinkage effect. According to predictions of HF and B3LYP computations (with the 6-311G(d) basis set), the title molecule possesses Td overall symmetry and each of the silyl groups has local C3v symmetry. The barrier to internal rotation of the SiCl3 group around the Si−C bond was estimated to be 148.7 kJ mol−1 (HF/6-311G(d)). Ezhov YS, Komarov SA, Simonenko EP, Pavelko RG, Sevast'yanov VG, Kuznetsov NT (2009) Molecular structure of C(SiCl3)4 tetrakis(trichlorosilyl)methane. J Struct Chem (Engl Transl)/Zh Strukt Khim 50/50 (1/1):153-157/160-164

173 CAS RN: 1840-42-2 MGD RN: 518715 GED augmented by ab initio computations

Bonds

re [Å] a

Fluorotrinitromethane CFN3O6 C3

rg [Å] a

148

3 Molecules Containing One Carbon Atom

F–C C–N N=O(1) N=O(2)

1.300(11) 1.517(4) 1.210(1) 1.211(1) b

Bond angles F–C–N C–N=O(1) C–N=O(2) O(1)=N=O(2) N–C–N

θe [deg] a

110.2(6) 114.1(3) 116.3(3) c 129.5(6) d 108.7(6) d

Dihedral angles F–C–N=O(1) F–C–N=O(2)

ϕ1 e ϕ2f

1.308(11) 1.532(4) 1.216(1) 1.216(1)

τe [deg] a

-37.9(22) 143.9(31) d -1.6(20) d 1.5(20) d

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ. Difference to N=O(1) was assumed at the value from MP2/cc-pVTZ computation. c Difference to C–N=O(1) was assumed at the value from calculation at the level of theory as indicated above. d Dependent parameter. e Angle between the O(1)=N bond and the CNO(2) plane. f Angle between the O(2)=N bond and the CNO(1) plane. b

The GED experiment was carried out at Tnozzle = 295 K. The molecule was assumed to have the C3 point-group symmetry. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using quadratic and cubic force constants from MP2/cc-pVTZ computation and taking into account non-linear kinematic effects. A propeller-type twisting of the nitro groups was explained by the competing N…O and F…O interactions. Klapötke TM, Krumm B, Moll R, Rest SF, Vishnevskiy YV, Reuter C, Stammler HG, Mitzel NW (2014) Halogenotrinitromethanes: A combined study in the crystalline and gaseous phase and using quantum chemical methods. Chem Eur J 20 (40):12962-12973

174 CAS RN: 89831-20-9 MGD RN: 146940 MW supported by ab initio calculations

Bonds C–F C=O C=O Bond angle

r0 [Å] a 1.3204(87) 1.2407(38) b 1.2402(38) c

Fluorooxomethoxy Fluoroformyloxy CFO2 C2v O

rs [Å] a 1.3122(61) 1.2386(26)

θs [deg] a

120.14(23)

F

O

3 Molecules Containing One Carbon Atom

149

Reprinted with permission. Copyright 2013 American Chemical Society. a

Parenthesized errors in units of the last digit are one standard deviation. O species. c 18 O isotopic species. b 16

In addition to previous MW studies the rotational spectrum of the singly 18O substituted isotopic species of the fluorooxomethoxy radical was recorded by a millimeter-wave spectrometer in the frequency regions 160-177 and 250-269 GHz. The r0 and rs structures were determined from the ground-state rotational constants of three isotopic species (main, 18O and 18O2). Koucký J, Kania P, Uhlíková T, Kolesniková L, Beckers H, Willner H, Urban S (2013) Geometry and microwave rotational spectrum of the FC16O18O. radical. J Phys Chem A 117(39):10138-10143

175 CAS RN: 353-50-4 MGD RN: 862182 MW augmented by ab initio calculations Bonds C=O C–F Bond angle F–C–F

Carbonic difluoride Carbonyl difluoride CF2O C2v O

F

F

r see [Å] a 1.1699(4) 1.3100(2)

θ see [deg] a 107.80(3)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see of the title molecule was determined from the previously published experimental ground-state rotational constants of four isotopic species taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Demaison J, Császár AG (2012) Equilibrium CO bond lengths. J Mol Struct 1023:7-14

176 CAS RN: 1354553-04-0 MGD RN: 309002 MW

Trifluoroiodomethane – krypton (1/1) CF3IKr C3v F

Distances Rcm b I…Kr

r0 [Å] a 4.7201(2) 3.8299(7)

F Kr

F

I

150

Angle

ϕ

c

3 Molecules Containing One Carbon Atom

θ0 [deg] a 5.0(5)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Distance between Kr and the center-of-mass of the CF3I subunit. c Angle between the C3 axis of the CF3I subunit and Rcm. b

The rotational spectra of the binary van der Waals complex of trifluoroiodomethane with krypton were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 7 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 86Kr) under the assumption that the structural parameters of the trifluoroiodomethane subunit were not changed upon complexation. Stephens SL, Walker NR, Legon AC (2011) Rotational spectra and properties of complexes B⋅⋅⋅ICF3 (B = Kr or CO) and a comparison of the efficacy of ICl and ICF3 as iodine donors in halogen bond formation. J Chem Phys 135(22):224309/1-224309/8 doi:10.1063/1.3664314

177 CAS RN: MGD RN: 411611 MW

Trifluoroiodomethane – dinitrogen (1/1) CF3IN2 C3v F

Distance N…I

r0 [Å] a 3.443(1)

Angle

θ0 [Å] a

α

b

I

F

N

N

F

19.8(5)

Copyright 2015 with permission from Elsevier.

a b

Parenthesized uncertainty in units of the last significant digit. Angular oscillation of the N2 subunit about the C3 axis of the complex.

The rotational spectrum of the binary complex was recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the spectral range between 6 and 18.5 GHz. The partial r0 structure was obtained from the ground-state rotational constants of two isotopic species (main and 15 N2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Anable JP, Hird DE, Stephens SL, Zaleski DP, Walker NR, Legon AC (2015) Characterization of the weak halogen bond in N2⋅⋅⋅ICF3 by pure rotational spectroscopy. Chem Phys Lett 625:179-185

178 CAS RN: 338-66-9 MGD RN: 684361

Fluorocarbonimidic difluoride Fluoroimidocarbonyl fluoride CF3N

3 Molecules Containing One Carbon Atom

151

MW augmented by QC calculations

Bonds N–F N=C C–F(2) C–F(1)

Cs F

r0 [Å] a 1.390(3) 1.272(3) 1.300(3) 1.297(3)

Bond angles F–N–C F–C–F F(2)–C=N F(1)–C=N

F N

F

θ0 [deg] a 107.8(5) 112.2(5) 119.5(5) 128.3(5)

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure was determined by adjusting the MP2_full/6-311++G(d) structure to the previously published experimental ground-state rotational constants of the parent isotopic species. Durig JR, Zhou SX, Garner AX, Durig NE (2009) Structural parameters, centrifugal distortion constants, and vibrational spectra of F2C=NX (X = H, F, Cl, Br) molecules. J Mol Struct 922(1-3):11-18

179

Pentafluoro(trifluoromethyl)sulfur

Trifluoromethylsulfur pentafluoride

CAS RN. 373-80-8

MGD RN: 806669 MW

CF8S

C4v (see comment) F

F

F

Bond C–S

a

rs [Å] 1.8808(7)

Copyright 2017 with permission from Elsevier. a

F

F S

F

F F

Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of pentafluoro(trifluoromethyl)sulfur was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 4 and 22 GHz. The main isotopic species as well as the 13C and 34S isotopic species were studied in natural abundance. The twelve-fold barrier to internal rotation in the molecule was determined to be close to zero, i.e. the symmetry of the overall-rotation wavefunction was found to be identical with C4v symmetry. Hirota E, Kawasima Y, Ajiki K (2017) Internal rotation in trifluoromethylsulfur pentafluoride: CF3SF5 by Fourier transform microwave spectroscopy. J Mol Spectrosc 342(6):100-108

180 CAS RN: 73963-95-8 MGD RN: 142246

Iron cyanide CFeN

152

3 Molecules Containing One Carbon Atom

MW

C∞ v Fe

Bonds Fe–C C≡N

r0 [Å] a 1.9244(8) 1.157(1)

rs [Å] a 1.9355(68) 1.146(23)

C

N

[Å] a r (1) m 1.917(12) 1.128(21)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of iron cyanide (4∆i electronic ground state) was investigated by millimeter/submillimeter-wave direct absorption spectroscopy in the frequency region between 140 and 500 GHz. The radicals were produced by an AC discharge of ironpentacarbonyl and cyanogen. The r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 13 C). The substitution rs and a mass-dependent r (1) structures were obtained for the spin level Ω=7/2. m Flory MA, Ziurys LM (2011) Millimeter-wave rotational spectroscopy of FeCN (X4Δi) and FeNC (X6Δi): Determining the lowest energy isomer. J Chem Phys 135(18):184303/1-184303/11 doi:10.1063/1.3653809

181 CAS RN: 71701-40-1 MGD RN: 134603 MW augmented by ab initio calculations

Bonds Fe–C C≡O

Iron monocarbonyl CFeO C∞ v Fe

C

O

re [Å] a 1.725 1.1587 b

Reproduced with permission of AIP Publishing.

a b

Uncertainties were not given in the original paper. Assumed according to ab initio calculations.

The rotational spectra of iron monocarbonyl (3Σ- electronic ground state) were recorded for the first excited vibrational states of ν2 bending andν3 stretching by millimeter-wave absorption spectroscopy in the frequency region between 286 and 325 GHz. The radicals were produced by UV photolysis of ironpentacarbonyl. From the excited vibrational state rotational constants and the previously published ground-state constants a partial equilibrium structure re was determined. Tanaka K, Nakamura M, Shirasaka M, Sakamoto A, Harada K, Tanaka T (2015) Millimeter-wave spectroscopy of the FeCO radical in the ν2 and ν3 vibrationally excited states. J Chem Phys 143(1):014303/1-014303/10 [http://dx.doi.org/10.1063/1.4923215]

182 CAS RN: 75-25-2

Tribromomethane Bromoform

3 Molecules Containing One Carbon Atom

153

CHBr3 C3v

MGD RN: 728903 MW

Br

Bonds C–H C–Br

rz [Å] a 1.0831(32) 1.9260(3)

Bond angles H–C–Br Br–C–Br

θz [deg] a

Br

Br

107.622(27) 111.255(25)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the spectral range between 2 and 8 GHz as well at room temperature by a millimeter-wave spectrometer in the range up to 318 GHz. The rz structure was determined from 18 ground-state rotational constants of eight isotopic species (main, singly, doubly and triply substituted 81Br species, as well as their D species). Kisiel Z, Kraśnicki A, Pszczółkowski L, Shipman ST, Alvarez-Valtierra L, Pate BH (2009) Assignment and analysis of the rotational spectrum of bromoform enabled by broadband FTMW spectroscopy. J Mol Spectrosc 257(2):177-186

183 CAS RN: 75-45-6 MGD RN: 583666 MW augmented by ab initio calculations Bonds C–H C–F C–Cl Bond angles H–C–F H–C–Cl F–C–Cl F–C–F

r see [Å] a 1.0850(11) 1.3363(5) 1.7560(9)

Chlorodifluoromethane CHClF2 Cs H

F

Cl

F

θ see [deg] a 109.97(4) 109.60(6) 109.62(4) 108.06(6)

Reprinted by permission of Taylor & Francis Ltd. Final version received 10 April 2014

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure was determined from the previously published ground-state rotational constants taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-

154

3 Molecules Containing One Carbon Atom

pV(T+d)Z harmonic and anharmonic (cubic) force fields. These results were used for benchmarking the CCSD(T)_ae/cc-pwCVQZ calculations. Vogt N, Demaison J, Rudolph HD (2014) Accurate equilibrium structures of fluoro- and chloroderivatives of methane. Mol Phys 112(22):2873-2883

184 CAS RN: 2712-98-3 MGD RN: 119704 MW augmented by QC calculations

Carbonimidic difluoride Imidocarbonyl fluoride CHF2N Cs F

H

N a

Bonds N–H N=C C–F(2) C–F(1)

r0 [Å] 1.017(2) 1.238(3) 1.300(3) 1.300(3)

F

θ0 [deg] a

Bond angles H–N=C F–C–F F(2)–C=N F(1)–C=N

112.1(3) 108.1(3) 123.4(3) 128.5(3)

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure was determined by adjusting the MP2_full/6-311++G(d) structure to the previously published experimental ground-state rotational constants of four isotopic species. Durig JR, Zhou SX, Garner AX, Durig NE (2009) Structural parameters, centrifugal distortion constants, and vibrational spectra of F2C=NX (X = H, F, Cl, Br) molecules. J Mol Struct 922(1-3):11-18

185 CAS RN: 74-90-8 MGD RN: 806196 MW

Hydrogen cyanide CHN C∞ v H

Bonds H–C C≡N

r0 [Å] a 1.065049(6) 1.153317(2)

[Å] a r (1) m 1.065042(5) 1.153225(23)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

C

N

3 Molecules Containing One Carbon Atom

155

The r0 and r (1) structures were determined from the previously published ground-state rotational constants of m four isotopic species (main, 13C, 15N and 13C/15N). Vogt N, Vogt J, Demaison J (2011) Accuracy of the rotational constants. J Mol Struct 988(1-3):119-127

186 CAS RN: 75-13-8 MGD RN: 550070 MW augmented by QC calculations

Bonds H–N N=C C=O Bond angles H–N=C N–C=O

Hydrogen isocyanate CHNO Cs H N

r0 [Å] a 0.995(3) 1.216(3) 1.165(3)

C

O

θ0 [deg] a 126.1(5) 172.6(5)

Copyright 2008 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters were obtained by adjusting the MP2/6-311+G(d,p) structure to the previously published ground-state rotational constants of five isotopic species (main, D, 15N, 13C and 18O). The molecule was found to be planar with the bent N=C=O moiety. Durig JR, Zhou X, Durig NE, Nguyen D, Durig DT (2009) Vibrational spectra and structural parameters of some XNCO and XOCN (X = H, F, Cl, Br) molecules. J Mol Struct 917(1):37-51

187 CAS RN: 3129-90-6 MGD RN: 901163 MW augmented by ab initio calculations

Hydrogen isothiocyanate Isothiocyanic acid CHNS Cs N H

Bonds H–N N=C C=S Bond angles H–N=C N=C=S

r0 [Å] a 0.961(7) 1.215(10) 1.563(8)

r e [Å] a 0.993(13) 1.205(17) 1.568(13)

θ0 [deg] a

θ see [deg] a

130.5(53) 173(15)

se

131.0(8) 172.7(26)

Reproduced with permission from the PCCP Owner Societies.

C S

156 a

3 Molecules Containing One Carbon Atom

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of hydrogen isothiocyanate were recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the frequency region between 5 and 43 GHz. The r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 15N, se 13 C, 34 S and D). The semiexperimental equilibrium structure r e was obtained from the experimental rotational constants taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(Q+d)Z harmonic and anharmonic (cubic) force fields. McGuire BA, Martin-Drumel MA, Thorwirth S, Brünken S, Lattanzi V, Neill JL, Spezzano S, Yu Z, Zaleski DP, Remijan AJ, Pate BH, McCarthy MC (2016) Molecular polymorphism: microwave spectra, equilibrium structures, and an astronomical investigation of the HNCS isomeric family. Phys Chem Chem Phys 18(32):22693-22705

188 CAS RN: 463-56-9 MGD RN: 159394 MW augmented by ab initio calculations

Thiocyanic acid CHNS Cs S H

Bonds H–S S–C C≡N Bond angles H–S–C S–C≡N

a

r0 [Å] 1.342(9) 1.708(13) 1.152(19)

θ0 [deg] a

92.8(7) 171.0(25)

a

r [Å] 1.340(1) 1.699(3) 1.153(4) se e

C N

θ see [deg] a 94.3(4) 175.8(12)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of thiocyanic acid were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5 and 43 GHz. The r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 34S, se 13 C, 15N, D, 34S/D and 15N/D). The semiexperimental equilibrium structure r e was obtained from the experimental rotational constants taking into account rovibrational corrections calculated with the CCSD(T)/ccpV(Q+d)Z harmonic and anharmonic (cubic) force fields. McGuire BA, Martin-Drumel MA, Thorwirth S, Brünken S, Lattanzi V, Neill JL, Spezzano S, Yu Z, Zaleski DP, Remijan AJ, Pate BH, McCarthy MC (2016) Molecular polymorphism: microwave spectra, equilibrium structures, and an astronomical investigation of the HNCS isomeric family. Phys Chem Chem Phys 18(32):22693-22705

189 CAS RN: 65195-59-7

Thiofulminic acid

3 Molecules Containing One Carbon Atom

157

CHNS C∞ v

MGD RN: 212310 MW augmented by ab initio calculations Bonds H–C C≡N N=S

H

C

N

S

r see [Å] a 1.059(1) 1.160(2) 1.600(2)

r0 [Å] a 1.051(1) 1.169(3) 1.593(3)

Reproduced with permission from the PCCP Owner Societies. a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of thiofulminic acid were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5 and 43 GHz. The r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 13C, 15 N, 34S and D). The semiexperimental equilibrium structure r see was obtained from the experimental ground-state rotational constants taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(Q+d)Z harmonic and anharmonic (cubic) force constants. McGuire BA, Martin-Drumel MA, Thorwirth S, Brünken S, Lattanzi V, Neill JL, Spezzano S, Yu Z, Zaleski DP, Remijan AJ, Pate BH, McCarthy MC (2016) Molecular polymorphism: microwave spectra, equilibrium structures, and an astronomical investigation of the HNCS isomeric family. Phys Chem Chem Phys 18(32):22693-22705

190 CAS RN: 944411-24-9 MGD RN: 212112 MW augmented by ab initio calculations

Isothiofulminic acid

S H

CHNS Cs N C

Bonds H–S S–N N≡C Bond angles H–S–N S–N–C

a

r0 [Å] 1.327(2) 1.660(1) 1.175(2)

θ0 [deg] a 95.37 b 173.7 b

a

r [Å] 1.324(3) 1.661(2) 1.171(3) se e

θ see [deg] a 95.37 b 173.7 b

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Constrained to theoretical value.

The rotational spectra of isothiofulminic acid were recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the frequency region between 5 and 43 GHz. The r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 34S, se 15 N, 13C and D). The semiexperimental equilibrium structure r e was obtained from the experimental ground-state

158

3 Molecules Containing One Carbon Atom

rotational constants taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(Q+d)Z harmonic and anharmonic (cubic) force constants. McGuire BA, Martin-Drumel MA, Thorwirth S, Brünken S, Lattanzi V, Neill JL, Spezzano S, Yu Z, Zaleski DP, Remijan AJ, Pate BH, McCarthy MC (2016) Molecular polymorphism: microwave spectra, equilibrium structures, and an astronomical investigation of the HNCS isomeric family. Phys Chem Chem Phys 18(32):22693-22705

191 CAS RN: 1218779-93-1 MGD RN: 208497 MW

(Cyano-C)hydrozinc CHNZn C∞ v H

Bonds H–Zn Zn–C C≡N

r0 [Å] a 1.4965 (13) 1.9014 (37) 1.1504 (54)

rs [Å] b 1.4972 1.8994 1.1476

Zn

C

N

r (1) [Å] a m 1.4950 (3) 1.8966 (6) 1.1459 (6)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit are 3σ values. Uncertainties were not given in the original paper.

The rotational spectra of the title compound (1Σ+ electronic ground state) were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 7 and 39 GHz. The transient species were produced by a DC discharge of dimethylzinc and cyanogen. structures were determined from the ground-state rotational constants of seven The r0, rs and mass-dependent r (1) m isotopic species (main, 66Zn, 67Zn, 68Zn, 13C, D and 66Zn/D). Sun M, Apponi AJ, Ziurys LM (2009) Fourier transform microwave spectroscopy of HZnCN (X1Σ+) and ZnCN (X2Σ+). J Chem Phys 130(3):034309/1-034309/10 doi: 10.1063/1.3049444

192 CAS RN: 2564-86-5 MGD RN: 965214 MW augmented by ab initio calculations

Hydroxyoxomethyl CHO2 Cs C O

Bonds H–O(1) O(1)–C C=O(2) Bond angles H–O(1)–C O(1)–C=O(2)

syn r0 [Å] a 0.980(16) 1.330(12) 1.186(12)

r see [Å] a 0.972(1) 1.326(1) 1.182(1)

anti r0 [Å] a 0.962(19) 1.346(11) 1.180(11)

r see [Å] a 0.962(1) 1.340(1) 1.176(1)

θ0 [deg] a

θ see [deg] a

θ0 [deg] a

θ see [deg] a

107.6(10) 130.6(4)

108.2(1) 130.3(1)

107.5(14) 127.1(3)

107.9(1) 127.0(1)

OH

3 Molecules Containing One Carbon Atom

159

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

syn

anti

The rotational spectra of hydroxyoxomethyl were investigated in a supersonic jet by an FTMW spectrometer and microwave/millimeter-wave double resonance techniques in the frequency region between 22 and 210 GHz. The radicals were produced by an electrical discharge of a mixture of water vapor and carbon monoxide. Two conformers were observed. The r0 structure of each conformer was determined from the ground-state rotational constants of five isotopic species each (main, 13C, two 18O and D). The semiexperimental equilibrium structures r see were determined taking into account rovibrational corrections calculated with the CCSD(T)_ae/cc-pCVTZ harmonic and anharmonic (cubic) force fields. McCarthy MC, Martinez O, McGuire BA, Crabtree KN, Martin-Drumel MA, Stanton JF (2016) Isotopic studies of trans- and cis-HOCO using rotational spectroscopy: Formation, chemical bonding, and molecular structures. J Chem Phys 144(12) 124304/1-124304/11 [http://dx.doi.org/10.1063/1.4944070]

193 CAS RN: MGD RN: 216018 MW supported by ab initio calculations

Dichloromethane – argon (1/1) CH2ArCl2 Cs H

H Ar

Distance Rcm b

r0 [Å] a 3.608(1)

rs [Å] d 3.611

Angle

θ0 [deg] a

θs [deg] d

ϕ

c

16(5)

Cl

Cl

20.9

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit. Distance between Ar and the center-of-mass of the CH2Cl2 subunit. c Angle between Rcm and the c axis of the CH2Cl2 subunit. d Uncertainties were not given in the original paper. b

The rotational spectrum of the binary van der Waals complex of dichloromethane with argon was recorded by a molecular-beam FTMW spectrometer in the frequency region between 6 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl) under the assumption that the structural parameters of the dichloromethane subunit were not changed upon complexation.

160

3 Molecules Containing One Carbon Atom

Velino B, Evangelisti L, Caminati W, Fausto R (2010) Conformation, structure, quadrupole coupling constants and van der Waals potential energy surface of dichloromethane-Ar. J Mol Struct 976(1-3):136-140 194 CAS RN: 557-68-6 MGD RN: 426440 MW augmented by ab initio calculations

Bonds C–Br C–H C–I

r0 [Å] a 1.9261 1.0830 b 2.1313 b

Bond angles H–C–H Br–C–I Br–C–H

θ0 [deg] a

Bromoiodomethane CH2BrI Cs H

H

I

Br

107.66 113.53 107.27

Reprinted with permission. Copyright 2014 American Chemical Society.

a b

Uncertainties were not given in the original paper. Assumed at the value from CCSD(T)/aug-cc-pVTZ-PP calculations.

The rotational spectra of bromoiodomethane were recorded by a Balle-Flygare type FTMW spectrometer in the frequency region between 23 and 25 GHz. The millimeter-wave spectra were observed in the 122-175 and 199230 GHz range. The partial r0 structure was determined from the ground-state rotational constants of both Br isotopic species. Bailleux S, Duflot D, Taniguchi K, Sakai S, Ozeki H, Okabayashi T, Bailey WC (2014) Fourier transform microwave and millimeter-wave spectroscopy of bromoiodomethane, CH2BrI. J Phys Chem A 118(50):1174411750

195 CAS RN: 74-95-3 MGD RN: 970760 MW

Dibromomethane Methylene bromide CH2Br2 C2v H

Bonds C–H C–Br

rz [Å] a 1.0809(4) 1.9304(3)

Bond angles H–C–Br Br–C–Br

θz [deg] a

107.760 112.527(9)

Copyright 2009 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit.

Br

H

Br

3 Molecules Containing One Carbon Atom

161

The rz structure of the title molecule was refitted to the previously published ground-state rotational constants of five isotopic species. Kisiel Z, Kraśnicki A, Pszczółkowski L, Shipman ST, Alvarez-Valtierra L, Pate BH (2009) Assignment and analysis of the rotational spectrum of bromoform enabled by broadband FTMW spectroscopy. J Mol Spectrosc 257(2):177-186

196 CAS RN: 593-70-4 MGD RN: 745463 MW augmented by ab initio calculations

Bonds C–H C–F C–Cl

r see [Å] a 1.0847(2) 1.3595(3) 1.7641(3)

Bond angles H–C–H H–C–F H–C–Cl F–C–Cl

θ see [deg] a

Chlorofluoromethane CH2ClF Cs H

H

Cl

F

112.52(3) 109.15(12) 107.98(14) 110.03(1)

Reprinted by permission of Taylor & Francis Ltd. Final version received 10 April 2014

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure was determined from the previously published experimental groundstate rotational constants taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pV(T+d)Z harmonic and anharmonic (cubic) force fields. These results were used for benchmarking the CCSD(T)_ae method in conjunction with basis sets up to aug-cc-pwCV5Z quality. Vogt N, Demaison J, Rudolph HD (2014) Accurate equilibrium structures of fluoro- and chloroderivatives of methane. Mol Phys 112(22):2873-2883

197 CAS RN: 1333204-54-8 MGD RN: 213471 MW supported by ab initio calculations

Distance Cl...O

r0 [Å]a 3.028(3)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

Chlorotrifluoromethane – water (1/1) CH2ClF3O (see comment) F Cl

F F

O H

H

162 a

3 Molecules Containing One Carbon Atom

Parenthesized uncertainty in units of the last significant digit.

The spectrum was recorded in a pulsed supersonic jet by an FTMW spectrometer. The complex was identify only as a symmetric rotor, although MP2/6-311++G(d,p) calculations predicted only asymmetric rotor structures. The complex appears in the spectrum as a symmetric top due to the free rotation of the water subunit around the C3 axis of the CF3Cl subunit as predicted by ab initio. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 37 Cl, D2, D1 and 18O). Evangelisti L, Feng G, Écija P, Cocinero EJ, Castaño F, Caminati W (2011) The halogen bond and internal dynamics in the molecular complex of CF3Cl and H2O. Angew Chem 123(34):7953-7956; Angew Chem Int Ed 50(34):7807-7810

198 CAS RN: 593-71-5 MGD RN: 736000 MW augmented by ab initio calculations

Bonds C–I C–Cl C–H

r0 [Å] a 2.1485 1.7541 1.0832 b

Bond angles Cl–C–I Cl–C–H H–C–H

θ0 [deg] a

Chloroiodomethane CH2ClI Cs H

H

Cl

I

113.03 112.16 107.93 b

Copyright 2011 with permission from Elsevier.

a b

Uncertainties were not given in the original paper. Fixed to the value from CCSD(T)/cc-pVTZ calculation.

The rotational spectra were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the spectral region between 15 and 20 GHz. The millimeter/submillimeter-wave absorption spectrum between 199 and 646 GHz was studied at room temperature. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl). Bailleux S, Ozeki H, Sakai S, Okabayashi T, Kania P, Duflot D (2011) Fourier-transform microwave and submillimeter-wave spectroscopy of chloroiodomethane, CH2ICl. J Mol Spectrosc 270(1):51-55

199 CAS RN: 75-09-2 MGD RN: 822290 MW augmented by ab initio calculations

Dichloromethane Methylene chloride CH2Cl2 C2v

3 Molecules Containing One Carbon Atom

163 H

Bonds C–Cl C–H

r see [Å] a 1.76425(3) 1.0816(2)

Bond angles Cl–C–Cl H–C–H H–C–Cl

θ see [deg] a

H

Cl

Cl

112.166(3) 111.772(4) 108.237(10)

Reprinted by permission of Taylor & Francis Ltd. Final version received 10 April 2014

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure was determined from the previously published ground-state rotational constants taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/ccpV(T+d)Z harmonic and anharmonic (cubic) force fields. These results were used for benchmarking the CCSD(T)_ae method in conjunction with basis sets up to cc-pwCV5Z quality. Vogt N, Demaison J, Rudolph HD (2014) Accurate equilibrium structures of fluoro- and chloroderivatives of methane. Mol Phys 112(22):2873-2883

200 CAS RN: MGD RN: 468904 MW supported by ab initio calculations

Dichloromethane - neon (1/1)

Methylene chloride - neon CH2Cl2Ne

Cs

H

H Ne

a

Distance Rcm b

rs [Å]

Angle ϕc

θs [deg] a

Cl

Cl

3.45

25.4

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Uncertainty was not given in the original paper. Distance between Ne and the center-of-mass in the dichloromethane subunit. c Angle between Rcm and the c axis in the dichloromethane subunit. b

The rotational spectra of the binary van der Waals complex of dichloromethane with neon were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial rs structure was determined from the ground-state rotational constants of three isotopic species (main, 37 Cl and 22Ne). Favero LB, Maris A, Paltrinieri L, Caminati W (2015) Rotational spectrum of dichloromethane-Ne: internal dynamics and Cl quadrupolar hyperfine effects. J Phys Chem A 119(49):11813-11819

164

3 Molecules Containing One Carbon Atom

201 CAS RN: 373-53-5 MGD RN: 175818 MW augmented by ab initio calculations Bonds C–F C–I C–H

r see [Å] a 1.3610(16) 2.1396(16) 1.0831(4)

Bond angles F–C–I H–C–F H–C–I H–C–H

θ see [deg] a

Fluoroiodomethane CH2FI Cs

H

H

I

F

110.50(31) 109.74(24) 106.98(17) 112.84(7)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of fluoroiodomethane were recorded in the frequency region between 5 GHz and 1 THz by FTMW, a millimeter/submillimeter-wave and THz spectrometers. The 13C, D and D2 isotopic species were investigated. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ(-PP) harmonic and anharmonic (cubic) force fields. Puzzarini C, Cazzoli G, López JC, Alonso JL, Baldacci A, Baldan A, Stopkowicz S, Cheng L, Gauss J (2012) Rotational spectra of rare isotopic species of fluoroiodomethane: Determination of the equilibrium structure from rotational spectroscopy and quantum-chemical calculations. J Chem Phys 137(2):024310/1-024310/11

202 CAS RN: 75-10-5 MGD RN: 558307 MW augmented by ab initio calculations Bonds C–F C–H Bond angles F–C–F H–C–H H–C–F

r see [Å] a 1.35323(1) 1.08703(3)

θ see [deg] a

108.282(1) 113.442(9) 108.750(2)

Reprinted by permission of Taylor & Francis Ltd. Final version received 10 April 2014

Difluoromethane Methylene fluoride CH2F2 C2v H

F

H

F

3 Molecules Containing One Carbon Atom a

165

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure was determined from the previously published experimental groundstate rotational constants taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force constants. The results were used for benchmarking the CCSD(T)_ae method in conjunction with basis sets up to cc-pwCV5Z quality. Vogt N, Demaison J, Rudolph HD (2014) Accurate equilibrium structures of fluoro- and chloroderivatives of methane. Mol Phys 112(22):2873-2883

203 CAS RN: 1352347-43-3 MGD RN: 309192 MW

Trifluoroiodomethane – water (1/1) CH2F3IO Cs F

F

Distance O…I

r0 [Å] a 3.0527(15)

Angle

θ0 [deg] a

φ

b

O I

F

H

H

35.3(2)

Published by the PCCP Owner Societies.

a b

Parenthesized uncertainty in units of the last significant digit is 1σ value. Angle between O…I and the C2 axis of the water subunit.

The rotational spectrum of the binary complex of trifluoroiodomethane with water was recorded in a supersonic jet by a chirped-pulsed FTMW spectrometer in the frequency region between 7 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 18 O, D and D2). Stephens SL, Walker NR, Legon AC (2011) Molecular geometries of H2S⋅⋅⋅ICF3 and H2O⋅⋅⋅ICF3 characterized by broadband rotational spectroscopy. Phys Chem Chem Phys 13(47):21093-21101

204 CAS RN: 1352347-44-4 MGD RN: 308644 MW

Trifluoroiodomethane – hydrogen sulfide (1/1) CH2F3IS Cs F

Distance S…I

r0 [Å] a 3.5589(2)

Angle

θ0 [deg] a

φ

b

20.3(12)

Reproduced with permission from the PCCP Owner Societies.

F

F

S I

H

H

166 a b

3 Molecules Containing One Carbon Atom

Parenthesized uncertainty in units of the last significant digit is 1σ value. Angle between S…I and the C2 axis of the hydrogen sulfide subunit.

The rotational spectrum of the binary complex of trifluoroiodomethane with hydrogen sulfide was recorded in a supersonic jet by a chirped-pulsed FTMW spectrometer in the frequency region between 7 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main, D and D2). Stephens SL, Walker NR, Legon AC (2011) Molecular geometries of H2S⋅⋅⋅ICF3 and H2O⋅⋅⋅ICF3 characterized by broadband rotational spectroscopy. Phys Chem Chem Phys 13(47):21093-21101

205 CAS RN: 420-04-2 MGD RN: 598409 MW augmented by ab initio calculations

Cyanamide CH2N2 Cs

H N

Bonds H–N(1) N(1)–C C≡N(2)

r0 [Å] a 1.0041(7) 1.3470(35) 1.1620(37)

r (1) [Å] a m 1.0065(11) 1.3450(8) 1.1620(8)

Bond angles H–N–H N(1)–C≡N(2)

θ0 [deg] a

[deg] a θ (1) m

Dihedral angle

φc

115.65(14) 180 b

τ0 [deg] a

37.55(17)

112.62(14) 180 b

τ (1) [deg] a m 42.64(32)

r see [Å] a 1.0059(1) 1.3470(2) 1.1594(8)

C

N

H

θ see [deg] a

112.74(2) 178.22(17)

τ see [deg] a 42.78(9)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Assumed value. c Angle between N(1)–C and the H–N–H bisector. b

The rotational spectra of new isotopic species were recorded in the spectral region between 118 and 649 GHz by backward-wave-oscillator based spectrometers. structures were determined from the ground-state rotational constants of twelve isotopic species The r0 and r (1) m 13 (main, D2, C, two 15N, 15N2, 13C/D, two 15N/D, 13C/D2 and two 15N/D2). The semiexperimental equilibrium structure was obtained taking into account rovibrational corrections calculated with the CCSD(T)/cc-pVQZ harmonic and anharmonic (cubic) force fields. Kraśnicki A, Kisiel Z, Jabs W, Winnewisser BP, Winnewisser M (2011) Analysis of the mm- and submm-wave rotational spectra of isotopic cyanamide: New isotopologues and molecular geometry. J Mol Spectrosc 267(12):144-149

3 Molecules Containing One Carbon Atom

206 CAS RN: 56077-92-0 MGD RN: 396420 MW augmented by ab initio calculations

167

Dioxymethyl Peroxymethylene CH2O2 Cs O

O

Bonds O–O C=O C–H(1) C–H(2)

r0 [Å] a 1.345(3) 1.272(3) 1.094(1) 1.088(4)

Bond angles C=O–O O=C–H(1) O=C–H(2)

θ0 [deg] a

H

H

118.02(3) 117.96(56) 114.862 b

Reproduced with permission of AIP Publishing [a].

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Constrained to the value from CCSD(T)/aug-cc-pV5Z-F12 calculations.

The rotational spectra of dioxymethyl were investigated in a supersonic jet by a Balle-Flygare type FTMW spectrometer and FTMW-millimeter-wave double resonance technique in the frequency region between 4 and 70 GHz. The transient species were produced by a pulsed electrical discharge of dibromomethane with oxygen. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 18 O2, D2 and 18O2/D2). a. Nakajima M, Endo Y (2013) Determination of the molecular structure of the simplest Criegee intermediate CH2OO. J Chem Phys 139(10):01103/1-101103/4 [http://dx.doi.org/10.1063/1.4821165] MW augmented by ab initio calculations Bonds O–O C=O C–H(1) C–H(2) Bond angles C=O–O O=C–H(1) O–C–H(2)

r see [Å] a 1.3405(1) 1.2689(2) 1.0806(2) 1.0772(4)

θ see [deg] a

117.910(3) 118.65(2) 114.82(4)

Reprinted with permission. Copyright 2013 American Chemical Society [b].

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

168

3 Molecules Containing One Carbon Atom

The rotational spectra of dioxymethyl was investigated in a supersonic jet by FTMW and double resonance spectroscopy in the region between 20 and 88 GHz. The transient species was produced by an electrical discharge of mixture of methane with oxygen. Rotational constants of five further singly substituted isotopic species (13C, two 18O and two D) were determined. The semiexperimental equilibrium structure r see was obtained taking into account rovibrational corrections calculated with the CCSD(T)/ANO harmonic and anharmonic (cubic) force fields. b. McCarthy MC, Cheng L, Crabtree KN, Martinez O, Nguyen TL, Womack CC, Stanton JF (2013) The simplest Criegee intermediate (H2C=O-O): isotopic spectroscopy, equilibrium structure, and possible formation from atmospheric lightning. J Phys Chem Lett 4(23):4133-4139

207 CAS RN: 71946-83-3 MGD RN: 554714 MW augmented by ab initio calculations

Dihydroxymethylene CH2O2 Cs (syn-anti) HO

Bonds H–O(1) O(1)–C C–O(2) O(2)–H

r see [Å]a 0.976(3) 1.309(8) 1.335(8) 0.961(4)

Bond angles H–O(1)–C O(1)–C–O(2) C–O(2)–H

θ see [deg] a

OH

110.7(5) 107.30(2) 106.8(4)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission [a].

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The title compound was produced by a gas discharge of CO2 and H2. The rotational spectra were investigated by FTMW and microwave-millimeter wave double resonance spectroscopy. Only the anti-syn conformer, characterized by the antiperiplanar H–O(2)–C–O(1) and synperiplanar H–O(1)–C–O(2) torsional angles, was detected. This conformer was previously predicted by Schreiner et al. [b] to be higher in energy than the most stable conformer, anti-anti, by 0.9 kcal mol-1 at the CCSD(T)/cc-pVTZ level. The semiexperimental equilibrium structure was determined from the ground-state rotational constants of five isotopic species (main, two D, 13C and 18O2) taking into account rovibrational corrections calculated with the CCSD(T)/ANO1 harmonic and anharmonic (cubic) force fields. a. Womack CC, Crabtree KN, McCaslin L, Martinez O, Field RW, Stanton JF, McCarthy MC (2014) Gas-phase structure determination of dihydroxycarbene, one of the smallest stable singlet carbenes. Angew Chem 126(16):4173-4176; Angew Chem Int Ed 53(16):4089-4092 b. Schreiner PR, Reisenauer HP (2008) Spectroscopic identification of dihydroxycarbene. Angew. Chem 120(37):7179-7182; Angew Chem Int Ed 47(37):7071-7074

208 CAS RN: 40217-37-6 MGD RN: 116505

Carbon monoxide – water (1/1) CH2O2

3 Molecules Containing One Carbon Atom

169

IR C

Distance Rcm b

O

O

Cs H

H

a

r0 [Å] 3.9448

Reproduced with permission of AIP Publishing.

a b

Uncertainty was not given in the original paper. Distance between the centers of mass of the monomer subunits.

The rotationally resolved IR spectrum of the binary van der Waals complex of carbon monoxide with water was recorded in a supersonic jet by a tunable diode laser spectrometer in the region of the ν2 bending fundamental of D2O. The partial r0 structure was determined under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Zhu Y, Zheng R, Li S, Yang Y, Duan C (2013) Infrared spectra and tunneling dynamics of the N2-D2O and OCD2O complexes in the ν2 bend region of D2O. J Chem Phys 139(21):214309/1-214309/6

209 CAS RN: 463-79-6 MGD RN: 982954 MW augmented by ab initio calculations

Bonds C=O(1) C–O(2) C–O(3) O(2)–H O(3)–H

r0 [Å] a 1.18788(94) 1.3447(13) 1.3568(17) 0.968 b 0.968 b

Bond angles O(1)=C–O(2) O(1)=C–O(3) C–O(2)–H C–O(3)–H

θ0 [deg] a

Carbonic acid CH2O3 Cs (syn-anti) O

HO

OH

126.78(15) 122.94(12) 106.1 b 108.6 b

Reproduced with permission of AIP Publishing [a].

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. b Fixed to the value 0.005 Å longer than the value from CCSD(T)/cc-pVQZ calculation.

syn-anti

The rotational spectra of carbonic acid were investigated in a pulsed discharge by an FTMW spectrometer and microwave-millimeter-wave double resonance techniques in the frequency region between 5 and 65 GHz. The transient species was produced by an electrical discharge of carbon dioxide and water. Only one conformer characterized by synperiplanar and antiperiplanar O=C–C–H torsional angles, syn-anti, was observed, although it was predicted to be less stable than the syn-syn conformer by 1.74 kcal mol-1 (CCSD(T)/cc-pVQZ).

170

3 Molecules Containing One Carbon Atom

The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, two D and one D2). Mori T, Suma K, Sumiyoshi Y, Endo Y (2009) Spectroscopic detection of isolated carbonic acid. J Chem Phys 130(20):204308/1-204308/7 doi: 10.1063/1.3141405 MW augmented by ab initio calculations

C2v (syn-syn)

Bonds C=O(1) C–O(2) O–H

r0 [Å] a 1.20243(28) 1.33951(14) 0.968 b

Bond angles O(1)=C–O(2) C–O(2)–H

θ0 [deg] a

125.6941(95) 105.7 b

syn-syn

Reproduced with permission of AIP Publishing [b].

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Fixed to the value 0.005 Å longer than the value from CCSD(T)/cc-pVQZ calculation.

The rotational spectra of carbonic acid were investigated in a pulsed discharge by an FTMW spectrometer and microwave-millimeter-wave double resonance techniques in the frequency region between 6 and 39 GHz. The syn-syn conformer, predicted previously to be the most stable one (CCSD(T)/cc-pVQZ), was successfully detected. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D2). b. Mori T, Suma K, Sumiyoshi Y, Endo Y (2011) Spectroscopic detection of the most stable carbonic acid, ciscis H2CO3. J Chem Phys 134(4):044319/1-044319/6 doi: 10.1063/1.3532084

210 CAS RN: 473912-25-3 MGD RN: 456155 MW

Formic acid anhydride with sulfuric acid Formic sulfuric anhydride CH2O5S C1 O

Distances C(1)…S(5) C(1)–H(2) C(1)…H(9) S(5)...H(9) S(5)...H(2)

rs [Å] 2.594(5) 1.11(1) 2.62(1) 2.025(3) 3.513(2)

Reprinted with permission from AAAS.

a

O

a

Parenthesized uncertainties in units of the last significant digit.

O S

H

O

OH

3 Molecules Containing One Carbon Atom

171

The rotational spectra of formic sulfuric anhydride were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 12 GHz. The transient species were produced in a pulsed nozzle by the reaction of sulfur trioxide with formic acid. The partial rs structure was determined from the ground-state rotational constants of five isotopic species (main, 34 S, 13C and two D). Mackenzie RB, Dewberry CT, Leopold KR (2015) Gas phase observation and microwave spectroscopic characterization of formic sulfuric anhydride. Science 349(6243):58-61 doi: 10.1126/science.aaa9704 211 CAS RN: 92445-14-2 MGD RN: 956600 GED augmented by QC computations

Phosphorodibromidothious acid methyl ester Methyl dibromothiophosphite CH3Br2PS Cs (anti) C1 (gauche) Br

P–S P–Br P–Br' S–C C–H

ra [Å] a,b anti gauche 2.081(12) 2.093(12) 2.235(12) 2.245(12) 2.235(12) 2.215(12) 1.808(12) 1.816(12) 1.082(12) c 1.082(12) c

Angles

θh1 [deg] a,d

Bonds

P–S–C S–P–Br S–P–Br' Br–P–Br' S–C–H' S–C–H Dihedral angles C–S–P…lp e C–S–P–Br

anti 105.1(5) 103.4(5) 103.4(5) 99.8(5) 106.7(5) 110.3(5) anti 180.0 51.8 f

gauche 96.3(5) 103.1(5) 96.6(5) 102.4(5) 106.8(5) 111.0(5)

τh1 [deg]

P

Br

S

CH3

anti

gauche

gauche 55.1 f -75.2 g

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit include 3σ values, a systematic error of 0.1% and effects due to correlation of the refined parameters. b All bond lengths were refined in one group; their differences were assumed at the values from MP2/SDB-augcc-pVTZ(Br),aug-cc-pVTZ(S,P,C,H) computation. c Average value. d All bond angles were refined in one group; differences between refined parameters were adopted from computation as indicated above. e lp is an electron lone pair. f Assumed. g Adopted from computation as indicated above. The experimental data from Ref. [b] obtained at Tnozzle of 293 and 213 K at the long and short nozzle-to-film distances, respectively, were reanalyzed.

172

3 Molecules Containing One Carbon Atom

The title compound was found to exist as a mixture of anti and gauche conformers with the antiperiplanar and synclinal C–S–P…lp dihedral angles, respectively. The refined ratio of the conformers (in %) anti : gauche = 65(6) : 35(6) and theoretical prediction anti : gauche = 62 : 38 (B3PW91/6-311+G*) agree well. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from QC computation. a. Belyakov AV, Khramov AN, Naumov VN (2010) Molecular structure and conformational preferences of gaseous methylthiodibromophosphite, Br2PSCH3, studied by gas electron diffraction and quantum-chemical calculations. Russ J Gen Chem / Zh Obshch Khim 80 / 80 (11 / 11):2249-2258 / 1785-1794 b. Naumov VA, Kataeva OV, Sinyashin OG (1984) Molecular structure of methyl thiodichloroophosphite and methyl thiodibromophosphite. J Struct Chem (Engl Transl) /Zh Strukt Khim 25/25 (3/3):411-415/79-84

212 CAS RN: MGD RN: 216786 MW supported by ab initio calculations

Chlorodifluoromethane – water (1/1) CH3ClF2O Cs Cl O

Distances C…O Cl…H(2) H(1)…O Angles O...C–Cl H(2)–O...C O...H(1)–C H(2)–O...H(1)

H

H

r0 [Å] a 3.249(4) 2.749(13) b 2.332(3) b

F

F

θ0 [deg] a

83.2(5) 63.4(2) 139.7(2) b 76.0(1) b

Copyright 2011 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the binary complex was recorded in a supersonic jet by chirped-pulse and resonant cavity FTMW spectrometers in the spectral region between 5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main,37Cl, D, D2 and 37Cl/D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The barrier to internal rotation of the water subunit about its C2 axis was determined to be 195(5) cm-1. Bills BJ, Elmuti LF, Sanders AJ, Steber AL, Peebles RA, Peebles SA, Groner P, Neill JL, Muckle MT, Pate BH (2011) C–H⋅⋅⋅O interaction and water tunneling in the CHClF2-H2O dimer. J Mol Spectrosc 268(1-2):7-15

213 CAS RN: 420-59-7 MGD RN: 349245 MW supported by ab initio calculations

Chlorodifluoromethylsilane CH3ClF2Si Cs F

F

Si

Bonds

r0 [Å] a

rs [Å] a

H 3C

Cl

3 Molecules Containing One Carbon Atom

Si–C Si–F Si–Cl

1.814(9) 1.5825(7) 2.027(3)

1.817(2)

Bond angles F–Si–F C–Si–Cl F–Si–Cl

θ0 [deg] a

θs [deg] a

106.0(5) 112.9(4) 106.0(6)

173

2.019(5)

112.4(5)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title molecule was recorded by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The r0 and rs structure were determined from the ground-state rotational constants of the main, 13C, 37Cl, 29Si and 30 Si singly substituted as well as 37Cl/29Si and 37Cl/30Si doubly substituted isotopic species. The barrier to internal rotation of the methyl group was determined to be 468(3) cm-1. Seifert NA, Guirgis GA, Pate BH (2012) The molecular structure of methyl(difluoro)silyl chloride as determined by broadband microwave spectroscopy. J Mol Struct 1023:222-226

214 CAS RN: 1376312-12-7 MGD RN: 333597 MW supported by ab initio calculations

Chlorotrifluoromethane – ammonia (1/1) CH3ClF3N C3v F N H

Distance N…Cl

a

r0 [Å] 3.081(1)

a

rs [Å] 3.090(3)

Cl

F

H H

F

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of the complex was recorded in a pulsed supersonic jet by an FTMW spectrometer in the frequency range between 6 and 18.5 GHz. The partial structure was determined from available B0 rotational constants of six isotopic species (main, 37Cl, 15 N, D3, 37Cl/15N and 37Cl/D3). The subunits of the complex are held together due to a Cl…N halogen bond interaction. Feng G, Evangelisti L, Gasparini N, Caminati W (2012) On the Cl···N halogen Bond: A rotational study of CF3Cl···NH3 Chem Eur J 18:1364-1368

215 CAS RN: 5158-46-3 MGD RN: 444170 MW

Chloromethylzinc Methylzinc chloride CH3ClZn C3v H 3C

Zn

Cl

174

3 Molecules Containing One Carbon Atom

Bonds Zn–Cl Zn–C C–H

r0 [Å] a 2.23(7) 1.9201 b 1.105 b

Bond angles Zn–C–H H–C–H

θ0 [deg] a 110.2(5) 108.7 b

Copyright 2016 with permission from Elsevier.

a b

Parenthesized uncertainty in units of the last significant digit. Fixed to the experimental value of CH3ZnI.

The rotational spectrum of chloromethylzinc (1A1 electronic ground state) was recorded in a supersonic jet by FTMW and millimeter-wave direct absorption spectrometers in the spectral range between 10 and 296 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main, 66 Zn and 68Zn). Min J, Bucchino MP, Kilchenstein KM, Ziurys LM (2016) Rotational spectroscopy of ClZnCH3 (X1A1): Gasphase synthesis and characterization of a monomeric Grignard-type reagent. Chem Phys Lett 646(4):174-178

216 CAS RN: 14684-24-3 MGD RN: 129181 GED augmented by QC computations

Phosphorodichloridothious acid methyl ester Methyl dichlorothiophosphite CH3Cl2PS Cs (anti) C1 (gauche) Cl

Bonds P–S P–Cl P–Cl' S–C C–H Bond angles P–S–C S–P–Cl S–P–Cl' Cl–P–Cl' S–C–H' S–C–H Dihedral angles C–S–P–lp e C–S–P–Cl

a,b

anti 2.059(5) 1 2.047(5) 1 2.047(5) 1 1.765(11) 2 1.116 c,d

ra [Å] gauche 2.070(5) 1 2.053(5) 1 2.030(5) 1 1.773(11) 2 1.116 c,d

θh1 [deg] a,b

anti 103.7(3) 3 102.2(3) 3 102.2(3) 3 98.2(3) 3 106.0 d 109.8 d

anti 180.0 d 50.7 d

gauche 95.3(3) 3 102.2(3) 3 96.3(3) 3 100.7(3) 3 106.2 d 110.4 c,d

τh1 [deg]

gauche 53.8 d -77.4 d

Copyright 2009 with permission from Elsevier.

P Cl

S

CH3

anti

gauche

3 Molecules Containing One Carbon Atom

175

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/aug-cc-pVTZ computation. c Average value. d Assumed at the value from computation as indicated above. e lp is a lone pair of electrons. b

The GED experiment was carried out at Tnozzle=293 K. The title compound was found to exist as a mixture of the anti and gauche conformers characterized by the antiperiplanar and synclinal conformations of the C–S–P…lp unit, respectively. The ratio of the conformers was refined to be (in %) anti : gauche = 68(12) : 32(12). Approximately the same ratio was predicted at the B3PW91/6-311+G* level of theory (anti : gauche = 65:35 (in %)). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from MP2 aug-cc-pVTZ computation. Belyakov AV, Khramov AN, Naumov VA (2010) Molecular structure and conformational preferences of methylthiodichlorophosphite, Cl2PSCH3, as studied by gas electron diffraction and quantum-chemical calculations. J Mol Struct 978 (1-3):4-10

217 CAS RN: 1346678-37-2 MGD RN: 309407 MW

Trifluoroiodomethane – ammonia (1/1) CH3F3IN C3v F

r0 [Å] 3.997(1) 3.039(1)

Angles

θ0 [deg] a

α γd

N H

a

Distances Rcm b N…I

c

F

F

I

H H

20.3(12) 4.12(37)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Distance between centers of mass in both monomer subunits. c Angular oscillation of the ammonia subunit. d Angular oscillation of the trifluoroiodomethane subunit. b

The rotational spectra of the binary complex of trifluoroiodomethane with ammonia were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.7 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 15N) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Stephens SL, Walker NR, Legon AC (2011) Internal rotation and halogen bonds in CF3I⋅⋅⋅NH3 and CF3I⋅⋅⋅N(CH3)3 probed by broadband rotational spectroscopy. Phys Chem Chem Phys 13(46):20736-20744

176

3 Molecules Containing One Carbon Atom

218 CAS RN: 18815-73-1 MGD RN: 404865 MW supported by DFT calculations

Bonds Zn–I Zn–C C–H

r0 [Å] a 2.4076(2) 1.9201(2) 1.105(9)

Bond angles Zn–C–H H–C–H

θ0 [deg] a

Iodomethylzinc Methylzinc iodide CH3IZn C3v

H H

Zn

I

H

110.2(5) 108.7(5)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of methylzinc iodide were recorded in the millimeter-wave region between 256 and 293 GHz. The transient species (1A1 electronic ground state) was produced by a DC discharge of zinc vapor and iodomethane. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 66Zn, 13 C and D3). Bucchino MP, Young JP, Sheridan PM, Ziurys LM (2014) Structural determination and gas-phase synthesis of monomeric, unsolvated IZnCH3 (X1A1): a model organozinc halide. J Phys Chem A 118(47):11204-11210

219 CAS RN: 187278-70-2 MGD RN: 145550 MW

Hydrogen cyanide – dihydrogen (1/1) CH3N C∞ v H

Distance Rcm b

r0 [Å] a ortho-H2 3.9617(5)

C

N

H

H

para-H2 4.1589(13)

Copyright 2012 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the HCN and H2 subunits.

ortho

para

The rotational spectrum of the binary complex was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency range between 4 and 40 GHz. Two conformers with ortho- and para-H2 were identified in the spectrum. The r0 parameters of the conformers were determined under the assumption that the structures of the monomer subunits were not changed upon complexation.

3 Molecules Containing One Carbon Atom

177

Ishiguro M, Harada K, Tanaka K, Tanaka T, Sumiyoshi Y, Endo Y (2012) Fourier-transform microwave spectroscopy of the H2-HCN complex. Chem Phys Lett 554:33-36

220 CAS RN: 75-12-7 MGD RN: 472260 MW supported by ab initio calculations

Bonds C=O C–N N–H(1) N–H(2) C–H Bond angles O=C–N H(1)–N–C H(2)–N–C H–C–N

r0 [Å]a 1.2165(33) 1.3630(32) 0.9917(31) 1.0015(26) 1.1018(25)

Formamide CH3NO Cs O

H

NH2

θ0 [deg] a

124.256(71) 120.61(32) 118.08(16) 114.8(18)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission [a].

a

Parenthesized uncertainties in units of the last significant digit.

The r0 structure of the title molecule was re-determined using the previously published ground-state rotational constants. a. Blanco S, Pinacho P, López JC (2016) Hydrogen-bond cooperativity in formamide2-water: A model for watermediated interactions. Angew Chem 128(32):9477-9481; Angew Chem Int Ed 55(32):9331-9335 MW augmented by ab initio calculations Bonds C=O C–N C–H N–H(2) N–H(1)

r see [Å] a 1.212(2) 1.354(2) 1.097(3) 1.017(2) 1.008(2)

Bond angles O=C–N H–C–N C–N–H(2) C–N–H(1)

θ see [deg] a 124.2(5) 112.4(13) 120.5(2) 119.9(1)

Reprinted with permission. Copyright 2016 American Chemical Society [b].

Cs

178 a

3 Molecules Containing One Carbon Atom

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see was determined from the previously published experimental ground-state rotational constants of all singly and one multiply substituted isotopic species taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force constants. b. Alessandrini S, Puzzarini C (2016) Structural and energetic characterization of prebiotic molecules: The case study of formamide and its dimer. J Phys Chem A 120(27):5257-5263

221 CAS RN: MGD RN: 115926 MW, IR supported by ab initio calculations

Carbonyl sulfide – ammonia (1/1) CH3NOS C3v N

O

C

S

H

H H

Distances S…N Rcm b

r0 [Å] a 3.3233(2) 4.3607(2)

Angle

θ0 [deg] a

α

c

25.23(4)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Distance between centers of mass of the monomer subunits. c Angular oscillation of the ammonia subunit. b

The rotational spectra of the binary complex of carbonyl sulfide with ammonia were recorded by a pulsed-nozzle FTMW spectrometer in the frequency region between 6.5 and 18 GHz and by a pulsed-nozzle multipass absorption spectrometer, based on a quantum cascade laser spectrometer at about 1638 cm-1. The partial r0 structure was determined under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Liu X, Xu Y (2011) Infrared and microwave spectra of the acetylene-ammonia and carbonyl sulfide-ammonia complexes: a comparative study of a weak C–H⋅⋅⋅N hydrogen bond and an S⋅⋅⋅N bond. Phys Chem Chem Phys 13(31):14235-14242

222 CAS RN: MGD RN: 430730 MW supported by ab initio calculations

Formic acid – nitric acid (1/1) CH3NO5 Cs O

O N

Distances

r0 [Å]

a

H

OH

HO

O

3 Molecules Containing One Carbon Atom

O(5)…H(8) O(9)…H(4)

179

1.686(17) 1.813(21)

Angles θ0 [deg] a O(5)…H(8)–O(6) 173.4(21) O(3)–H(4)…O(9) 173.29(85) Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the binary complex of formic acid with nitric acid were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 4.7 and 15 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 13C, 15N, three D and 15N/D) for the intermolecular H-bonds accounting for the changes in the monomer structures upon complexation. Mackenzie RB, Dewberry CT, Leopold KR (2014) The formic acid-nitric acid complex: microwave spectrum, structure, and proton transfer. J Phys Chem A 118(36):7975-7985

223 CAS RN: 2143-68-2 MGD RN: 109538 UV

Bonds C–O C–H Bond angle H–C–H

Methoxy CH3O C3v

H H

r0 [Å] a 1.36039(8) 1.10697(9)

O

H

θ0 [deg] a

107.76(1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotationally resolved laser-induced fluorescence and stimulated emission pumping spectra of the perdeuterated radical (2E electronic ground state) were investigated in a supersonic jet. The radical was produced by photolysis of perdeuterated methyl nitrite. The r0 structure was determined from the obtained ground-state rotational constants together with the previously published data for the main isotopic species. Liu J, Chen MW, Melnik D, Miller TA, Endo Y, Hirota E (2009) The spectroscopic characterization of the methoxy radical. II. Rotationally resolved A2A1-X2E electronic and X2E microwave spectra of the perdeuteromethoxy radical CD3O. J Chem Phys 130(7):074303/1-074303/11 https://doi.org/10.1063/1.2955739

224

Hydroxyoxomethyl – water (1/1)

180

3 Molecules Containing One Carbon Atom

CAS RN: 255883-88-6 MGD RN: 342453 MW augmented by ab initio calculations

CH3O3 Cs O

C a

Distances O(3)…H(1) C–O(1) C=O(2) O(1)–H(1) O(3)–H(2)

r0 [Å] 1.794 1.332 b 1.188 b 0.981 b 0.963 b

Angles O(1)–C=O(2) H(1)–O(1)–C H(2)–O(3)–H(2) O(1)–H(1)…O(3)

θ0 [deg]

αc

O

OH

H

H

128.3 b 108.2 b 105.1 b 179.3 b 43.3 b

Reproduced with permission of AIP Publishing.

a

Uncertainty was not given in the original paper. Constrained to CCSD(T)/aug-cc-pVTZ value. c Angle between the hydrogen bond and the C2 axis of the water subunit. b

The rotational spectra of the binary complex of the hydroxyoxomethyl radical with water were investigated in a supersonic jet by Balle-Flygare type FTMW and millimeter-wave FTMW double resonance spectrometers in the frequency region between 4 and 30 GHz. The transient radicals were produced in a pulsed discharge of carbon monoxide and water. Only the anti conformer with the antiperiplanar H(1)–O(1)–C=O dihedral angle was investigated. The partial r0 structure was determined from the ground-state rotational constants. The remaining structural parameters were constrained to the ab initio values (see above). Oyama T, Nakajima M, Sumiyoshi Y, Endo Y (2013) Pure rotational spectroscopy of the H2O-trans-HOCO complex. J Chem Phys 138(20):204318/1-204318/8 [http://dx.doi.org/10.1063/1.4807749]

225

(Chloromethyl)fluorosilane

CAS RN: 151479-79-7

MGD RN: 469279 MW supported by ab initio calculations

CH4ClFSi

Cs F

Bonds Si–F C–Cl Si–C C–H Si–H Bond angles F–Si–C

a

r0 [Å] 1.608(3) 1.771(3) 1.884(3) 1.091(2) 1.469(2)

θ0 [deg] a 108.9(5)

Cl

Si H2

3 Molecules Containing One Carbon Atom

Cl–C–Si H–C–Si H–Si–C H–C–H H–Si–H Cl–C–H F–Si–H

181

104.9(5) 113.5(5) 109.7(5) 108.3(5) 112.1(5) 108.2(5) 108.1(5)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of (chloromethyl)fluorosilane was recorded in a pulsed supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 26 GHz. Only one conformer characterized by the antiperiplanar Cl–C–Si–F dihedral angle was observed. The r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 13C, 37 Cl, 29Si and 30Si). Guirgis GA, Sawant DK, Brenner RE, Deodhar BS, Seifert NA, Geboes Y, Pate BH, Herrebout WA, Hickman DV, Durig JR (2015) Microwave, r0 structural parameters, conformational stability, and vibrational assignment of (chloromethyl)fluorosilane. J Phys Chem A 119(47):11532-11547

226 CAS RN: 7237-08-3 MGD RN: 124578 GED augmented by ab initio computations

Bonds P–C C–Cl P–H C–H

(Chloromethyl)phosphine CH4ClP Cs (I) C1 (II)

rh1 [Å] a Cs C1 1.868(6) b 1.879(6) b b 1.787(5) 1.784(5) b c,d 1.427(5) 1.427(5) c,d c 1.102(6) 1.102(6) c

Bond angles H–P–H C–P–H H–C–H P–C–H P–C–Cl

Cl–C–P…X1 f X1…P–C…X2 f

Cs 0.0 180.0

C1 94.7(10) c,d 97.0(9) c,d 106.0(9) c,d 110.9(10) c,d 106.9(7) e

τh1 [deg] a

C1 -120.9(15) c 59.5(15) c

Reprinted with permission. Copyright 2009 American Chemical Society [a].

a

PH2

I

θh1 [deg] a

Cs 94.7(10) c,d 97.0(9) c,d 106.0(9) c,d 108.4(10) 115.2(1) e

Dihedral angles

Cl

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit.

II

182

3 Molecules Containing One Carbon Atom

b

Derived from the refined average value of r(P–C) and r(C–Cl) and the differences between these distances restrained to the values from MP2/6-311++G** computation. c Restrained to the value from computation as indicated above. d Average value. e Dependent parameter. f X1 and X2 are the bisectors of the H–P–H and H–C–H angles, respectively. According to results of previous GED study [b], the title molecule exists as a mixture of two conformers, I and II, with Cs and C1 point-group symmetry, respectively. In the conformer I, the Cl–C–P–H dihedral angles are ±synclinal, whereas in the conformer II, one Cl–C–P–H dihedral angle is antiperiplanar and the other one is close to synclinal. The GED experiments were carried out at 273 and 293 K at the long and short nozzle-to-plate distances, respectively. The ratio of the conformers was determined to be Cs : C1 = 84(3) : 16(3) (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/6-311++G** computations. a. Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48(17):8603-8612 b. Brain PT, Rankin DWH, Robertson HE, Downs AJ, Greene TM, Hoffman M, Schleyer PvR (1995) Molecular structure of 1-(dichloroboryl)pentaborane(9), in the gas phase as determined by electron diffraction and supported by theoretical calculations. J Mol Struct 352:135-144

227 CAS RN: 62-56-6 MGD RN: 888960 MW augmented by ab initio calculations

Thiourea CH4N2S C2 S

Bonds C=S C–N N–H(1) N–H(2)

r0 [Å] a 1.6493(21) 1.3680(13) 0.9511(92) 0.9992(65)

r see [Å] a 1.65455(18) 1.35940(11) 1.00308(90) 1.00598(46)

Bond angles N–C=S C–N–H C–N–H(1)

θ0 [deg] a

θ see [deg] a

122.84(82) 119.5(11)

H2N

NH2

122.737(7) 114.934(85)

Reprinted with permission. Copyright 2012 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The CCSD(T)/cc-pVTZ calculations predicted the existence of the C2 conformer only. The r0 structure of this conformer was determined from the previously published experimental ground-state rotational constants. The semiexperimental equilibrium structure r see was obtained taking into account rovibrational corrections calculated with the MP2/aug-cc-pVTZ harmonic and anharmonic (cubic) force fields. Puzzarini C (2012) Molecular structure of thiourea. J Phys Chem A 116(17):4381-4387

3 Molecules Containing One Carbon Atom

228 CAS RN: MGD RN: 416679 MW augmented by ab initio calculations

183

Dioxymethyl – water (1/1) Peroxymethylene – water (1/1) CH4O3 C1 O O

Distances O(1)…H(3) H(1)…O(3) O(1)–O(2) O(2)=C(1) C(1)–H(1) C(1)–H(2) O(3)–H(3) O(3)–H(4)

r0 [Å] a 1.9096(9) 2.123 1.367 1.268 b 1.086 b 1.082 b 0.975 b 0.960 b

Angles O(2)–O(1)…H(3) O(1)–O(2)=C(1) O(2)=C(1)–H(1) O(2)=C(1)–H(2) O(1)…H(3)–O(3) H(3)–O(3)–H(4)

θ0 [deg] a

Dihedral angle H(4)–O(3)–H(3)…O(1)

τ0 [deg] a

O H

H

H

H

110.11(5) 118,7 b 120.3 b 113.7 b 155.3 b 106.2 b

25(1)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainty in units of the last significant digit. Constrained to the value from CCSD(T)/aug-cc-pVTZ calculation.

The rotational spectra of the binary complex of dioxymethyl with water were recorded in a supersonic jet by Balle-Flygare type FTMW and Fourier transform microwave-millimeter-wave double resonance spectrometers in the frequency region between 6 and 65 GHz. The transient species were produced by an electrical discharge of a mixture of diiodomethane, water and oxygen. The partial r0 effective structure was obtained from the ground-state rotational constants of isotopic species (main and D2) assuming the remaining structural parameters at the ab initio values (see footnote above). Nakajima M, Endo Y (2014) Spectroscopic characterization of the complex between water and the simplest Criegee intermediate CH2OO. J Chem Phys 140(13):134302/1-134302/5 [http://dx.doi.org/10.1063/1.4869696]

229 CAS RN: 22636-56-2 MGD RN: 157616 MW

Bonds

r0 [Å] a

Hydromethylzinc CH4Zn C3v

184

3 Molecules Containing One Carbon Atom

H–Zn Zn–C C–H

1.5209(1) 1.9281(2) 1.140(9)

Bond angles Zn–C–H H–C–H

θ0 [deg] a

H H

H

Zn

H

110.2(3) 108.7(3)

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

The rotational spectra of hydromethylzinc (1A1 electronic ground state) were recorded by a pulsed-jet BalleFlygare type FTMW and millimeter/submillimeter-wave direct absorption spectrometers in the frequency regions 18-41 and 332-516 GHz. The transient species were produced by a DC discharge of evaporated zinc with methane. The r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 66Zn, 67 Zn, 68Zn, 13C, D and D/66Zn). Flory MA, Apponi AJ, Zack LN, Ziurys LM (2010) Activation of methane by zinc: Gas-phase synthesis, structure, and bonding of HZnCH3. J Amer Chem Soc 132(48):17186-17192

230 CAS RN: 7570-21-0 MGD RN: 123000 MW augmented by ab initio calculations

Bonds C–Si Si–H(1) Si–H(2) C–H C–Br

r0 [Å] a 1.886(3) 1.484(2) 1.479(2) 1.091(2) 1.946(3)

Bond angles Si–C–Br C–Si–H(1) C–Si–H(2) H(1)–Si–H(2) H(2)–Si–H(2ꞌ) Si–C–H Br–C–H H–C–H

θ0 [deg] a

Dihedral angles H(2)–Si–C…Br H–C–Si…Br

τ0 [deg] a

109.1(5) 108.4(5) 109.3(5) 109.8(5) 110.3(5) 112.1(5) 107.5(5) 108.2(5)

60.3(5) 119.0(5)

Reprinted with permission. Copyright 2010 American Chemical Society.

(Bromomethyl)silane CH5BrSi Cs Br

SiH3

3 Molecules Containing One Carbon Atom a

185

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure of the title molecule was determined by fitting the MP2/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of two isotopic species. Durig JR, Panikar SS, Groner P, Nanaie H, Bürger H, Moritz P (2010) Microwave spectrum, r0 structure, dipole moment, barrier to internal rotation, and ab initio calculations for fluoromethylsilane. J Phys Chem A 114(12):4131-4137

231 CAS RN: 184170-23-8 MGD RN: 454186 MW augmented by ab initio calculations

Chloromethane - water (1/1) Methyl chloride – water (1/1) CH5ClO Cs H

Distances Cl(2)…O(3) Cl(2)…H(5) H(4)…O(3)

r0 [Å] a 3.344(2) 2.638(2) b 2.501(2) b

Angles C(1)–Cl(2)…O(3) Cl(2)…O(3)…X c C(1)–Cl(2)…H(5) C(1)–H(4)…O(3) Cl(2)…H(5)–O(3)

θ0 [deg] a

Cl

H

O H

H

H

74.2(1) 89(2) 87(2) b 132.5(1) b 131(2) b

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c X is a dummy atom on the C2 axis of the water subunit. b

The rotational spectrum of the title complex was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency range between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of the four isotopic species (main, 37Cl, 18O and D2); the remaining structural parameters were fixed to the MP2/6-311++G(2d,2p) values. The two subunits of the complex are linked by two weak hydrogen bonds. The barrier to internal rotation of water about its symmetry axis was determined to be V2 = 320(10) cm-1. Gou Q, Spada L, Lòpez JC, Grabow JU, Caminati W (2015) Chloromethane-water adduct: rotational spectrum, weak hydrogen bonds, and internal dynamics. Chem Asian J 10(5):1198-1203

232 CAS RN: 10112-09-1 MGD RN: 616327 MW augmented by ab initio calculations

(Chloromethyl)silane CH5ClSi Cs

186

3 Molecules Containing One Carbon Atom

Bonds C–Si Si–H(1) Si–H(2) C–H C–Cl

r0 [Å] a 1.886(3) 1.484(2) 1.478(2) 1.091(2) 1.791(3)

Bond angles Si–C–Cl C–Si–H(1) C–Si–H(2) H(1)–Si–H(2) H(2)–Si–H(2ꞌ) Si–C–H Cl–C–H H–C–H

θ0 [deg] a

Dihedral angles H(2)–Si–C–Cl H–C–Si…Cl

τ0 [deg] a

SiH3

Cl

109.3(5) 108.2(5) 109.3(5) 109.9(5) 110.2(5) 111.3(5) 108.6(5) 107.7(5)

60.3(5) 119.9(5)

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure was determined by fitting the MP2/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of two isotopic species. Durig JR, Panikar SS, Groner P, Nanaie H, Bürger H, Moritz P (2010) Microwave spectrum, r0 structure, dipole moment, barrier to internal rotation, and ab initio calculations for fluoromethylsilane. J Phys Chem A 114(12):4131-4137

233 CAS RN: 10112-08-0 MGD RN: 213643 MW augmented by ab initio calculations

(Fluoromethyl)silane CH5FSi Cs F

Bonds C–Si C–F Si–H(4) Si–H(5) C–H(7)

r0 [Å] a 1.8942(57) 1.4035(55) 1.4779(63) 1.4738(7) 1.0911(12)

r see [Å] a 1.8856(25) 1.4007(24) 1.4784(28) 1.4725(3) 1.0905(5)

Bond angles F–C–Si H(4)–Si–C H(5)–Si–C

θ0 [deg] a

θ see [deg] a

109.58(14) 107.28(28) 109.32(10)

109.45(6) 108.05(12) 109.96(4)

SiH3

3 Molecules Containing One Carbon Atom

H(7)–C–Si H(5)–Si–H(6) H(4)–Si–H(5) H(7)–C–H(8) H(7)–C–F Dihedral angles H(5)–Si–C…H(4) H(7)–C–Si…F

187

111.69(35) 110.15(18) 110.35(16) 107.33(23) 108.21(39)

111.80(15) 110.08(8) 109.38(7) 108.00(10) 107.81(17)

τ0 [deg] a

τ see [deg] a

119.67(11) 119.90(21)

119.32(5) 119.38(9)

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of (fluoromethyl)silane were recorded by a Stark-modulated microwave spectrometer in the frequency region between 18 and 40 GHz. The r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 13C, three D and two D2). The semiexperimental equilibrium structure r see was obtained taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/6-31G(d) harmonic and anharmonic (cubic) force fields. Durig JR, Panikar SS, Groner P, Nanaie H, Bürger H, Moritz P (2010) Microwave spectrum, r0 structure, dipole moment, barrier to internal rotation, and ab initio calculations for fluoromethylsilane. J Phys Chem A 114(12):4131-4137

234 CAS RN: 74-89-5 MGD RN: 392340 GED augmented by ab initio computations

Bonds C–N C–H N–H

ra3,1 [Å] a,b 1.434(3) 1.112(7) c,d 1.025(10) d

Bond angles H–N–H N–C–H H–C–H N–C–H(s) e N–C–H(a) e

θa3,1 [deg] a,b

Methanamine Methylamine CH5N Cs H H

NH2 H

106.4(11) d 109.5(7) c,d 110.0(11) d 111.4(7) f 107.6(7) f

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Difference between the C–N bond lengths in trihydro(methanamine)boron and methylamine was assumed at the value from ab initio computation. All remaining parameters of methylamine were assumed to be equal to those in trihydro(methanamine)boron. c Average value. d Restrained to the value from MP2_full/aug-cc-pVQZ computation. e H(s) and H(a) are the atoms lying in symmetry plane and out of symmetry plane, respectively. b

188 f

3 Molecules Containing One Carbon Atom

Dependent parameter.

The GED experiment was carried out at Tnozzle ≈ 382 K. The trihydro(methanamine)boron sample was found to be dissociated. The best fit to the experimental intensities was obtained by accounting for two dissociation products, methylamine and diborane (B2H6). The fraction of the non-dissociated trihydro(methanamine)boron was determined to be 0.67(3). Vibrational corrections to the experimental internuclear distances, ∆ra3,1 = ra − ra3,1, were calculated from the HF/6-31G* quadratic and cubic force fields taking into account non-linear kinematic effects. Aldridge S, Downs AJ, Tang CY, Parsons S, Clarke MC, Johnstone RDL, Robertson HE, Rankin DWH, Wann DA (2009) Structures and aggregation of the methylamine-borane molecules, MenH3-nN·BH3 (n=1-3), studied by X-ray diffraction, gas-phase electron diffraction, and quantum chemical calculations. J Am Chem Soc 131 (6):2231-2243 235 CAS RN: 1722-33-4 MGD RN: 112752 GED augmented by ab initio computations

Trihydro(methanamine)boron Methylamine – borane (1/1) CH8BN Cs H 3C

Bonds C–H N–H B–H C–N N–B

ra3,1 [Å] a 1.112(7) b,c 1.025(10) c 1.208(10) b,c 1.449(3) 1.602(7)

Bond angles H–N–H N–C–H H–C–H N–B–H H–B–H X…N–C d X…N–B d N–C–H(1) N–C–H(2) N–B–H(4) N–B–H(3) B–N–C

θa3,1 [deg] a

NH2 BH3

106.4(11) c 109.5(7) b,c 110.0(11) c 103.9(9) b,c 113.5(11) c 125.9(8) c 122.7(8) c 111.4(7) e,f 107.6(7) e,f 103.6(10) e,g 104.2(9) e,g 111.4(5) e

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Average value. c Restrained to the value from MP2_full/aug-cc-pVQZ computation. d X is the bisector of the H–N–H angle. e Dependent parameter. f Difference between the N–C–H bond angles was restrained to the value from computation as indicated above. g Difference between the N–B–H bond angles was restrained to the value from computation as indicated above. b

The GED experiment was carried out at Tnozzle ≈ 382 K. The title compound was found to be partially dissociated. The best fit to the experimental intensities was obtained by accounting for two dissociation products,

3 Molecules Containing One Carbon Atom

189

methylamine (CH3NH2) and diborane (B2H6). The fraction of the non-dissociated molecules was determined to be 0.67(3). Vibrational corrections to the experimental internuclear distances, ∆ra3,1 = ra − ra3,1, were calculated from the HF/6-31G* quadratic and cubic force fields taking into account non-linear kinematic effects. Aldridge S, Downs AJ, Tang CY, Parsons S, Clarke MC, Johnstone RDL, Robertson HE, Rankin DWH, Wann DA (2009) Structures and aggregation of the methylamine-borane molecules, MenH3-nN·BH3 (n=1-3), studied by X-ray diffraction, gas-phase electron diffraction, and quantum chemical calculations. J Am Chem Soc 131 (6):2231-2243

236 CAS RN: 186689-10-1 MGD RN: 525663 MW supported by ab initio calculations

Formamide – water (1/3) CH9NO4 C1 O

O

Distances C(2)–N(3) N(3)…O(4) O(4)…O(5) O(6)...O(5) O(6)–H(1) C(2)...O(6) C(2)...H(1) O(4)–H(9) O(5)...H(9) O(5)–H(3) O(6)...H(3) N(3)–H(5)

rs [Å] a 1.305(19) 2.8764(24) 2.7034(93) 2.766(10) 1.0476(71) 3.788(10) 2.779(13) 0.8115(30) 1.8936(98) 0.957(13) 1.8253(41) 0.9231(22)

Bond angles C(2)–N(3)–H(5) C(2)–N(3)…O(4) N(3)…O(4)…O(5) N(3)…O(4)–H(9) O(4)–H(9)…O(5) H(9)…O(5)–H(3) O(5)–H(3)…O(6) H(3)…O(6)–H(1) O(4)…O(5)…O(6) O(5)…O(6)–H(1) O(5)…O(6)…C(2) O(6)…C(2)–N(3) N(3)–C(2)…H(1)

θs [deg] a

Dihedral angles C(2)–N(3)…O(4)…O(5) N(3)…O(4)….O(5)…O(6) O(4)…O(5)…O(6)-H(1) O(4)…O(5)…O(6)…C(2) O(5)…O(6)–H(1)…C(2) O(5)…O(6)…C(2)–N(3) O(6)…C(2)–N(3)…O(4) C(2)…O(6)…O(4)…O(5) C(2)–N(3)…O(4)…O(6)

τs [deg] a

119.32(37) 129.15(37) 113.05(20) 116.18(29) 175.53(45) 99.93(58) 166.9(19) 116.03(23) 93.688(79) 113.34(28) 99.12(31) 98.313(97) 103.20(12)

-25.9(10) 25.38(36) -19.08(11) -18.93(31) 0.6(41) 9.65(74) 7.94(92) 158.06(36) -7.80(90)

H H

NH2

H

3

190

3 Molecules Containing One Carbon Atom

Reprinted with permission. Copyright 2017 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the quarternary complex of formamide with water were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 13 GHz. The rs structure was determined from the ground-state rotational constants of ten isotopic species (main, 15N, 13C, three 18O and four D). Blanco S, Pinacho P, López J. C (2017) Structure and dynamics in formamide-(H2O)3: A water pentamer analogue. J Phys Chem Lett 8(24):6060-6066

237 CAS RN: MGD RN: 358696 IR

Carbon disulfide – helium (1/1) CHeS2 C2v S

Distance C…He

r0 [Å] a 3.817

Angle

θ0 [deg] a

ϕ

b

He

S

C

79.0

Copyright 2012 with permission from Elsevier.

a b

Uncertainty was not given in the original paper. The effective angle between the S=C=S axis and Rcm.

The rotationally resolved mid-IR spectrum of the binary van der Waals complex was recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the region of the CS2 ν3 fundamental and ν1+ν3 combination bands at 1535 and 2185 cm-1, respectively. The complex was found to have a T-shaped structure. The equilibrium structure is suggested to be of C2v symmetry. The r0 structure was determined under the assumption that the structural parameters of the carbon disulfide subunit were not changed upon complexation. Mivehvar F, Lauzin C, McKellar ARW, Moazzen-Ahmadi N (2012) Infrared spectra of rare gas-carbon disulfide complexes: He-CS2, Ne-CS2, and Ar-CS2. J Mol Spectrosc 281:24-27

238 CAS RN: MGD RN: 410085 MW supported by DFT calculations

Carbon monoxide – sulfur trioxide – krypton (1/1/1) CKrO4S C3v O

C

Distances S…Kr

a

r0 [Å] 3.488(6)

O

Kr

S O

O

3 Molecules Containing One Carbon Atom

S…C

191

2.871(9)

Reproduced with permission of AIP Publishing. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the ternary van der Waals complex of carbon monoxide with sulfur trioxide and krypton were recorded in a supersonic jet by a pulsed-jet FTMW spectrometer in the frequency region between 3.2 and 5.7 GHz. The partial r0 structure was obtained from the ground-state rotational constants of eight isotopic species (main, 13C, 82Kr, 83 Kr, 86Kr, 82Kr/13C, 83Kr/13C and 86Kr/13C) under the assumption that the structural parameters of the carbon monoxide and sulfur trioxide subunits were not changed upon complexation. Mackenzie RB, Timp BA, Mo Y, Leopold KR (2013) Effects of a remote binding partner on the electric field and electric field gradient at an atom in a weakly bound trimer. J Chem Phys 139(3):034320/1-034320/8 [http://dx.doi.org/10.1063/1.4811198]

239 CAS RN: 12347-08-9 MGD RN: 210930 MW

Cyanophosphinylidene

P

Bonds P–C C≡N

CNP C∞ v

C

N

r0 [Å] a 1.732(2) 1.167(2)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of cyanophosphinylidene (3Σ- electronic ground state) were recorded in the frequency region between 19 and 415 GHz using a combination of millimeter/submillimeter-wave direct absorption and FTMW spectroscopy. The radicals were produced in the free absorption cell by a reaction of phosphorus vapor with cyanogen, whereas the radicals were created in the Fourier transform spectrometer cavity from phosphorous trichloride. The r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 13 C). Halfen DT, Sun M, Clouthier DJ, Ziurys LM (2012) The microwave and millimeter rotational spectra of the PCN radical (X3Σ-). J Chem Phys 136(14):144312/1-144312/12 [http://dx.doi.org/10.1063/1.3696893]

240 CAS RN: 647838-64-0 MGD RN: 209758 MW

Cyano-κC-platinum Platinum monocyanide CNPt Pt C N C∞ v

192

Bonds Pt–C C≡N

3 Molecules Containing One Carbon Atom

r0 [Å] a 1.90114(22) 1.16073(33)

rs [Å] a 1.900385(65) 1.160956(28)

[Å] a r (1) m 1.900037(45) 1.160722(27)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of platinum monocyanide were recorded by source-modulated millimeter and submillimeter-wave spectrometers in the spectral ranges between 150 and 310 GHz and 340 and 580 GHz. The transient paramagnetic species was produced in a free space cell by a DC glow discharge through acetonitrile and Pt atoms, which were sputtered from a thin platinum sheet. Observed fine- and hyperfine spectral patterns indicated that the molecule is linear and has the 2∆5/2 ground electronic state. The r0 and r (1) structures were determined from the ground-state rotational constants of seven isotopic species m 194 196 (main, Pt, Pt, 194Pt/13C, 194Pt/15N, 196Pt/13C and 196Pt/15N). Okabayashi EY, Okabayashi T, Furuya T, Tanimoto M (2010) Millimeter- and submillimeter-wave spectroscopy of platinum monocyanide, PtCN. Chem Phys Lett 492(1-3):25-29

241 CAS RN: 192268-41-0 MGD RN: 116136 MW supported by ab initio calculations

Distance Rcm b

Carbon dioxide - dinitrogen (1/1) CN2O2 C2v O

C

O

N

N

r0 [Å] a 3.727(3)

Reproduced with permission of AIP Publishing [a].

a b

Parenthesized uncertainty in units of the last significant digit. Distance between the centers of mass of the monomer subunits.

The rotational spectra of the binary complex of carbon dioxide with dinitrogen were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 7.6 and 18.9 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main and two 15N) assuming a planar equilibrium configuration and unchanged geometries of the monomer subunits upon complexation. A large-amplitude bending motion of the N2 subunit of about 19.5° was derived from the values of the nearly identical nuclear quadrupole coupling constants of the N nuclei (in the main isotopic species). a. Frohman DJ, Contreras ES, Firestone RS, Novick SE, Klemperer W (2010) Microwave spectra, structure, and dynamics of the weakly bound complex, N2 CO2. J Chem Phys 133(24):244303/1-244303/6 doi:10.1063/1.3517061 IR

Distance Rcm b

C2v

r0 [Å] a 3.7285(5)

3 Molecules Containing One Carbon Atom

Angle

α

c

193

θ0 [deg] a 6.85(3)

Copyright 2011 with permission from Elsevier [b]. a

Parenthesized uncertainty in units of the last significant digit. Distance between C and the center-of-mass of the N2 subunit. c Angular oscillation of N2 subunit from exact T-shaped configuration. b

The rotationally resolved IR spectrum of the binary van der Waals complex was recorded for an 18O-enriched sample in a supersonic jet by a tunable diode laser spectrometer in the ν3 fundamental region at 2314 cm-1. The r0 structure was determined from the ground-state rotational constants of the 18OC18O ‧N2 isotopologue under the assumption that the structural parameters of the monomers were not changed upon complexation. The structure agrees well with the previously determined r0 structure which D. J. Frohman et al. obtained from the MW spectrum in 2010. b. Konno T, Yamaguchi S, Ozaki Y (2011) Infrared diode laser spectroscopy of N2-12C18O2. J Mol Spectrosc 270(1):66-69

242 CAS RN: 184590-84-9 MGD RN: 147358 IR

Carbon monoxide – dinitrogen monoxide (1/1) Carbon monoxide – nitrous oxide (1/1) CN2O2 Cs C

Distance Rcm b

r0 [Å] 3.509

N

O

N

O

a

Reproduced with permission from the PCCP Owner Societies.

a b

Uncertainty was not given in the original paper. Distance between centers of mass of both monomer subunits.

The rotationally resolved IR spectrum of the binary complex of carbon monoxide with nitrous oxide was investigated in a supersonic jet by quantum cascade laser spectroscopy in the CO stretching region at about 2150 cm-1. A new O-bonded isomer was observed. The partial r0 structure was determined under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Barclay AJ, Lauzin C, Sheybani-Deloui S, Michaelian KH, Moazzen-Ahmadi N (2017) Detection of a higher energy isomer of the CO-N2O van der Waals complex and determination of two of its intermolecular frequencies. Phys Chem Chem Phys 19(2):1610-1613

243 CAS RN: 437702-53-9 MGD RN: 145341 IR

Carbonyl sulfide – dinitrogen monoxide (1/1) CN2O2S Cs O

Distance

r0 [Å] a

C

S

N

N

O

194

3 Molecules Containing One Carbon Atom

Rcm b

3.8674(9)

Angles

θ0 [deg] a

c

ϕ1 ϕ2 d

116.8(37) 133.2(18)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Angle between Rcm and the NNO axis. d Angle between Rcm and the OCS axis. b

The rotationally resolved IR spectrum of the binary complex was recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the region of the OCS ν1 fundamental band at 2065 cm-1. Three bands were analyzed; one of them was assigned to the previously detected planar conformer, whereas two other bands were assigned to the second planar conformer with a slipped near-parallel structure. The partial r0 structure of the newly detected conformer was determined from the ground-state rotational constants of two isotopic species (main and 15N2) under the assumption that the geometries of the monomer subunits were not changed upon complexation. Afshari M, Dehghany M, Norooz Oliaee J, Moazzen-Ahmadi N (2010) Infrared spectra of the OCS-N2O complex and observation of a new isomer. Chem Phys Lett 489(1-3):30-34.

244 CAS RN: 198630-14-7 MGD RN: 408446 MW augmented by ab initio calculations Bonds N(1)≡C C–N(2) N(2)–Si

(Cyanoimino)silylene CN2Si C∞ v N

C

N

Si

r see [Å] a 1.1656(1) 1.3037(2) 1.5640(2)

Reproduced with permission from The Royal Society of Chemistry. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were investigated in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 42 GHz. The transient species were produced by a pulsed discharge of methyl cyanide with silane. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants of seven isotopic species (main, 13C, two 13C/15N, 15N2, 29Si/15N2 and 30Si/15N2) taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(T+d)Z harmonic and anharmonic (cubic) force constants. Thorwirth S, Kaiser RI, Crabtree KN, McCarthy MC (2015) Spectroscopic and structural characterization of three silaisocyanides: exploring an elusive class of reactive molecules at high resolution. Chem Comm 51(56):11305-11308

3 Molecules Containing One Carbon Atom

245 CAS RN: 509-14-8 MGD RN: 121400 GED augmented by QC computations

195

Tetranitromethane CN4O8 S4

Bonds C–N N=O (eclipsed) b N=O (staggered) c

re [Å] a 1.509(5) 1.201(3) 1.199(3)

Bond angles N–C–N(+) d N–C–N(−) d C–N=O (eclipsed) b C–N=O (staggered) c O=N=O

θe [deg] a

Torsion angle N–C–N=O (eclipsed) b

τe [deg] a

NO2

NO2

O 2N O 2N

105.1(16) 111.7(8) 113.5(8) 117.2(8) 129.2(17)

5.4(25)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors corresponding to 99.7 % probability. b N=O bond is nearly eclipsing one of the C–N bonds. c N=O bond in the staggered position with respect to the other C–N bonds. d N–C–N(+) and N–C–N(–) angles include the N atoms of the positive and negative N–C– N=O(eclipsed) torsional angles, respectively. The GED experiment was carried out at Tnozzle =282 K. For the first time in the GED analysis, the four-dimensional dynamic model was applied for description of the correlated torsional dynamics. The molecule with large-amplitude motions of four C−NO2 groups and lowest vibrational frequencies of 57 (E), 64 (A) and 84 (B) cm-1 (MP2/cc-pVTZ) was presented as an example of the molecular system of extreme flexibility. The model was described by optimized number of pseudo-conformers (82) weighted according to energy of the PES points from PBE0/SVP computations. Relaxation effects in the structural parameters of pseudo-conformers were fixed at the computed values. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the PBE0/SVP quadratic and cubic force constants taking into account non-linear kinematic effects. Vishnevskiy YV, Tikhonov DS, Schwabedissen J, Stammler HG, Moll R, Krumm B, Klapötke TM, Mitzel NW (2017) Tetranitromethane: A nightmare of molecular flexibility in the gaseous and solid states. Angew Chem Int Ed / Angew Chem 56/129 (32/32):9619-9623/9748-9752

246 CAS RN: MGD RN: 130653 IR

Carbon disulfide – neon (1/1) CNeS2 C2v S

Distance C…Ne

r0 [Å] a 3.578

C

S

Ne

196

Angle

ϕ

b

3 Molecules Containing One Carbon Atom

θ0 [deg] a 86.9

Copyright 2012 with permission from Elsevier.

a b

Uncertainty was not given in the original paper. Effective angle between the S=C=S axis and Rcm.

The rotationally resolved mid-IR spectrum of the binary van der Waals complex was recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the region of the CS2 ν3 fundamental band at 1535 cm-1. The complex was found to have a T-shaped structure. The equilibrium structure is suggested to be of C2v symmetry. The r0 structure was determined under the assumption that the structural parameters of the carbon disulfide subunit were not changed upon complexation. Mivehvar F, Lauzin C, McKellar ARW, Moazzen-Ahmadi N (2012) Infrared spectra of rare gas-carbon disulfide complexes: He-CS2, Ne-CS2, and Ar-CS2. J Mol Spectrosc 281:24-27

247 CAS RN: 33637-76-2 MGD RN: 149980 MW

Nickel monocarbonyl CNiO (see comment) Ni

Bonds Ni–C C≡O

re [Å] a 1.6715(19) 1.1596(25)

Angle 〈α2〉1/2 b

θ [deg]

C

O

8.32

Reprinted with permission. Copyright 2011 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Root-mean-square bending displacement, α = [180° ‒ ∠( Ni–C≡O)].

The rotational spectrum of nickel monocarbonyl (1Σ+ electronic ground state) was investigated in the ground and ν2 excited vibrational states by source-modulated MW spectroscopy in the millimeter-wave and submillimeterwave ranges. The transient species was created in the free space cell by a DC glow discharge of CO and Ni vapor. Only the main isotopic species was observed. The molecule was found to behave as a quasi-linear molecule with a large-amplitude bending vibration; the structure was determined using a rigid-bender model. Okabayashi T, Yamamoto T, Okabayashi EY, Tanimoto M (2011) Low-energy vibrations of the group 10 metal monocarbonyl MCO (M = Ni, Pd, and Pt): Rotational spectroscopy and force field analysis. J Phys Chem A 115(10):1869-1877

248 CAS RN: 41772-86-5

Palladium monocarbonyl

3 Molecules Containing One Carbon Atom

MGD RN: 145261 MW

197

COPd (see comment) Pd

Bonds Pd–C C≡O

re [Å] a 1.8439(10) 1.1484(15)

Angle 〈α2〉1/2 b

θe [deg] a

C

O

9.35

Reprinted with permission. Copyright 2011 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Root-mean-square bending displacement, α = [180° ‒ ∠(Pd–C≡O)].

The rotational spectrum of palladium monocarbonyl (1Σ+ electronic ground state) in the ground and ν2 excited vibrational states was recorded by source-modulated MW spectroscopy in the millimeter-wave and submillimeter-wave range. The transient species was created in the free space cell by a DC glow discharge of CO and Pd vapor. Five different Pd isotopic species were studied in natural abundance. The molecule was found to behave as a quasi-linear molecule with a large-amplitude bending vibration; the structure was determined using a rigid-bender model. Okabayashi T, Yamamoto T, Okabayashi EY, Tanimoto M (2011) Low-energy vibrations of the group 10 metal monocarbonyl MCO (M = Ni, Pd, and Pt): Rotational spectroscopy and force field analysis. J Phys Chem A 115(10):1869-1877

249 CAS RN: 49819-49-0 MGD RN: 145992 MW

Platinum monocarbonyl COPt (see comment) Pt

Bonds Pt–C C≡O

re [Å] a 1.7615(15) 1.1545(21)

Angle 〈α2〉1/2 b

θ [deg]

C

O

7.64

Reprinted with permission. Copyright 2011 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Root-mean-square bending displacement, α = [180° ‒ ∠(Pt–C≡O)].

The molecular structure of platinum monocarbonyl was reinvestigated using previously published experimental rotational constants. The molecule was found to behave as a quasi-linear molecule with a large-amplitude bending vibration; the equilibrium structure was determined applying a rigid-bender model. Okabayashi T, Yamamoto T, Okabayashi EY, Tanimoto M (2011) Low-energy vibrations of the group 10 metal monocarbonyl MCO (M = Ni, Pd, and Pt): Rotational spectroscopy and force field analysis. J Phys Chem A 115(10):1869-1877

198

3 Molecules Containing One Carbon Atom

250 CAS RN: MGD RN: 131361 MW supported by ab intio calculations

Carbon monoxide – sulfur dioxide (1/1) CO3S Cs (effective symmerty) a

Distances Rcm b S…C

r0 [Å] 4.0586(11) 3.487(20)

Angles

θ0 [deg] a

c

ϕ φd

S…C≡O

O

S

O

C

O

80.9(32) 180(3) 174.1(8)

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Angle between Rcm and the C2 axis of the SO2 subunit. d Angle between Rcm and the CO axis. b

The rotational spectrum of the binary complex of sulfur dioxide with carbon monoxide was recorded by a pulsed-beam FTMW spectrometer in the frequency region between 7 and 16 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 13 C, two 18O and 34S) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Lovas FJ, Sprague MK (2015) Microwave rotational spectral study of SO2-CO. J Mol Spectrosc 316:49-53

251 CAS RN: 75-15-0 MGD RN: 477869 UED

Distances C–S S…S

Carbon disulfide CS2 D∞h S=C=S

r [Å] a,b 1.553 3.105

Reproduced with permission of SNCSC.

a b

Uncertainties were not stated. Structure type was not specified.

The UED experiment was carried for aligned molecules in the ground electronic state.

3 Molecules Containing One Carbon Atom

199

Yang J, Beck J, Uiterwaal CJ, Centurion M (2015) Imaging of alignment and structural changes of carbon disulfide molecules using ultrafast electron diffraction. Nat Commun 6:9172/9171-9172/9179

252 CAS RN: 127538-14-1 MGD RN: 134049 MW augmented by ab initio calculations

Methanetetraylbisilylene Disilicon carbide CSi2 C2v C Si

Bond C=Si Bond angle Si=C=Si

a

r0 [Å] 1.693(1)

θ0 [deg] a 115.8(2)

Si

a

r [Å] 1.69272(2) se e

θ see [deg] a

114.871(3)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit is 1σ value.

The rotational spectrum of the title compound was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 43 GHz. The transient species was produced by a low-current discharge of a mixture of silane with hydrocarbon. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 13C, 29 Si and 30Si). The semiexperimental equilibrium structure r see was obtained taking into account rovibrational corrections calculated with the CCSD(T)/cc-pVQZ harmonic and anharmonic (cubic) force constants. McCarthy MC, Baraban JH, Changala PB, Stanton JF, Martin-Drumel MA, Thorwirth S, Gottlieb CA, Reilly NJ (2015) Discovery of a missing link: detection and structure of the elusive disilicon carbide cluster. J Phys Chem Lett 6(11):2107-2111

200

3 Molecules Containing One Carbon Atom

References: 155. Stephens SL, Mizukami W, Tew DP, Walker NR, Legon AC (2012) Molecular geometry of OC⋅⋅⋅AgI determined by broadband rotational spectroscopy and ab initio calculations. J Chem Phys 136(6):064306/1-064306/9 156. Okabayashi T, Okabayashi EY, Koto F, Ishida T, Tanimoto M (2009) Detection of free monomeric silver(I) and gold(I) cyanides, AgCN and AuCN: Microwave spectra and molecular structure. J Amer Chem Soc 131(33):11712-11718 157. Mück LA, Thorwirth S, Gauss J (2015) The semiexperimental equilibrium structures of AlCCH and AlNC. J Mol Spectrosc 311:49-53 158. Evangelisti L, Gou Q, Feng G, Caminati W (2016) The rotational spectrum of CF3Cl-Ar. Chem Phys Lett 653(3):1-4 159. Mivehvar F, Lauzin C, McKellar ARW, Moazzen-Ahmadi N (2012) Infrared spectra of rare gas-carbon disulfide complexes: He-CS2, Ne-CS2, and Ar-CS2. J Mol Spectrosc 281:24-27 160. See 156. 161. Feng G, Gou Q, Evangelisti L, Grabow JU, Caminati W (2017) Pulsed jet Fourier transform microwave spectroscopy of the BF3-CO complex. J Mol Spectrosc 335(5):80-83 162. Rivera-Rivera LA, Scott KW, McElmurry BA, Lucchese RR, Bevan JW (2013) Compound modelmorphed potentials contrasting OC-79Br35Cl with the halogen bonded OC-35Cl2 and hydrogen-bonded OC-HX (X=19F, 35Cl, 79Br). Chem Phys 425:162-169 163. Durig JR, Zhou SX, Garner AX, Durig NE (2009) Structural parameters, centrifugal distortion constants, and vibrational spectra of F2C=NX (X = H, F, Cl, Br) molecules. J Mol Struct 922(1-3):11-18 164. Durig JR, Zhou X, Durig NE, Nguyen D, Durig DT (2009) Vibrational spectra and structural parameters of some XNCO and XOCN (X = H, F, Cl, Br) molecules. J Mol Struct 917(1):37-51 165. (a) Klapötke TM, Krumm B, Moll R, Rest SF, Vishnevskiy YV, Reuter C, Stammler HG, Mitzel NW (2014) Halogenotrinitromethanes: A combined study in the crystalline and gaseous phase and using quantum chemical methods. Chem Eur J 20 (40):12962-12973 (b) Sadova NI, Popik NI, Vilkov LV (1976) Electron-diffraction investigation of the structure of the HC(NO2)3, ClC(NO2)3, and BrC(NO2)3 molecules in the gas phase. J Struct Chem/Zh Strukt Khim. 17/17 (2/2):257-262/298-303 166. See 163. 167. See 164. 168. Vogt N, Demaison J, Rudolph HD (2014) Accurate equilibrium structures of fluoro- and chloroderivatives of methane. Mol Phys 112(22):2873-2883 169. Li DQ, Schwabedissen J, Stammler HG, Mitzel NW, Willner H, Zeng XQ (2016) Dichlorophosphanyl isocyanate - spectroscopy, conformation and molecular structure in the gas phase and the solid state. Phys Chem Chem Phys 18 (37):26245-26253 170. Demaison J, Császár AG (2012) Equilibrium CO bond lengths. J Mol Struct 1023:7-14 171. (a) Zakharov AV, Zhabanov YA (2010) An improved data reduction procedure for processing electron diffraction images and its application to structural study of carbon tetrachloride. J Mol Struct 978 (13):61-66 (b) Vogt N, Rudert R, Rykov AN, Karasev NM, Shishkov IF, Vogt J (2011) Use of imaging plates (IPs) in the gas-phase electron diffraction (GED) experiments on the EG-100 M apparatus. The tetrachloromethane molecule as a test object. Struct Chem 22 (2):287-291 (c) Morino Y, Nakamura Y, Iijima T (1960) Mean square amplitudes and force constants of tetrahedral molecules. I. Carbon tetrachloride and germanium tetrachloride. J Chem Phys 32(3):643-652 172. Ezhov YS, Komarov SA, Simonenko EP, Pavelko RG, Sevast'yanov VG, Kuznetsov NT (2009) Molecular structure of C(SiCl3)4 tetrakis(trichlorosilyl)methane. J Struct Chem (Engl Transl)/Zh Strukt Khim 50/50 (1/1):153-157/160-164 173. See 165(a). 174. Koucký J, Kania P, Uhlíková T, Kolesniková L, Beckers H, Willner H, Urban S (2013) Geometry and microwave rotational spectrum of the FC16O18O. radical. J Phys Chem A 117(39):10138-10143 175. See 170. 176. Stephens SL, Walker NR, Legon AC (2011) Rotational spectra and properties of complexes B⋅⋅⋅ICF3 (B = Kr or CO) and a comparison of the efficacy of ICl and ICF3 as iodine donors in halogen bond formation. J Chem Phys 135(22):224309/1-224309/8 177. Anable JP, Hird DE, Stephens SL, Zaleski DP, Walker NR, Legon AC (2015) Characterization of the weak halogen bond in N2⋅⋅⋅ICF3 by pure rotational spectroscopy. Chem Phys Lett 625:179-185 178. See 163.

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(b) Schreiner PR, Reisenauer HP (2008) Spectroscopic identification of dihydroxycarbene. Angew. Chem 120(37):7179-7182; Angew Chem Int Ed 47(37):7071-7074 208. Zhu Y, Zheng R, Li S, Yang Y, Duan C (2013) Infrared spectra and tunneling dynamics of the N2-D2O and OC-D2O complexes in the ν2 bend region of D2O. J Chem Phys 139(21):214309/1-214309/6 209. Mori T, Suma K, Sumiyoshi Y, Endo Y (2011) Spectroscopic detection of the most stable carbonic acid, cis-cis H2CO3. J Chem Phys 134(4):044319/1-044319/6 210. Mackenzie RB, Dewberry CT, Leopold KR (2015) Gas phase observation and microwave spectroscopic characterization of formic sulfuric anhydride. Science 349(6243):58-61 211. (a) Belyakov AV, Khramov AN, Naumov VN (2010) Molecular structure and conformational preferences of gaseous methylthiodibromophosphite, Br2PSCH3, studied by gas electron diffraction and quantum-chemical calculations. Russ J Gen Chem / Zh Obshch Khim 80/ 0 (11/11):2249-2258/17851794 (b) Naumov VA, Kataeva OV, Sinyashin OG (1984) Molecular structure of methyl thiodichloroophosphite and methyl thiodibromophosphite. J Struct Chem (Engl Transl) /Zh Strukt Khim 25/25 (3/3):411-415/79-84 212. Bills BJ, Elmuti LF, Sanders AJ, Steber AL, Peebles RA, Peebles SA, Groner P, Neill JL, Muckle MT, Pate BH (2011) C-H⋅⋅⋅O interaction and water tunneling in the CHClF2-H2O dimer. J Mol Spectrosc 268(1-2):7-15 213. Seifert NA, Guirgis GA, Pate BH (2012) The molecular structure of methyl(difluoro)silyl chloride as determined by broadband microwave spectroscopy. J Mol Struct 1023:222-226 214. Feng G, Evangelisti L, Gasparini N, Caminati W (2012) On the Cl···N halogen Bond: A rotational study of CF3Cl···NH3 Chem Eur J 18:1364-1368 215. Min J, Bucchino MP, Kilchenstein KM, Ziurys LM (2016) Rotational spectroscopy of ClZnCH3 (X1A1): Gas-phase synthesis and characterization of a monomeric Grignard-type reagent. Chem Phys Lett 646(4):174-178 216. Belyakov AV, Khramov AN, Naumov VA (2010) Molecular structure and conformational preferences of methylthiodichlorophosphite, Cl2PSCH3, as studied by gas electron diffraction and quantumchemical calculations. J Mol Struct 978 (1-3):4-10 217. Stephens SL, Walker NR, Legon AC (2011) Internal rotation and halogen bonds in CF3I⋅⋅⋅NH3 and CF3I⋅⋅⋅N(CH3)3 probed by broadband rotational spectroscopy. Phys Chem Chem Phys 13(46):2073620744 218. Bucchino MP, Young JP, Sheridan PM, Ziurys LM (2014) Structural determination and gas-phase synthesis of monomeric, unsolvated IZnCH3 (X1A1): a model organozinc halide. J Phys Chem A 118(47):11204-11210 219. Ishiguro M, Harada K, Tanaka K, Tanaka T, Sumiyoshi Y, Endo Y (2012) Fourier-transform microwave spectroscopy of the H2-HCN complex. Chem Phys Lett 554:33-36 220.(a)Blanco S, Pinacho P, López JC (2016) Hydrogen-bond cooperativity in formamide2-water: A model for water-mediated interactions. Angew Chem 128(32):9477-9481; Angew Chem Int Ed 55(32):93319335 (b) Alessandrini S, Puzzarini C. (2016) Structural and energetic characterization of prebiotic molecules: The case study of formamide and its dimer. J Phys Chem A 120(27):5257-5263 221. Liu X, Xu Y (2011) Infrared and microwave spectra of the acetylene-ammonia and carbonyl sulfideammonia complexes: a comparative study of a weak C-H⋅⋅⋅N hydrogen bond and an S⋅⋅⋅N bond. Phys Chem Chem Phys 13(31):14235-14242 222. Mackenzie RB, Dewberry CT, Leopold KR (2014) The formic acid-nitric acid complex: microwave spectrum, structure, and proton transfer. J Phys Chem A 118(36):7975-7985 223. Liu J, Chen MW, Melnik D, Miller TA, Endo Y, Hirota E (2009) The spectroscopic characterization of the methoxy radical. II. Rotationally resolved A2A1-X2E electronic and X2E microwave spectra of the perdeuteromethoxy radical CD3O. J Chem Phys 130(7):074303/1-074303/11 224. Oyama T, Nakajima M, Sumiyoshi Y, Endo Y (2013) Pure rotational spectroscopy of the H2O-transHOCO complex. J Chem Phys 138(20):204318/1-204318/8 225. Guirgis GA, Sawant DK, Brenner RE, Deodhar BS, Seifert NA, Geboes Y, Pate BH, Herrebout WA, Hickman DV, Durig JR (2015) Microwave, r0 structural parameters, conformational stability, and vibrational assignment of (chloromethyl)fluorosilane. J Phys Chem A 119(47):11532-11547 226. (a) Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48(17):8603-8612 (b) Brain PT, Rankin DWH, Robertson HE, Downs AJ, Greene TM, Hoffman M, Schleyer PvR (1995) Molecular structure of 1-(dichloroboryl)pentaborane(9), in the gas phase as determined by electron diffraction and supported by theoretical calculations. J Mol Struct 352:135-144 227. Puzzarini C (2012) Molecular structure of thiourea. J Phys Chem A 116(17):4381-4387

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228. Nakajima M, Endo Y (2014) Spectroscopic characterization of the complex between water and the simplest Criegee intermediate CH2OO. J Chem Phys 140(13):134302/1-134302/5 229. Flory MA, Apponi AJ, Zack LN, Ziurys LM (2010) Activation of methane by zinc: Gas-phase synthesis, structure, and bonding of HZnCH3. J Amer Chem Soc 132(48):17186-17192 230. Durig JR, Panikar SS, Groner P, Nanaie H, Bürger H, Moritz P (2010) Microwave spectrum, r0 structure, dipole moment, barrier to internal rotation, and ab initio calculations for fluoromethylsilane. J Phys Chem A 114(12):4131-4137 231. Gou Q, Spada L, Lòpez JC, Grabow JU, Caminati W (2015) Chloromethane-water adduct: rotational spectrum, weak hydrogen bonds, and internal dynamics. Chem Asian J 10(5):1198-1203 232. See 230. 233. See 230. 234. Aldridge S, Downs AJ, Tang CY, Parsons S, Clarke MC, Johnstone RDL, Robertson HE, Rankin DWH, Wann DA (2009) Structures and aggregation of the methylamine-borane molecules, MenH3nN·BH3 (n=1-3), studied by X-ray diffraction, gas-phase electron diffraction, and quantum chemical calculations. J Am Chem Soc 131 (6):2231-2243 235. See 234. 236. Blanco S, Pinacho P, López J. C (2017) Structure and dynamics in formamide-(H2O)3: A water pentamer analogue. J Phys Chem Lett 8(24):6060-6066 237. See 159. 238. Mackenzie RB, Timp BA, Mo Y, Leopold KR (2013) Effects of a remote binding partner on the electric field and electric field gradient at an atom in a weakly bound trimer. J Chem Phys 139(3):034320/1034320/8 239. Halfen DT, Sun M, Clouthier DJ, Ziurys LM (2012) The microwave and millimeter rotational spectra of the PCN radical (X3Σ-). J Chem Phys 136(14):144312/1-144312/12 240. Okabayashi EY, Okabayashi T, Furuya T, Tanimoto M (2010) Millimeter- and submillimeter-wave spectroscopy of platinum monocyanide, PtCN. Chem Phys Lett 492(1-3):25-29 241. (a)Frohman DJ, Contreras ES, Firestone RS, Novick SE, Klemperer W (2010) Microwave spectra, structure, and dynamics of the weakly bound complex, N2 CO2. J Chem Phys 133(24):244303/1244303/6 (b)Konno T, Yamaguchi S, Ozaki Y (2011) Infrared diode laser spectroscopy of N2-12C18O2. J Mol Spectrosc 270(1):66-69 242. Barclay AJ, Lauzin C, Sheybani-Deloui S, Michaelian KH, Moazzen-Ahmadi N (2017) Detection of a higher energy isomer of the CO-N2O van der Waals complex and determination of two of its intermolecular frequencies. Phys Chem Chem Phys 19(2):1610-1613 243. Afshari M, Dehghany M, Norooz Oliaee J, Moazzen-Ahmadi N (2010) Infrared spectra of the OCSN2O complex and observation of a new isomer. Chem Phys Lett 489(1-3):30-34. 244. Thorwirth S, Kaiser RI, Crabtree KN, McCarthy MC (2015) Spectroscopic and structural characterization of three silaisocyanides: exploring an elusive class of reactive molecules at high resolution. Chem Comm 51(56):11305-11308 245. Vishnevskiy YV, Tikhonov DS, Schwabedissen J, Stammler HG, Moll R, Krumm B, Klapötke TM, Mitzel NW (2017) Tetranitromethane: A nightmare of molecular flexibility in the gaseous and solid states. Angew Chem Int Ed / Angew Chem 56/129 (32/32):9619-9623/9748-9752 246. See 159. 247. Okabayashi T, Yamamoto T, Okabayashi EY, Tanimoto M (2011) Low-energy vibrations of the group 10 metal monocarbonyl MCO (M = Ni, Pd, and Pt): Rotational spectroscopy and force field analysis. J Phys Chem A 115(10):1869-1877 248. See 247. 249. See 247. 250. Lovas FJ, Sprague MK (2015) Microwave rotational spectral study of SO2-CO. J Mol Spectrosc 316:49-53 251. Yang J, Beck J, Uiterwaal CJ, Centurion M (2015) Imaging of alignment and structural changes of carbon disulfide molecules using ultrafast electron diffraction. Nat Commun 6:9172/1-9172/10. 252. McCarthy MC, Baraban JH, Changala PB, Stanton JF, Martin-Drumel MA, Thorwirth S, Gottlieb CA, Reilly NJ (2015) Discovery of a missing link: detection and structure of the elusive disilicon carbide cluster. J Phys Chem Lett 6(11):2107-2111

Chapter 4. Molecules with Two Carbon Atoms 253 CAS RN: 1669444-88-5 MGD RN: 454543 MW augmented by ab initio calculations Bonds Ag–C C≡C C–Cl Ag...Cl

r0 [Å] a 2.015(14) 1.2219 b 1.635(6) 4.8722(2)

(2-Chloroethynyl)silver C2AgCl C∞v Cl

C

Ag

C

rs [Å] a

4.8729(12)

Reprinted with permission. Copyright 2015 American Chemical Society.

a b

Parenthesized estimated uncertainties in units of the last significant digit. Assumed at the CCSD(T)/aug-cc-pV5Z value.

The rotational spectra of (2-chloroethynyl)silver were recorded in a pulsed supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The transient species was produced by the reaction of tetrachloromethane with laser-ablated silver. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 37 Cl, 13C2, 109Ag, 109Ag/37Cl and 109Ag/13C2). Zaleski DP, Tew DP, Walker NR, Legon AC (2015) Chemistry in laser-induced plasmas: formation of M-C≡CCl (M = Ag or Cu) and their characterization by rotational spectroscopy. J Phys Chem A 119(12):2919-2925 254 CAS RN: 251943-87-0 MGD RN: 215095 UV supported by QC calculations

Aluminum acetylide Aluminum dicarbide C2Al C2v C Al

a

Bonds C≡C Al–C

r0 [Å] 1.271(2) 1.926(1)

Bond angle C–Al–C

θ0 [deg] a

C

38.5(2)

Reproduced with permission of AIP Publishing. a

Parenthesized uncertainties in units of the last significant digit.

The rotationally resolved laser-induced fluorescence spectrum of aluminum acetylide (2A1 electronic ground state) was recorded in a supersonic jet in the region between 22080 and 22120 cm-1. The radicals were produced by electron bombardment of trimethylaluminum. The r0 structure was determined from the ground-state rotational constants of the main isotopic species. In contrast to SiC2, the title molecule (in the electronic ground state) shows no spectroscopic evidence of facile isomerization to the linear structure.

© Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_4

205

206

4 Molecules with Two Carbon Atoms

Yang J, Judge RH, Clouthier DJ (2011) Pulsed discharge jet electronic spectroscopy of the aluminum dicarbide (AlC2) free radical. J Chem Phys 135(12):124302/1-124302/7 doi:10.1063/1.3638049

255 CAS RN: 195068-32-7 MGD RN: 209525 MW

Arsinidyneethenylidene Arsenic dicarbide C2As C∞ v C

Bonds C=As C=C

r0 [Å] a 1.7362(33) 1.2884(48)

rs [Å] a 1.7427(5) 1.2851(4)

As

C

r m [Å] a 1.7455(3) 1.2872(4) (1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of the title compound (2Π1/2 electronic ground state) were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 12 and 40 GHz. The radical was produced by a DC discharge of arsenic trichloride with acetylene or methane. (1) The r0, rs and the mass-dependent r m structures were determined from the ground-state rotational constants of four isotopic species (main, two 13C and 13C2). The determined bond lengths indicated the predominant double bond character. Sun M, Clouthier DJ, Ziurys LM (2009) The Fourier transform microwave spectrum of the arsenic dicarbide radical (CCAs: X2Π1/2) and its 13C isotopologues. J Chem Phys 131(22):224317/1-224317/10 doi:10.1063/1.3267483

256 CAS RN: 131297-31-9 MGD RN: 125723 MW augmented by QC calculations

(Z)-N-Bromocarbonocyanidimidic fluoride (Z)-N-Bromocyanofluoromethanimine C2BrFN2 Cs Br

N

a

Bonds N(1)–Br C(1)=N(1) C(1)–F C(1)–C(2) C(2)≡N(2)

r0 [Å] 1.865(5) 1.270(5) 1.327(3) 1.437(3) 1.160(3)

Bond angles Br–N(1)=C(1) N(1)=C(1)–F N(1)=C(1)–C(2) C(1)–C(2)≡N(2)

θ0 [deg] a 114.4(5) 127.4(5) 119.7(5) 180

Copyright 2009 with permission from Elsevier.

F

C N

4 Molecules with Two Carbon Atoms a

207

Parenthesized estimated uncertainties in units of the last digit.

The r0 structure was determined by adjusting the MP2/6-311+G(d) structure to the previously published groundstate rotational constants of the 79Br and 81Br isotopic species. Durig JR, Zhou SX, Zhou CX, Durig NE (2010) Structural parameters, vibrational spectra and centrifugal distortion constants of F(CN)C=NX (X = H, F, Cl, Br) and CH3(Y)C=NH (Y = H, CN). J Mol Struct 967(1-3):114

257 CAS RN: 7601-99-2 MGD RN: 214375 MW supported by ab initio calculations

Bonds C–Br C–C

rs [Å] a 1.902(3) 1.495(7)

Bond angle Br–C–C

θs [deg] a

2-Bromo-2,2-difluoroacetonitrile

F

C2BrF2N Cs F

C

Br

N

110.5(3)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7.7 and 18 GHz. The partial rs structure was determined from the ground-state rotational constants of six isotopic species (main, 81 Br, two 13C and two 13C/81Br). Grubbs GS, Bailey WC, Cooke SA (2011) Concerning the electronic and geometric structure of bromodifluoroacetonitrile, CBrF2CN. J Mol Struct 987(1-3):255-261

258 CAS RN: 1670231-90-9 MGD RN: 454371 MW augmented by ab initio calculations

Bonds Cu–C C≡C C–Cl Cu...Cl

r0 [Å] a 1.812(16) 1.2233 b 1.639(6) 4.6736(2)

(2-Chloroethynyl)copper C2ClCu C∞ v Cl

rs [Å] a

4.6743(10)

Reprinted with permission. Copyright 2015 American Chemical Society.

C

C

Cu

208 a b

4 Molecules with Two Carbon Atoms

Parenthesized estimated uncertainties in units of the last significant digit. Assumed at the CCSD(T)/aug-cc-pV5Z value.

The rotational spectra of (2-chloroethynyl)copper were recorded in a pulsed supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The transient species was produced by the reaction of tetrachloromethane with laser-ablated copper. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 37 Cl, 13C2 and 65Cu). Zaleski DP, Tew DP, Walker NR, Legon AC (2015) Chemistry in laser-induced plasmas: formation of M-C≡CCl (M = Ag or Cu) and their characterization by rotational spectroscopy. J Phys Chem A 119(12):2919-2925

259 CAS RN: 431-10-7 MGD RN: 387587 GED augmented by DFT computations

Bonds C=O(1) C=O(2) C–F C–C C–Cl Bond angles C–C–Cl C–C=O(1) O=C–Cl C–C=O(2) C–C–F O=C–F Dihedral angles Cl–C–C–F O=C–C–F O=C–C–Cl O=C–C=O

2-Chloro-2-oxo-acetyl fluoride Oxalyl chloride fluoride C2ClFO2 Cs (anti) C1 (gauche)

anti 1.188(2) 1.185(2) 1.333(3) 1.546(4) 1.741(2)

anti 112.0(3) 123.0(4) 125.0(2) 126.9(5) 110.1(3) 123.1(3)

anti 180.0 0.0 0.0 180.0

rg [Å] a,b gauche 1.187(2) 1.185(2) 1.339(3) 1.529(4) 1.756(2)

O

Cl

F

O

anti

θα [deg] a,b

gauche 111.9(3) 123.2(4) 124.9(4) 124.9(5) 109.9(3) 125.1(3)

gauche

τα [deg] c

gauche 60.0 -122.8 -120.9 56.4

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 2σ values. Structural parameters of the less stable gauche conformer were tied to those of the anti conformer by parameter differences from B3LYP/cc-pVTZ computation. c Correspond to minima of PES. b

The GED experiments were carried out at different temperatures (Tnozzle of 295, 354, 431 and 583 K).

4 Molecules with Two Carbon Atoms

209

The molecular system was modelled as a mixture of two conformers, anti and gauche, with the antiperiplanar and synclinal Cl–C–C–F torsional angles, respectively, which were related by a PEF of the form: 2V = V1(1 + cosϕ) – V2(1 – 2cosϕ) + V3(1 + 3cosϕ). From the data recorded at the lowest temperature, the PEF constants were refined to be V1 =1.5(30), V2 =0.53(17) and V3 =0.40(31) (in kcal mol-1); the ratio of the conformers was determined to be anti : gauche = 80 : 20 (in %). Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using the B3LYP/cc-pVTZ harmonic force constants. Friesen DT, Johnson RJG, Hedberg L, Hedberg K (2011) Structure and torsional properties of oxalyl chloride fluoride in the gas phase: An electron-diffraction investigation. J Phys Chem A 115 (24):6702-6708

260 CAS RN: 78366-54-8 MGD RN: 514083 GED and augmented by QC computations

Bonds C(1)–Cl C(1)–N C=O C(2)=N C=S Bond angles Cl–C–N Cl–C=O N–C=O C–N=C N=C=S Dihedral angle O=C–N=C

Chloroisothiocyanatooxomethane Carbono(isocyanatidic) chloride C2ClNOS Cs (anti) Cs (syn)

re [Å] a,b syn 1.738(3) 1 1.370(4) 2 1.187(4) 3 1.212(4) 4 1.545(2) 5

anti 1.762(3) 1 1.366(4) 2 1.183(4) 3 1.213(4) 4 1.543(2) 5

rg [Å] a anti syn 1.769(3) 1.747(3) 1.375(4) 1.379(4) 1.187(4) 1.191(4) 1.217(4) 1.216(4) 1.549(2) 1.551(2)

θe [Å] a,b

anti 112.7(9) 6 122.3(10) 7 125.1(13) c 135.7(12) 8 177.2(24) 9

anti 180.0 d

syn 110.4(9) 6 123.2(10) 7 126.4(13) c 135.0(12) 8 176.7(24) 9

anti

τe [deg]

syn 0.0 d

Reprinted with permission. Copyright 2013 American Chemical Society.

syn

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from MP2_full/cc-pVTZ computation. c Dependent parameter. d Fixed. b

The GED experiment was carried out at Tnozzle = 274…277 K. The title compound was found to exist as a mixture of the anti and syn conformers with the antiperiplanar and synclinal O=C–N=C torsional angles, respectively, in the ratio anti : syn = 84(6) : 16(6) (in %). The low barrier to rotation around the N–C bond, estimated to be in the range between 0.6 and 1.5 kcal mol-1 (MP2 and B3LYP in conjunction with various basis sets), agrees well with the experimental value of 0.98(15) kcal mol-1 determined by vibrational matrix isolation (Ar) IR spectroscopy.

210

4 Molecules with Two Carbon Atoms

The intriguing major stability of the anti conformer was explained by a donation of the σ-type lone pair of electrons on the nitrogen atom into the antibonding orbital of the C–Cl bond. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from the MP2_full/cc-pVTZ quadratic and cubic force fields taking into account non-linear kinematic effects. Ramos LA, Ulic SE, Romano RM, Erben MF, Vishnevskiy YV, Reuter CG, Mitzel NW, Beckers H, Willner H, Zeng XQ, Bernhardt E, Ge MF, Tong SR, Della Védova CO (2013) Spectroscopic characterization and constitutional and rotational isomerism of ClC(O)SCN and ClC(O)NCS. J Phys Chem A 117 (11):2383-2399

261 CAS RN: 569-89-2 MGD RN: 541116 GED supplemented by QC computations

Thiocyanic acid dichlorofluoromethyl ester Dichlorofluoromethyl thiocyanate C2Cl2FNS C1 (gauche) Cs (anti) F

Bonds C(1)–S(2) S(2)–C(3) C(3)≡N(4) C(1)–F C(1)–Cl(1) C(1)–Cl(2) Bond angles C(1)–S(2)–C(3) S(2)–C(3)≡N(4) S(2)–C(1)–F S(2)–C(1)–Cl(1) S(2)–C(1)–Cl(2) F–C(1)–Cl(1) F–C(1)–Cl(2) Cl(1)–C(1)–Cl(2) Dihedral angle F–C(1)–S(2)–C(3)

re [Å] a,b gauche anti 1.815(13) 1 1.825(13) 1 2 1.684(8) 1.678(8) 2 3 1.160(5) 1.161(5) 3 4 1.338(5) 1.345(5) 4 5 1.754(4) 1.754(4) 5 5 1.761(4) 1.754(4) 5

S C N

Cl Cl

gauche

θe [deg] a,b

gauche 96.5(13) 6 177.1 c 110.6(3) 7 112.0(10) 8 107.2(24) 108.5(3) 7 109.4(3) 7 109.0(28) d

gauche 57.3(41)

anti 97.0(13) 6 177.1 c 103.3(3) 7 111.4(10) 8 111.4(10) 8 109.3(3) 7 109.3(3) 7 111.7(20) d

anti

τe [deg] a

anti 180.0 c

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from QC computation. c Fixed. d Dependent parameter. b

The GED experiment was carried out at Tnozzle of 300 and 315 K at the long and short nozzle-to-plate distances, respectively. The title compound was found to exist as a mixture of the gauche and anti conformers, characterized by the synclinal and antiperiplanar F−C−S−C dihedral angles, respectively, in the ratio gauche : anti = 79(11) : 21(11) (in %).

4 Molecules with Two Carbon Atoms

211

Vibrational corrections to the experimental innnternuclear distances, ∆re = ra − re, were estimated using the B3LYP/6-31G(d) quadratic and cubic force fields taking into account non-linear kinematic effects. Berrueta Martínez Y, Rodríguez Pirani LS, Erben MF, Boese R, Reuter CG, Vishnevskiy YV, Mitzel NW, Della Védova CO (2017) Gas and crystal structures of CCl2FSCN. J Mol Struct 1132:175-180

262 CAS RN: 354-24-5 MGD RN: 136817 MW supported by QC calculations

Chlorodifluoroacetyl chloride C2Cl2F2O C1 O

Cl

Distance Cl...Cl

rs [Å] a 3.4188(40)

Cl F

F

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit.

MP2/6-311+G(d) calculations predicted the existence of two conformers, anti and gauche, with antiperiplanar and synclinal Cl–C–C–Cl torsional angles, respectively; the anti conformer is higher in energy than the gauche one by 3.2 kJ mol-1. The rotational spectra of the chlorodifluoroacetyl chloride were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 8 and 16 GHz. Only the gauche conformer was observed in the spectra. The partial rs structure was determined from the ground-state rotational constants of four isotopic species (main, two 37Cl and 37Cl2). Grubbs GS, Dewberry CT, King A, Lin W, Bailey WC, Cooke SA (2010) Chlorine nuclear quadrupole coupling in chlorodifluoroacetyl chloride: Theory and experiment. J Mol Spectrosc 263(2):127-134

263 CAS RN: 5728-20-1 MGD RN: 363854 GED augmented by QC computations

3,4-Dichloro-1,2,5-thiadiazole C2Cl2N2S C2v S N

Bonds r1 b N(2)=C(3) C(3)–C(4) S−N C–Cl

rh1 [Å] a 1.674(1) 1.315(2) 1.434(5) c 1.642(2) c 1.706(2) c

Bond angles N−S−N S–N=C N=C–Cl N=C(3)–C(4)

θh1 [deg] a 99.1(2) 106.6(2) 121.5(2) 113.9(1) c

Cl

N

Cl

212

4 Molecules with Two Carbon Atoms

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Mean value of the S–N and C–Cl bond lengths. c Dependent parameter. b

The GED experiment was carried out at Tnozzle of 338 and 345 K at the short and long nozzle-to-camera distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using the MP2/6-31G(d) harmonic force constants. Schirlin JT, Wann DA, Bone SF, Robertson HE, Rankin DWH (2009) Additivity of ring geometry distortion effects in unsaturated five-membered heterocyclic rings. J Mol Struct 922 (1-3):103-108

264 CAS RN: 20233-04-9 MGD RN: 536898 GED augmented by QC computations

Thiocyanic acid trichloromethyl ester Trichloromethyl thiocyanate C2Cl3NS Cs Cl

N

Cl

Bonds C(1)–Cl(5) C(1)–Cl(6,6ʹ) C(1)–S(2) C(3)–S(2) C(3)≡N(4)

re [Å] a 1.765(2) b 1.757(2) b 1.826(2) b 1.691(13) 1.158(9)

Bond angles Cl(5)–C(1)–S(2) Cl(6)–C(1)–S(2) Cl(5)–C(1)–Cl(6,6ʹ) Cl(6)–C(1)–Cl(7) C(1)–S(2)–C(3) S(2)–C(3)≡N(4)

θe [deg] a

Dihedral angle Cl(6)–C(1)–S(2)–C(3)

τe [deg] a

rg [Å] a 1.774(2) 1.765(2) 1.839(2) 1.697(13) 1.163(9)

Cl

C S

101.4(7) 112.3(4) 110.6(10) 109.4(20) c 99.9(17) 177.1 d

61.9(12) c

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Differences in the C–Cl bond lengths and between the C–Cl and C(1)–S bond lengths were assumed at the values from CCSD(T)/cc-pVTZ computation. c Dependent parameter. d Adopted from computation as indicated above. b

The GED experiment was carried out at Tnozzle =316…318 K. The title molecule was found to exist as a single conformer with staggered orientation of the CCl3 group with respect to the SCN unit. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP/6-31G(d) quadratic and cubic force constants taking into account non-linear kinematic effects.

4 Molecules with Two Carbon Atoms

213

Comparison between the structures of the thiocyanates CH3SCN, CH2ClSCN and CCl3SCN has shown that the C–S bond lengths do not vary significantly. Berrueta Martínez Y, Rodríguez Pirani LS, Erben MF, Boese R, Reuter CG, Vishnevskiy YV, Mitzel NW, Della Védova CO (2016) Structures of trichloromethyl thiocyanate, CCl3SCN, in gaseous and crystalline state. ChemPhysChem 17 (10):1463-1467

265 CAS RN: 1354553-06-2 MGD RN: 308828 MW

Distances Rcm b I…C

r0 [Å] a 4.9644(12) 3.4281(12)

Angles

θ0 [deg] a

c

ϕ φd

Trifluoroiodomethane – carbon monoxide (1/1) C2F3IO C3v F

F C

F

O

I

4.0(5) 10(3)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the center-of-mass of CO subunit and the center-of-mass of CF3I subunit. c Angle between the C3 axis of CF3I subunit and Rcm. d Angle between the OC axis and Rcm. b

The rotational spectra of the binary complex of trifluoroiodomethane with carbon monoxide were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 7 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main, 13 C and 18O) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Stephens SL, Walker NR, Legon AC (2011) Rotational spectra and properties of complexes B⋅⋅⋅ICF3 (B = Kr or CO) and a comparison of the efficacy of ICl and ICF3 as iodine donors in halogen bond formation. J Chem Phys 135(22):224309/1-224309/8 doi:10.1063/1.3664314

266 CAS RN: 116-14-3 MGD RN: 359202 IR supported by ab initio calculations Bonds C=C C–F

r0 [Å] a 1.3134(39) b 1.3185(25)

Tetrafluoroethene Tetrafluoroethylene C2F4 D2h

r e [Å] a 1.3236(37) 1.3111(23) se

F

F

F

F

214

Bond angle C–C–F

4 Molecules with Two Carbon Atoms

θ0 [deg] a 123.57(16)

θ see [deg] a

123.29(16)

Reproduced with permission of AIP Publishing. a b

Parenthesized uncertainties in units of the last significant digit. rs value.

The rotationally resolved FTIR spectrum of the 13C isotopically enriched tetrafluoroethylene was recorded at 150 K at the Australian Synchrotron near 1170 and 1300 cm-1. The r0 structure was determined from the ground-state rotational constants of three isotopic species (main and two 13C). The semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Medcraft C, Fuss W, Appadoo DRT, McNaughton D, Thompson CD, Robertson EG (2012) Structural, vibrational, and rovibrational analysis of tetrafluoroethylene. J Chem Phys 137(21):214301/1-214301/11 [http://dx.doi.org/10.1063/1.4768417]

267 CAS RN: 2115127-44-9 MGD RN: 545300 MW supported by ab initio calculations

Bonds Ge–C C≡C

r0 [Å] a 1.952(1) 1.294 b

Bond angle C–Ge–C

θ0 [deg] a

2,3-Didehydro-1H-germiren-1-ylidene Germanium dicarbide C2Ge C2v Ge

38.7(2)

Reprinted with permission. Copyright 2017 American Chemical Society.

a b

Parenthesized uncertainty in units of the last significant digit is 1σ value. Dependent parameter.

The rotational spectra of the title compound were recorded in a supersonic jet by chirped-pulse FTMW and Balle-Flygare type FTMW spectrometers in the frequency region between 5 and 40 GHz. The gas sample was produced by laser ablation of a germanium carbide rod. The r0 structure was determined from the ground-state rotational constants of fourteen isotopic species (main, 70 Ge, 72Ge, 73Ge, 76Ge, 13C, 13C2, 70Ge/13C, 72Ge/13C, 73Ge/13C, 76Ge/13C, 70Ge/13C2, 72Ge/13C2 and 76Ge/13C2). The molecule was found to have a T-shaped structure. Zingsheim O, Martin-Drumel M.-A, Thorwirth S, Schlemmer S, Gottlieb CA, Gauss J, McCarthy MC (2017) Germanium dicarbide: Evidence for a T-shaped ground state structure. J Phys Chem Lett 8(16):3776-3781

268 CAS RN: 13092-75-6 MGD RN: 349614

Ethynylsilver Silver acetylide C2HAg

4 Molecules with Two Carbon Atoms

215

MW

C∞ v H

Distances Ag–C C≡C C–H

Ag

C

C

r0 [Å] a 2.007 1.227 1.052

Copyright 2013 with permission from Elsevier [a].

a

Uncertainties were not given in the original paper.

The rotational spectrum of ethynylsilver (1Σ+ electronic ground state) was recorded by a pulsed-jet FTMW spectrometer in the frequency range between 6 and 31 GHz and by a millimeter-wave spectrometer in the frequency range between 117 and 307 GHz. The transient species was produced by a DC discharge of acetylene together with laser-ablated silver atoms. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 109Ag, 109 Ag/D and D). a. Okabayashi T, Kubota H, Araki M, Kuze N (2013) Microwave spectroscopy of AgCCH and AuCCH in the X1Σ+ states. Chem Phys Lett 577:11-15 MW supported by ab initio calculations

Bonds Ag–C C≡C C–H

r0 [Å] a 1.9954(20) 1.2444(30) 1.0452(11)

rs [Å] a 2.000(3)

Reproduced with permission of AIP Publishing [b].

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of ethynylsilver (1Σ+ electronic ground state) were recorded in a supersonic jet by chirpedpulse and Balle-Flygare type FTMW spectrometers in the frequency region between 7 and 18.5 GHz. The compound was produced by a gas-phase reaction of laser-ablated silver with acetylene. The r0 and partial rs structures were determined from the ground-state rotational constants of four isotopic species (main, 109Ag, D and 109Ag/D). b. Stephens SL, Zaleski DP, Mizukami W, Tew DP, Walker NR, Legon AC (2014) Distortion of ethyne on coordination to silver acetylide, C2H2⋅⋅⋅AgCCH, characterized by broadband rotational spectroscopy and ab initio calculations. J Chem Phys 140(12):124310/1-124310/13 [http://dx.doi.org/10.1063/1.4868035]

269 CAS RN: 154427-22-2 MGD RN: 210689 MW

Ethynylaluminum Aluminum acetylide C2HAl C∞ v H

C

C

Al

216

Distances Al–C C≡C C–H

4 Molecules with Two Carbon Atoms

r0 [Å] a 1.963(5) 1.210(7) 1.060(3)

rs [Å] b 1.978 1.202 1.060

r m [Å] a 1.986(1) 1.2061(6) 1.0634(3) (1)

Copyright 2012 with permission from Elsevier [a].

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Uncertainties were not given in the original paper.

The rotational spectrum of the title compound (1Σ+ electronic ground state) was recorded by a pulsed-jet BalleFlygare type FTMW spectrometer in the frequency range between 4 and 60 GHz and by a millimeter/submillimeter-wave spectrometer in the range between 65 and 850 GHz. The transient species was produced by a DC discharge of acetylene or methane together with aluminum vapor. (1) The r0, rs and r m structures were determined from the ground-state rotational constants of five isotopic species (main, two 13C, 13C2 and D). a. Sun M, Halfen DT, Min J, Clouthier DJ, Ziurys LM (2012) Gas-phase rotational spectroscopy of AlCCH (X1Σ+): A model system for organo-aluminum compounds. Chem Phys Lett 553:11-16 MW augmented by ab initio calculations

Distances Al–C C≡C C–H

r e [Å] a 1.9570(1) 1.2223(2) 1.0650(1) se

Copyright 2014 with permission from Elsevier [b].

a

Parenthesized uncertainties in units of the last significant digit.

On the basis of the experimental ground-state rotational constants from the paper given above the semiexperimental equilibrium structure was determined by taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(Q+d)Z harmonic and anharmonic (cubic) force fields. b. Mück LA, Thorwirth S, Gauss J (2015) The semiexperimental equilibrium structures of AlCCH and AlNC. J Mol Spectrosc 311:49-53.

270 CAS RN: MGD RN: 210708 MW supported by ab initio calculations

2-Chloro-1,1-difluoroethene – argon (1/1) 2-Chloro-1,1-difluoroethylene – argon (1/1) C2HArClF2 C1 F

Cl

Ar

Distances C(1)…Ar C(2)…Ar F(1)…Ar

r0 [Å] a 3.8264(13) 3.6380(14) 3.4348(31)

F

H

4 Molecules with Two Carbon Atoms

Cl...Ar db

217

3.8895(34) 3.2785

Copyright 2014 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Distance between Ar and the ethylene plane.

The rotational spectrum of the binary van der Waals complex of 2-chloro-1,1-difluoroethylene with argon was recorded by broadband chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5.6 and 20.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 37 Cl, two 13C, D and 37Cl/D). The complex was found to be nonplanar with argon located in the FCCCl cavity. Leung HO, Marshall MD, Messinger JP, Knowlton GS, Sundheim KM, Cheung-Lau JC (2014) The microwave spectra and molecular structures of 2-chloro-1,1-difluoroethylene and its complex with the argon atom. J Mol Spectrosc 305:25-33

271 CAS RN: 196620-66-3 MGD RN: 404484 MW

Ethynylgold Gold acetylide C2HAu C∞ v H

Bonds Au–C C≡C C–H

C

C

Au

r0 [Å] a 1.903 1.212 b 1.055

Copyright 2013 with permission from Elsevier.

a b

Uncertainties were not given in the original paper. Assumed at the value for CuCCH.

The rotational spectrum of ethynylgold (1Σ+ electronic ground state) was recorded by a pulsed-jet FTMW spectrometer in the frequency range between 6 and 39 GHz and by a millimeter-wave spectrometer in the frequency range between 133 and 249 GHz. The transient species was produced by a DC discharge of acetylene together with laser-ablated gold atoms. The r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D). Okabayashi T, Kubota H, Araki M, Kuze N (2013) Microwave spectroscopy of AgCCH and AuCCH in the X1Σ+ states. Chem Phys Lett 577:11-15

272 CAS RN: 359-10-4 MGD RN: 596324 MW augmented by QC calculations

Bonds

r0 [Å] a

2-Chloro-1,1-difluoroethene 2-Chloro-1,1-difluoroethylene C2HClF2 Cs F

Cl

F

H

218

4 Molecules with Two Carbon Atoms

C=C C–F(1) C–F(2) C–H C–Cl

1.3029(87) 1.3211(87) 1.3195(33) 1.0826(30) 1.7311(69)

Bond angles C=C–F(1) C=C–F(2) C–C–H C–C–Cl

θ0 [deg] a

123.44(24) b 126.14(24) b 128.31(83) 121.3(11)

Copyright 2014 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Difference between the C=C–F angles was fixed to the value from MP2/6-311++G(2d,2p) calculations.

The rotational spectrum of the title compound was recorded by broadband chirped-pulse and Balle-Flygare type FTMW spectrometers in the region between 5.6 and 20.5 GHz. The r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 37Cl, two 13C, D and 37Cl/D). Leung HO, Marshall MD, Messinger JP, Knowlton GS, Sundheim KM, Cheung-Lau JC (2014) The microwave spectra and molecular structures of 2-chloro-1,1-difluoroethylene and its complex with the argon atom. J Mol Spectrosc 305:25-33

273 CAS RN: 844881-19-2 MGD RN: 409154 MW

Ethynylchromium Chromium acetylide C2HCr C∞ v Cr

Bonds Cr–C C≡C C–H

C

C

H

r0 [Å] a 1.993(6) 1.238 b 1.048 b

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainty in units of the last significant digit. Assumed equal to that in ZnCCH.

The rotational spectrum of ethynylchromium (6Σ+ electronic ground state) was recorded by a millimeter/submillimeter-wave spectrometer in the frequency region between 225 and 585 GHz. The radicals were produced by an AC discharge of chromiumhexacarbonyl and either methane or acetylene. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D). Min J, Ziurys LM (2016) Millimeter-wave spectroscopy of CrC (X3Σ-) and CrCCH (X6Σ+): Examining the chromium-carbon bond. J Chem Phys 144(18):184308/1-184308/8 [http://dx.doi.org/10.1063/1.4947247]

4 Molecules with Two Carbon Atoms

219

274 CAS RN: 16753-36-9 MGD RN: 213225 MW

Ethynylcopper Copper acetylide C2HCu C∞ v Cu

Bonds Cu–C C≡C C–H

r0 [Å] a 1.818(1) 1.212(2) 1.058(1)

rs [Å] b 1.819 1.213 1.058

C

C

H

r m [Å] a 1.8177(6) 1.2174(6) 1.046(2) (1)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Uncertainties were not given in the original paper.

The rotational spectrum of ethynylcopper (1Σ+ electronic ground state) was studied in a supersonic jet by the FTMW and direct absorption millimeter/submillimeter-wave methods in the frequency region between 7 and 305 GHz. The transient species was produced by a discharge assisted reaction of laser-ablated copper and acetylene. (1) The r0, rs and mass-dependent r m structures were determined from the ground-state rotational constants of six isotopic species (main, 65Cu, two 13C, 13C2 and D). Sun M, Halfen DT, Min J, Harris B, Clouthier DJ, Ziurys LM (2010) The rotational spectrum of CuCCH (X1Σ+): A Fourier transform microwave discharge assisted laser ablation spectroscopy and millimeter/submillimeter study. J Chem Phys 133(17):174301/1-174301/8 doi:10.1063/1.3493690

275 CAS RN: 139167-39-8 MGD RN: 113877 IR augmented by ab initio calculations

Distances Rcm c C(1)…H

Carbon monoxide – hydrogen cyanide (1/1) C2HNO C∞ v O

C

H

C

N

re [Å] a,b 4.842(1) 2.572(2)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. See comment for the significance of the structure. c Distance from the center-of-mass to the center-of-mass. b

The rotationally resolved vibrational spectrum of the binary complex was recorded by a quantum cascade cw supersonic jet spectrometer in the mid-IR region. The results of analysis of the ν2, ν2+ν71-ν71, ν2+ν71 and ν2+ν61 vibrational bands were used to fit a five-dimensional intermolecular PES. The presented structure corresponds to the global minimum of the semi-empirical PES.

220

4 Molecules with Two Carbon Atoms

McElmurry BA, Rivera-Rivera LA, Scott KW, Wang Z, Leonov II, Lucchese RR, Bevan JW (2012) Studies of low-frequency intermolecular hydrogen-bonded vibrations using a continuous supersonic slit jet mid-infrared quantum cascade laser spectrometer. Chem Phys 409:1-10

276 CAS RN: 886438-58-0 MGD RN: 408631 MW augmented by ab initio calculations

Bonds H–C(1) C(1)≡C(2) C(2)–N N=Si

(Ethynylimino)silylene C2HNSi C∞ v H

C

N

C

Si

r e [Å] a 1.0605(1) 1.2117(1) 1.3049(2) 1.5663(2) se

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 42 GHz. The transient species were produced by a pulsed discharge of methyl cyanide with silane. se The semiexperimental equilibrium structure r e was determined from the ground-state rotational constants of seven isotopic species (main, 29Si, 30Si, 15N, two 13C and D) taking into account rovibrational corrections calculated with the CCSD(T)/cc-pV(T+d)Z harmonic and anharmonic (cubic) force constants. Thorwirth S, Kaiser RI, Crabtree KN, McCarthy MC (2015) Spectroscopic and structural characterization of three silaisocyanides: exploring an elusive class of reactive molecules at high resolution. Chem Comm 51(56):11305-11308

277 CAS RN: 76092-43-8 MGD RN: 837580 MW augmented by ab initio calculations

Bonds H–N(1) N(1)≡C(2) C(2)–C(3) C(3)≡N(4)

Cyanomethylidyneammonium Protonated cyanogen C2HN2 C∞ v H

N

C

C

N

r see [Å] a 1.01321(6) 1.1407(1) 1.3723(1) 1.1634(1)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The semiexperimental equilibrium structure was determined from the previously published ground-state rotational constants of six isotopic species by taking into account rovibrational corrections calculated with the

4 Molecules with Two Carbon Atoms

221

CCSD(T)_ae/cc-pwCVQZ quadratic and cubic force fields. It was shown that the corrections calculated from the CCSD(T)/cc-pVTZ and CCSD(T)_ae/cc-pwCVQZ anharmonic force fields are negligibly different. Puzzarini C, Cazzoli G (2009) Equilibrium structure of protonated cyanogen, HNCCN+. J Mol Spectrosc 256(1):53-56

278 CAS RN: MGD RN: 350348 MW augmented by ab initio calculations

Hydroxyoxomethyl – carbon monoxide (1/1) C2HO3 Cs C O

Distances C(2)…H C(1)=O(1) C(1)–O(2) O(2)–H C(2)≡O(3)

r0 [Å] a 2.166 1.182 b 1.348 b 0.966 b 1.136 b

Angles O(1)=C(1)–O(2) C(1)–O(2)–H O(2)–H…C(2)

θ0 [deg] a

OH

C

O

127.1 b 107.6 b 176.8

Reproduced with permission of AIP Publishing.

a b

Uncertainties were not given in the original paper. Assumed at the value from CCSD(T)/aug-cc-pVTZ calculations.

The rotational spectrum of the binary complex of hydroxyoxomethyl with carbon monoxide was invetigated in the frequency region between 7 and 33.5 GHz by FTMW and by millimeter-wave FTMW double resonance spectroscopy. The complex was produced by an electrical discharge of carbon monoxide with water. Only one conformer was observed. The partial r0 structure was determined from the ground-state rotational constants of one isotopic species; the remaining structural parameters were fixed to ab initio values (see above). Oyama T, Sumiyoshi Y, Endo Y (2012) Pure rotational spectra of the CO-trans-HOCO complex.” J Chem Phys 137(15):154307/1-154307/6 [http://dx.doi.org/10.1063/1.4758528]

279 CAS RN: 1388217-95-5 MGD RN: 340392 MW supported by DFT calculations Bonds Zn–C C≡C

r0 [Å] a 1.902(3) 1.238(4)

Ethynylzinc Zinc acetylide C2HZn C∞ v Zn

r m [Å] a 1.9083(3) 1.2313(3) (1)

C

C

H

222

C–H

4 Molecules with Two Carbon Atoms

1.048(1)

1.0508(1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of ethynylzinc (2Σ+ electronic ground state) were measured in the frequency region between 7 and 260 GHz using the FTMW and millimeter-wave direct absorption methods. The transient species was produced by an electrical gas discharge of zinc vapor with acetylene. (1) The r0 and mass-dependent r m structures were determined from the rotational constants of five isotopic species 66 68 13 (main, Zn, Zn, D, C2). Min J, Halfen DT, Sun M, Harris B, Ziurys LM (2012) The microwave and millimeter spectrum of ZnCCH (X2Σ+): A new zinc-containing free radical. J Chem Phys 136(24):244310/1-244310/10 [http://dx.doi.org/10.1063/1.4729943]

280 CAS RN: 74-86-2 MGD RN: 630082 MW, IR augmented by ab initio calculations

Bonds C≡C C–H

Ethyne Acetylene C 2H 2 D∞ h H

C

C

H

r e [Å] a 1.202958(7) 1.06164(1) se

Reproduced with permission of AIP Publishing [a].

a

Parenthesized uncertainties in units of the last significant digit. se

The semiexperimental equilibrium structure r e was determined from the previously published ground-state rotational constants of ten isotopic species taking into account rovibrational corrections calculated with the CCSD(T)/cc-pwCVQZ harmonic and anharmonic (cubic) force fields. a. Lievin J, Demaison J, Herman M, Fayt A, Puzzarini C (2011) Comparison of the experimental, semiexperimental and ab initio equilibrium structures of acetylene: Influence of relativistic effects and of the diagonal Born-Oppenheimer corrections. J Chem Phys. 134(6):064119/1-064119/8 doi:10.1063/1.3553203 MW, IR

Bonds C≡C C–H

re [Å] a 1.202817(12) 1.061689(23)

Reproduced with permission from the PCCP Owner Societies [b].

4 Molecules with Two Carbon Atoms a

223

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The equilibrium structure re was determined from the experimental ground-state rotational constants of ten isotopic species and the experimental rotation-vibration interaction constants (for all normal modes). b.Tamassia F, Cané E, Fusina L, DiLonardo G (2016) The experimental equilibrium structure of acetylene. Phys Chem Chem Phys 18(3):1937-1944

Chloro(η2-ethyne)silver Silver chloride – acetylene (1/1) C2H2AgCl C2v

281 CAS RN: 1240710-08-0 MGD RN: 320368 MW supported by ab initio calculations

H C

a

Distances Ag–Cl C≡C C–H rc

r0 [Å] 2.2716(6) 1.2352(4) 1.9676 b 2.1831(8)

Angle C≡C–H

θ0 [deg] a

a

rs [Å] 2.2682 1.228(24)

2.1823

187.70(4)

(1) m

Ag

a

r [Å] 2.2658(3) 1.2220(20) 1.0669 b 2.1800(3)

Cl

C

H

θ (1) [deg] a m 187.79(1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Constrained to ab initio value. c Distance between Ag and the midpoint of the C≡C bond. b

The rotational spectra of the binary complex of silver chloride with acetylene were recorded in a supersonic jet both by a chirped-pulse and a Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The complex was produced by a gas phase reaction of laser-ablated silver with tetrachloromethane and acetylene. The obtained principal moments of inertia were interpreted in terms of a planar T-shaped structure. The partial (1) r0, rs and mass-dependent r m structures were determined from the ground-state rotational constants of eight 37 isotopic species (main, Cl, 13C2, 109Ag, D2, 109Ag/37Cl, 109Ag/13C2 and 109Ag/D2). The ethyne molecule distorts on complex formation by lengthening of the C≡C bond and movement of both H atoms away from the Ag atom. Stephens SL, Mizukami W, Tew DP, Walker NR, Legon AC (2012) Distortion of ethyne on formation of a π complex with silver chloride: C2H2⋅⋅⋅Ag–Cl characterized by rotational spectroscopy and ab initio calculations. J Chem Phys 137(17):174302/1-174302/13 [http://dx.doi.org/10.1063/1.4761895]

282 CAS RN: MGD RN: 328956 MW supported by ab initio calculations

(Z)-1-Chloro-2-fluoroethene – argon (1/1) cis-1-Chloro-2-fluoroethylene – argon (1/1) C2H2ArClF C1

224

4 Molecules with Two Carbon Atoms

Distances Ar…F Ar…Cl Ar…C(1) Ar...C(2) Ar...X b

r0 [Å] a 3.4578(25) 3.8458(28) 3.9014(15) 3.7567(15) 3.7729(15)

Angles

θ0 [deg] a

c

ϕ φd

H

H Ar

Cl

F

83.584(37) 59.77(11)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. X is the center of the C=C bond. c Angle between the C=C axis (z) and Ar…X. d Angle between the projection of Ar…X onto xy plane, which is perpendicular to the plane of chlorofluoroethylene subunit (xz plane), and the x axis. b

The rotational spectrum of the binary van der Waals complex was recorded in a supersonic jet by a chirped-pulse and a narrow-band Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 20 GHz. Only a nonplanar structure with the argon atom maximizing the number of its contacts with the heavy atoms of the ethylene subunit was consistent with the rotational constants of four isotopic species (main, two 13C and 37 Cl). The r0 structure was determined under the assumption that the structural parameters of the ethylene monomer subunit were not changed upon complexation. No evidence of tunneling between the two equivalent C1 structures with Ar on different sides of the ethylene plane was found. Marshall MD, Leung HO, Calvert CE (2012) Molecular structure of the argon-(Z)-1-chloro-2-fluoroethylene complex from chirped-pulse and narrow-band Fourier transform microwave spectroscopy. J Mol Spectrosc 280:97-103

283 CAS RN: 259823-60-4 MGD RN: 322583 MW supported by ab initio calculations

(Z)-1,2-Difluoroethene – argon (1/1) cis-1,2-Difluoroethylene – argon (1/1) C2H2ArF2 Cs H

H Ar

Distances Rcm b Ar…F

r0 [Å] a 3.38950(40) 3.4735(35)

Angle

θ0 [deg] a

φ

c

62.25(18)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Distance between Ar and the center-of-mass of the difluoroethylene subunit. c Angle between Rcm and the difluoroethylene plane towards the difluorine end. b

F

F

4 Molecules with Two Carbon Atoms

225

The rotational spectra of the binary van der Waals complex of cis-1,2-difluoroethylene with argon were recorded in a supersonic jet by a pulsed-jet FTMW spectrometer in the frequency region between 5.7 and 21.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 13C) under the assumption that the structural parameters of the difluoroethylene subunit were not changed upon complexation. Leung HO, Marshall MD, Mueller JL, Amberger BK (2013) The molecular structure of and interconversion tunneling in the argon-cis-1,2-difluoroethylene complex. J Chem Phys 139(13):134303/1-134303/8 [http://dx.doi.org/10.1063/1.4823494]

Iodo-(η2-ethyne)gold Ethyne – gold iodide (1/1) C2H2AuI C2v

284 CAS RN: 1808104-74-6 MGD RN: 438715 MW augmented by ab initio calculations

H

C a

Bonds Au–I C≡C rb C–H

r0 [Å] 2.507(4) 1.239(4) 2.057(15) 1.0692 c

rs [Å]

Bond angle C≡C–H

θ0 [deg] a

θs [deg] a

194.7(12)

1.264(4)

I

Au

a

C

H

1.038(2)

195.1(7)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Distance between Au and the center of the C≡C bond. c Assumed at the value obtained by correcting the calculated re value (CCSD(T)(F12*)/aug-cc-pVTZ(C,H), ccpVTZ-PP(Au,I)) for the difference between the experimentally measured r0 and re distances of C2H2. b

The rotational spectra of the binary complex of ethyne with gold iodide were recorded in a pulsed supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7.5 and 18 GHz. The transient species was produced by a gas-phase reaction of laser-ablated gold with ethyne and trifluoroiodomethane. The partial r0 and rs structures were determined from the ground-state rotational constants of three isotopic species (main, D2 and 13C2/D2). Mullaney JC, Stephens SL, Zaleski DP, Sprawling MJ, Tew DP, Walker NR, Legon AC (2015) An isolated complex of ethyne and gold iodide characterized by broadband rotational spectroscopy and ab initio calculations. J Phys Chem A 119(37):9636-9643

Chloro(η2-ethyne)copper Ethyne – copper(I) chloride (1/1) C2H2ClCu C2v

285 CAS RN: 45345-95-7 MGD RN: 341898 MW augmented by ab initio calculations

H C

Distances Cu–Cl

a

r0 [Å] 2.071(12)

a

rs [Å] 2.069(2)

Cu C H

Cl

226

4 Molecules with Two Carbon Atoms

C≡C Cu…X b C–H

1.2334(25) 1.888(15) 1.072 c

Angle X…C–H

θ0 [deg] a 192.4(7)

1.238(4) 1.887(2) 1.072 c

θs [deg] a 192.5(2)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. X is the midpoint of the C≡C bond. c Assumed at the CCSD(T)/aug-cc-pVTZ(F12*) value corrected for the difference between the experimentally measured r0 and re distances in ethyne. b

The rotational spectra of the binary complex of copper(I) chloride with ethyne were recorded in a supersonic jet both by a chirped-pulse and a Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The r0 and rs structures were determined from the ground-state rotational constants of five isotopic species (main, 37Cl, 13C2, D2 and 65Cu). The complex was found to have a T-shaped structure in which the Cu atom is bound to the π-electrons of ethyne. Stephens SL, Bittner DM, Mikhailov VA, Mizukami W, Tew DP, Walker NR, Legon AC (2014) Changes in the geometries of C2H2 and C2H4 on coordination to CuCl revealed by broadband rotational spectroscopy and abinitio calculations. Inorg Chem 53(19):10722-10730

286 CAS RN: 2317-91-1 MGD RN: 297190 MW supported by ab initio calculations

1-Chloro-1-fluoroethene 1-Chloro-1-fluoroethylene C2H2ClF Cs

Bonds C=C C–Cl C–F C–H(1) C–H(2)

r0 [Å] a 1.3267(26) 1.7042(22) 1.3412(28) 1.0803(11) 1.08192(90)

rs [Å] b 1.347(13) 1.7010(42) 1.312(90) 1.0810(17) 1.0824(14)

Bond angles C=C–Cl C=C–F C=C–H(1) C=C–H(2)

θ0 [deg] a

θs [deg] b

126.29(22) 121.75(28) 119.18(18) 119.35(14)

H

F

H

Cl

124.9(20) 121.4(19) 119.68(39) 118.89(38)

Copyright 2009 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Parenthesized uncertainties in units of the last significant digit are propagated from Costain errors.

4 Molecules with Two Carbon Atoms

227

The rotational spectrum of 1-chloro-1-fluoroethene was recorded by a pulsed molecular beam FTMW spectrometer in the spectral range between 7 and 22 GHz. The r0 and rs structures were determined from the ground-state rotational constants of eight isotopic species (main, 37Cl, two 13C, two 13C/37Cl and two D). Leung HO, Marshall MD, Vasta AL, Craig NC (2009) Microwave spectra of eight isotopic modifications of 1chloro-1-fluoroethylene. J Mol Spectrosc 253(2):116-121

287 CAS RN: 359-06-8 MGD RN: 386161 MW augmented by QC calculations

Fluoroacetyl chloride C2H2ClFO Cs O

Bonds F–C(2) C(2)–C(1) C(1)–Cl C(1)=O C(2)–H

r0 [Å] a 1.369(3) 1.511(3) 1.782(3) 1.186(3) 1.093(2)

Bond angles F–C(2)–C(1) C(2)–C(1)–Cl C(2)–C(1)=O Cl–C(1)=O F–C(2)–H H–C(2)–H H–C(2)–C(1)

θ0 [deg] a

Dihedral angles F–C(2)–C(1)–Cl F–C(2)–C(1)–H

τ0 [deg] a

F Cl

110.4(5) 109.7(5) 127.4(5) 122.9(5) 109.8(5) 109.4(5) 108.7(5)

180.0 120.5(5)

Copyright 2015 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of the anti conformer was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 16 and 22 GHz. The r0 structure was determined by adjusting the MP2_full/6-311+G(d,p) structure to the experimental groundstate rotational constants of two isotopic species (main and 37Cl). Three conformers, anti, gauche and syn, characterized by the different F–C–C–Cl torsional angles, were identified in the temperature-dependent IR and Raman vibrational spectra and their amounts were estimated for ambient temperature to be 56(1), 26(1) and 17(3) %, respectively. Deodhar BS, Brenner RE, Klaassen JJ, Tubergen MJ, Durig JR (2015) Microwave, structural, conformational, vibrational studies and ab initio calculations of fluoroacetyl chloride. Spectrochim Acta A 148:289-298

288

1-Chloro-2,2,2-trifluoroethane

228

4 Molecules with Two Carbon Atoms

CAS RN: 75-88-7

MGD RN: 342190 MW augmented by ab initio calculations

C2H2ClF3 F

F

Cs Cl

Bonds

F

C–Cl C–C C–F(1) C–F(2) C–H

r e [Å] a 1.7637(4) 1.5099(10) 1.3429(12) 1.3294(11) 1.0856 b

Angles

θ see [deg] a

C–C–Cl C–C–F F(2)–C–F(2ꞌ) H–C–H H–C–C

φc ϕd

se

111.28(6) 108.64(15) 108.15(14) 110.212 b 108.450 b 130.11(12) 123.588 b

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Assumed according to the MP2/aug-cc-pVDZ value with empirical correction. c Angle between the bisector of the F(2)–C–F(2ꞌ) angle and the C–C bond. d Angle between the bisector of the H–C–H angle and the C–C bond. b

The rotational spectrum of 1-chloro-2,2,2-trifluoroethane was recorded in a supersonic jet by chirped-pulse and cavity FTMW spectrometers in the frequency region between 8 and 18 GHz as well as at room temperature by a broadband millimeter-wave spectrometer in the region between 94 and 309 GHz. se The semiexperimental equilibrium structure r e was determined from the ground-state rotational constants of six 13 37 isotopic species (main, four C and Cl) taking into account rovibrational corrections calculated with the MP2/aug-cc-pVDZ harmonic and anharmonic (cubic) force fields. Uriarte I, Kisiel Z, Białkowska-Jaworska E, Pszczółkowski L, Ecija P, Basterretxea FJ, Cocinero EJ (2017) Comprehensive rotational spectroscopy of the newly identified atmospheric ozone depleter CF3CH2Cl. J Mol Spectrosc 337(1):37-45

289 CAS RN: MGD RN: 453792 MW augmented by ab initio calculations

Distances Rcm b F(3)…H(7) F(8)…H(4) Cl...H(5) C(1)...C(6)

r0 [Å] a 3.661(2) 2.633 c 2.861 c 3.169 c 3.661 c

Difluoromethane – chlorofluoromethane (1/1) C2H2ClF3 C1 H

F

H

H

F

Cl

H

F

4 Molecules with Two Carbon Atoms

Angles F(3)–C(1)…C(6) Cl–C(6)…C(1)

229

θ0 [deg] a 59.2(1) 82.8(1)

Reproduced with permission from the Centre National de la Recherche Scientifique (CNRS) and The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Dependent parameter. b

The rotational spectra of the binary complex of difluoromethane with chlorofluoromethane were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl); the remaining structural parameters were constrained to their MP2/6-311++G(d,p) ab initio values. Spada L, Gou Q, Tang S, Caminati W (2015) Weak hydrogen bonds in adducts between freons: the rotational study of CH2F2-CH2ClF. New J Chem 39(3):2296-2299

290 CAS RN: MGD RN: 209630 MW supported by ab initio calculations

1,1,2-Trifluoroethene – hydrogen chloride (1/1) Trifluoroethylene – hydrogen chloride (1/1) C2H2ClF3 Cs F

F H

a

Distances H(1)...F H(2)...Cl

r0 [Å] 2.3416(7) 3.0796(5)

Angles C(2)–F…H(1) Cl–H(1)…F

θ0 [deg] a

F

Cl

H

109.720(39) 132.271(13)

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the binary complex of trifluoroethylene with hydrogen chloride was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 20 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Leung HO, Marshall MD, Ray MR, Kang JT (2010) Rotational spectroscopy and molecular structure of the 1,1,2-trifluoroethylene-hydrogen chloride complex. J Phys Chem A 114(41):10975-10980

291

Chlorotrifluoroethene – water (1/1)

230

4 Molecules with Two Carbon Atoms

CAS RN: MGD RN: 410269 MW augmented by ab initio calculations

C2H2ClF3O C1 F

Cl O H

a

Bonds C(1)–C(2) C(2)–F C(2)–Cl C(1)–F C(1)…O O–H

r0 [Å] 1.332 b 1.336 b 1.700 b 1.316 b 2.947(3) 0.960 b

Angles F–C(2)–C(1) Cl–C(2)–C(1) F–C(1)–C(2) O…C(1)–C(2) H–O…C(1)

θ0 [deg] a

F

H

F

120.0 b 115.8 b 123.5 b 100.5(1) 120.9 b

Dihedral angle τ0 [deg] a O…C(1)–C(2)–F -89.4(2) Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission. a b

Parenthesized uncertainty in unit of the last significant digit. Assumed at the value from MP2/6-311++G(d,p) calculations.

Rotational spectra were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 37 Cl, 18O, D and D2); the remaining structural parameters were assumed at the values from ab initio calculations (see above). The detected structure is stabilized by lp… π interaction, where lp is the electron lone pair on oxygen. Gou Q, Feng G, Evangelisti L, Caminati W (2013) Lone-pair⋅⋅⋅π interaction: A rotational study of the chlorotrifluoroethylene-water adduct. Angew Chem 125(45):12104-12107; Angew Chem Int Ed 52(45):1188811891 292 CAS RN: 3268-79-9 MGD RN: 466610 GED augmented by QC computations

Thiocyanic acid chloromethyl ester Chloromethyl thiocyanate C2H2ClNS C1 (gauche) Cs (anti) N

Bonds C(1)–S(2) S(2)–C(3) C(3)–N(4) C(1)–Cl C(1)–H(6) C(1)–H(7)

gauche 1.805(2) 1 1.691(4) 2 1.159(3) 3 1.766(2) 1 1.081 c 1.083 c

re [Å]

a,b

anti 1.821(2) 1 1.692(4) 2 1.159(3) 3 1.762(2) 1 1.081 c 1.081 c

C Cl

S

4 Molecules with Two Carbon Atoms

231

θe [deg] a,b

Bond angles

gauche 99.8(15) 5 178.2 c 113.5(3) 6 108.5(13) 6 104.1(13) 6 107.4(13) 6 107.5(13) 6 116.1(54) d

C(1)–S(2)–C(3) S(2)–C(3)–N(4) S(2)–C(1)–Cl S(2)–C(1)–H(6) S(2)–C(1)–H(7) Cl–C(1)–H(6) Cl–C(1)–H(7) H(6)–C(1)–H(7) Dihedral angle Cl–C(1)–S(2)–C(3)

gauche 71.8(39)

anti 96.5(35) 5 179.6 c 91.4(19) 6 108.7(13) 6 108.7(13) 6 107.9(13) 6 107.9(13) 6 126.6(41) d

gauche

τe [deg] a

anti 180.0 c anti

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the value from CCSD(T)/cc-pVTZ computation. c Assumed at the value from computation as indicated above. d Dependent parameter. b

The existence of two conformers, gauche and anti, with the synclinal and antiperiplanar Cl–C(1)–S(2)–C(3) torsional angles, respectively, was predicted by computations at the MP2_full and B3LYP levels of theory in conjunction with cc-pVTZ basis set. In the GED analysis (Tnozzle = 336…338 K), the ratio of the conformers was determined to be gauche : anti = 89(3) : 11(3) (in %). The abundances of these conformers estimated from the free Gibbs energy difference (MP2) are 85 and 15 %, respectively, being in agreement with the experimental values. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated using quadratic and cubic force constants from B3LYP/6-31G(d) and O3LYP/cc-pVTZ computations and taking into account non-linear kinematic effects. According to NBO analysis, the relative destabilization of the anti conformer and elongation of its S–C bond occurs mainly due to more strong repulsion of the electron lone pairs on Cl and S atoms in comparison to that in the gauche conformer. Berrueta Martinez Y, Rodríguez Pirani LS, Erben MF, Reuter CG, Vishnevskiy YV, Stammler HG, Mitzel NW, Della Védova CO (2015) The structure of chloromethyl thiocyanate, CH2ClSCN, in gas and crystalline phases. Phys Chem Chem Phys 17 (24):15805-15812

(η2-Ethyne)fluorocopper Copper(I) fluoride – acetylene (1/1) C2H2CuF C2v

293 CAS RN: 212852-35-2 MGD RN: 456942 MW supported by ab initio calculations

H C

Distances C≡C C–H Cu…X c Cu–F

a

r0 [Å] 1.2461(1) 1.07041 b 1.8474(7) 1.7547(9)

Cu

a

rs [Å] 1.24(4) 1.077(4) 1.85(1) 1.751(10)

C H

F

232

Angle H–C≡C

4 Molecules with Two Carbon Atoms

θ0 [deg] a

194.65(2)

θs [deg] a 194.5(6)

Reproduced with permission from the PCCP Owner Societies. a

Parenthesized uncertainties in units of the last significant digit. Assumed. c X is the midpoint of the C≡C bond. b

The rotational spectra of the binary complex of copper(I) fluoride with acetylene were investigated in a supersonic jet both by a chirped-pulse and by a Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The transient species was produced by a reaction of laser-ablated copper with a gas pulse of acetylene and sulfur hexafluoride. The r0 and rs structure were determined from the ground-state rotational constants of six isotopic species (main, 65 Cu, 13C2, D2, 65Cu/13C2 and 65Cu/D2). Zaleski DP, Stephens SL, Tew DP, Bittner DM, Walker NR, Legon AC (2015) Distortions of ethyne when complexed with a cuprous or argentous halide: the rotational spectrum of C2H2⋅⋅⋅CuF. Phys Chem Chem Phys 17(29):19230-19237

294 CAS RN: 75-38-7 MGD RN: 169180 MW and IR augmented by ab initio calculations Bonds C=C C–H C–F

r e [Å] a 1.3175(3) 1.0754(1) 1.3157(2)

Bond angles C=C–H H–C–H C=C–F F–C–F

θ see [deg] a

se

1,1-Difluoroethene Vinylidene fluoride C2H2F2 C2v H

F

H

F

119.40(1) 121.21(2) 125.16(2) 109.68(2)

Reprinted with permission. Copyright 2009 American Chemical Society [a].

a

Parenthesized uncertainties in units of the last significant digit.

Rotationally resolved spectra of mono- and dideuterated 1,1-difluoroethylene were recorded by an FTIR spectrometer in the region between 350 and 4000 cm-1. Moreover, five isotopic species (including both 13C and both deuterated isotopic species) were reinvestigated by pulsed-beam FTMW spectroscopy in the region between 10 and 22.5 GHz. se The semiexperimental equilibrium structure r e was determined from the experimental ground-state rotational 13 constants of five isotopic species (main, two C, D and D2). The rovibrational corrections, ΔBe = Be ‒ B0, were calculated with the MP2/aug-cc-pVTZ harmonic and anharmonic (cubic) force constants.

4 Molecules with Two Carbon Atoms

233

a. McKean DC, Law MM, Groner P, Conrad AR, Tubergen MJ, Feller D, Moore MC, Craig NC (2010) Infrared spectra of CF2=CHD and CF2=CD2: scaled quantum-chemical force fields and an equilibrium structure for 1,1difluoroethylene. J Phys Chem A 114(34):9309-9318 MW, IR augmented by ab initio calculations

C2v

Bonds C=C C–H C–F

r see [Å] a 1.3175(3) 1.0752(1) 1.3158(2)

Bond angles C=C–H F–C–F

θ see [deg] a

119.409(7) 109.694(10)

Copyright 2014 Wiley Periodicals. Inc.. Reproduced with permission [b].

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure was determined from the previously published ground-state rotational constants of five isotopic species accounting for rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVQZ harmonic and anharmonic (cubic) force constants. It was shown that the magnitude of these corrections is quite sensitive to the level of force field calculations, whereas the structure is not sensitive to systematic errors of the equilibrium rotational constants, if the leastsquares system is well conditioned. b. Vogt N, Demaison J, Vogt J, Rudolph HD (2014) Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method: structure of molecules containing the OH or the CH3 group. J Comput Chem 35(32):2333-2342

295 CAS RN: 1073076-55-7 MGD RN: 212394 MW supported by ab initio calculations

Difluoromethane – carbonyl sulfide (1/1) C2H2F2OS Cs H

H O

a

a

Distances C…C O…H C=S

r0 [Å] 3.58(2) 2.88(3)

rs [Å] 3.548(2)

Angles C...C=O C...C=S C…C–H

θ0 [deg] a

θs [deg] a

65.0(5) 79(2)

1.568(3)

65.3(2) 114.7(2)

Reprinted with permission. Copyright 2008 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit.

F

F

C

S

234

4 Molecules with Two Carbon Atoms

The rotational spectra of the binary complex of difluoromethane with carbonyl sulfide were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 15 GHz. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, two 13 C and 34S) under the assumption that the structural parameters were not changed upon complexation. The experimental planar moments indicated that the two F atoms straddle the symmetry plane while one C–H bond is aligned to interact with the O atom. Serafin MM, Peebles SA (2008) Dimers of fluorinated methanes with carbonyl sulfide: The rotational spectrum and structure of difluoromethane-OCS. J Phys Chem A 112(49):12616-12621

296 CAS-RN: 500570-45-6 MGD RN: 342270 MW supported by ab initio calculations

Difluoromethane – carbon dioxide (1/1) C2H2F2O2 Cs (see comment) F

F

Distance C…C

r0 [Å] a 3.476(6)

rs [Å] a 3.434(2)

Angles C…C–H O=C…C

θ0 [deg] a

θs [deg] a

85.5(10) 71.3(4)

O

O

C

H

H

69.9(2)

Copyright 2013 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the binary complex of difluoromethane with carbon dioxide was recorded by chirpedpulse and Balle-Flygare type FTMW spectrometers in the frequency region between 7 and 15 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, two 13C, two 18O and 18O2), under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. A doubling of all rotational transitions was assigned to the rocking of the CH2F2 subunit between two equivalent positions via a C2v transition state. Thomas AJ, Serafin MM, Ernst AA, Peebles RA, Peebles SA (2013) An investigation of the structure and large amplitude motions in the CH2F2⋅⋅⋅CO2 weakly bound dimer. J Mol Spectrosc 289:65-73

297 CAS RN: 1784715-50-9 MGD RN: 456327 MW supported by ab initio calculations

2,2,2-Trifluoroacetonitrile – water (1/1) C2H2F3NO Cs F

F O

Distances N…H O…C b

r0 [Å] a 2.075 3.135

Reproduced with permission from the PCCP Owner Societies.

F

H

C N

H

4 Molecules with Two Carbon Atoms

a b

235

Uncertainties were not given in the original paper. Trifluoromethyl group.

The rotational spectrum of the binary complex of trifluoroacetonitrile with water was recorded in a supersonic jet by a pulsed-nozzle FTMW spectrometer in the frequency region between 16 and 19 GHz. The partial r0 structure was determined from the obtained ground-state rotational constants under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Lin W, Wu A, Lu X, Tang X, Obenchain DA, Novick SE (2015) Internal dynamics in the molecular complex of CF3CN and H2O. Phys Chem Chem Phys 17(26):17266-17270

298 CAS RN: 288-37-9 MGD RN: 477673 MW augmented by ab initio calculations

1,2,5-Oxadiazole Furazan C2H2N2O C2v N

Bonds N–O N=C C–C C–H

r e [Å] a 1.3665(5) 1.3020(6) 1.419(2) b 1.0742(5)

Bond angles

θ see [deg] a

N–O–N O–N=C N=C–C N=C–H C–C–H

N O

se

111.28(5) 105.61(6) 108.75(5) b 121.02(8) 130.23(4)

Reprinted with permission. Copyright 2011 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. se

The semiexperimental equilibrium structure r e of furazan was determined from the previously published experimental ground-state rotational constants of nine isotopic species taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Demaison J, Császár AG, Margulès LD, Rudolph HD (2011) Equilibrium structures of heterocyclic molecules with large principal axis rotations upon isotopic substitution. J Phys Chem A 115(48):14078-14091

299 CAS RN: 288-99-3 MGD RN: 298345 MW augmented by

1,3,4-Oxadiazole C2H2N2O C2v

236

4 Molecules with Two Carbon Atoms

DFT calculations

Bonds

N

C–O C=N N–N C–H

r e [Å] a 1.3548(16) 1.2840(11) 1.4058(13) 1.0734(13)

Bond angles

θ see [deg] a

C–O–C O–C=N C=N–N O–C–H N=C–H

N

O

se

101.29(12) 113.7820(20) 105.572(60) 118.0810(20) 128.1370(29)

Reprinted with permission. Copyright 2013 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of 1,3,4-oxadiazole was recorded in a supersonic jet by two Balle-Flygare type FTMW spectrometers in the frequency region between 2 and 26 GHz. se The semiexperimental equilibrium structure r e was determined from the ground-state rotational constants of 15 13 18 five isotopic species (main, N, C, O and D). The required rovibrational corrections, ΔBe = Be ‒ B0, were calculated with the B3LYP/6-311+G(3df,2pd) quadratic and cubic force fields. Demaison J, Jahn MK, Cocinero EJ, Lesarri A, Grabow JU, Guillemin JC, Rudolph HD (2013) Accurate semiexperimental structure of 1,3,4-oxadiazole by the mixed estimation method. J Phys Chem A 117(10):22782284

300 CAS RN: 463-51-4 MGD RN: 244539 MW augmented by ab initio calculations

H

C

Bonds C=O C=C C–H

r0 [Å] a 1.1628(101) 1.3145(106) 1.0788(22)

rs [Å] a 1.162(5) 1.3136(56) 1.0795(17)

rm [Å] a 1.1617(4) 1.3149(6) 1.1617(4)

Bond angle H–C=C

θ0 [deg] a

θs [deg] a

θm [deg] a

118.80(20)

Ethenone Ketene C2H2O C2v

118.9(30)

118.72(2)

r see [Å] a 1.1607(6) 1.3122(6) 1.0763(1)

C

O

H

θ see [deg] a

119.115(11)

Copyright 2009 with permission from Elsevier [a].

a

Parenthesized uncertainties in units of the last significant digit.

The r0, rs and rm structures were determined from the previously published ground-state rotational constants of twelve isotopic species. The semiexperimental equilibrium structure r see was obtained taking into account rovibrational corrections calculated with the MP2/cc-pVTZ quadratic and cubic force fields.

4 Molecules with Two Carbon Atoms

237

a. Guarnieri A, Demaison J, Rudolph HD (2010) Structure of ketene – Revisited re (equilibrium) and rm (massdependent) structures. J Mol Struct 969(1-3):1-8 GED augmented by ab initio computations

C2v

Bonds C=O C=C C–H

rh1 [Å] a 1.154(3) b 1.323(2) b 1.085(1) b

Bond angles H–C=C H–C–H

θh1 [deg] a

119.4(5) b 121.3(10) c

Reprinted with permission. Copyright 2016 American Chemical Society [b].

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Constrained to the value from MP2/6-311++G** calculation. c Dependent parameter. b

The GED experiment for the pyrolysis products of acetic anhydride, namely ketene and acetic acid, was carried out with a maintained temperature of 823 K. It was assumed that ketene and acetic acid were generated in the ratio of 67:33 (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from computation at the level of theory indicated above. b. Atkinson SJ, Noble-Eddy R, Masters SL (2016) Gas-phase structures of ketene and acetic acid from acetic anhydride using very-high-temperature gas electron diffraction. J Phys Chem A 120 (12):2041-2048

301 CAS RN: 1374752-90-5 MGD RN: 450384 MW supported by ab initio calculations

Formic acid – carbon dioxide (1/1) C 2H 2O 4 Cs

O O

Distances H(5)…O(6) C(7)…O(3)

r0 [Å] 2.075 a 2.877 a

Angles O(6)…O(4)–C(2) C(7)=O(6)…O(4) O(6)=C(7)…O(3) C(7)=O(6)…H(5) O(6)…H(5)–O(4) C(2)=O(3)…C(7)

θ0 [deg]

94.49(2) b 114.60(2)b 87 a 120 162 a 119 a

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

H

OH

C

O

238 a b

4 Molecules with Two Carbon Atoms

Uncertainty was not given in the original paper. Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of the title complex was recorded in the frequency ranges 6.5 - 18.5 and 59.6 - 74.4 GHz using a pulsed-jet FTMW spectrometer and a millimeter-wave Stark modulated free-jet absorption spectrometer, respectively. The complex was estimated to be planar. The subunits held together by the OH(5)…O(6)= and =O(3)…CO2 interactions. The partial r0 structure was determined from the ground-state rotational constants of the three isotopic species (main and two D). Vigorito A, Gou Q, Calabrese C, Melandri S, Maris A, Caminati W (2015) How CO2 interacts with carboxylic acids: a rotational study of formic acid-CO2. ChemPhysChem 16(14):2961-2967

302 CAS RN: 190248-21-6 MGD RN: 128504 MW

Acetonitrile – argon (1/1) C2H3ArN Cs

H H

Distance Rcm b

r0 [Å] a 3.650(3)

Angle

θ0 [deg] a

ϕ

c

C

N

Ar

H

95.7(16)

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit. Distance between Ar and the center-of-mass of acetonitrile. c Angle between Rcm and the C3 axis of acetonitrile. b

The rotational spectrum of the binary van der Waals complex of acetontrile with Ar was recorded by a pulsedbeam FTMW spectrometer in the frequency region between 9 and 22 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main, 13 C and 15N) under the assumption that the structural parameters of acetonitrile were not changed upon complexation. Lovas FJ, Sobhanadri J (2015) Microwave rotational spectral study of CH3CN-H2O and Ar-CH3CN. J Mol Spectrosc 307:59-64

303 CAS RN: 145949-06-0 MGD RN: 133551 MW augmented by ab initio calculations

Ethylidynearsine C2H3As C3v H H

Bonds

r

se e

[Å]

a

C

H

As

4 Molecules with Two Carbon Atoms

C≡As C–C C–H

1.6585(2) 1.4634(2) 1.0910(3)

Bond angle

θ see [deg] a

H–C–C

239

110.575(10)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see was determined from the previously published ground-state rotational constants of eight isotopic species taking into account rovibrational corrections calculated with the MP2/SDB-cc-pVTZ harmonic and anharmonic (cubic) force fields. Demaison J, Møllendal H., Guillemin JC (2009) Equilibrium CAs and CSb bond lengths. J Mol Struct 930(13):21-25

304 CAS RN: 90350-94-0 MGD RN: 372076 GED augmented by ab initio computations

Bonds C–H C=C As–X c As–C As–Cl

rh1 [Å] a 1.085(9) b 1.355(15) 2.065(6) d 1.944(10) e 2.184(6) e,f

Bond angles C(1)=C(2)–H C(2)=C(1)–H C=C–As C–As–Cl Cl–As–Cl

θh1 [deg] a

Ethenylarsenous dichloride Dichlorovinylarsine C2H3AsCl2 Cs Cl H 2C

As Cl

121.7(9) b 122.6(9) b 119.7(12) 97.1(6) 98.6(9) b

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Restrained to the value from MP2/6-311++G** computation. c X = C, Cl. d Average value. e Dependent parameter. f Difference to rh1(As–Cl) in AsCl3 was restrained to the value from computations as indicated above. b

The GED experiment was carried out at the nozzle temperature of 293 K. The sample was found to contain also AsCl3 (48(3)%). The title molecule was found to exist as a single conformer with the anticlinal C=C–As–Cl torsional angles (Cs point-group symmetry); the amount of the second

240

4 Molecules with Two Carbon Atoms

conformer (C1 point-group symmetry), characterized by the synperiplanar and anticlinal C=C–As–Cl dihedral angles, was refined to be zero. According to results of MP2 computations, the second conformer is higher in energy relative to the lowest-energy conformer by up to 10 kJ mol–1. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/6-31+G* computation. Noble-Eddy R, Masters SL, Rankin DWH, Robertson HE, Guillemin JC (2010) Molecular structures of vinylarsine, vinyldichloroarsine and arsine studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 978 (1-3):26-34

305 CAS RN: MGD RN: 215857 MW supported by ab initio calculations

1-Chloro-1-fluoroethene – hydrogen fluoride (1/1) 1-Chloro-1-fluoroethylene – hydrogen fluoride (1/1) C2H3ClF2 Cs Cl

H

H

Distances F(1)…H(2) F(2)…H(1)

r0 [Å] a 1.9482(10) 2.7386(19)

Angles C–F(1)…H(2) F(2)–H(2)…F(1)

θ0 [deg] a

F

F

H

124.371(70) 150.86 b

Copyright 2011 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Fixed at the value derived from the nuclear spin-spin coupling constant.

The rotational spectrum of the binary complex was recorded by a pulsed molecular beam FTMW spectrometer in the spectral region between 8 and 22 GHz. The r0 structure was obtained from the ground-state rotational constants of six isotopic species (main, 37Cl, two 13 C, D and 37Cl/D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The complex is formed due to hydrogen bonding interaction between the H(2) donor and the F(1) acceptor as well as due to interaction between the H(1) and F(2). Leung HO, Marshall MD, Bozzi AT, Cohen PM, Lam M (2011) Microwave spectrum and molecular structure of the 1-chloro-1-fluoroethylene-hydrogen fluoride complex. J Mol Spectrosc 267(1-2):43-49

306 CAS RN: 2009091-92-1 MGD RN: 216450 MW supported by ab initio calculations

(E)-1-Chloro-2-fluoroethene – hydrogen fluoride (1/1) trans-1-Chloro-2-fluoroethylene – hydrogen fluoride (1/1) C2H3ClF2 Cs H

F H

Distances H(1)…F(2) H(2)…F(1)

a

r0 [Å] 2.4510(26) 1.9399(19)

Cl

H

F

4 Molecules with Two Carbon Atoms

Angles C–F(1)…H(2) F(1)…H(2)–F(2)

241

θ0 [deg] a

118.200(55) 155.25

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of the binary complex of (E)-1-chloro-2-fluoroethene with hydrogen fluoride were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6.9 and 21.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, 37 Cl, three D and three 37Cl/D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Leung HO, Marshall MD, Lee AJ (2016) The microwave spectrum and molecular structure of (E)-1-chloro-2fluoroethylene-HF: Revealing the balance among electrostatics, sterics, and resonance in intermolecular interactions. J Phys Chem A 120(40):7935-7946

307 CAS RN: MGD RN: 451135 MW augmented by ab initio calculations

Chlorotrifluoroethene – ammonia (1/1) Chlorotrifluoroethylene – ammonia (1/1) C2H3ClF3N C1 Cl

F

N H

Distance N(7)…C(2)

r0 [Å] a 2.987(2)

Angles N(7)…C(2)=C(1) N(7)…C(2)=C(1)–Cl(3) X…N(7)…C(2) b X…N(7)…C(2)=C(1)

θ0 [deg] a

F

F

H H

100.9(1) 88.3(1) 166.1(1) 138.6(1)

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit. X is a dummy atom on the C3 axis of the ammonia subunit.

The rotational spectra of the binary complex of chlorotrifluoroethene with ammonia were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 37 Cl, 15N and D3); the remaining structural parameters were constrained to their MP2/aug-cc-pVDZ values. Gou Q, Spada L, Geboes Y, Herrebout WA, Melandri S, Caminati W (2015) N lone-pair⋅⋅⋅π interaction: a rotational study of chlorotrifluoroethylene⋅⋅⋅ammonia. Phys Chem Chem Phys 17(12):7694-7698

308

Chlorotrifluoromethane – fluoromethane (1/1)

242

4 Molecules with Two Carbon Atoms

CAS RN: MGD RN: 416471 MW augmented by ab initio calculations

Distance F…Cl

C2H3ClF4 C1 F

F

r0 [Å] a 2.995

F

H

H

Cl

H

F

Reprinted with permission. Copyright 2014 American Chemical Society. a

Uncertainty was not given in the original paper.

The rotational spectra of the binary complex of chlorotrifluoromethane with fluoromethane were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 37Cl, D3 and 37 Cl/D3); the remaining structural parameters were fixed to the values from MP2/6-311++G(d,p) calculations. Both monomer subunits exhibit free or almost free internal rotations in the halogen-bonded complex. Gou Q, Spada L, Cocinero EJ, Caminati W (2014) Halogen-halogen links and internal dynamics in adducts of freons. J Phys Chem Lett 5(9):1591-1595

309 CAS RN: MGD RN: 498054 MW supported by ab initio calculations

(E)-1-Chloro-2-fluoroethene – hydrogen chloride (1/1) trans-1-Chloro-2-fluoroethylene – hydrogen chloride (1/1) C2H3Cl2F essentially Cs H

F H

Distances H(1)…Cl(2) H(2)…F

r0 [Å] a 2.9011(5) 2.19481(34)

Angles C–F…H(2) F–H(2)…Cl(2)

θ0 [deg] a

Cl

Cl

H

122.23297(95) 152.63

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the binary complex of (E)-1-chloro-2-fluoroethene with hydrogen chloride were recorded in a supersonic jet both by a broadband chirped-pulse FTMW and a Balle-Flygare type FTMW spectrometer in the frequency region between 5.6 and 20 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main and three 37Cl) under the assumption that the structural parameters were not changed upon complexation. Leung HO, Marshall MD (2016) Effect of chlorine substitution in modulating the relative importance of two intermolecular interactions: The microwave spectrum and molecular structure of (E)-1-chloro-2-fluoroethyleneHCl. J Phys Chem A 120(40):7955-7963

4 Molecules with Two Carbon Atoms

310 CAS RN: 4109-83-5 MGD RN: 368794 GED augmented by QC computations

243

Trichloroethenylgermane Trichlorovinylgermane C2H3Cl3Ge Cs Cl

H 2C

a

Bonds Ge–C(2) C(2)=C(3) C(2)–H(6) C(3)–H(4) C(3)–H(5) Ge–Cl(7) Ge–Cl(8)

ra [Å] 1.917(5) 1.349(5) 1.118(10) 1.118 b 1.116 b 2.127(2) 2.127 c

Bond angles Ge–C(2)=C(3) C(3)=C(2)–H(6) C(2)=C(3)–H(4) C(2)=C(3)–H(5) C(2)–Ge–Cl(7) C(2)–Ge–Cl(8) Cl(7)–Ge–Cl(8)

θh1 [deg] a

Ge Cl Cl

120.4(5) 121.7(15) 121.2 d 122.5 d 111.0(2) 111.0 e 109.4(5)

Dihedral angle τh1 [deg] C(3)=C(2)–Ge–Cl(7) 0.0 f Reprinted with permission. Copyright 2010 American Chemical Society.

a Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2σ and a systematic error of 0.001r. b Difference to the C(2)–H(6) bond length was assumed at the value from B3LYP/cc-pVTZ computation. c Difference to the Ge–Cl(7) bond length was assumed at the value from computation as indicated above. d Difference to the C(3)=C(2)–H(6) bond angle was assumed at the value from computation as above. e Difference to the C(2)–Ge–Cl(8) bond angle was assumed at the value from computation as above. f Assumed.

The GED experiment was carried out at Tnozzle = 427 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Samdal S, Guillemin J-C, Gundersen S (2010) Molecular structure of trichloroethenylgermane, CH2=CH-GeCl3, as studied by gas-phase electron diffraction. Experimental determination of the barrier of internal rotation of the trichlorogermyl group supplemented with quantum chemical calculations on CH2=CH-MX3 (M = C, Si, Ge, Sn, and X = H, Cl). J Phys Chem A 114 (21):6331-6335

311 CAS RN: 1389355-30-9 MGD RN: 350152 MW augmented by ab initio calculations

Difluoroisocyanatosilane C2H3F2NOSi Cs

244

4 Molecules with Two Carbon Atoms

Bonds C(2)–Si Si–N N=C(1) C(1)=O Si–F C(2)–H

r0 [Å] a 1.814(5) 1.667(21) 1.205(25) 1.152(5) 1.57646(8) 1.092 b

rs [Å] a 1.849(1) 1.631(3) 1.231(2) 1.158(2)

Bond angles C(2)–Si–N Si–N=C(1)

θ0 [deg] a

θs [deg] a

177.2 b 108.4 b

179(24)

τ0 [deg] a

τs [deg] a

H(2)–C(2)–Si N=C(1)=O F–Si–N Dihedral angles F–Si–N=C(1) C(2)–Si–N=C(1) Si–N=C(1)=O H(1)–C(2)–Si–N

111.7(3) 159.8(9) 110.8 b

b

57.6 180.0 b 180.0 b 59.8 b

F

F

O C

Si

H 3C

N

110.8(2) 162(1)

180(40)

Reprinted with permission. Copyright 2012 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed at the value from CCSD(T)/6-311++G(3df,3pd) calculation.

The rotational spectrum of difluoroisocyanatosilane was recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the frequency region between 6.5 and 18 GHz. Only one conformer was observed. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, two 13C, 15N, 18O, 29Si and 30Si). The rs structure was obtained for the heavy-atom skeleton. Guirgis GA, Overby JS, Palmer MH, Peebles RA, Peebles SA, Elmuti LF, Obenchain DA, Pate BH, Seifert NA (2012) Molecular structure of methyldifluoroisocyanatosilane: A combined microwave spectral and theoretical study. J Phys Chem A 116(30):7822-7829

312 CAS RN: 1196682-76-4 MGD RN: 211730 MW

Distances Rcm b H(1)…F(2) H(2)…F(1)

r0 [Å] a 3.556654(90) 2.639(15) 2.528(40)

Angles

θ0 [deg] a

c

ϕ1 ϕ2 d

C–F(1)…H(2)

73.62(38) 78.9(26) 127.43(54)

1,1-Difluoroethene – hydrogen fluoride (1/1) 1,1-Difluoroethylene – hydrogen fluoride (1/1) C2H3F3 Cs H

F

H

F

H

F

4 Molecules with Two Carbon Atoms

F(2)–H(2)…F(1)

245

78.2(28)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Distance between centers of mass of the monomer subunits. c Angle between Rcm and the C=C bond. d Angle between Rcm and the H–F bond. b

The rotational spectra of the binary complex of 1,1-difluoroethylene with hydrogen fluoride were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 7 and 21 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, two 13C, D and 13C/D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Leung HO, Marshall MD, Drake TL, Pudlik T, Savji N, McCune DW (2009) Fourier transform microwave spectroscopy and molecular structure of the 1,1-difluoroethylene-hydrogen fluoride complex. J Chem Phys 131(20):204301/1-204301/8 doi:10.1063/1.3250865

313 CAS RN: 936855-50-4 MGD RN: 209457 MW supported by ab initio calculations

(1E)-1,2-Difluoroethene – hydrogen fluoride (1/1) trans-1,2-Difluoroethylene – hydrogen fluoride (1/1) C2H3F3 Cs H

F H

Distances H(1)…F(2) H(2)…F(1)

r0 [Å] a 2.6095(11) 1.9063(22)

Angles C–F(1)…H(2) F(2)–H(2)…F(1)

θ0 [deg] a

F

F

H

118.385(37) 158.64 b

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Constrained to average value of the main and deuterated species.

The rotational spectra of the binary complex of trans-1,2-difluoroethylene with hydrogen fluoride were recorded by a pulsed-jet FTMW spectrometer in the region between 6.5 and 22 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, two 13C, D and two 13C/D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Leung HO, Marshall MD, Amberger BK (2009) Fourier transform microwave spectroscopy and molecular structure of the trans-1,2-difluoroethylene-hydrogen fluoride complex. J Chem Phys 131(20):204302/1204302/8 doi:10.1063/1.3246841

246

4 Molecules with Two Carbon Atoms

314 CAS RN: 75-89-8 MGD RN: 648779 MW augmented by ab initio calculations

2,2,2-Trifluoroethanol C2H3F3O C1 (gauche) F OH

F

Bonds C(1)–C(2) C(1)–O(3) O(3)–H(4) C(1)–H(3) C(1)–H(2) C(2)–F(4) C(2)–F(5) C(2)–F(6)

r0 [Å]a 1.513(5) 1.406(5) 0.962(2) 1.089(2) 1.095(2) 1.348(5) 1.336(5) 1.343(5)

Bond angles C(1)–O(3)–H(4) C(2)–C(1)–O(3) F(4)–C(2)–C(1) F(5)–C(2)–C(1) F(6)–C(2)–C(1)

θ0 [deg]a

Dihedral angles F(4)–C(2)–C(1)–O(3) F(5)–C(2)–C(1)–O(3) F(6)–C(2)–C(1)–O(3) C(2)–C(1)–O(3)–H(4)

τ0 [deg]a

F

107.8(5) 112.4(5) 110.6(5) 112.7(5) 110.6(5)

59.2(5) -60.7(5) 178.3(5) 63.6(5)

Reproduced with permission of SNCSC

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters of the gauche conformer, characterized by the synclinal H–O–C–C torsional angle, was redetermined by adjusting the MP2_full/6-311+G(d,p) structure to the previously published ground-state rotational constants of two isotopic species. Durig JR, Ganguly A, Guirgis GA, Bell S, Mohamed TA, Gounev TK (2009) Conformational stability, r0 structural parameters, barriers to internal rotation, ab initio calculations, and vibrational assignment for 2,2difluoroethanol. Struct Chem 20(3):489-503

315 CAS RN; 624-83-9 MGD RN: 380562 MW augmented by ab initio calculations

Bonds C(1)–N N=C(2) C(2)=O C(1)–H(1)

Isocyanatomethane Methyl isocyanate C2H3NO Cs N a

r0 [Å] 1.447(3) 1.215(3) 1.116(3) 1.089(2)

H 3C

C O

4 Molecules with Two Carbon Atoms

C(1)–H(2)

1.093(2)

Bond angles N=C(2)=O C(1)–N=C(2) H(1)–C(1)–N H(2)–C(1)–N

θ0 [deg] a

247

172.6(5) 135.8(5) 108.6(5) 110.8(5)

Copyright 2008 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure of the title molecule was determined by fitting the MP2/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of one isotopic species. The evidence of nearly free rotation of the methyl group was indicated in the IR vibrational spectra. Zhou SX, Durig JR (2009) The r0 structural parameters, vibrational spectra, ab initio calculations and barriers to internal rotation and linearity of methyl isocyanate. J Mol Struct 924-926:111-119 316 CAS RN: 34627-31-1 MGD RN: 647039 GED augmented by ab initio computations

Bonds P–C P–H C≡C C–H

rh1 [Å] a 1.785(1) 1.424(4) 1.219(2) 1.057(7)

Bond angles H–P–H C–P–H P–C–C C≡C–H

θh1 [deg] a

Dihedral angle H–P–C≡C

τh1 [deg] a

Ethynylphosphine C2H3P Cs H

C

C

PH2

94.0(10) b 96.4(6) 175.5(23) 178.0((19) c

±132.6(5)

Reprinted with permission. Copyright 2009 American Chemical Society [a].

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Dependent parameter. c Restrained to the value from computation at the level of theory as indicated below. b

Molecular structure from Ref. [b] was reinvestigated. QC computations predicted the existence of only one conformer with Cs point-group symmetry (see also Ref. [b]).

248

4 Molecules with Two Carbon Atoms

The GED experiment was carried out at the temperatures of 205 and 215 K at the long and short nozzle-to-plate distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/6-311++G** computations. a. Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612 b. Cohen E, McRae GA, Goldwhite H, Di Stefano S, Beaudet RA (1987) Rotational spectrum, structure, and dipole moment of ethynylphosphine, H2PC≡CH Inorg Chem 26 : 4000-4003.

Chloro(η2-ethene)silver Ethene – silver chloride (1/1) C2H4AgCl C2v

317 CAS RN: 875585-23-2 MGD RN: 213286 MW augmented by ab initio calculations

Distances Ag–Cl rb C=C C–H

r0 [Å] a 2.2724(8) 2.1719(9) 1.3518(4) 1.0853 c

Angles C=C–H Ag…C=C–H

θ0 [deg] a

H 2C

rs [Å] a 2.2701(2) 2.1697(4) 1.354(40)

Ag

Cl

H2C

123.02(6) 94.51 c

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Distance between Ag and the midpoint of the C=C bond. c Adopted from computation at the CCSD(T) level of theory with the basis sets cc-pVQZ for C and H, ccpV(Q+d)Z for Cl and cc-pVQZ-PP for Ag. b

The rotational spectra of the binary complex of silver chloride with ethene were recorded in a pulsed-jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 9 and 16 GHz. The complex was produced in the gas phase by a reaction of tetrachloromethane and ethene with laser-ablated silver. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 109 Ag, 37Cl, 13C2, 109Ag/37Cl and 109Ag/13C2). The rs structure of the heavy-atom skeleton was also determined. Stephens SL, Tew DP, Mikhailov VA, Walker NR, Legon AC (2011) A prototype transition-metal olefin complex C2H4⋅⋅⋅AgCl synthesized by laser ablation and characterized by rotational spectroscopy and ab initio methods. J Chem Phys 135(2):024315/1-024315/10 doi:10.1063/1.3604821

318 CAS RN: 69030-43-9 MGD RN: 324459 MW augmented by ab initio calculations

Chloro(η2-ethene)copper Ethene – copper(I) chloride (1/1) C2H4ClCu C2v H2C H2C

Cu

Cl

4 Molecules with Two Carbon Atoms

249

r0 [Å] a 2.070(6) 1.908(7) 1.367(3) 1.088 c

rs [Å] a 2.064(8) 1.908(12)

Angle X…C–H b

θ0 [deg] a

θs [deg] a

Dihedral angle H–C–C–Cu

τ0 [deg] a 96.05 c

τs [deg] a

Distances Cu–Cl Cu…X b C=C C–H

122.5(5)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. X is the midpoint of the double C=C bond. c Assumed at the CCSD(T)/aug-cc-pVTZ(F12*) value corrected for the difference between the experimentally measured r0 and re distances in ethene. b

The rotational spectra of the binary complex of copper(I) chloride with ethene were recorded in a supersonic jet both by a chirped-pulse and a Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The r0 and rs structures were determined from the ground-state rotational constants of six isotopic species (main, 37 Cl, 13C2, 65Cu, 65Cu/37Cl and 65Cu/13C2). The complex was found to have a T-shaped structure in which the Cu atom is bound to the π-electrons of ethene. Stephens SL, Bittner DM, Mikhailov VA, Mizukami W, Tew DP, Walker NR, Legon AC (2014) Changes in the geometries of C2H2 and C2H4 on coordination to CuCl revealed by broadband rotational spectroscopy and abinitio calculations. Inorg Chem 53(19):10722-10730

319 CAS RN: MGD RN: 354452 MW supported by ab initio calculations

Chloroethene – hydrogen fluoride (1/1) Vinyl chloride – hydrogen fluoride (1/1) C2H4ClF Cs H

Cl

H

Distances Cl…F F…H

r0 [Å] a 2.319(6) 2.59(1)

Angle C–Cl…H

θ0 [deg] a

H

F

H

102.4(2)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the binary complex of vinyl chloride with hydrogen fluoride was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6.3 and 21.4 GHz.

250

4 Molecules with Two Carbon Atoms

The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Leung HO, Marshall MD (2014) Effect of acid identity on the geometry of intermolecular complexes: the microwave spectrum and molecular structure of vinyl chloride-HF. J Phys Chem A 118(41):9783-9790

320 CAS RN: MGD RN: 390924 MW augmented by ab initio calculations

Chlorofluoromethane – formaldehyde (1/1) C2H4ClFO Cs H

Distances Cl(2)…O(6) Cl(2)…H(8) H(4)…O(6) Rcm c C(1)–Cl(2) C(1)–F(3) C(1)–H(4) C(1)–H(5) C(7)=O(6) C(7)–H(8) C(7)–H(9)

r0 [Å] a 3.554(8) 2.918 b 2.821 b 3.700 1.770 d 1.370 d 1.086 d 1.086 d 1.215 d 1.104 d 1.104 d

Angles F(3)–C(1)–Cl(2) H(4)–C(1)–F(3) H(5)–C(1)–F(3) H(8)–C(7)=O(6) H(9)–C(7)=O(6) O(6)…Cl(2)–C(1) C(7)–O(6)…Cl(2) Cl(2)…H(8)–C(7) C(1)–H(4)…O(6) C(1)–Cl(2)…H(8)

θ0 [deg] a

Dihedral angles H(4)–C(1)–F(3)–Cl(2) H(5)–C(1)–F(3)–H(4) O(6)…Cl(2)–C(1)–F(3) C(7)=O(6)…Cl(2)–C(1) H(8)–C(7)=O(6)…C(1) H(9)–C(7)=O(6)–H(8)

109.7 d 109.0 d 109.0 d 121.6 d 121.6 d 61.9(2) 83(1) 120.8 b 96.6 b 96.7 b

τ0 [deg] a 118.7 d 122.6 d 180.0 d 180.0 d 0.0 d 180.0 d

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c Distance between the centers of mass of the monomer subunits. d MP2/6-311++G(d,p) value. b

Cl

O

H

F

H

H

4 Molecules with Two Carbon Atoms

251

The rotational spectrum of the binary complex of chlorofluoromethane with formaldehyde was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl); the remaining structural parameters were constrained to MP2/6-311++G(d,p) values. Feng G, Gou Q, Evangelisti L, Vallejo-López M, Lesarri A, Cocinero EJ, Caminati W (2014) Competition between weak hydrogen bonds: C-H⋅⋅⋅Cl is preferred to C-H⋅⋅⋅F in CH2ClF-H2CO, as revealed by rotational spectroscopy. Phys Chem Chem Phys 16(24):12261-12265

321 CAS RN: MGD RN: 414778 MW augmented by ab initio calculations

Dichloromethane – difluoromethane (1/1) C2H4Cl2F2 Cs H

Distances C(4)…C(2) F(2)…H(3) Cl(5)…H(6)

r0 [Å] a 3.755(1) 2.489(2) b 3.147(2) b

Angles H(3)–C(4)…C(1) F(2)–C(1)…C(4)

θ0 [deg] a

Dihedral angle

τ0 [deg] a 11.8(1) b

α

c

H

H

F

Cl

Cl

H

F

62.5(1) 55.7(1)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c Angle between the bisector of the Cl–C–Cl angle and the bc principle inertial plane. b

The rotational spectrum of the complex was recorded by a pulsed-jet Balle-Flygare-type FTMW spectrometer in the frequency range between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl); the remaining structural parameters were fixed to the MP2/6-311++G(d,p) values. The complex is formed by a network of two C–H….Cl–C and one C–H…F–C weak hydrogen bonds. Gou Q, Spada L, Vallejo-López M, Kisiel Z, Caminati W (2014) Interactions between freons: a rotational study of CH2F2-CH2Cl2. Chem Asian J 9(4):1032-1038

322 CAS RN: 1644412-33-8 MGD RN: 408250 MW supported by ab initio calculations

Fluoroisocyanatomethylsilane C2H4FNOSi C1 F O C

SiH H 3C

N

252

4 Molecules with Two Carbon Atoms

Bonds C–Si Si–N N=C

rs [Å] a 1.8427(70) 1.7086(77) 1.2120(90)

Bond angles C–Si–N Si–N=C

θs [deg] a

109.71(52) 157.69(18)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of fluoroisocyanatosilane was recorded in a pulsed supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial rs structure of the heavy-atom skeleton (except for the F atom) was determined from the ground-state rotational constants of six isotopic species (main, 29Si, 30Si, two 13C and 15N). Guirgis GA, Overby JS, Barker TJ, Palmer MH, Pate BH, Seifert NA (2015) The molecular structure of methylfluoroisocyanatosilane: a combined microwave spectral and theoretical study. J Phys Chem A 119(4):652658

323 CAS RN: 359-13-7 MGD RN: 931585 MW augmented by ab initio calculations

2,2-Difluoroethanol C2H4F2O C1 (gauche-gauche) F OH

Bonds C(1)–C(2) C(1)–O(3) C(2)–F(5) C(2)–F(4) C(2)–H(1) C(1)–H(2) C(1)–H(3) O(3)–H(4)

r0 [Å]a 1.510(3) 1.412(3) 1.362(3) 1.371(3) 1.090(2) 1.096(2) 1.091(2) 0.961(3)

Bond angles O(3)–C(1)–C(2) F(5)–C(2)–C(1) F(4)–C(2)–C(1) H(1)–C(2)–C(1) H(2)–C(1)–C(2) H(3)–C(1)–C(2) H(4)–O(3)–C(1)

θ0 [deg]a

Dihedral angles H(4)–O(3)–C(1)–C(2) F(4)–C(2)–C(1)–O(3) F(5)–C(2)–C(1)-O(3)

τ0 [deg]a

111.0(5) 109.8(5) 108.8(5) 113.8(5) 108.0(5) 108.9(5) 107.1(5) 64.3(5) 63.5(5) 179.1(5)

F

4 Molecules with Two Carbon Atoms

253

Reproduced with permission of SNCSC

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters of the gauche-gauche conformer, characterized by the synclinal F(4)–C–C–O and H–O–C–C torsional angles, was obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published ground-state rotational constants of two isotopic species. Durig JR, Ganguly A, Guirgis GA, Bell S, Mohamed TA, Gounev TK (2009) Conformational stability, r0 structural parameters, barriers to internal rotation, ab initio calculations, and vibrational assignment for 2,2difluoroethanol. Struct Chem 20(3):489-503

324 CAS RN: MGD RN: 378357 MW supported by ab initio calculations

Difluoromethane – formaldehyde (1/1) C2H4F2O Cs

Distances H(8)…F(2) O…F(2)

r0 [Å] a 2.658(1) 3.132(1) b

Angles C(7)–H(8)…F(2) H(8)…F(2)–C(1) O…F(2)–C(1) C(7)=O…F(2)

θ0 [deg] a

O

H

H

F

F

H

H

113.6(1) 113.4(1) 73.6(1) b 85.0(1) b

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the binary complex of difluoromethane with formaldehyde was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main and two 13C) under the assumption that the structural parameters were not changed upon complexation. Gou Q, Feng G, Evangelisti L, Vallejo-López M, Lesarri A, Cocinero EJ, Caminati W (2013) Non-bonding interactions and internal dynamics in CH2F2⋅⋅⋅H2CO: a rotational and model calculations study. Phys Chem Chem Phys 15(18):6714-6718

325 CAS RN: 753-90-2 MGD RN: 827733 MW augmented by QC calculations

2,2,2-Trifluoroethanamine 2,2,2-Trifluoroethylamine C2H4F3N Cs F F F

Distances

r0 [Å] a

NH2

254

4 Molecules with Two Carbon Atoms

C(1)–C(2) C(2)–N(3) C(1)–F(4) C(1)–F(5) C(1)–F(6) C(2)–H(1) C(2)–H(2) N(3)–H(3) N(3)–H(4) H(3)...F(5)

1.513(3) 1.447(3) 1.344(3) 1.347(3) 1.347(3) 1.092(2) 1.092(2) 1.013(3) 1.013(3) 2.655(5)

Bond angles C(1)–C(2)–N(3) F(4)–C(1)–C(2) F(5)–C(1)–C(2) F(6)–C(1)–C(2) F(4)–C(1)–F(6) F(4)–C(1)–F(5) F(5)–C(1)–F(6) H(1)–C(2)–H(2) H(1)–C(2)–C(1) H(2)–C(2)–C(1) H(1)–C(2)–N(3) H(2)–C(2)–N(3) H(3)–N(3)–H(4) H(3)–N(3)–C(2) H(4)–N(3)–C(2)

θ0 [deg] a

Dihedral angles F(4)–C(1)–C(2)–N(3) F(4)–C(1)–C(2)–H C(1)–C(2)–N(3)–H

τ0 [deg] a

115.2(5) 111.4(5) 111.6(5) 111.6(5) 107.6(5) 107.6(5) 106.9(5) 107.9(5) 107.0(5) 107.0(5) 109.7(5) 109.7(5) 108.0(5) 111.0(5) 111.0(5)

180 57.7(5) 60.1(5)

Copyright 2012 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The anti and gauche conformers, differing in the orientation of the amino group, were identified in the temperature-dependent Raman vibrational spectra. The percentage of the gauche conformer was estimated to be 35(3) % at ambient temperature. The r0 structural parameters of the anti conformer were determined by fitting the MP2_full/6-311+G(d,p) structure to the previously published ground-state rotational constants of two isotopic species. Durig JR, Darkhalil ID, Klaassen JJ, Nagels N, Herrebout WA, van der Veken BJ (2013) Conformational and structural studies of 2,2,2-trifluoroethylamine from temperature dependent Raman spectra of xenon solutions and ab initio calculations. J Mol Struct 1032:229-239

326 CAS RN: MGD RN: 411790 MW supported by ab initio calculations

Oxirane – dinitrogen (1/1) Ethylene oxide – dinitrogen (1/1) C2H4N2O Cs O

N

N

4 Molecules with Two Carbon Atoms

Distances Rcm b N≡N

r0 [Å] a 3.596

rs [Å] a 1.0970

θs [deg] a

Angle

α

255

c

56.21

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Uncertainties were not given in the original paper. Distance between the centers of mass of the monomer subunits. c Angle between N≡N and the a axis of the complex. b

The rotational spectrum of the binary van der Waals complex of oxirane with dinitrogen was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 27 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, two 15N and 15N2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Kawashima Y, Hirota E (2013) Fourier transform microwave spectrum of the nitrogen molecule-ethylene oxide complex: intracomplex motions. J Phys Chem A 117(50):13855-13867

327 CAS RN: 557-75-5 MGD RN: 103640 MW augmented by ab initio calculations

Ethenol Vinyl alcohol C2H4O Cs (syn)

Bonds C(1)–O O–H C(1)–H(2) C(1)=C(2) C(2)–H(4) C(2)–H(3)

r e [Å] a 1.3594(8) 0.9604(2) 1.0794(4) 1.3312(9) 1.0816(2) 1.0772(4)

Bond angles C(1)–O–H O–C(1)–H(2) O–C(1)=C(2) C(2)=C(1)–H(2) C(1)=C(2)–H(4) C(1)=C(2)–H(3) H(3)–C(2)–H(4)

θ see [deg] a

se

H

OH

H

H

108.81(4) 111.06(32) 126.297(5) 122.65(32) 121.90(4) 119.59(2) 118.51(3)

Copyright 2014 Wiley Periodicals. Inc. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure of the syn conformer characterized by the synperiplanar H–O– C(1)=C(2) dihedral angle was determined from the previously published ground-state rotational constants of

256

4 Molecules with Two Carbon Atoms

nine isotopic species accounting for rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVQZ quadratic and cubic force fields. Vogt N, Demaison J, Vogt J, Rudolph HD (2014) Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method: structure of molecules containing the OH or the CH3 group. J Comput Chem 35(32):2333-2342

328 CAS RN: 75-21-8 MGD RN: 601340 MW augmented by ab initio calculations

Oxirane Ethylene oxide C2H4O C2v O

Bonds C–C C–O C–H Bond angle H–C–H

r e [Å] a 1.46082(2) 1.42726(2) 1.08209(2) se

θ see [deg] a

116.189(3)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. se

The semiexperimental equilibrium structure r e of oxirane was determined from the previously published experimental ground-state rotational constants of eleven isotopic species taking into account rovibrational corrections calculated with the MP2/cc-pVTZ quadratic and cubic force fields. Demaison J, Császár AG, Margulès LD, Rudolph HD (2011) Equilibrium structures of heterocyclic molecules with large principal axis rotations upon isotopic substitution. J Phys Chem A 115(48):14078-14091

329 CAS RN: 64-19-7 MGD RN: 455773 GED augmented by ab initio computations

Acetic acid C 2H 4O 2 Cs O

Bonds C=O C–O C–C O–H C–H

rh1 [Å] a 1.196(4) b 1.365(6) 1.500(3) b 0.969(3) b 1.086(8) b,c

Bond angles H(1)–C–H(2) C–C–H

θh1 [deg] a 110.5(2) 109.5(2) b

H 3C

OH

4 Molecules with Two Carbon Atoms

C–C=O C–C–O C–O–H

126.4(6) b 110.4(7) b 105.7(27) b

Dihedral angle H–O–C–C

τh1 [deg]

257

180.0 d

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Constrained to the value from MP2/6-311++G** computation. c Average value. d Assumed. b

The GED experiment for the pyrolysis products of acetic anhydride, namely ketene and acetic acid, was carried out with a maintained temperature of 823 K. It was assumed that ketene and acetic acid were generated in the ratio of 67 : 33 (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from MP2/6-311++G** computation. Atkinson SJ, Noble-Eddy R, Masters SL (2016) Gas-phase structures of ketene and acetic acid from acetic anhydride using very-high-temperature gas electron diffraction. J Phys Chem A 120 (12):2041-2048

330 CAS RN: 107-31-3 MGD RN: 692601 MW augmented by ab initio calculations

Bonds

Formic acid methyl ester Methyl formate C 2H 4O 2 Cs O

se e

a

C(2)–O(2) O(2)–C(1) C(2)–H(1) C(2)–H(2) C(1)–H C(1)=O(1)

r [Å] 1.4341(5) 1.3345(4) 1.0793(10) 1.0871(3) 1.0930(5) 1.2005(5)

Bond angles

θ see [deg] a

C(1)–O(2)–C(2) O(2)–C(2)–H(1) O(2)–C(2)–H(2) H–C(1)–O(2) O(1)=C(1)–O(2) Dihedral angle C(1)–O(2)–C(2)–H(2)

114.32(4) 106.05(16) 110.19(2) 109.60(5) 125.50(5)

τ see [deg] a -60.28(3)

Copyright 2009 with permission from Elsevier.

H

O

CH3

258 a

4 Molecules with Two Carbon Atoms

Uncertainties in parentheses in units of the last significant digit.

The semiexperimental equilibrium structure of the syn conformer was obtained from the previously published experimental ground-state rotational constants of eleven isotopic species by taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Demaison J, Margulès L, Kleiner I, Császár AG (2010) Equilibrium structure in the presence of internal rotation: A case study of cis-methyl formate. J Mol Spectrosc 259(2):70-79

331 CAS RN: 141-46-8 MGD RN: 916188 MW supported by DFT calculations

2-Hydroxyacetaldehyde Glycolaldehyde C 2H 4O 2 Cs O

HO a

Bonds C(1)–O(1) C(2)=O(2) C(1)–C(2) O(1)–H(1) C(2)–H C(1)–H H(1)...O(2) O(1)...O(2)

rs [Å] 1.3996(32) 1.2102(36) 1.5012(29) 1.0554(29) 1.1038(27) 1.1030(20) 2.0011(30) 2.6851(15)

Angles C(1)–C(2)=O(2) C(1)–C(2)–H C(2)–C(1)–O(1) C(1)–O(1)–H C(2)–C(1)–H H–C(1)–H H–C(1)–O(1) O(1)–H(1)…O(2) H(1)…O(2)–C(2)

θs [deg] a

H

121.90(43) 115.97(35) 112.28(31) 102.35(32) 108.37(29) 106.18(28) 110.69(34) 119.67(33) 83.78(23)

Copyright 2013 with permission from Elsevier [a].

a

Parenthesized uncertainties are Costain errors in units of the last significant digit.

The rotational spectrum of glycolaldehyde was recorded by two pulsed-jet chirped-pulse FTMW spectrometers in the frequency region between 6.5 and 40 GHz. The rs structure was determined from the ground-state rotational constants of 13C and 18O species together with rotational constants for the main and deuterated species taken from the literature. a. Carroll PB, McGuire BA, Zaleski DP, Neill JL, Pate BH, Widicus Weaver SL (2013) The pure rotational spectrum of glycolaldehyde isotopologues observed in natural abundance. J Mol Spectrosc 284-285:21-28 MW augmented by ab initio calculations

Cs

4 Molecules with Two Carbon Atoms

Bonds C(2)=O(2) C(2)–H C(1)–C(2) C(1)–H C(1)–O(1) O(1)–H

r see [Å] a 1.2092(4) 1.1009(4) 1.5005(3) 1.0972(2) 1.3956(4) 0.9650(11) b

Bond angles C(1)–C(2)=O(2) C(1)–C(2)–H C(2)–C(1)–H C(2)–C(1)–O(1) C(1)–O(1)–H

θ see [deg] a

Dihedral angle H–C(1)–C(2)=O(2)

τ see [deg] a 122.40(3)

259

116.82(8) 126.04(8) 108.07(3) 111.80(3) 105.97(7) b

Copyright 2014 Wiley Periodicals, Inc. Reproduced with permission [b].

a b

Parenthesized uncertainties in units of the last significant digit. Constrained to the previously published value of CCSD(T)_ae/cc-pCV5Z quality.

The semiexperimental equilibrium structure was determined from the previously published experimental groundstate rotational constants of nine isotopic species accounting for rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. b. Vogt N, Demaison J, Vogt J, Rudolph HD (2014) Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method: structure of molecules containing the OH or the CH3 group. J Comput Chem 35(32):2333-2342

332 CAS RN: 289-14-5 MGD RN: 531135 MW augmented by DFT calculations

1,2,4-Trioxolane Ethylene ozonide C 2H 4O 3 C2 O

Bonds C–O(1) C–H(x) b C–H(q) c C–O(2) O(2)–O(2ꞌ)

r e [Å] a 1.4135(3) 1.0907(5) 1.0859(5) 1.4080(3) 1.4577(3)

Bond angles C–O(1)–C H(x)–C–O(1) b H(q)–C–O(1) c

θ see [deg] a

se

104.51(3) 109.88(5) 110.90(4)

O

O

260

4 Molecules with Two Carbon Atoms

O(1)–C–O(2)

105.53(2)

Dihedral angles H(x)–C–O(1)–C b H(q)–C–O(1)–C c O(2)–C–O(1)–C

τ see [deg] a

102.90(6) -131.94(5) -16.454(7)

Reprinted with permission. Copyright 2011 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit. H(x) is an axial H atom. c H(q) is an equatorial H atom. b

se

The semiexperimental equilibrium structure r e of ethylene ozonide was determined from the previously published experimental ground-state rotational constants of twenty isotopic species taking into account vibrational corrections calculated with the B3LYP/6-311+G(3df,2pd) harmonic and anharmonic (cubic) force fields. Demaison J, Császár AG, Margulès LD, Rudolph HD (2011) Equilibrium structures of heterocyclic molecules with large principal axis rotations upon isotopic substitution. J Phys Chem A 115(48):14078-14091

333 CAS RN: MGD RN: 427910 MW supported by ab initio calculations

Formic acid - formaldehyde (1/1) C 2H 4O 3 Cs O

Distances C(1)..C(6) C(1)–H(4) H(5)…O(7)

r0 [Å] a 3.7388(7) 1.108(9) 1.745(1) b

Angles H(4)–C(1)–O(3) C(6)…C(1)=O(2) C(1)…C(6)=O(7)

θ0 [deg] a

rs [Å] a 3.708(14) 1.101(1)

H

O

OH

H

H

109.5(8) 57.07(4) 64.18(5)

Reprinted with permission. Copyright 2014 American Chemical Society. a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the binary complex of formic acid with formaldehyde was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, two 13C and two D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The partial rs structure was also obtained. Formic acid and formaldehyde units are linked together through the strong OH…O and weak CH…O= hydrogen bonds. The complex appeared to be quite rigid; no effects of the internal motions were observed in the spectrum. Gou Q, Favero LB, Bahamyirou SS, Xia Z, Caminati W (2014) Interactions between carboxylic acids and aldehydes: a rotational study of HCOOH-CH2O. J Phys Chem A 118(45):10738-10741

4 Molecules with Two Carbon Atoms

334 CAS RN: 21511-46-6 MGD RN: 517233 GED augmented by QC computations

Bonds C–S C–H S=O

rh1 [Å] a 1.819(1) 1.083(2) b 1.430(1)

Angles C–S–C S…X…S c X…C–H c H–C–H O=S=O

θh1 [Å] a

261

1,3-Dithietane 1,1,3,3-tetraoxide 1,3-Dithiacyclobutane 1,1,3,3-tetraoxide C2H4O4S2 D2h (see comment)

87.2(1) b 180.0 d 122.7 d 115.0(1) b 121.3(1) b

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Restrained to the value from MP2_full/aug-cc-pVTZ computation. c X is the midpoint between the carbon atoms. d Assumed at the value from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle of 483 and 513 K at the long and short nozzle-to-film distances, respectively. Two molecular models with D2h and C2v symmetry, characterized by the planar and puckered (by up to 9°) rings, respectively, were used in the GED analysis. The structural parameters are presented for the slightly preferable model of D2h symmetry. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra− rh1, were calculated from the B3LYP/6-311++G(d,p) harmonic force constants. Wann DA, Bil A, Lane PD, Robertson HE, Rankin DWH, Block E (2013) Gas-phase structures of dithietane derivatives, including an electron diffraction study of 1,3-dithietane 1,1,3,3-tetraoxide. Struct Chem 24 (3):827835

335 CAS RN: 2308-54-5 MGD RN: 546241 MW

Distance C(1)…S

rs [Å] a 3.8944(3)

Reprinted with permission. Copyright 2017 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit.

Acetic acid anhydride with sulfuric acid Acetic sulfuric anhydride C2H4O5S C1 O

O

O

S H 3C

O

OH

262

4 Molecules with Two Carbon Atoms

The rotational spectrum of acetic sulfuric anhydride was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 18 GHz. The transient species was produced by a gas phase reaction of sulfur trioxide with acetic acid. The partial rs structure was determined from the ground-state rotational constants of two isotopic species (main and 34S). Huff AK, Mackenzie RB, Smith CJ, Leopold KR (2017) Facile formation of acetic sulfuric anhydride: Microwave spectrum, internal rotation, and theoretical calculations. J Phys Chem A 121(30):5659-5664

336 CAS RN: 78507-83-2 MGD RN: 137771 GED combined with MW and augmented by ab initio computations

Ethenylarsine Vinylarsine C2H5As Cs (I) C1 (II) H 2C

Bonds C–H As–H(1) C=C As–C

AsH2

rh1 [Å] a Cs (I) C1 (II) 1.100(4) b,c 1.100(4) b,c 1.505(4) 1.501(4) d 1.344(2) b 1.344(2) b 1.951(1) 1.949(1) d I

Bond angles C(1)=C(2)–H C(2)=C(1)–H C=C–As C=As–H(1) C=As–H(2) H–As–H Dihedral angles C=C–As–H(2) H(3)–C=C–As

θh1 [deg] a

Cs (I) 123.3(7) b,c 119.9(8) b,c 119.4(2) 95.5(8) c 93.3(6) c

C1 (II) 123.3(7) b,c 119.9(8) b,c 124.1(2) 95.2(9) c 96.4(9) c 91.1(8)

τh1 [deg] a

II

C1 (II) 65.3(18) c 5.8(10) c

Copyright 2009 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Assumed to be equal in both conformers. c Restrained to the value from MP2/6-311++G** computation. d Difference to that in conformer I was restrained to the value from computations as above. b

The GED experiment was carried out at the nozzle temperature of 293 K. The title compound was found to exist as a mixture of two conformers, I and II, with Cs and C1 overall symmetry, respectively, in the ratio Cs : C1 = 36(6) : 63(6) (in %) corresponding to an energy difference of 0.4(6) kJ mol-1. In the conformer I, the C–C–As–H torsional angles are ± anticlinal, whereas they are synperiplanar and synclinal in the conformer II. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, and experimental rotational constants, ∆Xh1 = X0– Xh1, where X = A, B, C, were calculated using the MP2/6-31+G* harmonic force constants.

4 Molecules with Two Carbon Atoms

263

Noble-Eddy R, Masters SL, Rankin DWH, Robertson HE, Guillemin JC (2010) Molecular structures of vinylarsine, vinyldichloroarsine and arsine studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 978 (1-3):26-34

337 CAS RN: 371-62-0 MGD RN: 871615 MW augmented by ab initio calculations

2-Fluoroethanol C2H5FO C1 (gauche-gauche) F

OH

Bonds C(1)–C(2) C(1)–O(3) O(3)–H(4) C(1)–H(6) C(1)–H(5) C(2)–H(8) C(2)–H(7) C(2)–F(4)

r0 [Å]a 1.510(5) 1.418(5) 0.962(2) 1.093(2) 1.092(2) 1.093(2) 1.097(2) 1.402(5)

Bond angles C(1)–O(3)–H(4) C(2)–C(1)–O(3) F(4)–C(2)–C(1)

θ0 [deg]a

Dihedral angles F(4)–C(2)–C(1)–O(3) C(2)–C(1)–O(3)–H(4)

τ0 [deg]a

107.6(5) 111.8(5) 107.6(5)

63.7(5) -57.4(5)

Reproduced with permission of SNCSC

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters of the gauche-gauche conformer, characterized by the synclinal F(4)–C–C–O and H–O–C–C torsional angles, was obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published ground-state rotational constants of two isotopic species. Durig JR, Ganguly A, Guirgis GA, Bell S, Mohamed TA, Gounev TK (2009) Conformational stability, r0 structural parameters, barriers to internal rotation, ab initio calculations, and vibrational assignment for 2,2difluoroethanol. Struct Chem 20(3):489-503

338 CAS RN: 1072849-40-1 MGD RN: 495802 MW augmented by ab initio calculations

2-Fluoroacetic acid – water (1/1), C2H5FO3 C1 O O F

Distances

anti r0 [Å] a

syn r0 [Å] a

H OH

H

264

4 Molecules with Two Carbon Atoms

O(9)…H(8) C(1)–C(2) C(2)–F(3) C(2)–H(4) C(2)–H(5) C(1)=O(6) C(1)–O(7) O(7)–H(8) O(9)–H(1) O(9)–H(2)

1.7651(2) 1.5169 b 1.3741 b 1.0931 b 1.0929 b 1.2128 b 1.3386 b 0.9839 b 0.9669 b 0.9600 b

1.7853(2) 1.5169 b 1.3772 b 1.0922 b 1.0930 b 1.2201 b 1.3250 b 0.9851 b 0.9669 b 0.9601 b

Angles O(9)…H(8)–O(7) C(1)–C(2)–F(3) C(1)–C(2)–H(4) H(4)–C(2)–H(5) C(2)–C(1)=O(6) O(7)–C(1)=O(6) C(1)–O(7)–H(8) H(8)…O(9)–H(1) H(1)–O(9)–H(2)

θ0 [deg] a

θ0 [deg] a

Dihedral angles H(4)–C(2)–C(1)–F(3) H(5)–C(2)–H(4)–C(1) O(6)=C(1)–C(2)–F(3) O(7)–C(1)=O(6)–C(2) O(9)…H(8)–O(7)–C(1) H(1)–O(9)…H(8)–O(7) H(2)–O(9)–H(1)…H(8)

τ0 [deg]

τ0 [deg]

158.87(1) 110.8 b 109.3 b 109.2 b 124.9 b 125.6 b 107.5 b 92.8 b 105.7 b

120.1 b -119.6 b 2.0 b -179.8 b 6.6 b -11.0 b 136.1 b

anti

158.45(1) 113.3 b 108.0 b 109.2 b 119.9 b 125.8 b 107.0 b 92.8 b 105.8 b syn

-121.2 b -117.1 b 175.4 b -179.2 b 7.0 b -11.2 b 135.4 b

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainty in units of the last significant digit. MP2/6-311++G(d,p) value.

The rotational spectra of the binary complex of fluoroacetic acid with water were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 8 and 18.5 GHz. Two conformers were observed. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 18 O, D2 and D3); the remaining structural parameters were constrained to the values from MP2/6-311++G(d,p) computation. Feng G, Gou Q, Evangelisti L, Spada L, Blanco S, Caminati W (2016) Hydrated forms of fluoroacetic acid: a rotational study. Phys Chem Chem Phys 18(34):23651-23656

339 CAS RN: 430-67-1 MGD RN: 771272 MW augmented by QC calculations

2,2-Difluoroethylamine C2H5F2N Cs (anti-anti) C1 (gauche-gauche) C1 (gauche-anti)

anti-anti

gauche-gauche

gauche-anti

4 Molecules with Two Carbon Atoms

265

Bonds C(1)–C(2) C(2)–N C(1)–F(4) C(1)–F(6) C(1)–H(5) C(2)–H(7) C(2)–H(8) N–H(9) N–H(3)

r0 [Å] a 1.514(3) 1.452(3) 1.368(3) 1.368(3) 1.092(2) 1.094(2) 1.094(2) 1.014(2) 1.014(2)

r0 [Å] a 1.507(3) 1.458(3) 1.370(3) 1.365(3) 1.090(2) 1.098(2) 1.092(2) 1.014(2) 1.013(2)

r0 [Å] a 1.512(3) 1.453(3) 1.369(3) 1.366(3) 1.093(2) 1.093(2) 1.093(2) 1.014(2) 1.014(2)

Bond angles N–C(2)–C(1) F(4)–C(1)–C(2) F(6)–C(1)–C(2) F(4)–C(1)–H(5) F(6)–C(1)–H(5) F(4)–C(1)–F(6) H(5)–C(1)–C(2) H(7)–C(2)–C(1) H(8)–C(2)–C(1) H(7)–C(2)–H(8) H(9)–N–C(2) H(3)–N–C(2) H(3)–N–H(9)

θ0 [deg] a

θ0 [deg] a

θ0 [deg] a

Dihedral angles F(4)–C(1)–C(2)–N F(6)–C(1)–C(2)–N H(9)–N–C(2)–C(1) H(3)–N–C(2)–C(1)

τ0 [deg] a

τ0 [deg] a

τ0 [deg] a

115.0(5) 110.3(5) 110.3(5) 107.7(5) 107.7(5) 106.5(5) 113.9(5) 107.6(5) 107.6(5) 107.5(5) 110.3(5) 110.3(5) 107.3(5)

58.6(5) -58.6(5) -59.2(5) 59.2(5)

108.8(5) 109.3(5) 110.0(5) 108.1(5) 108.5(5) 107.0(5) 113.5(5) 107.5(5) 107.6(5) 108.3(5) 110.3(5) 110.6(5) 107.5(5)

64.5(5) -178.1(5) -72.13(5) 169.0(5)b

F NH2 F

114.8(5) 109.5(5) 109.9(5) 107.4(5) 108.2(5) 107.1(5) 114.0(5) 107.2(5) 108.0(5) 107.7(5) 110.7(5) 111.4(5) 107.9(5)

61.2(5) 178.8(5) -56.6(5) 63.5(5)

Copyright 2010 with permission from Elsevier.

a b

Parenthesized estimated uncertainties in units of the last significant digit. Instead of 69.0(5) obviously misprinted in the original paper.

anti–anti

gauche-gauche

gauche-anti

Three conformers, anti-anti, gauche-gauche and gauche-anti, characterized by the antiperiplanar or synclinal N–C–C–H (first descriptor) and lp–N–C–C (second descriptor) torsional angles (lp is electron lone pair of the N atom), were identified by temperature-dependent IR vibrational spectroscopy. The amounts of the most stable anti-anti , the second most stable gauche-gauche and the minor gauche-anti conformers were estimated for ambient temperature to be 34(1), 45(1) and 22(1) %, respectively. The r0 structural parameters of each conformer were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of one isotopic species.

266

4 Molecules with Two Carbon Atoms

Durig JR, Klaassen JJ, Panikar SS, Darkhalil ID, Ganguly A, Guirgis GA (2011) Conformational and structural studies of 2,2-difluoroethylamine from temperature dependent infrared spectra of xenon solution and ab initio calculations. J Mol Struct 993(1-3):73-85

340 CAS RN: 56003-81-7 MGD RN: 752731 MW augmented by QC calculations

(E)-Ethanimine cis-Ethaneimine C 2H 5N Cs H

N

Bonds N–H C(2)=N C(1)–C(2) C(2)–H C(1)–H(2) C(1)–H(1)

r0 [Å] a 1.022(3) 1.276(3) 1.500(3) 1.098(2) 1.090(2) 1.094(2)

Bond angles H–N=C(2) N–C(2)–C(1) C(1)–C(2)–H C(2)–C(1)–H(2) C(2)–C(1)–H(1)

θ0 [deg] a

H 3C

H

109.4(5) 121.2(5) 116.2(5) 110.0(5) 110.3 (5)

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure of the title molecule was determined by adjusting the MP2_full/6-311+G(d) structure to the previously published ground-state rotational constants. Durig JR, Zhou SX, Zhou CX, Durig NE (2010) Structural parameters, vibrational spectra and centrifugal distortion constants of F(CN)C=NX (X = H, F, Cl, Br) and CH3(Y)C=NH (Y = H, CN). J Mol Struct 967(1-3):114

341 CAS RN: 20729-41-3 MGD RN: 152577 MW augmented by QC calculations

Bonds N–H C(2)=N C(1)–C(2) C(2)–H C(1)–H(2) C(1)–H(1)

(Z)-Ethanimine trans-Ethaneimine C 2H 5N Cs H

N

r0 [Å] a 1.025(3) 1.275(3) 1.508(3) 1.094(2) 1.093(2) 1.094(2)

H 3C

H

4 Molecules with Two Carbon Atoms

267

θ0 [deg] a

Bond angles H–N=C(2) N–C(2)–C(1) C(1)–C(2)–H C(2)–C(1)–H(2) C(2)–C(1)–H(1)

108.8(5) 127.2(5) 116.4(5) 111.2(5) 110.1 (5)

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure of the title molecule was determined by adjusting the MP2_full/6-311+G(d) structure to the previously published ground-state rotational constants. Durig JR, Zhou SX, Zhou CX, Durig NE (2010) Structural parameters, vibrational spectra and centrifugal distortion constants of F(CN)C=NX (X = H, F, Cl, Br) and CH3(Y)C=NH (Y = H, CN). J Mol Struct 967(1-3):114

342 CAS RN: 157-16-4 MGD RN: 153875 MW augmented by ab initio calculations Bonds C–N C–C N–H C–H(1) C–H(2) Bond angles H–N–C C–N–C N–C–C H–C–H N–C–H(1) N–C–H(2) C–C–H(1) C–C–H(2)

Aziridine Ethyleneimine C 2H 5N Cs

r m [Å] a 1.4698(7) 1.4771(9) 1.0133(4) 1.0821(3) 1.0810(3) ( 2)

θ (m2) [deg] a 109.38(3) 60.33(3) 59.84(2) 115.59(8) 118.34(7) 114.32(7) 117.80(4) 119.37(5)

N H

r e [Å] a 1.47013(6) 1.47703(8) 1.01279(13) 1.08099(13) 1.07971(13) se

θ see [deg] a

109.376(9) 60.311(6) 59.845(3) 115.424(9) 118.28(2) 114.46(2) 117.829(14) 119.538(14)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. ( 2)

The mass-dependent r m structure was determined from the previously published ground-state rotational se

constants of eight isotopic species. The semiexperimental equilibrium structure r e was obtained taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVQZ harmonic and anharmonic (cubic) force fields.

268

4 Molecules with Two Carbon Atoms

Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and sevenmembered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746

343 CAS RN: 51288-53-0 MGD RN: 113700 MW, IR supported by ab initio calculations

Ethyne – ammonia (1/1) Acetylene – ammonia (1/1) C 2H 5N C3v N

H

C

C

H

H

H

H

Distances H…N Rcm b

r0 [Å] a 2.3980(7) 4.0594(6)

Angle

θ0 [deg] a

α

c

23.29(2)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Distance between centers of mass in both monomer subunits. c Angular oscillation of ammonia subunit. b

The rotational spectra of the binary complex of acetylene with ammonia were recorded by a pulsed-nozzle FTMW spectrometer in the frequency region between 6.5 and 18 GHz and by a pulsed-nozzle multipass absorption spectrometer, based on a quantum cascade laser spectrometer, at about 1638 cm-1. The partial r0 structure was determined from the ground-state rotational constants under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Liu X, Xu Y (2011) Infrared and microwave spectra of the acetylene-ammonia and carbonyl sulfide-ammonia complexes: a comparative study of a weak C-H⋅⋅⋅N hydrogen bond and an S⋅⋅⋅N bond. Phys Chem Chem Phys 13(31):14235-14242

344 CAS RN: 123-39-7 MGD RN: 563471 MW supported by ab initio calculations

Bonds C(1)=O C(1)–N N–C(2) N–H

rs [Å] a 1.209(3) 1.353(1) 1.455(1) 1.019(5)

Bond angles O=C(1)–N C(1)–N–C(2) C(1)–N–H

θs [deg] a

125.0(4) 121.0(3) 122.4(10)

N-Methylformamide C2H5NO close to Cs O

H

N H

CH3

4 Molecules with Two Carbon Atoms

Dihedral angles O=C(1)–N–C(2) O=C(1)–N–H

269

τs [deg] a 2.2(5) 176.8(5)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded in a supersonic jet by FTMW and millimeter-wave absorption spectrometers in the spectral regions between 4 -43 and 58-118 GHz, respectively. Two conformers, anti and syn, with the antiperiplanar and synperiplanar O=C–N–H torsional angles, respectively, were identified. The partial rs structure was determined for the anti conformer from the groundstate rotational constants of six isotopic species (main, two 13C, 15N, 18O and D). Kawashima Y, Usami T, Suenram RD, Golubiatnikov GY, Hirota E (2010) Dynamical structure of peptide molecules: Fourier transform microwave spectroscopy and ab initio calculations of N-methylformamide. J Mol Spectrosc 263(1):11-20

345 CAS RN: 56955-04-5 MGD RN: 125575 MW

Acetonitrile – water (1/1) C2H5NO C3v H H

Distances Rcm b N…H N…O

r0 [Å] a 4.3385(12) 2.0747(11) 3.0307(7)

Angles N…H–O C≡N…H

θ0 [deg] a

C

N

O H

H

H

180 178.8

Copyright 2015 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the acetonitrile and water subunits.

The rotational spectrum of the binary complex of acetonitrile with water was recorded by a pulsed-beam FTMW spectrometer in the frequency region between 9 and 22 GHz. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, two 13C, 15N, 18O, D, D2 and 15N/D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation; the r0 structure of acetonitrile was refitted before. The CH3CN ‧ H2O complex exhibited a symmetric top spectrum for two tunneling components, whereby the H2O subunit tunnels between two equivalent forms. Lovas FJ, Sobhanadri J (2015) Microwave rotational spectral study of CH3CN-H2O and Ar-CH3CN. J Mol Spectrosc 307:59-64

346

Nitroethane

270

4 Molecules with Two Carbon Atoms

CAS RN: 79-24-3 MGD RN: 855690 GED supported by QC computations

C2H5NO2 Cs O H 3C

N O

a,b

Bonds C–C C–N C(2)–H(5) C(2)–H(3) C(1)–H(1) N=O(1) N=O(2)

rh1 [Å] 1.508(2) 1 1.514 1 1.094(5) 2 1.091 2 1.091 2 1.223(1) 3 1.224 3

Bond angles C–C–N C(1)–C(2)–H(5) C(1)–C(2)–H(3) C(2)–C(1)–H(1) C–N=O(1) C–N=O(2) O=N=O

θh1 [deg] a,b

Dihedral angle C–C–N=O(1)

τh1 [deg]

114.5(6) 108.7 c 111.4 c 113.1c 118.8(1) 4 116.2 4 125.0(2) d

0 or 90 e

Copyright 2009 with permission from Elsevier [a].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were constrained to the values from B3LYP/cc-pVTZ computation. c Adopted from computation as indicated above. d Dependent parameter. e See comment. b

Experimental data from Ref. [b] (Tnozzle = 325 K) were alternatively investigated using model of pseudoconformers. The difference values between the corresponding structural parameters of pseudo-conformers (relaxation effects) were fixed at the computed values. The large-amplitude torsion of the NO2 group around the N–C bond was described by a dynamic model with the following PEF: V(τ) = (1/2)V2(1 − cos 2τ) + (1/2)V4(1 − cos 4τ). The barrier to internal rotation, V2, was determined to be 0.61.1(3) kJ mol−1, and, thus, the rotation of the nitro group was characterized as being close to free. Because of the large uncertainties in the refined PEF constants, the reliable preference of the conformer with planar or orthogonal C−C−N=O fragment was not possible. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated from the B3LYP/6-31G* harmonic force field. Predictions of QC calculations concerning molecular structure of this molecule are ambiguous. According to result of B3LYP/cc-pVTZ calculation, the molecular skeleton is planar, whereas the orthogonal configuration corresponds to the minimum on PES from MP2/cc-pVTZ computation. a. Shishkov IF, Sipachev VA, Dem'yanov PI, Dorofeeva OV, Vogt N, Vishnevskiy YV, Vilkov LV (2010) An alternative gas-phase electron diffraction and quantum chemical study of nitroethane. J Mol Struct 978 (1-3):4147 b. Tarasov YI, Kochikov IV, Vogt N, Stepanova AV, Kovtun DM, Ivanov AA, Rykov AN, Deyanov RZ, Novosadov BK, Vogt J (2008) Electron diffraction and quantum chemical study of the structure and internal rotation in nitroethane. J Mol Struct 872:150-165.

4 Molecules with Two Carbon Atoms

271

347 CAS RN: 56-40-6 MGD RN: 346789 MW augmented by ab initio calculations

Aminoacetic acid Glycine C2H5NO2 Cs O

H 2N

Bonds C(2)–O(2) C(2)=O(1) O(2)–H C(1)–C(2) C(1)–N C(1)–H N–H

r e [Å] a 1.34827(31) 1.20331(62) 0.9645 b 1.51318(47) 1.44245(14) 1.09078(7) 1.01044(10)

Bond angles

θ see [deg] a

O(1)=C(2)–O(2) H–O(2)–C(2) C(1)–C(2)–O(2) N–C(1)–C(2) H–C(1)–C(2) H–N–C(1) Dihedral angles H–C(1)–C(2)=O(1) H–N–C(1)–C(2)

OH

se

122.991(31) 106.64 b 111.482(41) 115.285(17) 107.36 c 110.10 c

τ see [deg] 123.21 c 57.43 c

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Adopted from CCSD(T)/CBS calculations. c The value was not fitted directly. b

se

The semiexperimental equilibrium structure r e was determined from the previously published experimental ground-state rotational constants of the anti-anti-anti conformer taking into account rovibrational corrections calculated from the B3LYP/SNSD harmonic and anharmonic (cubic) force fields. Barone V, Biczysko M, Bloino J, Puzzarini C (2013) Glycine conformers: a never-ending story? Phys Chem Chem Phys 15(5):1358-1363 348 CAS RN: 22422-78-2 MGD RN: 214873 MW supported by ab initio calculations

Distances Rcm b

Formic acid – formamide (1/1) C2H5NO3 Cs O

O

r0 [Å] a 3.118(4)

H

OH

H

NH2

272

4 Molecules with Two Carbon Atoms

H(1)…O(3) H(2)…O(1)

1.78 1.79

Angle C(2)–O(2)–H(2)

θ0 [deg] a 121.7(3)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainty in units of the last significant digit. Distance between the centers of mass of the monomer subunits.

The rotational spectra of the binary bonded complex of formic acid with formamide were recorded by a pulsedjet Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 15 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 13 C, 15N, 13C/15N, 15N/D and D). Daly AM, Sargus BA, Kukolich SG (2010) Microwave spectrum and structural parameters for the formamideformic acid dimer. J Chem Phys 133(17):174304/1-174304/6 doi:10.1063/1.3501356

349 CAS RN: MGD RN: 521142 MW supported by ab initio calculations

Urea – hydrogen isocyanate (1/1) C2H5N3O2 essentially Cs O

N H

Distances O(2)…H(1) N(1)…O(2) N(1)…H(2) Angles N(1)–H(1)…O(2) C(2)=O(2)…H(1) N(2)–H(2)…N(1)

r0 [Å] a 1.866(11) 2.809(9) b 2.261(13) b

rs [Å] a 1.820(6) 2.762(9)

θ0 [deg] a

θs [deg] a

156.8(6) 112.5(8) 138.4(78) b

H2N

NH2

C O

151.2(23) 113.9(27)

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Dependent parameter.

The rotational spectra of the title complex were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of thirteen isotopic species (main, two 13C, 13C2, 15N, 15N2, 15N3, two 18O, 18O2, D, D4 and D5) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Mullaney JC, Medcraft C, Tew DP, Lewis-Borrell L, Golding BT, Walker NR, Legon AC, (2017) Cooperative hydrogen bonds form a pseudocycle stabilizing an isolated complex of isocyanic acid with urea.” Phys Chem Chem Phys 19(36):25080-25085

4 Molecules with Two Carbon Atoms

273

350 CAS RN: 58436-39-8 MGD RN: 132806 GED augmented by ab initio computations

Ethenylphosphine Vinylphosphine C2H5P Cs (I) C1 (II) H 2C

Bonds P–C P–H C=C C–H Bond angles H–P–H C–P–H(1) C–P–H(2) P–C–C Dihedral angle C=C–P…X f

PH2

a

rh1 [Å] Cs C1 1.829(1) 1.824(2) b c 1.412(7) 1.412(7) c c 1.343(3) 1.343(3) c 1.076(3) 1.076(3)

θh1 [deg] a

Cs 94.2(10) d 97.1(9) d 119.1(4) e

Cs 180.0

I

C1 95.0(10) d 96.9(9) d 97.5(9) d 126.8(3) e

τh1 [deg] a

II

C1 69.9(10) d

Reprinted with permission. Copyright 2009 American Chemical Society [a]. a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Difference to corresponding parameter of the main conformer was restrained to the value from MP2/6311++G** computation. c Derived from the refined average value of r(P–H) and r(C=C) and the differences between these distances, which were restrained to the values from computation as indicated above. d Restrained to the value from computation as indicated above. e Difference between the P–C=C angles was restrained to the value from computation as indicated above. f X is the bisector of the H–P–H angle. b

Two conformers, I and II, were detected in the previous MW study [b]. In the conformer I, the C=C–P–H dihedral angles are ±anticlinal (Cs overall symmetry), whereas in the conformer II, one the C=C–P–H dihedral angle is approximately synperiplanar and the other one is approximately anticlinal (C1 point-group symmetry). Both conformers were taken into account in the GED model. The GED experiment was carried out at 215 K. The ratio of the conformers was determined to be Cs : C1 = 65(5) : 35(5) (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/6-311++G** computation. a. Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612 b. Dréan P, Le Guennec M, López JC, Alonso JL, Denis JM, Kreglewski M, Demaison J (1994) Rotational spectrum, molecular constants, dipole moment, and internal rotation in vinylphosphine. J Mol Spectrosc 166:210-223.

274

4 Molecules with Two Carbon Atoms

351 CAS RN: 476003-91-5 MGD RN: 148797 MW supported by ab initio calculations

1,1'-Oxybismethane – argon (1/1) Dimethyl ether – argon (1/1) C2H6ArO Cs O H 3C

Distance Rcm c

r0 [Å] a 3.580(4)

rs [Å] b 3.577

Angle

θ0 [deg] a

θs [deg] b

α

d

78.8(9)

CH3

Ar

62.3

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit. Uncertainty was not given in the original paper. c Distance between Ar and the center-of-mass of the ether subunit. d Angle between O, the center-of-mass of ether and Ar. b

The rotational spectra of two isotopic species (D6 and 13C) were recorded by a pulsed supersonic-jet FTMW spectrometer in the spectral range between 9 and 18 GHz. The partial r0 structure, determined from the ground-state rotational constants of the 13C species together with the previously published rotational constants of the main isotopic species, was preferred to that one obtained with the rotational constants of the D6 species. The Ar atom was found to lie in the σv plane of dimethyl ether perpendicular to the COC plane, shifted towards the oxygen atom. It was suggested that the isotopic substitution effects make the data from the D6 isotopic species not directly compatible with those of the other species. Maris A, Ottaviani P, Melandri S, Caminati W, Costantini A, Lagana A, Pirani F (2009) Apparent conflicting indications on the conformation of dimethyl ether-argon from the rotational spectra of the d6 and 13C species. J Mol Spectrosc 257(1):29-33

352 CAS RN: 1186318-63-7 MGD RN: 211428 MW supported by ab initio calculations

1,1'-Thiobismethane – argon (1/1) Dimethyl sulfide – argon (1/1) C2H6ArS Cs S

Distance Rcm b

r0 [Å] a 3.796(3)

Angle

θ0 [deg] a

α

c

104.8(2)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit. Distance between the center-of-mass of the sulfide subunit and Ar. c Angle between S, the center-of-mass of sulfide and Ar. b

H 3C

CH3

Ar

4 Molecules with Two Carbon Atoms

275

The rotational spectra of the binary van der Waals complex were recorded by a supersonic-jet FTMW spectrometer in the spectral range between 3.7 and 24.1 GHz. The r0 structure was determined from the ground-state rotational constants of three isotopic species (main, 34S and 13C) under the assumption that the structure of the dimethyl sulfide subunit was not changed upon complexation. The V3 barrier to internal rotation of the methyl group was determined to be 736.17(32) cm-1. No Ar tunneling splitting was observed. Tatamitani Y, Sato A, Kawashima Y, Ohashi N, LoBue JM, Hirota E (2009) Rotational spectrum of the Ardimethyl sulfide complex. J Mol Spectrosc 257(1):11-19

353 CAS RN: 197388-51-5 MGD RN: 516513 GED augmented by QC computations

Bonds Si–Si Si–Br Si–C C–H

rh1 [Å] a 2.356(5) b 2.203(1) c 1.854(3) 1.098(4) b, c

Bond angles Br–Si–Br Si–Si–Br(4) Si–Si–C Si–C–H Br–Si–C Si–Si–Br(1) Si–Si–Br(2,3)

θh1 [deg] a

Dihedral and other angles Hʹ–C–Si–Si tilt(SiBr3) e

τh1 [deg] a

1,1,1,2-Tetrabromo-2,2-dimethyldisilane C2H6Br4Si Cs (staggered)

107.5(1) 106.1(4) b 109.2(8) b 112.8(9) b, c 111.1(5) b 106.3(7) d 113.8(4) d

62.8(12) b 5.1(7) b

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Restrained to the value from MP2/6-311+G* computation. c Average value. d Dependent parameter. e Tilt angle of the SiBr3 group away from the Br(4) atom. b

The GED experiment was carried out at Tnozzle = 356 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from HF/6-31G* computation. Masters SL, Atkinson SJ, Hölbling M, Hassler K (2013) Gas-phase molecular structure of 1,1,1,2-tetrabromo2,2-dimethyldisilane: Theoretical and experimental investigation of a super-halogenated disilane and computational investigation of the F, Cl and I analogues. Struct Chem 24 (4):1201-1206

276

4 Molecules with Two Carbon Atoms

354 CAS RN: MGD RN: 214560 MW augmented by ab initio calculations

1-Chloro-1-fluoroethane – water (1/1) C2H6ClFO C1 Cl O H

a

Distances O…F H(1)…F Rcm c O…H(3) O…H(4)

r0 [Å] 2.910(9) 2.140 b 3.756 b 2.753 b 2.842 b

Angles O…F–C H(1)–O…F O–H(1)…F H(1)…F–C O…F–C–Cl H(1)–O…F–C H(2)–O–H(1)…F

θ0 [deg] a

H 3C

H

F

87.4(1) 31(4) 136.2 b 98.7 b 156.7(2) -212(8) -149(5)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c Distance between the centers of mass of the monomer subunits. b

The rotational spectra of the binary complex of 1-chloro-1-fluoroethane with water were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 37 Cl, 18O, two D and D2); the remaining structural parameters were constrained to their MP2/6-311++G** values. Feng G, Evangelisti L, Favero LB, Grabow JU, Xia Z, Caminati W (2011) On the weak O–H⋅⋅⋅halogen hydrogen bond: a rotational study of CH3CHClF⋅⋅⋅H2O. Phys Chem Chem Phys 13(31):14092-14096

355 CAS RN: 406-34-8 MGD RN: 834380 MW augmented by QC calculations

2-Fluoroethanamine 2-Fluoroethylamine C2H6FN C1 F

NH2

Bonds C(1)–C(2) C(2)–N C(1)–F C(1)–H(5) C(1)–H(6) C(2)–H(7)

gauche-gauche r0 [Å] a 1.509(3) 1.466(3) 1.400(3) 1.093(2) 1.092(2) 1.098(2)

gauche-anti r0 [Å] a 1.516(3) 1.461(3) 1.398(3) 1.094(2) 1.094(2) 1.094(2)

4 Molecules with Two Carbon Atoms

277

C(2)–H(8) N–H(3) N–H(4)

1.095(2) 1.012(2) 1.015(2)

1.095(2) 1.014(2) 1.015(2)

Bond angles N–C(2)–C(1) F–C(1)–C(2) H(5)–C(1)–C(2) H(6)–C(1)–C(2) H(7)–C(2)–C(1) H(8)–C(2)–C(1) H(5)–C(1)–H(6) F–C(1)–H(6) F–C(1)–H(5) H(7)–C(2)–H(8) H(3)–N–C(2) H(4)–N–C(2) H(4)–N–H(3)

θ0 [deg] a

θ0 [deg] a

Dihedral angles F–C(1)–C(2)–N H(3)–N–C(2)–C(1)

τ0 [deg] a

τ0 [deg] a

109.8(5) 109.2(5) 111.5(5) 110.7(5) 108.4(5) 107.8(5) 110.6(5) 107.2(3) 107.4(2) 107.8(5) 110.6(5) 109.5(5) 107.1(5)

65.3(5) 179.7(5)

115.5(5) 109.3(5) 111.5(5) 111.3(5) 108.6(5) 108.1(5) 109.8(5) 107.1(3) 107.6(2) 107.1(5) 109.9(5) 110.6(5) 107.1(5)

60.9(5) -57.1(5)

Copyright 2010 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

gauche-gauche

gauche-anti

All five possible conformers, gauche-gauche (Ggꞌ), gauche-anti (Ga), anti-gauche (Ag), anti-anti (Aa) and gauche-gauche (Gg), were identified in the temperature-dependent IR vibrational spectra. The conformers are characterized by the synclinal (G) or anticlinal (A) F–C–C–N torsional angle and by the anticlinal or synclinal lp–N–C–C angles (lp is the electron lone pair on the nitrogen atom). The amounts of the Ggꞌ, Ga, Ag, Aa and Gg conformers were estimated to be 42(4), 32(1), 13(1), 5(1) and 3(1)%, respectively (at ambient temperature). The r0 structural parameters of each of the most stable conformers, gauche-gauche and gauche-anti, were determined by adjusting of the MP2_full/6-311+G(d,p) structure to the previously published ground-state rotational constants of one isotopic species; the C–H, N–H and C–F bond lengths were assumed at the ab initio value. Durig JR, Ganguly A, Zheng C, Gurigis GA, Herrebout WA, van der Veken BJ, Gounev TK (2010) Conformational and structural studies of 2-fluoroethylamine from temperature dependent FT-IR spectra of krypton and xenon solutions and ab initio calculations. J Mol Struct 968(1-3):36-47

356 CAS RN: MGD RN: 158115 MW supported by

Oxybismethane – dinitrogen monoxide (1/1) Dimethyl ether – dinitrogen monoxide (1/1) C2H6N2O2 Cs

278

4 Molecules with Two Carbon Atoms

ab initio calculations

O H 3C

CH3

N

O

N

a

Distances N(1)…O(2) Rcm b O(1)…H N(2)…H

r0 [Å] 2.813 3.354 2.95 3.15

Angles O(2)…N(1)=O(1) N(1)…O(2)–C

θ0 [deg] a 88.2 125.8

Reprinted with permission. Copyright 2009 American Chemical Society. a b

Uncertainties were not given in the original paper. Distance between the centers of mass of the monomer subunits.

The rotational spectrum of the binary complex of dimethyl ether with dinitrogen monoxide was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 19 GHz. The r0 structure was determined from the experimental ground-state rotational constants of four isotopic species (main and three 15N) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The rigid structure formed by three weak intermolecular bonds was indicated due to the absence of internal rotation splittings. Yamanou K, Tatamitani Y, Ogata T (2009) Three intermolecular bonds form a weak but rigid complex: O(CH3)2⋅⋅⋅N2O. J Phys Chem A 113(15):3476-3480

357 CAS RN: 64-17-5 MGD RN: 492191 MW augmented by QC calculations

Bonds O(3)–H(4) C(2)–O(3) C(1)–C(2) C(1)–H(7) C(1)–H(8) C(1)–H(9) C(2)–H(5) C(2)–H(6) Bond angles C(2)–O(3)–H(4) O(3)–C(2)–H(5) O(3)–C(2)–H(6) C(1)–C(2)–O(3) C(1)–C(2)–H(5) C(1)–C(2)–H(6) H(5)–C(2)–H(6)

Ethanol Ethyl alcohol C2H6O Cs (anti) Cs (gauche)

anti r0 [Å] a 0.962(3) 1.432(3) 1.519(3) 1.095(2) 1.094(2) 1.094(2) 1.099(2) 1.099(2)

gauche r0 [Å] a 0.963(3) 1.430(3) 1.523(3) 1.096(2) 1.097(2) 1.094(2) 1.100(2) 1.093(2)

θ0 [deg] a

θ0 [deg] a

107.5(5) 110.8(5) 110.8(5) 107.6(5) 109.6(5) 109.6(5) 108.5(5)

107.0(5) 110.4(5) 105.2(5) 112.5(5) 110.2(5) 110.5(5) 107.7(5)

H 3C

OH

4 Molecules with Two Carbon Atoms

279

H(7)–C(1)–C(2) H(8)–C(1)–C(2) H(9)–C(1)–C(2) H(8)–C(1)–H(9) H(7)–C(1)–H(8) H(7)–C(1)–H(9)

110.0(5) 109.7(5) 109.7(5) 109.0(5) 109.0(5) 109.0(5)

110.7(5) 110.8(5) 110.2(5) 108.4(5) 107.9(5) 108.8(5)

Dihedral angles H(4)–O(3)–C(2)–C(1) H(7)–C(1)–C(2)–O(3)

τ0 [deg]

τ0 [deg] a

180 180

56.9(5) 177.4(5)

Copyright 2010 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

anti

gauche

Two conformers, anti and gauche, characterized by the antiperiplanar and synclinal H–O–C–C dihedral angles, respectively, were detected by temperature-dependent IR vibrational spectroscopy; the amount of the anti conformer was estimated to be 40(1) % (at ambient temperature). The r0 structural parameters of the anti and gauche conformers were obtained by fitting the MP2_full/6311+G(d,p) structures to the previously published experimental ground-state rotational constants of five and one isotopic species, respectively. Durig JR, Deeb H, Darkhalil ID, Klaassen JJ, Gounev TK, Ganguly A (2011) The r0 structural parameters, conformational stability, barriers to internal rotation, and vibrational assignments for trans and gauche ethanol. J Mol Struct 985(2-3):202-210 MW augmented by ab initio calculations

Cs (anti)

Bonds C–C C–O O–H C(1)–H(7) C(1)–H(8) C(1)–H

r see [Å] a 1.5081(14) 1.4239(13) 0.9589(10) 1.0905(10) 1.0883(3) 1.0940(3)

Bond angles C–C–O C–O–H C(2)–C(1)–H(7) C(2)–C(1)–H(8) C(2)–C(1)–H H–C(2)–H H(7)–C(1)–H(8)

θ see [deg] a

107.59(1) 107.89(10) 110.40(7) 110.27(5) 109.83(31) 108.17(9) 108.58(5)

280

4 Molecules with Two Carbon Atoms

H(8)–C(1)–H(9)

108.68(11)

Copyright 2014 Wiley Periodicals, Inc. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure of the anti conformer, characterized by the antiperiplanar H–O–C– C torsional angle, was determined from the previously published experimental ground-state rotational constants of 14 isotopic species accounting for rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. The obtained structure seems to be accurate as confirmed by comparison with published calculations of CCSD(T)_ae/cc-pCV5Z quality, although large-amplitude motions of the hydroxyl and methyl groups increased its uncertainty. Vogt N, Demaison J, Vogt J, Rudolph HD (2014) Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method: structure of molecules containing the OH or the CH3 group. J Comput Chem 35(32):2333-2342

358 CAS RN: 115-10-6 MGD RN: 633846 MW augmented by ab initio calculations

1,1’-Oxybismethane Dimethyl ether C2H6O C2v O H 3C

Bonds C–O C–H(1) C–H(2)

r see [Å] a 1.40660(2) 1.0865(2) 1.09506(7)

Bond angles C–O–C O–C–H(1) O–C–H(2) H(1)–C–H(2) H(2)–C–H(2ꞌ)

θ see [deg] a

Dihedral angle C–O–C–H(2)

CH3

111.100(3) 107.515(14) 111.191(3) 109.177(5) 108.552(10)

τ see [deg] a 60.542(6)

Copyright 2014 Wiley Periodicals, Inc.. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure was determined from the previously published experimental groundstate rotational constants of 16 isotopic species taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields.

4 Molecules with Two Carbon Atoms

281

Vogt N, Demaison J, Vogt J, Rudolph HD (2014) Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method: structure of molecules containing the OH or the CH3 group. J Comput Chem 35(32):2333-2342 359 CAS RN: 67-68-5 MGD RN: 693554 MW augmented by QC calculations

Sulfinylbis(methane) Dimethyl sulfoxide C2H6OS Cs O

Bonds S=O S–C C–H(1) C–H(2) C–H(3)

r e [Å] a 1.4804(5) 1.7964(4) 1.0868(13) 1.0888(10) 1.0880(13)

Bond angles O=S–C S–C–H(1) S–C–H(2) S–C–H(3) C–S–C H(1)–C–H(2) H(1)–C–H(3) H(2)–C–H(3)

θ see [deg] a

Dihedral angles O=S–C–H(1) O=S–C–H(2) O=S–C–H(3) C–S–C–H(1) C–S–C–H(2) C–S–C–H(3)

τ see [deg] a

S

se

H 3C

CH3

106.55(2) 106.96(10) 108.48(10) 109.62(10) 96.01(2) 110.12(15) b 110.25(14) b 111.29(13) b

67.85(12) -50.90(10) -172.61(10) -177.13(12) b -58.37(10) b 63.34(10) b

Copyright 2014 with permission from Elsevier [a].

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. se

The semiexperimental equilibrium structure r e was determined from the previously published experimental ground-state rotational constants of ten isotopic species [b,c] taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the B3LYP/6-311+(3df,2pd) harmonic and anharmonic (cubic) force fields. Several small Cartesian coordinates were constrained (with appropriate uncertainties) to the best estimated ab initio values (CCSD(T)_ae/cc-pwCV(T→Q)Z, where extrapolation from the triple- to quadruple-ζ basis set was done at the MP2 level of theory). a.Vogt N, Demaison J, Rudolph HD (2014) Semiexperimental equilibrium structure of the oblate-top molecules dimethyl sulfoxide and cyclobutene. J Mol Spectrosc 297:11-15 b. Feder W, Dreizler H; Rudolph HD, Typke V (1969) rs-Struktur von Dimethylsulfoxid im Vergleich zur r0Struktur. Z Naturforsch A 24:266-278 c. Kretschmer U (1995) The 33S nuclear quadrupole hyperfine coupling in the rotational spectrum of 33S dimethyl sulfoxide. Z Naturforsch A 50(7):666-668

282

4 Molecules with Two Carbon Atoms

360 CAS RN: 77-78-1 MGD RN: 993920 MW supported by ab initio calculations

Sulfuric acid dimethyl ester Dimethyl sulfate C2H6O4S C2 O

Bonds S(1)=O(2) S(1)–O(4) O(4)–C O(4)...H(1) O(3)...H(2)

r0 [Å] a 1.416(2) 1.575(3) 1.447(3) 2.692 b 2.609 b

rs [Å] a 1.417(2) 1.570(3) 1.461(2)

Bond angles O(2)=S(1)=O(3) O(4)–S(1)=O(2) C–O(4)–S(1) O(4)–S(1)–O(5)

θ0 [deg] a

θs [deg] a

Dihedral angles O(4)–S(1)=O(2)=O(3) C–O(4)–S(1)–O(5) C–O(4)–S(1)=O(2)

τ0 [deg] a

τs [deg] a

123.1(3) 109.9(1) 116.6(2) 101.6 b

H 3C

O

S O

O

CH3

122.8(3) 110.2(3) 115.7(3) 101.7(2)

124.7(2) 72.1(3) 38.9 b

124.5 71.8 39.2

Copyright 2011 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the title compound was recorded by a pulsed supersonic jet FTMW spectrometer in the frequency region 6 to 18 GHz. The r0 and partial rs structures were determined from the ground-state rotational constants of five isotopic species (main, 13C, two 18O and 34S). The barrier to internal rotation of the two methyl groups was determined to be 4.731(6) kJ mol-1. Favero LB, Evangelisti L, Feng G, Spada L, Caminati W (2011) Conformation and internal motions of dimethyl sulfate: A microwave spectroscopy study. Chem Phys Lett 517(4-6):139-143

361 CAS RN: 75-18-3 MGD RN: 211219 MW augmented by ab initio calculations

1,1'-Thiobismethane Dimethyl sulfide C 2H 6S C2v S

H 3C

Bonds C–S C–H(1) C–H(2)

r0 [Å] a 1.8075(3) 1.097(12) 1.0896(11)

r m [Å] a 1.8002(15) 1.0799(37) 1.0897(7) ( 2)

r e [Å] a 1.79863(13) 1.08857(38) 1.08972(47) se

CH3

4 Molecules with Two Carbon Atoms

Bond angles C–S–C S–C–H(1) S–C–H(2) H(2)–C–H(2) H(1)–C–H(2)

θ0 [deg] a

Dihedral angle H(2)–C–S–C

τ0 [deg] a

99.09(3) 105.63(94) 110.46(5)

119.58(9)

283

θ (m2) [deg] a

θ see [deg] a

τ (m2) [deg] a

τ see [deg] a

98.65(11) 107.35(31) 110.80(8)

119.26(13)

98.58000(81) 107.4196(69) 110.688(29) 109.730(16) b 109.130(54) b

119.053(44)

Copyright 2010 with permission from Elsevier. a b

Parenthesized uncertainties in units of the last digit. Derived parameter. ( 2)

The r0 and r m structures were determined from the previously published experimental ground-state rotational se

constants of twenty isotopic species. The semiexperimental equilibrium structure r e was determined taking into account rovibrational corrections calculated with harmonic and anharmonic (cubic) force fields computed at the MP2 level of theory in conjunction with the cc-pVTZ (for C and H) and cc-pV(T+d) (for S) basis sets. Demaison J, Margulès L, Rudolph HD (2010) Accurate determination of an equilibrium structure in the presence of a small coordinate: The case of dimethyl sulfide. J Mol Struct 978(1-3) 229-233

362 CAS RN: 75-04-7 MGD RN: 735236 MW augmented by ab initio calculations

Bonds C(1)–C(2) C(2)–N C(1)–H(4) C(1)–C(5) C(1)–H(6) C(2)–H(7) C(2)–H(8) N–H(9) N–H(3) Bond angles C(1)–C(2)–N H(4)–C(1)–C(2) H(5)–C(1)–C(2) H(6)–C(1)–C(2) H(7)–C(2)–C(1) H(8)–C(2)–C(1) H(7)–C(2)–N H(8)–C(2)–N H(9)–N–C(2) H(3)–N–C(2)

Ethanamine Ethylamine C 2H 7N Cs (anti) C1 (gauche)

anti r0 [Å] a 1.526(3) 1.467(3) 1.099(2) 1.098(2) 1.098(2) 1.101(2) 1.101(2) 1.017(3) 1.017(3)

gauche r0 [Å] a 1.520(3) 1.471(3) 1.098(2) 1.099(2) 1.097(2) 1.108(2) 1.102(2) 1.018(3) 1.019(3)

θ0 [deg] a

θ0 [deg] a

115.5(5) 111.6(5) 111.1(5) 111.1(5) 111.1(5) 111.1(5) 106.7(5) 106.7(5) 110.8(5) 110.8(5)

110.2(5) 111.1(5) 110.7(5) 110.2(5) 110.3(5) 110.7(5) 112.5(5) 106.9(5) 111.2(5) 110.3(5)

H 3C

NH2

284

4 Molecules with Two Carbon Atoms

H(4)–C(1)–H(5) H(4)–C(1)–H(6) H(5)–C(1)–H(6) H(7)–C(2)–H(8) H(9)–N–H(3)

107.6(5) 107.6(5) 107.5(5) 105.1(5) 105.1(5)

107.7(5) 108.8(5) 108.1(5) 106.0(5) 107.0(5)

Dihedral angles H(4)–C(1)–C(2)–N H(5)–C(1)–C(2)–N H(6)–C(1)–C(2)–N H(7)–C(2)–C(1)–N H(8)–C(2)–C(1)–N H(9)–N–C(2)–C(1) H(3)–N–C(2)–C(1)

τ0 [deg] a

τ0 [deg] a

180.0(5) -59.81(5) 59.81(5) 121.7(5) -121.7(5) 58.12(5) -58.12(5)

177.9(5) -62.42(5) 57.11(5) 124.9(5) -118.0(5) –179.9(5) 61.41(5)

Copyright 2014 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

anti

gauche

Two conformers, anti and gauche, with different orientation of the amino group, were identified by the temperature-dependent Raman vibrational spectroscopy. The amount of the gauche conformer was estimated to be 60 % (at ambient temperature). The r0 structure of each conformer was determined by adjusting the MP2_full/6-311+G(d,p) structure to the previously determined ground-state rotational constants of four isotopic species. Darkhalil ID, Nagels N, Herrebout WA, van der Veken BJ, Gurusinghe RM, Tubergen MJ, Durig JR (2014) Microwave spectra and conformational studies of ethylamine from temperature dependent Raman spectra of xenon solutions and ab initio calculations. J Mol Struct 1068:101-111

363 CAS RN: 676-59-5 MGD RN: 120580 MW augmented by QC calculations

Dimethylphosphine C2H7P Cs H P

Bonds P–H P–C C–H(1) C–H(2) C–H(3)

r0 [Å] a 1.4117(30) 1.8477(30) 1.0929(20) 1.9028(20) 1.0927(20)

Bond angles H–P–C C–P–C

θ0 [deg] a

98.60(50) 99.88(50)

H3C

CH3

4 Molecules with Two Carbon Atoms

P–C–H(1) P–C–H(2) P–C–H(3) H(1)–C–H(2) H(1)–C–H(3) H(2)–C–H(3)

109.10(50) 112.92(50) 109.75(50) 108.75(50) 107.43(50) 108.71(50)

Dihedral angles H–P–C…C H(1)–C–P–H

τ0 [deg] a

285

100.36(50) 171.96(50)

Copyright 2012 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of two isotopic species (main and D6). The barrier to internal rotation of the methyl group was determined to be 2.29 kcal mol-1 from the fundamental methyl torsion frequency assigned from the IR spectrum of the gas. Panikar SS, Deodhar BS, Sawant DK, Klaassen JJ, Deng J, Durig JR (2013) Raman and infrared spectra, r0 structural parameters, and vibrational assignments of (CH3)2PX where X = H, CN, and Cl. Spectrochim Acta A 103:205-215

364 CAS RN: 107-15-3 MGD RN: 301077 MW augmented by QC calculations

1,2-Ethanediamine Ethylenediamine C2H8N2 C1 (gauche-gauche-gauche) C1 (gauche-gauche-anti) H 2N

Bonds N(1)–C(2) C(2)–C(3) C(3)–N(4) N(1)–H(1) N(1)–H(2) C(2)–H(3) C(2)–H(4) C(3)–H(5) C(3)–H(6) N(4)–H(7) N(4)–H(8) Bond angles N(1)–C(2)–C(3) N(4)–C(3)–C(2) H(1)–N(1)–C(2) H(2)–N(1)–C(2) H(3)–C(2)–N(1) H(4)–C(2)–N(1) H(3)–C(2)–C(3)

gꞌGꞌgꞌ r0 [Å] a 1.472(3) 1.526(3) 1.464(3) 1.015(2) 1.014(2) 1.099(2) 1.093(2) 1.095(2) 1.103(2) 1.014(2) 1.015(2)

gꞌGꞌa r0 [Å] a 1.470(3) 1.532(3) 1.463(3) 1.015(2) 1.014(2) 1.101(2) 1.095(2) 1.095(2) 1.097(2) 1.016(2) 1.015(2)

θ0 [deg] a

θ0 [deg] a

109.7(5) 109.5(5) 110.1(5) 110.9(5) 113.6(5) 107.7(5) 109.4(5)

109.7(5) 115.3(5) 110.0(5) 111.1(5) 114.0(5) 107.2(5) 109.3(5)

NH2

286

4 Molecules with Two Carbon Atoms

H(4)–C(2)–C(3) H(5)–C(3)–C(2) H(6)–C(3)–C(2) H(5)–C(3)–N(4) H(6)–C(3)–N(4) H(7)–N(4)–C(3) H(8)–N(4)–C(3) H(1)–N(1)–H(2) H(3)–C(2)–H(4) H(5)–C(3)–H(6) H(7)–N(4)–H(8)

108.2(5) 109.2(5) 108.3(5) 108.7(5) 113.8(5) 111.0(5) 108.3(5) 105.5(5) 108.1(5) 107.2(5) 105.8(5)

109.0(5) 109.4(5) 108.6(5) 109.0(5) 107.6(5) 108.4(5) 109.7(5) 106.9(5) 107.6(5) 106.7(5) 106.4(5)

Dihedral angle N(1)–C(2)–C(3)–N(4)

τ0 [deg] a

τ0 [deg] a

63.5(5)

59.7(5)

Copyright 2010 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

gauche-gauche-gauche

gauche-gauche-anti

Three conformers were identified in the temperature-dependent IR vibrational spectra. These conformers, gauche-gauche-gauche (gꞌGꞌgꞌ), gauche-gauche-anti (gꞌGꞌa) and gauche-gauche-gauche (gꞌGꞌg), are characterized by the different synclinal N–C–C–N and lp–N–C–C angles (lp is electron lone pair of nitrogen atom), except for the anticlinal lp–N(4)–C–C angle in the gꞌGꞌa conformer. The amounts of the gꞌGꞌgꞌ, gꞌGꞌa and gꞌGꞌg conformers at ambient temperature were estimated to be 47(1), 36(2) and 13(2) %, respectively. The r0 structural parameters of each of the two most stable conformers were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of one isotopic species. Durig JR, Panikar SS, Iwata T, Gounev TK (2010) Conformational stability of ethylenediamine from temperature dependent infrared spectra of liquid xenon solutions, r0 structural parameters, ab initio calculations, and vibrational assignments. J Mol Struct 984(1-3):58-67

365 CAS RN: MGD RN: 494553 MW supported by ab initio calculations

Formamide – water (2/1) C2H8N2O3 C1

O

O H

Distances O(1)=C(2) C(2)–N(3) O(7)–C(8) C(8)–N(9) O(7)...H(5)

r0 [Å]a 1.2671(84) 1.3285(69) 1.2671(84) 1.3285(69) 1.8571(58)

rs .[Å]a 1.344(4) 1.340(4)

H

NH2

2

H

4 Molecules with Two Carbon Atoms

O(7)...N(3) H(1)...O(14) O(1)...H(2) N(3)...C(8) N(9)...O(14) O(14)–H(3) H(2)...C(2)

2.8260(74) 1.8077(78) 1.7877(89)

Angles O(1)=C(2)–N(3) O(7)–C(8)–N(9) O(7)…H(5)–N(3) C(8)–O(7)…H(5) N(9)–H(1)…O(14) H(1)…O(14)–H(2) H(2)…O(1)–C(2) O(14)–H(2)…O(1)

θ0 [deg] a

Dihedral angle H(3)–O(14)…O(1)=C(2)

τ0 [deg] a

287

3.945(2) 2.91(3) 0.87(3) 2.789(3)

126.51(37) 126.51(37) 159.27(48) 139.97(54) 179.98(38) 115.28(37) 126.66(68) 179.49(56)

123.04(44)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the ternary complex were recorded in a supersonic beam by an FTMW spectrometer in the frequency range between 5 and 13 GHz. According to predictions at the MP2 level of theory the most stable conformer could not be detected because it has an inversion center and consequently no microwave spectrum. Only the second low-energy conformer was identified in the spectrum. The partial r0 and rs structures of this conformer were determined from the ground-state rotational constants of eight isotopic species (main, two 13C, 18O, two 15N, 15N2 and D). Blanco S, Pinacho P, López JC (2016) Hydrogen-bond cooperativity in formamide2-water: A model for watermediated interactions. Angew Chem 128(32):9477-9481; Angew Chem Int Ed 55(32):9331-9335

366 CAS RN: 5518-62-7 MGD RN: 137132 MW augmented by QC calculations

1,2-Ethanediylbisphosphine 1,2-Diphosphinoethane C2H8P2 C1 (gꞌAa, aGꞌgꞌ) C2 (gꞌAgꞌ, aGꞌa) H 2P

Bonds P(1)–C(2) C(2)–C(3) C(3)–P(4) P(1)–H(1) P(1)–H(2) C(2)–H(3) C(2)–H(4) C(3)–H(5) C(3)–H(6) P(4)–H(7)

gꞌAa r0 [Å] a 1.870(3) 1.535(3) 1.863(3) 1.412(3) 1.412(3) 1.095(2) 1.093(2) 1.096(2) 1.096(2) 1.412(3)

gꞌAgꞌ r0 [Å] a 1.866(3) 1.536(3) 1.866(3) 1.412(3) 1.412(3) 1.095(2) 1.094(2) 1.095(2) 1.094(2) 1.412(3)

aGꞌgꞌ r0 [Å] a 1.858(3) 1.534(3) 1.866(3) 1.411(3) 1.413(3) 1.096(2) 1.096(2) 1.094(2) 1.096(2) 1.411(3)

aGꞌa r0 [Å] a 1.859(3) 1.536(3) 1.859(3) 1.402(3) 1.405(3) 1.086(2) 1.088(2) 1.086(2) 1.088(2) 1.402(3)

PH2

288

4 Molecules with Two Carbon Atoms

P(4)–H(7)

1.412(3)

1.412(3)

1.410(3)

1.405(3)

Bond angles P(1)–C(2)–C(3) C(2)–C(3)–P(4) H(1)–P(1)–H(2) H(1)–P(1)–C(2) H(2)–P(1)–C(2) H(3)–C(2)–H(4) H(3)–C(2)–P(1) H(4)–C(2)–P(1) H(3)–C(2)–C(3) H(4)–C(2)–C(3) H(5)–C(3)–H(6) H(5)–C(3)–C(2) H(6)–C(3)–C(2) H(5)–C(3)–P(4) H(6)–C(3)–P(4) H(7)–P(4)–H(8) H(7)–P(4)–C(3) H(8)–P(4)–C(3)

θ0 [deg] a

θ0 [deg] a

θ0 [deg] a

θ0 [deg] a

Dihedral angle P(1)–C(2)–C(3)–P(4)

τ0 [deg] a

τ0 [deg] a

τ0 [deg] a

110.5(5) 115.5(5) 94.5(5) 96.5(5) 97.6(5) 107.3(5) 106.4(5) 113.0(5) 109.6(5) 109.9(5) 106.0(5) 110.4(5) 110.3(5) 106.0(5) 108.1(5) 93.9(5) 96.5(5) 96.4(5)

175.3(5)

110.4(5) 110.4(5) 94.5(5) 97.7(5) 96.5(5) 107.4(5) 107.4(5) 111.3(5) 109.8(5) 110.1(5) 107.4(5) 109.8(5) 110.1(5) 107.4(5) 111.3(5) 94.5(5) 97.7(5) 96.5(5)

171.1(5)

117.0(5) 113.7(5) 94.1(5) 97.3(5) 96.4(5) 106.1(5) 106.9(5) 106.1(5) 110.1(5) 109.4(5) 109.2(5) 110.2(5) 108.8(5) 111.5(5) 105.7(5) 94.4(5) 96.3(5) 98.8(5)

118.5(5) 118.5(5) 108.0(5) 119.1(5) 100.1(5) 114.7(5) 108.8(5) 105.8(5) 98.4(5) 110.4(5) 114.7(5) 98.4(5) 110.4(5) 108.8(5) 105.8(5) 108.0(5) 119.1(5) 100.1(5)

τ0 [deg] a

66.9(5)

74.6(5)

Copyright 2012 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

gꞌAa

gꞌAgꞌ

aGꞌgꞌ

aGꞌa

The temperature-dependent Raman vibrational spectra indicated the presence of six conformers differing by the orientations of the electron lone pair of phosphor with respect to the C–C bond (anti (a) or gauche (g)) and by the conformation of the P–C–C–P chain (anti (A) or gauche (G)). The rotational constants of four conformers (gꞌAa, gꞌAgꞌ, aGꞌgꞌ and aGꞌa) were published previously. The r0 structures of these conformers were determined by adjusting the MP2_full/6-311+G(d,p) structures to the twelve rotational constants. Durig JR, Panikar SS, Purohit SS, Pai TH, Kalasinsky VF (2013) Conformational stabilities from variable temperature Raman spectra, r0 structural parameters and vibrational assignments of 1,2-diphosphinoethane. J Mol Struct 1033:19-26

4 Molecules with Two Carbon Atoms

289

367 CAS RN: MGD RN: 349792 MW augmented by ab initio calculations

Ethanol – ammonia (1/1) C2H9NO Cs (anti) C1 (gauche) N

N…O

r0 [Å]a anti 2.960(1)

Angle

θ0 [deg]a

Distance

ϕb

anti 109.1(1)

H 3C

OH

H

H H

gauche 3.052(2)

gauche 106.8(1)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit. Angle between the N⋅⋅⋅H–O direction and the C–O bond

anti

gauche

The rotational spectra of the complex were recorded by a pulsed-jet FTMW spectrometer in the frequency range between 8 and 16.5 GHz. Two conformers, anti and gauche, characterized by the antiperiplanar and synclinal C–C–O–H torsional angles, respectively, were identified. The partial r0 structure of each conformer was determined from the ground-state rotational constants of two isotopic species (main and 15N); the remaining structural parameters were assumed at the values from MP2/6311++G** calculations. The anti complex exhibits the tunnelling effects due to the internal rotation of the ammonia and methyl group; the barrier height for the methyl rotation was determined to be 13.5(2) kJ mol-1. A small splitting of rotational transition for the gauche conformer was assigned to the tunnelling trough the barrier between the two equivalent minima on PES. Giuliano BM, Favero LB, Maris A, Caminati W (2012) Shapes and internal dynamics of the 1:1 adducts of ammonia with trans and gauche ethanol: A rotational study. Chem Eur J 18(40):12759-12763

368 CAS RN: 74-94-2 MGD RN: 363448 GED augmented by ab initio computations

Bonds C–H N–H B–H C–N N…B

ra3,1 [Å] a 1.080(2) b 1.023(9) c 1.216(7) b,c 1.467(2) 1.615(4)

Trihydro(N-methylmethanamine)boron N-Methylmethanamine – borane (1/1) C2H10BN Cs CH3 NH H 3C

BH3

290

Bond angles B–N–C N–C–H H–C–H N–B–H H–B–H H–N–C H–N–B C–N–C N–C–H(3) N–C–H(4) N–C–H(5) H(3)–C–H(5) H(4)–C–H(5) N…B–H(1) N…B–H(2)

4 Molecules with Two Carbon Atoms

θa3,1 [deg] a

111.9(2) 110.6(3) b 109.8(9) b,c 105.8(9) b 113.5(10) c 107.2(5) c 105.8(9) c 112.4(4) d 112.2(4) d,e 110.2(4) d,e 109.2(4) d,e 110.5(10) d,f 109.1(10) d,f 106.2(9) d,g 105.5(10) d,g

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value. c Restrained to the value from MP2_full/aug-cc-pVQZ computation. d Dependent parameter. e Differences between the N–C–H bond angles were restrained to the values from computation as indicated above. f Difference between the H–C–H bond angles was restrained to the value from computation as indicated above. g Difference between the N–B–H bond angles was restrained to the value from computation as indicated above. b

The GED experiment was carried out at the nozzle temperatures of 373 and 378 K at the long and short nozzleto-film distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆ra3,1 = ra − ra3,1, were calculated with the HF/6-31G* harmonic and anharmonic (cubic) force constants taking into account non-linear kinematic effects. Aldridge S, Downs AJ, Tang CY, Parsons S, Clarke MC, Johnstone RDL, Robertson HE, Rankin DWH, Wann DA (2009) Structures and aggregation of the methylamine-borane molecules, MenH3-nN·BH3 (n=1-3), studied by X-ray diffraction, gas-phase electron diffraction, and quantum chemical calculations. J Am Chem Soc 131(6):2231-2243

369 CAS RN: 17702-35-1 MGD RN: 468154 GED augmented by QC computations

9,12-Diiodo-1,2-dicarbadodecaborane(12) C2H10B10I2 C2v I

B

Bonds C–C B–C B–B B–I C–H B–H

a,b

re [Å] 1.621(18) 1.699(10) c 1.778(12) c 2.139(8) 1.088(12) c 1.183(13) c

a

rg [Å] 1.637(18) 1.715(10) c 1.793(12) c 2.148(8) 1.108(12) c 1.205(13) c

I

BH

B

HB

BH

HB

BH

HB

BH BH C H

CH

4 Molecules with Two Carbon Atoms

Bond angles C–C–B C–C–B C–B–C C–B–B C–B–B B–C–B B–C–B B–B–B B–B–B B–B–I C–C–H B–B–H C–B–H

291

θe [deg] a,b 61.8(1) d 111.7(4) e 56.4(6) 58.4(4) d 103.9(6) e 63.2(5) d 116.2(6) e 60.0(4) d 108.0(6) e 121.8(4) c 116.0(7) c 123.6(7) c 118.2(7) c

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. The refined parameters were constrained to the values from MP2/SDB-cc-pVTZ computation. c Average value of all geometrical parameters of this type. d Average value of the narrow angles of this type. e Average value of the wide angles of this type. b

The GED experiment was carried out at Tnozzle of 479…482 K. Z-matrix in Cartesian coordinates was used in the fitting. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with the B3LYP/SDB-cc-pVTZ harmonic and anharmonic (cubic) force constants taking into account non-linear kinematic effects. Vishnevskiy YV, Tikhonov DS, Reuter CG, Mitzel NW, Hnyk D, Holub J, Wann DA, Lane PD, Berger RJF, Hayes SA (2015) Influence of antipodally coupled iodine and carbon atoms on the cage structure of 9,12-I2closo-1,2-C2B10H10: An electron diffraction and computational study. Inorg Chem 54 (24):11868-11874

370 CAS RN: 16872-09-6 MGD RN: 625729 MW supported by DFT calculations

1,2-Dicarba-closo-dodecaborane(12) o-Carborane C2H12B10 C2v B

B

Bonds B(3)–B(4) B(4)–B(5) B(4)–B(9) B(4)–B(10) B(3)–B(9) B(9)–B(10) B(10)–B(12)

rs [Å] a 1.777(5) 1.778(2) 1.779(5) 1.777(8) 1.750(2) 1.790(1) 1.780(2)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

B B

B B B

B B

B

292

4 Molecules with Two Carbon Atoms

The rotational spectra of 1,2-dicarba-closo-docecaborane were recorded at room temperature by a Starkmodulated MW spectrometer in the frequency region between 32 and 88 GHz. The rs structure of the boron-cage was determined from ground-state rotational constants of five isotopic species (main and four 10B). Samdal S, Møllendal H, Hnyk D, Holub J (2011) Microwave spectra and structures of 1,2-(ortho)- and 1,7(meta)-carborane, C2B10H12. J Phys Chem A 115(15):3380-3385

371 CAS RN: 16986-24-6 MGD RN: 266279 MW supported by DFT calculations

Bonds B(2)–B(3) B(2)–B(6) B(3)–B(4) B(3)–B(8) B(3)–B(9) B(4)–B(9) B(9)–B(10)

1,7-Dicarba-closo-dodecaborane(12) m-Carborane C2H12B10 C2v B B

a

rs [Å] 1.761(8) 1.816(2) 1.778(5) 1.759(2) 1.775(8) 1.794(1) 1.821(2)

B B B

B B B

B

B

Reprinted with permission. Copyright 2011 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of 1,7-dicarba-closo-docecaborane were recorded at room temperature in natural abundance by a Stark-modulated MW spectrometer in the region between 24 and 80 GHz. The rs structure of the boron-cage was determined from the ground-state rotational constants of five isotopic species (main and four 10B). Samdal S, Møllendal H, Hnyk D, Holub J (2011) Microwave spectra and structures of 1,2-(ortho)- and 1,7(meta)-carborane, C2B10H12. J Phys Chem A 115(15):3380-3385 372 CAS RN: 75572-47-3 MGD RN: 517417 GED augmented by QC computations

Bonds C(1)–C(2) C(1)–B(4) B(5)–B(9) B(3)–B(4) B(4)–B(8) B(9)–B(12) B(8)–B(9) B(9)–S(13) B(12)–S(14) B(3)–H C(1)–H S(13)–H S(14)–H

9,12-Dimercapto-1,2-dicarbadodecaborane(12) C2H12B10S2 (see remark)

rh1 [Å] a,b 1.636(5) 1.713(5) 1.784(5) 1.780(4) 1.794(5) 1.814(7) 1.810(6) 1.845(6) 1.845(6) 1.201(6) 1.102(6) 1.356(13) 1.356(13)

4 Molecules with Two Carbon Atoms

Angles B(12)–B(9)–B(5) B(9)–B(12)–S(14) B(12)–B(9)–S(13) B(12)–S(14)–H B(9)–S(13)–H C–C–H B(5)–B(4)–H 180 – (X…B–H) c

θh1 [deg] a,b

Dihedral angle H–S(13)…S(14)–H

τh1 [deg] a

293

107.6(2) 122.5(6) 126.3(8) 95.4(14) 95.4(14) 116.3(5) 119.6(4) 7.2(7)

93.1(196)

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Differences between similar parameters were restrained to the values from MP2_full/6-311++G(3df,3pd) computation. c X is the center of the B(4)B(5)B(7)B(11) plane. b

The GED experiment was carried out at Tnozzle of 488 and 503 K at the long and short nozzle-to-film distances, respectively. The carbaborane cage was assumed to have local C2v symmetry (with only the SH fragments breaking this symmetry). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using the B3LYP/6-311++G(d,p) harmonic force field. Wann DA, Lane PD, Robertson HE, Baše T, Hnyk D (2013) The gaseous structure of closo-9,12-(SH)2-1,2C2B10H10, a modifier of gold surfaces, as determined using electron diffraction and computational methods. Dalton Trans 42 (33):12015-12019

373 CAS RN: 17653-38-2 MGD RN: 514464 GED augmented by QC computations

6,8-Dicarbanonaborane(13) C2H13B7 Cs H

Bonds B(2)–B(3) B(3)–B(7) B(3)–B(8) B(1)–B(2) B(2)–C(6) B(2)–B(7) B(2)–B(5) B(5)–C(6) C(6)–B(7) B(7)–B(8) B(8)–Hʹ B(7)–Hʹʹ B(8)–Hʹʹ C(6)–H′

rh1 [Å] a 1.788(4) b 1.816(6) b 1.719(7) b 1.721(7) b 1.684(5) b 1.794(4) b 1.742(8) b 1.678(10) b 1.750(9) b 1.839(8) b 1.190(2)c 1.397(3) c 1.333(17) c 1.089(3) c

H

H B

HB

BH

HB

HB

BH

B H

294

4 Molecules with Two Carbon Atoms

Angles B(1)–B(2)–B(7) B(1)–B(2)–C(6) B(7)–B(2)–C(6) Y…X…B(5) e Y…B(5)–H e B(3)–B(2)–H B(3)–B(7)–Hʹ B(3)–B(8)–Hʹ B(8)–B(7)–Hʹʹ H′–C(6)–H′′ B(2)–C(6)–H′

θh1 [deg] a

Dihedral angles B(1)–B(2)–B(7)–Hʹʹ B(1)–B(2)–C(6)–H′

τh1 [deg] a

109.2(2) d 107.1(3) d 63.8(4) d 100.4(5) d 130.1(20) d,f 123.8(2) d,f 123.1(6) d,f 120.1(4) d,f 44.6(3) d,f 111.7(8) d,f 111.2(3) d,f

35.8(11) d,f 149.7(7) d,f

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Differences between the B–B and B–C bond lengths were flexibly restrained to the values from MP2_full/6311++G(d,p) computation. c Differences between the B–H and C–H bond lengths were flexibly restrained to the values from computation as indicated above. d Independent parameter. e X refers to the midpoint of B(1)–B(2), Y refers to the midpoint of B(7)...B(9). f Flexibly restrained to the value from computation as indicated above. b

The GED experiment was carried out at Tnozzle of 388 and 403 K at the long and short nozzle-to-film distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311+G(d,p) computation. Wann DA, Lane PD, Robertson HE, Holub J, Hnyk D (2013) Structures of, and related consequences of deprotonation on, two Cs-symmetric arachno nine-vertex heteroboranes, 4,6-X2B7H9 (X = CH2; S) studied by gas electron diffraction/quantum chemical calculations and GIAO/NMR. Inorg Chem 52 (8):4502-4508

374 CAS RN: 460-19-5 MGD RN: 950201 IR

Ethanedinitrile Cyanogen C 2N 2 D∞ h N

Bonds C–C C≡N

C

C

N

re [Å] a 1.38109(60) 1.15976(40)

Copyright 2011 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit.

The rotationally resolved IR spectrum of cyanogen was recorded for the main isotopic species at room temperature by an FTIR spectrometer in the spectral region between 500 and 4900 cm-1. Many combination

4 Molecules with Two Carbon Atoms

295

bands with both degenerate fundamentals ν4 and ν5 as well as the effects of vibrational and rotational ℓ-type resonance were investigated. Together with previously published measurements below 500 cm-1 and earlier work on the two symmetric isotopic species 13C214N2 and 12C215N2 precise equilibrium rotational and rotation-vibration interaction constants were obtained taking into account higher-order interactions. From these parameters the experimental equilibrium structure was determined. Maki AG (2011) High-resolution infrared spectrum of cyanogen. J Mol Spectrosc 269(2):166-174

375 CAS RN: 627-52-1 MGD RN: 808269 MW, IR, augmented by ab initio calculations

Sulfur dicyanide

S C

C 2N 2S C2v C

N

Bonds S–C C≡N

r0 [Å] a 1.698(6) 1.160(9)

rs [Å] a 1.701(5) 1.158(6)

r e [Å] a 1.6972(4) 1.1602(4)

Bond angles C–S–C S–C≡N

θ0 [deg] a

θs [deg] a

98.6(5) 175.4(11)

98.2(3) 175.0(6)

θ see [deg] a

N

se

98.36(3) 175.14(5)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotationally resolved far-IR spectrum of sulfur dicyanide was recorded by FTIR spectroscopy in the region of the three fundamentals ν4, ν7, and ν8 as well as in the hot-band sequence of ν4, using synchrotron radiation as a very intense light source between 50 and 350 cm-1. The global analysis of pure rotation and rotation-vibration transitions allowed the determination of precise energies for twelve of the lowest vibrationally excited states se including the five lowest fundamentals. The semiexperimental equilibrium structure r e was derived taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the CCSD(T)/aug-cc-pVTZ harmonic and anharmonic (cubic) force fields. Kisiel Z, Winnewisser M, Winnewisser BP, DeLucia FC, Tokaryk DW, Billinghurst BE (2013) Far-infrared spectrum of S(CN)2 measured with synchrotron radiation: global analysis of the available high-resolution spectroscopic data. J Phys Chem A 117(50):13815-13824

376 CAS RN: 76939-96-3 MGD RN: 155254 IR

Carbon disulfide – carbonyl sulfide (1/1) C2OS3 Cs S

Distance Rcm b

r0 [Å] a 3.5553(8)

Angle

θ0 [deg] a

C

S

O

C

S

296

4 Molecules with Two Carbon Atoms

C(1)…C(2)=S(2)

104.82(22)

Reprinted with permission. Copyright 2010 American Chemical Society. a b

Parenthesized uncertainty in units of the last significant digit. Distance between the centers of mass of both monomer subunits.

The rotationally resolved IR spectrum of the binary complex of carbon disulfide with carbonyl sulfide was recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the stretching region ν1 of carbonyl sulfide at 2058 cm-1. Two bands were observed; one was assigned to the previously studied planar complex, where the second band was assigned to a new nonplanar cross-shaped form. An isotopically enriched 18OCS sample was also studied. The partial r0 structure was determined from the six ground-state rotational constants of both isotopic species assuming the orthogonal orientation of the CS2 subunit and unchanged subunit geometries. Norooz Oliaee J, Mivehvar F, Dehghany M, Moazzen-Ahmadi N (2010) Geometric isomerism in the OCS-CS2 complex: Observation of a cross-shaped isomer. J Phys Chem A 114(27):7311-7314

377 CAS RN: 139167-40-1 MGD RN: 126105 IR

Carbon dioxide – carbon monoxide (1/1) C 2O 3 C2v O

Distance Rcm b

r0 [Å] 3.583

C

O

C

O

a

Reproduced with permission of AIP Publishing.

a b

Uncertainty was not given in the original paper. Distance between the centers of mass of the monomer subunits.

The rotationally resolved IR spectrum of the title complex was recorded in a supersonic jet by a pulsed quantum cascade laser spectrometer in the region of the carbon monoxide stretching fundamental at about 2150 cm-1. The previously unobserved O-bonded T-shaped form was investigated. The partial r0 structure was determined from the ground-state rotational constants under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Sheybani-Deloui S, Barclay AJ, Michaelian KH, McKellar ARW, Moazzen-Ahmadi N (2015) Spectroscopic observation of the O-bonded T-shaped isomer of the CO-CO2 dimer and two of its intermolecular frequencies. J Chem Phys 143(12):121101/1-121101/4 [http://dx.doi.org/10.1063/1.4932043]

378 CAS RN: 1178880-53-9 MGD RN: 118885 IR

Carbon dioxide – carbonyl sulfide (1/1) C 2O 3S Cs O

Distance Rcm b

O-interior r0 [Å] a 3.9862 (10)

S-interior r0 [Å] a 3.5545 (10)

C

O

O

C

S

4 Molecules with Two Carbon Atoms

Angles c

θ1 θ2 d

θ0 [deg] a

118.0 (44) 135.8 (24)

297

θ0 [deg] a

69.7 (34) 78.7 (25)

Reproduced with permission of AIP Publishing [a].

O-interior

S-interior

a

Parenthesized uncertainties in units of the last significant digit. Distance between centers of mass in both monomer subunits. c Angle between Rcm and the O=C=O axis (measured from the inner O end). d Angle between Rcm and the O=C=S axis (measured from the S end). b

The rotationally resolved IR spectra of the binary complex of carbon dioxide with carbonyl sulfide were recorded by a pulsed-jet tunable diode laser spectrometer in the region of the C=O stretching fundamental of carbonyl sulfide at about 2060 cm-1. Samples with isotopically enriched carbon dioxide (either 13C or 18O) were investigated. The molecule was found to exist in two distinct slipped near-parallel configurations. The partial r0 structure of each form was determined from the ground-state rotational constants of three isotopic species under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. a. Dehghany M, Norooz Oliaee J, Afshari M, Moazzen-Ahmadi N, McKellar ARW (2009) Infrared spectra of the OCS-CO2 complex: Observation of two distinct slipped near-parallel isomers. J Chem Phys 130(22):224310/1-224310/5 doi: 10.1063/1.3152743 MW

Distance Rcm b

O-interior r0 [Å] a 3.9816(16)

Angles

θ0 [deg] a

c

θ1 θ2 d

108.8(46) 140.7(46)

Reproduced with permission of AIP Publishing [b].

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Angle between Rcm and O=C=O (measured from the inner O end). d Angle between Rcm and the O=C=S subunit (measured from the S end). b

298

4 Molecules with Two Carbon Atoms

The rotational spectra of the binary complex were recorded in a pulsed supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 18 GHz. Only the O-interior isomer was detected. A sample with 13C isotopically enriched carbon dioxide was also studied. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. b. Sedo G, van Wijngaarden J (2009) Fourier transform microwave spectra of a “new” isomer of OCS-CO2. J Chem Phys 131(4) 044303/1-044303/5 doi: 10.1063/1.3186756

379 CAS RN: 154474-31-4 MGD RN: 209039 MW

Phosphinidyneethenylidene

C

Bonds C=C C=P

r0 [Å] a 1.291(2) 1.615(2)

rs [Å] a 1.288(3) 1.619(3)

C

C 2P C∞ v P

r m [Å] a 1.289(1) 1.621(1) (1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound (2Πr electronic ground state) were investigated by FTMW and millimeter/submillimeter-wave direct absorption techniques in the frequency region between 17 and 545 GHz. The transient species was produced by an AC discharge of red phosphorous or trichlorophosphine with acetylene or methane. (1) The r0, rs and mass-dependent r m structures were determined from the ground-state rotational constants of four isotopic species (main and three 13C). The multiple double bond structure was found to define the linear configuration, as opposed to other main group dicarbides with cyclic structure, for instance SiC2. Halfen DT, Sun M, Clouthier DJ, Ziurys LM (2009) The rotational spectrum of the CCP (X2Πr) radical and its 13 C isotopologues at microwave, millimeter, and submillimeter wavelengths. J Chem Phys 130(1):014305/1014305/11 doi: 10.1063/1.3043367

380 CAS RN: MGD RN: 216079 IR

Carbon disufide dimer C2S4 D2d S a

Distance C=C

r0 [Å] 3.539(7)

Angle C=C=S

θ0 [deg] a 90

Reproduced with permission of AIP Publishing.

C

S

2

4 Molecules with Two Carbon Atoms a

299

Parenthesized uncertainty in units of the last significant digit.

The rotationally resolved IR spectrum of the carbon disulfide dimer was recorded in a pulsed-supersonic jet by a tunable diode laser spectrometer in the region of the CS2 ν3 fundamental band at about 1535 cm-1. A fundamental band with the C=S asymmetric stretching and its combination band were analyzed. The partial r0 structure was determined from the ground-state rotational constants of the main isotopic species under the assumption that the structural parameters of the monomer subunit were not changed upon complexation. Rezaei M, Norooz Oliaee J, Moazzen-Ahmadi N, McKellar ARW (2011) Spectroscopic observation and structure of CS2 dimer. J Chem Phys 134(14):144306/1-144306/5 doi:10.1063/1.3578177

381 CAS RN: 884487-79-0 MGD RN: 359400 MW

[(1,2-η)-Ethyne-1,2-diyl]scandium Scandium dicarbide C2Sc C2v Sc

Bonds Sc–C C≡C

r0 [Å] a 2.057 1.259

Bond angle C–Sc–C

θ0 [Å] a 35.6

Copyright 2014 with permission from Elsevier.

a

Uncertainties were not given in the original paper.

The rotational spectrum of scandium dicarbide (2A1 electronic ground state) was recorded by a pulsed-jet FTMW spectrometer in the frequency range between 15 and 63 GHz. The transient species was produced by a DC discharge of methane together with laser-ablated scandium atoms. The r0 structure was determined from the ground-state rotational constants of the main isotopic species. The molecule was found to have a T-shaped structure. Min J, Halfen DT, Ziurys LM (2014) Fourier transform microwave/millimeter-wave spectroscopy of the ScC2 (X2A1) radical: A model system for endohedral metallofullerenes. Chem Phys Lett 609:70-75

382 CAS RN: 245094-05-7 MGD RN: 151267 MW

[(1,2-η)-Ethyne-1,2-diyl]yttrium Yttrium dicarbide C 2Y C2v Y

Bonds C–Y C≡C

r0 [Å] a 2.194(2) 1.264(2)

r m [Å] a 2.187(4) 1.270(4) (1)

300

Bond angle C–Y–C

4 Molecules with Two Carbon Atoms

θ0 [Å] a 33.5(1)

θ (1) [Å] a m 33.74(7)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of yttrium dicarbide (2A1 electronic ground state) was recorded by a pulsed-jet FTMW spectrometer in the frequency range between 10 and 57 GHz. The transient species was produced by a DC discharge of methane together with laser-ablated yttrium atoms. (1) The r0 and r m structures were determined from the ground-state rotational constants of three isotopic species 13 (main, C and 13C2). The molecule was found to have a T-shaped structure. Halfen DT, Min J, Ziurys LM (2013) The Fourier transform microwave spectrum of YC2 (X2A1) and its 13C isotopologues: Chemical insight into metal dicarbides. Chem Phys Lett. 555:31-37

4 References

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336 337 338 339 340 341 342 343 344 345 346

347 348 349 350

351 352 353

354 355

356

306

4 Molecules with Two Carbon Atoms

357

358 359

360 361 362

363 364

365 366 367 368

369

370 371 372 373

374 375

(a) Durig JR, Deeb H, Darkhalil ID, Klaassen JJ, Gounev TK, Ganguly A (2011) The r0 structural parameters, conformational stability, barriers to internal rotation, and vibrational assignments for trans and gauche ethanol. J Mol Struct 985(2-3):202-210 (b) See 294(b). See 294(b). (a) Vogt N, Demaison J, Rudolph HD (2014) Semiexperimental equilibrium structure of the oblate-top molecules dimethyl sulfoxide and cyclobutene. J Mol Spectrosc 297:11-15 (b) Feder W, Dreizler H, Rudolph HD, Typke V (1969) rs-Struktur von Dimethylsulfoxid im Vergleich zur r0-Struktur. Z Naturforsch A 24:266-278 (c) Kretschmer U (1995) The 33S nuclear quadrupole hyperfine coupling in the rotational spectrum of 33S dimethyl sulfoxide. Z Naturforsch A 50(7):666-668 Favero LB, Evangelisti L, Feng G, Spada L, Caminati W (2011) Conformation and internal motions of dimethyl sulfate: A microwave spectroscopy study. Chem Phys Lett 517(4-6):139143 Demaison J, Margulès L, Rudolph HD (2010) Accurate determination of an equilibrium structure in the presence of a small coordinate: The case of dimethyl sulfide. J Mol Struct 978(1-3) 229-233 Darkhalil ID, Nagels N, Herrebout WA, van der Veken BJ, Gurusinghe RM, Tubergen MJ, Durig JR (2014) Microwave spectra and conformational studies of ethylamine from temperature dependent Raman spectra of xenon solutions and ab initio calculations. J Mol Struct 1068:101-111 Panikar SS, Deodhar BS, Sawant DK, Klaassen JJ, Deng J, Durig JR (2013) Raman and infrared spectra, r0 structural parameters, and vibrational assignments of (CH3)2PX where X = H, CN, and Cl. Spectrochim Acta A 103:205-215 Durig JR, Panikar SS, Iwata T, Gounev TK (2010) Conformational stability of ethylenediamine from temperature dependent infrared spectra of liquid xenon solutions, r0 structural parameters, ab initio calculations, and vibrational assignments. J Mol Struct 984(13):58-67 Blanco S, Pinacho P, López JC (2016) Hydrogen-bond cooperativity in formamide2-water: A model for water-mediated interactions. Angew Chem 128(32):9477-9481; Angew Chem Int Ed 55(32):9331-9335 Durig JR, Panikar SS, Purohit SS, Pai TH, Kalasinsky VF (2013) Conformational stabilities from variable temperature Raman spectra, r0 structural parameters and vibrational assignments of 1,2-diphosphinoethane. J Mol Struct 1033:19-26 Giuliano BM, Favero LB, Maris A, Caminati W (2012) Shapes and internal dynamics of the 1:1 adducts of ammonia with trans and gauche ethanol: A rotational study. Chem Eur J 18(40):12759-12763 Aldridge S, Downs AJ, Tang CY, Parsons S, Clarke MC, Johnstone RDL, Robertson HE, Rankin DWH, Wann DA (2009) Structures and aggregation of the methylamine-borane molecules, MenH3-nN·BH3 (n=1-3), studied by X-ray diffraction, gas-phase electron diffraction, and quantum chemical calculations. J Am Chem Soc 131(6):2231-2243 Vishnevskiy YV, Tikhonov DS, Reuter CG, Mitzel NW, Hnyk D, Holub J, Wann DA, Lane PD, Berger RJF, Hayes SA (2015) Influence of antipodally coupled iodine and carbon atoms on the cage structure of 9,12-I2-closo-1,2-C2B10H10: An electron diffraction and computational study. Inorg Chem 54 (24):11868-11874 Samdal S, Møllendal H, Hnyk D, Holub J (2011) Microwave spectra and structures of 1,2(ortho)- and 1,7-(meta)-carborane, C2B10H12. J Phys Chem A 115(15):3380-3385 See 370. Wann DA, Lane PD, Robertson HE, Baše T, Hnyk D (2013) The gaseous structure of closo9,12-(SH)2-1,2-C2B10H10, a modifier of gold surfaces, as determined using electron diffraction and computational methods. Dalton Trans 42 (33):12015-12019 Wann DA, Lane PD, Robertson HE, Holub J, Hnyk D (2013) Structures of, and related consequences of deprotonation on, two Cs-symmetric arachno nine-vertex heteroboranes, 4,6X2B7H9 (X = CH2; S) studied by gas electron diffraction/quantum chemical calculations and GIAO/NMR. Inorg Chem 52 (8):4502-4508 Maki AG (2011) High-resolution infrared spectrum of cyanogen. J Mol Spectrosc 269(2):166174 Kisiel Z, Winnewisser M, Winnewisser BP, DeLucia FC, Tokaryk DW, Billinghurst BE (2013) Far-infrared spectrum of S(CN)2 measured with synchrotron radiation: global analysis of the available high-resolution spectroscopic data. J Phys Chem A 117(50):13815-13824

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Chapter 5. Molecules with Three Carbon Atoms

383 CAS RN: 12075-35-3 MGD RN: 328932 IR

1,2-Propadiene-1,3-diylidene Tricarbon C3 D∞h

Bond C–C

r0 [Å] a 1.27746(22)

rm [Å] a 1.28955(31)

C

C

C

re [Å] a 1.29471(5)

Reproduced with permission of AIP Publishing. a

Parenthesized uncertainty in units of the last significant digit.

The rotationally resolved vibration spectrum of tricarbon was recorded in a supersonic jet by a THz spectrometer in the frequency region between 1.8 and 1.9 THz. The sample was vaporized by laser ablation of a sintered carbon target; in order to investigate all 13C labeled isotopic species an enriched target was used. The rovibrational transitions of ν2 bending fundamental were analyzed. The r0 and mass-dependent rm structures were determined from the ground-state rotational constants of six isotopic species (main, two 13C, two 13C2 and 13C3). The equilibrium structure re was obtained using experimental rotation-vibration interaction constants of the ν2 bending mode. Breier AA, Büchling T, Schnierer R, Lutter V, Fuchs GW, Yamada KMT, Mookerjea B, Stutzki J, Giesen TF (2016) Lowest bending mode of 13C-substituted C3 and an experimentally derived structure. J Chem Phys 145(23):234302/1-234302/10 [http://dx.doi.org/10.1063/1.4971854] 384 CAS RN: 432-02-0 MGD RN: 302615 GED augmented by QC computations

Tris(trifluoromethyl)arsine C3AsF9 C3 CF3

Bonds As–C C–F C(1)–F(1) C(1)–F(2) C(1)–F(3)

re [Å] a 2.007(2) 1.333(5) b 1.337(3) c 1.337(3) c 1.326(3) c

Bond angles As–C–F C–As–C F(1)–C(1)–F(2) F(1)–C(1)–F(3) F(2)–C(1)–F(3)

θe [deg] a

Dihedral and other angles twist (CF3)e drop (CF3) f F(3)–C(1)–As–C(2)

τe [deg] a

As F3C

CF3

111.0(1) b 95.4(3) d 109(1) 107.4(6) 107.3(6) 21(1) 31.3(2) 69(1) d

© Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_5

309

310

5 Molecules with Three Carbon Atoms

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Average value. c Derived due to determined difference in the C−F bonds. d Dependent parameter. e Torsional angle of the CF3 group around the C−As bond, zero position for the C3v overall point-group symmetry. f Deviation of the AsC3 fragment from planarity: ∠[(C–As…C3 axis) – 90°]. b

The GED experiment was carried out at room temperature. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP/6-311G** harmonic and anharmonic force constants taking into account non-linear kinematic effects. Berger RJF, Mitzel NW (2010) Reinvestigation of the gas-phase structure of tris(trifluoromethyl)arsine. J Mol Struct 978 (1-3):205-208

385 CAS RN: 1327368-96-6 MGD RN: 365720 GED augmented by QC computations

3-Chloro-3,3-difluoro-2-oxopropanenitrile C3ClF2NO C1 (gauche) O Cl

a,b

Bonds C(2)=O C(1)–C(2) C(1)≡N C(2)–C(3) C(3)–Cl C(3)–F(1) C(3)–F(2)

re [Å] 1.200(2) 1 1.480(7) 1.168(2) 1 1.520(6) 1.754(4) 1.326(2) 2 1.341(2) 2

Bond angles O=C(2)–C(1) C(2)–C(1)≡N O=C(2)–C(3) C(1)–C(2)–C(3) C(2)–C(3)–Cl C(2)–C(3)–F(1) C(2)–C(3)–F(2) Cl–C(3)–F(1) Cl–C(3)–F(2) F(1)–C(3)–F(2)

θe [deg] a,b

Dihedral angle O=C(2)–C(3)–Cl

τe [deg]

rg [Å] 1.204(2) 1.489(7) 1.172(2) 1.534(6) 1.761(4) 1.333(2) 1.348(2)

121.8(10) 178.8 c 122.3(12) 115.9(15) d 108.9(6) 110.5(4) 3 109.7(4) 3 109.9(2) 4 109.1(2) 4 108.7(11)

110.0 c

Reprinted with permission. Copyright 2011 American Chemical Society.

a

C

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

F F

N

5 Molecules with Three Carbon Atoms

311

b

Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/cc-pVTZ computations. c Assumed at the value from computation as above. d Dependent parameter. Two conformers, gauche and syn, characterized by the synclinal and synperiplanar O=C(2)–C(3)–Cl dihedral angles, respectively, were predicted by various QC calculations (in the ratio gauche : syn = 85 :15 (in %) by CBS-QB3). The GED experiment was carried out at Tnozzle = 293 K. A small amount of the syn conformer could not be detected in the GED analysis. The large-amplitude torsion motion about the C(2)–C(3) bond was described by a dynamic model adopting PEF from MP2/cc-pVTZ computation. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP/6-31G(d) quadratic and cubic force constants taking into account non-linear kinematic effects. Ramos LA, Ulic SE, Romano RM, Tong SR, Ge MF, Vishnevskiy YV, Berger RJ, Mitzel NW, Beckers H, Willner H, Della Védova CO (2011) Chlorodifluoroacetyl cyanide, ClF2CC(O)CN: synthesis, structure, and spectroscopic characterization. Inorg Chem 50 (19):9650-9659

386 CAS RN: 1446015-21-9 MGD RN: 514279 GED augmented by QC computations

2-Chloro-2,2-difluoroacetyl isothiocyanate C3ClF2NOS C1 (gauche-syn) C1 (gauche-anti) O

S

Bonds O(1)=C(1) C(1)–N(3) C(1)–C(2) N(3)=C(4) C(4)=S C(2)–Cl C(2)–F(1) C(2)–F(2) Bond angles O(1)=C(1)–N(3) O(1)=C(1)–C(2) N(3)–C(1)–C(2) C(1)–N(3)=C(4) C(1)–C(2)–Cl C(1)–C(2)–F(1) C(1)–C(2)–F(2) N(3)=C(4)=S Cl–C(2)–F(1) Cl–C(2)–F(2) F(1)–C(2)–F(2) Dihedral angle

a,b

gauche-syn 1.199(2) 1 1.399(7) 2 1.535(2) 3 1.213(2) 1 1.559(2) 3 1.767(4) 4 1.330(2) 5 1.343(2) 5

re [Å] gauche-anti 1.196(2) 1 1.396(7) 2 1.545(2) 3 1.213(2) 1 1.559(2) 3 1.768(4) 4 1.328(2) 5 1.346(2) 5

a

rg [Å] gauche-syn gauche-anti 1.203(2) 1.200(2) 1.407(7) 1.404(7) 1.547(2) 1.556(2) 1.217(2) 1.217(2) 1.566(2) 1.566(2) 1.774(4) 1.775(4) 1.338(2) 1.336(2) 1.350(2) 1.352(2)

Cl

C N F

F

θe [Å] a,b

gauche-syn 125.9(7) 6 121.3(10) 7 112.7(13) c 134.7(13) 8 109.1(2) 9 110.1(2) 9 110.1(2) 9 175.0 d 109.4(2) 10 109.0(2) 10 109.0(8) c

gauche-syn O(1)=C(1)–C(2)–Cl 100.0(88)

gauche-anti 124.4(7) 6 120.7(10) 7 114.9(13) c 135.3(13) 8 109.5(2) 9 110.2(2) 9 109.8(2) 9 174.7 d 109.5(2) 10 108.8(2) 10 109.0(8) c

τe [deg] a

gauche-anti 115.2(48)

gauche-syn

312

5 Molecules with Three Carbon Atoms

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with the equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from MP2_full/cc-pVTZ computations. c Dependent parameter. d Assumed at the value from computation as indicated above. b

gauche-anti

The GED experiment was carried out at Tnozzle = 293 K. The model of two conformers, gauche-syn and gaucheanti, was used in the GED analysis. These conformers, characterized by the synperiplanar and antiperiplanar O(1)=C(1)–N–C dihedral angles, respectively, possess the anticlinal O(1)=C(1)–C(2)–Cl chain. The ratio of the conformers was determined to be gauche-syn : gauche-anti = 42(10) : 58(10) (in %). Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from the B3LYP/6-31G(d) quadratic and cubic force constants taking into account non-linear kinematic effects. Ramos LA, Ulic SE, Romano RM, Vishnevskiy YV, Mitzel NW, Beckers H, Willner H, Tong SR, Ge MF, Della Védova CO (2013) Chlorodifluoroacetyl isothiocyanate, ClF2CC(O)NCS: Preparation and structural and spectroscopic studies. J Phys Chem A 117 (27):5597-5606

387 CAS RN: 1403964-33-9 MGD RN: 383644 GED augmented by QC computations

2-Chloro-2,2-difluoroacetyl isocyanate C3ClF2NO2 C1 (gauche-syn) C1 (gauche-anti) O O F

Bonds O(6)=C(1) C(1)–N(3) C(1)–C(2) N(3)=C(4) C(4)=O(5) C(2)–Cl(7) C(2)–F(8) C(2)–F(9) Bond angles O(6)=C(1)–N(3) O(6)=C(1)–C(2) N(3)–C(1)–C(2) C(1)–N(3)=C(4) C(1)–C(2)–Cl(7) C(1)–C(2)–F(8) C(1)–C(2)–F(9) N(3)=C(4)=O(5) Cl(7)–C(2)–F(8) Cl(7)–C(2)–F(9) F(8)–C(2)–F(9) Dihedral angle

re [Å] a,b gauche-syn 1.195(1)1 1.378(9)2 1.541(7) 3 1.218(1) 1 1.157(1) 1 1.756(4) 4 1.331(3) 5 1.343(3) 5

rg [Å] a 1.200(1) 1.388(9) 1.553(7) 1.223(1) 1.162(1) 1.764(4) 1.340(3) 1.351(3)

θe [deg] a,b

gauche-syn 124.8(8) 6 122.9(14) 7 112.3(16) c 128.6(19) 8 109.3(8) 9 109.8(5) 10 110.0(5) 10 173.1 d 110.0(3) 11 109.7(3) 11 108.1(15) 12

re [Å] a,b gauche-anti 1.192(1) 1.374(9) 2 1.548(7) 3 1.216(1) 1 1.158(1) 1 1.758(4) 4 1.327(3) 5 1.349(3) 5

rg [Å] a

C N

Cl

F

1.197(1) 1.384(9) 1.561(7) 1.221(1) 1.164(1) 1.767(4) 1.336(3) 1.356(3) gauche-anti

gauche-anti 121.8(8) 6 122.1(14) 7 116.1(16) c 131.9(19) 8 109.5(8) 9 110.2(5) 10 109.6(5) 10 172.5 d 110.2(3) 11 109.1(3) 11 108.1(15) 13

τe [deg] a

gauche-syn

5 Molecules with Three Carbon Atoms

O(6)=C(1)–C(2)–Cl(7)

gauche-syn 100.6(42)

313

gauche-anti 127.2(91)

Reprinted with permission. Copyright 2012 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from MP2_full/aug-cc-pVTZ computation. c Dependent parameter. d Fixed at the value from computation as indicated above. b

The GED experiment was carried out at Tnozzle = 293 K. The title compound was found to exist as a mixture of two conformers, gauche-syn and gauche-anti, characterized by the synperiplanar and antiperiplanar O(6)=C(1)– N(3)=C(4) dihedral angles, respectively; the O(6)=C(1)–C(2)–Cl(7) torsional angle is anticlinal one in each conformer. The ratio of the conformers was determined to be gauche-syn : gauche-anti = 72(7) : 28(7) (in %). Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from the B3LYP/6-31G(d) quadratic and cubic force constants taking into account non-linear kinematic effects. Ramos LA, Ulic SE, Romano RM, Vishnevskiy YV, Berger RJF, Mitzel NW, Beckers H, Willner H, Tong SR, Ge MF, Della Védova CO (2012) Chlorodifluoroacetyl isocyanate, ClF2CC(O)NCO: Preparation and structural and spectroscopic studies. J Phys Chem A 116 (47):11586-11595 388 CAS RN: 422-59-3 MGD RN: 213410 MW supported by DFT calculations

Bond C–Cl

2,2,3,3,3-Pentafluoropropanoyl chloride Perfluoropropionyl chloride C3ClF5O Cs F

O

F

Cl

F

rs [Å] a 1.777(3)

F

F

Reprinted with permission. Copyright 2010 American Chemical Society

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectra of the 35Cl and 37Cl isotopic species were recorded in natural abundance by a chirpedpulse FTMW spectrometer in the frequency region between 8 and 184 GHz. The partial rs structure was determined from the ground-state rotational constants of two isotopic species (main and 37Cl). Grubbs GS, Powoski RA, Jojola D, Cooke SA (2010) Some geometric and electronic structural effects of perfluorinating propionyl chloride. J Phys Chem A 114(30):8009-8015

389 CAS RN: 108-77-0 MGD RN: 931131 GED augmented by DFT computations

Bonds

rh1[Å] a

2,4,6-Trichloro-1,3,5-triazine C3Cl3N3 D3h

ra3,1 [Å] a

Cl

re,MD[Å] a N

Cl

N

N

Cl

314

5 Molecules with Three Carbon Atoms

C–Cl C–N

1.7116(9) 1.3287(6)

1.7045(9) 1.3214(6)

1.7024(9) 1.3214(6)

Bond angle N–C–N

θh1 [deg] a

θa3,1 [deg] a

θe,MD [deg] a

127.01(9)

127.13(10)

127.04(9)

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit.

The GED experiment was carried out at Tnozzle = 408 K. Vibrational corrections to the experimental internuclear distances were calculated using three different approximations. In the first one, the ∆rh1 = ra − rh1 corrections were calculated from the B3LYP/6-311+G(d) harmonic force constants taking into account non-linear kinematic effects. In the second one, the ∆ra3,1 = ra − ra3,1 vibrational correction accounted additionally for the effect of dynamic anharmonicity. The third approximation was the path-integral MD simulation applied to estimate distance corrections ∆re,MD = ra − re,MD. The MD method was presented to be very useful for study very flexible molecules for which the force constant calculations are inaccurate. Wann DA, Zakharov AV, Reilly AM, McCaffrey PD, Rankin DWH (2009) Experimental equilibrium structures: Application of molecular dynamics simulations to vibrational corrections for gas electron diffraction. J Phys Chem A 113 (34):9511-9520

390 CAS RN: 422-61-7 MGD RN: 536352 GED augmented by QC computations

2,2,3,3,3-Pentafluoropropanoyl fluoride C3F6O C1 (gauche) Cs (anti) F

O

F

Bonds C(1)=O C(1)–F C–F b C(1)–C(2) C(2)–C(3) Bond angles C–C–C F–C=O C(2)–C(1)=O C(2)–C(1)–F C–C–F b F–C–F b Dihedral angle F–C(1)–C(2)–C(3)

re [Å] a,c gauche anti 1.178(5) 1.180(5) 1.324(1) 1.325(1) 1.324(1) 1.325(1) 1.536(3) d 1.533(3) d d 1.542(3) 1.540(3) d

rg [Å] a,c gauche anti 1.183(5) 1.184(5) 1.332(1) 1.332(1) 1.331(1) 1.332(1) 1.548(3) 1.546(3) 1.556(3) 1.553(3)

F

F F

F

θe [Å] a,c

gauche 112.4(9) 124.9(8) 124.0(21) 111.1(22) 109.1(1) 109.3(4)

gauche 76.2(62)

anti 113.2(9) 124.7(8) 125.4(21) 110.0(22) 109.1(1) 109.2(4)

τe [Å] a

anti 180.0 e

gauche

5 Molecules with Three Carbon Atoms

315

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Average. c Structural differences between the conformers were assumed at the values from MP2/cc-pVTZ calculation. d Difference between the C(1)–C(2) and C(2)–C(3) bond lengths was assumed at the value computed at the level of theory as indicated above. e Assumed. b

anti Under conditions of the GED experiment (Tnozzle =279 K), the title compound was found to exist as a mixture of two conformers, gauche (85(10)%) and anti (15(10)%), differing by the magnitude of the C(3)–C(2)–C(1)–F torsional angle. In contrast, the FTIR spectra gave no clear evidence for the presence of the anti conformer. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP/cc-pVTZ quadratic and cubic force constants taking into account non-linear kinematic effects. Berrueta Martínez Y, Reuter CG, Vishnevskiy YV, Bava YB, Lorena Picone A, Romano RM, Stammler HG, Neumann B, Mitzel NW, Della Védova CO (2016) Structural analysis of perfluoropropanoyl fluoride in the gas, liquid, and solid phases. J Phys Chem A 120 (15):2420-2430

391 CAS RN: 754-34-7 MGD RN: 211232 MW augmented by QC calculations

1,1,1,2,2,3,3-Heptafluoro-1-iodopropane 1-Iodoperfluoropropane C3F7I Cs F

F

F

Bonds C(1)–C(2) C(2)–C(3) C(1)–I C(1)–F(1) C(1)–F(2) C(2)–F(3) C(2)–F(4) C(3)–F(5) C(3)–F(6) C(3)–F(7)

rs/r0 [Å] a 1.5634(2) 1.5781(2) 2.134(11) b 1.3424 c 1.3428 c 1.3478 c 1.3474 c 1.3338 c 1.3339 c 1.3352 c

Bond angles C(1)–C(2)–C(3) C(2)–C(1)–I F(1)–C(1)–C(2) F(2)–C(1)–C(2) F(3)–C(2)–C(3) F(4)–C(2)–C(3) F(5)–C(3)–C(2) F(6)–C(3)–C(2) F(7)–C(3)–C(2)

θs/θ0 [deg] a

113.633(14) 110.8(8) b 109.25 c 109.25 c 107.15 c 107.15 c 110.80 c 110.80 c 108.31 c

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

I

F

F

F

F

316 b c

5 Molecules with Three Carbon Atoms

r0 value. Fixed to the scaled values from m05-2X/cc-VTZ calculations.

The rotational spectra of the title compound were recorded by chirped-pulse and cavity-based FTMW spectrometers in the 1-4 GHz and 8-18 GHz regions. Only one conformer, characterized by the antiperiplanar C–C–C–I torsional angle, was observed. The rs structure of the carbon skeleton was determined from the ground-state rotational constants of four isotopic species (main and three 13C); all dihedral angles were fixed to the scaled values from calculations as above. The obtained structural parameters were used in the fit of r0(C–I) and θ0(C–C–I). Dewberry CT, Grubbs GS, Cooke SA (2009) A molecule with small rotational constants containing an atom with a large nuclear quadrupole moment: The microwave spectrum of trans-1-iodoperfluoropropane. J Mol Spectrosc 257(1):66-73

392 CAS RN: 623903-52-6 MGD RN: 503032 IR augmented by ab initio calculations

Bonds C=Ge C=C

1,2-Propadiene-1,3-diylidenebisgermylene C3Ge2 D∞ h Ge

C

C

C

Ge

re [Å] a 1.7695(1) 1.2893 b

Reprinted with permission. Copyright 2015 American Chemical Society

a b

Parenthesized uncertainty in unit of the last significant digit. Assumed at the CCSD(T)/cc-pwCVQZ value.

The rotationally resolved vibration spectrum of the title compound was recorded in a supersonic jet by a tunable quantum cascade laser spectrometer in the region of the antisymmetric C=C stretching fundamental ν3 at 1932 cm-1. The partial equilibrium structure re was determined from the rotational constants of six isotopic species (main, 72Ge, 70Ge, 72Ge2, 72Ge/70Ge and 70Ge2) in the ground and first excited vibrational states. Thorwirth S, Lutter V, Javed AJ, Gauss J, Giesen TF (2016) Gas-phase spectroscopic detection and structural elucidation of carbon-rich group 14 binary clusters: Linear GeC3Ge. J Phys Chem A 120(2):254-259

393 CAS RN: MGD RN: 439306 MW supported by ab initio calculations

Trifluoroethene – carbon dioxide (1/1) Trifluoroethylene – carbon dioxide (1/1) C3HF3O2 Cs H

F O

a

Distances H(6)…O(9) F(5)…C(7) Rcm b

r0 [Å] 2.754(34) 2.897(20) 4.5668(10)

Bond angles

θ0 [deg] a

F

F

C

O

5 Molecules with Three Carbon Atoms

C(4)–F(5)…C(7) F(5)…C(7)=O(9) C(7)=O(9)…H(6) O(9)…H(6)–C(4)

317

113.9(14) 82.5(8) 116.6(14) 110.0(14)

Reprinted with permission. Copyright 2016 American Chemical Society

a b

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits.

The rotational spectrum of the binary complex of trifluoroethene with carbon dioxide was recorded in a supersonic jet both by a chirped-pulse FTMW and a Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, two 18O and 18O2) assuming that the structural parameters of the monomer subunits were not changed upon complexation. Dorris RE, Trendell WC, Peebles RA, Peebles SA (2016) Rotational spectrum, structure, and interaction energy of the trifluoroethylene⋅⋅⋅carbon dioxide complex. J Phys Chem A 120(40):7865-7872

394 CAS RN: 1645-75-6 MGD RN: 428482 MW

1,1,1,3,3,3-Hexafluoro-2-propanimine Hexafluoroacetone imine C3HF6N C1 NH

Bonds C(1)–C(2) C(1)–C(3) C(1)=N

rs [Å] a 1.490(29) 1.486(2) 1.268(3)

Bond angles C(2)–C(1)–C(3) N=C(1)–C(2) N=C(1)–C(3)

θs [deg] a

Dihedral angle C(2)–C(1)=N–C(3)

τs [deg] a

F

F

F

F

F

F

120.5(19) 117.5(22) 121.9(11)

177.5(116)

Reprinted with permission. Copyright 2015 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit.

The partial rs structure was determined from the previously published ground-state rotational constants. Shahi A, Arunan E (2015) Microwave spectrum of hexafluoroisopropanol and torsional behavior of molecules with a CF3–C–CF3 group. J Phys Chem A 119(22):5650-5657

318

5 Molecules with Three Carbon Atoms

395 CAS RN: 16165-40-5 MGD RN: 102408 MW augmented by ab initio calculations

2-Cyclopropen-1-ylidene C 3H 2 C2v C

Bonds C(1)–C(2) C(1)–H

r see [Å] a 1.4172(1) 1.0751(2)

Bond angles C(1)–C(2)–C(1) H–C(1)–C(2)

θ see [deg] a

H

H

55.60(1) 147.78(3)

© AAS. Reproduced with permission. Published 2012 April 23.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of 2-cyclopropen-1-ylidene were recorded both by a molecular-beam Balle-Flygare type FTMW spectrometer in the frequency region between 10 and 43 GHz and by a millimeter-wave absorption spectrometer in the region between 85 and 453 GHz. The transient species were produced by a DC discharge of allene. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants of eight isotopic species (main, three 13C, D, two D2 and 13C/D) by taking into account rovibrational corrections calculated from the CCSD(T)_ae/cc-pwCVQZ harmonic and anharmonic (cubic) force fields. Spezzano S, Tamassia F, Thorwirth S, Thaddeus P, Gottlieb CA, McCarthy MC (2012) A high-resolution isotopic study of the rotational spectrum of c-C3H2. Astrophys J Suppl Series 200(1):1/1-1/11 doi:10.1088/0067-0049/200/1/1

396 CAS RN: MGD RN: 543552 MW supported by ab initio calculations

2,3,3,3-Tetrafluoro-1-propene – argon (1/1) 2,3,3,3-Tetrafluoro-1-propylene – argon (1/1) C3H2ArF4 C1 F

F

Distances Rcm b Ar…C(2) Ar…F(1) Ar…F(3)

a

r0 [Å] 3.9185 3.6592 3.4615 3.5358

F

H

F

Ar

H

Copyright 2017 with permission from Elsevier. a b

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of the tetrafluoropropene subunit.

The rotational spectrum of the binary van der Waals complex of 2,3,3,3-tetrafluoro-1-propene with argon was recorded by broadband chirped-pulse and narrow-band Balle-Flygare type FTMW spectrometers in the frequency region between 5.6 and 18.4 GHz.

5 Molecules with Three Carbon Atoms

319

The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main and three 13C) assuming that the tetrafluoropropene subunit was not changed upon complexation. The argon atom was found to be located out of the symmetry plane of the tetrafluoropropene subunit. Leung HO, Marshall MD, Wronkovich MA (2017) The microwave spectrum and molecular structure of Ar2,3,3,3-tetrafluoropropene. J Mol Spectrosc 337(1):80-85

397

2-Chloro-1-(difluoromethoxy)-1,1,2-trifluoroethane 2-Chloro-1,1,2-trifluoroethyl difluoromethyl ether Enflurane

CAS RN: 13838-16-9

MGD RN: 141631 MW augmented by QC calculations

C3H2ClF5O C1

F

Bond angles C(1)–C(2)–O C(2)–O–C(3) Cl–C(1)–C(2)

θ0 [Å]

Dihedral angles Cl–C(1)–C(2)–O C(1)–C(2)–O–C(3)

θ0 [deg]a

F

O Cl

111.1(1) 116.8(4) 113.5(3)

F

F

F

63(1) -172.4(5)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded by a Balle-Flygare type FTMW spectrometer in the frequency range between 8 and 26 GHz and by a chirped-pulse broadband spectrometer in the range from 2 to 18 GHz. Three conformers, sharing a common antiperiplanar C–C–O–C skeleton but differing in the orientations of the terminal chlorine and hydrogen atoms (synclinal or antiperiplanar), were observed in equimolar ratio. Only one of two conformations with ±synclinal Cl-C-C-O chains was experimental observable due to collisional relaxation in the jet. The partial r0 structure of this conformer was obtained from the ground–state rotational constants of five isotopic species (main, 37Cl and three 13C); the remaining structural parameters were assumed at the values from MP2/6311++G(2df,p) calculations. Pérez C, Caballero-Mancebo E, Lesarri A, Cocinero EJ, Alkorta I, Suenram RD, Grabow JU, Pate BH (2016) The conformational map of volatile anesthetics: enflurane revisited. Chem Eur J 22(28):9804-9811

398 CAS RN: 26675-46-7 MGD RN: 143507 MW augmented by ab initio calculations

2-Chloro-2-(difluoromethoxy)-1,1,1-trifluoroethane Isoflurane C3H2ClF5O C1 F

F

Bond angles C(1)–C(2)–O C(2)–O–C(3)

anti-anti θ0 [deg] a 106.7(10) 116.7(4)

anti-gauche θ0 [deg] a 107.8(10)

F

O F F

Cl

320

5 Molecules with Three Carbon Atoms

Cl–C(2)–O

112.5(10)

Dihedral angles C(1)–C(2)–O–C(3) Cl–C(2)–O–C(3)

θ0 [deg] a

137.8(11) -101.5(11)

113.9(8)

θ0 [deg] a

167.4(19) -69.8(14)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

anti-anti

anti-gauche

The rotational spectra of isoflurane were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 8 and 26 GHz. Two conformers characterized by the antiperiplanar carbon skeleton and different orientations of the difluoromethyl group, i.e. by antiperiplanar and synclinal H–C–O–C torsional angles. For the most stable conformer (anti-anti), four isotopic species (main, 37 Cl and two 13C) were investigated, whereas only two isotopic species (main and 37Cl) were studied for the second lowest-energy conformer (anti-gauche). The r0 structures were determined for the heavy-atom skeletons; the positions of the F and H atoms were constrained according to results of MP2/6-311++G(2df,p) calculations. Lesarri A, Vega-Toribio A, Suenram RD, Brugh DJ, Nori-Shargh D, Boggs JE, Grabow JU (2011) Structural evidence of anomeric effects in the anesthetic isoflurane. Phys Chem Chem Phys 13(14):6610-6618

399 CAS RN: 17341-93-4 MGD RN: 536708 GED augmented by QC computations

Bonds C(3)–Cl(1) C(3)=O(2) C(3)–O(3) O(3)–C(1) C(1)–C(2) C(2)–Cl C(1)–H

re [Å] a 1.744(2) b 1.184(8) 1.327(9) 1.422(10) 1.535(10) 1.772(2) b 1.090(15) c

Bond angles O(2)=C(3)–Cl(1) O(2)=C(3)–O(3) Cl(1)–C(3)–O(3)

θe [deg] a

124.9(17) 126.2(9) d 108.9(14)

2,2,2-Trichloroethyl chloroformate C3H2Cl4O2 Cs (anti-anti) C1 (anti-gauche) O

Cl Cl

O Cl Cl

5 Molecules with Three Carbon Atoms

C(3)–O(3)–C(1) O(3)–C(1)–C(2) Cl–C(2)–Cl

110.6(23) 105.1(10) 109.2(9)

Dihedral angles Cl(1)–C(3)–O(3)–C(1) C(3)–O(3)–C(1)–C(2)

τe [deg] a

321

179.1(24) 180.0 e

Reproduced with permission from the PCCP Owner Societies.

anti-anti

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Difference between the C(3)–Cl(1) and C(2)–Cl bond lengths was fixed at the value from MP2/6-311G(d,p) calculation. c Average value. d Dependent parameter. e Fixed. b

Two conformers of the title compound, anti-anti and anti-gauche, characterized by the antiperiplanar Cl(1)– C(3)–O(3)–C(1) dihedral angles and differing in the C(3)–O(3)–C(1)–C(2) torsional angles (antiperiplanar and anticlinal, respectively), with an energy difference of 1.5 kJ mol-1 were predicted by B3LYP/6-311++G(d,p) computations. The amount of the most stable Cs conformer was estimated to be 48 % (at room temperature). IR and Raman vibrational spectra provided evidence for the presence of both conformers. The GED experiment was carried out at Tnozzle = 328 K. The experimental data were analyzed using dynamic model based on the PEF from MP2/6-311G(d,p) calculations. The GED analysis proved the existence of both conformers. However, due to the low height of the PES profile, the ratio of the conformers could not be determined. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using the quadratic and cubic force constants from ab initio computation at the level of theory as indicated above as well as taking into account non-linear kinematic effects. Structural parameters were presented for the anti-anti conformer. Gil DM, Tuttolomondo ME, Blomeyer S, Reuter CG, Mitzel NW, Ben Altabef A (2016) Gas-phase structure of 2,2,2-trichloroethyl chloroformate studied by electron diffraction and quantum-chemical calculations. Phys Chem Chem Phys 18 (1):393-402

400 CAS RN: 1850243-00-3 MGD RN: 439724 MW supported by ab initio calculations

1,1-Difluoroethene – carbon dioxide (1/1) 1,1-Difluoroethylene – carbon dioxide (1/1) C3H2F2O2 Cs H

F O

Distances C(5)…C(6) Rcm b O(1)…H(8) c C(5)…F(10) c

r0 [Å] a 3.9130(37) 3.9181(2) 2.706(48) 2.953(17)

Angles C(6)…C(5)=O(4) C(7)=C(6)…C(5) C(7)–H(8)…O(1) c C(5)=O(1)…H(8) c

θ0 [deg] a

106.61(12) 89.2(16) 136.5(21) 121.9(6)

H

F

C

O

322

5 Molecules with Three Carbon Atoms

Reprinted with permission. Copyright 2016 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Dependent parameter. b

The rotational spectra of the binary complex of 1,1-difluoroethene with carbon dioxide were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5.5 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, three 13C and 18O2) under the assumption that the structural parameters were not changed upon complexation. Anderton AM, Peebles RA, Peebles SA (2016) Rotational spectrum and structure of the 1,1difluoroethylene⋅⋅⋅carbon dioxide complex. J Phys Chem A 120(2):247-253

401 CAS RN: 754-12-1 MGD RN: 137457 MW augmented by ab initio calculations

2,3,3,3-Tetrafluoro-1-propene 2,3,3,3-Tetrafluoropropylene C3H2F4 Cs F

F

Distances C(1)=C(2) C(2)–C(3) C(2)–F(1) C(3)–F(2) C(3)–F(3) C(3)–F(4)

r e [Å] a 1.3215 b 1.5029 c 1.332349(35) 1.330641(4) 1.333291(4) 1.333291(4)

Bond angles C(3)–C(2)=C(1) F(2)–C(3)–C(2)

θ see [deg] a

H

se

F

F

H

126.0415(87) 111.0164(15)

Copyright 2011 with permission from Elsevier [a]. a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Fixed to the value determined by the Kraitchman analysis. c Calculated from the Kraitchman coordinates by assuming that the C(3) atom lies on the a axis. b

The rotational spectrum of the title compound was recorded by a chirped-pulse FTMW spectrometer in the spectral region between 6 and 18 GHz. Three singly substituted 13C isotopic species were investigated in natural abundance. No evidence of any splittings or extra transitions reflecting the internal rotation of the terminal CF3 group was observed. se The partial r e structure was determined from the ground-state rotational constants taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated from the MP2/6-311++G(2d,2p) harmonic and anharmonic (cubic) force fields. a. Marshall MD, Leung HO, Scheetz BQ, Thaler JE, Muenter JS (2011) A chirped pulse Fourier transform microwave study of the refrigerant alternative 2,3,3,3-tetrafluoropropene. J Mol Spectrosc 266(1):37-42

5 Molecules with Three Carbon Atoms

323

MW augmented by ab initio calculations

Bonds C(2)–F(1) C(3)–F(2) C(3)–F(3) C(1)=C(2) C(2)–C(3) C(1)–H(1) C(1)–H(2)

r0 [Å] a 1.34655(55) 1.335659(62) 1.338309(62) 1.3215 b 1.5029 b 1.0766 c 1.0747 c

Bond angles C(1)=C(2)–C(3) C(2)–C(3)–F(2) C(2)–C(3)–F(3) C(2)=C(1)–H(1) C(2)=C(1)–H(2) C(1)=C(2)–F(1)

θ0 [deg] a

Dihedral angle C(1)=C(2)–C(3)–F(3)

τ0 [deg]

126.84(13) 111.858(22) 110.865 c 120.140 c 119.396 c 122.770 c

120.366 c

Copyright 2017 with permission from Elsevier [b].

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Fixed to the value of previously determined structure. c Adopted from MP2/6-311++G(2d,2p) calculation. b

The r0 structure was determined from the previously published rotational constants of four isotopic species. b. Leung HO, Marshall MD, Wronkovich MA (2017) The microwave spectrum and molecular structure of Ar2,3,3,3-tetrafluoropropene. J Mol Spectrosc 337(1):80-85

402 CAS RN: 920-66-1 MGD RN: 151520 MW supported by ab initio calculations

1,1,1,3,3,3-Hexafluoro-2-propanol Hexafluoroisopropanol C3H2F6O C1 OH

F

F

a

Bonds C(1)–C(2) C(2)–C(3) C(2)–H(1) C(2)...H(2) db

rs [Å] 1.530(7) 1.530(7) 1.121(3) 1.935(3) 2.119(1)

Bond angles C(1)–C(2)–C(3) H(1)–C(2)–C(1) H(1)–C(2)–C(3)

θs [deg] a 113.2(6) 103.9(7) 113.2(7)

F

F

F

F

324

5 Molecules with Three Carbon Atoms

H(1)–C(2)…H(2)

137.4(3)

Dihedral angles C(1)–C(2)–H(1)–C(3) C(3)–C(2)…H(2)–C(1)

τs [deg] a 123.2(8) 113.5(5)

Reprinted with permission. Copyright 2015 American Chemical Society

a b

Parenthesized uncertainties in units of the last significant digit. Distance between the H(2) atom and the center-of-mass.

The rotational spectrum of hexafluoroisopropanol was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 3 and 16 GHz. The observed spectrum was assigned to the most stable conformer, characterized by the antiperiplanar H‒O‒C‒H fragment, predicted by MP2/6-311++G(d,p) calculations. The partial rs structure was determined from the ground-state rotational constants of five isotopic species (main, two 13C, D and D2). Shahi A, Arunan E (2015) Microwave spectrum of hexafluoroisopropanol and torsional behavior of molecules with a CF3–C–CF3 group. J Phys Chem A 119(22):5650-5657

403 CAS RN: 1342884-78-9 MGD RN: 215126 MW supported by ab initio calulations

Ethyne – bromodifluoromethane (1/1) Acetylene – bromodifluoromethane (1/1) C3H3BrF2 Cs Br

H

Distances X…C(2) b X…H(2) c H(1)…Br c Angles C(1)…X…C(2) b Br-C(2)…X C(1)…X…H(2) c X…H(2)-C(2) c

r0 [Å] a 3.683(7) 2.670(8) 3.293(40)

F

C

C

H

F

θ0 [deg] a 73.9(14) 91.7(4) 81.6(14) 153.2(5)

Reprinted with permission. Copyright 2011 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit. X is the midpoint of the C≡C bond. c Dependent parameter. b

The rotational spectra of the binary complex of ethyne with bromodifluoromethane were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 6 and 18 GHz. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 81Br, 13 C2 and 81Br/13C2) under the assumption that the structural parameters of the monomer subunit were not changed upon complexation. The complex is formed by two hydrogen bonds, one between the acetylenic H and the Br atom and the other one between the H atom in the bromodifluoromethane subunit and the π-electron system of the C≡C bond.

5 Molecules with Three Carbon Atoms

325

Obenchain DA, Bills BJ, Christenholz CL, Elmuti LF, Peebles RA, Peebles SA, Neill JL, Steber AL (2011) CH⋅⋅⋅π interactions in the CHBrF2⋅⋅⋅HCCH weakly bound dimer. J Phys Chem A 115(44):12228-12234

404 CAS RN: 1258606-85-7 MGD RN: 214326 MW supported by ab initio calculations

Ethyne – chlorodifluoromethane (1/1) Acetylene – chlorodifluoromethane (1/1) C3H3ClF2 Cs Cl

H a

Distances Rcm b d1 c d2 d

r0 [Å] 3.710(4) 2.730(6) 3.061(38)

Angles

θ0 [deg] a

e

ϕ φf

C

C

H F

F

69.1(13) 88.0(5)

Reproduced with permission from the PCCP Owner Societies [a].

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of two monomer subunits. c Distance between H and the midpoint of the C≡C bond. d Distance between Cl and H in the ethyne subunit. e Angle between Rcm and the C∞ axis of the ethyne subunit. f Angle between Rcm and the C–Cl bond. b

The rotational spectra of the binary complex of chlorodifluoromethane with ethyne were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 7 and 18 GHz. From the ground-state rotational constants of four isotopic species (main, 37Cl, 13C2 and 37Cl/13C2) the partial r0 structure was determined under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. a. Sexton JM, Elliott AA, Steber AL, Peebles SA, Peebles RA, Neill JL, Muckle MT, Pate BH (2010) Characterization of C-H⋅⋅⋅π interactions in the structure of the CHClF2-HCCH weakly bound complex. Phys Chem Chem Phys 12(42):14263-14270 MW supported by ab initio calculations

Cs

Distances X…C(2) b X…H(2) H(1)…Cl

rs [Å] a 3.7063(45) 2.724(7) 3.122(46)

Angles C(1)…X…C(2) b Cl–C(2)…X C(2)–H(2)…X

θs [deg] a 71.1(16) 88.3(5) 148.7(7)

326

Cl…H(1)–C(1)

5 Molecules with Three Carbon Atoms

112.0(19)

Reprinted with permission. Copyright 2011 American Chemical Society [b].

a b

Parenthesized uncertainties in units of the last significant digit. X is the midpoint of the C≡C bond.

The rs structure was determined from previously published rotational constants. The complex is formed by two hydrogen bonds, one between the acetylenic H and the Cl atom and the other one between the H atom in the chlorodifluoromethane subunit and the π-electron system of the C≡C bond. b. Obenchain DA, Bills BJ, Christenholz CL, Elmuti LF, Peebles RA, Peebles SA, Neill JL, Steber AL (2011) CH⋅⋅⋅π interactions in the CHBrF2⋅⋅⋅HCCH weakly bound dimer. J Phys Chem A 115(44):12228-12234

405 CAS RN: 5130-24-5 MGD RN: 133065 MW supported by ab initio calculation

Carbonochloridic acid ethenyl ester Vinyl chloroformate C3H3ClO2 Cs O

Bonds Cl–C(2) C(2)=O(3) C(2)–O(4) O(4)–C(5) C(5)=C(6)

rs [Å] a 1.754 1.196 1.312 1.402 1.330

Bond angles Cl–C(2)=O(3) Cl–C(2)–O(4) O(3)=C(2)–O(4) C(2)–O(4)–C(5) O(4)–C(5)=C(6)

θs [deg] a

Cl

O

CH2

122.0 108.6 129.3 115.7 118.6

Copyright 2012 with permission from Elsevier.

a

Uncertainties were not given in the original paper.

The rotational spectrum of the title compound was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 6 and 16 GHz. Only one conformer characterized by the synperiplanar O=C–O–C and antiperiplanar C–O–C=C dihedral angles was observed. The rs structure of the heavy-atom skeleton was determined from the ground-state rotational constants of seven isotopic species (main, 37Cl, three 13C and two 18O). This planar conformer was predicted to be the most stable one by MP2/6-311++G** calculation. Bimler J, Broadbent S, Utzat KA, Bohn RK, Restrepo A, Michels HH, True NS (2012) Microwave spectrum, molecular structure, and quadrupole coupling of vinyl chloroformate. J Mol Struct 1023:87-89

5 Molecules with Three Carbon Atoms

327

406 CAS RN: 1624363-32-1 MGD RN: 430938 MW supported by ab initio calculations

Fluoroethene – carbon dioxide (1/1) Vinyl fluoride – carbon dioxide (1/1) C3H3FO2 Cs (I) Cs (II) H

F O

H

Distances C(2)…C(7) Rcm b O(3)…H(9) C(2)...F(8) O(1)...H(5) Angles C(7)…C(2)=O(3) C(4)=C(7)…C(2) C(7)–H(9)…O(3) C(2)=O(3)…H(9) C(4)–H(5)…O(1) C(2)=O(1)…H(5)

side-bonded (I) r0 [Å] a 3.632(10) 3.709(10) 2.58(10) c 2.935(10) c

top-bonded (II) r0 [Å] a 3.9216(6) 3.4573(2)

θ0 [deg] a

θ0 [deg] a

63.2(10) 170.0(20) 121.3(20) c 114.7(20) c

C

O

H

top-bonded (II) rs [Å] a 3.8925(17)

2.907(3) c 2.680(11) c 104.7(4) 86.64(25)

θs [deg] a 86.79(14)

137.2(3) c 119.9(3) c

Reprinted with permission. Copyright 2014 American Chemical Society a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Dependent parameter. b

side-bonded (I)

top-bonded (II)

The rotational spectra of the binary complex of vinyl fluoride with carbon dioxide were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 7 and 19 GHz. Two different structural conformations of the complex, I and II, were assigned. In one form the CO2 subunit is interacting with the CHF-side, whereas in the second one the CO2 subunit is interacting with the HC=CF side. For the side-bonded form a partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 13C), whereas for the top-bonded form the ground-state rotational constants of four isotopic species (main and three 13C) were used. Both structures were obtained under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The partial rs structure was determined for the top-bonded form. Christenholz CL, Dorris RE, Peebles RA, Peebles SA (2014) Characterization of two isomers of the vinyl fluoride⋅⋅⋅carbon dioxide dimer by rotational spectroscopy. J Phys Chem A 118(38):8765-8772 407 CAS RN: 421-50-1 MGD RN: 833242 MW augmented by ab initio calculations

1,1,1-Trifluoro-2-propanone 1,1,1-Trifluoroacetone C3H3F3O Cs

328

5 Molecules with Three Carbon Atoms

Bonds C(1)–C(2) C(2)–C(3) C(2)=O(4) C(3)–F(5) C(3)–F(6) C(1)–H(8) C(1)–H(9)

r0 [Å] a 1.505 b 1.531(1) 1.211 b 1.325 b 1.347 b 1.090 b 1.094 b

rs [Å] a 1.495(7) 1.521(4) 1.217(8)

Bond angles C(1)–C(2)–C(3) C(1)–C(2)=O(4) C(2)–C(3)–F(5) C(2)–C(3)–F(6) C(2)–C(1)–H(8) C(2)–C(1)–H(9)

θ0 [deg] a

θs [deg] a

116.8(1) 123.0(1) 112.5 b 109.5 b 109.2 b 109.3 b

O F CH3 F

F

116.6(6) 124.9(9)

Dihedral angles τ0 [deg] a O(4)=C(2)–C(3)–F(6) 121.3(1) O(4)=C(2)–C(1)–H(9) 121.6 b Copyright 2009 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Fixed to the value from MP2/6-311++G(d,p) calculations.

The rotational spectra of the title compound were recorded by a pulsed supersonic beam FTMW spectrometer in the spectral region between 6 and 18 GHz. The partial r0 and rs structures were obtained from the ground-state rotational constants of five isotopic species (main, three 13C and 18O). From the analysis of the tunneling splittings, the threefold barrier to internal rotation of the methyl group was determined to be 3.28 kJ mol-1. Evangelisti L, Favero LB, Maris A, Melandri S, Vega-Toribio A, Lesarri A, Caminati W (2010) Rotational spectrum of trifluoroacetone. J Mol Spectrosc 259(2):65-69

408 CAS RN: 431-47-0 MGD RN: 815501 GED combined with MW and augmented by QC computations

Trifluoroacetic acid methyl ester Methyl trifluoroacetate C3H3F3O2 Cs O F

Bonds C(1)–O(2) O(2)–C(3) C(3)–H(4) C(3)–H(5) C(3)–H(6) C(1)=O(7) C(1)–C(8) C(8)–F(9) C(8)–F(10)

a,b

re [Å] 1.326(6) 1.421(4) 1.083(14) 1 1.087(14) 1 1.087(14) 1 1.190(7) 1.533(4) 1.320(6) 2 1.320(6) 2

O F F

CH3

5 Molecules with Three Carbon Atoms

C(8)–F(11)

1.319(4)

Bond angles C(1)–O(2)–C(3) O(2)–C(3)–H(4) O(2)–C(3)–H(5) O(2)–C(3)–H(6) O(2)–C(1)=O(7) O(7)–C(1)–C(8) O(2)–C(1)–C(8) C(1)–C(8)–F(9) C(1)–C(8)–F(10) C(1)–C(8)–F(11)

θe [deg] a,b

329

116.3(5) 105.2 c 110.0 c 110.0 c 125.2(5) d 123.7 c 111.2(5) 110.1(3) 3 110.1(3) 3 110.1(3) 3

Dihedral angles C(1)–O(2)–C(3)–H(4) C(1)–O(2)–C(3)–H(5) C(1)–O(2)–C(3)–H(6) O(7)=C(1)–O(2)–C(3) C(8)–C(1)–O(2)–C(3) O(7)=C(1)–C(8)–F(9) O(7)=C(1)–C(8)–F(10) O(7)=C(1)–C(8)–F(11)

τe [deg] a

180.0 c -60.4 c 60.4 c 0.0 c 180.0 c 121.5(1) -121.5(1) d 0.0 c

Reprinted with permission. Copyright 2014 American Chemical Society [a]. a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/6-311++G(d,p) computation. c Fixed at the value from computation as indicated above. d Dependent parameter. b

The existence of two conformers, anti and syn (both with Cs point-group symmetry), with the C(3)–O(2)–C(1)– C(8) torsional angles of 180° and 0°, respectively, was predicted by MP2/cc-pVTZ computations. The barrier to rotation about the O(2)–C(1) bond was estimated to be 54 kJ mol-1. Both GED (Tnozzle = 294 K) and MW data revealed the presence of the anti conformer only. Vibrational corrections to the experimental rotational constants, ∆B = B0 – Be, and internuclear distances, ∆re = ra – re, were calculated from the MP2/6-31G(d,p) quadratic and cubic force constants taking into account nonlinear kinematic effects. In the GED analysis, the large-amplitude motion of the CF3 group was described by a dynamic model based on the following PEF: V(τ) = (V3/2)(1 – cos 3τ), where τ is rotational coordinate of the CF3 group. The barrier to rotation, V3, was determined to be 2.3(4) kJ mol-1. a. Kuze N, Ishikawa A, Kono M, Kobayashi T, Fuchisawa N, Tsuji T, Takeuchi H (2015) Molecular structure and internal rotation of CF3 group of methyl trifluoroacetate: Gas electron diffraction, microwave spectroscopy, and quantum chemical calculation studies. J Phys Chem A 119 (9):1774-1786 Cs (anti)

GED augmented by QC computations

Bonds r1 C(3)−H C(1)=O(7) C(1)−O(2)

rh1 [Å] a 1.3620(5) b 1.089(4) c,d 1.208(2) e 1.328(3) e

330

5 Molecules with Three Carbon Atoms

C(3)–O(2) C(1)−C(8) C(8)−F(9) C(8)−F(11)

1.444(3) e 1.544(2) e 1.341(2) e 1.329(3) e

Bond angles O−C−H H(5)−C(3)−H(6) C(1)−O(2)−C(3) O(2)−C(1)−C(8) F(9)−C(8)−F(11) C(8)−C(1)=O(7) O(2)–C(3)–H(5) O(2)–C(3)–H(4) C(1)–C(8)–F(9) C(1)–C(8)–F(11)

θh1 [deg] a

108.9(8) c,d 111.2(9) d 112.6(4) 110.3(4) 108.9(3) d 122.1(4) 111.2(8) e 106.6(8) e 111.0(2) f 111.0(3) f

Copyright © 2009 John Wiley & Sons, Ltd. Reproduced with permission [b].

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value of the C−F, C−O, C=O and C−F bond lengths; differences between these parameters were restrained to the values from MP2/6-311++G(d,p) computation. c Average value. d Restrained to the value from computation as indicated above. e Dependent parameter. f Difference between the C(1)–C(8)–F bond angles was restrained to the value from computation as indicated above. b

The GED experiment was carried out at room temperature (approximately 293 K). The title molecule was found to exist as a single conformer (anti) characterized by the antiperiplanar C−C−O−C torsional angle. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311++G(d,p) computation. According to predictions of MP2 and B3LYP computations (with various basis sets), the second conformer (syn), with the C−C−O−C torsional angle of 0°, is higher in energy by more than 30 kJ mol−1. Analysis of the total potential energy in terms of a Fourier-type expansion showed that the electrostatic and steric interactions are responsible for stabilizing the anti conformer, while the hyperconjugative effects stabilize both conformers. b. Defonsi Lestard ME, Tuttolomondo ME, Varetti EL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2009) Gas-phase structure and new vibrational study of methyl trifluoroacetate (CF3C(O)OCH3). J Raman Spectrosc 40 (12):2053-2062

409 CAS RN: 32042-38-9 MGD RN: 214399 MW supported by ab initio calculations

2,2,2-Trifluoroethanol 1-formate 2,2,2-Trifluoroethyl formate C3H3F3O2 O Cs F H

Bond C(2)–C(3)

rs [Å] a 1.487(5)

O F

F

5 Molecules with Three Carbon Atoms

Bond angle C(1)–C(2)–C(3)

331

θs [deg] a 135.4(6)

Reprinted with permission. Copyright 2011 American Chemical Society

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectra of 2,2,2-trifluoroethyl formate were recorded in a molecular beam by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region up to 18 GHz. The rs structure was determined for the carbon skeleton from the ground-state rotational constants of four isotopic species (main and three 13C). Evangelisti L, Grabowiecki A, van Wijngaarden J (2011) Chirped pulse Fourier transform microwave study of 2,2,2-trifluoroethyl formate. J Phys Chem A 115(30):8488-8492

410 CAS RN: 107-13-1 MGD RN: 711080 MW augmented by ab initio calculations

2-Propenenitrile Acrylonitrile C 3H 3N Cs H

H

Bonds C(1)=C(2) C(2)–C(3) C(3)≡N C(1)–H(1) C(1)–H(2) C(2)–H(3)

r0 [Å] a 1.342(2) 1.430(2) 1.164(2) 1.086(3) 1.089(9) 1.086(2)

rs [Å] a 1.344(4) 1.429(5) 1.160(5) 1.093(4) 1.097(17) 1.085(3)

r m [Å] a 1.3383(11) 1.4271(18) 1.1615(13) 1.0884(13) 1.0859(42) 1.0865(11)

r e [Å] a 1.3353(4) 1.4314(4) 1.1583(4) 1.0797(4) 1.0800(13) 1.0798(4)

Bond angles C(2)=C(1)–H(1) C(2)=C(1)–H(2) C(1)=C(2)–H(3) C(1)=C(2)–C(3) C(2)–C(3)≡N

θ0 [deg] a

θs [deg] a

120.6(1) 119.3(14) 122.0(1) 122.0(1) 180.4(5)

120.3(5) 118.5(18) 121.6(6) 122.0(6) 179.0(10)

θ (1) [deg] a m

θ see [deg] a

(1)

120.40(6) 119.81(64) 121.76(9) 122.33(16) 179.52(32)

C

se

N H

121.22(2) 120.28(21) 121.50(3) 122.03(6) 179.08(11)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded in the frequency region up to 1200 GHz using cascaded harmonic multiplication spectrometers. The ground-state rotational constants of six isotopic species (three 13C2, three 13C/15N) together with the previously published rotational constants of other isotopic species were used for the determinations of the r0, rs (1) se and r m structures. The semiexperimental equilibrium structure r e was obtained taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated from the CCSD(T)/cc-pVTZ harmonic and anharmonic (cubic) force fields.

332

5 Molecules with Three Carbon Atoms

Krasnicki A, Kisiel Z, Drouin BJ, Pearson JC (2011) Terahertz spectroscopy of isotopic acrylonitrile. J Mol Struct 1006(1-3):20-27

411 CAS RN: 631-57-2 MGD RN: 297780 MW augmented by ab initio calculations

2-Oxopropanenitrile Pyruvonitrile C3H3NO Cs O

Bonds C(2)=O(5) C(2)–C(3) C(1)–C(2) C(3)≡N(4) C(1)–H(6) C(1)–H(7)

r e [Å] a 1.2044(24) 1.4811(10) 1.4977(25) 1.1568(13) 1.0819(42) 1.0902(20)

Bond angles C(3)–C(2)=O(5) C(1)–C(2)=O(5) C(2)–C(3)–N(4) C(2)–C(1)–H(6) C(2)–C(1)–H(7)

θ see [deg] a

Dihedral angles O(5)=C(2)–C(1)–H(7) O(5)=C(2)–C(1)–H(8) C(3)–C(2)–C(1)–H(6) O(5)=C(2)–C(1)–H(6)

τ see [deg] a

se

H 3C

C N

119.40(39) 125.312(75) 177.37(76) 109.653(75) 109.236(35)

121.340(36) -121.340(36) 180.0 0.0

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

Using the previously published ground-state rotational constants of various isotopic species the se semiexperimental equilibrium structure r e was determined taking into account rovibrational corrections calculated with the MP2/aug-cc-pVTZ harmonic and anharmonic (cubic) force fields. Bellili A, Linguerri R, Hochlaf M, Puzzarini C (2015) Accurate structural and spectroscopic characterization of prebiotic molecules: The neutral and cationic acetyl cyanide and their related species. J Chem Phys 143(18):184314/1-184314/12 [http://dx.doi.org/10.1063/1.4935493]

412 CAS RN: 3998-25-2 MGD RN: 781911 MW supported by QC calculations

Acetyl isocyanate C3H3NO2 Cs (syn)

5 Molecules with Three Carbon Atoms

Bonds C(1)–C(2) C(1)–N(1) N(1)=C(3) C(3)=O(2) C(1)=O(1) C–H Bond angles O(1)=C(1)–N(1) O(1)=C(1)–C(2) C(2)–C(1)–N(1) C(1)–N(1)=C(3) N(1)=C(3)=O(2) C(1)–C(2)–H d C(1)–C(2)–H e

333

r0 [Å] a 1.504(5) 1.405(5) 1.2115 b 1.1750 b 1.192 b 1.090 b

O

O C H 3C

N

θ0 [deg] a

123.7(5) 125.0(4) 111.3(9) c 129.5(5) 178.6(7) 105.57 b 110.67 b

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Assumed at the value for hydrogen isocyanate or acetyl chloride taken from the literature. c Dependent parameter. d In-plane H. e Out-of-plane H. b

The rotational spectra of two isotopic species of acetyl isocyanate 13CH3C(O)NCO and CD3C(O)NCO (enriched samples) were recorded at room temperature by a Stark-modulated MW spectrometer in the spectral range between 26.5 and 40.0 GHz. Only one conformer, syn, with the s-cis configuration of the O=C-N=C fragment was observed. The molecular skeleton was found to be planar. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main, 13C and D3). The barrier to internal rotation of the 13CH3 group was determined to be 4.283(16) kJ mol-1. Uchida Y, Toyoda M, Kuze N, Sakaizumi T (2009) Microwave spectra, molecular structure and theoretical calculation of two isotopic species of acetyl isocyanate CD3C(O)NCO and 13CH3C(O)NCO. J Mol Spectrosc 256(1):163-168

413 CAS RN: 58246-17-6 MGD RN: 510938 GED augmented by DFT computations

Bonds N=O(4) N=O(6) C(2)–C(3) N–O(5) C(1)–O(5) C(2)–C(1) C–H Angles

2-Propyn-1-ol nitrate C3H3NO3 C1 (gauche) Cs (anti)

re [Å] a gauche anti 1.191(6) 1.191(6) 1.211(10) 1.215(10) 1.201(6) 1.201(6) 1.413(6) 1.398(7) 1.445(5) 1.447(9) 1.458(11) 1.448(7) 1.095(5) 1.095(5)

θe [deg] a

ra [Å] a gauche anti 1.194(5) 1.194(5) 1.214(9) 1.218(9) 1.204(5) 1.204(5) 1.427(6) 1.408(6) 1.459(5) 1.456(9) 1.466(10) 1.452(6) 1.097(6) 1.095(5)

θa [deg] a

334

5 Molecules with Three Carbon Atoms

C(2)–C(1)–O(5) C(1)–O(5)–N O(5)–N=O(4) O(5)–N=O(6) O(4)=N=O(6)

Dihedral angles N–O(5)–C(1)–C(2) O(4)=N–O(5)–C(1)

gauche 110.7(5) 112.4(4) 112.4(9) 116.2(3) 131.5(8)

gauche 86(1) 168(2)

anti 108.1(5) 112.4(4) 112.8(9) 116.1(3) 131.2(8)

τe [deg] a

anti 180 b 0b

gauche 110.3(4) 113.7(3) 111.3(8) 116.8(3) 131.9(7)

gauche 83.8(9) 168(1)

anti 107.7(5) 113.7(3) 111.7(8) 116.7(3) 131.6(7)

τa [deg]

a

anti 180 b 0b

Tables 2 and 3 reproduced with permission from de Gruyter, Berlin.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

anti

gauche

The GED experiment was carried out at room temperature. The title compound was found to exist as a mixture of anti (69(2)%) and gauche (31(2)%) conformers with the antiperiplanar and synclinal N–O(5)–C(1)–C(2) dihedral angles, respectively. In each conformer, the NO3 group was assumed to be planar and the HCCC fragment was assumed to be linear. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP/6-311++G** harmonic and anharmonic force fields taking into account non-linear kinematic effects. Klapötke TM, Krumm B, Moll R, Penger A, Sproll SM, Berger RJF, Hayes SA, Mitzel NW (2013) Structures of energetic acetylene derivatives HC≡CCH2ONO2, (NO2)3CCH2C≡CCH2C(NO2)3 and trinitroethane, (NO2)3CCH3. Z Naturforsch, B 68 (5-6):719-731

414 CAS RN: MGD RN: 354279 MW augmented by ab initio calculations

2-Propyn-1-ol – argon (1/1) Propargyl alcohol – argon (1/1) C3H4ArO C1 C C

Distances Rcm b Ar…H(4) rc

r0 [Å] a 2.079 2.834 3.901

Angle Ar…H(4)–O

θ0 [deg] a

Dihedral angle C(3)–O–H(4)…Ar

τ0 [deg] a

144.8

35.6

H

OH

Ar

5 Molecules with Three Carbon Atoms

335

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of propargyl alcohol. c Distance between Ar and the center of the C(1)≡C(2) bond. b

The rotational spectrum of the title complex was recorded by a pulsed-jet FTMW spectrometer in the frequency range from 5 to 19 GHz. The propargyl alcohol subunit was found to have gauche conformation, characterized by the synclinal C–C–O–H torsional angle; the Ar atom was found to be located between the hydroxyl and the acetylenic groups. The spectrum revealed a small splitting due to the large-amplitude vibrational-tunnelling motion dominated by the torsion about the O–C bond. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main and two D2); the remaining structural parameters were fixed at the values from MP2/6-311++G(3df,2p) calculations. Mani D, Arunan E (2013) Microwave spectroscopic and atoms in molecules. Theoretical investigations on the Ar⋅⋅⋅propargyl alcohol complex: Ar⋅⋅⋅H-O, Ar⋅⋅⋅π, and Ar⋅⋅⋅C interactions. ChemPhysChem 14(4):754-763

415 CAS RN: MGD RN: 214210 MW supported by ab initio calculations

Ethyne – chlorofluoromethane (1/1) Acetylene – chlorofluoromethane (1/1) C3H4ClF Cs H H

Distances Cl…H(1) r1 b r2 c

r0 [Å] a 3.207(22) 3.605(4) 3.236(6)

Angles

θ0 [deg] a

d

ϕ1 ϕ2 e

C(1)–H(1)…Cl

C

C

H

H Cl

F

73.9(9) 91.87(27) 109.0(10)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are one σ values. Distance between C(2) and the midpoint of the C≡C bond. c Distance between the methylene H atom and the midpoint of the C≡C bond. d Angle between r1 and the C∞ axis in the ethyne subunit. e Angle between r1 and the C(2)–Cl bond. b

The rotational spectrum of the binary complex of acetylene with chlorofluoromethane was recorded in a supersonic jet by chirped-pulsed and Balle-Flygare type FTMW spectrometers in the frequency region between 7 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 37 Cl, 13C2 and 37Cl/13C2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation.

336

5 Molecules with Three Carbon Atoms

Elmuti LF, Peebles RA, Peebles SA, Steber AL, Neill JL, Pate BH (2011) Observation of a double C-H⋅⋅⋅π interaction in the CH2ClF⋅⋅⋅HCCH weakly bound complex. Phys Chem Chem Phys 13(31):14043-14049

416 CAS RN: MGD RN: 435412 MW augmented by ab initio calculations

2-Chloro-2-(difluoromethoxy)-1,1,1-trifluoroethane – water (1/1) Isoflurane – water (1/1) C3H4ClF5O2 C1 F F

Distances O(13)…H(2) C(1)–C(2) C(2)–O(3) O(3)–C(4) C(1)–F(5) C(1)–F(6) C(1)–F(7) C(4)–H(1) C(4)–F(9) C(4)–F(10) C(2)–Cl(11) C(2)–H(2) O(13)–H(3) O(13)–H(4)

r0 [Å]a 2.152(3) 1.526 b 1.410 b 1.365 b 1.338 b 1.334 b 1.331 b 1.087 b 1.363 b 1.353 b 1.767 b 1.090 b 0.961 b 0.961 b

Bond angles C(1)–C(2)–O(3) C(2)–O(3)–C(4) C(2)–C(1)–F(5) C(2)–C(1)–F(6) C(2)–C(1)–F(7) O(3)–C(4)–H(1) O(3)–C(4)–F(9) O(3)–C(4)–F(10) C(1)–C(2)–Cl(11) C(1)–C(2)–H(2) O(13)…H(2)–C(2) H(3)–O(13)…H(2) H(4)–O(13)…H(2)

θ0 [deg]a

Dihedral angles C(1)–C(2)–O(3)–C(4) O(3)–C(2)–C(1)–F(5) O(3)–C(2)–C(1)–F(6) O(3)–C(2)–C(1)–F(7) C(2)–O(3)–C(4)–H(1) C(2)–O(3)–C(4)–F(9) C(2)–O(3)–C(4)–F(10) F(6)–C(1)–C(2)–Cl(11) F(6)–C(1)–C(2)–H(2) C(1)–C(2)–H(2)…O(13) C(2)–H(2)…O(13)–H(3) C(2)–H(2)…O(13)–H(4)

τ0 [deg]

106.3 b 115.2 b 110.5 b 112.3 b 109.4 b 108.2 b 111.1 b 111.7 b 109.8 b 108.3 b 180.9(4) 132.0 b 109.6 b

136.4 b -179.7 b 59.0 b -61.0 b 176.4 b -63.4 b 54.7 b 178.6 b 60.3 b -23.5 b 55.6 b -76.6 b

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

F

O

F F

Cl

O H

H

5 Molecules with Three Carbon Atoms a b

337

Parenthesized uncertainty in units of the last significant digit. Fixed at the value from MP2/6-311++G(d,p) calculations.

The rotational spectrum of the complex was recorded in a supersonic jet by an FTMW spectrometer in the frequency range between 7 and 14 GHz. Only one conformer with an almost linear C–H…O weak hydrogen bond was detected. The other conformer, with an O–H…O hydrogen bond, predicted by ab initio to be the most stable one, was not observed. The partial structure was determined from the ground-state rotational constants of five isotopic species (main, 37 Cl, 18O, D and D2); the values of remaining structural parameters were adopted from calculations at the level of theory as indicated above. Gou Q, Feng G, Evangelisti L, Vallejo-López M, Spada L, Lesarri A, Cocinero EJ, Caminati W(2014) How water interacts with halogenated anesthetics: The rotational spectrum of isoflurane–water. Chem Eur J 20:19801984

417 CAS RN: 1352546-49-6 MGD RN: 330442 MW augmented by ab initio calculations

Ethene – trifluoroiodomethane (1/1) Ethylene – trifluoroiodomethane (1/1) C3H4F3I Cs F

Distances C–H C=C Rb

r0 [Å] a 1.0852 1.3407 3.7729(15)

Angle C=C–H

θ0 [deg]

F

F

I

H

H

H

H

121.15

Copyright 2012 with permission from Elsevier.

a b

Parenthesized uncertainty in units of the last significant digit. Distance between I and the center-of-mass of the ethylene subunit.

The rotational spectrum of the binary complex was recorded by a chirped-pulse FTMW spectrometer in the frequency region between 5 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of only one isotopic species; the structural changes of the ethylene and the trifluoroiodomethane upon complexation were assumed according to CCSD(T/cc-pVTZ(F12*) calculations. The C-I…X arrangement (X is the midpoint of the C=C bond) is linear due to the interaction of the iodine atom with the π-electron of the C=C double bond. Stephens SL, Mizukami W, Tew DP, Walker NR, Legon AC (2012) The halogen bond between ethene and a simple perfluoroiodoalkane: C2H4⋅⋅⋅ICF3 identified by broadband rotational spectroscopy. J Mol Spectrosc 280:47-53

418 CAS RN: MGD RN: 538020

Oxirane – tetrafluoromethane (1/1) Ethylene oxide – tetrafluoromethane (1/1) C3H4F4O

338

5 Molecules with Three Carbon Atoms

MW supported by ab initio calculations

Distance C(1)…O

r0 [Å] 3.341

Angles

θ0 [deg] a

α

b

Cs F O

F

F

F

104.5(3)

Copyright 2017 with permission from Elsevier. a b

Parenthesized uncertainty in units of the last significant digit. Angle between the C2 axis of the oxirane subunit and C(1)…O.

The rotational spectrum of the binary complex of oxirane with tetrafluoromethane was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 6.5 and 18.6 GHz. The partial r0 structure was determined under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. No experimental evidence of the internal rotation of CF4 with respect to oxirane subunit was observed, although it was expected to be almost free according to prediction of MP2/6-311++G(3df,3pd) calculations. Gou Q, Feng G, Evangelisti L, Caminati W (2017) Rotational spectrum of the tetrafluoromethane-ethylene oxide. J Mol Spectrosc 335(5):84-87

419 CAS RN: 26035-26-7 MGD RN: 442673 MW supported by ab initio calculations

1,1,1,3,3,3-Hexafluoro-2-propanol – water (1/1) 1,1,1,3,3,3-Hexafluoroisopropanol – water (1/1) C3H4F6O2 OH C1 F

F

F

Distances d1 b d2 c d3 d

F

F

O H

H

F

r0 [Å] a 3.19588(83) 3.88827(70) 1.7962(34)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the center-of-mass of the alcohol subunit and H(1). c Distance between the center-of-mass of the alcohol subunit and H(2). d Distance between the center-of-mass of the alcohol subunit and H(3). b

The rotational spectra of the binary complex of hexafluoroisopropanol with water were recorded in a pulsed supersonic jet by an FTMW spectrometer in the frequency region between 3 and 16 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main and three D). Shahi A, Arunan E (2015) Microwave spectroscopic and theoretical investigations of the strongly hydrogen bonded hexafluoroisopropanol⋅⋅⋅water complex. Phys Chem Chem Phys 17(38):24774-24782

5 Molecules with Three Carbon Atoms

420 CAS RN: 130974-24-2 MGD RN: 214897 MW augmented by QC calculations

Bonds N(1)–H C(2)=N(1) C(2)–C(3) C(1)–C(2) C(3)≡N(2) C(1)–H(2) Bond angles H–N(1)=C(2) N(1)=C(2)–C(3) N(1)=C(2)–C(1) C(2)–C(3)≡N(2) C(2)–C(1)–H(2) C(2)–C(1)–H(1)

339

(2E)-2-Iminopropanenitrile trans-Iminopyruvonitrile C3H4N2 Cs H

N

r0 [Å] a 1.023(5) 1.278(3) 1.455(5) 1.507(5) 1.155(5) 1.092(2)

C

H 3C

N

θ0 [deg] a 109.5(5) 117.0(5) 128.1(5) 177.0 110.5 109.4

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure of the title molecule was determined by adjusting the MP2_full/6-311+G(d) structure to the previously published ground-state rotational constants. Durig JR, Zhou SX, Zhou CX, Durig NE (2010) Structural parameters, vibrational spectra and centrifugal distortion constants of F(CN)C=NX (X = H, F, Cl, Br) and CH3(Y)C=NH (Y = H, CN). J Mol Struct 967(1-3):114

421 CAS RN: 130974-24-2 MGD RN: 119199 MW augmented by QC calculations

(2Z)-2-Iminopropanenitrile cis-Iminopyruvonitrile C3H4N2 Cs H

N

Bonds N(1)–H C(2)=N(1) C(2)–C(3) C(1)–C(2) C(3)≡N(2) C(1)–H(2)

r0 [Å] a 1.023(3) 1.280(3) 1.457(3) 1.502(3) 1.158(3) 1.090(2)

Bond angles H–N(1)=C(2) N(1)=C(2)–C(3) N(1)=C(2)–C(1)

θ0 [deg] a 110.7(5) 122.2(5) 121.7(5)

H 3C

C N

340

C(2)–C(3)–N(2) C(2)–C(1)–H(2) C(2)–C(1)–H(1)

5 Molecules with Three Carbon Atoms

179.2 109.0 109.9

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structure of the title molecule was determined by adjusting the MP2_full/6-311+G(d) structure to the previously published ground-state rotational constants. Durig JR, Zhou SX, Zhou CX, Durig NE (2010) Structural parameters, vibrational spectra and centrifugal distortion constants of F(CN)C=NX (X = H, F, Cl, Br) and CH3(Y)C=NH (Y = H, CN). J Mol Struct 967(1-3):114

422 CAS RN: 288-13-1 MGD RN: 961946 MW augmented by DFT calculations

1H-Pyrazole C3H4N2 Cs N

Bonds N(1)–H N(1)–N(2) N(2)=C(3) N(1)–C(5) C(3)–C(4) C(4)=C(5) C(3)–H C(4)–H C(5)–H

r m [Å] a 0.9956(4) 1.348(1) 1.329(1) 1.354(1) 1.411(1) 1.376(1) 1.0763(4) 1.0738(4) 1.0751(4)

r e [Å] a 1.0014(4) 1.3431(6) 1.3286(7) 1.3523(6) 1.4093(6) 1.3771(8) 1.0755(4) 1.0736(4) 1.0740(5)

Bond angles H–N(1)–N(2) H–N(1)–C(5) N(2)–N(1)–C(5) N(1)–N(2)–C(3) N(1)–C(5)=C(4) N(1)–C(5)–H C(4)=C(5)–H N(2)=C(3)–C(4) N(2)=C(3)–H C(4)–C(3)–H C(5)=C(4)–C(3) C(5)=C(4)–H C(3)–C(4)–H

θ (1) [deg] a m

θ see [deg] a

(1)

118.61(12) 128.32(13) 113.07(5) 104.12(4) 106.36(4) 121.47(10) 132.16(9) 111.97(5) 119.59(14) 128.44(15) 104.48(3) 127.67(11) 127.85(12)

se

118.97(11) 127.79(12) 113.24(5) 104.18(3) 106.23(4) 121.84(11) 131.93(10) 111.90(5) 119.49(14) 128.62(15) 104.46(4) 127.23(13) 128.32(13)

Reprinted with permission. Copyright 2014 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit.

N H

5 Molecules with Three Carbon Atoms

341

(1)

The mass-dependent structure r m was determined from the previously published ground-state rotational se

constants. The semiexperimental equilibrium structure r e was obtained taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the B3LYP/6-311+G(3df,2pd) harmonic and anharmonic (cubic) force fields. Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and sevenmembered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746

423 CAS RN: 288-32-4 MGD RN: 786562 MW augmented by DFT calculations

1H-Imidazole C3H4N2 Cs N

Bonds N(1)–C(2) N(1)–C(5) N(1)–H C(2)=N(3) C(2)–H N(3)–C(4) C(4)=C(5) C(4)–H C(5)–H

r m [Å] a 1.3612(10) 1.3735(10) 0.9952(4) 1.3093(8) 1.0769(4) 1.3788(9) 1.3605(9) 1.0756(4) 1.0763(4)

r e [Å] a 1.3594(3) 1.3758(3) 1.0013(1) 1.3114(2) 1.0761(1) 1.3774(3) 1.3663(3) 1.0749(2) 1.0734(3)

Bond angles C(2)–N(1)–C(5) C(2)–N(1)–H C(5)–N(1)–H N(1)–C(2)=N(3) N(1)–C(2)–H N(3)=C(2)–H C(2)=N(3)–C(4) N(3)–C(4)=C(5) N(3)–C(4)–H C(5)=C(4)–H N(1)–C(5)=C(4) N(1)–C(5)–H C(4)–C(5)–H

θ (m2) [deg] a

θ see [deg] a

( 2)

106.90(4) 126.27(11) 126.83(11) 111.97(4) 122.44(9) 125.59(9) 104.99(4) 110.64(4) 121.46(8) 127.90(8) 105.50(4) 121.95(9) 132.55(9)

se

N H

107.18(1) 126.44(4) 126.38(3) 111.90(2) 122.39(3) 125.71(3) 105.08(2) 110.69(2) 121.48(3) 127.83(4) 105.16(3) 122.29(3) 132.56(4)

Reprinted with permission. Copyright 2014 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit. ( 2)

The mass-dependent structure r m was determined from the previously published ground-state rotational se

constants of eleven isotopic species. The semiexperimental equilibrium structure r e was obtained taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the B3LYP/6-311+G(3df,2pd) harmonic and anharmonic (cubic) force fields. Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and sevenmembered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746

342

5 Molecules with Three Carbon Atoms

424 CAS RN: 107-02-8 MGD RN: 188501 MW augmented by QC calculations

2-Propenal Acrolein C3H4O Cs (s-trans) Cs (s-cis) O

Bonds C(1)=O(4) C(1)–C(2) C(2)=C(3) C(1)–H(5) C(2)–H(6) C(3)–H(7) C(3)–H(8) Bond angles C(2)–C(1)=O(4) C(3)=C(2)–C(1) C(2)–C(1)–H(5) C(3)=C(2)–H(6) C(2)=C(3)–H(7) C(2)=C(3)–H(8)

s-trans se r e [Å] a 1.2105(1) 1.4700(1) 1.3356(2) 1.1049(2) 1.0815(1) 1.0827(2) 1.0792(2)

s-cis se r e [Å] a 1.2101(3) 1.4818(4) 1.3359(4) 1.1020(3) 1.0814(3) 1.0810(5) 1.0791(3)

θ see [deg] a

θ see [deg] a

123.99(1) 120.22(1) 115.02(2) 122.76(2) 120.43(1) 122.09(2)

H2C

H

s-trans

123.88(3) 121.28(3) 115.82(4) 121.59(4) 119.84(3) 121.59(5)

Reprinted with permission. Copyright 2014 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit.

s-cis

se

The semiexperimental equilibrium structures r e were determined for both conformers from the previously published ground-state rotational constants of eight isotopic species. The rovibrational corrections, ΔBe = Be ‒ B0, were calculated with the B2PLYP/aug-cc-pVTZ harmonic and anharmonic (cubic) force fields. The obtained structures were found to be in remarkable agreement with the CCSD(T)/aug-cc-pVQZ geometries corrected for core-valence correlation effect and extrapolated to the complete basis set limit. At this level of theory, the s-trans conformer is more stable than the s-cis one by 729.3 cm-1. Puzzarini C, Penocchio E, Biczysko M, Barone V (2014) Molecular structure and spectroscopic signatures of acrolein: theory meets experiment. J Phys Chem A 118(33):6648-6656

425 CAS RN: 1356407-09-4 MGD RN: 209250 MW supported by ab initio calculations

Thiirane – carbon monoxide (1/1) Ethylene sulfide – carbon monoxide (1/1) C3H4OS Cs S

Distances C(2)–S C(2)–C(2ꞌ) S…C(1) C(1)≡O(1)

rs [Å] a 1.813 1.480 3.470 1.117

C

O

5 Molecules with Three Carbon Atoms

Rcm b

3.796

Angles

θs [deg] a

c

φ ϕd

343

74.6 67.0

Reprinted with permission. Copyright 2011 American Chemical Society

a

Uncertainties were not given in the original paper. Distance between centers of mass of both monomer subunits. c Angle between ring plane and C(1). d Complementary angle between C(1)…S and C(1)–O(1). b

The rotational spectrum of the binary complex of thiirane with carbon monoxide was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 31 GHz. The partial rs structure was determined from the ground-state rotational constants of five isotopic species (main, 34 S, two 13C and 18O). Kawashima Y, Sato A, Orita Y, Hirota E (2012) Intermolecular interaction between CO or CO2 and ethylene oxide or ethylene sulfide in a complex, investigated by Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 116(4):1224-1236

426 CAS RN: 79-10-7 MGD RN: 643366 MW augmented by QC calculations

2-Propenoic acid Acrylic acid C 3H 4O 2 Cs O

H 2C

Bonds

s-cis r0 [Å] a

C(1)=C(2) C(2)–C(3) O(5)–H

1.340(9) 1.486(2) 0.957(4)

1.340 1.454

r e [Å] b 1.334 1.477

Bond angle

θ0 [deg] a

θs [deg] b

C(1)=C(2)–C(3)

119.4(5)

121.0

θ se [deg] b

Bonds

s-trans r0 [Å] a

rs [Å] b

C(1)=C(2) C(2)–C(3) O(5)–H

1.325(8) 1.487(4) 0.958(7)

1.339 1.484

r e [Å] b 1.334 1.472

Bond angle

θ0 [deg] a

θs [deg] b

C(1)=C(2)–C(3)

123.5(2)

122.4

θ se [deg] b

Copyright 2014 with permission from Elsevier.

rs [Å] b

s

120.2

s

123.6

OH

344 a b

5 Molecules with Three Carbon Atoms

Parenthesized uncertainties in units of the last significant digit. Uncertainties were not given in the original paper.

s-cis

s-trans

The rotational spectra of the title compound were recorded by a supersonic-jet FTMW spectrometer in the frequency region between 6 and 18.5 GHz and by a Stark-modulated free-jet millimeter-wave spectrometer in the region between 52 and 74.4 GHz. The measured lines were assigned to two conformers, s-cis and s-trans, with the synperiplanar and antiperiplanar O(4)=C–C=C torsional angles, respectively. The partial r0 structure of both conformers were obtained from the ground-state rotational constants of five s isotopic species (main, three 13C and D) each. The semiempirical structures r e were derived by applying the Kraitchman procedure to the ground-state rotational constants corrected for rovibrational contributions calculated with the B3LYP/aug-cc-pVTZ harmonic and anharmonic (cubic) force fields. Calabrese C, Vigorito A, Feng G, Favero LB, Maris A, Melandri S, Geppert WD, Caminati W (2014) Laboratory rotational spectrum of acrylic acid and its isotopologues in the 6-18.5 GHz and 52-74.4 GHz frequency ranges. J Mol Spectrosc 295:37-43

427 CAS RN: 1356407-07-2 MGD RN: 333200 MW supported by ab initio calculations

Oxirane – carbon monoxide (1/1) Ethylene oxide – carbon monoxide (1/1) C 3H 4O 2 Cs O

Distances C(2)–O(2) C(2)–C(2ꞌ) O(2)…C(1) C(1)≡O(1) Rcm b

rs [Å] a 1.429 1.478 3.015 1.122 3.607

Angles

θs[deg] a

c

φ ϕd

C

O

97.5 75.6

Reprinted with permission. Copyright 2011 American Chemical Society

a

Uncertainties were not given in the original paper. Distance between the centers of mass of the monomer subunits. c Angle between ring plane and C(1). d Complementary angle between C(1)…O(2) and C(1)≡O(1). b

The rotational spectrum of the binary complex of oxirane with carbon monoxide was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 31 GHz. The partial rs structure was determined from the ground-state rotational constants of five isotopic species (main, two 13C and two 18O).

5 Molecules with Three Carbon Atoms

345

Kawashima Y, Sato A, Orita Y, Hirota E (2012) Intermolecular interaction between CO or CO2 and ethylene oxide or ethylene sulfide in a complex, investigated by Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 116(4):1224-1236

428 CAS RN: 1356407-10-7 MGD RN: 213620 MW supported by ab initio calculations

Thiirane – carbon dioxide (1/1) Ethylene sulfide – carbon dioxide (1/1) C3H4O2S Cs O

S

Distances C(2)–S C(2)–C(2ꞌ) S…C(1) C(1)=O Rcm b

rs [Å] a 1.811 1.484 3.337 1.162 3.471

Angles

θs[deg] a

φc ϕd

C

O

91.6 84.3

Reprinted with permission. Copyright 2011 American Chemical Society

a

Uncertainties were not given in the original paper. Distance between the centers of mass of the monomer subunits. c Angle between ring plane and C(1). d Complementary angle between C(1)…S and C(1)=O(1). b

The rotational spectrum of the binary complex of thiirane with carbon dioxide was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 31 GHz. The partial rs structure was determined from the ground-state rotational constants of seven isotopic species (main, 34S, two 13C, two 18O and 18O2). Kawashima Y, Sato A, Orita Y, Hirota E (2012) Intermolecular interaction between CO or CO2 and ethylene oxide or ethylene sulfide in a complex, investigated by Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 116(4):1224-1236

429 CAS RN: 2258-42-6 MGD RN: 647513 MW

Formic acetic anhydride C 3H 4O 3 Cs O

Bonds C(1)–C(2) C(2)=O(3) C(2)–O(4) O(4)–C(5) C(5)=O(6) C(5)–H

r0 [Å] a 1.510(10) 1.195(10) 1.364(10) 1.388(10) 1.185(10) 1.100(10)

H

O

O

CH3

346

5 Molecules with Three Carbon Atoms

C(1)–H

1.100(10)

Bond angles C(1)–C(2)=O(3) C(1)–C(2)–O(4) C(2)–O(4)–C(5) O(4)–C(5)=O(6) O(4)–C(5)–H C(2)–C(1)–H

θ0 [deg] a 125.0(5) 109.0(5) 118.0(5) 120.6(5) 112.2(5) 109.5(5)

Reprinted by permission of Taylor & Francis Ltd. Final version received 12 February 2013

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of formic acetic anhydride was recorded between 6.5 and 18 GHz using phase-stabilized backward-wave oscillators. The r0 structure was obtained by adjusting the substitution structure of formic anhydride and the usual parameters of the methyl group to the ground-state rotational constants of the main isotopic species. The barrier to internal rotation of the methyl group was determined to be 254.711(38) cm-1. Bauder A (2013) Microwave spectrum of formic acetic anhydride. Mol Phys 111(14-15):1999-2002

430 CAS RN: 1356407-08-3 MGD RN: 213434 MW supported by ab initio calculations

Oxirane – carbon dioxide (1/1) Ethylene oxide – carbon dioxide (1/1) C 3H 4O 3 Cs O

Distances C(2)–O(2) C(2)–C(2ꞌ) O(2)…C(1) C(1)=O(1) Rcm b

rs [Å] a 1.420 1.469 2.800 1.166 3.259

Angles

θs[deg] a

φc ϕd

O

C

O

116.1 86.8

Reprinted with permission. Copyright 2011 American Chemical Society

a

Uncertainties were not given in the original paper. Distance between the centers of mass of the monomer subunits. c Angle between the ring plane and C(1). d Complementary angle between C(1)…O(2) and C(1)=O(1). b

The rotational spectrum of the binary complex of oxirane with carbon dioxide was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 31 GHz. The rs structure was determined from the ground-state rotational constants of seven isotopic species (main, two 13 C, three 18O and 18O2).

5 Molecules with Three Carbon Atoms

347

Kawashima Y, Sato A, Orita Y, Hirota E (2012) Intermolecular interaction between CO or CO2 and ethylene oxide or ethylene sulfide in a complex, investigated by Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 116(4):1224-1236

431 CAS RN: MGD RN: 320737 MW supported by ab initio calculations

Fluoroethene – chlorofluoromethane (1/1) Fluoroethylene – chlorofluoromethane (1/1) C3H5ClF2 Cs H

Distances H(6)…Cl(3) H(4)…F(8)

r0 [Å] a 3.012(3) 2.764(5)

Angles C(2)-Cl(3)…H(6) Cl(3)…H(6)-C(7) F(8)…H(4)-C(2) C(7)-F(8)..H(4)

θ0 [deg] a

F

H

Cl

H

H

H

F

95.88(3) 125.22(12) 95.37(4) 125.94(12)

Copyright 2012 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the binary complex of fluoroethylene with chlorofluoromethane was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and with 37Cl) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The complex is formed by one H…Cl and two equivalent H…F hydrogen bonds. Christenholz CL, Obenchain DA, Peebles SA, Peebles RA (2012) Reduced bandwidth chirped-pulse microwave spectroscopy for analysis of weakly bound dimers: Rotational spectrum and structural analysis of CH2ClF⋅⋅⋅FHC=CH2. J Mol Spectrosc 280:61-67

432 CAS RN: 79-03-8 MGD RN: 704677 MW supported by DFT calculations

Propanoyl chloride Propionyl chloride C3H5ClO Cs O

H 3C a

Bonds C(1)–Cl C(1)–C(2) C(2)–C(3)

rs [Å] 1.750(3) 1.525(5) 1.527(3)

Bond angles Cl–C(1)–C(2)

θs [deg] a 113.2(3)

Cl

348

C(1)–C(2)–C(3)

5 Molecules with Three Carbon Atoms

114.0(3)

Dihedral angle τs [deg] Cl–C(1)–C(2)–C(3) 180 Reprinted with permission. Copyright 2010 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of propanoyl chloride were recorded by a chirped-pulse FTMW spectrometer in the frequency region between 8 and 184 GHz. The partial rs structure was determined from the ground-state rotational constants of five isotopic species (main, 37 Cl and three 13C). The barrier to internal rotation of the methyl group (2.44(10) kcal mol‒1) was obtained from the splittings in the rotational transitions. Grubbs GS, Powoski RA, Jojola D, Cooke SA (2010) Some geometric and electronic structural effects of perfluorinating propionyl chloride. J Phys Chem A 114(30):8009-8015

433 CAS RN: 4643-05-4 MGD RN: 364838 GED augmented by QC computations

Bonds C(1)–C(2) C(2)=C(3) C(3)–H C(3)–Cl C(1)–O O–H C(1)–Hʹ

(2Z)-3-Chloro-2-propenol C3H5ClO C1 (-ac,sc) Cs (ap,ap) Cl

ra[Å] a 1.5044(20) 1.3435(16) 1.0828(13) b 1.7366(19) 1.4299(14) 1.000 c 1.0938(13) b d

Bond angles C(1)–C(2)=C(3) C(2)=C(3)–H C(2)=C(3)–Cl C(2)–C(1)–O C(1)–O–H C(2)–C(1)–Hʹ O–C(1)–Hʹ

θα [deg]

Dihedral angles C(3)=C(2)–C(1)–O C(2)–C(1)–O–H

τα [deg] d

HO

-ac,sc

125.60(12) 124.1(10) 123.61(10) 111.0(2) 104.1(15) 103.2(10) 111.2(11)

-125.5(17) e 61.7 f

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated errors including 1σ values and a systematic error of 0.001r.

5 Molecules with Three Carbon Atoms

349

b

Difference between the C–H bond lengths was fixed. Fixed. d Parenthesized uncertainties in units of the last significant digit are 1σ values. e For ap,ap conformer, this angle was assumed to be 180°. f Adopted from MP2/cc-pVTZ computation. c

The GED experiment was carried out at Tnozzle = 340 K. In the GED analysis, the title compound was considered as a mixture of two conformers, -ac,sc and ap,ap, characterized by the anticlinal (ac) and antiperiplanar (ap) C(3)=C(2)–C(1)–O dihedral angles, respectively, as well as by the synclinal (sc) and antiperiplanar (ap) C(2)–C(1)–O–H dihedral angles, respectively. Each of the conformers was considered as doing framework vibrations in Gaussian distributed C(3)=C(2)–C(1)–O large amplitude torsions. The root-mean-square angular amplitudes of these motions were refined to be 28.6(12)° and 21.4(46)° for the -ac,sc and ap,ap conformers, respectively. The ratio of the conformers was determined to be -ac,sc : ap,ap = 83(3) : 17 (in %). The refined amount of the -ac,sc conformer included also contribution by the -ac,-sc conformer predicted by B3LYP and MP2 calculations (with cc-pVTZ basis set). These two conformers are differing in the direction of the O–H bonds only and could not be separated by GED. Vibrational corrections to the experimental internuclear distances, ∆rα = ra − rα, were calculated using harmonic force constants from MP2/cc-pVTZ computation. The lowest energy conformer is stabilized due to internal hydrogen bonding between the hydroxyl H atom and the π-system. Strand TG, Gundersen S, Priebe H, Samdal S, Seip R (2009) Molecular structures, conformations, force fields and large amplitude motion of cis-3-chloro-2-propen-1-ol as studied by quantum chemical calculations and gas electron diffraction augmented with quantum chemical calculations on 2-propen-1-ol. J Mol Struct 921 (1-3):7279

434 CAS RN: 598-78-7 MGD RN: 208670 MW augmented by ab initio calculations

2-Chloropropanoic acid 2-Chloropropionic acid C3H5ClO2 C1 O H 3C

Bonds H(1)–O(2) O(2)–C(3) C(3)–C(4) C(3)=O(5) C(4)–Cl(6) C(4)–H(7) C(4)–C(11) C(11)–H(9) C(11)–H(10) C(11)–H(8) Bond angles C(3)–C(4)–Cl(6) C(3)–C(4)–C(11) H(1)–O(2)–C(3) O(2)–C(3)–C(4) C(3)–C(4)–H(7) C(4)–C(11)–H(9) C(4)–C(11)–H(10) C(4)–C(11)–H(8)

r0 [Å] 0.972 b 1.346 b 1.513 b 1.206 b 1.795 b 1.090 b 1.508 b 1.092 b 1.089 b 1.090 b

θ0 [deg] a 107.1(5) 113.7(8) 106.6 b 111.1 b 109.2 b 109.7 b 110.3 b 110.1 b

OH Cl

350

Dihedral angles O(2)–C(3)–C(4)–Cl(6) O(2)–C(3)–C(4)–C(11) H(1)–O(2)–C(3)–C(4) H(1)–O(2)–C(3)=O(5) O(2)–C(3)–C(4)–H(7) C(3)–C(4)–C(11)–H(9) C(3)–C(4)–C(11)–H(10) C(3)–C(4)–C(11)–H(8)

5 Molecules with Three Carbon Atoms

τ0 [deg] a

75.7(8) -161.0(11) -177.5 b 2.4 b -33.9 b 62.4 b -56.9 b -177.7 b

Copyright 2008 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Fixed to MP2/6-311++G(2df,p) value.

The rotational spectra of the title compound were studied in a supersonic jet by FTMW spectroscopy in the spectral range between 6 and 18 GHz and by free-jet millimeter-wave direct-absorption spectroscopy in the spectral range between 50 and 75 GHz. Two conformer, syn and anti, with the synperiplanar and antiperiplanar C–C–C=O(5) torsional angles, respectively, were predicted by MP2 and B3LYP calculations (with MP2/6311++G(2df,p) basis set); the anti conformer is higher in energy than the syn one by 1.1…1.5 kJ mol-1. Only the syn conformer was detected. The partial r0 structure of this chiral molecule was determined from the ground-state rotational constants of two isotopic species (main and 37Cl). Lesarri A, Grabow JU, Caminati W (2009) Conformation of chiral molecules: The rotational spectrum of 2chloropropionic acid. Chem Phys Lett 468(1-3) 18-22

435 CAS RN: 96-34-4 MGD RN: 112531 GED augmented by ab initio computations

2-Chloroacetic acid methyl ester Methyl chloroacetate C3H5ClO2 C1 (I) Cs (II) O

C–H C(1)=O(5) C(1)–O(3) C(4)–O(3) C(1)–C(2) C–Cl

ra [Å] a,b c anticlinal (I) synperiplanar (II) 1.081(6) 1.079(6) 1.212(4) 1.208(4) 1.345(4) 1.352(4) 1.467(10) 1.468(10) 1.501(9) 1.505(9) 1.782(4) 1.763(4)

Bond angles

θh1 [deg] a,b

Bonds

H–C(2)–H C(1)–C(2)–Cl C(2)–C(1)=O(5) C(2)–C(1)–O(3) O(3)–C(4)–H C(1)–O(3)–C(4)

anticlinal (I) 111.5 c 110.0(6) 124.7(6) 108.3(10) 105.6 c 115.9(8)

Dihedral angles

τh1 [deg] a

anticlinal (I)

rh1[Å] a,b anticlinal (I) 1.084(6) 1.213(4) 1.346(4) 1.468(10) 1.502(9) 1.782(4)

Cl O

I

CH3

5 Molecules with Three Carbon Atoms

O(5)=C(1)–C(2)–Cl O(5)=C(1)–O(3)–C(4) C(1)–O(3)–C(4)–H(6)

351

111(2) 3(3) 180 c

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 2σ values. b Differences between related parameters of the conformers were assumed at the values from MP3/6-311+G(d,p) computations. c Adopted from computation as indicated above.

II

The GED experiment was carried out at Tnozzle = 298 K. The title molecule was found to exist as a mixture of two conformers, I and II, with the anticlinal and synperiplanar O=C−C−Cl torsional angles, respectively. The refined ratio of the conformers (in %) I : II = 64(8) : 36(8) corresponds to a free energy difference of ∆G° = 1.4(9) kJ mol−1. Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using quadratic force constants from HF/6-311+G(d,p) computation. As for several related molecules, the experimental value of the C=O bond length in methyl chloroacetate was found to be longer than that computed by MP2 and MP3 methods in conjunction with the 6-311+G(d,p) basis set. The determined O−C(methyl) bond was found to be surprisingly long compared with computed value as well as with experimental values for similar molecules. Aarset K, Boldermo KG, Hagen K (2010) Molecular structure and conformational composition of methyl chloroacetate: An electron-diffraction and ab initio molecular orbital investigation. J Mol Struct 978 (1-3):104107

436 CAS RN: MGD RN: 414601 MW augmented by ab initio calculations

Fluoroaectic acid – formic acid (1/1) C3H5FO4 Cs

O

O

F

a

Bonds C(1)…C(6) C(1)–C(2) C(2)–F(3) C(1)=O(4) C(1)–O(5) C(2)–H(1) O(5)–H(3) C(6)=O(7) C(6)–O(8) C(6)–H(5) O(8)–H(4)

r0 [Å] 3.786(2) 1.5158 b 1.3726 b 1.2192 b 1.3252 b 1.0930 b 0.9910 b 1.2221 b 1.3178 b 1.0948 b 0.9897 b

Bond angles C(1)–C(2)–F(3) C(2)–C(1)=O(4) C(2)–C(1)–O(5) C(1)–C(2)–H(1) C(1)–O(5)–H(3) O(7)=C(6)–O(8) O(7)=C(6)–H(5)

θ0 [deg] a 110.9 b 123.8 b 110.3 b 108.9 b 108.9 b 126.3 b 122.3 b

OH

H

OH

352

5 Molecules with Three Carbon Atoms

C(6)–O(8)–H(4) C(6)…C(1)=O(4) C(1)…C(6)=O(7)

108.8 b 59.9(2) 57.8 b

Dihedral angles O(4)=C(1)–C(2)–F(3) O(5)–C(1)–C(2)–F(3) H(1)–C(2)–C(1)–O(5)

τ0 [deg] 0 180 59.5 b

Copyright 2014 with permission from Elsevier.

a b

Parenthesized uncertainty in units of the last significant digit. Assumed at the value from MP2/6-311++G(d,p) calculation.

The rotational spectra of the complex of fluoroacetic acid with formic acid were recorded by a pulsed-jet cavitybased FTMW spectrometer in the frequency region between 6 and 18 GHz. The partial r0 structure was obtained from the ground-state rotational constants of four isotopic species (main and three D); the remaining structural parameters were assumed as the calculated values (see above). The deuterations of the hydroxyl groups increase the distance between the subunits of the complex (Ubbelohde effect). Evangelisti L, Feng G, Gou Q, Caminati W (2014) The rotational spectrum of formic acid⋅⋅⋅fluoroacetic acid. J Mol Spectrosc 299:1-5

437 CAS RN: MGD RN: 417258 MW supported by ab initio calculations

Fluoroethene - difluoromethane (1/1) Vinyl fluoride – difluoromethane (1/1) C3H5F3 Cs

Distances F(1)…H(3) C(7)…C(4) F(5)…H(6) Rcm c

r0 [Å] a 2.521(27) 3.745(33) b 2.828(41) b 4.130(32) b

rs [Å] a

Angles H(3)…F(1)–C(7) C(4)–H(3)…F(1) C(7)…C(4)=C(2) C(7)–H(6)…F(5) C(4)–F(5)…H(6)

θ0 [deg] a

θs [deg] a

116.4(8) 124.2(7) 170.1(6) b 90.63(26) b 118.77(60) b

H

F

H

H

H

F

H

F

3.724(4)

167.3(13)

Reprinted with permission. Copyright 2014 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c Distance between the centers of mass of the monomer subunits. b

The rotational spectra of the binary complex of vinyl fluoride with difluoromethane were recorded in a supersonic jet both by a chirped-pulse FTMW and a Balle-Flygare type FTMW spectrometer in the frequency region between 6.5 and 20 GHz.

5 Molecules with Three Carbon Atoms

353

The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main and three 13C) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The partial rs structure was obtained for the carbon skeleton. The determined structure was found to be consistent with that calculated at the MP2/6-311++G(2d,2p) level of theory. Christenholz CL, Obenchain DA, Peebles RA, Peebles SA (2014) Rotational spectroscopic studies of C-H⋅⋅⋅F interactions in the vinyl fluoride⋅⋅⋅difluoromethane complex. J Phys Chem A 118(9):1610-1616

438 CAS RN: 1281588-43-9 MGD RN: 214025 MW supported by ab initio calculations

1,1,1-Trifluoro-2-propanone – water (1/1) 1,1,1-Trifluoroacetone – water (1/1) C3H5F3O2 Cs O

O

F

Distances O(2)…O(1) H(2)…O(1) b O(2)…H(1) b

r0 [Å] 2.915(3) 2.044 2.411

Angles O(2)…O(1)=C H(2)–O(2)…O(1) O(2)–H(2)…O(1) b H(2)…O(1)=C b O(2)…H(1)–C b

θ0 [deg] a

H

H

CH3

a

F

F

109.37(5) 21(2) 149 119 143

Reprinted with permission. Copyright 2011 American Chemical Society

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the binary complex of 1,1,1-trifluoroacetone with water was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 18 O, two D and D2) under the assumption that the structural parameters of the trifluoroacetone subunit were not changed upon complexation. The barrier to internal rotation of the methyl group (3.29 kJ mol‒1) was determined from the analysis of tunneling splittings. Favero LB, Evangelisti L, Maris A, Vega-Toribio A, Lesarri A, Caminati W (2011) How trifluoroacetone interacts with water. J Phys Chem A 115(34):9493-9497

439 CAS RN: 1820672-85-2 MGD RN: 468732 MW supported by ab initio calculations

2-Propenenitrile – water (1/1) Acrylonitrile – water (1/1) C3H5NO H Cs H

O H

C

Distances

r0 [Å] a

N H

H

354

5 Molecules with Three Carbon Atoms

H(1)…O H(2)…N

2.508(4) 2.331(3)

Angles O–H(2)…N H(2)…N≡C

θ0 [deg] a

145.66(1) 89.52(7)

Reprinted with permission. Copyright 2015 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the binary complex of acrylonitrile with water was recorded in a supersonic jet by a Stark-modulated millimeter-wave spectrometer in the frequency region between 59 and 73 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 18 O and two D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Calabrese C, Vigorito A, Maris A, Mariotti S, Fathi P, Geppert WD, Melandri S (2015) Millimeter wave spectrum of the weakly bound complex CH2=CHCN⋅⋅⋅H2O: structure, dynamics, and implications for astronomical search. J Phys Chem A 119(48):11674-11682

440 CAS RN: 114596-02-0 MGD RN: 147280 GED augmented by ab initio computations

Bonds P–C P–H C(2)–C(3) C(1)≡C(2) C–H Bond angles H–P–H C–P–H P–C–C C–C≡C H–C–H Dihedral angles C≡C–C–P H(4)–P–C–H(2) H(4)–P–C–H(1)

1,2-Propynylphosphine Propargylphosphine C3H5P Cs (I) C1 (II)

rh1 [Å] a Cs C1 1.871(2) 1.875(2) b c 1.416(6) 1.416(6) c,d 1.454(3) 1.457(3) b 1.206(4) 1.207(3) b 1.087(6) 1.087(6) d

C C

PH2

H

I

θh1 [deg] a

Cs 94.2(10) e 96.6(10) e 113.6(2) 176.0(7) 106.0(10) e

Cs 0.0 f

C1 94.2(10) e 96.2(10) e 108.5(5) b 176.0(11) b II

τh1 [deg] a

C1 163.3(14) e -76.6(14) e 41.1(13) e

Reprinted with permission. Copyright 2009 American Chemical Society.

5 Molecules with Three Carbon Atoms

355

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Difference to corresponding parameter of the dominant conformer was restrained to the values from MP2/6311++G** computation. c Dependent parameter. d Average value. e Restrained to the value from computation as indicated above. f According to symmetry. b

The GED experiment was carried out at the nozzle temperatures of 253 and 263 K at the long and short nozzleto-plate distances, respectively. Two conformers, I and II, were considered in the GED model. In the conformer I, the C–C–P–H dihedral angles are ±synclinal (Cs overall symmetry), whereas in the conformer II, one C–C–P–H dihedral angle is approximately antiperiplanar and the other one is approximately synclinal (C1 point-group symmetry). The amount of the Cs conformer was determined to be 68(5) %. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/6-311++G** computation. Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612

441 CAS RN: 133672-87-4 MGD RN: 152866 GED augmented by ab initio computations

1,2-Propadienylphosphine Allenylphosphine C3H5P Cs H

PH2

C

Bonds P–C P–H C(1)=C(2) C(2)=C(3) C–H

rh1 [Å] a 1.836(2) 1.429(6) b 1.316(2) b 1.316(2) b 1.086(8) c

Bond angles H–P–H C–P–H P–C–C C–C–C P–C–H H–C–H

θh1 [deg] a

H

C

C H

92.4(10) d 97.7(9) d 120.0(4) 177.6(7) d 119.5(9) d 118.3(10) d

Reprinted with permission. Copyright 2009 American Chemical Society [a]

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Derived from the refined average value of r(P–H) and r(C=C) and the differences between these distances restrained to the values from computation at the level of theory as indicated below. c Average value. d Restrained to the value from computation at the level of theory as indicated below. b

Two conformers, I and II, were detected in the previous MW study [b]. The conformer I is characterized by two ±anticlinal C–C–P–H dihedral angles (Cs overall symmetry), whereas the conformer II is described by two

356

5 Molecules with Three Carbon Atoms

different C–C–P–H dihedral angles, one approximately synperiplanar and the other one approximately anticlinal (C1 point-group symmetry). However, the second conformer could not be detected by GED (Tnozzle= 230 K). The presence of impurities could not be excluded. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/6-311++G** computation. a. Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612 b. Møllendal H, Demaison J, Petiprez D, Wlodarczak G, Guillemin J-C (2005) Structural and conformational properties of 1,2-propadienylphosphine (allenylphosphine) studied by microwave spectroscopy and quantum chemical calculations. J Phys Chem A 109:115-121.

442 CAS RN: 115-07-1 MGD RN: 257399 MW augmented by QC calculations

1-Propene Propylene C 3H 6 Cs H 2C

Bonds C(1)=C(2) C(2)–C(3) C(1)–H(1) C(1)–H(2) C(2)–H(3) C(3)–H(4) C(3)–H(5)

r e [Å] a 1.33148(26) 1.49530(25) 1.08246(31) 1.08124(26) 1.08497(19) 1.088664(88) 1.09197(16)

Bond angles C(1)=C(2)–C(3) C(2)=C(1)–H(1) C(2)=C(1)–H(2) C(1)=C(2)–H(3) C(2)–C(3)–H(4) C(2)–C(3)–H(5)

θ see [deg] a

Dihedral angle C(1)=C(2)–C(3)–H(5)

CH3

se

124.4570(50) 121.154(18) 121.407(32) 118.798(85) 111.025(12) 110.890(21)

τ see [deg] a

120.627(27)

Reprinted with permission. Copyright 2017 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of propene-3-d1 was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 10 and 22 GHz. se The improved semiexperimental equilibrium structure r e was obtained from the determined rotational constants of 3-d1 species together with the previously published rotational constants of twenty isotopic species. Rovibrational corrections, ΔBe = Be ‒ B0, were calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields.

5 Molecules with Three Carbon Atoms

357

Demaison J, Craig NC, Gurusinghe R, Tubergen MJ, Rudolph HD, Coudert LH, Szalay PG, Császár AG (2017) Fourier transform microwave spectrum of propene-3-d1 (CH2=CHCH2D), quadrupole coupling constants of deuterium, and a semiexperimental equilibrium structure of propene. J Phys Chem A 121(16):3155-3166

443 CAS RN: MGD RN: 461780 MW augmented by ab initio calculations

Cyclopropane – silver chloride (1/1) C3H6AgCl C2v Ag

Distances Ag–Cl Ag…X b C(2)–C(2) C(1)–C(2) C(2)–H C(1)–H

r0 [Å] a 2.2793(36) 2.3078(46) 1.5966(29) 1.501(9) 1.0820 c 1.0797 c

Angles H–C(2)…X H–C(1)…X

θ0 [deg] a

Dihedral angle H–C(2)…X…C(1)

τ0 [deg]

Cl

rs [Å] a 2.275(79)

117.7(4) 121.7(6)

105.20 c

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. X is the midpoint of C(2)–C(2). c Constrained to the value from CCSD(T)/aug-cc-pVTZ-F12 computation. b

The rotational spectra of the binary complex of cyclopropane with silver chloride were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The complex was produced by a gas phase reaction of laser-ablated silver with tetrachloromethane and cyclopropane. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, 109 Ag, 37Cl, 109Ag/37Cl, two D2 and two 109Ag/D2); the remaining structural parameters were assumed at the values calculated at the level of theory as indicated above. Zaleski DP, Mullaney JC, Bittner DM, Tew DP, Walker NR, Legon AC(2015) Interaction of a pseudo-π C-C bond with cuprous and argentous chlorides: Cyclopropane⋅⋅⋅CuCl and cyclopropane⋅⋅⋅AgCl investigated by rotational spectroscopy and ab initio calculations. J Chem Phys 143(16):164314/1-164314/13 [http://dx.doi.org/10.1063/1.4934539]

444 CAS RN: MGD RN: 461952 MW augmented by ab initio calculations

Distances

Cyclopropane – copper(I) chloride (1/1) C3H6ClCu C2v Cu

r0 [Å] a

rs [Å] a

Cl

358

5 Molecules with Three Carbon Atoms

Cu–Cl Cu…X b C(2)–C(2) C(1)–C(2) C(2)–H C(1)–H

2.0612(42) 1.9912(46) 1.6177(9) 1.469(4) 1.0825(29) 1.0883(53)

Angles H–C(2)…X H–C(1)…X

θ0 [deg]

Dihedral angle H–C(2)…X…C(1)

θ0 [deg]

2.082(77)

118.94 c 122.34 c

104.49 c

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. X is the midpoint of C(2)–C(2). c Constrained to the value from CCSD(T)/aug-cc-pVTZ-F12 computation. b

The rotational spectra of the binary complex of cyclopropane with copper(I) chloride were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The complex was produced by a gas phase reaction of laser-ablated copper with tetrachloromethane and cyclopropane. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, 65 Cu, 37Cl, two D2, 37Cl/D2 and two 65Cu/D2); the remaining structural parameters were assumed at the values calculated at the level of theory as indicated above. Zaleski DP, Mullaney JC, Bittner DM, Tew DP, Walker NR, Legon AC(2015) Interaction of a pseudo-π C-C bond with cuprous and argentous chlorides: Cyclopropane⋅⋅⋅CuCl and cyclopropane⋅⋅⋅AgCl investigated by rotational spectroscopy and ab initio calculations. J Chem Phys 143(16):164314/1-164314/13 [http://dx.doi.org/10.1063/1.4934539]

445 CAS RN: 172655-70-8 MGD RN: 519080 GED combined with MW and augmented by QC computations

Bonds C(1)–C(2) C(2)–C(4) C(2)=N(3) C(1)–Cl C(1)–H(5) C(1)–H(4) C(4)–H(1) C(4)–H(2) C(4)–H(3) N(3)–O O–H

rg [Å] a,b 1.505(2) 1 1.503(2) 1 1.276(4) 1.803(3) 1.096(6) 2 1.091(6) 2 1.095(6) 2 1.100(6) 2 1.099(6) 2 1.401(4) 0.938(15)

(2Z)-1-Chloro-2-propanone oxime C3H6ClNO C1 (ac) HO

N Cl CH3

5 Molecules with Three Carbon Atoms

Bond angles C(1)–C(2)=N(3) C(2)–C(1)–Cl N(3)=C(2)–C(4) C(2)–C(1)–H(5) C(2)–C(1)–H(4) C(2)–C(4)–H(1) C(2)–C(4)–H(2) C(2)–C(4)–H(3) C(2)=N(3)–O N(3)–O–H

θα [deg] a,b

Dihedral angles N(3)=C(2)–C(1)–Cl N(3)=C(2)–C(1)–H(5) N(3)=C(2)–C(1)–H(4) Cl–C(1)–C(2)–C(4) N(3)=C(2)–C(4)–H(1) N(3)=C(2)–C(4)–H(2) N(3)=C(2)–C(4)–H(3) C(1)–C(2)=N(3)–O C(2)=N(3)–O–H

τα [deg]

359

122.9(16) 110.4(5) 119.5(13) 114.1(30) 3 115.4(30) 3 113.5(30) 3 113.6(30) 3 113.2(30) 3 114.0(8) 101.5 c

105.5 c -137.6 c -13.4 c -73.8 c -1.5 c 119.2 c -122.2 c -0.3 c -179.4 c

Reproduced with permission of SNCSC. a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/aug-cc-pVTZ computation. c Adopted from computation at the level of theory as indicated above. b

Two conformers, characterized by the anticlinal (ac) and antiperiplanar (ap) Cl–C–C=N dihedral angles, were predicted for the Z-isomer of chloropropanone oxime by MP2 and B3LYP computations; the ac conformer was predicted to be lower in energy than the ap conformer, whereas the Z-ac isomer is higher in energy than the E-ac isomer by about 6 kJ mol-1. Combined analysis of GED (Tnozzle= 343 K) and MW data revealed a mixture of the E-ac and Z-ac isomers in amounts of 68(4) and 32 %, respectively. Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, and rotational constants, ∆Bz= B0 – Bz, were calculated using quadratic force constants from MP2/6-31G(d,p) computation. Kuze N, Watado T, Takahashi Y, Sakaizumi T, Ohashi O, Kiuchi M, Iijima K (2015) Molecular structure and internal rotation of CH2Cl group of chloropropanone oxime: Gas electron diffraction, microwave spectroscopy, and quantum chemical calculation studies. Struct Chem 26 (5-6):1241-1257

446 CAS RN: 172655-75-3 MGD RN: 147672 GED combined with MW augmented by QC computations

Bonds C(1)–C(2) C(2)–C(4) C(2)=N(3) C(1)–Cl

rg [Å] a,b 1.499(2) 1 1.503(2) 1 1.276(4) 1.805(3)

(2E)-1-Chloro-2-propanone oxime C3H6ClNO C1 (ac) OH N Cl CH3

360

5 Molecules with Three Carbon Atoms

C(1)–H(5) C(1)–H(4) C(4)–H(1) C(4)–H(2) C(4)–H(3) N(3)–O O–H

1.096(6) 2 1.094(6) 2 1.098(6) 2 1.095(6) 2 1.098(6) 2 1.398(4) 0.938(15)

Bond angles C(1)–C(2)=N(3) C(2)–C(1)–Cl N(3)=C(2)–C(4) C(2)–C(1)–H(5) C(2)–C(1)–H(4) C(2)–C(4)–H(1) C(2)–C(4)–H(2) C(2)–C(4)–H(3) C(2)=N(3)–O N(3)–O–H

θα [deg] a,b

Dihedral angles N(3)=C(2)–C(1)–Cl N(3)=C(2)–C(1)–H(5) N(3)=C(2)–C(1)–H(4) Cl–C(1)–C(2)–C(4) N(3)=C(2)–C(4)–H(1) N(3)=C(2)–C(4)–H(2) N(3)=C(2)–C(4)–H(3) C(1)–C(2)=N(3)–O C(2)=N(3)–O–H

τα [deg] a

113.2(16) 111.1(5) 127.0(13) 114.8(30) 3 114.0(30) 3 113.3(30) 3 114.0(30) 3 113.4(30) 3 112.3(8) 101.8 c

121.1(21) -121.6 c 2.1 c -58.9 c 57.8 c 179.4 c -60.0 c 179.2 c 179.6 c

Reproduced with permission of SNCSC [1]. a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/aug-cc-pVTZ computation. c Adopted from computation at the level of theory as indicated above. b

Two conformers, characterized by the anticlinal (ac) and synperiplanar (sp) Cl–C–C=N torsional angles, were predicted for the E-isomer of chloropropanone oxime by MP2 and B3LYP computations. The ac conformer is predicted to be lower in energy than the sp one by up to 15 kJ mol-1. Furthermore, the E-ac isomer is estimated to be lower in energy than the Z-ac isomer by about 6 kJ mol-1. Combined analysis of GED (Tnozzle= 343 K) and MW data revealed a mixture of the E-ac and Z-ac isomers in amounts of 68(4) and 32 %, respectively. Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, and rotational constants, ∆Bz = B0 – Bz, were calculated using quadratic force constants from MP2/6-31G(d,p) computation. Kuze N, Watado T, Takahashi Y, Sakaizumi T, Ohashi O, Kiuchi M, Iijima K (2015) Molecular structure and internal rotation of CH2Cl group of chloropropanone oxime: Gas electron diffraction, microwave spectroscopy, and quantum chemical calculation studies. Struct Chem 26 (5-6):1241-1257

447 CAS RN: 594-20-7 MGD RN: 704966

2,2-Dichloropropane C3H6Cl2

5 Molecules with Three Carbon Atoms

361

MW augmented by ab initio calculations

C2v Cl

Bonds C–Cl C–C C–H C–H(1) C–H(2)

r0 [Å] a 1.797(3) 1.520(3) 1.090 b

r e [Å] a 1.7906(2) 1.5127(2)

Bond angles Cl–C–Cl C–C–C

θ0 [deg] a

θ see [deg] a

107.9(2) 113.4(3)

se

Cl

H 3C

CH3

1.0875 c 1.0898 c

108.14(2) 113.43(3)

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Assumed. c Adopted from CCSD(T)/aug-cc-pVTZ calculation. b

The rotational spectrum of 2,2-dichloropropane was recorded at room temperature by a broad-band millimeterwave spectrometer in the frequency region between 108 and 338 GHz and in a supersonic jet by a cavity FTMW spectrometer in the frequency region between 10 and 18.5 GHz. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 37Cl, se 37 Cl2 and 13C). The partial semiexperimental equilibrium structure r e was obtained taking into account rovibrational corrections calculated with the MP2/aug-cc-pVDZ harmonic and anharmonic (cubic) force fields. Białkowska-Jaworska E, Pszczółkowski L, Kisiel Z (2015) Comprehensive analysis of the rotational spectrum of 2,2-dichloropropane. J Mol Spectrosc 308:20-27

448 CAS RN: 1432474-61-7 MGD RN: 378530 MW augmented by QC calculations

1,1,3,3-Tetrafluoro-1,3-disilacyclopentane C3H6F4Si2 C2 F

Bonds C(1)–Si Si–C(2) C(2)–C(2ꞌ) Si–F(1) Si–F(2) C(1)–H C(2)–H(1) C(2)–H(2) Bond angles Si–C(1)–Siꞌ C(1)–Si–C(2) Si–C(2)–C(2ꞌ) C(1)–Si–F(1)

r0 [Å] a 1.8589(1) 1.8636(1) 1.5592(1) 1.5826(1) 1.5781(1) 1.0940(1) 1.0972(1) 1.0932(1)

θ0 [deg] a

102.78(2) 104.28(2) 106.60(2) 109.55(2)

rs [Å] a 1.860(13) 1.856(17) 1.5510(39)

θs [deg] a

102.21(63) 104.68(28) 106.47(22)

F

Si

Si

F F

362

5 Molecules with Three Carbon Atoms

C(1)–Si–F(2) C(2)–Si–F(1) C(2)–Si–F(2) F(1)–Si–F(2) H–C(1)–Si H–C(1)–H H(1)–C(2)–Si H(2)–C(2)–Si H(1)–C(2)–C(2ꞌ) H(2)–C(2)–C(2ꞌ) H(1)–C(2)–H(2)

113.41(2) 110.28(2) 112.72(2) 106.63(2) 111.29(2) 108.01(2) 108.37(2) 113.34(2) 109.63(2) 111.98(2) 106.86(2)

Dihedral angles C(2)–Si–C(1)–Siꞌ Si–C(2)–C(2ꞌ)–Siꞌ

τ0 [deg] a 10.67(2) 40.85(2)

τ0 [deg] a 41.71(42)

Copyright 2013 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of 1,1,3,3-tetrafluoro-1,3-disilacyclopentane was recorded by a supersonic-jet chirpedpulse FTMW spectrometer in the spectral range between 6.5 and 18 GHz. Only one conformer (twisted) was observed. The r0 structure was determined from the ground-state rotational constants of the six isotopic species (main, two 13 C, 29Si, 30Si and 29Si/30Si) in combination with the structural parameters from MP2_full/6-311+G(d,p) calculations. According to predictions of MP2_full and B3LYP calculations with various basis sets (up to aug-cc-pVTZ), the twisted conformer is the lowest energy conformer in comparison to the other ones with the envelope and planar ring. Pate BH, Seifert NA, Guirgis GA, Deodhar BS, Klaassen JJ, Darkhalil ID, Crow JA, Wyatt JK, Dukes HW, Durig J.R (2013) Microwave, infrared, and Raman spectra, structural parameters, vibrational assignments and theoretical calculations of 1,1,3,3-tetrafluoro-1,3-disilacyclopentane. Chem Phys 416:33-42

449 CAS RN: 31641-57-3 MGD RN: 153088 MW augmented by QC calculations

Dimethylphosphinous cyanide Cyanodimethylphosphine C3H6NP Cs H 3C

P

Bonds N≡C(1) C(1)–P P–C(2) C(2)–H(1) C(2)–H(2) C(2)–H(3)

r0 [Å] a 1.159(3) 1.790(3) 1.841(3) 1.0935(2) 1.0920(2) 1.0919(2)

Bond angles N≡C(1)–P C(1)–P–C(2) C(2)–P–C(3) P–C(2)–H(1)

θ0 [deg] a 175.7(5) 97.9(5) 100.7(5) 108.0(5)

H 3C

C

N

5 Molecules with Three Carbon Atoms

P–C(2)–H(2) P–C(2)–H(3) H(1)–C(2)–H(2) H(1)–C(2)–H(3) H(2)–C(2)–H(3)

112.5(5) 109.7(5) 109.3(5) 107.8(5) 109.3(5)

Dihedral angles C(1)–P–C(2)…C(3) N≡C(1)–P–C(2) C(1)–P–C(2)–H(1)

τ0 [deg] a

363

99.6(5) 128.9(5) 172.5(5)

Copyright 2012 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structural parameters were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of one isotopic species. The barrier to internal rotation of the methyl group was determined to be 2.42 kcal mol-1 from the methyl torsion frequency assigned from the IR spectrum of the solid. Panikar SS, Deodhar BS, Sawant DK, Klaassen JJ, Deng J, Durig JR (2013) Raman and infrared spectra, r0 structural parameters, and vibrational assignments of (CH3)2PX where X = H, CN, and Cl. Spectrochim Acta A 103:205-215

450 CAS RN: 151-18-8 MGD RN: 113109 MW augmented by ab initio calculations

Distances N(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)≡N(5) N(1)–H(1) N(1)–H(2) C(2)–H(3) C(2)–H(4) C(3)–H(5) C(3)–H(6) H(1)...C(4) H(2)...C(4) Bond angles N(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)≡N(5) H(1)–N(1)–H(2) H(1)–N(1)–C(2) H(2)–N(1)–C(2) H(3)–C(2)–N(1) H(4)–C(2)–C(3)

3-Aminopropanenitrile 2-Cyanoethylamine C3H6N2 C1 (Gg) C1 (Gꞌa)

Gg r0 [Å] a 1.461(3) 1.535(3) 1.466(3) 1.161(3) 1.014(3) 1.016(3) 1.093(2) 1.099(2) 1.094(2) 1.093(2) 3.884(5) 2.675(5)

Gꞌa r0 [Å] a 1.453(3) 1.545(3) 1.463(3) 1.161(3) 1.014(3) 1.015(3) 1.093(2) 1.094(2) 1.095(2) 1.095(2) 3.318(5) 2.727(5)

θ0 [deg] a

θ0 [deg] a

109.5(5) 111.1(5) 177.4(5) 107.1(5) 110.6(5) 110.5(5) 107.7(5) 108.8(5)

116.0(5) 111.1(5) 177.0(5) 107.6(5) 111.1(5) 111.2(5) 108.1(5) 107.8(5)

H 2N

C N

364

5 Molecules with Three Carbon Atoms

H(5)–C(3)–C(2) H(6)–C(3)–C(4) H(4)–C(2)–N(1) H(3)–C(2)–C(3) H(5)–C(3)–C(4) H(6)–C(3)–C(2) H(3)–C(2)–H(4) H(5)–C(3)–H(6) Dihedral angle N(1)–C(2)–C(3)–C(4)

110.7(5) 109.0(5) 114.9(5) 107.9(5) 107.8(5) 109.4(5) 107.7(5) 108.7(5)

110.0(5) 108.9(5) 108.5(5) 108.8(5) 108.3(5) 110.6(5) 107.3(5) 107.8(5)

τ0 [deg] a

τ0 [deg] a

-62.2(10)

58.2(10)

Copyright 2012 with permission from Elsevier.

a

Errors in parentheses in units of the last significant digit.

Gg

Gꞌa

The Gg and Gꞌa conformers characterized by the synclinal N–C–C–C torsional angles (G or Gꞌ) and differing in the orientation of the amino group defined by the synclinal (g) and antiperiplanar (a) lp–N–C–C torsional angles, respectively (lp is electron lone pair of the N atom), were predicted to be the lowest energy conformers by MP2 and B3LYP calculations with various basis sets (up to aug-cc-pVTZ). The r0 structural parameters of each of these conformers were obtained by fitting the MP2_full/6-311+G(d,p) structures to the three experimental ground-state rotational constants, which were published previously. Durig JR, Darkhalil ID, Klaassen JJ (2012) Infrared and Raman spectra, r0 structural parameters, conformational stability, and vibrational assignment of 2-cyanoethylamine. J Mol Struct 1023:154-162

451 CAS RN: 123-38-6 MGD RN: 691259 MW augmented by ab initio calculations

Propanal Propionaldehyde C3H6O Cs (syn) O

H3C

Bonds C(3)–C(2) C(3)–H(1) C(3)–H(2) C(2)–C(1) C(2)–H C(1)=O C(1)–H

r e [Å] a 1.5164(4) 1.0884(3) 1.0883(2) 1.5023(6) 1.0949(2) 1.2074(4) 1.1056(3) se

H

5 Molecules with Three Carbon Atoms

Bond angles C(2)–C(3)–H(1) C(2)–C(3)–H(2) H(1)–C(3)–H(2) H(2)–C(3)–H(2) C(1)–C(2)–C(3) C(3)–C(2)–H C(1)–C(2)–H H–C(2)–H C(2)–C(1)=O C(2)–C(1)–H O=C(1)–H

θ see [deg] a

Dihedral angles H(1)–C(3)–C(2)–H H(2)–C(3)–C(2)–H H(2)–C(3)–C(2)–C(1) H–C(2)–C(1)–H

τ e [deg] a -58.89(3) 61.66(4) 59.46(2) 56.23(2)

365

110.66(4) 110.72(2) 108.65(2) 107.32(3) 113.60(2) 111.75(3) 106.95(3) 105.35(4) 124.38(3) 115.44(3) 120.18(3) se

Copyright 2014 Wiley Periodicals, Inc.. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure of the syn conformer, characterized by the synperiplanar O=C–C–C torsional angle, was determined from the previously published ground-state rotational constants of twelve isotopic species taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. se The obtained r e structure confirmed the high accuracy of the CCSD(T)_ae/cc-pwCVTZ structure extrapolated to quadruple-ζ basis set. Vogt N, Demaison J, Vogt J, Rudolph HD (2014) Why it is sometimes difficult to determine the accurate position of a hydrogen atom by the semiexperimental method: structure of molecules containing the OH or the CH3 group. J Comput Chem 35(32):2333-2342

452 CAS RN: 107-18-6 MGD RN: 344631 MW augmented by QC calculations

2-Propen-1-ol Allyl alcohol C3H6O C1 (gauche-gauche) C1 (syn-gauche) OH

Bonds C(1)=C(2) C(2)–C(3) C(3)–O C(1)–H(5) C(1)–H(6) C(2)–H(7) C(3)–H(8) C(3)–H(9) O–H(4)

gauche-gauche r0 [Å] a 1.343(3) 1.499(3) 1.428(3) 1.087(2) 1.085(2) 1.089(2) 1.093(2) 1.098(2) 0.962(5)

syn-gauche r0 [Å] a 1.340(5) 1.504(5) 1.419(5) 1.085(2) 1.084(2) 1.089(2) 1.094(2) 1.099(2) 0.961(2)

H 2C

366

5 Molecules with Three Carbon Atoms

Bond angles C(1)=C(2)–C(3) C(2)–C(3)–O C(2)=C(1)–H(5) C(2)=C(1)–H(6) C(1)=C(2)–H(7) C(2)–C(3)–H(8) C(2)–C(3)–H(9) C(3)–O–H(4)

θ0 [deg] a

θ0 [deg] a

Dihedral angles C(2)–C(3)–O–H(4) C(1)=C(2)–C(3)–O

τ0 [deg] a

τ0 [deg] a

122.8(5) 112.1(5) 120.9(5) 121.7(5) 120.7(5) 110.8(5) 109.7(5) 106.6(5)

-54.3(5) 122.7(10)

124.7(5) 114.9(5) 120.8(5) 121.4(5) 119.8(5) 109.6(5) 108.8(5) 105.4(5)

57.7(5) 5.63(5)

Copyright 2009 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

gauche-gauche

syn-gauche

Five conformers were identified in the temperature-dependent IR vibrational spectra. These conformers, gauchegauche (Gg), syn-gauche (Sg), syn-anti (Sa), gauche-anti (Ga) and gauche-gaucheꞌ (Ggꞌ), are characterized by the different combinations of the synclinal (G) or synperiplanar (S) O-C-C=C dihedral angles with the synclinal (g) or antiperiplanar (a) C-C-O-H dihedral angles. The amounts of the Gg, Sg, Sa and Ga conformers were estimated for ambient temperature to be 54(2), 28(2), 8(2) and 11(3) %, respectively. The r0 structural parameters of the two most stable conformers, gauche-gauche and syn-gauche conformer were obtained by adjusting the MP2_full/6-311+G(d,p) structures to the previously published experimental groundstate rotational constants of five and two isotopic species, respectively. Durig JR, Ganguly A, El Defrawy AM, Zheng C, Badawi HM, Herrebout WA, van der Veken BJ, Guirgis GA, Gounev TK (2009) Conformational stability of allyl alcohol from temperature dependent infrared spectra of rare gas solutions, ab initio calculations, r0 structural parameters, and vibrational assignment. J Mol Struct 922:114126

453 CAS RN: MGD RN: 210143 MW supported by ab initio calculations

Thiobismethane – carbon monoxide (1/1) Dimethyl sulfide – carbon monoxide (1/1) C3H6OS Cs S

H 3C

Distance Rcm b

r0 [Å] a 3.493

Angles

θ0 [deg] a

φ

c

S…C(1)≡O

75.7 121.6

CH3

C

O

5 Molecules with Three Carbon Atoms

367

Copyright 2010 with permission from Elsevier.

a

Uncertainties were not given in the original paper. Distance between the centers of mass of monomer subunits. c Angle between the center-of-mass of the sulfide subunit, the S atom and the C(1) atom. b

The rotational spectrum of the binary complex was recorded by a pulsed supersonic beam FTMW spectrometer in the spectral region between 4.8 and 25 GHz. The partial r0 structure was obtained from the ground-state rotational constants of nine isotopic species (main, two 13C, 34S, 18O, 13C/34S, 13C/13C, 18O/34S, 18O/13C) under the assumption that the structural parameters were not changed upon complexation. Sato A, Kawashima Y, Hirota E (2010) Fourier transform microwave spectrum of the CO-dimethyl sulfide complex. J Mol Spectrosc 263(2):135-141

454 CAS RN: 109-94-4 MGD RN: 279828 MW supported by ab initio calculations

Formic acid ethyl ester Ethyl formate C 3H 6O 2 Cs (syn-anti) C1 (syn-gauche) O

Bonds C(1)=O(1) C(1)–O(2) O(2)–C(2) C(2)–C(3) Bond angles O(1)=C(1)–O(2) C(1)–O(2)–C(2) O(2)–C(2)–O(3)

syn-anti rs [Å] a 1.202(5) 1.317(1) 1.453(3) 1.511(6)

syn-gauche rs [Å] a 1.201(4) 1.37(2) 1.42(2) 1.510(6)

θs [deg] a

θs [deg] a

126.04(84) 115.31(31) 108.08(58)

H

O

CH3

125(2) 114(1) 111(1)

Copyright 2012 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit.

syn-anti

syn-gauche

The rotational spectra of the two lowest-energy conformers of ethyl formate were recorded by a chirped-pulse FTMW spectrometer in the frequency regions 6.5-18.5 and 25-40 GHz. Two conformers, syn-anti and syn-gauche, both with the synperiplanar O=C(1)–O(2)–C(2) torsional angle and differing by the antiperiplanar and synclinal C(1)–O(2)–C(2)–C(3) torsional angles, respectively, were detected.

368

5 Molecules with Three Carbon Atoms

The rs structure of the heavy-atom skeleton of each of these conformers was determined from the ground-state rotational constants of five isotopic species (main, three 13C and 18O). Zaleski DP, Neill JL, Muckle MT, Seifert NA, Carroll PB, Widicus Weaver SL, Pate BH (2012) A Ka-band chirped-pulse Fourier transform microwave spectrometer. J Mol Spectrosc 280:68-76

455 CAS RN: 56-52-5 MGD RN: 124935 MW augmented by QC calculations

Oxiranemethanol Glycidol C 3H 6O 2 Cs OH

Bonds C(2)–C(3) C(3)–O(2) C(3)–H(5) C(3)–H(4) C(2)–H(3) C(1)–C(2) C(1)–H(1) C(1)–H(2) C(1)–O(1) O(1)–H C(2)–O(2)

rs [Å] a 1.466 1.443

Bond angles O(2)–C(3)–C(2) C(2)–C(3)–H(4) C(2)–C(3)–H(5) C(3)–C(2)–H(2) C(3)–C(2)–C(1) C(2)–C(1)–H(1) C(2)–C(1)–H(2) C(2)–C(1)–O(1) C(1)–O(1)–H C(3)–O(2)–C(2)

θs [deg] a

Dihedral angles O(2)–C(2)–C(3)–H(4) O(2)–C(2)–C(3)–H(5) O(2)–C(3)–C(2)–H(2) O(2)–C(3)–C(2)–C(1) C(3)–C(2)–C(1)–H(1) C(3)–C(2)–C(1)–H(2) C(3)–C(2)–C(1)–O(1) C(2)–C(1)–O(1)–H

τs [deg] a

1.494 1.411 0.963

59.27

122.23 112.03 106.91

100.97 -30.80 -43.02

r e [Å] b 1.4612(12) 1.44214(64) 1.0813(12) 1.0807(12) 1.0845(12) 1.5064(16) 1.0947(12) 1.0894(12) 1.41019(78) 0.9633(19) 1.4289(14) c se

θ see [deg] b

58.963(75) 119.34(18) 118.71(19) 118.47(19) 121.58(10) 108.64(19) 109.83(19) 112.081(70) 105.76(18) 61.184(70) c

τ see [deg] b

102.50(30) -102.97(29) -102.71(31) 101.02(13) -151.30(29) 90.58(29) -28.48(26) -48.14(31)

Reprinted with permission. Copyright 2012 American Chemical Society

a

Uncertainties were not given in the original paper. Parenthesized uncertainties in units of the last significant digit. c Dependent parameter. b

O

5 Molecules with Three Carbon Atoms

369

The rotational spectra of the title compound were recorded by an FTMW spectrometer in the frequency region between 13 and 22 GHz. Two 18O isotopic species were studied in natural abundance. The rotational constants of the main, three 13C and one deuterated isotopic species were taken from the literature. The partial rs structure was obtained from the ground-state rotational constants of seven isotopic species. The se semiexperimental equilibrium structure r e was determined taking into account rovibrational corrections calculated with the B3LYP/6-311G** harmonic and anharmonic (cubic) force fields. Demaison J, Craig NC, Conrad AR, Tubergen MJ, Rudolph HD (2012) Semiexperimental equilibrium structure of the lower energy conformer of glycidol by the mixed estimation method. J Phys Chem A 116(36):9116-9122

456 CAS RN: 56-82-6 MGD RN: 146571 GED augmented by QC computations

2,3-Dihydroxypropanal Glyceraldehyde C 3H 6O 3 C1 (main conformer) O

Bonds C=O C(2)–O(5) C(3)–O(4) C(1)–C(2) C(2)–C(3) O–H C–H

r see [Å] a,b 1.214(4) 1.404(3) 1 1.410(3) 1 1.511(5) 2 1.522(5) 2 0.994(9) 3 1.122(9) 3

Bond angles C(1)–C(2)–C(3) C(2)–C(1)=O(6) C(1)–C(2)–O(5) C(2)–C(3)–O(4) C(3)–C(2)–O(5)

θ see [deg] a,b

Dihedral angles C(1)–C(2)–C(3)–O(4) C(3)–C(2)–C(1)=O(6) O(6)=C(1)–C(2)–O(5) O(5)–C(2)–C(3)–O(4) C(1)–C(2)–O(5)–H C(2)–C(3)–O(4)–H

τ see [deg]

HO

H OH

113.4(13) 120.7(5) 4 109.2(5) 4 110.0(7) 5 108.5(7) 5

59.9 c -126.7 d -5.7 e -61.6 d 9.5 e 53.8 e

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscript were refined in one group. Difference between parameters in each group was assumed at the value from MP2/cc-pVQZ computation. c Refined to be 65.7(58)°; in the final refinement, fixed at the value from computation as indicated above. d Dependent parameter. e Adopted from computation as indicated above. b

The GED experiment was carried out at Tnozzle = 388(10) K.

370

5 Molecules with Three Carbon Atoms

36 conformers with the energy differences up to 37.5 kJ mol−1 relative to the global minimum (conformer I) were predicted by B3LYP/cc-pVTZ computations. Five of these conformers (I-V), differing by the values of the torsional angles around the C1–C2, C2–C3, C2–O5 and C3–O4 bonds, were predicted to be present at the temperature of the experiment in the ratio I : II : III : IV : V = 63 : 18 : 4 : 9 : 5 (in %, MP2/cc-pVQZ). In the GED analysis, the mole fractions of the conformers I and II were determined to be 54(15) and 27(15) %, respectively, while the fractions of the other conformers were adopted from computation. Vibrational corrections to the experimental internuclear distances, ∆r see = ra − r see , were calculated from the MP2/cc-pVTZ quadratic and cubic force constants taking into account non-linear kinematic effects. Structural differences between the conformers were adopted from MP2/cc-pVQZ computation. Structural parameters are presented for conformer I. Vogt N, Atavin EG, Rykov AN, Popov EV, Vilkov LV (2009) Equilibrium structure and relative stability of glyceraldehyde conformers: Gas-phase electron diffraction (GED) and quantum-chemical studies. J Mol Struct 936 (1-3):125-131

457 CAS RN: 478920-42-2 MGD RN: 546068 MW augmented by ab initio calculations Distances C(1)–C(2) C(1)–O(1) O(1)–H O(1)...C(3) C(3)=O(2) C(3)=O(3)

Ethanol – carbon dioxide (1/1) C 3H 6O 3 Cs H 3C

OH

O

C

O

r e [Å] a 1.49(4) 1.41(5) 0.89(4) 2.79(4) 1.15(6) 1.16(6) se

Reprinted with permission. Copyright 2017 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the binary complex ethanol with carbon dioxide were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 5 and 26 GHz. The semiexperimental equilibrium structure was determined from the ground-state rotational constants of six isotopic species (main, three 13C, 18O and D) taking into account rovibrational corrections calculated with the MP2/aug-cc-pVDZ harmonic and anharmonic (cubic) force fields. McGuire BA, Martin-Drumel MA, McCarthy MC (2017) Electron donor-acceptor nature of the ethanol-CO2 dimer. J Phys Chem A 121(33):6283-6287

458 CAS RN: 870-23-5 MGD RN: 111640 MW augmented by QC calculations

2-Propene-1-thiol Allyl mercaptan C 3H 6S C1 SH H 2C

Bonds

r0 [Å] a

5 Molecules with Three Carbon Atoms

C(1)–C(2) C(2)=C(3) C(1)–S S–H C(1)–H(1) C(1)–H(2) C(2)–H C(3)–H(3) C(3)–H(4)

1.496(3) 1.343(3) 1.827(3) 1.335(3) 1.094(2) 1.092(2) 1.088(2) 1.084(2) 1.087(2)

Bond angles C(2)–C(1)–S C(1)–C(2)=C(3) C(1)–S–H S–C(1)–H(1) S–C(1)–H(2) C(2)–C(1)–H(1) C(2)–C(1)–H(2) C(1)–C(2)–H C(3)=C(2)–H C(2)=C(3)–H(3) C(2)=C(3)–H(4) H(1)–C(1)–H(2)

θ0 [deg] a

Dihedral angles C(3)=C(2)–C(1)–S C(2)–C(1)–S–H

τ0 [deg] a

371

112.5(5) 123.4(5) 95.1(5) 104.4(5) 110.0(5) 110.8(5) 110.7(5) 116.5(5) 120.2(5) 121.3(5) 121.2(5) 108.1(5)

118.7(5) -54.6(5)

Copyright 2011 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded by an FTMW spectrometer in the frequency region between 10 and 22 GHz. The rotational constants were determined only for the most abundant conformer, characterized by the anticlinal C(3)=C(2)–C(1)–S and synclinal C(2)–C(1)–S–H torsional angles (denoted as Gg). Three other conformers, characterized by the synperiplanar (S) or synclinal (G) C(3)=C(2)–C(1)–S torsional angle and the synclinal (g) or anticlinal (a) C(2)-C(1)-S-H torsional angle and denoted as Sg, Ggꞌ and Ga, were estimated to be present by temperature-dependent IR vibrational spectroscopy in amounts of 29(1), 10(1) and 9(1) % (at ambient temperature), respectively. The r0 structure was determined from the ground-state rotational constants of the main isotopic species combined with structural parameters from MP2_full/6-311+G(d,p) calculations. Durig JR, Klaassen JJ, Deodhar BS, Gounev TK, Conrad AR, Tubergen MJ (2012) Microwave, infrared, and Raman spectra, r0 structural parameters, conformational stability, and vibrational assignment of allylthiol. Spectrochim Acta A 87:214-227

459 CAS RN: 1072-43-1 MGD RN: 600410 GED augmented by ab initio computations

2-Methylthiirane Propylene sulfide C 3H 6S C1 S

Distances

rh1 [Å] a

ra [Å] a

CH3

372

5 Molecules with Three Carbon Atoms

C–C C(3)–S C(2)–S C–H C(2)–C(3) C(2)–C(1) C(3)…C(1) S...C(1)

1.500(2) b,c 1.832(2) 1.832(2) 1.057(3) b

Bond angles C(1)–C(2)–H C(2)–C(1)–H H–C(3)–H C(2)–C(3)–S C(3)–C(2)–S C(2)–S–C(3) C(1)–C(2)–C(3) C(1)–C(2)–S

θh1 [deg] a

Dihedral angles C(3)–C(2)–C(1)–H(1) S–C(3)–C(2)–C(1) S–C(3)–C(2)–H C(2)–S–C(3)–H(2)

τh1 [deg] a

1.831(2) 1.831(2) 1.052(3) b 1.495(18) 1.502(19) 2.560(8) 2.885(4)

111.1(15) 109.6(16) 116.4(10) 65.9(3) d 65.9(3) d 48.2(6) d 117.3(6) d 119.5(11)

27.4(31) 112.0(15) -109.1(20) 113.6(26)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Average value. c Difference between the C–C bond lengths was determined to be 0.005(40) Å. d Dependent parameter. b

The GED experiment was carried out at Tnozzle ≈296 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from HF/6-311+G(d,p) calculation. The molecule was found to possess a relatively long C–S bond and a small C–S–C angle. Aarset K, Page EM, Rice DA (2011) The molecular structure of propylene sulphide (methylthiirane) by gasphase electron diffraction and theoretical calculations: A molecule used in MOCVD. J Mol Struct 1002 (1-3):1923

460 CAS RN: 23118-84-5 MGD RN: 374101 GED supported by QC computations

Bonds Si–C C–C Si–Br

1-Bromosilacyclobutane C3H7BrSi Cs (axial) Cs (equatorial)

axial 1.872(3) 1.583(6) 2.225(3)

ra [Å] a equatorial 1.869(3) 1.583(6) 2.212(3)

H Si

Br

5 Molecules with Three Carbon Atoms

Si–H C–H Bond angles H–Si–Br C–Si–C C–C–Si C–C–C H–C(3)–H Si–C(2)–H(5) Si–C(2)–H(6) C(3)–C(2)–H(5) C(3)–C(2)–H(6) Dihedral angle

ϕ

d

1.477 b 1.101(12) c axial 107.0(15) 79.4 b 92.3(36) 100.2 b 108.13 b 126.5(48) 95.9(60) 125.0(15) 104.4(50)

axial 28.8(52)

373

1.477 b 1.101(12) c

θa [deg] a

equatorial 107.0(15) 79.4 b 90.9(32) 100.2 b 107.97 b 126.5(48) 96.6(60) 125.0(15) 104.4(50)

axial

τa [deg] a

equatorial 39.9(33)

Copyright 2010 with permission of Elsevier. a

Parenthesized uncertainties in units of the last significant digit are 3σ values. b Adopted from computation at the level of theory as indicated below. c Average value. d Ring puckering angle.

equatorial

The GED experiment was carried out at the nozzle temperature of 300 K. The title compound was found to exist as a mixture of two conformers, characterized by the axial and equatorial positions of the bromine atom, with a significantly higher prevalence of the later form. The determined ratio of the conformers, equatorial : axial = 73(6) : 29(6) (in %), corresponds to the energy difference of 0.59(5) kcal mol−1. This value is in a good agreement with prediction of 0.55 kcal mol−1 (equatorial : axial = 71.4 : 28.6 %) at the MP2/6-311++G(df,pd) level of theory. Simple relationship between the puckering angle ϕ and the puckering amplitude q was emerged as follows: ϕ / q = ρ, where the constant ρ = 98(1) Å-1 for all mono- and dihaloginated silacyclobutanes. Dakkouri M, Novikov VP, Vilkov LV (2010) A gas-phase electron diffraction and quantum chemical investigation of the molecular structure of 1-bromosilacyclobutane. J Mol Struct 978 (1-3):234-245

461 CAS RN: 123201-65-0 MGD RN: 123594 MW augmented by QC calculations

(Fluorosilyl)cyclopropane Cyclopropylfluorosilane C3H7FSi C1 (gauche) F

Bonds Si–C(2) C(2)–C(4) C(2)–C(5) C(4)–C(5) Si–F C(2)–H(3) C(4)–H(6) C(4)–H(7)

a

r0 [Å] 1.836(3) 1.524(3) 1.518(3) 1.500(3) 1.594(3) 1.086(2) 1.085(2) 1.083(2)

Si H2

374

5 Molecules with Three Carbon Atoms

C(5)–H(8) C(5)–H(9) Si–H(1) Si–H(2)

1.085(2) 1.083(2) 1.480(3) 1.482(3)

Bond angles Si–C(2)–H(3) C(2)–C(4)–C(5) C(2)–C(5)–C(4) C(4)–C(2)–C(5) Si–C(2)–C(4) Si–C(2)–C(5) C(2)–Si–F H(6)–C(4)–H(7) H(8)–C(5)–H(9) C(2)–Si–H(1) C(2)–Si–H(2) F–Si–H(1) F–Si–H(2) H(1)–Si–H(2)

θ0 [deg] a

Dihedral angle H(3)–C(2)–Si–F

τ0 [deg] a

117.7(5) 60.3(5) 60.7(5) 59.1(5) 117.6(5) 119.2(5) 111.2(5) 114.8(5) 114.9(5) 112.4(5) 108.4(5) 106.4(5) 107.4(5) 111.1(5)

64.8(5)

Copyright 2013 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the spectral range between 11 and 22 GHz. Only the gauche conformer characterized by the synclinal H(3)–C(2)–Si–F torsional angle was observed. The r0 structure was determined from the ground-state rotational constants of the three isotopic species (main, 29 Si and 30Si) combined with structural parameters predicted by MP2_full/6-311+G(d,p) calculation. The B3LYP calculations predict the gauche conformer to be more stable than the anti one (with the antiperiplanar H(3)–C(2)–Si–F torsional angle), whereas the anti conformer is more stable according to results of MP2 calculations. The abundance of anti conformer was determined to be 23(2) % (at room temperature) by the analysis of IR vibrational spectra. Panikar SS, Guirgis GA, Eddens MT, Dukes HW, Conrad AR, Tubergen MJ, Gounev TK, Durig JR (2013) Microwave, infrared and Raman spectra, adjusted r0 structural parameters, conformational stability, and vibrational assignment of cyclopropylfluorosilane. Chem Phys 415:124-132

462 CAS RN: 79-46-9 MGD RN: 652720 GED augmented by QC computations

Bonds C–H N=O(2) N=O(1) C–N

2-Nitropropane C3H7NO2 Cs NO2

re [Å] a,b 1.101(12) c 1.226(4) 1 1.225(4) 1 1.501(5) 2

H 3C

CH3

5 Molecules with Three Carbon Atoms

C–C

1.516(5) 2

Bond angles C–C–N C–C–C C–N=O(2) C–N=O(1) O=N=O C–C–H

θe [deg] a

375

108.7(10) 112.8(11) 118.0(4) d 117.2(4) d 124.8(4) 110.1(3)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscript were refined in one group. Difference between parameters in each group was assumed at the value from MP2/6-311G* computation. c Average value. d Dependent parameter. b

For the title molecule, MP2 and B3LYP computations with various Pople and Dunnig basis sets predicted syn-H equilibrium configuration (with the H−C−N=O dihedral angle equal to zero) and relatively low barrier to internal rotation of the nitro group (375-525 cm−1) pointing to hindered rotation of this group. The GED experiment was carried out at Tnozzle = 292 K. In the GED analysis, the large-amplitude motion of the nitro group was described by the model of pseudoconformers, the barrier to internal rotation was determined to be 220-560 cm−1 with the most probable value of 380 cm−1 (1.1 kcal mol−1). Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with the scaled quadratic and cubic force constants from MP2/6-311G* computation taking into account non-linear kinematic effects. Tarasov YI, Kochikov IV, Kovtun DM, Ivanov AA (2009) Internal rotation and equilibrium structure of 2nitropropane from gas electron diffraction and quantum chemistry. J Mol Struct 921(1-3):255-263 463 CAS RN: 56-41-7 MGD RN: 688857 MW augmented by ab initio calculations

L-Alanine (2S)-2-Aminopropanoic acid C3H7NO2 C1 (I) C1 (IIa) O

Bonds C(1)–C(2) C(2)–C(3) C(2)–N C(1)=O(1) C(1)–O(2) N–H b Bond angles C(1)–C(2)–C(3) C(1)–C(2)–N C(2)–C(1)=O(1) O(1)–C(1)–O(2) C(1)–O(2)–H

I se r e [Å] a 1.520(3) 1.522(4) 1.448(4) 1.207(7) 1.349(6) 1.014(4)

IIa se r e [Å] a 1.530(3) 1.529(4) 1.460(4) 1.205(9) 1.33(1)

θ see [deg] a

θ see [deg] a

109.0(3) 113.3(4) 125.1(4) 122.7(2) 105.9(6)

108.2(3) 109.8(4) 122.0(8) 123.2(4)

H 3C

OH NH2

376

5 Molecules with Three Carbon Atoms

C(1)–C(2)–H

106.5(5)

Dihedral angles O(1)=C(1)–C(2)–N O(2)–C(1)–C(2)–C(3) O(2)–C(1)–C(2)–H

τ e [deg] a -16.2(8) -71.9(4) 47.5(9) se

τ e [deg] a -192.5(5) -254.5(4) se

Reprinted with permission. Copyright 2010 American Chemical Society. a b

Parenthesized uncertainties in units of the last significant digit. Average.

I

IIa se

The semiexperimental equilibrium structure r e of each of two lowest-energy conformers, I and IIa, was determined from previously published ground-state rotational constants of ten isotopic species taking into account rovibrational corrections calculated with the MP2/6-31G(d) quadratic and cubic force fields. These conformer were predicted to be almost isoenergetic: the conformer IIa is higher in energy than the conformer I by only 0.58 kJ mol-1 (CCSD(T)/CBS). Jaeger HM, Schaefer HF, Demaison J, Császár AG, Allen WD (2010) Lowest-lying conformers of alanine: Pushing theory to ascertain precise energetics and semiexperimental re structures. J Chem Theory Comput. 6(10):3066-3078 464 CAS RN: 81637-99-2 MGD RN: 148380 GED augmented by ab initio computations

Bonds P–C P–H C(1)–C(2) C(2)=C(3) C–H Bond angles H–P–H C–P–H P–C–C C–C=C H–C–H C(2)=C(3)–H C(3)=C(2)–H C(2)–C(1)–H

I 1.875(1) b 1.422(15) c 1.521(4) b 1.357(7) b 1.087(3) c

I 94.2(10) b 96.9(10) c 114.0(2) b 122.9(8) c 106.1(10) c,d 121.4(9) c,d 119.8(9) c,d 109.8(7) c,d

2-Propenylphosphine Allylphosphine C3H7P C1 (I) C1 (II) C1 (III)

rh1 [Å] a II 1.880(2) b 1.422(15) c 1.524(4) b 1.357(7) b 1.087(3) c

θh1 [deg] a

II 94.2(10) b 96.7(10) c 109.3(10) b 122.9(8) c 106.1(10) c,d 121.4(9) c,d 119.8(9) c,d 109.8(7) c,d

H 2C

III 1.877(1) b 1.422(15) c 1.524(4) b 1.357(7) b 1.087(3) c I

III 94.9(10) b 96.9(10) c 108.9(5) b 122.9(8) c 106.1(10) c,d 121.4(9) c,d 119.8(9) c,d 109.8(7) c,d

II

PH2

5 Molecules with Three Carbon Atoms

Dihedral angles C=C–C–P X…P–C–C e

I 112.1(10) d 2.1(10) d

377

τh1 [deg] a

II 106.5(15) d 112.0(15) d

III 111.9(15) d -123.8(15) d

Reprinted with permission. Copyright 2009 American Chemical Society [a].

III

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Structural differences between the conformers were restrained to the values from MP2/6-311++G** computation. c Average value. d Restrained to the value from computation as indicated above. e X is the bisector of the H–P–H angle. b

The GED experiment was carried out at the nozzle temperatures of 225 and 230 K at the long and short nozzleto-film distances, respectively. MP2 computations predicted five conformers characterized by various combinations of the C=C–C–P and H–P– C–C torsional angles (see also Ref. [b]). In the three lowest energy conformers, I, II and III, the C=C–C–P torsional angle is anticlinal, whereas it is synperiplanar in the two higher energy conformers. The conformers I, II and III were predicted to be present at the temperature of the GED experiment. The ratio of the conformers II/III could not be determined in the GED analysis. Therefore, it was assumed at the value of 0.5 adopted from computation. The amount of the conformer I was determined to be 79(4)%. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force field from MP2/6-311++G** computations. a. Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612 b. Møllendal H, Demaison J, Guillemin J-C (2002) Structural and conformational properties of 2propenylphosphine (allylphosphine) as studied by microwave spectroscopy supplemented by quantum chemical calculations. J Phys Chem A 106 : 11481-11482

465 CAS RN: 88394-66-5 MGD RN: 316748 GED augmented by QC computations

1-Azido-N,N-dimethylmethanamine C3H8N4 C1 (anti-gauche)

Bonds N(1)–C(2) C(2)–N(3) N(3)=N(4) N(4)≡N(5)

rh1 [Å] a,b 1.426(2) 1 1.511(2) 1 1.232(2) 2 1.154(2) 2

Bond angles N(3)–C(2)–N(1) N(4)=N(3)–C(2) N(5)≡N(4)=N(3)

θh1 [deg] a

Dihedral angles C(6)–N(1)–C(2)–N(3)

τh1 [deg]

115.1 c 116.2(13) 179.5(28)

-63.0 c

378

5 Molecules with Three Carbon Atoms

N(4)=N(3)–C(2)–N(1) C(7)–N(1)–C(2)–N(3) N(5)≡N(4)=N(3)–C(2)

-89.3 c 64.5 c -170.6 c

Copyright 2013 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Bond lengths with equal superscripts were refined in the same group; differences between parameters in each group were fixed at the values from MP2/6-311+G(d,p) computation. c Assumed at the value from computation as above. b

The GED experiment was carried out at Tnozzle = 294 K. The best fit to the experimental intensities was obtained for the model of three conformers, anti-gauche (70 %), anti-anti (12 %) and gauche-gauche (18 %), characterized by the antiperiplanar or synclinal lp–N(1)–C(2)–N(3) and N(4)=N(3)–C(2)–N(1) torsional angles (lp is the electron lone pair of the N(1) atom). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated from the MP2/6-311+G(d,p) harmonic force constants. Structural parameters were presented for the predominant conformer (anti-gauche). Altova EP, Nabiev OG, Karasev NM, Kostyanovsky RG, Khaikin LS, Shishkov IF (2013) Molecular structure of N-azidomethyl-N,N-dimethylamine according to gas-phase electron diffraction data and quantum-chemical calculations. Mendeleev Commun 23 (3):166-167

466 CAS RN: 82748-81-0 MGD RN: 442311 MW supported by ab initio calculations

Distances Rcm b S(2)…C(1)

Formaldehyde – thiobismethane (1/1) Formaldehyde – dimethyl sulfide (1/1) C3H8OS Cs

r0 [Å] a 3.200 3.02

Reprinted with permission. Copyright 2009 American Chemical Society

a b

Uncertainties were not given in the original paper. Distance between centers of mass in both monomer subunits.

The rotational spectrum of the binary complex of formaldehyde with dimethyl sulfide was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 9 and 20 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D2) under the assumption that the structural parameters were not changed upon complexation. Tatamitani Y, Kawashima Y, Osamura Y, Hirota E (2015) Intermolecular interaction in the formaldehydedimethyl ether and formaldehyde-dimethyl sulfide complexes investigated by Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 119(10):2132-2141

467 CAS RN: 1659263-79-2 MGD RN: 442490

Formaldehyde – oxybismethane (1/1) Formaldehyde – dimethyl ether (1/1) C 3H 8O 2

5 Molecules with Three Carbon Atoms

379

MW supported by ab initio calculations

Cs O O H 3C

Distances Rcm b O(2)…C(1)

CH3

H

H

r0 [Å] a 3.102 2.90

Reprinted with permission. Copyright 2009 American Chemical Society

a b

Uncertainties were not given in the original paper. Distance between centers of mass in both monomer subunits.

The rotational spectra of the binary complex of formaldehyde with dimethyl ether were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 9 and 20 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D2) under the assumption that the structural parameters were not changed upon complexation. Tatamitani Y, Kawashima Y, Osamura Y, Hirota E (2015) Intermolecular interaction in the formaldehydedimethyl ether and formaldehyde-dimethyl sulfide complexes investigated by Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 119(10):2132-2141

468 CAS RN: 866344-09-4 MGD RN: 489506 MW augmented by ab initio calculations

Oxybismethane – formic acid (1/1) Dimethyl ether – formic acid (1/1) C 3H 8O 3 Cs O

O H 3C

a

Distances O(6)…H(5) O(2)..H(4)

r0 [Å] 1.673 2.824

Angles O(6)…H(5)–O(3) C(8)–H(4)…O(2) X…O(6)…H(5) b C(1)–O(2)…H(4)

θ0 [deg] a

CH3 H

OH

179.9 115.5 128.0 112.5

Reprinted with permission. Copyright 2016 American Chemical Society

a b

Uncertainties were not given in the original paper. X is a dummy atom placed on the bisector of the C(8)–O(6)–C(9) angle.

The rotational spectrum of the binary complex of dimethyl ether with formic acid was recorded in a supersonic jet by an FTMW spectrometer in the region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, two 13C and two D); the remaining structural parameters were constrained to the value from MP2/6-311++G(d,p) calculations.

380

5 Molecules with Three Carbon Atoms

Evangelisti L, Spada L, Li W, Ciurlini A, Grabow JU, Caminati W (2016) Shape of the adduct formic aciddimethyl ether: A rotational study. J Phys Chem A 120(18):2863-2867

469 CAS RN: MGD RN: 159032 MW augmented by ab initio calculations

Distance Rcm b

2-Oxiranemethanol – water (1/1) Glycidol – water (1/1) C 3H 8O 3 C1 OH O

a

r0 [Å] 2.888(2)

O H

H

Dihedral and other angles τ0 [deg] a 87.6(15) ϕ1 c 130.8(5) ϕ2 d -114.8(4) ϕe H–O(1)–C(1)–C(2) -65(5) O(1)–C(1)–C(2)–O(2) 49.9 f Reprinted with permission. Copyright 2009 American Chemical Society

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Tilt angle of the water subunit with respect to intermolecular axis. d Tilt angle of the glycidol subunit with respect to intermolecular axis. e Twist angle of the glycidol subunit about the axis joining the H(1) atom to the glycidol center-of-mass. f Constrained to ab initio value. b

The rotational spectrum of the binary complex of glycidol with water was recorded in a supersonic jet by a cavity-based FTMW spectrometer. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 18 O, D and D2). Conrad AR, Teumelsan NH, Wang PE, Tubergen MJ (2010) A spectroscopic and computational investigation of the conformational structural changes induced by hydrogen bonding networks in the glycidol-water complex. J Phys Chem A 114(1):336-342

470 CAS RN: 287-29-6 MGD RN: 727390 MW augmented by ab initio calculations

Silacyclobutane C3H8Si Cs SiH2 a

a

Bonds Si–C(2) C(2)–C(3)

r0 [Å] 1.8848(8) 1.5646(21)

rs [Å] 1.879(6) 1.567(5)

Bond angles C(2)–Si–C(2') Si–C(2)–C(3)

θ0 [deg] a

θs [deg] a

79.10(4) 86.28(6)

79.4(5) 86.4(9)

5 Molecules with Three Carbon Atoms

381

C(2)–C(3)–C(2')

100.18(18)

100.0(5)

Dihedral angle C(2')–Si–C(2)–C(3)

τ0 [deg] a

τs [deg] a

-19.891(23) 31.1(4)

φb

30.5(36)

Reprinted with permission. Copyright 2011 American Chemical Society

a b

Parenthesized uncertainties in units of the last significant digit. Puckering angle is defined as deviation of the angle between the C–C–C and C–Si–C planes from 180°.

The rotational spectra of silacyclobutane were recorded in a supersonic jet both by a chirped-pulse FTMW and a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 24 GHz. The r0 structure of the heavy-atom skeleton was determined from the ground-state rotational constants of five isotopic species (main, 29Si, 30Si and two 13C); the structural parameters involving H atoms were fixed at ab initio values. The rs structure of the heavy-atom skeleton was also derived. van Wijngaarden J, Chen Z, van Dijk CW, Sorensen JL (2011) Pure rotational spectrum and ring inversion tunneling of silacyclobutane. J Phys Chem A 115(31):8650-8655 471 CAS RN: 57519-90-1 MGD RN: 515400 GED augmented by ab initio computations

Bonds Si–Si Si–C Si–Br C–H

rh1 [Å] a 2.348(2) b 1.892(1) 2.212(1) 1.088(3)

Bond angles Si–Si–Br Si–Si–C Si–C–H c

θh1 [deg] a

Dihedral angle Br(1)–Si–Si–C(3)

τh1 [deg]

1,1,1-Tribromo-2,2,2-trimethyldisilane C3H9Br3Si2 C3v

111.2(1) 108.8(2) b 111.1(4) b

-60.0 d

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Restrained to the value from MP2/6-311+G* computation. c Average. d Fixed at the value from computation as indicated above. b

The experiments were carried out at Tnozzle = 351 K. The molecule was determined to adopt the staggered conformation.

382

5 Molecules with Three Carbon Atoms

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from HF/6-31G* computation. Atkinson SJ, Robertson HE, Hölbling M, du Mont WW, Mitrofan C, Hassler K, Masters SL (2013) Do halogen and methyl substituents have electronic effects on the structures of simple disilanes? An experimental and theoretical study of the molecular structures of the series X3SiSiMe3 (X = H, F, Cl and Br). Struct Chem 24 (3):851-857

472 CAS RN: 18026-87-4 MGD RN: 515215 GED augmented by ab initio computations

Bonds Si–Si Si–C Si–Cl C–H

rh1 [Å] a 2.334(2) 1.872(2) 2.048(1) 1.077(3) b

Bond angles Si–Si–Cl Si–Si–C Si–C–H c

θh1 [deg] a

Dihedral angle Cl(1)–Si–Si–C(3)

τh1 [deg]

1,1,1-Trichloro-2,2,2-trimethyldisilane C3H9Cl3Si2 C3v

111.8(1) 107.0(2) b 111.0(3) b

-60.0 d

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Restrained to the value from MP2/6-311+G* computation. c Average. d Adopted from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle = 293 K. The molecule was determined to adopt the staggered conformation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from HF/6-31G* computation. Atkinson SJ, Robertson HE, Hölbling M, du Mont WW, Mitrofan C, Hassler K, Masters SL (2013) Do halogen and methyl substituents have electronic effects on the structures of simple disilanes? An experimental and theoretical study of the molecular structures of the series X3SiSiMe3 (X = H, F, Cl and Br). Struct Chem 24 (3):851-857

473 CAS RN: 64809-82-1 MGD RN: 515031 GED augmented by ab initio computations

1,1,1-Trifluoro-2,2,2-trimethyldisilane C3H9F3Si2 C3v

5 Molecules with Three Carbon Atoms

Bonds Si–Si Si–C Si–F C–H

rh1 [Å] a 2.335(2) b 1.880(1) 1.581(1) 1.105(2)

Bond angles Si–Si–F Si–Si–C Si–C–H c

θh1 [deg] a

Dihedral angle F(1)–Si–Si–C(3)

τh1 [deg]

383

112.0(1) 108.9(3) 111.8(4) b

-60.0 d

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Restrained to the value from MP2/6-311+G* computation. c Average. d Adopted from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle = 293 K. The molecule was determined to adopt the staggered conformation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from HF/6-31G* computation. Atkinson SJ, Robertson HE, Hölbling M, du Mont WW, Mitrofan C, Hassler K, Masters SL (2013) Do halogen and methyl substituents have electronic effects on the structures of simple disilanes? An experimental and theoretical study of the molecular structures of the series X3SiSiMe3 (X = H, F, Cl and Br). Struct Chem 24 (3):851-857

474 CAS RN: 75-31-0 MGD RN: 340379 MW augmented by QC calculations

2-Propanamine Isopropylamine C 3H 9N Cs NH2

Bonds N(1)–C(2) C(2)–C(4) C(2)–C(5) N(1)–H(1) N(1)–H(2) C(2)–H(3) C(4)–H

r0 [Å] a 1.465(3) 1.530(3) 1.530(3) 1.019(3) 1.019(3) 1.102(2) 1.094(2)

Bond angles N(1)–C(2)–C(4) N(1)–C(2)–C(5) C(4)–C(2)–C(5)

θ0 [deg] a 108.9(5) 108.9(5) 111.0(5)

H 3C

CH3

384

5 Molecules with Three Carbon Atoms

H(1)–N(1)–H(2) C(2)–N(1)–H(1) C(2)–N(1)–H(2) N(1)–C(2)–H(3) H(3)–C(2)–C(4) H(3)–C(2)–C(5) C(2)–C(5)–H(4) C(2)–C(5)–H(5) C(2)–C(5)–H(6) H(4)–C(5)–H(5) H(5)–C(5)–H(6) H(4)–C(5)–H(6)

106.9(5) 110.3(5) 110.3(5) 112.1(5) 108.0(5) 108.0(5) 109.7(5) 111.0(5) 110.8(5) 108.3(5) 108.0(5) 109.0(5)

Dihedral angles H(1)–N(1)–C(2)–H(3) H(2)–N(1)–C(2)–H(3) H(9)–C(5)–C(2)–N(1) H(4)–C(5)–C(2)–N(1)

τ0 [deg] a 59.0(5) -59.0(5) 59.8(5) -59.8(5)

Copyright 2011 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last digit.

Both the anti and gauche conformers with the antiperiplanar and synclinal lp–N–C–H torsional angles, respectively (lp is the electron lone pair on N), were identified in the temperature-dependent Raman and IR vibrational spectra. The percentage of the gauche conformer was estimated to be 54(1) % at ambient temperature. The r0 structural parameters were determined for the anti conformer by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of two isotopic species. Durig JR, Klaassen JJ, Darkhalil ID, Herrebout WA, Dom JJJ, van der Veken BJ (2012) Conformational and structural studies of isopropylamine from temperature dependent Raman spectra of xenon solutions and ab initio calculations. J Mol Struct 1009:30-41

475 CAS RN: MGD RN : 209445 MW augmented by ab initio calculations

2-Oxiranemethanol – ammonia (1/1) Glycidol – ammonia (1/1) C3H9NO2 C1 OH

O

Distances N⋅⋅⋅O(2) N⋅⋅⋅H(2) O(1)⋅⋅⋅H(1) Angles N⋅⋅⋅O(2)–C H–N⋅⋅⋅H(2) Dihedral angles

r0 [Å] a gauche1 gauche2 2.880(1) 2.888(1) 1.916 b 1.917 b b 2.267 2.271 b

θ0 [deg] a

gauche1 102.4(1) 94(1)

gauche2 101.4(1) 99.5(1)

τ0 [deg] a

N H

H H

5 Molecules with Three Carbon Atoms

gauche1 71.4(1) 11(5)

N⋅⋅⋅O(2)–C–C H–N⋅⋅⋅H(2)–O(2)

385

gauche2 -65.1(1) -4(3)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

gauche1

gauche2

The rotational spectrum of the title complex was recorded in a pulsed supersonic jet by an FTMW spectrometer in the frequency region between 6 and 18.5 GHz. Two conformers, gauche1 and gauche2, characterized by different N...O(2)–C–C torsional angles, were identified. The partial r0 structure was determined from ground-state rotational constants of two isotopic species (main and 15 N); the remaining structural parameters were assumed at the values from MP2_full/6-311++G** calculations. The V3 barrier to internal rotation of the NH3 group about its C3 axis was determined to be 3.522(2) and 2.270(1) kJ mol-1 for the gauche1 and gauche2 conformers, respectively. Giuliano BM, Melandri S, Maris A, Favero LB, Caminati W (2009) Adducts of NH3 with the conformers of glycidol: A rotational spectroscopy study. Angew Chem 121(6):1122-1125; Angew Chem Int Ed 48(6):11021105

476 CAS RN: 1449-63-4 MGD RN: 763456 GED augmented by QC computations

Bonds C−H Ge−C Ge−H

rh1 [Å] a 1.108(2) 1.9467(4) 1.544(4)

Bond angles Ge−C−H H–Ge–C C−Ge−C

θh1 [deg] a

Other angle tilt(CH3)

τh1 [deg] a

110.8(2) 108.7(1) 110.2(1) b

0.5(8) c

Reprinted with permission. Copyright 2009 American Chemical Society.

Trimethylgermane C3H10Ge C3v CH3 GeH H 3C

CH3

386

5 Molecules with Three Carbon Atoms

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Dependent parameter. c Positive tilt indicates a decrease of the unique Ge−C−H bond angle and an increase of the pair of symmetryrelated Ge−C−H bond angles, i.e. away from the Ge−H bond. b

The GED experiment was carried out at Tnozzle = 293 K. Overall C3v symmetry and local C3v symmetry of each of the methyl groups were assumed. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/6-31G* computation. Roldán ML, Brandán SA, Masters SL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2009) Combined experimental studies and theoretical calculations to yield the complete molecular structure and vibrational spectra of (CH3)3GeH. J Phys Chem A 113 (17):5195-5204

477 CAS RN: 634591-14-3 MGD RN: 533779 MW augmented by ab initio calculations

2-Propanol – water (1/1) Isopropanol – water (1/1) C3H10O2 C1 OH

O

Distances O(5)…O(3) H(4)…O(3)

r0 [Å] a 2.969(3) 1.908 b

Dihedral angles O(5)…O(3)–C(2)–C(1) H(6)–O(5)…O(3)–C(2)

τ0 [deg] a

H H3C

H

CH3

184.0(2) -138(8)

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectra of the binary complex of isopropanol with water were recorded in a supersonic jet by Balle-Flygare type and chirped-pulse FTMW spectrometers in the frequency region between 6 and 18.5 GHz. Two distinct forms were observed. In the inner form the water subunit is oriented along the symmetry plane of the isopropanol subunit, whereas in the outer form the water subunit is positioned outside the isopropanol symmetry plane. The partial r0 structure of the outer form was determined from the ground-state rotational constants of five isotopic species (main, 18O, two D and D2); the remaining structural parameters were constrained to the MP2/6311++G(d,p) values. Evangelisti L, Gou Q, Feng G, Caminati W, Mead GJ, Finneran IA, Carroll PB, Blake GA (2017) Conformational equilibrium and internal dynamics in the iso-propanol-water dimer. Phys Chem Chem Phys 19(1):568-573

478 CAS RN: 288-85-7 MGD RN: 396050 MW augmented by

1,3-Disilacylopentane C3H10Si2 C2

5 Molecules with Three Carbon Atoms

387

QC calculations

Bonds Si–C(1) Si–C(2) C(2)–C(2ꞌ) Si–H(1) Si–H(2) C(1)–H C(2)–H(1) C(2)–H(2)

r0 [Å] a 1.8856(1) 1.8884(4) 1.5515(4) 1.4880(1) 1.4860(1) 1.0938(1) 1.0977(1) 1.0946(1)

rs [Å] a 1.886(15) 1.8847(66) 1.5481(4)

Bond angles Si–C(1)–Si C(1)–Si–C(2) Si–C(2)–C(2ꞌ) C(1)–Si–H(1) C(1)–Si–H(2) C(2)–Si–H(1) C(2)–Si–H(2) H–Si–H H–C(1)–Si H–C(1)–H H(1)–C(2)–Si H(2)–C(2)–Si H(1)–C(2)–C(2ꞌ) H(2)–C(2)–C(2ꞌ) H–C(2)–H

θ0 [deg] a

θs [deg] a

Dihedral angles C(2)–Si–C(1)–Si Si–C(2)–C(2')–Si

τ0 [deg] a

τs [deg] a

103.87(6) 102.20(6) 106.37(6) 110.343(1) 113.053(1) 109.451(1) 113.143(1) 108.519(1) 111.46(2) 107.19(2) 108.818(4) 113.037(4) 110.016(4) 111.935(4) 106.645(4)

11.46(3) 45.60(3)

H2Si

SiH2

103.84(20) 106.51(37)

13.8(17) 45.25(86)

Copyright 2013 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit.

The twist conformer, characterized by the nonplanar Si–C–C–Si moiety, was predicted by MP2 and B3LYP calculations with various basis sets (up to aug-cc-pVTZ) to be the most or only one stable form of the title molecule. The rotational spectrum was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18 GHz. Only the twisted conformer was observed. The r0 structure was determined by adjusting the MP2(full)/6-311+G(d,p) structure to the determined groundstate rotational constants of five isotopic species (main, two 13C, 29Si and 30Si). The rs structure was obtained for the heavy-atom skeleton. Guirgis GA, Klaassen JJ, Pate BH, Seifert NA, Darkhalil ID, Deodhar BS, Wyatt JK, Dukes HW, Kruger M, Durig JR (2013) Microwave, infrared, and Raman spectra, structural parameters, vibrational assignments and theoretical calculations of 1,3-disilacyclopentane. J Mol Struct 1049:400-408

479 CAS RN: 18365-32-7 MGD RN: 514869 GED augmented by

1,1,1-Trimethyldisilane C3H12Si2 C3v

388

5 Molecules with Three Carbon Atoms

ab initio computations

Bonds Si–Si Si–C Si–H C–H

rh1 [Å] a 2.335(2) 1.881(1) 1.504(4) 1.083(2)

Bond angles Si–Si–H Si–Si–C Si–C–H c

θh1 [deg] a

Dihedral angle H(1)–Si–Si–C(3)

τh1 [deg]

111.3(5) b 109.5(2) 110.8(3)

-60.0 d

Reproduced with permission of SNCSC [1].

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Restrained to the value from MP2/6-311+G* computation. c Average. d Adopted from computation as indicated above. b

The GED experiment was carried out at Tnozzle = 293 K. The molecule was determined to adopt the staggered conformation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from HF/6-31G* computation. Atkinson SJ, Robertson HE, Hölbling M, du Mont WW, Mitrofan C, Hassler K, Masters SL (2013) Do halogen and methyl substituents have electronic effects on the structures of simple disilanes? An experimental and theoretical study of the molecular structures of the series X3SiSiMe3 (X = H, F, Cl and Br). Struct Chem 24 (3):851-857

480 CAS RN: 6498-10-8 MGD RN: 482345 GED augmented by QC computations

Carbonic diisocyanate Diisocyanatomethanone C3N2O3 C2v (syn-syn) Cs (syn-anti) O

Bonds C(1)=O(1) C(1)–N(1) C(1)–N(2) N(1)=C(2) N(2)=C(3) C(2)=O(2) C(3)=O(3) Bonds

syn-syn 1.199(1) 1.401(1) 1.401(1) 1.220(1) 1.220(1) 1.191(1) 1.191(1)

rg [Å] a syn-anti 1.194(1) 1.417(1) 1.397(1) 1.259(1) 1.223(1) 1.154(1) 1.155(1)

re [Å] a,b syn-syn syn-anti

O

O C

C N

N

syn-syn

5 Molecules with Three Carbon Atoms

C(1)=O(1) C(1)–N(1) C(1)–N(2) N(1)=C(2) N(2)=C(3) C(2)=O(2) C(3)=O(3)

Bond angles N(1)–C(1)–N(2) C(1)–N(1)=C(2) C(1)–N(2)=C(3) N(1)=C(2)=O(2) N(2)=C(3)=O(3)

1.196(1) 1 1.392(1) 2 1.392(1) 2 1.213(1) 1 1.213(1) 1 1.150(1) 1 1.150(1) 1

389

1.191(1) 1 1.408(1) 2 1.389(1) 2 1.212(1) 1 1.215(1) 1 1.149(1) 1 1.150(1) 1 syn-anti

θe [Å] a,b

syn-syn 106.1(3) 125.9(6) 3 125.9(6) 3 171.8(6) 3 171.8(6) 3

syn-anti 110.3(6) 126.3(9) 4 129.1(9) 4 174.2(9) 4 173.8(9) 4

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from MP2/cc-pVTZ computation. b

Under the experimental conditions (Tnozzle =274 K), the title compound was found to exist as a mixture of two conformers, syn-syn (66(3) %) and syn-anti (34 %), with the antiperiplanar and/or synperiplanar O=C–N=C torsional angles. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2/cc-pVTZ quadratic and cubic force fields taking into account non-linear kinematic effects. Klapötke TM, Krumm B, Rest S, Scharf R, Schwabedissen J, Stammler HG, Mitzel NW (2016) Carbonyl diisocyanate CO(NCO)2: Synthesis and structures in solid state and gas phase. J Phys Chem A 120 (26):45344541

481 CAS RN: 69941-56-6 MGD RN: 400805 IR

Carbon monoxide trimer C 3O 3 C3h C

Distance Rcm b

r0 [Å] a 4.424

O

3

Reproduced with permission of AIP Publishing.

a b

Uncertainty was not given in the original paper. Distance between centers of mass.

The rotationally resolved IR spectrum of the carbon monoxide trimer was recorded in a pulsed supersonic jet by a quantum cascade laser spectrometer in the region at about 2144 cm-1. The partial r0 structure was determined under the assumption that the bond length in the monomer subunits was not changed upon complexation. Rezaei M, Sheybani-Deloui S, Moazzen-Ahmadi N, Michaelian KH, McKellar ARW (2013) Spectroscopic evidence for a planar cyclic CO trimer. J Chem Phys 138(7):071102/1-071102/3

390

5 Molecules with Three Carbon Atoms

[http://dx.doi.org/10.1063/1.4793220]

482 CAS RN: 76962-07-7 MGD RN: 134584 MW

Carbonyl sulfide trimer C3O3S3 C1

trimer 1 rs [Å] a 1.555(3) 1.571(16) 1.561(6) 1.168(4) 1.143(16) 1.158(5)

Bonds S(1)=C(1) S(2)=C(2) S(3)=C(3) C(1)=O(1) C(2)=O(2) C(3)=O(3)

O

trimer 3 rs [Å] a 1.574(21) 1.536(6) 1.553(5)

S

3

trimer 1

θs [deg] a

Bond angles S(1)=C(1)=O(1) S(2)=C(2)=O(2) S(3)=C(3)=O(3)

C

178.8(2) 179.3(5) 178.7(3)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

trimer 3

The rotational spectra of all singly substituted 13C, 18O, and 34S isotopic species (in natural abundance) were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the region between 2 and 8 GHz. Two conformational forms, a barrel-type trimer with two antiparallel monomer subunits (trimer 1) and a barrel-type trimer with all monomer subunits aligned parallelly (trimer 3), were detected; nine and seven isotopic species were studied for each conformer, respectively. Evangelisti L, Perez C, Seifert NA, Pate BH, Dehghany M, Moazzen-Ahmadi N, McKellar ARW (2015) Theory vs. experiment for molecular clusters: Spectra of OCS trimers and tetramers. J Chem Phys 142(10):104309/1104309/11 [http://dx.doi.org/10.1063/1.4914323]

483

CAS RN: 2095846-46-9

Carbon dioxide – carbon monoxide (2/1) C 3O 5 C2

MGD RN: 552769 IR

O a

Distances R1 b R2 c

r0 [Å] 3.552(2) 3.455(2)

Angle

θ0 [deg] a

ϕd

57.5(2)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

C

O

2

C

O

5 Molecules with Three Carbon Atoms

391

b

Distance between the center-of-mass of CO and the center-of-mass of the CO2 dimer. Center-of-mass separation of the two CO2 monomers in the CO2 dimer subunit. d Angle between the line connecting the C atoms of two CO2 monomer subunits and the OCO axis. c

The rotationally resolved IR spectra of the main and 12C16O-(12C18O2)2 isotopic species were recorded in a pulsed supersonic jet by a quantum cascade laser spectrometer in the carbon monoxide stretching region at 2150 cm-1. The partial r0 structure of the trimer with C2 symmetry axis along the CO subunit was determined from the ground-state rotational constants of both isotopic species under the assumption that the structures of CO and CO2 monomers were not changed upon complexation. Barclay AJ, McKellar ARW, Moazzen-Ahmadi N (2017) Infrared observation of a new mixed trimer, CO – (CO2)2. Chem Phys Lett 677:127-130

484 CAS RN: 213820-70-3 MGD RN: 140923 IR supported by ab initio calculations

Carbon dioxide – carbonyl sulfide (2/1) C 3O 5S C1 O

Distances C(2)...X(1) b C(3)...X(1)

r0 [Å] a 3.805(18) 4.207(15)

Angles C(2)...X(1)...C(3) O(9)–C(3)...X(1) O(6)–C(2)…C(3) S(5)...X(1)...C(2)

θ0 [deg] a

Dihedral angles O(9)–C(3)…X(1)…C(2) O(6)–C(2)…C(3)...X(1) S(5)...X(1)...C(2)…C(3)

τ0 [deg] a

C

O

2

O

C

S

51.01(23) 44.0(25) 63.0 c 138.5(14)

76.4 c -143.3 c 105.2(32)

Reprinted with permission. Copyright 2010 American Chemical Society

a b

Parenthesized uncertainties in units of the last significant digit. X(1) is the center-of-mass of the OCS subunit.

The rotationally resolved IR spectrum of the ternary complex of carbon dioxide with carbonyl sulfide was recorded in a supersonic jet by a tunable diode laser spectrometer at about 2058 cm-1. The relatively strong band at 2050 cm-1 was assigned to the most stable species with a barrel-shaped form, which was previously studied by MW spectroscopy, whereas the weaker band at 2050 cm-1 was assigned to a high-energy species predicted by ab initio. The isotopic species with 18OCS, C18O2 and 13CO2 were investigated in enriched samples. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species. Norooz Oliaee J, Mivehvar F, Dehghany M, Moazzen-Ahmadi N (2010) Infrared spectroscopic investigation of two isomers of the weakly bound complex OCS-(CO2)2. J Phys Chem A 114(49):12834-12838

392

5 Molecules with Three Carbon Atoms

485 CAS RN: 1890221-42-7 MGD RN: 487330 MW supported by ab initio calculations

Bonds Pd=C(1) C(1)=C(2) C(2)=C(3)

1,2-Propadienylidenepalladium C3Pd C∞v (see comment) Pd

C

C

C

r0 [Å]a 1.79898(4) 1.3009 b 1.2789 b

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainty in unit of the last significant digit. Fixed to the value calculated at the level CCSD(T)_ae/aug-cc-pwCV5Z-PP(for Pd) and corrected for r0 ‒ re difference assumed to that for PtC3. b

The rotational spectrum of the title compound (1Σ electronic ground state) was recorded in a supersonic jet by a broadband MW spectrometer in the frequency range between 6.5 and 18.5 GHz. The transient species was created by a gas phase reaction of laser-ablated Pd with a hydrocarbon precursor. The molecule was found to be linear or quasilinear. The r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 105Pd, 108 Pd, 110Pd, 13C3, 106Pd/13C3 and 108Pd/13C3). Bittner DM, Zaleski DP, Tew DP, Walker NR, Legon AC (2016) Highly unsaturated platinum and palladium carbenes PtC3 and PdC3 isolated and characterized in the gas phase. Angew Chem 128(11):3832-3835; Angew Chem Int Ed Engl 55(11):3768-3771

486 CAS RN: 1964503-45-4 MGD RN: 487120 MW supported by ab initio calculations

Bonds Pt=C(1) C(1)=C(2) C(2)=C(3)

1,2-Propadienylideneplatinum C3Pt C∞v (see comment) Pt

C

C

C

r0 [Å]a 1.7315(14) 1.2993(19) 1.2759(11)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound (1Σ electronic ground state) was recorded in a supersonic jet by a broadband MW spectrometer in the frequency range between 6.5 and 18.5 GHz. The transient species was created by a gas phase reaction of laser-ablated Pt with a hydrocarbon precursor. The molecule was found to be linear or quasilinear. The r0 structure was determined from the ground-state rotational constants of 26 isotopic species (main, 194Pt, 196 Pt, 198Pt, three 13C, three 13C2, 13C3, 194Pt/13C3, three 194Pt/13C, three 194Pt/13C2, 196Pt/13C3, three 196Pt/13C, three 196 Pt/13C2, 198Pt/13C3).

5 Molecules with Three Carbon Atoms

393

Bittner DM, Zaleski DP, Tew DP, Walker NR, Legon AC (2016) Highly unsaturated platinum and palladium carbenes PtC3 and PdC3 isolated and characterized in the gas phase. Angew Chem 128(11):3832-3835; Angew Chem Int Ed Engl 55(11):3768-3771

487 CAS RN: MGD RN: 216461 IR

Carbon disulfide trimer C3S6 D3 S

a

Distance C…C

r0 [Å] 3.811

Angle

θ0 [deg] a

θb

C

S

3

61.8

Reproduced with permission from the PCCP Owner Societies.

a b

Uncertainty was not given in the original paper. Angle between a monomer axis and the C…C…C plane.

The rotationally resolved IR spectrum of the carbon disulfide trimer was recorded in a supersonic jet by a tunable diode laser spectrometer in the region of the CS2 ν3 fundamental band at about 1535 cm-1. A perpendicular band and a parallel band were analyzed. The partial r0 structure was determined from the groundstate rotational constants of the main isotopic species under the assumption that the structural parameters of the monomer subunit were not changed upon complexation. Rezaei M, Norooz Oliaee J, Moazzen-Ahmadi N, McKellar ARW (2011) Infrared spectrum of the CS2 trimer: observation of a structure with D3 symmetry. Phys Chem Chem Phys 13(27):12635-12639

394

5 Molecules with Three Carbon Atoms

References: 383 384 385 386 387

388 389 390

391 392 393 394 395 396 397 398 399 400 401

402

Breier AA, Büchling T, Schnierer R, Lutter V, Fuchs GW, Yamada KMT, Mookerjea B, Stutzki J, Giesen TF (2016) Lowest bending mode of 13C-substituted C3 and an experimentally derived structure. J Chem Phys 145(23):234302/1-234302/10 Berger RJF, Mitzel NW (2010) Reinvestigation of the gas-phase structure of tris(trifluoromethyl)arsine. J Mol Struct 978 (1-3):205-208 Ramos LA, Ulic SE, Romano RM, Tong SR, Ge MF, Vishnevskiy YV, Berger RJ, Mitzel NW, Beckers H, Willner H, Della Védova CO (2011) Chlorodifluoroacetyl cyanide, ClF2CC(O)CN: synthesis, structure, and spectroscopic characterization. Inorg Chem 50 (19):9650-9659 Ramos LA, Ulic SE, Romano RM, Vishnevskiy YV, Mitzel NW, Beckers H, Willner H, Tong SR, Ge MF, Della Védova CO (2013) Chlorodifluoroacetyl isothiocyanate, ClF2CC(O)NCS: Preparation and structural and spectroscopic studies. J Phys Chem A 117 (27):5597-5606 Ramos LA, Ulic SE, Romano RM, Vishnevskiy YV, Berger RJF, Mitzel NW, Beckers H, Willner H, Tong SR, Ge MF, Della Védova CO (2012) Chlorodifluoroacetyl isocyanate, ClF2CC(O)NCO: Preparation and structural and spectroscopic studies. J Phys Chem A 116 (47):11586-11595 Grubbs GS, Powoski RA, Jojola D, Cooke SA (2010) Some geometric and electronic structural effects of perfluorinating propionyl chloride. J Phys Chem A 114(30):8009-8015 Wann DA, Zakharov AV, Reilly AM, McCaffrey PD, Rankin DWH (2009) Experimental equilibrium structures: Application of molecular dynamics simulations to vibrational corrections for gas electron diffraction. J Phys Chem A 113 (34):9511-9520 Berrueta Martínez Y, Reuter CG, Vishnevskiy YV, Bava YB, Lorena Picone A, Romano RM, Stammler HG, Neumann B, Mitzel NW, Della Védova CO (2016) Structural analysis of perfluoropropanoyl fluoride in the gas, liquid, and solid phases. J Phys Chem A 120 (15):24202430 Dewberry CT, Grubbs GS, Cooke SA (2009) A molecule with small rotational constants containing an atom with a large nuclear quadrupole moment: The microwave spectrum of trans-1-iodoperfluoropropane. J Mol Spectrosc 257(1):66-73 Thorwirth S, Lutter V, Javed AJ, Gauss J, Giesen TF (2016) Gas-phase spectroscopic detection and structural elucidation of carbon-rich group 14 binary clusters: Linear GeC3Ge. J Phys Chem A 120(2):254-259 Dorris RE, Trendell WC, Peebles RA, Peebles SA (2016) Rotational spectrum, structure, and interaction energy of the trifluoroethylene⋅⋅⋅carbon dioxide complex. J Phys Chem A 120(40):7865-7872 Shahi A, Arunan E (2015) Microwave spectrum of hexafluoroisopropanol and torsional behavior of molecules with a CF3-C-CF3 group. J Phys Chem A 119(22):5650-5657 Spezzano S, Tamassia F, Thorwirth S, Thaddeus P, Gottlieb CA, McCarthy MC (2012) A high-resolution isotopic study of the rotational spectrum of c-C3H2. Astrophys J Suppl Series 200(1):1/1-1/11 Leung HO, Marshall MD, Wronkovich MA (2017) The microwave spectrum and molecular structure of Ar-2,3,3,3-tetrafluoropropene. J Mol Spectrosc 337(1):80-85 Pérez C, Caballero-Mancebo E, Lesarri A, Cocinero EJ, Alkorta I, Suenram RD, Grabow JU, Pate BH (2016) The conformational map of volatile anesthetics: enflurane revisited. Chem Eur J 22(28):9804-9811 Lesarri A, Vega-Toribio A, Suenram RD, Brugh DJ, Nori-Shargh D, Boggs JE, Grabow JU (2011) Structural evidence of anomeric effects in the anesthetic isoflurane. Phys Chem Chem Phys 13(14):6610-6618 Gil DM, Tuttolomondo ME, Blomeyer S, Reuter CG, Mitzel NW, Ben Altabef A (2016) Gasphase structure of 2,2,2-trichloroethyl chloroformate studied by electron diffraction and quantum-chemical calculations. Phys Chem Chem Phys 18 (1):393-402 Anderton AM, Peebles RA, Peebles SA (2016) Rotational spectrum and structure of the 1,1difluoroethylene⋅⋅⋅carbon dioxide complex. J Phys Chem A 120(2):247-253 (a) Marshall MD, Leung HO, Scheetz BQ, Thaler JE, Muenter JS (2011) A chirped pulse Fourier transform microwave study of the refrigerant alternative 2,3,3,3-tetrafluoropropene. J Mol Spectrosc 266(1):37-42 (b) Leung HO, Marshall MD, Wronkovich MA (2017) The microwave spectrum and molecular structure of Ar-2,3,3,3-tetrafluoropropene. J Mol Spectrosc 337(1):80-85 See 394.

5 References

395

403

Obenchain DA, Bills BJ, Christenholz CL, Elmuti LF, Peebles RA, Peebles SA, Neill JL, Steber AL (2011) C-H⋅⋅⋅π interactions in the CHBrF2⋅⋅⋅HCCH weakly bound dimer. J Phys Chem A 115(44):12228-12234 (a) Sexton JM, Elliott AA, Steber AL, Peebles SA, Peebles RA, Neill JL, Muckle MT, Pate BH (2010) Characterization of C-H⋅⋅⋅π interactions in the structure of the CHClF2-HCCH weakly bound complex. Phys Chem Chem Phys 12(42):14263-14270 (b) See 403. Bimler J, Broadbent S, Utzat KA, Bohn RK, Restrepo A, Michels HH, True NS (2012) Microwave spectrum, molecular structure, and quadrupole coupling of vinyl chloroformate. J Mol Struct 1023:87-89 Christenholz CL, Dorris RE, Peebles RA, Peebles SA (2014) Characterization of two isomers of the vinyl fluoride⋅⋅⋅carbon dioxide dimer by rotational spectroscopy. J Phys Chem A 118(38):8765-8772 Evangelisti L, Favero LB, Maris A, Melandri S, Vega-Toribio A, Lesarri A, Caminati W (2010) Rotational spectrum of trifluoroacetone. J Mol Spectrosc 259(2):65-69 (a) Kuze N, Ishikawa A, Kono M, Kobayashi T, Fuchisawa N, Tsuji T, Takeuchi H (2015) Molecular structure and internal rotation of CF3 group of methyl trifluoroacetate: Gas electron diffraction, microwave spectroscopy, and quantum chemical calculation studies. J Phys Chem A 119 (9):1774-1786 (b) Defonsi Lestard ME, Tuttolomondo ME, Varetti EL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2009) Gas-phase structure and new vibrational study of methyl trifluoroacetate (CF3C(O)OCH3). J Raman Spectrosc 40 (12):2053-2062 Evangelisti L, Grabowiecki A, van Wijngaarden J (2011) Chirped pulse Fourier transform microwave study of 2,2,2-trifluoroethyl formate. J Phys Chem A 115(30):8488-8492 Krasnicki A, Kisiel Z, Drouin BJ, Pearson JC (2011) Terahertz spectroscopy of isotopic acrylonitrile. J Mol Struct 1006(1-3):20-27 Bellili A, Linguerri R, Hochlaf M, Puzzarini C (2015) Accurate structural and spectroscopic characterization of prebiotic molecules: The neutral and cationic acetyl cyanide and their related species. J Chem Phys 143(18):184314/1-184314/12 Uchida Y, Toyoda M, Kuze N, Sakaizumi T (2009) Microwave spectra, molecular structure and theoretical calculation of two isotopic species of acetyl isocyanate CD3C(O)NCO and 13 CH3C(O)NCO. J Mol Spectrosc 256(1):163-168 Klapötke TM, Krumm B, Moll R, Penger A, Sproll SM, Berger RJF, Hayes SA, Mitzel NW (2013) Structures of energetic acetylene derivatives HC≡CCH2ONO2, (NO2)3CCH2C≡ CCH2C(NO2)3 and trinitroethane, (NO2)3CCH3. Z Naturforsch, B 68 (5-6):719-731 Mani D, Arunan E (2013) Microwave spectroscopic and atoms in molecules. Theoretical investigations on the Ar⋅⋅⋅propargyl alcohol complex: Ar⋅⋅⋅H-O, Ar⋅⋅⋅π, and Ar⋅⋅⋅C interactions. ChemPhysChem 14(4):754-763 Elmuti LF, Peebles RA, Peebles SA, Steber AL, Neill JL, Pate BH (2011) Observation of a double C-H⋅⋅⋅π interaction in the CH2ClF⋅⋅⋅HCCH weakly bound complex. Phys Chem Chem Phys 13(31):14043-14049 Gou Q, Feng G, Evangelisti L, Vallejo-López M, Spada L, Lesarri A, Cocinero EJ, Caminati W (2014) How water interacts with halogenated anesthetics: The rotational spectrum of isoflurane–water. Chem Eur J 20:1980-1984 Stephens SL, Mizukami W, Tew DP, Walker NR, Legon AC (2012) The halogen bond between ethene and a simple perfluoroiodoalkane: C2H4⋅⋅⋅ICF3 identified by broadband rotational spectroscopy. J Mol Spectrosc 280:47-53 Gou Q, Feng G, Evangelisti L, Caminati W (2017) Rotational spectrum of the tetrafluoromethane-ethylene oxide. J Mol Spectrosc 335(5):84-87 Shahi A, Arunan E (2015) Microwave spectroscopic and theoretical investigations of the strongly hydrogen bonded hexafluoroisopropanol⋅⋅⋅water complex. Phys Chem Chem Phys 17(38):24774-24782 Durig JR, Zhou SX, Zhou CX, Durig NE (2010) Structural parameters, vibrational spectra and centrifugal distortion constants of F(CN)C=NX (X = H, F, Cl, Br) and CH3(Y)C=NH (Y = H, CN). J Mol Struct 967(1-3):1-14 See 420. Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and seven-membered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746 See 422.

404

405 406 407 408

409 410 411 412 413 414 415 416 417 418 419 420 421 422 423

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5 Molecules with Three Carbon Atoms

424 425 426 427 428 429 430 431 432 433

434 435 436 437 438 439 440 441

442

443

444 445

446 447

Puzzarini C, Penocchio E, Biczysko M, Barone V (2014) Molecular structure and spectroscopic signatures of acrolein: theory meets experiment. J Phys Chem A 118(33):66486656 Kawashima Y, Sato A, Orita Y, Hirota E (2012) Intermolecular interaction between CO or CO2 and ethylene oxide or ethylene sulfide in a complex, investigated by Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 116(4):1224-1236 Calabrese C, Vigorito A, Feng G, Favero LB, Maris A, Melandri S, Geppert WD, Caminati W (2014) Laboratory rotational spectrum of acrylic acid and its isotopologues in the 6-18.5 GHz and 52-74.4 GHz frequency ranges. J Mol Spectrosc 295:37-43 See 425. See 425. Bauder A (2013) Microwave spectrum of formic acetic anhydride. Mol Phys 111(14-15):19992002 See 425. Christenholz CL, Obenchain DA, Peebles SA, Peebles RA (2012) Reduced bandwidth chirpedpulse microwave spectroscopy for analysis of weakly bound dimers: Rotational spectrum and structural analysis of CH2ClF⋅⋅⋅FHC=CH2. J Mol Spectrosc 280:61-67 Grubbs GS, Powoski RA, Jojola D, Cooke SA (2010) Some geometric and electronic structural effects of perfluorinating propionyl chloride. J Phys Chem A 114(30):8009-8015 Strand TG, Gundersen S, Priebe H, Samdal S, Seip R (2009) Molecular structures, conformations, force fields and large amplitude motion of cis-3-chloro-2-propen-1-ol as studied by quantum chemical calculations and gas electron diffraction augmented with quantum chemical calculations on 2-propen-1-ol. J Mol Struct 921 (1-3):72-79 Lesarri A, Grabow JU, Caminati W (2009) Conformation of chiral molecules: The rotational spectrum of 2-chloropropionic acid. Chem Phys Lett 468(1-3) 18-22 Aarset K, Boldermo KG, Hagen K (2010) Molecular structure and conformational composition of methyl chloroacetate: An electron-diffraction and ab initio molecular orbital investigation. J Mol Struct 978 (1-3):104-107 Evangelisti L, Feng G, Gou Q, Caminati W (2014) The rotational spectrum of formic acid⋅⋅⋅fluoroacetic acid. J Mol Spectrosc 299:1-5 Christenholz CL, Obenchain DA, Peebles RA, Peebles SA (2014) Rotational spectroscopic studies of C-H⋅⋅⋅F interactions in the vinyl fluoride⋅⋅⋅difluoromethane complex. J Phys Chem A 118(9):1610-1616 Favero LB, Evangelisti L, Maris A, Vega-Toribio A, Lesarri A, Caminati W (2011) How trifluoroacetone interacts with water. J Phys Chem A 115(34):9493-9497 Calabrese C, Vigorito A, Maris A, Mariotti S, Fathi P, Geppert WD, Melandri S (2015) Millimeter wave spectrum of the weakly bound complex CH2=CHCN⋅⋅⋅H2O: structure, dynamics, and implications for astronomical search. J Phys Chem A 119(48):11674-11682 Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612 (a) See 440. (b) Møllendal H, Demaison J, Petiprez D, Wlodarczak G, Guillemin J-C (2005) Structural and conformational properties of 1,2-propadienylphosphine (allenylphosphine) studied by microwave spectroscopy and quantum chemical calculations. J Phys Chem A 109:115-121 Demaison J, Craig NC, Gurusinghe R, Tubergen MJ, Rudolph HD, Coudert LH, Szalay PG, Császár AG (2017) Fourier transform microwave spectrum of propene-3-d1 (CH2=CHCH2D), quadrupole coupling constants of deuterium, and a semiexperimental equilibrium structure of propene. J Phys Chem A 121(16):3155-3166 Zaleski DP, Mullaney JC, Bittner DM, Tew DP, Walker NR, Legon AC(2015) Interaction of a pseudo-π C-C bond with cuprous and argentous chlorides: Cyclopropane⋅⋅⋅CuCl and cyclopropane⋅⋅⋅AgCl investigated by rotational spectroscopy and ab initio calculations. J Chem Phys 143(16):164314/1-164314/13 See 443. Kuze N, Watado T, Takahashi Y, Sakaizumi T, Ohashi O, Kiuchi M, Iijima K (2015) Molecular structure and internal rotation of CH2Cl group of chloropropanone oxime: Gas electron diffraction, microwave spectroscopy, and quantum chemical calculation studies. Struct Chem 26 (5-6):1241-1257 See 445. Białkowska-Jaworska E, Pszczółkowski L, Kisiel Z (2015) Comprehensive analysis of the rotational spectrum of 2,2-dichloropropane. J Mol Spectrosc 308:20-27

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449 450 451 452

453 454 455 456 457 458 459 460 461

462 463 464

465 466

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5 Molecules with Three Carbon Atoms

467

468 469 470 471

472 473 474 475 476 477 478

479 480 481 482 483 484 485 486 487

Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 119(10):2132-2141 Tatamitani Y, Kawashima Y, Osamura Y, Hirota E (2015) Intermolecular interaction in the formaldehyde-dimethyl ether and formaldehyde-dimethyl sulfide complexes investigated by Fourier transform microwave spectroscopy and ab initio calculations. J Phys Chem A 119(10):2132-2141 Evangelisti L, Spada L, Li W, Ciurlini A, Grabow JU, Caminati W (2016) Shape of the adduct formic acid-dimethyl ether: A rotational study. J Phys Chem A 120(18):2863-2867 Conrad AR, Teumelsan NH, Wang PE, Tubergen MJ (2010) A spectroscopic and computational investigation of the conformational structural changes induced by hydrogen bonding networks in the glycidol-water complex. J Phys Chem A 114(1):336-342 van Wijngaarden J, Chen Z, van Dijk CW, Sorensen JL (2011) Pure rotational spectrum and ring inversion tunneling of silacyclobutane. J Phys Chem A 115(31):8650-8655 Atkinson SJ, Robertson HE, Hölbling M, du Mont WW, Mitrofan C, Hassler K, Masters SL (2013) Do halogen and methyl substituents have electronic effects on the structures of simple disilanes? An experimental and theoretical study of the molecular structures of the series X3SiSiMe3 (X = H, F, Cl and Br). Struct Chem 24 (3):851-857 See 471. See 471. Durig JR, Klaassen JJ, Darkhalil ID, Herrebout WA, Dom JJJ, van der Veken BJ (2012) Conformational and structural studies of isopropylamine from temperature dependent Raman spectra of xenon solutions and ab initio calculations. J Mol Struct 1009:30-41 Giuliano BM, Melandri S, Maris A, Favero LB, Caminati W (2009) Adducts of NH3 with the conformers of glycidol: A rotational spectroscopy study. Angew Chem 121(6):1122-1125; Angew Chem Int Ed 48(6):1102-1105 Roldán ML, Brandán SA, Masters SL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2009) Combined experimental studies and theoretical calculations to yield the complete molecular structure and vibrational spectra of (CH3)3GeH. J Phys Chem A 113 (17):5195-5204 Evangelisti L, Gou Q, Feng G, Caminati W, Mead GJ, Finneran IA, Carroll PB, Blake GA (2017) Conformational equilibrium and internal dynamics in the iso-propanol-water dimer. Phys Chem Chem Phys 19(1):568-573 Guirgis GA, Klaassen JJ, Pate BH, Seifert NA, Darkhalil ID, Deodhar BS, Wyatt JK, Dukes HW, Kruger M, Durig JR (2013) Microwave, infrared, and Raman spectra, structural parameters, vibrational assignments and theoretical calculations of 1,3-disilacyclopentane. J Mol Struct 1049:400-408 See 471. Klapötke TM, Krumm B, Rest S, Scharf R, Schwabedissen J, Stammler HG, Mitzel NW (2016) Carbonyl diisocyanate CO(NCO)2: Synthesis and structures in solid state and gas phase. J Phys Chem A 120 (26):4534-4541 Rezaei M, Sheybani-Deloui S, Moazzen-Ahmadi N, Michaelian KH, McKellar ARW (2013) Spectroscopic evidence for a planar cyclic CO trimer. J Chem Phys 138(7):071102/1-071102/3 Evangelisti L, Perez C, Seifert NA, Pate BH, Dehghany M, Moazzen-Ahmadi N, McKellar ARW (2015) Theory vs. experiment for molecular clusters: Spectra of OCS trimers and tetramers. J Chem Phys 142(10):104309/1-104309/11 Barclay AJ, McKellar ARW, Moazzen-Ahmadi N (2017) Infrared observation of a new mixed trimer, CO – (CO2)2. Chem Phys Lett 677:127-130 Norooz Oliaee J, Mivehvar F, Dehghany M, Moazzen-Ahmadi N (2010) Infrared spectroscopic investigation of two isomers of the weakly bound complex OCS-(CO2)2. J Phys Chem A 114(49):12834-12838 Bittner DM, Zaleski DP, Tew DP, Walker NR, Legon AC (2016) Highly unsaturated platinum and palladium carbenes PtC3 and PdC3 isolated and characterized in the gas phase. Angew Chem 128(11):3832-3835; Angew Chem Int Ed Engl 55(11):3768-3771 See 485. Rezaei M, Norooz Oliaee J, Moazzen-Ahmadi N, McKellar ARW (2011) Infrared spectrum of the CS2 trimer: observation of a structure with D3 symmetry. Phys Chem Chem Phys 13(27):12635-12639

Chapter 6. Molecules with Four Carbon Atoms

488 CAS RN: 3958-03-0 MGD RN: 383299 GED combined with MS and augmented by QC computations Bonds S–C(5) C(3)–C(4) C(4)=C(5) C(5)–Br C(4)–Br

rh1 [Å] a 1.721(4) 1.444(12) 1.358(6) 1.863(5) 1.872(5)

Bond angles C–S–C S–C(2)–Br C(3)–C(4)=C(5) C(2)=C(3)–Br

θh1 [deg] b

2,3,4,5-Tetrabromothiophene

Br

Br

C4Br4S C2v Br

Br

S

91.1 c 119.9(3) 111.9(4) 124.7(6)

Copyright 2012 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parenthesized uncertainties in units of the last significant digit are 3σ values. c Dependent parameter. The GED experiment was carried out at Teffusion cell = 347(3) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/aug-cc-pVTZ computation. Zhabanov YA, Vande Velde CML, Blockhuys F, Shlykov SA (2012) Molecular structures of tetrabromothiophene and -selenophene as determined by gas-phase electron diffraction and high-level quantum chemical calculations. J Mol Struct 1030:75-82 489 CAS RN: 606925-84-2 MGD RN: 383109 GED combined with MS and augmented by QC computations Bonds Se–C(5) C(3)–C(4) C(4)=C(5) C(5)–Br C(4)–Br

rh1 [Å] a 1.868(4) 1.449(3) 1.381(3) 1.872(4) 1.871(4)

© Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_6

2,3,4,5-Tetrabromoselenophene

Br

Br

C4Br4Se C2v Br

Se

Br

399

400

Bond angles C–Se–C Se–C(2)–Br C(3)–C(4)=C(5) C(2)=C(3)–Br

6 Molecules with Four Carbon Atoms

θh1 [deg] b 86.9 c 120.8(3) 113.9(3) 123.4(3)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parenthesized uncertainties in units of the last significant digit are 3σ values. c Dependent parameter. The GED experiment was carried out at Teffusion cell = 345(3) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from MP2_full/aug-cc-pVTZ computation. Zhabanov YA, Vande Velde CML, Blockhuys F, Shlykov SA (2012) Molecular structures of tetrabromothiophene and -selenophene as determined by gas-phase electron diffraction and high-level quantum chemical calculations. J Mol Struct 1030:75-82

490 CAS RN: 35449-89-9 MGD RN: 388166 GED augmented by QC computations

P,P-Bis(1,1,2,2,2-pentafluoroethyl)phosphinous chloride C4ClF10P close to Cs (I) C1 (II) F

Bonds P–Cl P–C(1') P–C(1) C(1')–C(2') C(1)–C(2) C–F d C–F(1) C–F(2) C–F(1') C–F(2') Bonds angles C–P–C Cl–P–C(1') Cl–P–C(1) P–C(1')–C(2') P–C(1)–C(2) Dihedral angles C(1)–P–C(1')–C(2') C(1')–P–C(1)–C(2)

rh1[Å] a,b II 2.018(3) c 1.914(3) 1.904(3) 1.544(3) 1.544(3) 1.333(1) e 1.347(2) 1.357(2) 1.354(2) 1.349(2)

I 2.018(3) c 1.907(3) 1.897(3) 1.544(3) 1.544(3) 1.333(1) e 1.346(2) 1.357(2) 1.347(2) 1.357(2)

I 98.2(4) 100.1(3) 101.7(3) 111.8(3) 114.6(3)

θh1 [deg] a,b

II 100.5(4) 99.3(3) 100.0(3) 112.5(3) 112.2(3)

τh1 [deg] a,b

I -169.1(10) -165.3(9)

II -102.6(9) 171.7(10)

rg[Å] a,b I II 2.015(4) c 2.015(4)c 1.904(3) 1.911(3) 1.894(3) 1.900(3) 1.528(3) 1.528(3) 1.528(3) 1.528(3) 1.332(1) e 1.332(1) e 1.346(2) 1.346(2) 1.357(2) 1.356(2) 1.346(2) 1.354(2) 1.356(2) 1.349(2)

θg [deg] a,b

I 98.6(4) 99.8(3) 101.4(3) 112.0(3) 114.8(3)

II 101.0(4) 99.0(3) 99.7(3) 112.7(3) 112.4(3)

τg [deg] a,b

I -169.0(10) -164.6(9)

II -102.4(9) 171.9(10)

Cl

F

F

F

P F

F F

F

F

F

6 Molecules with Four Carbon Atoms

401

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

I

II

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Many refined parameters (35 of 43 in total) were restrained to the values from MP2/TZVPP computation. c The P–Cl bond lengths were assumed to be equal in both conformers. d In the CF3 group. e Average value, assumed to be equal in both conformers. b

Four stable low-energy conformers, differing by the magnitude of the C–P–C–C torsional angles, with small relative energies (up to 2.8 kJ mol-1) and with many large-amplitude motions were predicted by MP2/TZVPP calculations. The GED experiment was carried out at room temperature. A model of two conformers, I and II, differing in the magnitude of the C–P–C–C torsional angle was found to be the most appropriate for description of the experimental data. The conformer I was found to be dominant (61(5)%). Local C3v symmetry was assumed for the C–CF3 groups. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3PW91/6-311G(2d) computations. Hayes SA, Berger RJF, Mitzel NW, Bader J, Hoge B (2011) Chlorobis(pentafluoroethyl)phosphane: Improved synthesis and molecular structure in the gas phase. Chem Eur J 17 (14):3968-3976

491 CAS RN: 33420-44-9 MGD RN: 360932 GED augmented by QC computations

(2Z,3Z)-2,3-Bis(chloroimino)butanedinitrile C4Cl2N4 C2h (anti-ZZ) N

Bonds C(3)–C(2) C(2)=N(3) N(3)–Cl C(2)–C(1) C(1)≡N(1)

ra [Å] a 1.509(15) 1.295(6) 1.706(5) 1.434(11) 1.165(5)

Bond angles C(3)–C(2)=N(3) C(2)=N(3)–Cl C(1)–C(2)–C(3) C(2)–C(1)≡N(1)

θα [deg] b

114.5(11) 115.0(4) 118.8(8) 178.2(15) c

Cl

C

N

N

C

Cl

N

402

6 Molecules with Four Carbon Atoms

Dihedral and other angles N(3)=C(2)−C(3)=N(4)

δ

e

τα [deg] b 180.0 d 15.3(35)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.001r. b Parenthesized uncertainties in units of the last significant digit are 2.5σ values. c Bent towards the Cl atom. d Assumed to be planar in the equilibrium configuration. e Root-mean-square angular amplitude of the N(3)=C(2)−C(3)=N(4) torsional angle. According to prediction of B3LYP/6-31G* computations, the planar anti conformer with C2h point-group symmetry, characterized by the antiperiplanar C–C–C–C torsional angle, is the lowest energy conformer of the title molecule with the cis orientation of the C(1,8)–C=N–Cl fragments (ZZ). The anti conformers of the EE and EZ isomers with the trans (E) or cis orientations of the C(1,8)–C=N–Cl moieties, as well as non-planar anti conformer of the ZZ isomer were predicted to be higher in energy by more than 17 kJ mol−1. Therefore, only the planar anti-ZZ conformer was considered in the GED analysis. The GED experiment was carried out at the nozzle temperature in the range of 362…364 K. Harmonic vibrational corrections to the experimental internuclear distances, ∆rα = ra − rα, were calculated using quadratic force constants from MP2/6-311G* computation. The most reliable results were obtained with a dynamic model describing the large-amplitude motion around the central C−C bond. Thomassen H, Gundersen S, Samdal S (2009) The molecular structures, conformations and force fields of bis(chloroimino)butanedinitrile as studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 928 (1-3):182-188

492 CAS RN: 1159100-58-9 MGD RN: 523227 GED augmented by QC computations

P,P-Bis(1,1,2,2,2-pentafluoroethyl)phosphinous acid C4HF10OP C1 (anti-anti) C1 (anti-gauche) F

Bonds P–C(2) P–C(3) P–O C(2)–C(4) C(3)–C(5) C(2)–F(6) C(2)–F(8) C(3)–F(7) C(3)–F(9) C(4)–F(10) C(4)–F(12) C(4)–F(14) C(5)–F(11) C(5)–F(13) C(5)–F(15) Angles

OH

F

a,b

re,MD [Å] anti-anti anti-gauche 1.888(3) 1 1.886(3) 1 1.900(3) 1 1.896(3) 1 2 1.582(3) 1.583(3) 2 2 1.530(3) 1.529(3) 2 2 1.526(3) 1.526(3) 2 3 1.342(1) 1.344(1) 3 1.347(1) 3 1.346(1) 3 3 1.337(1) 1.346(1) 3 3 1.349(1) 1.348(1) 3 3 1.326(1) 1.326(1) 3 3 1.325(1) 1.325(1) 3 3 1.323(1) 1.323(1) 3 3 1.324(1) 1.321(1) 3 3 1.327(1) 1.328(1) 3 3 1.322(1) 1.323(1) 3

θe,MD [deg] a

F

F

P F

F F

F

F

F

anti-anti

6 Molecules with Four Carbon Atoms

anti-anti 92.7(5) 112.9(3) 111.5(3)

C(2)–P–C(3) C(4)–C(2)–P C(5)–C(3)–P Dihedral angles C(4)–C(2)–P–C(3) C(5)–C(3)–P–C(2)

anti-anti 177(3) 173(3)

403

anti-gauche 97.0(5) 112.9(3) 119.6(3)

τe,MD [deg] a

anti-gauche 179(3) 71(3)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

anti-gauche

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from O3LYP/aug-cc-pVTZ computation.

b

The GED experiment was carried out at Tnozzle = 295.15 K. The title compound was found to exist as a mixture of two conformers, anti-anti (85(6)%) and anti-gauche, characterized by the antiperiplanar and synclinal C(5)– C(3)–P–C(2) dihedral angles, respectively. The C(4)–C(2)–P–C(3) dihedral angle is antiperiplanar in each of these conformers. Anharmonic vibrational corrections to the experimental internuclear distances, ∆re,MD = ra − re,MD, were derived from MD trajectories (at the BLYP level of theory in conjunction with the DZVP basis set). Zakharov AV, Vishnevskiy YV, Allefeld N, Bader J, Kurscheid B, Steinhauer S, Hoge B, Neumann B, Stammler HG, Berger RJF, Mitzel NW (2013) Functionalized bis(pentafluoroethyl)phosphanes: Improved syntheses and molecular structures in the gas phase. Eur J Inorg Chem (19):3392-3404

493 CAS RN: 887349-50-0 MGD RN: 516144 GED augmented by QC computations

Bonds P(1)–C(2) P(1)–C(3) C(2)–C(4) C(3)–C(5) C(2)–F(6) C(2)–F(8) C(3)–F(7) C(3)–F(9) C(4)–F(10) C(4)–F(12) C(4)–F(14) C(5)–F(11) C(5)–F(13) C(5)–F(15)

rg [Å] a 1.897(3) 1.896(3) 1.533(3) 1.535(3) 1.349(1) 1.348(1) 1.349(1) 1.348(1) 1.333(1) 1.337(1) 1.327(1) 1.332(1) 1.336(1) 1.327(1)

Bond angles C(2)–P(1)–C(3) C(4)–C(2)–P(1) C(5)–C(3)–P(1)

Bis(1,1,2,2,2-pentafluoroethyl)phosphine C4HF10P C1 (anti-anti) C1 (anti-gauche)

re,MD [Å] a,b 1.882(3) 1.886(3) 1.519(3) 1.518(3) 1.346(1) 1.343(1) 1.344(1) 1.343(1) 1.328(1) 1.330(1) 1.322(1) 1.326(1) 1.333(1) 1.323(1)

re [Å] a,c 1.876(3) 1.880(3) 1.516(3) 1.515(3) 1.344(1) 1.341(1) 1.343(1) 1.341(1) 1.325(1) 1.327(1) 1.318(1) 1.323(1) 1.330(1) 1.318(1)

θe,MD [deg] a

θe [deg] a

98.4(8) 112.6(2) 111.7(2)

98.6(6) 111.3(2) 110.4(2)

anti-anti

404

6 Molecules with Four Carbon Atoms

τe,MD [deg] a

Dihedral angles C(4)–C(2)–P(1)–C(3) C(5)–C(3)–P(1)–C(2)

166(3) 176(3)

τe [deg] a 133(2) 143(2)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Differences between the bond lengths of the same kind were fixed at the values from the O3LYP/aug-cc-pVTZ computation. Anharmonic vibrational corrections to the experimental internuclear distances, ∆re,MD = ra − re,MD, were derived from MD simulations at the BLYP/DZVP level of theory. c Differences between the bond lengths of the same kind were fixed at the values from the B3LYP/cc-pVTZ computation. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP/6-31++G** quadratic and cubic force fields taking into account non-linear kinematic effects. b

The GED experiment was carried out at Tnozzle = 295.15 K. The title compound was found to exist as a mixture of two conformers, anti-anti (94(6)%) and anti-gauche, characterized by the antiperiplanar and synclinal C(5)– C(3)–P(1)–C(2) torsional angles, respectively. The C(4)–C(2)–P(1)–C(3) chain is antiperiplanar in each of both comformers. Structural parameters are presented for the dominant conformer (anti-anti). Two sets of equilibrium structural parameters were obtained applying the different methods for calculations of vibrational corrections to the experimental internuclear distances (see footnotes b and c). The reason of discrepancies between these sets of corrections could not be explained. Zakharov AV, Vishnevskiy YV, Allefeld N, Bader J, Kurscheid B, Steinhauer S, Hoge B, Neumann B, Stammler HG, Berger RJF, Mitzel NW (2013) Functionalized bis(pentafluoroethyl)phosphanes: Improved syntheses and molecular structures in the gas phase. Eur J Inorg Chem (19):3392-3404

494 CAS RN: 149961-50-2 MGD RN: 134086 MW

2-Propynenitrile – carbon monoxide (1/1) Cyanoacetylene – carbon monoxide (1/1) C4HNO C∞ v H

Distances C(4)…H C(4)…D Rcm b

C

C

C

N

C

O

a

r0 [Å] 2.65315(27) 2.64962(27) 6.2031

Copyright 2012 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits.

The rotational spectra of the binary complex of cyanoacetylene with carbon monoxide were recorded in a pulsed supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 3.7 and 26.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of thirteen isotopic species (main, 18O, 15N, four 13C, D, 18O/D, three 13C/D and 15N/D). The hydrogen bond decreases by about 0.0035 Å upon deuteration. Kang L, Novick SE (2012) The microwave spectra of the weakly bound complex between carbon monoxide and cyanoacetylene, OC H–C≡C–C≡N. J Mol Spectrosc 276-277:10-13

6 Molecules with Four Carbon Atoms

495 CAS RN: 184590-43-0 MGD RN: 136239 MW supported by QC calculations

Distance Rcm b

r0 [Å] a 4.8311(3)

Angles

θ0 [deg] a

c

ϕ φd

405

2-Propynenitrile – carbon dioxide (1/1) Cyanoacetylene – carbon dioxide (1/1) C4HNO2 C2v H

C

C

C

N

O

C

O

10(1) 5.4(5)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Angle of torsional oscillation about the a axis, defined as the angle between this axis and the HCCCN axis. d Angle of torsional oscillation about an axis parallel to b one (bꞌ), defined as the angle between bꞌ and the O=C=O axis. b

The rotational spectrum of cyanoacetylene with carbon dioxide was recorded by two pulsed-jet Balle-Flygare type FTMW spectrometers in the frequency region between 1.4 and 25 GHz. The partial r0 structure was determined under the assumption that the structural parameters of monomer subunits were not changed upon complexation. The torsional oscillation model was suggested to describe the weakly bounding of the T-shaped complex. Kang L, Davis P, Dorell I, Li K, Oncer O, Wang L, Novick SE, Kukolich SG (2017) Rotational spectrum and structure of the T-shaped cyanoacetylene carbon dioxide complex, HCCCN⋅⋅⋅CO2. J Mol Spectrosc 342(6):62-72

496 CAS RN: 5330-98-3 MGD RN: 214511 GED supplemented by QC computations

2-Chloro-3-nitrothiophene C4H2ClNO2S Cs O N

Bonds N=O(1) N=O(2) C(4)=C(5) C(2)=C(3) C(3)–C(4) C(3)–N C(2)–Cl C(5)–S C(2)–S C(4)–H C(5)–H

O

a,b

re [Å] 1.225(3) 1 1.227(3) 1 1.362(3) 2 1.376(3) 2 1.403(3) 2 1.438(3) 2 1.700(2) 3 1.712(2) 3 1.715(2) 3 1.072 c 1.071 c

S

Cl

406

6 Molecules with Four Carbon Atoms

θe [deg] a

Bond angles C(2)–S–C(5) S–C(2)–C(3) S–C(5)–C(4) C(3)–C(4)=C(5) C(2)=C(3)–C(4) O=N=O C(3)–C(4)–H C(5)=C(4)–H S–C(5)–H S–C(2)–Cl C(3)–N=O(1) C(4)–C(3)–N

92.2(5) 110.8(6) 111.3(5) 113.0(7) 112.7(8) 124.6(6) 122.7(4) 124.6(4) 120.3(3) 118.6(5) 118.5(6) 121.8(7)

Copyright 2015 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2_full/cc-pVTZ computation. c Assumed. b

According to predictions of B3LYP and MP2_full calculations in conjunction with various Pople and Dunning basis sets, the structure of the title molecule is planar. The GED experiment was carried out at Tnozzle = 323 K. Rotation of the nitro group around the C–N bond was described by a large-amplitude motion model using twofold cosine PEF and taking into account relaxation effects. The GED data were found to be consistent with the barrier height in the range between 600 and 1400 cm-1. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from the MP2_full/cc-pVTZ harmonic and anharmonic force fields taking into account non-linear kinematic effects. Kovtun DM, Kochikov IV, Tarasov YI (2015) Internal rotation and equilibrium structure of 2-chloro-3nitrothiophene from gas electron diffraction and quantum chemistry. J Mol Struct 1100:311-317

497 CAS RN: 3172-52-9 MGD RN: 363633 GED augmented by QC computations

Bonds r1 b C(2)=C(3) S–C C−Cl C(3)–C(4) C−H Bond angles C−S−C S–C=C S–C–Cl C(2)=C(3)−H C(2)=C(3)–C(4)

2,5-Dichlorothiophene C4H2Cl2S C2v Cl

rh1 [Å] a 1.723(1) 1.369(4) 1.730(6) c 1.715(6) c 1.435(8) c 1.077(8) d

θh1 [deg] a 90.2(2) 113.1(4) 119.8(1) 121.6(9) d 111.8(3) c

S

Cl

6 Molecules with Four Carbon Atoms

407

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Mean value of the S–C and C–Cl bond lengths. c Dependent parameter. d Restrained to the value from MP2/6-311+G(3df,3pd) computation. b

The GED experiment was carried out at Tnozzle = 328 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from MP2/6-31G(d) computation. Schirlin JT, Wann DA, Bone SF, Robertson HE, Rankin DWH (2009) Additivity of ring geometry distortion effects in unsaturated five-membered heterocyclic rings. J Mol Struct 922 (1-3):103-108

498 CAS RN: 382-10-5 MGD RN: 157481 MW

3,3,3-Trifluoro-2-(trifluoromethyl)-1-propene 1,1-Bis(trifluoromethyl)ethylene C4H2F6 C1 CH2

Bonds C(1)–C(2) C(1)–C(3) C(1)=C(4)

rs [Å] a 1.465(2) 1.465(2) 1.339(4)

Bond angles C(2)–C(1)–C(3) C(2)–C(1)–C(4) C(3)–C(1)=C(4)

θs [deg] a

F

F

F

F

F

F

121.0(2) 116.1(12) 122.9(12)

Dihedral angle τs [deg] a C(2)–C(1)=C(4)…C(3) 180(0) Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rs structure of the carbon skeleton was determined from the previously published ground-state rotational constants. Shahi A, Arunan E (2015) Microwave spectrum of hexafluoroisopropanol and torsional behavior of molecules with a CF3–C–CF3 group. J Phys Chem A 119(22):5650-5657

499 CAS RN: 407-38-5 MGD RN: 356236 GED augmented by QC computations

2,2,2-Trifluoroacetic acid 2,2,2-trifluoroethyl ester 2,2,2-Trifluoroethyl trifluoroacetate C4H2F6O2 C1 (anti-gauche) Cs (anti-anti)

408

Bonds r1 C–C C(1ʹ)–O C=O C–H C(2)−F(3) C(2)−F(4) C(2)−F(5) C(2ʹ)−F(3ʹ) C(2ʹ)−F(4ʹ) C(2ʹ)−F(5ʹ) C(1)−O(7) C(2)−C(1) C(1ʹ)−C(2ʹ) Bond angles C–C(2)–F C–C(2ʹ)–F F–C(2ʹ)–F O–C=O C–C(1)–O C–O–C O–C–C H–C–H O(7)–C(1)=O(6) C(2)–C(1)–O(7) C(1)–O(7)–C(1ʹ) O(7)–C(1ʹ)–C(2ʹ) Dihedral angles C(1)–O(7)−C(1ʹ)–C(2ʹ) C(2)−C(1)−O(7)–C(1ʹ)

6 Molecules with Four Carbon Atoms

ra3,1 [Å] a anti-gauche anti-anti 1.3332(4) b 1.3332(4) b 1.5116(15) 1.5116(15) 1.423(4) 1.423(4) 1.212(3) 1.212(3) 1.089(5) c 1.089(5) c d 1.322(1) 1.322(1) d 1.334(1) d 1.333(1) d d 1.332(1) 1.337(1) d 1.338(1) d d 1.334(1) 1.334(1) d d 1.334(1) 1.341(5) d 1.336(5) d d 1.527(3) 1.527(3) d d 1.500(3) 1.496(3) d

O F

F O

F

F F

F

anti-gauche

θa3,1 [deg] a

anti-gauche 109.8(6) c 111.5(5) c 108.5(10) c 123.5(10) c 110.2(6) c 115.4(7) c 107.5(5) c 110.6(10) c 123.9(11) d 109.7(7) d 116.5(7) d 108.8(6) d

anti-gauche 102.5(11) 180.1(18)

anti-anti 109.8(6) c 111.5(5) c 108.5(10) c 123.5(10) c 110.2(6) c 115.4(7) c 107.5(5) c 110.6(10) c 123.2(10) d 110.7(6) d 114.4(7) d 106.3(5) d

anti-anti

τa3,1 [deg] a

anti-anti 180.0 e 180.0 e

Copyright 2008 with permission from Elsevier. a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value of the C−F and C−O bond lengths. Differences between these parameters were restrained to the values from MP2/6-311++G(d,p) computation. c Average value for two conformers. d Dependent parameter. Differences between related parameters were restrained to the values from computation at the level of theory as indicated above. e Fixed. b

According to predictions of MP2/6-311++G(d,p) computations, the title molecules exist as a mixture of the antianti and anti-gauche conformers differing in the magnitude of the C(1)–O(7)−C(1ʹ)–C(2ʹ) dihedral angle, the anti-anti conformer being lower in energy. The free energy difference was estimated to be 2.1 kJ mol−1. The GED experiment was carried out at room temperature (approximately 293 K). The ratio of the conformers was determined to be anti-gauche : anti-anti = 45(3) : 55(3). Vibrational corrections to the experimental internuclear distances, ∆r = ra − ra3,1, were calculated from the MP2/6-31G(d) quadratic and cubic force fields taking into account non-linear kinematic effects.

6 Molecules with Four Carbon Atoms

409

The analysis of the total potential energy in terms of a Fourier expansion showed that the steric interactions favour anti-anti conformer, while the hyper conjugative effects favour anti-gauche conformer. Defonsi Lestard ME, Tuttolomondo ME, Varetti EL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2009) Experimental and theoretical studies of the vibrations and structure of 2,2,2-trifluoroethyl trifluoroacetate, CF3CO2CH2CF3. J Mol Struct 917 (2-3):183-192

500 CAS RN: 243864-46-2 MGD RN: 142086 IR

Ethyne – carbonyl sulfide (1/2) Acetylene – carbonyl sulfide (1/2) C4H2O2S2 C2 (assumed) O

C

S

H

2

C

C

H

a

Distances X(4)…X(3) b X(4)…X(1) b

r0 [Å] 3.121(2) 1.8238(6)

Angles C(1)...X(1)...X(2) c C(1)...X(1)...X(4)...X(3) X(1)...X(4)...X(3)...C(2) d

θ0 [deg] a

89.37(54) -79.97(12) 87.5

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. X(3) is the center-of-mass of the HCCH subunit, X(1) and X(2) are the centers of mass of the single OCS subunits, X(4) is the center-of-mass of the OCS dimer. c Angle of 90° corresponds to a slip angle of zero between both OCS subunits. d A value of 90° means that the HCCH subunit monomer axis is perpendicular to the line X(1)…X(2). b

The rotationally resolved IR spectrum of the ternary complex of ethyne with carbonyl sulfide was recorded by a slit-jet tunable diode laser spectrometer in the ν1 fundamental region of the OCS monomer at about 2000 cm-1. The 18O and perdeuterated isotopic species were investigated in enriched samples. The lowest energy nonpolar complex was detected for the first time, whereas the higher energy polar form was already studied by microwave spectroscopy. The partial effective structure r0 of the nonpolar complex was determined from the ground-state rotational constants of four isotopic species under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Rezaei M, McKellar ARW, Moazzen-Ahmadi N (2011) Infrared spectra of the C2H2-(OCS)2 van der Waals complex: Observation of a structure with C2 symmetry. J Phys Chem A 115(38):10416-10422

501 CAS RN: 108-31-6 MGD RN: 679480 GED combined with MW and augmented by QC computations

2,5-Furandione Maleic anhydride C 4H 2O 3 C2v O

Bonds C(2)–C(3) C(3)=C(4)

r see [Å] a 1.485(1) 1.332(1) b

rg [Å] a 1.495(1) 1.341(1)

O

O

410

6 Molecules with Four Carbon Atoms

C–O(1) C=O C–H

1.386(1) b 1.192(1) 1.078 c

Bond angles C–C=C O=C–C C(3)=C(4)–H O(1)–C–C C–O(1)–C O=C–O(1)

θ see [deg] a

1.396(1) 1.197(1) 1.098 c

107.8(1) 129.2(2) 129.7 c 108.2(1) d 107.9(1) d 122.6(1) d

Copyright 2010 with permission from Elsevier [a].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Difference between the C=C and C−O bond lengths was assumed at the value from MP2/aug-cc-pVTZ computation. c Assumed at the value from computation as indicated above. d Dependent parameter. b

The GED experiments were carried out at the nozzle temperature of 340(5) K. The semiexperimental equilibrium structure of the title molecule was determined by simultaneous fitting to the GED intensities and MW ground-state rotational constants. MW data were taken from Ref. [b]. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re and rotational constants, ∆Be = Be − B0, were calculated from the MP2/aug-cc-pVTZ quadratic and cubic force constants taking into account nonlinear kinematic effects. a. Vogt N, Altova EP, Karasev NM (2010) Equilibrium structure of maleic anhydride from gas-phase electron diffraction (GED) and quantum-chemical studies. J Mol Struct 978 (1-3):153-157 b. Stiefvater OL (1977) Complete structure of maleic anhydride by DRM microwave spectroscopy. Z Naturforsch 32a:1480-1489 C2v

MW augmented by ab initio calculations Bonds C(2)–C(3) C(3)=C(4) O(1)–C(2) C(2)=O C(3)–H

r0 [Å] a 1.487(3) 1.342(4) 1.390(2) 1.195(2) 1.074(1)

r m [Å] a 1.483(2) 1.335(3) 1.387(1) 1.195(1) 1.077(1)

r see [Å] a 1.4849(5) 1.3324(5) 1.3848(3) 1.1894(2) 1.0765(2)

Bond angles C(2)–C(3)=C(4) O=C(2)–C(3) H–C(3)=C(4) O(1)–C(2)–C(3) C(2)–O(1)–C(5) O(1)–C(2)=O

θ0 [deg] a

θ (1) [deg] a m

θ see [deg] a

107.8(1) 129.7(2) 129.9(1) 108.0(1) 108.2(2) 122.3(3)

Reproduced with permission of SNCSC [c].

(1)

107.9(1) 129.6(1) 130.0(1) 108.1(1) 108.1(1) 122.3(1)

107.96(1) 129.68(3) 129.90(1) 107.78(2) 108.52(2) 122.55(4)

6 Molecules with Four Carbon Atoms a

411

Parenthesized uncertainties in units of the last significant digit.

structures were obtained from the previously published ground-state rotational of ten isotopic The r0 and r (1) m species. The semiexperimental equilibrium structure was determined by taking into account rovibrational corrections, ΔBe = Be ‒ B0, computed with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. The semiexperimental r see structure was found to be much closer to the computed structure of CCSD(T)_ae/ccpwCVQZ quality than the experimental r0 and r (1) structures. m c. Vogt N, Demaison J, Rudolph HD (2011) Equilibrium structure and spectroscopic constants of maleic anhydride. Struct Chem 22(2):337-343

502 CAS RN: 1584221-69-1 MGD RN: 411426 MW supported by ab initio calculations

(η2-Ethyne)silver acetylide Ethyne – silver acetylide (1/1) C4H3Ag H C2v C Ag

Distances rb C≡C c

r0 [Å] a 2.2096(2) 1.2327(3)

Bond angle C≡C–H c

θ0 [deg] a

C

C

H

C H

185.88(8)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Distance between Ag and the midpoint of the C≡C bond in the ethyne subunit. c In the ethyne subunit. b

The rotational spectra of the binary complex of silver acetylide with acetylene were recorded in a supersonic jet both by a chirped-pulse and a Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The compound was produced by a gas phase reaction of laser-ablated silver with acetylene. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 109 Ag, 13C3. D3, 109Ag/13C3 and 109Ag/D3). Stephens SL, Zaleski DP, Mizukami W, Tew DP, Walker NR, Legon AC (2014) Distortion of ethyne on coordination to silver acetylide, C2H2⋅⋅⋅AgCCH, characterized by broadband rotational spectroscopy and ab initio calculations. J Chem Phys 140(12):124310/1-124310/13 [http://dx.doi.org/10.1063/1.4868035]

503 CAS RN: 51-21-8 MGD RN: 328378 GED combined with MS and augmented by DFT computations

5-Fluoro-2,4(1H,3H)-pyrimidinedione 5-Fluorouracil C4H3FN2O2 Cs

412

6 Molecules with Four Carbon Atoms

Bonds N(1)–C(2) C(2)–N(3) N(3)–C(4) C(4)–C(5) C(5)=C(6) C–F C(6)–N(1) C=O N(1)–H N(3)–H C(6)–H

ra [Å] a,b 1.394(2) 1 1.394(2) 1 1.410(2) 1 1.464(2) 1.355(2) 2 1.342(2) 2 1.343 1.217(1) 1.014 c 1.014 c 1.083 c

Bond angles N(1)–C(2)–N(3) C(2)–N(3)–C(4) N(3)–C(4)–C(5) C(4)–C(5)=C(6) C(5)–C(6)–N(1) C(6)–N(1)–C(2) O(7)=C(2)–N(1) O(8)=C(4)–C(5) O(8)=C(4)–N(3) F–C(5)=C(6) F–C(5)–C(4) C(2)–N(1)–H C(2)–N(3)–H C(5)=C(6)–H

θa [deg] a,b

O F HN

N H

O

112.4(1) 3 128.6(1) 3 111.8(1) 3 121.3(1) 3 121.8(3) 124.0(2) 125.8 128.7 119.5 122.8(5) 115.9 115.2 c 115.3 c 122.3 c

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are presumably estimated total errors. Parameters with equal superscripts were refined in one group. Differences between parameters in each group were assumed according to results of B3LYP/6-31G* computation. c Adopted from computation as indicated above. b

The temperature of the GED experiment was not stated. Naumov VA, Shlykov SA, Potanin AV (2009) 5-fluorouracyl. Molecular structure in the gas phase. Russ J Gen Chem/Zh Obshch Khim 79/79 (3/3):475-481 / 486-492

504 CAS RN: 2253-02-3 MGD RN: 428088 MW supported by ab initio calculations

1,1,2,2,3-Pentafluorocyclobutane C4H3F5 C1 F

F

F

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(1)

a

rs [Å] 1.57(2) 1.56(1) 1.511(6) 1.52(1)

F F

6 Molecules with Four Carbon Atoms

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(1) C(4)–C(1)–C(2)

θs [deg] a

Dihedral angle C(1)–C(2)–C(3)–C(4)

τs [deg] a

413

87.0(8) 87.6(6) 90.4(5) 86.8(9)

21.1

Copyright 2014 with permission from Elsevier.

a

Uncertainties given in parentheses are Costain errors in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by a chirped-pulsed FTMW spectrometer in the frequency region between 7.8 and 16.2 GHz. The rs structure of the ring skeleton was determined from the ground-state rotational constants of five isotopic species (main and four 13C). Cooke SA, Minei AJ (2014) The pure rotational spectrum of 1,1,2,2,3-pentafluorocyclobutane and applications of singular value decomposition signal processing. J Mol Spectrosc 306:37-41

505 CAS RN: 28523-86-6 MGD RN: 143685 MW supported by QC calculations

1,1,1,3,3,3-Hexafluoro-2-(fluoromethoxy)propane Sevoflurane C4H3F7O C1 F

F

Bonds C(1)–C(2) C(2)–C(3) C(2)–O C(4)–O

r0 [Å] a 1.532(34) 1.515(53) 1.390(76) 1.398(32)

rs [Å] a 1.470(40) 1.403(15) 1.554(28) 1.377(6)

Bond angles C(1)–C(2)–C3 C(1)–C(2)–O C(3)–C(2)–O C(2)–O–C(4)

θ0 [deg] a

θs [deg] a

Dihedral angles C(1)–C(2)–O–C(4) C(3)–C(2)–O–C(4)

τ0 [deg] a

τs [deg] a

115(5) 109(4) 109(2) 117(2)

-102.3(10) 130.6(14)

O

F

F

F F

124(4) 103(3) 107(3) 121(1)

-99(4) 129(2)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of sevoflurane was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 8 and 26 GHz.

F

414

6 Molecules with Four Carbon Atoms

From the ground-state rotational constants of six isotopic species (main, four 13C and 18O) the partial r0 and rs structures were determined. Lesarri A, Vega-Toribio A, Suenram RD, Brugh DJ, Grabow JU (2010) The conformational landscape of the volatile anesthetic sevoflurane. Phys Chem Chem Phys 12(33):9624-9631

506 CAS RN: 541-59-3 MGD RN: 665950 MW augmented by DFT calculations

1H-Pyrrol-2,5-dione Maleimide C4H3NO2 C2v

Bonds C(2)=C(2ꞌ) C(2)–H C(1)–C(2) C(1)=O C(1)–N N–H

r0 [Å] a 1.374 1.078 b 1.499 1.205 b 1.389 1.006 b

Bond angles H–C(2)=C(2ꞌ) H–C(2)–C(1) C(1)–C(2)=C(2ꞌ) C(2)–C(1)=O C(2)–C(1)–N O=C(1)–N C(1)–N–C(1ꞌ) C(1)–N–H

θ0 [deg] a

O

O

N H

129 123 108 127 106 126 112 124

Copyright 2015 with permission from Elsevier.

a b

Uncertainties were not given in the original paper. Assumed at the value from B3LYP/aug-cc-pVTZ calculation.

The rotational spectra of the title compound were recorded by a pulsed-beam Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 12 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, two 13C and D). The rotational constants were found to be consistent with a planar structure of the molecule. No evidence for large amplitude motion of the hydrogen in the imino group was observed. Pejlovas AM, Oncer O, Kang L, Kukolich SG (2016) Microwave spectrum and gas phase structure of maleimide. J Mol Spectrosc 319(1):26-29

507 CAS RN: MGD RN: 210874 MW supported by ab initio calculations

1-Chloro-1-fluoroethene - ethyne (1/1) 1-Chloro-1-fluoroethylene – acetylene (1/1) C4H4ClF H Cl Cs H H

F

C

C

H

6 Molecules with Four Carbon Atoms

Distances H(1)…F rb

r0 [Å] a 2.623(11) 2.977(17)

Angles C–F…H(1)

θ0 [deg] a

αc

415

124.30(70) 52.82(28)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Distance between H(2) and the midpoint of the C≡C bond. c Deviation of C–H⋅⋅⋅F from linearity. b

The rotational spectra of the binary complex of 1-chloro-1-fluoroethene with ethyne were recorded by a pulsedjet Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 21 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 37Cl, 13C2, three D and 37Cl/13C2) under the assumption that the structural parameters were not changed upon complexation. Leung HO, Marshall MD, Grimes DD (2011) Rotational spectroscopy and molecular structure of the 1-chloro-1fluoroethylene-acetylene complex. J Chem Phys 134(3):034303/1-034303/9 doi:10.1063/1.3517494

508 CAS RN: MGD RN: 477821 MW supported by ab initio calculations

(Z)-1-Chloro-2-fluoroethene – ethyne (1/1) cis-1-Chloro-2-fluoroethylene – acetylene (1/1) C4H4ClF Cs H

H H

Distances Cl…H rb

r0 [Å] a 3.069(9) 2.7815(8)

Angles C–Cl…H C–H…Cl c

θ0 [deg] a

Cl

C

C

H

F

87.8(1) 117.6(4)

Reprinted with permission. Copyright 2017 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit. Distance between H and the midpoint of the C≡C bond. c Angle between hydrogen bond and the C≡C bond. b

The rotational spectrum of the binary complex of cis-1-chloro-2-fluoroethylene with acetylene was recorded in a supersonic jet by broadband chirped-pulse FTMW and narrow band Balle-Flygare type FTMW spectrometers in the frequency region between 5.5 and 20.8 GHz. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, 37 Cl, three 13C, 13C2, 37Cl/13C and 37Cl/13C2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation.

416

6 Molecules with Four Carbon Atoms

Leung HO, Marshall MD, Khan ND (2017) The microwave spectrum and molecular structure of (Z)-1-chloro-2fluoroethylene-acetylene: Demonstrating the importance of the balance between steric and electrostatic interactions in heterodimer formation. J Phys Chem A 121(30):5651-5658

509 CAS RN: 128-09-6 MGD RN: 156195 GED augmented by QC computations

1-Chloro-2,5-pyrrolidinedione N-Chlorosuccinimide C4H4ClNO2 C2v Cl

O

Bonds N–Cl C–N C(2)–C(3) C(3)–C(4) C=O C–H

re [Å] a 1.672(3) 1.401(2) b 1.515(2) b 1.530(2) b 1.201(2) 1.106(18)

Bond angles C–N–C C–C–N C–C–C O=C–N

θe [deg] a,c

Dihedral angle C–C–C–C

τe [deg]

N

O

114.7(5) 106.8(3) 105.9(2) 123.7(5)

0.0 d

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Refined in one group. Differences between parameters in each group were assumed at the values from MP2/ccpVTZ computation. c All C–C–H angles were assumed at the values from computation as indicated above. d Assumed according to computation as indicated above. b

According to predictions of MP2 and B3LYP computations with several basis sets (up to 6-311G(3df,2pd) and cc-pVTZ), the title molecule has a planar skeleton (C2v overall symmetry). The GED analysis confirmed the planarity of the succinimide ring and the bond angle configuration around the nitrogen atom (within large experimental uncertainties). The planarity of succinimide ring was explained by influence of two carbonyl groups with the Csp2 atoms, which require enlarging of the adjusted ring angles and thus stabilize the planar ring conformation even though the repelling of the methylene groups try to disturb the planarity of the C–C–C–C unit. The GED experiment was carried out at Tnozzle = 389 K. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP/6-31G(df,p) scaled quadratic and cubic force constants taking into account non-linear kinematic effects. Vishnevsky YV, Vogt N, Korepanov VI, Ivanov AA, Vilkov LV, Kuznetsov VV, Mahova NN (2009) Molecular structure of N-chlorosuccinimide studied by gas-phase electron diffraction and quantum-chemical methods. Struct Chem 20 (3):435-442

6 Molecules with Four Carbon Atoms

510

417

(1E,3E)-1,4-Difluoro-1,3-butadiene trans,trans-1,4-Difluoro-1,3-butadiene

CAS RN: 35694-31-6 MGD RN: 215440 MW augmented by ab initio calculations

C4H4F2 C2h F

F

Bonds C(2)–C(3) C(1)=C(2) C(2)–H C–F C(1)–H

r see [Å] a 1.4502(10) 1.3301(7) 1.0824(10) 1.3391(8) 1.0812(10)

Bond angles C–C=C C(3)–C(2)–H C(1)=C(2)–H C(2)–C(1)–F C(2)–C(1)–H

θ see [deg] a

121.91(9) 119.26(10) 118.83(13) 121.31(4) 125.77(7)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties are standard deviations in units of the last digit.

The semiexperimental equilibrium structure r see of the title molecule was determined by the mixed estimated method from the previously published experimental ground-state rotational constants of six isotopic species by taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Demaison J, Császár AG, Groner P, Rudolph HD, Craig NC (2013) Semiexperimental equilibrium structures for cis,cis- and trans,trans-1,4-difluorobutadiene by the mixed estimation method and definitive relative energies of the isomers. J Phys Chem A 117(49):13166-13175

511 CAS RN: 35694-30-5 MGD RN: 145562 MW augmented by ab initio calculations

(1E,3Z)-1,4-Difluoro-1,3-butadiene cis,trans-1,4-Difluorobutadiene C4H4F2 Cs F F

Bonds C(1)–H(1) C(2)–H(2) C(3)–H(3) C(4)–H(4) C(1)=C(2) C(2)–C(3) C(3)=C(4) C(1)–F(1) C(4)–F(4)

r [Å] 1.0807 1.0800 1.0804 1.0786 1.3297 1.4469 1.3302 1.3385 1.3425 se e

a

418

6 Molecules with Four Carbon Atoms

θ see [deg] a

Bond angles C(1)=C(2)–C(3) C(2)–C(3)=C(4) H(1)–C(1)=C(2) H(2)–C(2)–C(3) H(3)–C(3)–C(2) H(4)–C(4)=C(3) F(1)–C(1)=C(2) F(4)–C(4)=C(3)

121.56 124.19 125.60 119.45 119.45 125.67 121.52 121.51

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Uncertainties were not given in the original paper.

The semiexperimental equilibrium structure r see was determined from the previously published experimental ground–state rotational constants taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Demaison JF, Craig NC (2011) Semiexperimental equilibrium structure of cis,trans-1,4-difluorobutadiene by the mixed estimation method. J Phys Chem A 115(27):8049-8054

512 CAS RN: 35694-29-2 MGD RN: 215648 MW augmented by ab initio calculations Bonds C(2)–C(3) C(1)=C(2) C(2)–H C–F C(1)–H

r e [Å] a 1.4504(6) 1.3300(5) 1.0796(6) 1.3423(4) 1.0787(6)

Bond angles C=C–C C(3)-C(2)–H C(1)=C(2)–H C(2)=C(1)–H C(2)=C(1)–H

θ see [deg] a

(1Z,3Z)-1,4-Difluoro-1,3-butadiene cis,cis-1,4-Difluoro-1,3-butadiene C4H4F2 C2h F

se

F

123.68(5) 119.18(6) 117.14(8) 121.64(4) 125.58(6)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. se

The semiexperimental equilibrium structure r e of the title molecule was determined from the previously published experimental ground-state rotational constants of six isotopic species by taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields.

6 Molecules with Four Carbon Atoms

419

Demaison J, Császár AG, Groner P, Rudolph HD, Craig NC (2013) Semiexperimental equilibrium structures for cis,cis- and trans,trans-1,4-difluorobutadiene by the mixed estimation method and definitive relative energies of the isomers. J Phys Chem A 117(49):13166-13175

513 CAS RN: MGD RN: 549218 MW supported by ab initio calculations

1,1,1,2-Tetrafluoroethane dimer C4H4F8 C1 F F a

a

Distances C(1)…C(9) F(5)...H(6) H(4)...F(11) H(4)...F(8) H(3)...F(8) C(1)–C(2) C(9)–C(10)

r0 [Å] 3.833(7) 2.570(7) b 2.607(7) b 3.005(7) b 3.000(7) b

rs [Å] 3.671(3)

Angles C(9)…C(1)–C(2) C(10)–C(9)…C(1) F(5)…H(6)–C(9) F(11)…H(4)–C(1) F(8)…H(3)–C(1) F(8)…H(4)–C(1)

θ0 [deg] a

θs [deg] a

144.3(3) 88.6(2) 119(1) b 125(1) b 91(1) b 81(1)

F

F

2

1.592(2) 1.459(6)

148.9(4) 91.0(2)

τs [deg] a

Dihedral angle C(10)–C(9)…C(1)–C(2)

-179(1)

Reprinted with permission. Copyright 2017 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the dimer of 1,1,1,2-tetrafluoroethane was recorded in a pulsed supersonic jet by an FTMW spectrometer in the frequency region between 2 and 20 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main and four 13C) under the assumption that the structural parameters of the monomer subunit were not changed upon complexation. The partial rs structure was obtained for the carbon skeleton. Li X, Zheng Y, Chen J, Grabow JU, Gou Q, Xia Z, Feng G (2017): Weak hydrogen bond network: A rotational study of 1,1,1,2-tetrafluoroethane dimer. J Phys Chem A 121(41):7876-7881 514 CAS RN: 110-61-2 MGD RN: 874501 MW supported by QC calculations

Butanedinitrile Succinonitrile C4H4N2 C2 (synclinal) N C

C

Bonds

rs [Å]

a

N

420

6 Molecules with Four Carbon Atoms

C(2)–H(7) C(2)–H(8) C(2)–C(3) C(1)–C(2) C(1)≡N(5)

1.1227(33) 1.1111(51) 1.5297(51) 1.4558(133) 1.1627(138)

Bond angles H(7)–C(2)–C(3) H(7)–C(2)–H(8) H(8)–C(2)–C(3) C(1)–C(2)–C(3) N(5)≡C(1)–C(2)

θs [deg] a

110.10(53) * 109.05(86) 108.37(61) 112.65(101) 178.8

Dihedral angle τs [deg] a C(1)–C(2)–C(3)–C(4) 65.94(230) Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of succinonitrile were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 2 and 26.5 GHz and by a Stark-modulation free-jet millimeterwave spectrometer in the frequency region between 48 and 87 GHz. Only the synclinal conformer was observed. In the millimeter-wave range the singly 13C- and 15N-substituted isotopic species were investigated in natural abundance together with the mono-deuterated species. The rs structure was determined from the ground-state rotational constants of six isotopic species (main, two 13 15 C, N and two D). Jahn MK, Grabow JU, Godfrey PD, McNaughton D (2014) Substituent steering of dihedral angles around single bonds: the case of succinonitrile. Phys Chem Chem Phys 16(5):2100-2105

515 CAS RN: 289-80-5 MGD RN: 974051 MW augmented by ab initio calculations

Pyridazine C4H4N2 C2v N

a

a

Bonds C(4)–C(5) C(4)–H C(3)–C(4) C(3)–H N(2)–C(3)

r0 [Å] 1.3816(131) 1.0792(29) 1.4011(94) 1.0816(21) 1.3328(97)

rs [Å] 1.3756(50) 1.0829(50) 1.4012(50) 1.0832(50) 1.3336(50)

Bond angles H–C(4)–C(5) C(3)–C(4)–C(5) H–C(3)–C(4) N(2)–C(3)–C(4)

θ0 [deg] a

θs [deg] a

122.34(35) 116.82(24) 121.28(43) 123.92(31)

Reproduced with permission of AIP Publishing.

122.66(50) 116.88(50) 120.87(50) 123.65(50)

a

r [Å] 1.3761(16) 1.0802(4) 1.3938(12) 1.0810(3) 1.3302(12) se e

θ see [deg] a 122.37(4) 116.85(3) 121.35(6) 123.86(4)

N

6 Molecules with Four Carbon Atoms a

421

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of pyridazine were recorded by a millimeter- and submillimeter-wave spectrometer in the frequency region between 235 and 360 GHz. The ground and several first excited vibrational states were investigated for the main isotopic species. The r0 and rs structures were obtained from the ground-state rotational constants of fourteen isotopic species (main, two 13C, 15N, two D, four D2, two D3, D4 and 13C/D). The semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections calculated with the CCSD(T)/ANO0 harmonic and anharmonic (cubic) force fields. Esselman BJ, Amberger BK, Shutter JD, Daane MA, Stanton JF, Woods RC, McMahon RJ (2013) Rotational spectroscopy of pyridazine and its isotopologs from 235-360 GHz: Equilibrium structure and vibrational satellites. J Chem Phys 139(22):224304/1-224304/13 [http://dx.doi.org/10.1063/1.4832899]

516 CAS RN: 289-95-2 MGD RN: 941449 MW augmented by DFT calculations

Pyrimidine C4H4N2 C2v N

Bonds N(1)–C(2) N(1)–C(6) C(4)–C(5) C(2)–H C(4)–H C(5)–H

r e [Å] a 1.3331(3) 1.3349(6) 1.3874(4) 1.0820(23) 1.0843(17) 1.0799(23)

Bond angles N(1)–C(2)–N(3) C(6)–N(1)–C(2) N(1)–C(6)–C(5) C(4)–C(5)–C(6) N(1)–C(2)–H C(5)–C(4)–H C(4)–C(5)–H

θ see [deg] a

se

N

127.364(38) 115.712(21) 122.276(19) 116.661(36) 116.318(19) 121.24(20) 121.670(18)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. se

The semiexperimental equilibrium structure r e was determined from the previously published ground-state rotational constants of five isotopic species. The rovibrational corrections, ΔBe = Be ‒ B0, were calculated with the B3LYP/6-311+G(3df,2pd) harmonic and anharmonic (cubic) force fields. Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and sevenmembered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746

422

6 Molecules with Four Carbon Atoms

517 CAS RN: 66-22-8 MGD RN: 245327 MW augmented by QC calculations

2,4(1H,3H)-Pyrimidinedione Uracil C4H4N2O2 Cs O

Bonds N(1)–C(2) C(2)–N(3) N(3)–C(4) C(4)–C(5) C(5)=C(6) C(6)–N(1) C(2)=O C(4)=O N(1)–H N(3)–H C(5)–H C(6)–H

r see [Å] a 1.38163(65) 1.3763 1.39823(47) 1.45485(99) 1.34576(107) 1.37160(100) 1.21015(26) 1.21268(34) 1.0004(70) 1.0110(96) 1.0766 b 1.0793 b

Bond angles C(2)–N(1)–C(6) N(1)–C(6)=C(5) C(6)=C(5)–C(4) C(5)–C(4)–N(3) C(4)–N(3)–C(2) N(3)–C(2)–N(1) N(1)–C(2)=O C(5)–C(4)=O C(2)–N(1)–H C(2)–N(3)–H C(6)=C(5)–H N(1)–C(6)–H

θ see [deg] a

HN

O

N H

123.394(35) 121.920(10) 119.501(20) 113.859(33) 127.947 113.379 123.878(54) 125.765(75) 115.22 b 115.52(40) 122.11 b 115.34 b

Reproduced with permission from the PCCP Owner Societies [a].

a b

Parenthesized uncertainties in units of the last significant digit. Constrained to the best estimated ab initio value.

The partial semiexperimental equilibrium structure was determined from the previously published ground-state rotational by taking into account rovibrational corrections calculated with the B3LYP/N07D harmonic and anharmonic (cubic) force fields. a. Puzzarini C, Barone V (2011) Extending the molecular size in accurate quantum-chemical calculations: the equilibrium structure and spectroscopic properties of uracil. Phys Chem Chem Phys 13(15):7189-7197 MW augmented by QC calculations Bonds N(1)–C(2) C(2)–N(3)

Cs

r e [Å] a 1.3810(6) 1.3749(7) se

6 Molecules with Four Carbon Atoms

N(3)–C(4) C(4)–C(5) C(5)=C(6) N(1)–C(6) C(2)=O C(4)=O

1.3991(6) 1.4548(6) 1.3429(7) 1.3722(7) 1.2101(4) 1.2186(4)

Bond angles C(2)–N(1)–C(6) N(1)–C(6)=C(5) C(4)–C(5)=C(6) C(5)–C(4)–N(3) C(4)–N(3)–C(2) N(1)–C(2)–N(3) N(3)–C(2)=O C(5)–C(4)=O C(2)–N(1)–H C(2)–N(3)–H C(6)–C(5)–H N(1)–C(6)–H N(1)–C(2)=O

θ see [deg] a

423

123.39(4) 121.90(2) 119.61(3) 113.75(4) 127.97(4) 113.38(4) 123.84(5) 125.84(4) 115.14(12) 115.62(13) 122.12(11) 115.39(6) 122.78(5)

Reprinted with permission. Copyright 2014 American Chemical Society [b].

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see was determined from the previously published ground-state rotational constants of ten isotopic species taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the B3LYP/6-311+G(3df,2pd) harmonic and anharmonic (cubic) force fields. b. Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and sevenmembered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746 GED augmented by ab initio computations Bonds N(1)–C(6) N(1)–C(2) C(2)–N(3) N(3)–C(4) C(5)=C(6) C(2)=O C(4)=O N(1)–H N(3)–H C(5)–H C(6)–H C(4)–C(5) Bond angles C(2)–N(1)–C(6) N(1)–C(2)–N(3)

r e [Å] a,b 1.374(2) 1 1.381(2) 1 1.379(2) 1 1.402(2) 1 1.339(18) 1.210(1) 2 1.212(1) 2 1.005(10) 3 1.009(10) 3 1.076(13) 3 1.079(13) 3 1.454(8) c se

θ see [deg] d 123.8(3) 113.0(2)

Cs

rg [Å] a 1.388(2) 1.395(2) 1.390(2) 1.413(2) 1.348(18) 1.215(1) 1.217(1) 1.025(10) 1.029(10) 1.096(13) 1.099(13) 1.465(8)

424

C(2)–N(3)–C(4) N(3)–C(4)–C(5) C(4)–C(5)=C(6) N(1)–C(6)=C(5) N(1)–C(2)=O N(3)–C(4)=O C(5)–C(4)=O C(6)–N(1)–H C(2)–N(3)–H C(6)=C(5)–H C(5)=C(6)–H

6 Molecules with Four Carbon Atoms

128.0(3) 113.6(3) 120.0(3) c 121.6(4) 122.6(5) 119.9(5) 126.5(6) c 121(6) 114(7) 122.0 e 126(4)

Copyright 2013 with permission from Elsevier [c].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the computed values of CCSD(T)_ae/cc-pwCVQZ quality. c Dependent parameter. d Parenthesized uncertainties in units of the last significant digit are 2σ values. e Taken from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle = 492(6) K. Vibrational corrections to the experimental internuclear distances, ∆re = ra− re, were calculated from the MP2_full/cc-pVTZ quadratic and cubic force constants taking into account non-linear kinematic effects. This study was carried out for benchmarking the equilibrium structure determinations by different experimental methods and CCSD(T) computations. c. Vogt N, Khaikin LS, Grikina OE, Rykov AN (2013) A benchmark study of molecular structure by experimental and theoretical methods: Equilibrium structure of uracil from gas-phase electron diffraction data and coupled-cluster calculations. J Mol Struct 1050:114-121 Cs

TRED

Bonds N(3)−C(2) N(3)−C(4) C(2)=O C(2)−N(1) N(1)−C(6) C(6)=C(5) C(5)−C(4) C(6)=O

r [Å] a,b 1.392 1.426 1.216 1.406 1.376 1.348 1.487 1.233

Reprinted with permission. Copyright 2009 American Chemical Society [d].

a b

Uncertainties were not given in the original paper. Type of parameters was not specified.

A vibrational temperature of 1400 K was deduced from the best fit to the experimental intensities. d. Gahlmann A, Park ST, Zewail AH (2009) Structure of isolated biomolecules by electron diffraction-laser desorption: Uracil and guanine. J Am Chem Soc 131 (8):2806-2808

6 Molecules with Four Carbon Atoms

518 CAS RN: 67-52-7 MGD RN: 327450 GED augmented by QC computations

425

2,4,6(1H,3H,5H)-Pyrimidinetrione Barbituric acid C4H4N2O3 C2v O

Bonds C(5)−C(6) N(1)–C(6) N(1)–C(2) C(6)=O C(5)−H N(1)−H C(2)=O

rh1 [Å] a 1.526(7) 1.393(4) b 1.396(4) b 1.210(2) 1.085 c 1.009 c 1.215(5) d

Bond angles C(4)–C(5)–C(6) N(1)–C(6)–C(5) C(5)–C(6)=O C(6)–C(5)–H C(6)–N(1)–H C(6)–N(1)–C(2) N(1)–C(2)–N(3) N(1)–C(2)=O N(1)–C(6)=O

θh1 [deg] a

HN

NH

O

O

117.4(7) 116.4(5) 122.6(5) 108.0 c 116.9 c 127.1(6) d 115.7(9) d 122.1(4) d 121.0(3) d

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Difference between the N–C bond lengths was assumed at the value from MP2/cc-pVTZ calculation. c Assumed at the value from computation as above. d Dependent parameter. b

According to predictions of B3LYP and MP2_full computations (with cc-pVTZ basis set), the equilibrium configuration of the title molecule has C2v point-group symmetry. The molecule was predicted to be flexible due to low frequency of the out-of-plane vibration of the methylene carbon atom (25 cm–1(MP2)). The GED experiment was carried out at Tnozzle ≈ 463 K. In the GED analysis, the dynamic model based on the PEF with constants from MP2 calculation (V2 = 35.1 kJ mol-1, V4 = -8.6 kJ mol-1) was applied for description of the large-amplitude ring-puckering motion. Structural differences between the pseudo-conformers were also fixed to the calculated values. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated with the MP2 harmonic force constants. Dorofeeva OV, Marochkin II, Karasev NM, Shishkov IF, Oberhammer H (2011) Molecular structure, conformation, and large amplitude motion of barbituric acid as studied by gas-phase electron diffraction and quantum chemical calculations. Struct Chem 22 (2):419-425

519 CAS RN: 110-00-9 MGD RN: 651888 MW augmented by ab initio calculations

Furan C4H4O C2v

426

6 Molecules with Four Carbon Atoms

Bonds C(2)–O C(2)–H C(2)=C(3) C(3)–C(3') C(3)–H

r e [Å] a 1.3594(7) 1.0735(7) 1.3552(8) 1.432(2) b 1.0753(6)

Bond angles C(2)–O–C(2) O–C(2)–H O–C(2)=C(3) C(3)=C(2)–H C(2)=C(3)–C(3') C(2)=C(3)–H C(3')–C(3)–H

θ see [deg] a

se

O

106.63(6) 115.88(6) 110.66(9) 133.46(9) b 106.03(7) b 126.32(11) 127.66(5)

Reprinted with permission. Copyright 2011 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. se

The semiexperimental equilibrium structure r e was determined from the previously published experimental ground-state rotational constants of nine isotopic species taking into account the rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Demaison J, Császár AG, Margulès LD, Rudolph HD (2011) Equilibrium structures of heterocyclic molecules with large principal axis rotations upon isotopic substitution. J Phys Chem A 115(48):14078-14091

520 CAS RN: 108-30-5 MGD RN: 438186 GED augmented by QC computations

Dihydro-2,5-furandione Succinic anhydride C 4H 4O 3 C2v (see comment) O

Bonds C(2)–C(3) C(3)–C(4) C=O(6) C–H C–O(1)

r e [Å] a 1.514(1) b 1.524(1) b 1.188(1) 1.085(6) 1.383(3)

Bond angles C–O(1)–C O(1)–C–C O(6)=C–O(1) C(2)–C(3)–C(4) C(2)–C(3)–H

θ see [deg] c

se

110.9(2) d 110.1(2) d 121.5(2) 104.4(1) 106.9(11)

O

O

6 Molecules with Four Carbon Atoms

Dihedral angles O(1)–C–C–C C–O(1)–C–C C–O(1)–C=O C–C–C–C

427

τ see [deg] ±121.8 e 0.0 f 180.0 f 0.0 f

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error. b The C–C bond lengths were refined in one group, their difference was assumed at the computed value of CCSD(T)_ae/cc-pwCVQZ quality (see comment below). c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Derived value. e Assumed at the value computed at the level of theory as indicated above. f According to assumed C2v symmetry (see comment). According to predictions of B3LYP/cc-pVTZ computations, the heavy-atom skeleton of the title molecule is planar (overall C2v symmetry), whereas it is non-planar (with the C–C–C–C torsional angle up to 11°) according to MP2 computations with various basis sets. It was revealed that the non-planarity of the ring decreases with increase of quality of ab initio computations. The structure optimization at the CCSD(T)_ae/cc-pwCVTZ level of theory with the following extrapolation to quadruple-ζ basis set (at the MP2 level) revealed the C2v symmetry of the molecule. The GED experiment was carried out at 370(3) K. In the GED analysis, the molecule was assumed to have C2v point-group symmetry. Large-amplitude ring-twisting motion was described by a model of pseudo-conformers distributed according to PES profile from B3LYP/cc-pVTZ calculation. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from the B3LYP/cc-pVTZ quadratic and cubic force constants taking into account non-linear kinematic effects. Vogt N, Altova EP, Ksenafontov DN, Rykov AN (2015) Benchmark study of molecules with large-amplitude ring-twisting motion: accurate equilibrium structure of succinic anhydride from gas electron diffraction data and coupled-cluster computations. Struct Chem 26 (5-6):1481-1488

521 CAS RN: 110-17-8 MGD RN: 309770 GED augmented by QC computations

(2E)-2-Butenedioic acid Fumaric acid C 4H 4O 4 Cs (s-trans,s-cis) C2h (s-cis,s-cis) C2h (s-trans,s-trans) O

Bonds C(3)=C(2) C(2)–C(1) C(3)–C(4) C(1)–O(5) C(4)–O(7) C(1)=O(6) C(4)=O(8) C(2)–H C(3)–H O(5)–H O(7)–H

s-trans,s-cis 1.338(2) 1.484(2) 1.489(2) 1.355(2) 1.355(2) 1.209(2) 1.207(2) 1.096 1.094 0.982 0.982

ra [Å] s-cis,s-cis 1.337(2) 1.488(2) 1.354(2) 1.208(2) 1.096 0.982

a

HO

s-trans,s-trans 1.339(2) 1.485(2)

OH O

1.354(2) 1.209(2) 1.095 0.982 s-trans,s-cis

428

6 Molecules with Four Carbon Atoms

Bonds C(3)=C(2) C(2)–C(1) C(3)–C(4) C(1)–O(5) C(4)–O(7) C(1)=O(6) C(4)=O(8) C(2)–H C(3)–H O(5)–H O(7)–H

s-trans,s-cis 1.331(3) 1 1.473(3) 2 1.479(3) 2 1.345(3) 1 1.344(3) 1 1.205(3) 3 1.204(3) 3 1.080 c 1.079 c 0.967 c 0.968 c

r see [Å] a,b s-cis,s-cis s-trans,s-trans 1.330(3) 1 1.332(3) 1 1.475(3) 2 2 1.477(3) 1.344(3) 1 1 1.344(3) 1.205(3) 3 3 1.204(3) 1.079 c 1.080 c 0.967 c c 0.968

Bond angles C(1)–C(2)=C(3) C(4)–C(3)=C(2) O(5)–C(1)–C(2) O(7)–C(4)–C(3) O(6)=C(1)–O(5) O(8)=C(4)–O(7) C(2)–C(1)=O(6) C(3)–C(4)=O(8)

s-trans,s-cis 123.9(2) 4 120.0(2) 4 116.1(4) 5 113.8(4) 5 122.8(1) 6 123.1(1) 6 121.1 d 123.1 d

Copyright 2010 with permission from Elsevier [a].

θ see [deg] a,b

s-cis,s-cis

120.3(2) 4 113.9(4)

5

123.1(1)

6

123.0

d

s-cis,s-cis

s-trans,s-trans 123.5(2) 4 116.2(4) 5 122.8(1) 6 120.9 d

s-trans,s-trans

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 3σ and a systematic error of 0.001r; for r see bond lengths, uncertainties include additionally the estimated errors in the vibrational corrections. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were adopted from MP2/cc-pVQZ calculation. c Adopted from calculation at the level of theory as indicated above. d Dependent parameter. The GED experiment was carried out at Tnozzle = 480 K. The title compound was found to exist as an approximately equimolar mixture of three conformers, s-trans,s-cis, s-cis,s-cis and s-trans,s-trans, characterized by antiperiplanar and/or synperiplanar O=C−C=C dihedral angles. This conclusion confirmed the results obtained from the measurements of IR band intensities [b], which revealed the conformers to be almost equal energetically. According to predictions of MP2 and B3LYP computations (with cc-pVTZ basis set), the s-trans,s-cis and strans,s-trans conformers are higher in energy than the s-cis,s-cis conformer by 1.6 and 3.0 kJ mol−1 (MP2), respectively. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from the MP2/cc-pVTZ quadratic and cubic force constants taking into account non-linear kinematic effects. a. Vogt N, Abaev MA, Karasev NM (2011) Molecular structure and stabilities of fumaric acid conformers: Gas phase electron diffraction (GED) and quantum-chemical studies. J Mol Struct 987(1-3):199-205 b. Maçôas EMS, Fausto R, Lundell J, Pettersson M, Khriachtchev L, Räsänen M (2001) A matrix isolation spectroscopic and quantum chemical study of fumaric and maleic acid. J Phys Chem A 105:3922-3933

522 CAS RN: 1346556-57-7 MGD RN: 151095

2-Propynoic acid – formic acid (1/1) Propiolic acid – formic acid (1/1) C 4H 4O 4

6 Molecules with Four Carbon Atoms

429

MW supported by ab initio calculations

Cs O

O

Distances H(1)…O(4) H(2)…O(2) O(1)…O(4) O(2)...O(3) H(3)–C(3) C(2)≡C(3) C(1)–C(2) C(1)=O(2) C(1)–O(1) O(1)–H(1) H(2)–O(3) O(3)–C(4) C(4)=O(4) C(4)–H(4) C(1)...C(4) Rcm b

r0 [Å] a 1.64 1.87 2.59 2.80 1.05 1.21 1.45 1.20 1.35 0.97 0.97 1.34 1.20 1.10 3.822 3.8720

Angles O(2)=C(1)–O(1) C(1)–O(1)–H(1) H(2)–O(3)–C(4) O(3)–C(4)=O(4) O(3)–C(4)–H(4)

θ0 [deg] a

C

OH

H

OH

C H

124 106 106 125 112

Reprinted with permission. Copyright 2013 American Chemical Society.

a b

Uncertainties were not given in the original paper. Distance between the centers of mass of the monomer subunits.

The rotational spectra of two partially deuterated species of the binary complex of propiolic acid with formic acid were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 4.9 and 15.4 GHz. The partial r0 structure was obtained from the determined ground-state rotational constants combined with previously published rotational constants of five further isotopic species under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Kukolich SG, Mitchell EG, Carey SJ, Sun M, Sargus BA (2013) Microwave structure for the propiolic acidformic acid complex. J Phys Chem A 117(39):9525-9530

523 CAS RN: 855938-67-9 MGD RN: 391287 MW supported by ab initio calculations

Chloroethene – ethyne (1/1) Vinyl chloride – acetylene (1/1) C4H5Cl Cs H

Cl H

Distances Cl…H(2) H(1)…X b

r0 [Å] a 3.01(1) 2.939(4)

H

H

C

C

H

430

Angles C(1)–Cl…H(2) Cl…H(2)–C(2)

6 Molecules with Four Carbon Atoms

θ0 [deg] a 88.7(2) 121.5(5)

Reprinted with permission. Copyright 2013 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. X is the center of the C≡C bond.

The rotational spectrum of the binary complex of vinyl chloride with acetylene was recorded in a supersonic jet by chirped-pulse FTMW and Balle-Flygare type FTMW spectrometers in the frequency region between 5.8 and 20.7 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 37 Cl, 13C2 and 37Cl/13C2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Leung HO, Marshall MD, Feng F (2013) Microwave spectrum and molecular structure of vinyl chlorideacetylene, a side binding complex. J Phys Chem A 117(50):13419-13428

524 CAS RN: 625-24-1 MGD RN: 537084 GED augmented by QC computations

Acetic acid 2,2,2-trichloroethyl ester 2,2,2-Trichloroethyl acetate C4H5Cl3O2 C1 (syn-gauche) Cs (syn-anti) O

Bonds O(1)=C(3) C(3)–C(4) C(3)–O(2) O(2)–C(1) C(1)–C(2) C(2)–Cl C(4)–H C(1)–H

re [Å] a 1.218(5) 1.493(3) 1.346(5) 1.411(5) 1.517(4) 1.769(1) b 1.100(6) b,c 1.097(6) b,c

Bond angles O(1)=C(3)–C(4) O(1)=C(3)–O(2) C(3)–O(2)–C(1) O(2)–C(1)–C(2)

θe [deg] a

Dihedral angle O(2)–C(1)–C(2)–Cl(1)

τe [deg] a

126.7(15) 122.1(10) 113.5(10) 107.3(7)

179.3(15) d

Table 5 reproduced with permission from de Gruyter, Berlin.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Average value. c Difference between the C(4)–H and C(1)–H bond lengths was assumed. b

Cl H 3C

O Cl Cl

6 Molecules with Four Carbon Atoms d

431

Thermally-averaged value.

Various MP2 and B3LYP computations predicted the existence of two conformers, syn-anti and syn-gauche, characterized by the synperiplanar O(1)=C(3)–O(2)–C(1) dihedral angles and differing in the magnitude of the the C(3)–O(2)–C(1)–C(2) torsional angle (antiperiplanar vs. anticlinal). The syn-anti conformer was predicted to be lower in energy than the syn-gauche conformer by 1.2 kJ mol-1 and separated from it by the barrier height of 0.3 kJ mol-1 only (B3LYP-D3/6-311++G(d,p)). The corresponding mole fraction of the lowest energy conformer was calculated to be 61 %. The GED experiment was carried out at Tnozzle =323 K. The best fit to the experimental intensities was obtained using dynamic model based on the PEF from computations at the level of theory as indicated above. The percentage of the syn-anti conformer was refined to be 44(9) %. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2/6311G(d,p) quadratic and cubic force fields taking into account non-linear kinematic effects. Structural parameters were presented for the syn-anti conformer. Blomeyer S, Reuter CG, Gil DM, Tuttolomondo ME, Ben Altabef A, Mitzel NW (2016) Structure and bonding of 2,2,2-trichloroethylacetate: An experimental gas phase and computational study. ZNaturforsch(B) 71 (12):1253-1260

525 CAS RN: 1247981-86-7 MGD RN: 368444 GED augmented by DFT computations

(2Z)-3-Hydroxy-2-butenoyl fluoride Acetoacetyl fluoride, enol form C4H5FO2 Cs OH

Bonds C(1)–C(2) C(2)=C(3) C(3)–C(4) C(3)–O(2) C(1)=O(1) C(1)–F C(4)–H(3) C(4)–H(4) C(4)–H(5) O(2)–H(2) C(2)–H(1) O(1)..O(2) O(1)..H(2)

rh1[Å] a,b 1.436(4) 1 1.369(4) 1 1.495(4) 1 1.336(8) 1.208(5) 1.347(5) 1.081(6) 2 1.086(6) 2 1.086(6) 2 0.982(6) 2 1.071(6) 2 2.616(10) c 1.773(12) c

Bond angles C(3)=C(2)–C(1) C(2)–C(1)=O(1) C(2)=C(3)–O(2) O(1)=C(1)–F O(2)–C(3)–C(4) C(2)=C(3)–C(4) C(2)–C(1)–F C(3)–O(2)–H(2) O(2)–H(2)…O(1) H(3)–C(4)–C(3) H(4)–C(4)–C(3) H(5)–C(4)–C(3) H(4)–C(4)–H(3)

θh1 [deg] b,d 120.5(13) 126.2(15) 121.6(10) 119.4(10) 115.1(17) 123.3(16) c 114.3(15) c 107.7 e 146.1(20) c 112.8(13) 110.9(13) 3 110.9(13) 3 109.4 e

H3C

O

F

432

H(5)–C(4)–H(3)

6 Molecules with Four Carbon Atoms

109.4 e

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the value from B3LYP/cc-pVTZ computation. c Dependent parameter. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Adopted from computation as indicated above. The GED experiment was carried out at room temperature. The experimental intensities were reproduced reasonably well by the model of enol tautomer only. The diketo tautomer was not detected. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Belova NV, Oberhammer H, Zeng XQ, Gerken M, Willner H, Berger RJF, Hayes SA, Mitzel NW (2010) The keto/enol tautomerism in acetoacetyl fluoride: properties, spectroscopy, and gas-phase and crystal structures of the enol form. Phys Chem Chem Phys 12 (37):11445-11453

526 CAS RN: MGD RN: 474660 MW supported by ab initio calculations

1,1-Difluoroethene – fluoroethene (1/1) Vinylidene fluoride – vinyl fluoride (1/1) C4H5F3 Cs

Distances C(2)…C(4) F(1)…H(2) F(2)…H(1)

r0 [Å] a 5.475(12) 2.463(16) b 2.496(9) b

Angles C(3)=C(4)…C(2) C(4)…C(2)=C(1) C(1)–F(1)…H(2) F(1)…H(2)–C(4) C(3)–F(2)…H(1) F(2)…H(1)–C(1)

θ0 [deg] a

H

F

H

F

H

F

H

H

85.0(5) 7.22(7) 121.8(3) b 150.8(11) b 128.5(5) b 143.0(2) b

Copyright 2017 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the binary complex of 1,1-difluoroethene with fluoroethene was recorded by a pulsed-jet chirped-pulse FTMW spectrometer in the frequency region between 6 and 19 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main and four 13C) assuming that the structural parameters of the monomer subunits were not changed upon complexation. The C=C bonds are roughly perpendicular to each other, forming the cross of a T-shaped carbon framework, similar to the lowest-energy structure predicted by MP2/6-311++G(2d,2p) calculations.

6 Molecules with Four Carbon Atoms

433

Dorris RE, Peebles SA, Peebles RA (2017) Rotational spectrum and structural analysis of CH⋅⋅⋅F interactions in the vinyl fluoride⋅⋅⋅1,1-difluoroethylene dimer. J Mol Spectrosc 335(5):74-79

527 CAS RN: 381-88-4 MGD RN: 214559 MW augmented by ab initio calculations

1,1,1-Trifluoro-2-butanone C4H5F3O Cs

O

F

a

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(2)=O(5) C(1)–F(6) C(1)–C(7) C(1)–F(8) C(4)–H C(3)–H

r0 [Å] 1.542(1) 1.509 b 1.524 b 1.212 b 1.326 b 1.347 b 1.347 b 1.092 b 1.097 b

rs [Å] 1.493(6) 1.517(4) 1.524(3)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(2)=O(5) C(2)–C(1)–F(6) C(2)–C(1)–F(7) C(3)–C(4)–H(1) C(3)–C(4)–H(3) C(2)–C(3)–H(4)

θ0 [deg] a

θs [deg] a

Dihedral angles F(7)–C(1)–C(2)=O(5) C(1)–C(2)–C(3)–C(4) O(5)=C(2)–C(3)–C(4) F(6)–C(1)–C(2)=O(5) C(2)–C(3)–C(4)–H(1) C(2)–C(3)–C(4)–H(3) C(1)–C(2)–C(3)–H(4)

τ0 [deg] a

τs [deg] a

116.1(2) 112.3 b 125.4 b 112.5 b 109.9 b 110.8 b 110.1 b 107.5 b

120.5(1) 180 b 0b 0b -59.8 b 180 b 56.7 b

CH3

a

F

F

118.6(6) 113.4(4)

Reprinted with permission. Copyright 2009 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed at the value from MP2/6-311++G(d,p) calculation.

The rotational spectra of 1,1,1-trifluoro-2-butanone were recorded by chirped-pulse and conventional BalleFlygare type FTMW spectrometers in the frequency region between 8 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main and four 13C); the remaining structural parameters were fixed at the ab initio values (see above). The rs structure was also obtained for the carbon skeleton.

434

6 Molecules with Four Carbon Atoms

Evangelisti L, Sedo G, van Wijngaarden J (2011) Rotational spectrum of 1,1,1-trifluoro-2-butanone using chirped-pulse Fourier transform microwave spectroscopy. J Phys Chem A 115(5):685-690

528 CAS RN: 406-90-6 MGD RN: 493901 MW supported by ab initio calculations

(2,2,2-Trifluoroethoxy)ethene 2,2,2-Trifluoroethyl vinyl ether C4H5F3O Cs F

F

CH2

O

Bonds C(1)=C(2) C(2)–O(3) O(3)–C(4) C(4)–C(5) C(5)–F(6) C(5)–F(7)

r0 [Å] a 1.343(5) 1.364(4) 1.419(5) 1.508(7) 1.343(12) 1.334(3)

rs [Å] a 1.335(5) 1.365(3) 1.432(8) 1.482(7)

Bond angles C(1)=C(2)–O(3) C(2)–O(3)–C(4) O(3)–C(4)–C(5) C(4)–C(5)–F(6) F(6)–C(5)–F(7)

θ0 [deg] a

θs [deg] a

Dihedral angles C(1)=C(2)–O(3)–C(4) C(2)–O(3)–C(4)–C(5)

τ0 [deg]

τs [deg]

127.2(3) 116.0(3) 106.8(4) 108.8(5) 107.4(4)

0 180

F

127.6(4) 117.1(5) 105.1(4)

0 180

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of 2,2,2-trifluoroethyl vinyl ether (fluoroxene) were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 18 GHz. Only one conformer was observed. The partial r0 and rs structures were determined from the ground-state rotational constants of six isotopic species (main, four 13C and 18O). Uriarte I, Écija P, Spada L, Zabalza E, Lesarri A, Basterretxea FJ, Fernández JA, Caminati W, Cocinero EJ (2016) Potential energy surface of fluoroxene: experiment and theory. Phys Chem Chem Phys 18(5):3966-3974

529 CAS RN: 383-64-2 MGD RN: 145410 GED augmented by QC computations

Bonds r1 b C–S

rh1 [Å] a anti-gauche anti-anti 1.3858(12) c 1.3858(12) c c 1.7930(14) 1.7930(14) c

Trifluoroethanethioic acid S-ethyl ester Trifluorothioacetic acid S-ethyl ester S-Ethyl trifluoroacetate C4H5F3OS C1 (anti-gauche) O Cs (anti-anti) F S F F

CH3

6 Molecules with Four Carbon Atoms

C–H C(2)=O(6) C(1)–F(4) C(1)–F(3) C(1)–F(5) C(7)–S C(7)–C(8) C(1)–C(2) C(2)–S Bond angles C–C–H H(3)–C(8)–H(5) H(3)–C(8)–H(4) C–S–C S–C–C(1) C–C–F F(3)–C(1)–F(4) F(5)–C(1)–F(4) C–C=O H(1)–C(7)–H(2) S–C–C(8) C–C–H(3) C–C–H(4) C–C–H(5) C(2)–S–C(7) C–C–F(4) C–C–F(3) C–C–F(5) S–C(7)–C(8) S–C(2)–C(1) Dihedral angles F(4)–C(1)–C(2)–S C(1)–C(2)–S–C(7) C(2)–S–C(7)–C(8) H(3)–C(8)–C(7)–S

435

1.096(6) c,d 1.216(3) e 1.341(4) e 1.336(2) e 1.344(2) e 1.826(3) e 1.532(5) e 1.546(3) e 1.761(3) e,f

1.096(6) c,d 1.216(3) e 1.341(4) e 1.340(2) e 1.827(3) e 1.533(5) e 1.546(3) e 1.759(3) e,f

θh1 [deg] a

anti-gauche 112.6(10) c,d 108.2(9) d 108.5(9) d 95.9(6) c,d 114.0(3) c,d 111.4(1) c 109.0(9) d 108.3(9) d 119.5(6) c,d 108.2(7) d 113.1(6) c 111.8(11) e,g 112.9(11) e,g 112.7(11) e,g 95.9(6) e 113.1(4) e,h 111.5(4) e,h 110.0(4) e,h 115.0(6) e,i 113.7(4) e,i

anti-gauche 4.1(41) 161.4(27) –78.0(22) –176.5(51)

anti-gauche

anti-anti 112.6(10) c,d 108.2(9) d 95.9(6) c,d 114.0(3) c,d 108.2(9) d 119.5(6) c,d 108.3(7) d 113.1(6) c 1.115(11) e,g 1.135(11) e,g 95.9(6) e 113.1(4) e,h 110.3(4) e,h 111.3(7) e,i 114.3(4) e,i

τh1 [deg] a

anti-anti

anti-anti 0.0 j 180.0 j 180.0 j 180.0 j

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value of the C–C, C=O and C–F bond lengths. Differences between these parameters were constrained to the value from MP2/6-311++G(d,p) computation. c Average value for both conformers. d Constrained to the value from computation at the level of theory as indicated above. e Dependent parameter. f Difference between the C–S bond lengths was constrained as above. g Differences between the C–C–H bond angles were constrained as above. h Differences between the C–C–F bond angles were constrained as above. i Difference between the S–C–C bond angles was constrained as above. j According to symmetry. b

According to predictions of ab initio and DFT computations, the title molecules exist as anti-gauche (C1 pointgroup symmetry) and anti-anti (Cs) conformers characterized by the synclinal and/or antiperiplanar C−S−C−C dihedral angles, although there are disagreements about which conformer is more stable.

436

6 Molecules with Four Carbon Atoms

The evidence for presence of both conformers was obtained also in the IR vibrational spectra. The GED experiment was carried out at room temperature (approximately 293 K). The best fit to experimental intensities was obtained for a mixture of 51(3) % anti-anti and 49(3) % anti-gauche conformers. Vibrational corrections to the experimental bond internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311++G(d,p) computation. Defonsi Lestard ME, Tuttolomondo ME, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2009) A conformational and vibrational study of CF3COSCH2CH3. J Chem Phys 131(21):214303/1-214303/12 doi:10.1063/1.3267633

530 CAS RN: 383-63-1 MGD RN: 397114 GED supported by IR and augmented by QC computations

2,2,2-Trifluoroacetic acid ethyl ester Ethyl trifluoroacetate C4H5F3O2 C1 (anti-gauche) Cs (anti-anti) O

Bonds b

r1 C–H C(2)=O(6) C(2)–O(8) C(1)–F(3) C(1)–F(4) C(1)–F(5) C(7)–O(8) C(7)–C(9) C(1)–C(2) Bond angles C–C–H H(1)–C(9)–H(2) H(1)–C(9)–H(3) C–O–C O–C–C(1) C–C–F F(3)–C(1)–F(4) F(3)–C(1)–F(5) C–C=O H–C(7)–H O–C–C(9) C–C–H(1) C–C–H(2) C–C–H(3) C(2)–O(8)–C(7) C–C–F(3) C–C–F(4) C–C–F(5) O(8)–C(7)–C(9) Dihedral angles F(3)–C(1)–C(2)–O(8)

rh1 [Å] a anti-gauche anti-anti 1.3848(9) 1.3848(9) 1.081(7) c,d 1.081(7) c,d e 1.213(3) 1.212(3) e e 1.330(4) 1.331(4) e e 1.338(5) 1.344(2) e e 1.342(2) 1.338(5) e 1.345(2) e 1.338(5) e e 1.456(4) 1.454(4) e e 1.512(5) 1.508(5) e e 1.546(4) 1.545(4) e

θh1 [deg] a

anti-gauche 111.0(12) c,d 108.5(11) d 108.5(11) d 114.9(11) c,f 110.1(7) c 110.9(2) c,f 108.6(10) d 108.4(10) d 124.6(7) c,d 109.7(8) d 106.9(5) c,d 110.1(13) e 111.0(13) e 111.6(13) e 115.1(7) e 111.3(5) e 111.4(5) e 110.5(5) e 109.3(6) e

anti-anti 111.0(12) c,d 108.9(11) d 108.9(11) d 114.9(11) c,f 110.1(7) c 110.9(2) c,f 109.9(7) d 109.9(7) d 124.6(7) c,d 108.5(8) d 106.9(5) c,d 110.1(13) e 111.5(13) e 111.5(13) e 114.6(7) e 110.5(3) e 111.0(5) e 111.0(5) e 104.4(6) e

τh1 [deg] a

anti-gauche 175.5(44)

anti-anti 180.0

F O F

CH3

F

anti-gauche

anti-anti

6 Molecules with Four Carbon Atoms

C(1)–C(2)–O(8)–C(7) C(2)–O(8)–C(7)–C(9) H(1)–C(9)–C(7)–O(8)

182.4(31) -98.7(31) -172.7(60)

437

180.0 180.0 180.0

Copyright © 2009 John Wiley & Sons, Ltd. Reproduced with permission [a].

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value of the C=O, C−O, C−C and C−F bond lengths. Differences between these parameters were restrained to the values from MP2/6-311++G(d,p) computation. c Average value for both conformers. d Restrained to the value from computation at the level of theory as indicated above. e Dependent parameter. f Parameter difference between the conformers was restrained to the value from computation as indicated above. b

Two conformers, anti-anti with two antiperiplanar C–C–O–C dihedral angles and anti-gauche with the antiperiplanar and anticlinal C–C–O–C torsional angles, were predicted for title compound by QC computations; the former conformer is being lower in energy than the latter by 2.8 kJ mol−1 (MP2/6311++G(d,p)). Analysis of IR vibrational spectra provided the evidence for presence of both conformers. The GED experiment was carried out at the nozzle temperature of approximately 293 K. The best fit to the experimental intensities was obtained with the ratio of the conformers anti-gauche : anti-anti = 44 : 56. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311++G(d,p) computation. a. Defonsi Lestard ME, Tuttolomondo ME, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2010) Experimental and theoretical structure and vibrational analysis of ethyl trifluoroacetate, CF3CO2CH2CH3. J Raman Spectrosc 41 (10):1357-1368 MW supported by DFT calculations

Cs (syn-anti) C1 (syn-gauche)

syn-anti r0 [Å] a 1.1952 1.3201 1.4452 1.5047 1.5486 1.3234

syn-gauche r0 [Å] a 1.1948 1.3185 1.4428 1.5130 1.5455 1.3215

Bond angles O(1)=C(2)–C(1) O(1)=C(2)–O(2) C(2)–O(2)–C(3) O(2)–C(3)–C(4)

θ0 [deg] a

θ0 [deg] a

Dihedral angles O(1)=C(2)–O(2)–C(3) C(2)–O(2)–C(3)–C(4)

τ0 [deg] a

Bonds C(2)=O(1) C(2)–O(2) O(2)–C(3) C(3)–C(4) C(1)–C(2) C(1)–F

123.01 127.31 115.86 107.80

0 180

122.85 127.78 116.51 110.89

τ0 [deg] a 0.79 85.58

Copyright 2017 with permission from Elsevier [b].

a

syn-anti

Uncertainties were not given in the original paper.

syn-gauche

438

6 Molecules with Four Carbon Atoms

The rotational spectrum of the title compound was investigated by pulsed-jet FTMW spectroscopy in the frequency region between 7.6 and 16.2 GHz. Two conformers, syn-anti and syn-gauche, both with the synperiplanar O(1)=C(2)–O(2)–C(3) chain and differing in the conformations of the C(2)-O(2)-C(3)-C(4) chain (antiperiplanar and synclinal, respectively) were observed. For each of these conformers, the r0 structure of the heavy-atom skeleton was determined from the ground-state rotational constants of seven isotopic species (main, two 18O and four 13C). b. Bohn RK, Montgomery JA, Michels HH, Acharte C (2017) Microwave spectroscopy and curious molecular dynamics of ethyl trifluoroacetate. J Mol Spectrosc 335(5):13-16

531 CAS RN: 2835-21-4 MGD RN: 359607 MW augmented by QC calculations

3-Isocyano-1-propene Allyl isocyanide C 4H 5N Cs (syn) H 2C

N C

a

Bonds C(1)≡N(2) N(2)–C(3) C(3)–C(4) C(4)=C(5)

r0 [Å] 1.179 1.418 1.501 1.331

Bond angles C(1)≡N(2)–C(3) N(2)–C(3)–C(4) C(3)–C(4)=C(5)

θ0 [deg] a

b b b b

180 111.08(45) 127.8(11)

rs [Å] 1.175(12) 1.441(11) 1.4789(36) 1.3290(60)

θs [deg] a

176.6(11) 113.31(71) 126.00(35)

© AAS. Reproduced with permission. Published 2013 October 22

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Constrained to the value from MP2/6-311++G(d,p) calculations.

The rotational spectra of the title compound were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 4 and 18 GHz and a millimeter- and submillimeter-wave absorption spectrometer in the range up to 905 GHz (at room temperature). Three stable conformers, syn and two gauche, characterized by synperiplanar and ±anticlinal N-C-C=C torsional angles, respectively, were predicted by MP2 calculations with different Dunning’s basis sets. The gauche conformers are predicted to be higher in energy than the syn one by 2 kJ mol-1 and are separated by a barrier height of ≈ 10 kJ mol-1. Both the syn and gauche conformers were observed in the spectra. The partial r0 structure of the most stable conformer was determined from the ground-state rotational constants of six isotopic species (main, four 13C and 15N); the bond lengths were constrained to the ab initio values (see above). The rs structure of the heavy-atom skeleton was also determined. Haykal I, Margulès L, Huet TR, Motyienko RA, Écija P, Cocinero EJ, Basterretxea F, Fernández JA, Castaño F, Lesarri A, Guillemin JC, Tercero B, Cernicharo J (2013) The cm-, mm-, and sub-mm-wave spectrum of allyl isocyanide and radioastronomical observations in Orion KL and the SgrB2 line surveys. Astrophys J 777(2):120/1-120/8

532

1H-Pyrrole

6 Molecules with Four Carbon Atoms

439

CAS RN: 109-97-7 MGD RN: 415960 MW augmented by ab initio calculations

C 4H 5N C2v

Bonds C(2)–N N–H C(2)=C(3) C(2)–H C(3)–C(4) C(3)–H

r (1) [Å] a m 1.3764(10) 0.9943(8) 1.3783(15) 1.0740(8) 1.430(3) 1.0747(9)

r e [Å] a 1.36940(17) 1.00086(14) 1.3723(2) 1.07532(13) 1.4231(4) 1.07527(16)

Bond angles C(5)–N–C(2) C(2)–N–H N–C(2)=C(3) N–C(2)–H C(3)=C(2)–H C(2)=C(3)–C(4) C(2)=C(3)–H C(4)–C(3)–H

θ (1) [deg] a m

θ see [deg] a

109.67(9) 125.16(5) 107.85(9) 121.5(5) 130.7(5) 107.32(7) 126.0(5) 126.6(5)

N H

se

109.809(16) 125.096(8) 107.762(15) 120.99(7) 131.25(7) 107.334(12) 125.94(6) 126.73(5)

Reprinted with permission. Copyright 2014 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit.

was determined from the previously published ground-state rotational The mass-dependent structure r (1) m se

constants. The semiexperimental equilibrium structure r e was obtained by taking into account rovibrational corrections calculated with the MP2_ae/cc-pwCVTZ harmonic and anharmonic (cubic) force fields. Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and sevenmembered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746

533 CAS RN: 4747-72-2 MGD RN: 111024 MW augmented by ab initio calculations

Isocyanatocyclopropane Cyclopropyl isocyanate C4H5NO Cs N

C

Bonds C(1)–C(2) C(2)–C(2) C(1)–N N=C(4) C(4)=O C(1)–H(1) C(2)–H

anti r0 [Å] a 1.509(3) 1.523(3) 1.412(3) 1.214(3) 1.163(3) 1.085(2) 1.083(2)

syn r0 [Å] a 1.509(3) 1.521(3) 1.411(3) 1.212(3) 1.164(3) 1.082(2) 1.084(2)

Bond angles

θ0 [deg] a

θ0 [deg] a

O

440

6 Molecules with Four Carbon Atoms

C(2)–C(1)–C(2) C(2)–C(1)–N C(1)–N=C(4) N=C(4)=O N–C(1)–H(1) C(2)–C(1)–H(1) C(2)–C(2)–H(2) C(2)–C(2)–H(3) C(1)–C(2)–H(2) C(1)–C(2)–H(3)

60.6(5) 116.7(5) 136.3(5) 172.2(5) 115.4(5) 117.9(5) 117.2(5) 118.5(5) 116.2(5) 117.6(5)

60.5(5) 120.1(5) 137.6(5) 173.0(5) 112.0(5) 117.7(5) 117.3(5) 118.4(5) 116.7(5) 117.8(5)

Dihedral angle C(4)=N–C(1)–C(2)

τ0 [deg] a

τ0 [deg] a

145.6(5)

324.4(5)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized estimated uncertainties in units of the last significant digit.

anti

syn

The r0 structure of each of two conformers, syn and anti, was determined by fitting the MP2_full/6-311++G(d,p) structure to the three experimental ground-state rotational constants. The anti conformer is more stable than the syn form (41(2)%), as detected in the IR spectra of gas and variabletemperature liquid xenon solutions of cyclopropyl isocyanate. Durig JR, Zhou SX, Guirgis GA, Wurrey CJ (2011) Conformational stability from variable-temperature infrared spectra of xenon solutions, r0 structural parameters, and ab initio calculations of cyclopropyl isocyanate. J Phys Chem A 115(11) 2297-2307.

534 CAS RN: 123-56-8 MGD RN: 154097 GED augmented by ab initio computations

Distances N–H C–H C=O N–C C(2)–C(3) C(3)–C(4) N...X c

re [Å] a 1.007(18) 1.086(7) 1.202(1) 1.376(2) 1.520(4) b 1.526(5) 2.189(5)

Bond angles

θe [deg] a

2,5-Pyrrolidinedione Succinimide C4H5NO2 C2v O

H N

O

6 Molecules with Four Carbon Atoms

C–N–C N–C–C C–C–C C–N–H N–C=O C–C=O C(2)–C(3)–H C(3)–C(4)–H H–C–H

116.5(4) b 106.3(3) b 105.5(2) b 121.8(2) 126.1(4) 127.6(2) b 109.7(14) 112.7(12) b 106.5(29) b

Dihedral angles H–C–C–N H–N–C=O

τe [deg] a

441

± 121.7(14) 0.0 d

Reprinted with permission. Copyright 2009 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Dependent parameter. c X is the middle point between the C(3) and C(4) atoms. d Adopted from MP2_full/6-311G(3df,2p) computation. b

According to results of computations at the MP2_full level of theory (with cc-pVTZ and 6-311G(3df,2p) basis sets), the title molecule has C2v symmetry. The GED experiment was carried out at Tnozzle = 392 K. In the GED analysis, the large-amplitude ring-twisting motion was described by the dynamic model with distribution of pseudo-conformers according to the following PEF: V(ϕ) = V0 + 0.5 ∑ Vk (1 − cos k ϕ) , where ϕ is the ring-twisting coordinate. k = 3 ,5

Very large relaxation effects particularly for the C(3)–C(4) bond and strong anharmonicity of PEF justified the application of the dynamic model. Modelling the ring-bending motion, i.e. out-of-plane motion of the N atom, by harmonic potential energy function was shown to be appropriate. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2_full/6-311G(3df,2p) scaled quadratic and cubic force fields taking into account non-linear kinematic effects. Vogt N, Khaikin LS, Grikina OE, Karasev NM, Vogt J, Vilkov LV (2009) Flexibility of the saturated fivemembered ring in 2,5-pyrrolidinedione (succinimide): Electron diffraction and quantum-chemical studies with use of vibrational spectroscopy data. J Phys Chem A 113 (5):931-937

535 CAS RN: 822-35-5 MGD RN: 623459 MW augmented by QC calculations Bonds C(1)=C(2) C(2)–C(3) C(3)–C(4) C(1)–H C(4)–H

Cyclobutene C 4H 6 C2v

r see [Å] a 1.3408(3) 1.5148(1) 1.5644(3) 1.0802(1) 1.0892(1)

442

Bond angles C(1)=C(2)–H C(1)=C(2)–C(3) C(3)–C(4)–H H–C(3)–H

6 Molecules with Four Carbon Atoms

θ see [deg] a 133.47(2) 94.23(1) 114.60(1) 109.19(1)

Copyright 2014 with permission from Elsevier [a]. a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see was determined from the previously determined ground-state rotational constants for five isotopic species [b] taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the B3LYP/6-311+(3df,2pd) harmonic and anharmonic (cubic) force fields. a. Vogt N, Demaison J, Rudolph HD (2014) Semiexperimental equilibrium structure of the oblate-top molecules dimethyl sulfoxide and cyclobutene. J Mol Spectrosc 297:11-15 b. Bak B, Led JJ, Nygaard L, Rastrup-Andersen J, Sørensen GO (1969) Microwave spectra of isotopic cyclobutenes. Molecular structure of cyclobutene. J Mol Struct 3:369-378

536 CAS RN: 6680-69-9 MGD RN: 215636 MW augmented by ab initio calculations

1,2-Dihydro-1,2-azaborine C4H6BN Cs BH

Bonds B–N B–C(3) N–C(6)

r0 [Å] a 1.45(3) 1.51(1) 1.37(3)

Bond angles B–C(3)=C(4) N–B–C(3) C(6)–N–B C(5)=C(6)–N

θ0 [deg] a

NH

119 115(3) 123(3) 120

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 2σ values.

The rotational spectra of 1,2-dihydro-1,2-azaborine were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 7 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main, 10 B and D) assuming the remaining structural parameters at the values from MP2/6-311+G(d,p) calculations. Daly AM, Tanjaroon C, Marwitz AJV, Liu SY, Kukolich SG (2010) Microwave spectrum, structural parameters, and quadrupole coupling for 1,2-dihydro-1,2-azaborine. J Amer Chem Soc 132(15):5501-5506

6 Molecules with Four Carbon Atoms

443

537 CAS RN: 1640384-50-4 MGD RN: 492873 MW augmented by ab initio calculations

1,1'-Oxybismethane – 1-chloro-1,2,2-trifluoroethene (1/1) Dimethyl ether – chlorotrifluoroethylene (1/1) C4H6ClF3O C1 Cl

F

F

F

O H 3C

CH3

a

Distance C(2)…O(7)

r0 [Å] 2.908

Angles O(7)…C(1)=C(2) X…O(7)…C(1) b O(7)…C(1)=C(2)–Cl(3)

θ0 [deg] a 103.5(1) 107.7(1) 87.2(1)

Reprinted with permission. Copyright 2016 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. X is a dummy atom along the bisector of the C–O–C angle.

The rotational spectra of the binary complex of dimethyl ether with chlorotrifluoroethylene were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial effective structure r0 was determined from the ground-state rotational constants of two Cl isotopic species; the remaining structural parameters were constrained to the values from MP2/aug-cc-pVDZ calculations. Spada L, Gou Q, Geboes Y, Herrebout WA, Melandri S, Caminati W (2016) Rotational study of dimethyl etherchlorotrifluoroethylene: lone pair⋅⋅⋅π interaction links the two subunits. J Phys Chem A 120(27):4939-4943

538

Propyne – difluoromethane (1/1)

Methylacetylene – difluoromethane (1/1)

CAS RN: 1841151-27-6

MGD RN: 402337 MW supported by ab initio calculations

C4H6F2

Cs

H

H

H

C

Distances C(1)…X b F(3)…H(1) X…H(4)

r0 [Å] a 3.511(2) 3.078(4) c 3.200(1) c

rs [Å] a 3.480(2)

Angles F(3)–C(1)…X C(1)…X…C(8)

θ0 [deg] a

θs [deg] a

87.20(4) 85.73(9)

H

C

H

H F

F

85.85(17)

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. X is the midpoint of the C≡C bond. c Dependent parameter. b

The rotational spectra of the binary complex of propyne with difluoromethane were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 6.5 and 19 GHz.

444

6 Molecules with Four Carbon Atoms

The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, D and four 13C) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The partial rs structure was also obtained. The complex is formed by two hydrogen bonds between the methyl group in the propyne subunit and fluorine. Furthermore, two hydrogen atoms in the difluoromethane subunit interact with the π-electron system of the triple bond. Ernst AA, Christenholz CL, Dhahir YJ, Peebles SA, Peebles RA (2015) Alkynes as CH/π acceptors: microwave spectra and structures of the CH2F2⋅⋅⋅propyne and CH2CIF⋅⋅⋅propyne dimers. J Phys Chem A 119(52):1299913008

539 CAS RN: MGD RN: 430545 MW supported by ab initio calculations

Acetic acid – difluoroacetic acid (1/1) C4H6F2O4 Cs (anti) C1 (gauche) O O

Distance

anti 4.69

Rcm b

r0 [Å] a

F OH

gauche 4.67

H 3C

OH F

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Uncertainty was not given in the original paper. Distance between the centers of mass of the monomer subunits.

anti

gauche

The rotational spectrum of the binary complex was recorded in the 6 -18.5 GHz frequency range by a pulsed-jet FTMW spectrometer. Two conformers, anti and gauche, with the antiperiplanar and synclinal H–C–C–O torsional angles in the difluoroacetic acid subunit, respectively, were identified. The partial r0 structure of each conformer was determined from the ground-state rotational constants of four isotopic species (main, two D and D2) assuming that the structural parameters of the monomer subunits were not changed upon complexation. The complex is formed in an eight-membered ring structure via by two hydrogen bonds. Both conformers exhibit splittings of the rotational transitions. The barriers to internal rotation of the methyl group of the acetic acid subunit were determined to be 99.8(3) cm-1 and 90.5(9) cm-1 for the anti and gauche conformer, respectively.The barrier to the tunnelling motion of the CHF2 group between its two equivalent positions was estimated to be 108(2) cm-1. Gou Q, Feng G, Evangelisti L, Caminati (2014) Conformational equilibria and large-amplitude motions in dimers of carboxylic acids: rotational spectrum of acetic acid-difluoroacetic acid. ChemPhysChem 15(14):29772984

540

2,4(1H,3H)-Pyrimidinedione – water (1/1)

6 Molecules with Four Carbon Atoms

445

CAS RN: 133745-89-8 MGD RN: 208565 MW

Uracil – water (1/1) C4H6N2O3 C1 O

Distances H(2)…O(1) O(2)…H(1)

r0 [Å] a 1.98(8) 1.91(8)

Angles H(2)–O(2)…H(1) O(1)…H(2)–O(2) C=O(1)…H(2) O(2)…H(1)–N H(3)–O(2)–H(2)…O(1)

θ0 [deg] a

O

HN

O

H

H

N H

84(2) 145(3) 107(3) 146 b 140

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. b Dependent parameter. The rotational spectrum of the binary complex of uracil with water was investigated by laser ablation molecularbeam FTMW spectroscopy in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 18O, 15N2, 15N2/18O, 15N2/D2 and two 15N2/D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. López JC, Alonso JL, Peña I, Vaquero V (2010) Hydrogen bonding and structure of uracil-water and thyminewater complexes. Phys Chem Chem Phys 12(42):14128-14134

541 CAS RN: 78-94-4 MGD RN: 709570 MW supported by QC calculations

Bonds C(1)–C(2) C(2)–C(3) C(3)=C(4) C(2)=O Bond angles C(1)–C(2)=O C(1)–C(2)–C(3) O–C(2)–C(3) C(2)–C(3)=C(4)

3-Buten-2-one Methyl vinyl ketone C4H6O Cs (ap) Cs (sp) O

rs [Å] a

ap 1.4774(2) 1.49249(8) 1.33945(4) 1.2411(1)

θs [deg] a

ap 122.56(2) 121.21(2) 116.23(1) 123.32(1)

Copyright 2011 with permission from Elsevier.

sp 1.5037(1) 1.4751(3) 1.3334(2)

sp 117.94(2) 121.96(3)

H 3C

CH2

446 a

6 Molecules with Four Carbon Atoms

Parenthesized uncertainties in units of the last significant digit are errors propagated from rotational constants.

ap

sp

The rotational spectrum of the main and title compound was recorded by a chirped-pulse FTMW spectrometer in the region 7.5 to 18.5 GHz. Two conformers, ap and sp, with antiperiplanar and synperiplanar C=C−C=O torsional angles, respectively, were identified. The partial rs structures of the ap and sp conformers were determined from the ground-state rotational constants of six (main, four 13C and 18O) and five (main and four 13C) isotopic species, respectively. The barrier to internal rotation of the methyl group was determined to be 433.8(1) and 376.6(2) cm-1 for the ap and sp conformers, respectively. Wilcox DS, Shirar AJ, Williams OL, Dian BC (2011) Additional conformer observed in the microwave spectrum of methyl vinyl ketone. Chem Phys Lett 508(1-3):10-16

542 CAS RN: 108-05-4 MGD RN: 208910 MW augmented by ab initio calculations

Acetic acid ethenyl ester Vinyl acetate C 4H 6O 2 Cs O

Bonds O(2)–C(1) O(2)–C(3) O(4)=C(1) C(1)–C(5) C(3)=C(6) C(3)–H(1) C(5)–H(2) C(5)–H(3) C(6)–H(5) C(6)–H(6)

r0 [Å] 1.370 b 1.383 b 1.208 b 1.501 b 1.334 b 1.083 b 1.088 b 1.092 b 1.082 b 1.083 b

Bond angles C(1)–O(2)–C(3) O(2)–C(1)=O(4) O(2)–C(1)–C(5) O(2)–C(3)=C(6) C(6)=C(3)–H(1) C(1)–C(5)–H(2) C(1)–C(5)–H(3) C(3)=C(6)–H(5) C(3)=C(6)–H(6)

θ0 [deg] a 116.4(1) 123.9 b 110.1(1) 119.7 b 125.1 b 109.4 b 109.6 b 119.0 b 121.5 b

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

H 3C

O

CH2

6 Molecules with Four Carbon Atoms b

447

Fixed at the value from MP2_full/6-311++G**calculations.

The rotational spectrum of title compound was recorded by a Stark-modulated free-jet millimeter-wave spectrometer in the spectral range between 61 and 77 GHz. Only one conformer, sp-ap, characterized by the synperiplanar O=C–O–C and antiperiplanar C–O–C=C torsional angles, was observed. The partial r0 structure was determined from the ground-state rotational constants of the parent isotopic species. The barrier to internal rotation of the methyl group was determined to be 1.855(1) kJ mol-1. Ab initio calculations predicted two further conformers, sp-sp and ap-ac (ac is abbreviation for anticlinal), with the energy difference of 12.7 and 27.7 kJ mol-1, respectively, relative to the sp-ap conformer. Velino B, Maris A, Melandri S, Caminati W (2009) Millimeter wave free-jet spectrum of vinyl acetate. J Mol Spectrosc 256(2):228-231

543 CAS RN: 1759-53-1 MGD RN: 644652 MW augmented by DFT calculations

Cyclopropanecarboxylic acid C 4H 6O 2 C1 O

Bonds C(1)–C(3) C(1)–C(6) C(1)–C(9) C(3)–C(6)

r0 [Å] a 1.548 1.521 1.467 1.497

Bond angles C(3)–C(1)–C(6) C(6)–C(3)–C(1) C(1)–C(6)–C(3) C(1)–C(9)–O(1) C(1)–C(9)–O(2)

θ0 [deg] a

Dihedral angles C(3)–C(1)–C(9)–O(1) C(6)–C(1)–C(9)–O(1)

τ0 [deg] a

OH

58 60 62 112 126

148 -146

Reprinted with permission. Copyright 2015 American Chemical Society. a

Uncertainties were not given in the original paper.

The rotational spectrum of the title compound was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 11 GHz. Only a low-energy conformer with an antiperiplanar H-C-C=O dihedral angle was observed, whereas the highenergy conformer with a synperiplanar H-C-C=O dihedral angle was detected at room temperature. The partial r0 structure of the antiperiplanar conformer was determined from the ground-state rotational constants of five isotopic species (main, three 13C and D); the values of remaining structural parameters were adopted from B3LYP/aug-cc-pVQZ calculation. Pejlovas AM, Lin W, Kukolich SG (2015) Microwave spectrum for a second higher energy conformer of cyclopropanecarboxylic acid and determination of the gas phase structure of the ground state. J Phys Chem A 119(39):10016-10021

448

6 Molecules with Four Carbon Atoms

544 CAS RN: 600-22-6 MGD RN: 379077 MW augmented by ab initio calculations

2-Oxopropanoic acid methyl ester Methyl pyruvate C 4H 6O 3 Cs O

H 3C

Distances C(1)–C(2) C(2)=O(3) C(2)–C(4) C(4)=O(5) C(4)–O(6) C(7)–O(6) C(1)–H(1) C(1)–H(2) C(1)–H(3) C(7)–H(4) C(7)–H(5) C(7)–H(6) C(4)…C(7)

r0 [Å] 1.5058 b 1.2150 b 1.5438 b 1.2155 b 1.3325 b 1.4388 b 1.0898 b 1.9036 b 1.9036 b 1.0876 b 1.0912 b 1.0912 b

rs [Å] 1.504

Angles O(5)=C(4)–C(2) O(3)–C(2)–C(1) C(4)–C(2)–C(1) O(6)–C(4)–C(2) C(7)–O(6)–C(4) H(1)–C(1)–C(2) H(2)–C(1)–C(2) H(3)–C(1)–C(2) H(4)–C(7)–O(6) H(5)–C(7)–O(6) H(6)–C(7)–O(6) C(7)…C(4)–C(2)

θ0 [deg] a

θs [deg] a

b

122.6 125.4 117.2 111.9 b 114.2 109.3 b 109.8 b 109.8 b 105.2 b 110.2 b 110.2 b

O

a

CH3

O

1.503

2.365

115.2

146.7

Reprinted with permission. Copyright 2013 American Chemical Society.

a b

Uncertainties were not given in the original paper. Fixed to the MP2/6-311++G** value.

The rotational spectra of methyl pyruvate were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main and four 13C). The partial rs structure was obtained for the carbon skeleton. The splitting of the rotational transitions into quintets was observed, and the barriers to internal rotation of the methyl groups about the C‒O and C‒C bonds were determined to be 4.883(8) kJ mol‒1 and 4.657(8) kJ mol‒1, respectively. Velino B, Favero LB, Ottaviani P, Maris A, Caminati W (2013) Rotational spectrum and internal dynamics of methyl pyruvate. J Phys Chem A 117(3):590-593

545

Acetic anhydride

6 Molecules with Four Carbon Atoms

449

CAS RN: 108-24-7 MGD RN: 462961 GED augmented by QC computations

C 4H 6O 3 C1 (sp-ac) C2 (sp-sp) O

Bonds C–C C=O C–O C–H C(1)–C(2) C(3)–C(4) C(1)=O(1) C(3)=O(3) C(1)–O(2) C(3)–O(2) Bond angles H(1)–C–C C–C=O C–C–O C–O–C O–C=O H(2)–C–H(1) H(6)–C–H(5) H(2)–C–C H(6)–C–C C–C=O(1) C–C=O(3) O–C=O(3) O–C=O(1) C(4)–C–O(2) C(2)–C–O(2) Dihedral angles O=C–C–H(1) O=C–C–H(2) O=C–C–H(6) C(2)–C–O–C C(4)–C–O–C O(3)=C–O–C O(1)=C–O–C O(3)=C(3)–C(4)…O(2) O(1)=C(1)–C(2)…O(2)

rh1 [Å] a sp-ac

sp-sp 1.485(3) 1.183(1) 1.387(2) 1.084(4) b,c

sp-sp 109.5(1) b 126.3(5) 111.2(5) 120.3(1) b 122.5(2) d

H 3C

CH3

θh1 [Å] a

sp-sp 5.7(20) b

sp-ac

122.4(2) b 110.5(1) b 109.9(1) b 109.4(1) d 107.7(1) d 125.4(5) d 124.7(5) d 116.8(2) d 123.3(2) d 118.4(5) d 111.3(5) d

τh1 [Å] a

-155.7(15) b 26.6(16) d 177.6(1) b

sp-sp

sp-ac -1.1(10) b 21.7(19) b 173.5(20) b -41.5(15) b 142.0(18) d -7.8(20) d 176.2(11) d -178.6(1) d

Parenthesized uncertainties in units of the last significant digit are 1σ values. Constrained to the value from M06-2X/6-311++G** computations. c Average value. d Dependent parameter as being constrained to the respective parameter of the sp-sp conformer. b

O

1.084(4) b,c 1.486(3) d 1.488(3) d 1.190(1) d 1.182(1) d 1.365(2) d 1.400(2) d

Reprinted with permission. Copyright 2016 American Chemical Society [a].

a

O

sp-ac

450

6 Molecules with Four Carbon Atoms

The GED intensities, measured at an average temperature of 338 K [b], were reanalyzed. The model of two conformers, sp-sp and sp-ac, with the synclinal and/or synperiplanar O=C–O–C dihedral angles was used in the GED analysis. The amount of the sp-sp conformer was refined to be 40.7(94) %. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X/6-311++G** computation. The main discrepancies in the structures of the sp-ac conformer from previous [b] and this studies were observed for both O=C–O–C torsional angles (-27.4(3)° and 122.0(39)° from Ref. [b] vs. -7.8(20)° and 142.0(18)° in this study, respectively). a. Atkinson SJ, Noble-Eddy R, Masters SL (2016) Gas-phase structures of ketene and acetic acid from acetic anhydride using very-high-temperature gas electron diffraction. J Phys Chem A 120 (12):2041-2048 b. Wu G, Van Alsenoy C, Geise HJ, Sluyts E, Van der Veken BJ, Shishkov IF, Khristenko LV (2000) Acetic anhydride in the gas phase, studied by electron diffraction and infrared spectroscopy, supplemented with ab initio calculations of geometries and force fields. J Phys Chem A (2000) 104:1576-1587

546 CAS RN: 4538-50-5 MGD RN: 402130 MW augmented by ab initio calculations

2-Oxiranecarboxylic acid methyl ester Methyl glycidate C 4H 6O 3 C1 O

Distances C(2)–C(3) C(3)–C(7) C(7)…C(10) C(2)–O(1) C(3)–O(1) C(2)–H(4) C(2)–H(5) C(3)–H(6) C(7)=O(8) C(7)–O(9) C(10)–O(9) C(10)–H(1) C(10)–H(2) C(10)–H(3)

r0 [Å] a 1.4807 1.4961 2.3409 1.4300 b 1.4374 b 1.0847 b 1.0848 b 1.0847 b 1.2096 b 1.3344 b 1.4417 b 1.0892 b 1.0861 b 1.0890 b

rs [Å] a 1.5230 1.4543 2.3700

Angles C(2)–C(3)–C(7) C(2)–O(1)–C(3) H(4)–C(2)–O(1) H(5)–C(2)–O(1) H(6)–C(3)–O(1) C(7)–C(3)–O(1) O(8)=C(7)–C(3) O(9)–C(7)–C(3) C(10)–O(9)–C(7) H(1)–C(10)–O(9) H(2)–C(10)–O(9) H(3)–C(10)–O(9) C(3)–C(7)…C(10)

θ0 [deg] a

θs [deg] a

117.9 62.2 b 114.4 b 115.2 b 115.5 b 115.0 b 125.1 b 110.1 b 114.9 b 110.2 b 105.4 b 110.1 b 144.0

115.4

144.9

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Uncertainties were not given in the original paper.

O O

CH3

6 Molecules with Four Carbon Atoms b

451

Fixed to the value from MP2/6-311++G(2d,p) calculations.

The rotational spectra of the title compound were recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the frequency region between 6 and 16 GHz. Two lowest-energy conformers, anti and syn, characterized by the antiperiplanar and synperiplanar O(1)–C(3)– C(7)–O(9) torsional angles, respectively, were identified. For the anti conformer, the partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main and four 13C); the remaining structural parameters including dihedral angles were fixed to ab initio values (see above). The rs structure of the carbon skeleton was also determined. The barrier to internal rotation of the methyl group was determined to be V3 = 4.8672(95) kJ mol-1. Thomas J, Yiu J, Rebling J, Jäger W, Xu Y (2013) Chirped-pulse and cavity-based Fourier transform microwave spectroscopy of a chiral epoxy ester: methyl glycidate. J Phys Chem A 117(50):13249-13254

547 CAS RN: MGD RN: 213803 MW supported by ab initio calculations

2-Methyloxirane – carbon dioxide (1/1) Propylene oxide – carbon dioxide (1/1) C 4H 6O 3 C1 CH3 O

Distances O(1)…C(4) C(4)=O(2) C(4)=O(3)

rs [Å] a 2.800 1.167 1.153

Angles X…O(1)…C(4) b O(1)…C(4)=O(2) O(1)…C(4)=O(3) C(1)…X…O(1)…C(4) C(2)…X…O(1)…C(4) X…O(1)…C(4)=O(2) b X…O(1)…C(4)=O(3) b C(3)…C(2)…O(2)…O(3)

θs [deg] a

C

O

O

116.0 86.7 94.2 -89.9 90.1 5.9 -173.2 -66.0

Copyright 2011 with permission from Elsevier. a b

Uncertainties were not given in the original paper. X is the midpoint of the C(1)–C(2) bond.

The rotational spectrum of the binary complex was recorded in a supersonic jet by a pulsed-nozzle FTMW spectrometer in the spectral region between 5 and 24 GHz. The partial rs structure was determined from the experimental ground-state rotational constants of eight isotopic species (main, four 13C, two 18O and 18O2). The CO2 subunit and methyl group were found to be located on the opposite sides of the ring plane (anti conformer). The barrier height V3 to internal rotation of the CH3 group was determined to be 859.8(62) cm-1. According to MP2 calculations (with 6-311++G(d,p) and aug-cc-pVDZ basis sets), the anti conformer is more stable than the syn conformer (with CO2 and CH3 on the same side relative to the ring plane). Orita Y, Kawashima Y, Hirota E. (2011) Fourier transform microwave spectrum of the CO2-propylene oxide complex. J Mol Spectrosc 268(1-2):78-84

452

6 Molecules with Four Carbon Atoms

548 CAS RN: 110-15-6 MGD RN: 214688 GED augmented by ab initio computations

Bonds C(3)–C(2) C(2)–C(1) C(3)–C(4) C(1)–O(5) C(1)=O(6) C(4)–O(7) C(4)=O(8) C(3)–H(1) C(3)–H(2) C(2)–H(3) C(2)–H(4) O(5)–H(5) O(7)–H(6) Bonds C(3)–C(2) C(2)–C(1) C(3)–C(4) C(1)–O(5) C(1)=O(6) C(4)–O(7) C(4)=O(8) C(3)–H(1) C(3)–H(2) C(2)–H(3) C(2)–H(4) O(5)–H(5) O(7)–H(6) Bond angles C(3)–C(2)–C(1) C(2)–C(3)–C(4) C(2)–C(1)–O(5) O(5)–C(1)=O(6) C(3)–C(4)–O(7) O(7)–C(4)=O(8) C(2)–C(3)–H(1) C(2)–C(3)–H(2) C(3)–C(2)–H(3) C(3)–C(2)–H(4) C(1)–O(5)–H(5) C(4)–O(7)–H(6) Dihedral angles C(1)–C(2)–C(3)–C(4)

I (C2) 1.524(2) 1.509(2) 1.353(1) 1.207(1) 1.104 b 1.105 b 0.982 b

I (C2) 1.508(3) 1 1.499(2) 1 1.343(2) 2 1.202(1) 3 1.0870 d 1.0894 d 0.9671 d

ra [Å] a II (C2h) IV (C1) 1.524(2) 1.533(2) 1.507(2) 1.506(2) 1.510(2) 1.355(1) 1.358(1) 1.207(1) 1.206(1) 1.354(1) 1.206(1) 1.105 b 1.106 b 1.104 b 1.104 b 1.101 b 0.982 0.982 b 0.982 b re [Å] a,c II (C2h) IV (C1) 1.509(3) 1 1.518(3) 1 1 1.496(2) 1.496(2) 1 1.498(2) 1 2 1.345(2) 1.350(2) 2 3 1.203(1) 1.202(1) 3 1.345(2) 2 1.202(1) 3 d 1.0885 1.0893 d 1.0890 d 1.0878 d 1.0844 d d 0.9671 0.9672 d 0.9672 d

θe [deg] c,e

I (C2) II (C2h) 111.8(4) 4 112.3(4) 4

112.0(4) 5 111.7(4) 5 123.0(1) 6 122.7(1) 6 111.46 f 110.94 f

111.32 f

105.92 f

105.90 f

I (C2) 69.9(11)e

τe [deg] f

II (C2h) 180.00

Butanedioic acid Succinic acid C 4H 6O 4 C2 (I, aGa) C2h (II, aAa) C1 (III, sGa) C1 (IV, gAa) O OH HO O

I

II

IV (C1) 111.6(4) 4 112.0(4) 4 111.8(4) 5 122.5(1) 6 111.6(4) 5 123.0(1) 6 111.56 f 111.09 f 109.31 f 110.88 f 105.84 f 105.97 f IV

IV (C1) -177.98

6 Molecules with Four Carbon Atoms

C(3)–C(2)–C(1)–O(5) C(2)–C(3)–C(4)–O(7) C(4)…C(2)–C(3)–H(1) C(4)…C(2)–C(3)–H(2) C(1)…C(3)–C(2)–H(3) C(1)…C(3)–C(2)–H(4) O(6)=C(1)–O(5)–H(5) O(8)=C(4)–O(7)–H(6) C(2)…O(5)–C(1)=O(6) C(3)…O(7)–C(4)=O(8)

453

-169.42

180.00

-120.93 119.62

-121.33

-0.52

0.00

178.81

64.46 -175.10 -121.05 120.25 120.36 -120.22 -0.02 0.31 179.39 179.60

Copyright 2011 with permission from Elsevier [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 3σ and a systematic error of 0.001r. b Assumed at the calculated value, see re structure. c Parameters with equal superscripts were refined in one group; differences between parameters in each group were adopted from MP2/cc-pVQT computations. d Assumed at the value from computation as indicated above. e Parenthesized uncertainties in units of the last significant digit are 3σ values. f Assumed at the values from computation as indicated above. According to predictions of MP2/cc-pVTZ computations, three of seventeen predicted conformers are higher in energy than the lowest energy conformer by less than 2.2 kcal mol-1. Each of four lowest-energy conformers, IIV, are characterized by the antiperiplanar (A) or synclinal (denoted as G) C–C–C–C dihedral angle and by the two C–C–C–O chains in the antiperiplanar (a) and synperiplanar (s) or synclinal (g) configurations. They denoted as follows: aGa (I), aAa (II), sGa (III) and gAa (IV). All these conformers possess synperiplanar O=C– O–H chains. The GED experiment was carried out at Tnozzle ≈ 445 K. The best fit to the experimental intensities was obtained for the following ratio of the conformers: I : II : III : IV = 45(15) : 20(15) : 10(assumed) : 25(15) (in %). Thus, the ratio of the conformers with the synclinal and antiperiplanar C–C–C–C dihedral angles was refined to be G : A = 55(15) : 45(15) (%). Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2/cc-pVTZ quadratic and cubic force constants taking into account non-linear kinematic effects. a. Vogt N, Abaev MA, Rykov AN, Shishkov IF (2011) Determination of molecular structure of succinic acid in a very complex conformational landscape: Gas-phase electron diffraction (GED) and ab initio studies. J Mol Struct 996 (1-3):120-127 MW supported by QC calculations

C2

Bonds C(2)–C(3) C(3)–C(4) C(4)=O(8) C(4)–O(7) O(7)–H(6)

r0 [Å] a 1.5220(87) 1.5066(59) 1.2014(32) 1.3538(21) 0.9691(79)

rs [Å] a 1.4947(80) 1.4728(78) 1.2355(93) 1.3578(81) 0.953(13)

Bond angles C(1)–C(2)–C(3) C(2)–C(1)=O(6) O(6)–C(1)–O(5) C(1)–O(5)–H(5) C(2)–C(1)–O(2)

θ0 [deg] a

θs [deg] a

111.93(14) 125.38(30) 123.12(45) 106.04(74) 111.55(30)

112.52(69) 125.83(30) 120.27(72) 109.0(12) 113.8(10)

454

Dihedral angle C(1)–C(2)–C(3)–C(4) O(5)–C(1)–C(2)–C(3) H(5)–O(5)–C(1)–C(2)

6 Molecules with Four Carbon Atoms

τ0 [deg] a

-67.76(11) 169.34(27) 179.18(33)

τs [deg] a

-70.19(14) 169.2(11) 177.9(14)

Reproduced with permission from the PCCP Owner Societies [b].

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the most stable conformer of succinic acid were recorded in a supersonic jet by a BalleFlygare type FTMW spectrometer in the frequency region between 7 and 26 GHz and by a Stark-modulated millimeter-wave spectrometer in the frequency region between 48 and 70 GHz. The partial r0 and rs structure were determined for the most stable conformer from the ground-state rotational constants of six isotopic species (main, two 13C, two 18O and D). b. Jahn MK, Méndez E, Nair KPR, Godfrey PD, McNaughton D, Écija P, Basterretxea FJ, Cocinero EJ, Grabow JU (2015) Conformational steering in dicarboxy acids: the native structure of succinic acid. Phys Chem Chem Phys 17(30):19726-19734

549 CAS RN: 1422743-96-1 MGD RN: 376087 MW supported by ab initio calculations

2-Propenoic acid – formic acid (1/1) Acrylic acid – formic acid (1/1) C 4H 6O 4 Cs O H2C

s-cis

Distances C(1)…C(10) C(1)–C(2) C(2)–C(3) H(6)…O(11) H(7)…O(4) H(9)–C(10)

r0 [Å] a 3.806(1) 1.484 b 1.341 b 1.652 b 1.663 b 1.096 b

rs [Å] a 3.7937(1) 1.4936(1) 1.3321(2) 1.0874(1)

s-trans r0 [Å] a 3.805(1) 1.481 b 1.342 b 1.660 b 1.661 b 1.096 b

Angles O(11)=C(10)…C(1) C(10)…C(1)…C(3) C(1)=O(4)…H(7) C(10)–O(11)…H(6) O(4)…H(7)–O(8) O(11)…H(6)–O(5) C(1)–C(2)–C(3)

θ0 [deg] a

θs [deg] a

θ0 [deg] a

59.0(6) 153.9(2) 124.9 b 123.6 b 179.1 b 177.5 b 120.8 b

153.89(2)

120.53(2)

58.3(4) 154.6(2) 127.1 b 125.3 b 179.0 b 179.2 b 123.2 b

O

OH

H

OH

rs [Å] a 3.796(1) 1.490(1) 1.333(2) 1.0847(6)

θs [deg] a 155.3(2)

122.8(2)

Reproduced with permission from the PCCP Owner Societies. a b

Parenthesized uncertainties in units of the last significant digit. Dependent value.

The rotational spectra of the binary complex of acrylic acid with formic acid were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 18.5 GHz. Two conformers, scis and s-trans, were identified.

6 Molecules with Four Carbon Atoms

455

The partial r0 structures were determined from the ground-state rotational constants of five isotopic species (main, three D and D2). Moreover, the partial rs structures were obtained for the carbon skeleton.

s-cis

s-trans

Feng G, Gou Q, Evangelisti L, Xia Z, Caminati W (2013) Conformational equilibria in carboxylic acid bimolecules: a rotational study of acrylic acid-formic acid. Phys Chem Chem Phys 15(8):2917-2922

550 CAS RN: 4399-47-7 MGD RN: 185037 MW augmented by QC calculations

Bromocyclobutane Cyclobutyl bromide C4H7Br Cs (equatorial)

Bonds C(1)–Br C(1)–C(2) C(2)–C(3) C(1)–H C(2)–H(1) C(2)–H(2) C(3)–H(1) C(3)–H(2)

r0 [Å] a 1.942(3) 1.541(3) 1.552(3) 1.092(2) 1.093(2) 1.092(2) 1.091(2) 1.093(2)

Bond angles Br–C(1)–C(2) C(2)–C(1)–C(2') C(1)–C(2)–C(3) C(2)–C(3)–C(2') H–C(1)–C(2) H–C(1)–Br H(1)–C(2)–C(1) H(1)–C(2)–C(3) H(2)–C(2)–C(1) H(2)–C(2)–C(3) H(1)–C(2)–H(2) H(1)–C(3)–C(2) H(2)–C(3)–C(2) H(1)–C(3)–H(2)

θ0 [deg] a

Dihedral angle φb

118.4(5) 89.7(5) 86.8(5) 88.9(5) 111.8(5) 106.4(5) 110.4(5) 106.8(5) 117.9(5) 122.5(5) 110.1(5) 118.6(5) 109.7(5) 109.6(5)

τ0 [deg] a 29.8(5)

Copyright 2009 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Puckering angle defined as the angle between the C(3)–C(2)…C(2') and C(2)…C(2')–C(1) planes.

Br

456

6 Molecules with Four Carbon Atoms

Two conformers, equatorial and axial, were identified in the temperature-dependent IR and Raman vibrational spectra. The percentage of the axial conformer was estimated to be 20(1) % at ambient temperature. The r0 structure was determined for the most stable equatorial conformer by adjusting the MP2_full/6311+G(d,p) structure to the previously published experimental ground-state rotational constants of two isotopic species (main and 81Br). Durig JR, Klaassen JJ, Ganguly A, Gounev T, Groner P (2009) The r0 structural parameters, conformational stability, and vibrational assignment of equatorial and axial bromocyclobutane. J Mol Struct 934(1-3):66-78

551 CAS RN: 1120-57-6 MGD RN: 794875 MW augmented by QC calculations

Chlorocyclobutane Cyclobutyl chloride C4H7Cl Cs (axial) Cs (equatorial)

C(1)–Cl C(1)–C(4) C(4)–C(3) C(1)–H(3) C(4)–H(1) C(4)–H(2) C(3)–H(4) C(3)–H(5)

r0 [Å]a axial 1.803(5) 1.547(3) 1.557(3) 1.090(2) 1.091(2) 1.095(2) 1.091(2) 1.091(2)

Bond angles

θ0 [deg]a

Bonds

Cl–C(1)–C(4) C(4)–C(1)–C(2) C(3)–C(4)–C(1) C(4)–C(3)–C(2) H(3)–C(1)–C(4) H(3)–C(1)–Cl H(1)–C(4)–C(1) H(1)–C(4)–C(3) H(2)–C(4)–C(1) H(2)–C(4)–C(3) H(1)–C(4)–H(2) H(4)–C(3)–C(4) H(5)–C(3)–C(4) H(4)–C(3)–H(5) Dihedral angle φb

Cl

equatorial 1.783(5) 1.539(3) 1.558(3) 1.092(2) 1.093(2) 1.092(2) 1.091(2) 1.093(2) axial

axial 110.6(5) 88.9(5) 89.3(5) 88.1(5) 119.5(5) 106.9(5) 117.4(5) 122.4(5) 109.5(5) 106.3(5) 109.8(5) 108.4(5) 120.2(5) 109.6(5)

equatorial 118.1(5) 89.7(5) 86.9(5) 88.3(5) 111.6(5) 107.1(5) 110.1(5) 107.7(5) 118.1(5) 121.7(5) 110.1(5) 118.4(5) 110.2(5) 109.6(5)

τ0 [deg]a axial 22.3(5)

equatorial 30.7(5)

equatorial

Reproduced with permission of SNCSC

a b

Parenthesized estimated uncertainties in units of the last significant digit. Puckering angle defined as the angle between the C(4)–C(3)–C(2) and C(2)–C(1)–C(4) planes.

6 Molecules with Four Carbon Atoms

457

The axial and equatorial conformers were identified in the temperature-dependent IR vibrational spectra. The percentage of the axial conformer was estimated to be 15(1) % for ambient temperature. The r0 structural parameters of each conformer were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of two isotopic species. Durig JR, Klaassen JJ, Ganguly A, Gounev TK, Guirgis GA, Lin W (2008) The r0 structural parameters of equatorial and axial chlorocyclobutane, conformational stability from temperature dependent infrared spectra of xenon solutions, and vibrational assignments. Struct Chem 19(6):935-948

552 CAS RN: 666-16-0 MGD RN: 220112 MW augmented by QC calculations

Fluorocyclobutane Cyclobutyl fluoride C4H7F Cs F

equatorial r0 [Å] a 1.383(3) 1.543(3) 1.554(3) 1.094(3) 1.093(2) 1.091(2) 1.090(2) 1.093(2)

axial r0 [Å] a 1.407(3) 1.546(3) 1.554(3) 1.092(3) 1.092(2) 1.094(2) 1.091(2) 1.091(2)

Bond angles C(2)–C(1)–F C(2)–C(1)–C(2) C(3)–C(2)–C(1) C(2)–C(3)–C(2) H–C(1)–C(2) H–C(1)–F H(1)–C(2)–C(1) H(1)–C(2)–C(3) H(2)–C(2)–C(1) H(2)–C(2)–C(3) H(1)–C(2)–H(2) H(1)–C(3)–C(2) H(2)–C(3)–C(2) H(1)–C(3)–H(2)

θ0 [deg] a

θ0 [deg] a

Dihedral angle φb

τ0 [deg] a

Bonds C(1)–F C(1)–C(2) C(2)–C(3) C(1)–H C(2)–H(1) C(2)–H(2) C(3)–H(1) C(3)–H(2)

117.4(5) 89.3(5) 85.0(5) 88.6(5) 112.1(5) 107.7(5) 109.3(5) 112.8(5) 118.8(5) 118.5(5) 110.2(5) 116.4(5) 112.4(5) 109.4(5)

37.4(5)

109.2(5) 89.2(5) 89.2(5) 88.6(5) 120.4(5) 107.2(5) 116.3(5) 123.3(5) 110.4(5) 105.8(5) 109.9(5) 108.3(5) 120.1(5) 109.6(5)

equatorial

axial

τ0 [deg] a 20.7(5)

Copyright 2010 with permission from Elsevier. a b

Parenthesized estimated uncertainties in units of the last significant digit. Puckering angle defined as the angle between the C(3)–C(2)…C(2) and C(2)…C(2)–C(1) planes.

The r0 structures of the equatorial and axial conformers were determined from the previously published experimental ground-state rotational constants combined with structural parameters from MP2_full/6311+G(d,p) calculation.

458

6 Molecules with Four Carbon Atoms

The axial conformer was estimated to be present by temperature-dependent IR vibrational spectroscopy in amount of 8(1) % (at ambient temperature). Ganguly A, Klaassen JJ, Guirgis GA, Gounev TK, Durig JR (2011) Conformational stability, r0 structural parameters, and vibrational assignments of mono-substituted cyclobutanes: Fluorocyclobutane. Spectrochim Acta A 79(4):831-840

553 CAS RN: 598-45-8 MGD RN: 103282 MW augmented by QC calculations

2-Isocyanopropane Isopropyl isocyanide C 4H 7N Cs H 3C

N a

Bonds C(1)≡N(2) N(2)–C(3) C(3)–C(4) C(4)–H(1) C(4)–H(2) C(4)–H(3) C(3)–H(4)

r0 [Å] 1.176(3) 1.437(3) 1.525(5) 1.093(2) 1.093(2) 1.092(2) 1.095(2)

Bond angles C(1)≡N(2)–C(3) N(2)–C(3)–C(4) C(4)–C(3)–C(5) C(3)–C(4)–H(1) C(3)–C(4)–H(2) C(3)–C(4)–H(3) C(4)–C(3)–H(4) N(2)–C(3)–H(4) H(1)–C(4)–H(2) H(1)–C(4)–H(3) H(2)–C(4)–H(3)

θ0 [deg] a

Dihedral angles N(2)–C(3)–C(4)–C(5) C(1)≡N(2)–C(3)–C(4) N(2)–C(3)–C(4)–H(1) N(2)–C(3)–C(4)–H(2) N(2)–C(3)–C(4)–H(3)

C

H 3C

178.6(5) 109.4(5) 113.0(5) 109.6(5) 110.0(5) 110.8(5) 109.2(5) 106.5(5) 108.8(5) 108.9(5) 108.7(5)

τ0 [deg] a

122.1(5) -62.1(5) -178.1(5) 62.3(5) -57.9(5)

Copyright 2014 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last digit.

The r0 structural parameters were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of one isotopic species. Sawant DK, Klaassen JJ, Panikar SS, Durig JR (2014) Infrared and Raman spectra, adjusted r0 structural parameters, and vibrational assignment of isopropyl isocyanide. J Mol Struct 1073:112-118

6 Molecules with Four Carbon Atoms

554 CAS RN: 78-82-0 MGD RN: 497045 MW

Bonds C(1)–C(2) C(2)–C(4) C(4)≡N Bond angles C(2)–C(4)≡N C(1)–C(2)–C(1) C(1)–C(2)–C(4)

459

2-Methylpropanenitrile Isopropyl cyanide C 4H 7N Cs CH3

rs [Å] a 1.5362(56) 1.4613(63) 1.1573(62)

C

H3C

N

θs [deg] a

179.3(19) 111.87(48) 110.36(45)

© AAS. Reproduced with permission. Published 2017 December 8

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were studied by jet-cooled chirped-pulse FTMW spectroscopy in the frequency region between 6 and 18 GHz, by Stark-modulation spectroscopy in the region up to 75 GHz (at room temperature) and by frequency-modulation millimeter and submillimeter-wave absorption spectroscopy in the region up to 480 GHz. The rs structure of the heavy-atom skeleton was determined from the ground-state rotational constants of five isotopic species (main, three 13C and 15N). Kolesniková L, Alonso ER, Mata S, Cernicharo J, Alonso JL (2017) A comprehensive rotational study of interstellar isopropyl cyanide up to 480 GHz. Astrophys J Suppl Series 233(2):24/1-24/10 https://doi.org/10.3847/1538-4365/aa9614

555 CAS RN: 1795-48-8 MGD RN: 113750 MW augmented by QC calculations

2-Isocyanatopropane Isopropyl isocyanate C4H7NO Cs N

H 3C

Bonds C(4)–N(3) N(3)=C(2) C(2)=O C(4)–C(6) C(4)–H(5) C(6)–H(1) C(6)–H(8) C(6)–H(9)

r0 [Å] a 1.453(3) 1.208(5) 1.165(3) 1.524(3) 1.094(2) 1.095(2) 1.094(2) 1.092(2)

Bond angles N(3)=C(2)=O C(4)–N(3)=C(2)

θ0 [deg] a 172.6(5) 137.0(5)

C O CH3

460

6 Molecules with Four Carbon Atoms

N(3)–C(4)–C(6) C(6)–C(4)–C(7) N(3)–C(4)–H(5) C(6)–C(4)–H(5) C(4)–C(6)–H(8) C(4)–C(6)–H(9) C(4)–C(6)–H(1)

109.4(5) 113.1(5) 105.7(5) 109.4(5) 110.1(5) 110.7(5) 110.1(5)

Dihedral angle C(2)=N(3)–C(4)–H(5)

τ0 [deg] 180

Copyright 2015 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the most stable conformer, anti, characterized by the antiperiplanar C=N–C–H torsional angle, was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 11 and 21 GHz. The r0 structure of this conformer was determined by adjusting the MP2_full/6-311+G(d,p) structure to the ground-state rotational constants of one isotopic species. Two conformers, anti and gauche, were predicted by several QC calculations; the gauche conformer is higher in energy by 1.04 kJ mol-1 (MP2_full/cc-pVQZ). Both conformers were also identified in the temperature-dependent IR and Raman vibrational spectra; the enthalpy difference was determined to be 1.38(13) cm-1. Durig JR, Deodhar BS, Zhou SX, Herrebout W, Dom JJJ, van der Veken BJ, Gounev TK (2015) Raman, infrared and microwave spectra, r0 structural parameters, and conformational stability of isopropyl isocyanate. J Mol Struct 1099:163-173

556 CAS RN: 28051-68-5 MGD RN: 542790 MW supported by QC calculations

(E)-2-Methyl-2-propenal oxime (E)-Methacrylaldehyde oxime C4H7NO Cs OH

N

Bonds C(2)–C(3) C(2)–C(4)

r0 [Å] a 1.461(2) 1.502(2)

Bond angles C(4)–C(2)–C(3) H–C(3)–C(2) C(2)–C(3)=N

θ0 [deg] a

H 2C

H CH3

117.9(2) 117.9(2) 119.6(2)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ value.

The rotational spectra of the title molecule were investigated by conventional Stark-modulation MW spectroscopy in the frequency region between 8 and 40 GHz. Only the s-trans conformer characterized by the antiperiplanar C(1)=C(2)–C(3)=N torsional angle was observed.

6 Molecules with Four Carbon Atoms

461

The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D). Kuze N, Ohashi O, Sakaizumi T (2017) Microwave spectrum, molecular structure, dipole moment, and quantum chemical calculations of s-trans-(E)-2-methyl-2-propenal oxime. J Mol Spectrosc 337(1):17-26

557

(Isocyanatosilyl)cyclopropane Cyclopropylisocyanatosilane

CAS RN: 1824696-89-0

MGD RN: 469083 MW supported by ab initio calculations

C4H7NOSi

Cs (syn) C1 (gauche)

syn rs [Å] a 1.9072(73) 1.464(22) 1.464(22) 1.4944(33)

gauche rs [Å] a 1.816(27) 1.545(29) 1.542(26) 1.461(17)

Bond angles C(2)−C(9)−C(10) C(9)−C(2)−C(10) C(9)−C(10)−C(2) Si(3)−C(2)−C(9)

θs [deg] a

θs [deg] a

Dihedral angle H(1)−C(2)−Si(3)−N(4)

τs [deg] a

Bonds C(2)−Si(3) C(2)−C(9) C(2)−C(10) C(9)−C(10)

61.5(12) 57.1(12) 61.5(12) 119.4(12)

C N

61.8(16) 56.5(13) 61.7(12) 117.8(21)

179(3)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

O

H2 Si

gauche

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of cyclopropyl(isocyanato)silane was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial rs structures were determined for the syn and gauche conformers with the synperiplanar and anticlinal X…C(2)‒Si‒N angles, respectively (X is a point on the bisector of the C(10)‒C(2)‒C(9) angle), from the ground-state rotational constants of six and seven isotopic species (main, 29Si, 30Si, three or four 13C), respectively.

syn

Guirgis GA, Askarian SM, Morris T, Palmer MH, Pate BH, Seifert NA (2015) Molecular structure of cyclopropyl(isocyanato)silane: a combined microwave spectral and theoretical study. J Phys Chem A 119(49):11875-11881

558 CAS RN: 1638434-80-6 MGD RN: 426612 MW augmented by

1-Cyclopropylsilanecarbonitrile Cyclopropylcyanosilane C4H7NSi Cs (gauche)

462

6 Molecules with Four Carbon Atoms

QC calculations

C1 (anti) N

Bonds Si(1)−C(2) C(2)−C(4) C(2)−C(5) C(4)−C(5) Si(1)−C(3) C(3)≡N C(2)−H(3) C(4)−H(6) C(4)−H(7) C(5)−H(4) C(5)−H(5) Si(1)−H(1) Si(1)−H(2)

r0 [Å] anti 1.841(3) 1.518(3) 1.518(3) 1.494(3) 1.857(3) 1.160(3) 1.087(2) 1.085(2) 1.083(2) 1.085(2) 1.083(2) 1.478(3) 1.478(3)

Bond angles

θ0 [deg] a

Si(1)−C(2)−H(3) C(2)−C(4)−C(5) C(2)−C(5)−C(4) C(4)−C(2)−C(5) Si(1)−C(2)−C(4) Si(1)−C(2)−C(5) C(2)−Si(1)−C(3) Si(1)−C(3)≡N H(6)−C(4)−H(7) H(4)−C(5)−H(5) C(2)−Si(1)−H(1) C(2)−Si(1)−H(2) C(3)−Si(1)−H(1) C(3)−Si(1)−H(2) H(1)−Si(1)−H(2)

anti 115.8(5) 60.5(5) 60.5(5) 58.9(5) 120.5(5) 120.5(5) 106.6(5) 177.3(5) 115.1(5) 115.1(5) 113.5(5) 113.4(5) 106.4(5) 106.4(5) 109.9(5)

Dihedral angles

τ0 [deg] a

H(3)−C(2)−Si(1)−C(3) N≡C(3)−Si(1)−C(2)

C

a

anti 180.0(5) 0.0(5)

Si H2

gauche 1.844(3) 1.517(3) 1.522(3) 1.500(3) 1.840(3) 1.160(3) 1.087(2) 1.085(2) 1.083(2) 1.085(2) 1.083(2) 1.479(3) 1.478(3)

gauche 116.9(5) 60.6(5) 60.2(5) 59.1(5) 119.1(5) 118.8(5) 110.7(5) 178.2(5) 114.8(5) 114.8(5) 113.8(5) 109.6(5) 105.5(5) 105.9(5) 110.8(5)

gauche 66.0(5) 3.5(5)

Copyright 2014 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

anti

gauche

6 Molecules with Four Carbon Atoms

463

The existence of two conformers, anti and gauche, characterized by the antiperiplanar and synclinal H(3)−C(2)−S−C(3) torsional angles, was predicted by MP2_full and B3LYP calculations (with various basis sets (from 6-31G(d) to aug-cc-pVTZ). The anti conformer is the lowest energy conformer according to MP2 calculations, whereas the B3LYP method predicts the gauche conformer to be the most stable one. The rotational spectrum of the title compound was recorded by a pulsed-nozzle chirped-pulse FTMW spectrometer in the spectral range between 6 and 19.8 GHz. Both conformers were detected. The r0 structures were determined from the ground-state rotational constants of seven and eight isotopic species (main, 29Si, 30Si, 15N and three or four 13C accordingly) for the anti and gauche conformers, respectively, combined with the structural parameters predicted by MP2_full/6-311+G(d,p). Durig JR, Guirgis GA, Sawant DK, Seifert NA, Deodhar BS, Pate BH, Panikar SS, Groner P, Overby JS, Askarian SM (2014) Microwave, r0 structural parameters, conformational stability and vibrational assignment of cyclopropylcyanosilane. Chem Phys 445:68-81

559 CAS RN: 16482-32-9 MGD RN: 329873 IR

Distance Rcm b

r0 [Å] a 3.867

Ethene dimer Ethylene dimer C 4H 8 D2d H

H

H

H

2

Reproduced with permission from the PCCP Owner Societies.

a b

Uncertainty was not given in the original paper. Distance between centers of mass of both monomer subunits.

The rotationally resolved IR spectrum of the perdeuterated ethylene dimer was recorded in a supersonic jet by a tunable quantum cascade laser spectrometer in the region of ν11 fundamental band region of C2D4 at about 2200 cm-1. The partial r0 structure was determined from the resulting ground-state rotational constants under the assumption that the structural parameters of the monomer subunit were not changed upon complexation. The dimer forms a cross-shaped structure. Rezaei M, Michaelian KH, McKellar ARW, Moazzen-Ahmadi N (2012) Infrared spectra of ethylene clusters: (C2D4)2 and (C2D4)3. Phys Chem Chem Phys 14(23):8415-8418

560 CAS RN: 2406-33-9 MGD RN: 189269 GED augmented by QC computations

1,1-Dichloro-1-silacyclopentane C4H8Cl2Si C1 (see comment) Cl

Si

Bonds Si–C(2) Si–C(5) Si–Cl(6) Si–Cl(7) C(2)–C(3) C(4)–C(5) C(3)–C(4)

ra [Å] a 1.864(4) 1.871(4) 2.046(2) 2.048(2) 1.548(4) 1.552(4) 1.542(4)

Cl

464

6 Molecules with Four Carbon Atoms

C–H

1.103(7) b

Bond angles C–Si–C Cl–Si–Cl

θa [deg] a

Other angle

τa [deg] a

ϕ

c

97.4(6) 104.8(10)

74.8(58)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and the error propagated from the estimated uncertainties of the fixed parameters. b Average values. c Effective phase angle. The puckering amplitude for the five-membered ring was determined to be q = 0.480(24) Å. B3LYP and MP2 computations with different basis sets (up to 6-311++G(2df,2pd) and aug-cc-pVTZ) predicted the existence of two conformers with C2 and Cs point-group symmetry, respectively; the latter conformer is essentially less stable (by 3.5-5.0 kcal mol−1). The pseudorotation model of C2 symmetry did not lead to satisfactory fitting. The best fit to the experimental data was obtained for the model of a single conformer with C1 symmetry describing pseudorotation by the phase angle ϕ as adjustable parameter. The GED experiment was carried out at Tnozzle of 333 and 360 K at the two nozzle-to-plate distances. Dakkouri M, Typke V (2010) The molecular structure of 1,1-dichlorosilacyclopentane as obtained from gasphase electron diffraction and ab initio calculations. J Mol Struct 978 (1-3):48-60

561 CAS RN: MGD RN: 545846 MW augmented by ab initio calculations

1,1-Difluoroethane dimer C4H8F4 C1

F

Distances C(3)…C(2) H(5)...F(9) H(6)...F(10) F(7)...H(8) Rcm c C(1)–C(2) C(3)–C(4)

r0 [Å] a 3.749(2) 2.664(2) b 2.572(2) b 2.586(2) b 4.004

rs [Å] a 3.732(5)

Angles C(3)…C(2)–C(1) C(4)–C(3)…C(2)

θ0 [deg] a

θs [deg] a

Dihedral angles C(3)…C(2)–C(1)–H(3) C(1)–C(2)…C(3)–C(4)

τ0 [deg] a

τs [deg]

89.0(4) 161.8(2)

124.6(4) -145.1(3)

1.47(5) 1.50(1)

90(1) 164(2)

H 3C

F

2

6 Molecules with Four Carbon Atoms

465

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c Distance between centers of mass of two monomer subunits. b

The rotational spectra of the binary complex of the 1,1-difluoroethane dimer were recorded in a supersonic jet by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 2 and 20 GHz. Two forms were identified. The partial r0 structure of the most stable form was determined from the ground-state rotational constants of five isotopic species (main and four 13C); the remaining structural parameters were constrained to the values from MP2/6-311++G(d,p) calculations. A partial rs structure was also obtained for the carbon skeleton. Chen J, Zheng Y, Wang J, Feng G, Xia Z, Gou Q (2017) Weak hydrogen bond topology in 1,1-difluoroethane dimer: A rotational study. J Chem Phys 147(9):094301/1-094301/6 [http://dx.doi.org/10.1063/1.4994865]

562 CAS RN: MGD RN: 332632 MW augmented by ab initio calculations

Tetrahydrofuran – krypton (1/1) C4H8KrO C1 Kr

Distance Rcm b

r0 [Å] a 3.843(1)

Angles

θ0 [deg] a

c

φ θd

O

29(4) 24.1(1)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Distance between Kr and the center-of-mass of the tetrahydrofuran subunit. c Angle between the c principal axis and the projection of Rcm onto the bc plane. d Angle between the a principal axis and Rcm. b

The rotational spectrum of the binary van der Waals complex was recorded in a pulsed jet by a Balle-Flygaretype FTMW spectrometer in the frequency range between 6.5 and 18 GHz. The doublet splittings of rotational transitions reflected the residual pseudorotational effects of the ring in the complex. From the splitting between the two vibrational sublevels, the barrier to inversion was estimated to be 67 cm-1. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 86Kr); the remaining structural parameters were fixed to the values from MP2/6-311++G(d,p) calculations. The Kr atom was found to be located nearly above the O atom and almost perpendicular to the C-O-C plane. Gou Q, Feng G, Evangelisti L, Maris A, Marchini M, Velino B, Caminati W (2012) Rotational spectrum and internal dynamics of tetrahydrofuran-krypton. ChemPhysChem 13(1):221-225

466

6 Molecules with Four Carbon Atoms

563 CAS RN: 123-72-8 MGD RN: 223396 MW augmented by DFT calculations

Butanal n-Butylaldehyde C4H8O Cs (syn-anti) C1 (syn-gauche) O

Bonds C(1)−C(2) C(2)−C(3) C(3)−C(4) Bond angles C(1)−C(2)−C(3) C(2)−C(3)−C(4)

syn-anti rs [Å] a 1.58(1) 1.48(1) 1.531(5)

syn-gauche rs [Å] a 1.52(2) 1.51(3) 1.524(8)

θs [deg] a

θs [deg] a

112.4(6) 110(1)

H 3C

H

114.4(7) 113.2(7)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

syn-anti

syn-gauche

The rotational spectrum of the title compound was recorded by a chirped-pulse FTMW spectrometer in the region between 7.5 and 18.5 GHz. In addition to the previously observed syn-anti and syn-gauche conformers with the synperiplanar O=C(1)–C(2)–C(3) torsional angle and differing by the antiperiplanar and synclinal C(1)–C(2)–C(3)–C(4) torsional angles, respectively, a new conformer, gauche-gauche with the synclinal O=C(1)–C(2)–C(3) and C(1)–C(2)–C(3)–C(4) torsional angles, was also observed. According to prediction of B3LYP/6-311++G(d,p) calculations, the syn-anti and syn-gauche conformers are the lowest energy conformers with the first one being most stable. The partial rs structure of each of these two conformers, syn-anti and syn-gauche, was determined from the ground-state rotational constants of five isotopic species (main and four singly substituted 13C). Hotopp KM, Vaquero Vara V, Dian BC (2012) Conformational analysis of n-butanal by chirped-pulse Fourier transform microwave spectroscopy. J Mol Spectrosc 280:104-109

564 CAS RN: 2919-23-5 MGD RN: 426243 MW augmented by QC calculations

Bonds C(1)–O

Cyclobutanol Cyclobutyl alcohol C4H8O Cs (equatorial-anti)

r0 [Å] a 1.412 (3)

rs [Å] a 1.410 (4)

6 Molecules with Four Carbon Atoms

467

C(1)–C(4) C(4)–C(6) O–H(7) C(1)–H(3) C(4)–H(8) C(4)–H(9) C(6)–H(1) C(6)–H(2)

1.547(3) 1.556(3) 0.961(3) 1.093(2) 1.096(2) 1.092(2) 1.091(2) 1.093(2)

1.547 (3) 1.554 (2) 0.956 (6)

Bond angles O–C(1)–C(4) C(4)–C(1)–C(5) C(6)–C(4)–C(1) C(4)–C(6)–C(5) C(1)–O–H(7) H(3)–C(1)–C(4) H(3)–C(1)–O H(8)–C(4)–C(1) H(8)–C(4)–C(6) H(9)–C(4)–C(1) H(9)–C(4)–C(6) H(8)–C(4)–H(9) H(1)–C(6)–C(4) H(2)–C(6)–C(4) H(1)–C(6)–H(2)

θ0 [deg] a

θs [deg] a

Dihedral angles H(7)–O–C(1)–H(3) C(6)–C(5)–C(4)–C(1)

τ0 [deg] a

τs [deg] a

120.2(5) 88.9(5) 87.1(5) 88.3(5) 107.8(5) 110.4(5) 105.9(5) 109.8(5) 107.9(5) 118.8(5) 121.4(5) 109.6(5) 118.6(5) 110.0(5) 109.3(5)

OH

119.5 (4) 88.8 (1) 87.6 (2) 88.3 (1) 108.3 (6)

180.0(10) 148.7(10)

150.2 (8)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 25 GHz. Only the equatorial-anti conformer, characterized by equatorial position of the OH group with respect to the ring and by the antiperiplanar H(7)–O–C(1)–H(3) torsional angle, was observed. The r0 structure was determined by adjusting the MP2_full/6-311+G(d,p) structure to the ground-state rotational constants of six isotopic species (main, three 13C, 18O and D). The rs parameters were determined for the heavy-atom skeleton. Lin W, Ganguly A, Minei AJ, Lindeke GL, Pringle WC, Novick SE, Durig JR (2009) Microwave spectra and structural parameters of equatorial-trans cyclobutanol. J Mol Struct. 922(1-3):83-87

565 CAS RN: MGD RN: 460482 MW supported by ab initio calculations

Distances Rcm b

r0 [Å] a 3.518

Oxirane – thiirane (1/1) Ethylene oxide – ethylene sulfide (1/1) C4H8OS Cs

rs [Å] a

468

6 Molecules with Four Carbon Atoms

C–S c C–C c C–C d

1.817 1.475 1.461

Bond angle C–S–C c

θs [deg] a

O

S

47.9

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Uncertainties were not given in the original paper. Distance between centers of mass of the monomer subunits. c Thiirane subunit. d Oxirane subunit. b

The rotational spectrum of the binary complex of oxirane with thiirane was recorded by a pulsed-jet BalleFlygare type FTMW spectrometer in the frequency region between 4 and 24 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 34 S and two 13C) under the assumption that the structural parameters were not changed upon complexation. The partial rs structure was also obtained. Kawashima Y, Tatamitani Y, Mase T, Hirota E (2015) Dimethyl sulfide-dimethyl ether and ethylene oxideethylene sulfide complexes investigated by Fourier transform microwave spectroscopy and ab initio calculation. J Phys Chem A 119(42) 10602-10612

566 CAS RN: 123-91-1 MGD RN: 482056 Ra augmented by ab initio calculations

1,4-Dioxane p-Dioxane C 4H 8O 2 C2h O

Bonds C–C C–O C–H(1) C–H(2)

r see [Å] a 1.5135(3) 1.4168(4) 1.0885(1) 1.0963(1)

Bond angles C–O–C C–C–H(2) H–C–H

θ see [deg] a

Dihedral angle

τ see [deg] a

θb

110.1(1) 109.481(7) 109.123(5)

52.299(6)

Reproduced with permission of AIP Publishing [a].

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Flap angle between the C–O–C and C–C–C–C planes.

O

6 Molecules with Four Carbon Atoms

469

The rotationally resolved femtosecond time-resolved Raman coherence spectra of 1,4-dioxane and its perdeuterated species were recorded in a supersonic jet. From the resulting ground-state rotational constants a The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants taking into account rovibrational corrections calculated with the CCSD(T)/cc-pCVDZ quadratic and cubic force fields. a. Den T, Menzi S, Frey HM, Leutwyler S (2017) Accurate gas-phase structure of para-dioxane by fs Raman rotational coherence spectroscopy and ab initio calculations. J Chem Phys 147(7):074306/1-074306/15 [http://dx.doi.org/10.1063/1.4997633] C2h

GED augmented by QC computations

Bonds C–H(1) b C–H(2) b C–O C–C

rα [Å] a 1.082(4) 1.090(4) 1.417(2) 1.510(4)

Bond angles C–O–C C–C–O C–C–H(1) b C–C–H(2) b H–C–H

θα [deg] a

Dihedral angle

θα [deg] a

ϕ

c

rg [Å] a 1.099(4) 1.108(4) 1.420(2) 1.514(4)

110.9(10) 111.1(3) 106.9(55) 104.6(55) 108.0(26)

50.6(7)

Copyright 2014 with permission from Elsevier [b].

a

Parenthesized uncertainties in units of the last significant digit are 2.5σ values. H(1) and H(2) are equatorial and axial H atoms, respectively. c Flap angle by which the COC plane is tilted up from the plane of the four carbon atoms. b

The GED experiment was carried out at Tnozzle = 294 K. The title compound was found to exist as a single conformer with a chair conformation of the ring. Vibrational corrections to the experimental internuclear distances, ∆rα = ra − rα, were calculated with harmonic force constants from B3LYP/cc-pVTZ computation. b. Fargher M, Hedberg L, Hedberg K (2014) The molecular structure of gaseous 1,4-dioxane: An electrondiffraction reinvestigation aided by theoretical calculations. J Mol Struct 1071:41-44

567 CAS RN: 856297-46-6 MGD RN: 212173 MW augmented by ab initio calculations

2,3-Butanedione – water (1/1) Diacetyl – water (1/1) C 4H 8O 3 O Cs CH3

H 3C

Distances

r0 [Å] a

O

O H

H

470

6 Molecules with Four Carbon Atoms

C(1)–C(2) C(1)=O(3) C(1)–C(9) C(2)=O(4) C(2)–C(5) C(5)–H(8) C(5)–H(6) C(9)–H(1) C(9)–H(2) O(8)–H(4) O(8)–H(5) H(4)…O(4) H(8)…O(8)

1.541 b 1.220 b 1.501 b 1.225 b 1.496 b 1.083 b 1.088 b 1.083 b 1.088 b 0.966 b 0.958 b 1.981(4) 2.56(1)

Angles C(2)–C(1)=O(3) C(1)–C(2)=O(4) C(1)–C(2)–C(5) C(2)–C(1)–C(9) C(2)–C(5)–H(8) C(2)–C(5)–H(6) C(1)–C(9)–H(1) C(1)–C(9)–H(2) H(4)–O(8)–H(5) H(4)…O(4)=C(2) O(8)–H(4)…O(4)

θ0 [deg] a

Dihedral angles H(8)–C(2)–C(5)–H(6) H(1)–C(1)–C(9)–H(2)

τ0 [deg]

119.0 b 118.7 b 117.0 b 116.7 b 110.4 b 109.3 b 109.5 b 109.8 b 105.1 b 115.2 b 166.3(4)

122.0 121.6

b b

Reprinted with permission. Copyright 2009 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. Constrained to the value from MP2/6-311++G(2d,2p) calculations.

The rotational spectrum of the binary complex of diacetyl with water was recorded in a supersonic jet by a BalleFlygare type FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from three ground-state rotational constants. From the analysis of the observed splittings, the barriers to internal rotation of the C(9)H3 and C(5)H3 groups were determined to be 3.81(2) and 4.11(2) kJ mol‒1, respectively. Favero LB, Caminati W (2009) Hydrated complexes of atmospheric interest: rotational spectrum of diacetylwater. J Phys Chem A 113(52):14308-14311 568 CAS RN: MGD RN: 483839 MW supported by ab initio calculations

2-Hydroxyacetaldehyde dimer Glycolaldehyde dimer C 4H 8O 4 C2 O

HO H

Distances C(1)–C(2)

rs [Å]a 1.515(12)

2

6 Molecules with Four Carbon Atoms

C(1)–O(1) C(2)=O(2) O(1)...O(2ꞌ)

1.371(16) 1.217(2) 2.869(3)

Angles C(2)–C(1)–O(1) C(1)–C(2)–O(2) C(1)–O(1)…O(2ꞌ) C(2)=O(2)…O(1ꞌ)

θs [deg]a

Dihedral angles O(1)–C(1)–C(2)=O(2) C(2)=O(2)…O(1ꞌ)–C(1ꞌ) O(1)…O(2ꞌ)=C(2ꞌ)–C(1ꞌ)

τs [deg]a

471

115.42(31) 123.94(46) 89.79(50) 125.51(15)

3.96(104) 107.30(24) 13.72(61)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are propagated from the standard deviations in the rotational constants.

The rotational spectra of the dimer were recorded in the 2 - 8 GHz frequency range using a broadband chirpedpulse FTMW spectrometer. Two conformers were identified. In the most stable conformer with C2 symmetry, the monomer subunits are held together by two intermolecular O–H…O=C hydrogen bonds, whereas in the less stable conformer, the O(2) atom is involved into one intermolecular and one intramolecular O(1)–H…O(2) hydrogen bond. According to MP2/aug-cc-pVTZ calculations, the second conformer is higher in energy by 5 kJ mol-1. The partial rs structure of the most stable conformer was determined from the experimental ground-state rotational constants of five isotopic species (main, two 13C and two 18O). Zinn S, Medcraft C, Betz T, Schnell M (2016) High-resolution rotational spectroscopy study of the smallest sugar dimer: Interplay of hydrogen bonds in the glycolaldehyde dimer. Angew Chem 128(20):6079-6084; Angew Chem Int Ed 55(20):5975-5980

569 CAS RN: 1357167-41-9 MGD RN: 333026 MW augmented by ab initio calculations

1-Fluoro-1-silacyclopentane C4H9FSi C1 SiH

Bonds Si(1)–C(2) Si(1)–C(3) C(2)–C(4) C(3)–C(5) C(4)–C(5) Si(1)–F(6) Si(1)–H(1) C(2)–H(2) C(3)–H(3) C(2)–H(4) C(3)–H(5) C(5)–H(6) C(4)–H(7)

r0 [Å] a 1.875(3) 1.872(3) 1.549(3) 1.547(3) 1.542(3) 1.598(3) 1.479(2) 1.097(2) 1.097(2) 1.093(2) 1.093(2) 1.097(2) 1.097(2)

rs [Å] b 1.875 1.841 1.535 1.570 1.568

F

472

6 Molecules with Four Carbon Atoms

C(5)–H(8) C(4)–H(9)

1.094(2) 1.094(2)

Bond angles C(3)–Si(1)–C(2) Si(1)–C(2)–C(4) Si(1)–C(3)–C(5) C(2)–C(4)–C(5) C(3)–C(5)–C(4) F(6)–Si(1)–H(1) H(2)–C(2)–H(4) H(3)–C(3)–H(5) H(7)–C(4)–H(9) H(6)–C(5)–H(8) F(6)–Si(1)–C(2) F(6)–Si(1)–C(3) H(1)–Si(1)–C(3) H(1)–Si(1)–C(2) H(2)–C(2)–Si(1) H(3)–C(3)–Si(1) H(4)–C(2)–Si(1) H(5)–C(3)–Si(1) H(2)–C(2)–C(4) H(3)–C(3)–C(5) H(4)–C(2)–C(4) H(5)–C(3)–C(5) H(6)–C(5)–C(4) H(7)–C(4)–C(5) H(8)–C(5)–C(4) H(9)–C(4)–C(5) H(6)–C(5)–C(3) H(7)–C(4)–C(2) H(8)–C(5)–C(3) H(9)–C(4)–C(2)

θ0 [deg] a

Dihedral angles Si(1)–C(2)–C(4)–C(5) C(2)–C(4)–C(5)–C(3)

τ0 [deg] a

θs [deg] b

96.7(5) 103.6(5) 102.9(5) 108.4(5) 108.1(5) 105.2(5) 107.3(5) 107.4(5) 107.1(5) 107.2(5) 110.7(5) 111.6(5) 116.1(5) 116.5(5) 108.5(5) 109.8(5) 115.3(5) 114.4(5) 109.7(5) 109.4(5) 112.4(5) 112.9(5) 108.7(5) 108.5(5) 111.2(5) 111.5(5) 109.5(5) 109.6(5) 112.0(5) 111.8(5)

-34.3(4) 49.9(5)

97.6 104.1 102.8 107.6 107.5

b

τs [deg] b -34.2 49.4

Reproduced with permission of AIP Publishing.

a b

Parenthesized estimated uncertainties in units of the last significant digit. Uncertainties were not given in the original paper.

The rotational spectra of 1-fluorosilacyclopentane were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. IR and Raman vibrational spectra indicated the presence of a single conformer with a twisted configuration. The r0 structure was determined by utilizing the ground-state rotational constants of seven isotopic species (main, 29Si, 30Si and four 13C) combined with the MP2_full/6-311+G(d,p) structure. The rs structure was obtained for the ring-skeleton. Durig JR, Panikar SS, Obenchain DA, Bills BJ, Lohan PM, Peebles RA, Peebles SA, Groner P, Guirgis GA, Johnston MD (2012) Microwave, infrared and Raman spectra, r0 structural parameters, ab initio calculations and vibrational assignment of 1-fluoro-1-silacyclopentane. J Chem Phys 136(4):044306/1-044306/10 [doi:10.1063/1.3673889]

6 Molecules with Four Carbon Atoms

570 CAS RN: 4909-00-6 MGD RN: 745893 MW

473

N,N-Dimethylmethanamine – trifluoroiodomethane (1/1) Trimethylamine – trifluoroiodomethane (1/1) C4H9F3IN C3v CH3

a

Distances Rcm b N…I

r0 [Å] 4.080(2) 2.781(2)

Angles

θ0 [deg] a

c

α γd

F

F

N H 3C

F

CH3

I

16.2(20) 4.12(37)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Distance between centers of mass of the monomer subunits. c Angular oscillation of the amine subunit. d Angular oscillation of the trifluoroiodomethane subunit. b

The rotational spectra of the binary complex of trimethylamine with trifluoroiodomethane were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.7 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 15N) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Stephens SL, Walker NR, Legon AC (2011) Internal rotation and halogen bonds in CF3I⋅⋅⋅NH3 and CF3I⋅⋅⋅N(CH3)3 probed by broadband rotational spectroscopy. Phys Chem Chem Phys 13(46):20736-20744

571 CAS RN: 27607-77-8 MGD RN: 372814 GED augmented by QC computations

1,1,1-Trifluoromethanesulfonic acid trimethylsilyl ester Trimethylsilyl trifluoromethylsulfonate C4H9F3O3SSi C1 O F

Bonds r1 b r2 c C–H S=O(2) S=O(3) S–O(4) C(1)–F(5) C(1)–F(6) C(1)–F(7) Si–O(4) Si–C(8) Si–C(9) Si–C(10) S–C(1)

rh1 [Å] a 1.3956(12) 1.8390(14) 1.094(6) d 1.423(3) e 1.419(3) e 1.544(3) e 1.330(5) e 1.329(4) e 1.329(4) e 1.747(5) e 1.865(5) e 1.867(6) e 1.865(5) e 1.851(4) e

CH3

O S

Si O

F F

CH3 CH3

474

6 Molecules with Four Carbon Atoms

Bond angles Si–C–H O–Si–C O(4)–Si–C(8) O(4)–Si–C(9) O(4)–Si–C(10) C(8)–Si–C(9) C(9)–Si–C(10) O–S=O O(2)=S=O(3) O–S–C C(1)–S=O(2) C(1)–S=O(3) S–O–Si S–C–F S–C(1)–F(5) S–C(1)–F(6) S–C(1)–F(7) F(5)–C–F(7) F(6)–C–F(7)

θh1 [deg] a

Dihedral angles C(9)–Si–O(4)–S F(7)–C(1)–S–O(4) C(1)–S–O(4)–Si

τh1 [deg] a

111.2(11) d,f 106.8(8) d 109.5(9) e,g 102.5(7) e,g 108.2(9) e,g 112.5(10) 112.3(10) 110.2(4) d 121.7(6) e 100.6(16) 106.5(14) 105.2(12) 129.7(7) 109.5(3) d 109.8(4) e,h 110.2(4) e,h 108.7(4) e,h 110.0(9) f 109.0(9) f

176.5(28) -174(23) 119.2(44)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Average value of the S=O, S−O and C−F bond lengths. Differences between these parameters were restrained to the values from MP2/6-311G(3df,3pd) computation. c Average value of the Si−C, Si−O and S−C bond lengths. Differences between these parameters were restrained to the values from computation as indicated above. d Average value. e Dependent parameter. f Restrained to the value from computation as indicated above. g Differences between the O–Si–C angles were restrained to the values from computation as indicated above. h Differences between the S–C–F angles were restrained to the values from computation as indicated above. b

Only one stable conformation characterized by the anticlinal C(1)–S–O(4)–Si torsional angle was predicted by B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) computations. The stabilization of this structure with respect to the antiperiplanar conformer was explained mainly by hyperconjugative interaction of the electron lone pair on O(4) and σ*[C(1)–S] (nonbonding σ orbital of the C–S bond), lp[O(4)] -> σ*[C(1)–S]. The GED experiment was carried out at the nozzle temperature of approximately 293 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311++G(d,p) computation. Defonsi Lestard ME, Tuttolomondo ME, Varetti EL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2010) Investigation of the gas-phase structure and rotational barrier of trimethylsilyl trifluoromethanesulfonate and comparison with covalent sulfonates. J Mol Struct 984 (1-3):376-382

572 CAS RN: 513-48-4 MGD RN: 495250

2-Iodobutane sec-Butyl iodide C4H9I

6 Molecules with Four Carbon Atoms

475

MW augmented by ab initio calculations

I

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(2)–I

r0 [Å] a 1.536(12) 1.497(6) 1.548(6) 2.166(4)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4)

θ0 [deg] a

Dihedral angles C(1)–C(2)–C(3)–C(4) I–C(2)–C(3)–C(4)

τ0 [deg] a

H 3C

C1 CH3

112.9(10) 114.17(23)

172.7(16) -63.85(31)

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of 2-iodobutane were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5.5 and 16.5 GHz. Three conformers were observed, one anti and two gauche conformers. The partial r0 structure was determined for the gauche-conformer from the ground-state rotational constants of five isotopic species (main and four 13C); the remaining structural parameters were fixed at the values of MP2/6311++G(2d,2p) calculations. The dihedral angle indicates a non-planar carbon chain. Arsenault EA, Obenchain DA, Choi YJ, Blake TA, Cooke SA, Novick SE (2016) A study of 2-iodobutane by rotational spectroscopy. J Phys Chem A 120(36):7145-7151

573 CAS RN: 2516-34-9 MGD RN: 295331 MW augmented by QC calculations

Aminocyclobutane Cyclobutylamine C 4H 9N C1 NH2

Bonds C(1)–N(2) C(1)–C(4) C(1)–C(5) C(4)–C(6) C(5)–C(6) N(2)–H(1) N(2)–H(2) C(1)–H(3) C(4)–H(4) C(4)–H(5) C(5)–H(6) C(5)–H(7) C(6)–H(8)

r0 [Å] a 1.453(5) 1.560(5) 1.547(5) 1.557(5) 1.555(5) 1.016(2) 1.015(2) 1.096(2) 1.093(2) 1.096(2) 1.092(2) 1.096(2) 1.092(2)

476

6 Molecules with Four Carbon Atoms

C(6)–H(9)

1.093(2)

Bond angles N(2)–C(1)–C(4) N(2)–C(1)–C(5) C(4)–C(1)–C(5) C(6)–C(4)–C(1) C(6)–C(5)–C(1) C(4)–C(6)–C(5) C(1)–N(2)–H(1) C(1)–N(2)–H(2) H(1)–N(2)–H(2) H(3)–C(1)–C(4) H(3)–C(1)–C(5) H(3)–C(1)–N(2) H(4)–C(4)–C(1) H(4)–C(4)–C(6) H(5)–C(4)–C(1) H(5)–C(4)–C(6) H(4)–C(4)–H(5) H(6)–C(5)–C(1) H(6)–C(5)–C(6) H(7)–C(5)–C(1) H(7)–C(5)–C(6) H(6)–C(5)–H(7) H(8)–C(6)–C(4) H(8)–C(6)–C(5) H(9)–C(6)–C(4) H(9)–C(6)–C(5) H(8)–C(6)–H(9)

θ0 [deg] a

Dihedral angle φb

τ0 [deg] a

122.8(5) 116.8(5) 88.1(5) 86.9(5) 87.5(5) 87.9(5) 109.9(5) 111.0(5) 107.6(5) 108.5(5) 108.7(5) 109.5(5) 118.8(5) 119.6(5) 109.6(5) 110.3(5) 109.6(5) 118.4(5) 120.0(5) 109.5(5) 110.0(5) 109.4(5) 118.0(5) 118.1(5) 111.1(5) 111.8(5) 109.2(5)

22.9(5)

Copyright 2008 with permission from Elsevier.

a b

Parenthesized estimated uncertainties in units of the last significant digit. Puckering angle defined as the angle between the C(6)–C(5)…C(4) and C(5)…C(4)–C(1) planes.

According to the analysis of the temperature-dependent IR vibrational spectra, the equatorial-gauche conformer with the synclinal lp–N–C–H angle (lp is an electron lone pair of the N atom) is the most stable conformer of the title molecule. The enthalpy difference between this conformer and the next low-energy conformer, equatorialanti, was determined to be 2.69(31) kJ mol-1. The percentage of the equatorial-anti conformer was estimated to be only 13(1) % (at ambient temperature). The r0 structural parameters of the equatorial-gauche conformer were obtained by adjusting the MP2_full/6311+G(d,p) structure to the previously published experimental ground-state rotational constants of two isotopic species. Durig JR, Ganguly A, El Defrawy AM, Guirgis GA, Gounev TK, Herrebout WA, van der Veken BJ (2009) Conformational stability, r0 structural parameters, barriers to internal rotation and vibrational assignment of cyclobutylamine. J Mol Struct 918(1-3):64-76

574 CAS RN: 123-75-1

Pyrrolidine

6 Molecules with Four Carbon Atoms

477

C 4H 9N Cs (equatorial) C1 (twisted)

MGD RN: 347290 MW augmented by ab initio calculation

equatorial r0 [Å] a 1.469(3) 1.469(3) 1.541(3) 1.541(3) 1.556(3) 1.016(2) 1.104(2) 1.093(2) 1.104(2) 1.093(2) 1.092(2) 1.092(2) 1.092(2) 1.092(2)

twisted r0 [Å] a 1.476(3) 1.479(3) 1.556(3) 1.544(3) 1.543(3) 1.017(2) 1.093(2) 1.094(2) 1.093(2) 1.097(2) 1.095(2) 1.093(2) 1.093(2) 1.093(2)

Bond angles N(1)–C(2)–C(4) N(1)–C(3)–C(5) C(2)–C(4)–C(5) C(3)–C(5)–C(4) C(2)–N(1)–C(3) C(2)–N(1)–H(1) C(3)–N(1)–H(1) H(4)–C(2)–N(1) H(2)–C(2)–N(1) H(3)–C(3)–N(1) H(5)–C(3)–N(1) H(4)–C(2)–C(4) H(2)–C(2)–C(4) H(3)–C(3)–C(5) H(5)–C(3)–C(5) H(4)–C(2)–H(2) H(3)–C(3)–H(5) H(8)–C(5)–C(3) H(6)–C(5)–C(3) H(7)–C(4)–C(2) H(9)–C(4)–C(2) H(8)–C(5)–C(4) H(6)–C(5)–C(4) H(7)–C(4)–C(5) H(9)–C(4)–C(5) H(8)–C(5)–H(6) H(7)–C(4)–H(9)

θ0 [deg] a

θ0 [deg] a

Dihedral angles N(1)–C(2)–C(4)–C(5) N(1)–C(3)–C(5)–C(4) C(2)–C(4)–C(5)–C(3) C(2)–N(1)–C(3)–C(5) C(3)–N(1)–C(2)–C(4)

τ0 [deg] a

Bonds N(1)–C(2) N(1)–C(3) C(2)–C(4) C(3)–C(5) C(4)–C(5) N(1)–H(1) C(2)–H(4) C(2)–H(2) C(3)–H(3) C(3)–H(5) C(5)–H(8) C(5)–H(6) C(4)–H(7) C(4)–H(9)

102.5(5) 102.5(5) 104.3(5) 104.3(5) 104.1(5) 111.7(5) 111.7(5) 112.0(5) 111.1(5) 112.0(5) 111.1(5) 109.6(5) 113.1(5) 109.6(5) 113.1(5) 108.5(5) 108.5(5) 111.6(5) 110.1(5) 111.6(5) 110.1(5) 112.5(5) 110.4(5) 112.5(5) 110.4(5) 107.9(5) 107.9(5)

-27.0(5) 27.0(5) 0 -45.8(5) 45.8(5)

107.6(5) 105.4(5) 104.6(5) 103.7(5) 103.9(5) 108.4(5) 108.0(5) 110.0(5) 108.3(5) 110.7(5) 108.2(5) 113.0(5) 110.1(5) 113.9(5) 110.2(5) 107.7(5) 108.2(5) 109.0(5) 113.6(5) 112.0(5) 110.6(5) 110.0(5) 112.4(5) 111.6(5) 110.6(5) 108.1(5) 107.5(5)

τ0 [deg] a 10.0(5) -32.8(5) 13.5(5) 39.4(5) -30.6(5)

Reprinted with permission. Copyright 2011 American Chemical Society.

N H

equatorial

twisted

478 a

6 Molecules with Four Carbon Atoms

Parenthesized estimated uncertainties in units of the last significant digit.

The r0 structures of the equatorial and twisted conformers of pyrrolidine were determined by fitting the MP2_full/6-311++G(d,p) structures to the experimental ground-state rotational constants published elsewhere. The equatorial conformer is more stable than the twisted form (37(3)%), as determined from IR spectra of gas and variable-temperature liquid xenon solutions of pyrrolidine. Durig JR, El-Defrawy AM, Ganguly A, Panikar SS, Soliman MS (2011) Conformational stability from variabletemperature infrared spectra of xenon solutions, r0 structural parameters, and vibrational assignment of pyrrolidine. J Phys Chem A 115(26):7473-7483

575 CAS RN: 3268-79-9 MGD RN: 448106 GED augmented by ab initio computations

Bonds N=O S–N C–S C(1)–C(2) C(1)–C(3) C–H Bond angles O=N–S N–S–C S–C–C(2) S–C–C(3) C(1)–C–H C(2)–C(1)–C(3) C(2)–C(1)–C(4) Dihedral angle N–S–C–C(2)

Thionitrous acid S-(1,1-dimethylethyl) ester tert-Butyl thionitrite C4H9NOS Cs (syn) Cs (anti) H 3C

re [Å] a,b anti syn 1.195(5) 1 1.202(5) 1 2 1.770(2) 1.744(2) 2 2 1.828(2) 1.829(2) 2 1.520(2) 3 1.521(2) 3 3 1.522(2) 1.524(2) 3 4,c 1.103(5) 1.102(5) 4,c

θe [deg] a,b

anti 113.6(6) 5 97.6(14) 6 109.5(4) 7 102.2(8) 8 109.5(8) 9,c 114.3(12) d 107.0(19) d

H 3C

S

O

N CH3

anti

syn 117.3(6) 5 109.3(14) 6 109.9(4) 7 101.3(8) 8 109.5(8) 9,c 102.8(25) e 126.4(41) e

τe [deg] a anti syn 58.5(11) 71.7(29)

syn

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from MP2_full/cc-pVTZ calculation. c Average value. d Dependent parameter. e Probably dependent parameter. b

The GED experiment was carried out at Tnozzle of 273…276 K at the short and long nozzle-to-plate distances, respectively. Two conformers with the antiperiplanar and synperiplanar O=N–S–C dihedral angles were found

6 Molecules with Four Carbon Atoms

479

to be present in amounts of 79(8) and 21(8) %, respectively. The same ratio of the conformers was determined by matrix isolation (Ar) IR spectroscopy, being also in a good agreement with predictions of ab initio computation. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from the B3LYP/6-31G(d,p) quadratic and cubic force fields taking into account non-linear kinematic effects. Canneva A, Erben MF, Romano RM, Vishnevskiy YV, Reuter CG, Mitzel NW, Della Védova CO (2015) The structure and conformation of (CH3)3CSNO. Chem Eur J 21 (29):10436-10442

576 CAS RN: 594-70-7 MGD RN: 286395 GED supplemented by MW and augmented by QC computations

2-Methyl-2-nitropropane Trimethylnitromethane C4H9NO2 Cs H3C

O N

Bonds C–H N=O(1) N=O(2) C–N C(2)–C(3) C(1)–C(2)

re [Å] a,b 1.092 c,d 1.226(8) 1 1.226(8) 1 1.520(4) 2 1.515(4) 2 1.521(4) 2

Bond angles N–C–C(3) N–C(2)–C(1) C(1)–C(2)–C(4) C(3)–C(2)–C(1) O=N=O C–N=O(2) C–N=O(1) C–C–H

θe [deg] a,e

H 3C H3C

O

109.1(8) 3 106.1(8) 3 111.6(6) 3 111.8(6) 3 124.2(6) 4 116.6(6) 4 119.1(6) 4 110(3) b

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscript were refined in one group; differences between parameters in each group were assumed at the values from MP2/6-311G(d) computation. c Average value. d Assumed at the value from computation as above. e Parenthesized uncertainties in units of the last significant digit are 3σ values. Reinvestigation of molecular structure from Ref. [b]. The GED experiment was carried out at Tnozzle = 291 K. The large-amplitude motion of the nitro group was described by a model of pseudo-conformers taking into account relaxation effects according to QC computations. The GED data did not allow a reliable determination of the barrier to internal rotation of the nitro group. However, their analysis showed that the low barrier of 203(2) cal mol-1, determined by MW spectroscopy [c], must correspond to the equilibrium structure with the synperiplanar O(1)=N–C(2)–C(3) dihedral angle. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2/6311G(d) quadratic and cubic force constants taking into account non-linear kinematic effects.

480

6 Molecules with Four Carbon Atoms

a. Tarasov YI, Kochikov IV, Kovtun DM, Polenov EA, Ivanov AA (2017) Internal rotation and equilibrium structure of the 2-methyl-2-nitropropane molecule from joint processing of gas phase electron diffraction data, vibrational and microwave spectroscopy data, and quantum chemical calculation results. J Struct Chem (Engl Transl) / Zh Strukt Khim 58/58 (3/3):498-507/525-534 b. Shishkov IF, Sadova NI, Vilkov LV, Pankrushev YA (1983) Geometrical structure of dimethylnitromethane and trimethylnitromethane molecules in gaseous phase. J Struct Chem (Eng. Transl.) / Zh Strukt Khim 24/24 (2 /2): 25-30 /189-193 c. Langridge-Smith PRR, Stevens R, Cox AP (1980) Microwave spectrum and barrier to internal rotation of 2methyl-2.nitropropane, Me3CNO2. J Chem Soc Faraday Trans II 76:330-338

577 CAS RN: 16966-40-8 MGD RN: 518900 GED augmented by QC computations

Bonds C=Se N=C N–Si Si–C C–Hʹ C–Hʹʹ

re [Å] a 1.709(14) 1.190(10) 1.767(15) 1.847(13) 1.092 b 1.091 b

Bond angles N–Si–C C–Si–C Si–C–Hʹ Si–C–Hʹʹ Hʹʹ–C–Hʹʹ Hʹ–C–Hʹʹ

θe [deg]

Isoselenocynatotrimethylsilane C4H9NSeSi C3v

106.4 c 112.4 c 106.4 c 111.2 c 109.9 c 109.0 c

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Assumed at the value from B3LYP/aug-cc-pVTZ computation. c Assumed. b

The GED experiments were carried out at Tnozzle = 330 K. The C3v point-group symmetry was assumed. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from QC quadratic and cubic force constants taking into account non-linear kinematic effect. Khaikin LS, Grikina OE, Kochikov IV, Stepanov NF (2014) Quantum-chemical calculations for silyl- and alkylpseudohalides X3YNCZ (X = H or CH3; Y = C or Si; Z = O, S, or Se) and electron diffraction study of the equilibrium molecular structure of (CH3)3SiNCSe. Russ J Phys Chem A / Zh Fiz Khim 88 / 88 (4 / 4):657-660 / 643-646

578 CAS RN: 18983-86-3 MGD RN: 441744 GED augmented by ab initio computations

1-(Dimethylphosphino)ethanone Acetyldimethylphosphine C4H9OP C1

6 Molecules with Four Carbon Atoms

Bonds C–H C=O C–C P–C(3) P–C(4) P–C(1)

rh1 [Å] a 1.088(2) b 1.231(2) 1.512(3) 1.842(4) 1.854(4) 1.863(6)

Bond angles C(1)–P–C(3) C(1)–P–C(4) C(3)–P–C(4) P–C(1)=O P–C(1)–C(2) C(2)–C(1)=O

θh1 [deg] a

Dihedral angle βc

τh1 [deg]

481 CH3 P

CH3

H 3C O

98.4(2) 100.0(4) 102.7(12) 121.0(3) 117.8(2) 121.2(2)

75.1 d

Reproduced with permission of SNCSC[a]. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 1σ and a systematic error. b Average value. c Angle between the P–C(1) bond and the C(3)PC(4) plane. d Uncertainty was not stated. At the MP2_full/6-311G(3df,2p) level of theory, the barrier to the P-inversion was estimated to be 23 kcal mol−1, whereas the barriers to internal rotation around the P−C(1) bond were predicted to be only 2.7 and 5.4 kcal mol−1 for the transition states with the P(CH3)2 group in the synperiplanar and antiperiplanar positions relative to the carbonyl group, respectively. The GED data obtained at Tnozzle = 323…333 K in Ref. [b] were reanalyzed. The large-amplitude torsion of the acetyl group was described by the dynamic model governed by PEF from MP2_full/6-31G(d,p) computation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from computation at the level of theory as indicated above. a. Khaikin LS, Grikina OE, Stepanov NF (2010) A quantum-chemical and gas phase electron diffraction study of the structure of formylphosphine and acetyldimethylphosphine. Russ J Phys Chem A / Zh Fiz Khim 84 / 84 (10 / 10):1745-1751 / 1913-1919 b. Khaikin LS, Andrutskaya LG, Grikina OE, Vilkov LV, El’natanov YI, Kostyanovskii RG (1977) Molecular structure of acetyldimethylphosphine, MeC(O)PMe2. I. Gas phase electron diffraction study. J Mol Struct 37:237-250

579 CAS RN: 1719-53-5 MGD RN: 372992 GED augmented by ab initio computations

Dichlorodiethylsilane C4H10Cl2Si C1 (IV) H3C

Bonds

rh1 [Å] a

Cl

Cl Si

CH3

482

6 Molecules with Four Carbon Atoms

Si–Cl C–H C–C Si–C

2.0592(5) 1.097(2) b 1.536(2) 1.8570(14)

Bond angles Cl–Si–Cl Si–C–C Si–C–H C–C–H C–Si–C

θh1 [deg] a

Dihedral angle C–C–Si…X c,d

τh1 [deg] a

107.4(2) 115.2(2) 108.8(6) b 110.3(7) b 115.4(6)

-118.4(19) b

Copyright © 2009 John Wiley & Sons, Ltd. Reproduced with permission.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Restrained to the value from MP2/cc-pVTZ computation. c Dihedral angle of the anticlinal unit. d X is the bisector of the Cl–Si–Cl angle. b

The GED experiment was carried out at room temperature. The title compound was found to exist as a mixture of four conformers, characterized by different sets of two C– C–Si…X dihedral angles as follows: conformer I by two equal synperiplanar angles (C2v point-group symmetry), conformer II by two equal anticlinal angles with different signs (Cs), conformer III by two equal anticlinal angles C2 and conformer IV by one synclinal and the other synperiplanar angles (C1). The ratio of the conformers was determined to be I : II : III : IV = 24 : 22 : 14 : 40(4) (in %). Small differences between the related parameters of the conformers were assumed at the values from MP2/ccpVTZ computations. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from computation at the level of theory as indicated above. The structural parameters are presented for the major conformer (IV). The existence of more than one conformer was confirmed also by the analysis of IR spectra in the 700-300 cm−1 region. Montejo M, Wann DA, Rodríguez Ortega PG, Robertson HE, Márquez F, Rankin DWH, López Gonzáles JJ (2010) Conformational landscape of small organosilicon compounds from the combined use of gas electron diffraction, IR and Raman spectroscopies and quantum chemical calculations: diethyldichlorosilane. J Raman Spectrosc 41 (10):1323-1330

580 CAS RN: 1220105-48-5 MGD RN: 211115 MW augmented by QC calculations

Bonds Ge–C(2) C(2)–C(4) C(2)–C(5) C(4)–C(5) Ge–C(6)

Cyclopropylmethylgermane C4H10Ge C1 (gauche) H

r0 [Å] a 1.925(5) 1.517(3) 1.519(3) 1.502(3) 1.947(5)

H Ge CH3

6 Molecules with Four Carbon Atoms

C(2)–H C(4)–H(1) C(4)–H(2) C(5)–H(3) C(5)–H(4) Ge–H(5) Ge–H(6) C(6)–H(7) C(6)–H(8) C(6)–H(9)

1.087(2) 1.085(2) 1.084(2) 1.085(2) 1.084(2) 1.533(2) 1.531(2) 1.092(2) 1.092(2) 1.093(2)

Bond angles Ge–C(2)–H C(2)–C(4)–C(5) C(2)–C(5)–C(4) C(4)–C(2)–C(5) Ge–C(2)–C(4) Ge–C(2)–C(5) C(2)–Ge–C(6) H(1)–C(4)–H(2) H(3)–C(5)–H(4) C(2)–Ge–H(5) C(2)–Ge–H(6) Ge–C(6)–H(7) Ge–C(6)–H(8) Ge–C(6)–H(9) H(7)–C(6)–H(8) H(8)–C(6)–H(9) H(7)–C(6)–H(9)

θ0 [deg] a

Dihedral angles C(6)–Ge–C(2)–C(4) H(7)–C(6)–Ge–C(2)

τ0 [deg] a

483

116.4(5) 60.4(5) 60.3(5) 59.3(5) 120.1(5) 119.2(5) 110.6(5) 114.8(5) 114.8(5) 106.4(5) 110.7(5) 110.8(5) 110.0(5) 110.3(5) 108.7(5) 108.6(5) 108.5(5)

-151.8(5) 177.3(5)

Copyright 2010 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last digit.

Both the gauche and syn conformers, characterized by the synclinal and synperiplanar C(6)–Ge–C(2)…X torsional angle, respectively (X is bisector of the C(4)–C(2)–C(5) angle), were identified in the temperaturedependent IR and Raman vibrational spectra. The percentage of the less stable syn conformer was estimated to be 30(3) % at ambient temperature. The r0 structural parameters of the gauche conformer were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of five isotopic species (main, 70Ge, 72Ge, 73Ge and 76Ge). Durig JR, Panikar SS, Guirgis GA, Gounev TK, Klæboe P, Horn A, Nielsen CJ, Peebles RA, Peebles SA, Liberatore RJ (2010) Conformational stability, r0 structural parameters, barriers to internal rotation, vibrational assignments and ab initio calculations of c-C3H5GeH2CH3. J Mol Struct 969(1-3):55-68

581 CAS RN: 86280-03-7 MGD RN: 737266 MW augmented by

Cyclobutylgermane C4H10Ge Cs

484

6 Molecules with Four Carbon Atoms

QC calculations

equatorial r0 [Å] a 1.952(5) 1.557(3) 1.551(3) 1.096(2) 1.095(2) 1.093(2) 1.093(2) 1.094(2) 1.532(2) 1.531(2)

axial r0 [Å] a 1.950(5) 1.565(3) 1.551(3) 1.095(2) 1.094(2) 1.095(2) 1.093(2) 1.092(2) 1.532(2) 1.531(2)

Bond angles C(2)–C(1)–Ge C(2)–C(1)–C(2) C(3)–C(2)–C(1) C(2)–C(3)–C(2) H–C(1)–C(2) H–C(1)–Ge H(1)–C(2)–C(1) H(1)–C(2)–C(3) H(2)–C(2)–C(1) H(2)–C(2)–C(3) H(1)–C(2)–H(2) H(1)–C(3)–C(2) H(2)–C(3)–C(2) H(1)–C(3)–H(2) C(1)–Ge–H(1) C(1)–Ge–H(2) H(1)–Ge–H(2) H(1)–Ge–H(1)

θ0 [deg] a

θ0 [deg] a

Dihedral angles φb H(2)–Ge–C(1)…C(3)

τ0 [deg] a

Bonds Ge–C(1) C(1)–C(2) C(2)–C(3) C(1)–H C(2)–H(1) C(2)–H(2) C(3)–H(1) C(3)–H(2) Ge–H(2) Ge–H(1)

118.6(5) 88.3(5) 87.8(5) 88.7(5) 109.7(5) 110.2(5) 111.1(5) 108.1(5) 118.0(5) 121.1(5) 109.2(5) 118.9(5) 109.6(5) 109.5(5) 111.3(5) 108.2(5) 108.6(5) 108.7(5)

29.1(5) 0

113.4(5) 88.0(5) 88.8(5) 89.0(5) 116.3(5) 108.5(5) 118.8(5) 120.0(5) 110.5(5) 108.4(5) 108.7(5) 109.5(5) 119.1(5) 109.1(5) 110.2(5) 109.7(5) 108.7(5) 109.2(5)

GeH3

equatorial

axial

τ0 [deg] a 25.1(5) 0

Copyright 2012 with permission from Elsevier.

a b

Parenthesized estimated uncertainties in units of the last significant digit. Puckering angle defined as the angle between the C(3)–C(2)…C(2') and C(2)…C(2')–C(1) planes.

The r0 structures of the equatorial and axial conformers were determined from the previously published experimental ground-state rotational constants of three isotopic species (main, 72Ge and 74Ge) combined with structural parameters from MP2_full/6-311+G(d,p) calculation. The axial conformer was estimated to be present by temperature-dependent IR vibrational spectroscopy in amount of 37(1) % (at ambient temperature). Guirgis GA, Klaassen JJ, Deodhar BS, Sawant DK, Panikar SS, Dukes HW, Wyatt JK, Durig JR (2012) Structure and conformation studies from temperature dependent infrared spectra of xenon solutions and ab initio calculations of cyclobutylgermane. Spectrochim Acta A 99:266-278

6 Molecules with Four Carbon Atoms

485

582 CAS RN: 78-92-2 MGD RN: 917542 MW supported by ab initio calculations

2-Butanol sec-Butyl alcohol C4H10O C1 OH

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4)

rs [Å] a 1.540 1.522 1.529

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4)

θs [deg] a

CH3

H 3C

111.6 112.6

Copyright 2009 with permission from Elsevier.

a

Uncertainties were not given in the original paper.

The rotational spectrum of 2-butanol was recorded in a supersonicjet by a Balle-Flygare-type FTMW spectrometer in the spectral range between 4.5 and 18.0 GHz. Four conformers, characterized by different sets of the H–O–C–C(ethyl), C–C–C–C and O–C–C–C torsional angles, were detected. The Kraitchman substitution coordinates for the carbon skeleton of the most stable conformer (e-ga with the antiperiplanar H–O–C–C(ethyl), synclinal C–C–C–C and antiperiplanar O–C–C–C torsional angles, denoted as e-ga) were determined from the ground-state rotational constants of five isotopic species (main and four 13C). The presented rs structure is derived from these coordinates by authors of this book. King AK, Howard BJ (2009) An investigation into the relaxation of the conformers of butan-2-ol in a supersonic expansion. J Mol Spectrosc 257(2):205-212

583 CAS RN: 56955-16-9 MGD RN: 141723 MW augmented by ab initio calculations

1,4-Dioxane – water (1/1) p-Dioxane – water (1/1) C4H10O3 O Cs O H

Distance O(1)…O(7)

r0 [Å] a 2.865(4)

Angle O(7)…O(1)…X b

θ0 [deg] a 122.0(1)

Reprinted by permission of Taylor & Francis Ltd. Final version received 6 March 2014

a b

Parenthesized uncertainty in units of the last significant digit. X is the midpoint of C(2)–C(6).

O

H

486

6 Molecules with Four Carbon Atoms

The rotational spectra of the title complex were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 18.5 GHz. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 17O and two D); the remaining structural parameters were constrained to the values from MP2/6-311++G(d,p) calculations. Gou Q, Evangelisti L, Feng G, Guidetti G, Caminati W (2014) Effective orientation of water in 1,4dioxane⋅⋅⋅water: the rotational spectrum of the H217O isotopologue. Mol Phys 112(18):2419-2423

584 CAS RN: MGD RN: 320922 MW augmented by ab initio calculations

2-Hydroxypropanoic acid methyl ester – water (1/1) Methyl lactate – water (1/1) C4H10O4 C1 O H3C

a

Bonds O(6)…H(1) H(2)–O(6) H(3)–O(6) H(2)...O(4)

r0 [Å] 1.968(4) 1.038(44) 0.964(33) 1.846 b

Angles O(6)...H(1)–O(1) H(2)–O(6)…H(1)

θ0 [deg] a

Dihedral angles O(6)…H(1)–O(1)–C(2) H(2)–O(6)…H(1)–O(1)

τ0 [deg] a -55.3(5) -2.5(11)

O

CH3

O H

H

OH

162.2(1) c 78.2(19)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c Angle definition or angle value is misprinted in the original paper. b

Rotational spectra of the title complex were recorded by chirped-pulse and cavity based FTMW spectrometers between 8 and 18 GHz. The partial r0 structure of this chiral complex was determined from the ground-state rotational constants of seven isotopic species (main, 18O, three D and two D2); the remaining structural parameters were fixed to the values from MP2/6-311++G(d,p) calculation. Thomas J, Sukhorukov O, Jäger W, Xu Y (2014) Direct spectroscopic detection of the orientation of free OH groups in methyl lactate-(water)1,2 clusters: Hydration of a chiral hydroxyl ester. Angew Chem 126(4):11751178; Angew Chem Int Ed 53(4):1156-1159

585 CAS RN: 54690-68-5 MGD RN: 126930 MW augmented by

Cyclopropylmethylsilane C4H10Si C1

6 Molecules with Four Carbon Atoms

ab initio calculations

487

H

H

Bonds Si(1)–C(2) C(2)–C(4) C(2)–C(5) C(4)–C(5) Si(1)–C(6) C(2)–H C(4)–H(1) C(4)–H(2) C(5)–H(3) C(5)–H(4) Si(1)–H(5) Si(1)–H(6) C(6)–H(7) C(6)–H(8) C(6)–H(9)

r0 [Å] a 1.852(5) 1.518(3) 1.519(3) 1.500(3) 1.871(5) 1.088(2) 1.085(2) 1.084(2) 1.085(2) 1.084(2) 1.489(2) 1.488(2) 1.094(2) 1.093(2) 1.094(2)

Bond angles Si(1)–C(2)–H C(2)–C(4)–C(5) C(2)–C(5)–C(4) C(4)–C(2)–C(5) Si(1)–C(2)–C(4) Si(1)–C(2)–C(5) C(2)–Si(1)–C(6) H(1)–C(4)–H(2) H(3)–C(5)–H(4) C(2)–Si(1)–H(5) C(2)–Si(1)–H(6) Si(1)–C(6)–H(7) Si(1)–C(6)–H(8) Si(1)–C(6)–H(9) H(7)–C(6)–H(8) H(8)–C(6)–H(9) H(7)–C(6)–H(9)

θ0 [deg] a

Dihedral angles C(6)–Si(1)–C(2)–C(4) H(7)–C(6)–Si(1)–C(2)

τ0 [deg] a

Si CH3

117.1(5) 60.5(5) 60.4(5) 59.1(5) 119.9(5) 119.2(5) 111.5(5) 114.9(5) 114.9(5) 106.5(5) 110.6(5) 111.5(5) 110.6(5) 110.9(5) 108.0(5) 107.9(5) 107.8(5)

-152.9(5) 178.5(5)

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectra of cyclopropylmethylsilane were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 15.5 GHz. Only the gauche conformer (with the anticlinal‒ C(6)–Si(1)–C(2)–C(4) moiety) was observed. The r0 structure was determined by fitting the MP2/6-311+G(d) structure to the experimental ground-state rotational constants of three isotopic species (main, 29Si and 30Si) in natural abundance. From the splitting of the observed transitions, the barrier to internal rotation of the methyl group was determined to be 6.671(9) kJ mol‒1.

488

6 Molecules with Four Carbon Atoms

Foellmer MD, Murray JM, Serafin MM, Steber AL, Peebles RA, Peebles SA, Eichenberger JL, Guirgis GA, Wurrey CJ (2009) Microwave spectra and barrier to internal rotation in cyclopropylmethylsilane. J Phys Chem A 113(21):6077-6082

586 CAS RN: 80249-73-6 MGD RN: 968277 MW augmented by QC calculations

Cyclobutylsilane C4H10Si Cs (equatorial) Cs (axial)

equatorial r0 [Å] a 1.879(3) 1.562(3) 1.551(3) 1.097(2) 1.096(2) 1.093(2) 1.093(2) 1.094(2) 1.480(3) 1.480(3)

axial r0 [Å] a 1.884(3) 1.561(3) 1.553(3) 1.096(2) 1.094(2) 1.094(2) 1.093(2) 1.092(2) 1.480(3) 1.479(3)

Bond angles C(2)–C(1)–Si C(2)–C(1)–C(2) C(3)–C(2)–C(1) C(2)–C(3)–C(2) H–C(1)–C(2) H–C(1)–Si H(1)–C(2)–C(1) H(1)–C(2)–C(3) H(2)–C(2)–C(1) H(2)–C(2)–C(3) H(1)–C(2)–H(2) H(1)–C(3)–C(2) H(2)–C(3)–C(2) H(1)–C(3)–H(2) C(1)–Si–H(1) C(1)–Si–H(2) H(1)–Si–H(2) H(2)–Si–H(2)

θ0 [deg] a

θ0 [deg] a

Dihedral angles φb H(1)–Si–C(1)…C(3)

τ0 [deg] a

Bonds C(1)–Si C(1)–C(2) C(2)–C(3) C(1)–H C(2)–H(1) C(2)–H(2) C(3)–H(1) C(3)–H(2) Si–H(1) Si–H(2)

118.6(5) 88.2(5) 87.8(5) 88.9(5) 109.3(5) 110.8(5) 111.0(5) 108.2(5) 117.9(5) 121.1(5) 109.2(5) 118.9(5) 109.5(5) 109.4(5) 108.5(5) 111.1(5) 108.7(5) 108.7(5)

29.0(5) 0

SiH3

equatorial

113.2(5) 88.4(5) 88.9(5) 89.0(5) 116.2(5) 108.8(5) 118.7(5) 120.2(5) 110.8(5) 108.0(5) 108.8(5) 109.2(5) 119.4(5) 109.1(5) 110.1(5) 110.3(5) 108.5(5) 109.0(5)

τ0 [deg] a

axial

23.5(5) 0

Copyright 2012 with permission from Elsevier.

a b

Parenthesized estimated uncertainties in units of the last significant digit. Puckering angle defined as the angle between the C(3)–C(2)…C(2) and C(2)…C(2)–C(1) planes.

The equatorial and axial conformers were identified in the temperature-dependent IR vibrational spectra. The enthalpy difference between the more stable equatorial conformer and the axial one was estimated to be 0.81(8)

6 Molecules with Four Carbon Atoms

489

kJ mol-1 by temperature-dependent IR vibrational spectroscopy. The percentage of the axial conformer was estimated to be 42(1) % (at ambient temperature). The r0 structural parameters of each conformers were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of the parent species. Klaassen JJ, Panikar SS, Guirgis GA, Dukes HW, Wyatt JK, Durig JR (2013) Conformational and structural studies of cyclobutylsilane from temperature dependent infrared spectra of xenon solutions and ab initio calculations. J Mol Struct 1032:254-264

587 CAS RN: 288-06-2 MGD RN: 647120 MW

Silacyclopentane C4H10Si C2

Bonds Si–C(1) C(1)–C(2) C(2)–C(2ꞌ)

r0 [Å] a 1.8860(16) 1.5449(27) 1.5296 b

rs [Å] a 1.8806(13) 1.557(3) 1.531(5)

Bond angles C(1)–Si–C(1ꞌ) Si–C(1)–C(2) C(1)–C(2)–C(2ꞌ)

θ0 [deg] a

θs [deg] a

Dihedral angles C(1)–Si–C(1ꞌ)–C(2ꞌ) C(1)–C(2)–C(2ꞌ)–C(1ꞌ) Si–C(1)–C(2)–C(2ꞌ)

τ0 [deg] a

96.19(12) 103.22(13) 108.76 b

SiH2

96.49(16) 102.29(13) 108.17(26)

12.88(4) 49.78 b -36.36 b

Copyright 2011 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectra of the title compound were recorded in a supersonic jet by Balle-Flygare type and chirpedpulse FTMW spectrometers in the spectral region between 6 and 24 GHz. The partial r0 structure was determined from the experimental ground-state rotational constants of five isotopic species (main, two 13C, 29Si and 30Si); the remaining structural parameters were assumed at the values of the previously published GED structure. Due to non-zero cs coordinates for the carbon atoms, C2v symmetry was excluded. Chen Z, van Wijngaarden J (2011) Pure rotational spectrum and structural determination of silacyclopentane. J Mol Spectrosc 269(1):137-140

588

4-Amino-1-butanol

CAS RN: 13325-10-5

MGD RN: 533940 MW augmented by ab initio calculations

H 2N

C4H11NO C1 OH

490

6 Molecules with Four Carbon Atoms

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–O O...N

r0 [Å] a 1.531(3) 1.522(3) 1.533(2) 1.416(3) 2.954 b

Bond angles

θ0 [deg] a

Dihedral angles C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–N

τ0 [deg] a -71.0(3) 75.1(3)

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–N O–C(1)–C(2)

116.9(1) 116.9(1) 111.9(1) 114.3(1)

Copyright 2017 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the title compound was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 9 and 20 GHz. Only one conformer, characterized by the synclinal C(1)–C(2)–C(3)–C(4), C(2)–C(3)–C(4)–N and C(2)–C(1)– O–H torsional angles, was detected. According to prediction of MP2/6-311++G(d,p) calculations, this conformer, stabilized by the N…HO hydrogen bond, is the most stable one and separated from the next conformer by 4.87 kJ mol-1. The r0 structure of the heavy-atom skeleton was determined from the ground-state rotational constants of five isotopic species (main and four singly substituted 13C). Khalil AS, Duguay TM, Lavrich RJ (2017) Conformation and hydrogen bonding in 4-aminobutanol. J Mol Struct 1138:12-16

589 CAS RN: 58828-90-3 MGD RN: 479377 MW supported by ab initio calculations

N,N-Dimethylmethanamine – formic acid (1/1) Trimethylamine – formic acid (1/1) C4H11NO2 Cs CH3

O

N

Distance Rcm b

r0 [Å] a 3.24406

Angles

θ0 [deg] a

c

ϕ φd

104.7 23.7

Reprinted with permission. Copyright 2016 American Chemical Society.

H 3C

CH3

H

OH

6 Molecules with Four Carbon Atoms

491

a

Uncertainties were not given in the original paper. Distance between centers of mass of the monomer subunits. c Angle between C(2)–O(4) and the z axis of the complex. d Angle between the C3 axis of amine and the z axis of the complex. b

The rotational spectrum of the binary complex of trimethylamine with formic acid was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 5.4 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main, 13 C and D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Mackenzie RB, Dewberry CT, Leopold KR (2016) The trimethylamine-formic acid complex: microwave characterization of a prototype for potential precursors to atmospheric aerosol. J Phys Chem A 120(14):22682273

590 CAS RN: 1433100-49-2 MGD RN: 335580 MW supported by ab initio calculations

2-Hydroxypropanoic acid methyl ester – ammonia (1/1) Methyl lactate – ammonia (1/1) C4H11NO3 C1 O

H3C

O

a

Distances N…O(1) N…H(1) H(2)…O(2)

r0 [Å] 2.887(5) 1.928 b 2.359 b

Angles N…O(1)–C(1) H(2)–N…H(1)

θ0 [deg] a

Dihedral angle N…O(1)–C(1)–C(2)

τ0 [deg] a 52.83(3)

CH3

N H

H H

OH

110.58(1) 97(4)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

Rotational spectra were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 8 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 15N). The rotational barriers to internal rotation of the ester methyl and ammonia group were determined to be 4.778(16) and 2.452(2) kJ mol-1, respectively. Thomas J, Sukhorukov O, Jäger W, Xu Y (2013) Chirped-pulse and cavity-based Fourier transform microwave spectra of the methyl lactate-ammonia adduct. Angew Chem 125(16):4498-4501; Angew Chem Int Ed 52(16):4402-4405

492

6 Molecules with Four Carbon Atoms

591 CAS RN: 33584-41-7 MGD RN: 370403 GED supported by ab initio computations

1-(Trimethylsilyl)methanol 1-nitrate C4H11NO3Si Cs H 3C H 3C

a

Bonds Si–C Si–C(m) c Si–C(1) C–O N–O(3) N=O N=O(2) N=O(1) C–H

rh1 [Å] 1.882(1) b 1.874(1) d 1.907(3) d 1.437(4) 1.435(3) 1.206(1) b 1.208(2) e 1.204(2) e 1.103(3) f

Bond angles C(m)–Si–C(m) c Si–C–O(3) C–O–N O(1)=N=O(2) H–C–H

θh1 [deg] a

Other angle tilt [Si(CH3)3] g

τh1 [deg] a

CH3 Si

O

O N O

110.7(4) 108.3(3) 113.6(4) 131.3(7) 109.5(3) f

1.6(5) f

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Average value. c C(m) is carbon atom in the methyl group. d Difference between the Si–C(m) and C(1)–Si bond lengths was restrained to the value from MP2/TZVPP computation. e Difference between the N=O bond lengths was restrained to the value from computation as indicated above. f Restrained to the value from computation as indicated above. g Defined as a decrease in the C(1)–Si–C(3) angle with respect to that required for C3v symmetry. b

The GED experiment was carried out at room temperature. Local C3v symmetry for the Si(CH3)3 group and each of the CH3 groups as well as overall Cs symmetry were assumed. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from HF/6-31G* computation. Evangelisti C, Klapötke TM, Krumm B, Nieder A, Berger RJF, Hayes SA, Mitzel NW, Troegel D, Tacke R (2010) Sila-substitution of alkyl nitrates: Synthesis, structural characterization, and sensitivity studies of highly explosive (nitratomethyl)-, bis(nitratomethyl)-, and tris(nitratomethyl)silanes and their corresponding carbon analogues. Inorg Chem 49 (11):4865-4880

592

1,1ꞌ-Oxybismethane – 1,1ꞌ-thiobismethane (1/1)

6 Molecules with Four Carbon Atoms

493

CAS RN: MGD RN: 460304 MW supported by ab initio calculations

Distances Rcm b C–S

r0 [Å] a 3.970

Bond angle C–S–C

Dimethyl ether – dimethyl sulfide (1/1) C4H12OS Cs S

O H 3C

CH3

H3C

CH3

rs [Å] a 1.783

θs [deg] a 101.3

Reprinted with permission. Copyright 2015 American Chemical Society.

a b

Uncertainty was not given in the original paper. Distance between centers of mass in both monomer subunits.

The rotational spectrum of the binary complex of dimethyl ether with dimethyl sulfide was recorded in a supersonic jet by a pulsed-jet Balle-Flygare type FTMW spectroscometer in the frequency region between 4 and 24 GHz. The partial effective structure r0 was determined from the ground-state rotational constants of four isotopic species (main, 34S and two 13C) under the assumption that the structural parameters were not changed upon complexation. Moreover a partial rs structure was obtained. Kawashima Y, Tatamitani Y, Mase T, Hirota E (2015) Dimethyl sulfide-dimethyl ether and ethylene oxideethylene sulfide complexes investigated by Fourier transform microwave spectroscopy and ab initio calculation. J Phys Chem A 119(42) 10602-10612

593 CAS RN: 288376-89-6 MGD RN: 215821 MW augmented by ab initio calculations

2-Methyl-2-propanol – water (1/1) tert-Butanol – water (1/1) C4H12O2 C1 H3C

a

Distances O(1)...O(2) O(1)...H(2)

r0 [Å] 2.859 1.903

Angles O(2)…O(1)–C(1) O(2)–H(2)…O(1) C(2)–C(1)–O(1)…O(2) C(1)–O(1)…O(2)–H(2) H(3)–O(2)–H(2)…O(1)

θ0 [deg] a 109.2 168.4 178.8 151.9 169.6

Reproduced with permission from the PCCP Owner Societies.

a

Uncertainties were not given in the original paper.

H 3C

CH3

OH

O H

H

494

6 Molecules with Four Carbon Atoms

The rotational spectra of the title complex were recorded in a supersonic jet by a Balle–Flygare type FTMW spectrometer in the frequency region between 6 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, 18 O, three D1 and three D2); the values of the remaining structural parameters were adopted from MP2/6311++G(d,p) calculation. The internal rotation of the hydroxyl group and the oscillations of water molecule were described by a large amplitude motion model. Evangelisti L, Caminati W (2010) Internal dynamics in complexes of water with organic molecules. Details of the internal motions in tert-butylalcohol-water. Phys Chem Chem Phys 12(43):14433-14441 594

Ethanol dimer

CAS RN: 42845-45-4

MGD RN: 148447 MW supported by QC calculations

C4H12O2

C1 (aa) C1 (gg) C1 (g‒a)

H 3C

aa r0 [Å] a 1.521(35) 1.351(28) 2.889(22) 1.479(32) 1.492(42)

aa rs [Å] a 1.572(71) 1.407(22) 2.803(20) 1.352(64) 1.492(80)

gg rs [Å] a 1.51(10)

g ‒a rs [Å] a 1.461(49)

1.443(72)

1.529(59)

Angles C(1)–C(2)–O(3) C(2)–O(3)…O(4) O(4)–C(5)–C(6)

θ0 [deg] a

θs [deg] a

θs [deg]

θs [deg]

Dihedral angles C(1)–C(2)–O(3)…O(4) C(2)–O(3)…O(4)–C(5) C(1)–C(2)…C(6)–C(5)

τ0 [deg] a

τs [deg] a 168.3(23) -97.9(56) -138.3(83)

τs [deg] a

τs [deg] a

-49.3(89)

63.5(41)

Distances C(1)–C(2) C(2)–O(3) O(3)…O(4) O(4)–C(5) C(5)–C(6)

116.0(41) 110.32(81) 105.9(11)

-112.5(31)

107.6(63) 112.8(15) 109.7(19)

OH

Copyright 2017 with permission from Elsevier [a]. a

Parenthesized uncertainties in units of the last significant digit.

aa

gg

g ‒a

2

6 Molecules with Four Carbon Atoms

495

The rotational spectrum of the ethanol dimer was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8 GHz. The singly substituted 13C isotopic species and some of the 18O isotopic species were studied in natural abundance. Three new conformers (aa, ag, and g‒g), characterized by different combinations of the antiperiplanar and synclinal C–C–O–H chains, were identified together with the three ones (gg, g‒a and ga) previously observed in Ref. [b]. The rs structures of the heavy-atom skeletons of the most abundant conformers, aa, gg and g‒a, were determined from ground-state rotational constants of seven, five and five isotopic species, respectively. a. Loru D, Peña I, Sanz ME (2017) Ethanol dimer: Observation of three new conformers by broadband rotational spectroscopy. J Mol Spectrosc 335(5):93-101 b. Hearn JPI, Cobley RV, Howard BJ (2005) High-resolution spectroscopy of induced chiral dimers: A study of the dimers of ethanol by Fourier transform microwave spectroscopy. J Chem Phys 123(13):134324/1-134324/7

595 CAS RN: 138385-77-0 MGD RN: 327253 GED augmented by QC computations

Bonds Si–C Si–O C–C C–H O–H

rh1 [Å] a 1.879(3) 1.640(1) 1.540(2) 1.118(2) 0.940(4)

Bond angles C–Si–O C–C–Si Si–O–H C–C–H C–C–C O–Si–O

θh1 [deg] a

Dihedral angle C–Si–O–H

τh1 [deg] a

1-(1,1-Dimethylethyl)silanetriol C4H12O3Si C3 (staggered) H 3C H 3C H3C

OH

Si

OH OH

111.2(2) 110.5(3) 112.9(8) 111.4(5) b 108.4(3) b 107.7(3) b

122.9(8)

Reproduced with permission from The Royal Society of Chemistry.

a b

Parenthesized uncertainties given in units of the last significant digit were not identified, probably 1σ values. Dependent parameter.

The GED experiment was carried out at Tnozzle = 436(5) K. The title compound was found to exist in the gas phase as monomeric molecules, i.e. no hydrogen bonded aggregates were detected. Local C3 symmetry was assumed both for the tert-butyl and silanetriol group, as well as for each of the methyl groups. The tert-butyl was assumed to have staggered conformation with respect to the silanetriol group. Spirk S, Berger RJF, Reuter CG, Pietschnig R, Mitzel NW (2012) Silanetriols in the gas phase: Single molecules vs. hydrogen-bonded dimers. Dalton Trans 41 (13):3630-3632

496

6 Molecules with Four Carbon Atoms

596 CAS RN: 14151-38-3 MGD RN: 317653 GED augmented by QC computations

1,2-Disilacyclohexane C4H12Si2 C2 SiH2

Bonds Si–Si Si–C C(3)–C(4) C(4)–C(5) Si–H C–H

rh1[Å] a 2.324(4) 1.884(3) 1.548(3) b 1.544(3) b 1.468(10) c 1.105(5) c

Bond angles Si(1)–Si(2)–C(3) Si(2)–C(3)–C(4) C(3)–C(4)–C(5) H–Si–H H–C–H

θh1 [deg] a

Dihedral angles C(6)–Si(1)–Si(2)–C(3) Si(1)–Si(2)–C(3)–C(4) Si(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6)

τh1 [deg] a

SiH2

101.5(11) 113.8(13) d 115.8(18) d 108.2 e 106.3(36) c

-40.5(46) 49.5(28) d -66.2(22) d 73.0(42)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Difference between the C(3)–C(4) and C(4)–C(5) bond lengths was fixed at the value from MP2/cc-pVTZ computation. c Average value. d Dependent parameter. e Assumed at the value from computation as indicated above. b

The GED experiment was carried out at room temperature. The title molecule was found to exist as a single conformer possessing the C2 symmetry with a symmetry axis through the mid-points of the Si(1)–Si(2) and C(4)–C(5) bonds. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Arnason I, Gudnason PI, Björnsson R, Oberhammer H (2011) Gas phase structures, energetics, and potential energy surfaces of disilacyclohexanes. J Phys Chem A 115 (35):10000-10008

597 CAS RN: 407-87-4 MGD RN: 317481 GED augmented by QC computations

1,3-Disilacyclohexane C4H12Si2 Cs

6 Molecules with Four Carbon Atoms

Bonds Si(1)–C(2) Si(1)–C(6) C–C Si–H C–H

rh1[Å] a 1.870(1) b 1.877(1) b 1.552(4) 1.465(10) c 1.101(5) c

Bond angles Si(1)–C(2)–Si(3) C(2)–Si(3)–C(4) Si(3)–C(4)–C(5) C(4)–C(5)–C(6) H–Si–H H–C–H

θh1 [deg] a

Dihedral angles flap(C(2)) f flap(C(5)) g Si(1)–C(2)–Si(3)–C(4) C(2)–Si(3)–C(4)–C(5) Si(3)–C(4)–C(5)–C(6)

τh1 [deg] a

497

SiH2

Si H2

110.5(3) 109.0(16) d 113.6(10) d 112.5(11) 108.2 e 105.5(23) c

40.0(23) 58.1(12) -42.4(22) d 53.8(19) d -66.7(17) d

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Difference between the Si(1)–C(2) and Si(1)–C(6) bond lengths was fixed at the value from MP2/cc-pVTZ computation. c Average value. d Dependent parameter. e Assumed at the value from computation as indicated above. f Acute angle between the SiC(2)Si and SiSiC(4)C(6) planes. g Acute angle between the C(4)C(5)C(6) and C(4)C(6)SiSi planes. b

The GED experiment was carried out at room temperature. The title molecule was found to exist as a single conformer possessing a chair conformation and Cs overall symmetry. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Arnason I, Gudnason PI, Björnsson R, Oberhammer H (2011) Gas phase structures, energetics, and potential energy surfaces of disilacyclohexanes. J Phys Chem A 115 (35):10000-10008

598 CAS RN: 3290-84-6 MGD RN: 317303 GED augmented by QC computations

Bonds Si–C C–C Si–H C–H

1,4-Disilacyclohexane C4H12Si2 C2h SiH2

rh1[Å] a 1.877(1) 1.559(4) 1.467(8) b 1.103(5) b

H2Si

498

6 Molecules with Four Carbon Atoms

Bond angles C–Si–C H–Si–H Si–C–C H–C–H

θh1 [deg] a

Dihedral angles Si–C–C–Si C–Si–C–C flap(Si) e

τh1 [deg] a

109.4(6) 108.6 c 112.4(5) d 106.8(24)

56.0(6) d -54.4(9) d 48.7(8)

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Average value. c Assumed at the value from MP2/cc-pVTZ computation. d Dependent parameter. e Acute angle between the CSiC and CCCC planes. b

The GED experiment was carried out at room temperature. The best fit to the experimental intensities was obtained for the model of a single conformer possessing a chair conformation and C2h overall symmetry. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated with harmonic force constants from B3LYP/cc-pVTZ computation. Arnason I, Gudnason PI, Björnsson R, Oberhammer H (2011) Gas phase structures, energetics, and potential energy surfaces of disilacyclohexanes. J Phys Chem A 115 (35):10000-10008

599 CAS RN: 23347-22-0 MGD RN: 539655 GED combined with MS and supplemented by DFT computations

1,2,5-Thiadiazole-3,4-dicarbonitrile 3,4-Dicyano-1,2,5-thiadiazole C 4N 4S C2v N N

Bonds S–N(3) N(3)=C(2) C(2)–C(1) C(1)≡N(1)

rh1 [Å] a 1.641(4) 1.326(4) 1.414(6) 1.159(5) b

Bond angles N(3)–S–N(3ʹ) N(3)=C(2)–C(2ʹ) S–N(3)=C(2) N(3)=C(2)–C(1) C(2)–C(1)≡N(1)

θh1 [deg] a

C

S N

C N

98.2(10) 112.7(5) 108.2(7) 122.4(6) 180.0 c

Reproduced with permission of ISUCT Publishing. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r for the bond lengths and 3σ values for the angles.

6 Molecules with Four Carbon Atoms b c

499

Independent parameters. Assumed.

The experiment was carried out at Teffusion cell = 860(5) K. The title molecule was found to be present in the vapor over [25H,27H-tetrakis[1,2,5]thiadiazolo[3,4-b:3',4'-g:3'',4''-l:3''',4'''-q]porphyrazin-14-SIV-atoκN25,κN26,κN27,κN28]zinc, C16N16S4Zn, as decomposition product in the ratio C16N16S4Zn : C4N4S = 10 : 90 (in mol%). Differences between similar parameters were assumed at the values from B3LYP/cc-pVTZ computations. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from DFT computation. Tverdova NV, Giricheva NI, Savelyev DS, Mikhailov MS, Vogt N, Koifman OI, Stuzhin PA, Girichev GV (2017) Molecular structure of tetrakis(1,2,5-thiadiazolo)-porphyrazinatozinc(II) in gaseous phase. Macroheterocycles 10(1): 27-30

600 CAS RN: 1435877-99-8 MGD RN: 400608 IR

Carbon disulfide tetramer C4S8 D2d S

a

Distances R1 b R2 c

r0 [Å] 4.970 1.833

Angle

θ0 [Å] a

ϕ

d

C

S

4

18.8

Copyright 2013 with permission from Elsevier.

a

Uncertainties were not given in the original paper. Separation of the C atoms of diagonally opposite monomers. c Distance between the centers of mass of two diagonally opposite monomer pairs. d Angle between the monomer axis and the tetramer symmetry axis. b

The rotationally resolved IR spectrum of the carbon disulfide tetramer was recorded in the region of the CS2 ν3 fundamental band at 1535 cm-1 using a pulsed supersonic-jet tunable diode laser spectrometer. The likely structure is a staggered and tilted barrel with D2d symmetry, in which the four monomer subunits are equivalent and the diagonally opposite monomers are coplanar. The r0 structure was determined under the assumption that the geometries of the monomer subunits were not changed upon complexation. Rezaei M, Norooz Oliaee J, Moazzen-Ahmadi N, McKellar ARW (2013) Infrared spectrum of the CS2 tetramer: Observation of a structure with D2d symmetry. Chem Phys Lett 570:12-15

500

6 Molecules with Four Carbon Atoms

References: 488 489 490 491 492

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6 Molecules with Four Carbon Atoms

566

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570 571

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577

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579

580

(a) Den T, Menzi S, Frey HM, Leutwyler S (2017) Accurate gas-phase structure of paradioxane by fs Raman rotational coherence spectroscopy and ab initio calculations. J Chem Phys 147(7):074306/1-074306/15 (b) Fargher M, Hedberg L, Hedberg K (2014) The molecular structure of gaseous 1,4-dioxane: An electron-diffraction reinvestigation aided by theoretical calculations. J Mol Struct 1071:4144 Favero LB, Caminati W (2009) Hydrated complexes of atmospheric interest: rotational spectrum of diacetyl-water. J Phys Chem A 113(52):14308-14311 Zinn S, Medcraft C, Betz T, Schnell M (2016) High-resolution rotational spectroscopy study of the smallest sugar dimer: Interplay of hydrogen bonds in the glycolaldehyde dimer. Angew Chem 128(20):6079-6084; Angew Chem Int Ed 55(20):5975-5980 Durig JR, Panikar SS, Obenchain DA, Bills BJ, Lohan PM, Peebles RA, Peebles SA, Groner P, Guirgis GA, Johnston MD (2012) Microwave, infrared and Raman spectra, r0 structural parameters, ab initio calculations and vibrational assignment of 1-fluoro-1-silacyclopentane. J Chem Phys 136(4):044306/1-044306/10 Stephens SL, Walker NR, Legon AC (2011) Internal rotation and halogen bonds in CF3I⋅⋅⋅NH3 and CF3I⋅⋅⋅N(CH3)3 probed by broadband rotational spectroscopy. Phys Chem Chem Phys 13(46):20736-20744 Defonsi Lestard ME, Tuttolomondo ME, Varetti EL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2010) Investigation of the gas-phase structure and rotational barrier of trimethylsilyl trifluoromethanesulfonate and comparison with covalent sulfonates. J Mol Struct 984 (1-3):376-382 Arsenault EA, Obenchain DA, Choi YJ, Blake TA, Cooke SA, Novick SE (2016) A study of 2iodobutane by rotational spectroscopy. J Phys Chem A 120(36):7145-7151 Durig JR, Ganguly A, El Defrawy AM, Guirgis GA, Gounev TK, Herrebout WA, van der Veken BJ (2009) Conformational stability, r0 structural parameters, barriers to internal rotation and vibrational assignment of cyclobutylamine. J Mol Struct 918(1-3):64-76 Durig JR, El-Defrawy AM, Ganguly A, Panikar SS, Soliman MS (2011) Conformational stability from variable-temperature infrared spectra of xenon solutions, r0 structural parameters, and vibrational assignment of pyrrolidine. J Phys Chem A 115(26):7473-7483 Canneva A, Erben MF, Romano RM, Vishnevskiy YV, Reuter CG, Mitzel NW, Della Védova CO (2015) The tructure and conformation of (CH3)3CSNO. Chem Eur J 21 (29):10436-10442 (a) Tarasov YI, Kochikov IV, Kovtun DM, Polenov EA, Ivanov AA (2017) Internal rotation and equilibrium structure of the 2-methyl-2-nitropropane molecule from joint processing of gas phase electron diffraction data, vibrational and microwave spectroscopy data, and quantum chemical calculation results. J Struct Chem (Engl Transl) / Zh Strukt Khim 58/58 (3/3):498507/525-534 (b) Shishkov IF, Sadova NI, Vilkov LV, Pankrushev YA (1983) Geometrical structure of dimethylnitromethane and trimethylnitromethane molecules in gaseous phase. J Struct Chem (Eng. Transl.) / Zh Strukt Khim 24/24 (2 /2): 25-30 /189-193 (c) Langridge-Smith PRR, Stevens R, Cox AP (1980) Microwave spectrum and barrier to internal rotation of 2-methyl-2.nitropropane, Me3CNO2. J Chem Soc Faraday Trans II 76:330338 Khaikin LS, Grikina OE, Kochikov IV, Stepanov NF (2014) Quantum-chemical calculations for silyl- and alkyl-pseudohalides X3YNCZ (X = H or CH3; Y = C or Si; Z = O, S, or Se) and electron diffraction study of the equilibrium molecular structure of (CH3)3SiNCSe. Russ J Phys Chem A/Zh Fiz Khim 88 / 88 (4 / 4):657-660 / 643-646 (a) Khaikin LS, Grikina OE, Stepanov NF (2010) A quantum-chemical and gas phase electron diffraction study of the structure of formylphosphine and acetyldimethylphosphine. Russ J Phys Chem A / Zh Fiz Khim 84 / 84 (10 / 10):1745-1751 / 1913-1919 (b) Khaikin LS, Andrutskaya LG, Grikina OE, Vilkov LV, El’natanov YI, Kostyanovskii RG (1977) Molecular structure of acetyldimethylphosphine, MeC(O)PMe2. I. Gas phase electron diffraction study. J Mol Struct 37:237-250 Montejo M, Wann DA, Rodríguez Ortega PG, Robertson HE, Márquez F, Rankin DWH, López Gonzáles JJ (2010) Conformational landscape of small organosilicon compounds from the combined use of gas electron diffraction, IR and Raman spectroscopies and quantum chemical calculations: diethyldichlorosilane. J Raman Spectrosc 41 (10):1323-1330 Durig JR, Panikar SS, Guirgis GA, Gounev TK, Klæboe P, Horn A, Nielsen CJ, Peebles RA, Peebles SA, Liberatore RJ (2010) Conformational stability, r0 structural parameters, barriers to internal rotation, vibrational assignments and ab initio calculations of c-C3H5GeH2CH3. J Mol Struct 969(1-3):55-68

6 References

505

581

Guirgis GA, Klaassen JJ, Deodhar BS, Sawant DK, Panikar SS, Dukes HW, Wyatt JK, Durig JR (2012) Structure and conformation studies from temperature dependent infrared spectra of xenon solutions and ab initio calculations of cyclobutylgermane. Spectrochim Acta A 99:266278 King AK, Howard BJ (2009) An investigation into the relaxation of the conformers of butan-2ol in a supersonic expansion. J Mol Spectrosc 257(2):205-212 Gou Q, Evangelisti L, Feng G, Guidetti G, Caminati W (2014) Effective orientation of water in 1,4-dioxane⋅⋅⋅water: the rotational spectrum of the H217O isotopologue. Mol Phys 112(18):2419-2423 Thomas J, Sukhorukov O, Jäger W, Xu Y (2014) Direct spectroscopic detection of the orientation of free OH groups in methyl lactate-(water)1,2 clusters: Hydration of a chiral hydroxyl ester. Angew Chem 126(4):1175-1178; Angew Chem Int Ed 53(4):1156-1159 Foellmer MD, Murray JM, Serafin MM, Steber AL, Peebles RA, Peebles SA, Eichenberger JL, Guirgis GA, Wurrey CJ (2009) Microwave spectra and barrier to internal rotation in cyclopropylmethylsilane. J Phys Chem A 113(21):6077-6082 Klaassen JJ, Panikar SS, Guirgis GA, Dukes HW, Wyatt JK, Durig JR (2013) Conformational and structural studies of cyclobutylsilane from temperature dependent infrared spectra of xenon solutions and ab initio calculations. J Mol Struct 1032:254-264 Chen Z, van Wijngaarden J (2011) Pure rotational spectrum and structural determination of silacyclopentane. J Mol Spectrosc 269(1):137-140 Khalil AS, Duguay TM, Lavrich RJ (2017) Conformation and hydrogen bonding in 4aminobutanol. J Mol Struct 1138:12-16 Mackenzie RB, Dewberry CT, Leopold KR (2016) The trimethylamine-formic acid complex: microwave characterization of a prototype for potential precursors to atmospheric aerosol. J Phys Chem A 120(14):2268-2273 Thomas J, Sukhorukov O, Jäger W, Xu Y (2013) Chirped-pulse and cavity-based Fourier transform microwave spectra of the methyl lactate-ammonia adduct. Angew Chem 125(16):4498-4501; Angew Chem Int Ed 52(16):4402-4405 Evangelisti C, Klapötke TM, Krumm B, Nieder A, Berger RJF, Hayes SA, Mitzel NW, Troegel D, Tacke R (2010) Sila-substitution of alkyl nitrates: Synthesis, structural characterization, and sensitivity studies of highly explosive (nitratomethyl)-, bis(nitratomethyl)-, and tris(nitratomethyl)silanes and their corresponding carbon analogues. Inorg Chem 49 (11):4865-4880 See 565. Evangelisti L, Caminati W (2010) Internal dynamics in complexes of water with organic molecules. Details of the internal motions in tert-butylalcohol-water. Phys Chem Chem Phys 12(43):14433-14441 (a) Loru D, Peña I, Sanz ME (2017) Ethanol dimer: Observation of three new conformers by broadband rotational spectroscopy. J Mol Spectrosc 335(5):93-101 (b) Hearn JPI, Cobley RV, Howard BJ (2005) High-resolution spectroscopy of induced chiral dimers: A study of the dimers of ethanol by Fourier transform microwave spectroscopy. J Chem Phys 123(13):134324/1-134324/7 Spirk S, Berger RJF, Reuter CG, Pietschnig R, Mitzel NW (2012) Silanetriols in the gas phase: Single molecules vs. hydrogen-bonded dimers. Dalton Trans 41 (13):3630-3632 Arnason I, Gudnason PI, Björnsson R, Oberhammer H (2011) Gas phase structures, energetics, and potential energy surfaces of disilacyclohexanes. J Phys Chem A 115 (35):10000-10008 See 596. See 596. Tverdova NV, Giricheva NI, Savelyev DS, Mikhailov MS, Vogt N, Koifman OI, Stuzhin PA, Girichev GV (2017) Molecular structure of tetrakis(1,2,5-thiadiazolo)-porphyrazinatozinc(II) in gaseous phase. Macroheterocycles 10(1): 27-30. Rezaei M, Norooz Oliaee J, Moazzen-Ahmadi N, McKellar ARW (2013) Infrared spectrum of the CS2 tetramer: Observation of a structure with D2d symmetry. Chem Phys Lett 570:12-15

582 583 584 585 586 587 588 589 590 591

592 593 594

595 596 597 598 599 600

Chapter 7. Molecules with Five Carbon Atoms

601 CAS RN: 559-40-0 MGD RN: 194648 MW supported by QC calculations

Octafluorocyclopentene C5F8 Cs

F

F

F

Bonds C(3)–C(4) C(2)–C(3) C(1)=C(2)

r0 [Å] a 1.559(6) 1.497(10) 1.339(5)

Bond angles C(3)–C(4)–C(5) C(2)–C(3)–C(4) C(1)=C(2)–C(3)

θ0 [deg] a

Dihedral angle

τ0 [deg]

φ

b

F F

F F

F

104.7(5) 103.03(30) 112.2(6)

21.6

Reprinted with permission. Copyright 2016 American Chemical Society. a b

Parenthesized uncertainties in units of the last significant digit. Angle between C(3)−C(4)−C(5) and C(5)−C(1)−C(2)−C(3) plane.

The rotational spectra of the title compound were recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the frequency region between 6 and 18 GHz. The r0 structure of the ring skeleton was determined from the ground-state rotational constants of four isotopic species (main and three 13C). Long BE, Arsenault EA, Obenchain DA, Choi YJ, Ocola EJ, Laane J, Pringle WC, Cooke SA (2016) Microwave spectra, structure, and ring-puckering vibration of octafluorocyclopentene. J Phys Chem A 120(43):8686-8690 602 CAS RN: 678-26-2 MGD RN: 226454 MW supported by ab initio calculations

Dodecafluoropentane Perfluoropentane C5F12 C2 F

F

F

F

F

Bonds C(1)–C(2) C(2)–C(3)

r0 [Å] a 1.554 1.532

rs [Å] a 1.552 1.517

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4)

θ0 [deg] a

θs [deg] a

115.6 113.9

F

F

F

F

F

F

F

115.9 113.2

© Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_7

507

508

7 Molecules with Five Carbon Atoms

Dihedral angle C(1)–C(2)–C(3)–C(4)

τ0 [deg] a 16.4

b

τs [deg] a 13.3 b

Reprinted with permission. Copyright 20010 American Chemical Society. a b

Uncertainties were not given in the original paper. Deviation from 180°.

The rotational spectrum of perfluoropentane was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 9 and 18 GHz. The r0 and rs structures of the carbon skeleton were determined from the ground-state rotational constants of four isotopic species (main and three 13C). The molecule was found to have a helical structure with C2 symmetry. Fournier JA, Bohn RK, Montgomery JA, Onda M (2010) Helical C2 structure of perfluoropentane and the C2v structure of perfluoropropane. J Phys Chem A 114(2):1118-1122

603 CAS RN: 1902167-98-9 MGD RN: 488602 MW augmented by ab initio calculations

2,3,4,5,6-Pentafluoropyridine – water (1/1) C5H2F5NO Cs

F

F

F

O H

H

a

Distance O...N

r0 [Å] 3.163(3)

Angles C(3)–N–C(2) O…N…C(6)

θ0 [deg] a

F

N

F

117.55(5) 70.4(1)

Reprinted with permission. Copyright 2016 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the binary complex of pentafluoropyridine with water were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the rotational constants of four isotopic species (main, 18O and two D) constraining the remaining structural parameters to the values from MP2/6-311++G(d,p) calculation (with correction for basis set superposition error by means of counterpoise procedure). The water subunit was found to be located above the aromatic ring plane with the oxygen lone pair pointing to the center of the ring. Calabrese C, Gou Q, Maris A, Caminati W, Melandri S (2016) Probing the lone pair⋅⋅⋅π-hole interaction in perfluorinated heteroaromatic rings: The rotational spectrum of pentafluoropyridine⋅water. J Phys Chem Lett 7(8):1513-1517

604 CAS RN: 75092-43-2 MGD RN: 515111 MW augmented by

(3Z)-1,1,1,5,5,5-Hexafluoro-4-hydroxy-3-penten-2-one C5H2F6O2 Cs

7 Molecules with Five Carbon Atoms

509

ab initio calculations

O

OH

F

F a

Bonds C(1)–C(2) C(2)–C(3) C(3)=C(4) C(4)–C(5) C(2)=O(6) C(4)–O(7) C(1)–F(10) C(1)–F(8) C(5)–F(13) C(5)–F(11) C(3)–H O(7)–H

rs [Å] 1.542(4) 1.434(9) 1.335(9) 1.523(4) 1.234 b 1.321 b 1.324 b 1.344 b 1.338 b 1.339 b 1.099(6) 0.988 b

Bond angles C(1)–C(2)–C(3) C(2)–C(3)=C(4) C(3)=C(4)–C(5) O(6)=C(2)–C(3) O(7)–C(4)=C(3) F(8)–C(1)–C(2) F(9)−C(1)−C(2) F(11)–C(5)–C(4) F(12)–C(5)–C(4) H–C(3)–C(2) H–O(7)–C(4)

θs [deg] a

Dihedral angles F(9)–C(1)…C(3)–H F(12)–C(5)–C(4)–O(7)

τs [deg]

F

F

F

F

117.2(9) 116.6(9) 122(1) 124.4 b 125.7 b 112.1 b 109.6 b 111.4 b 110.3 b 123(1) 106.0 b

-59.2 b 59.7 b

Copyright 2009 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed at the value from MP2/6-311++G(d,p) calculations.

The rotational spectrum of hexafluoroacetylacetone was recorded by a pulsed jet FTMW spectrometer in the spectral range between 6 and 18 GHz. Only the enol tautomer was observed. The spectrum displayed no doubling of rotational lines, indicating high barriers to internal motions. The rs structure was determined from the ground-state rotational constants of nine isotopic species (parent, five 13 C, two D and D2). The diketo form is higher in energy by 14 kJ mol-1 as predicted by MP2/6-311++G(d,p) calculations. Evangelisti L, Tang S, Velino B, Giuliano BM, Melandri S, Caminati W. (2009) Hexafluoroacetylacetone: A 'rigid' molecule with an enolic Cs shape. Chem Phys Lett 473(4-6):247-250

605 CAS RN: 138495-42-8 MGD RN: 352864 MW augmented by ab initio calculations

1,1,1,2,2,3,4,5,5,5-Decafluoropentane 2H,3H-Perfluoropentane C5H2F10 C1

510

7 Molecules with Five Carbon Atoms F

Dihedral angles C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5)

F

F

τs [deg] a 11.74 1.04 b

F

F

b

F

F

F

F

F

Copyright 2016 with permission from Elsevier.

a b

Uncertainties were not given in the original paper. Deviation from 180°.

RR

SS

The rotational spectrum of the racemic mixture of 2H,3H-perfluoropentane was recorded by chirped-pulse and Balle-Flygare FTMW spectrometers in the frequency region between 5 and 15 GHz. From the four possible enantiomers, only one pair (R,R)/(S,S) was observed. The Kraitchman Cartesian coordinates of the carbon atoms were determined from the ground-state rotational constants of six isotopic species (main and five 13C). Two derived dihedral angles of the helical carbon chain are presented. Duong CH, Obenchain DA, Cooke SA, Novick SE (2016) Rotational spectroscopy of 2H,3H-perfluoropentane. J Mol Spectrosc 324(6):53-55

606 CAS RN: MGD RN: 430350 MW supported by ab initio calculations

2,3-Difluoropyridine - argon (1/1) C5H3ArF2N C1 F

Ar

Distance Rcm b

r0 [Å] a 3.534

Angles Ar…X…N c

θ0 [deg] a

γd φe

81.4 10.0 84.9

Reprinted with permission. Copyright 2014 American Chemical Society. a

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of the difluoropyridine subunit. c X is the center-of-mass of the difluoropyridine subunit. d Angle between Rcm and the c axis of the difluoropyridine subunit. e Angle between the Ar…X…N and the ring plane. b

N

F

7 Molecules with Five Carbon Atoms

511

The rotational spectra of the binary van der Waals complex of 2,3-difluoropyridine with argon were recorded in a supersonic jet by chirped-pulse and Balle-Flygare FTMW spectrometers in the frequency region between 4 and 26 GHz. Only one isotopic species was studied. The partial r0 structure of the complex was determined under the assumption that the structural parameters of the difluoropyridine subunit were not changed upon complexation. Sun M, Kamaee M, van Wijngaarden J (2014) Microwave spectroscopic investigation and structural determination of the Ar-difluoropyridine van der Waals complexes. J Phys Chem A 118(38):8730-8736

607 CAS RN: MGD RN: 430164 MW supported by ab initio calculations

Distance Rcm b

2,4-Difluoropyridine – argon (1/1)

F

Ar

r0 [Å] a 3.535 N

Angles Ar…X…N c

γd φe

C5H3ArF2N C1

F

θ0 [deg] a 81.0 9.6 86.6

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of the difluoropyridine subunit. c X is the center-of-mass of the difluoropyridine subunit. d Angle between Rcm and the c axis in the difluoropyridine subunit. e Angle between the Ar…X…N and ring planes. b

The rotational spectra of the binary van der Waals complex of 2,4-difluoropyridine with argon were recorded in a supersonic jet by chirped-pulse and Balle-Flygare FTMW spectrometers in the frequency region between 4 and 26 GHz. Only one isotopic species was studied. The partial r0 structure of the complex was determined under the assumption that the structural parameters of the difluoropyridine subunit were not changed upon complexation. Sun M, Kamaee M, van Wijngaarden J (2014) Microwave spectroscopic investigation and structural determination of the Ar-difluoropyridine van der Waals complexes. J Phys Chem A 118(38):8730-8736

608 CAS RN: MGD RN: 429990 MW supported by ab initio calculations

2,5-Difluoropyridine – argon (1/1) C5H3ArF2N C1

F

Ar

a

Distance Rcm b

r0 [Å] 3.505

Angles

θ0 [deg] a

N

F

512

Ar…X…N c

γd φe

7 Molecules with Five Carbon Atoms

81.7 8.4 88.6

Reprinted with permission. Copyright 2014 American Chemical Society. a

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of the difluoropyridine subunit. c X is the center-of-mass of the difluoropyridine subunit. d Angle between Rcm and the c axis in the difluoropyridine subunit. e Angle between the Ar…X…N and ring planes. b

The rotational spectra of the binary van der Waals complex of 2,5-difluoropyridine with argon were recorded in a supersonic jet by chirped-pulse and Balle-Flygare FTMW spectrometers in the frequency region between 4 and 26 GHz. Only one isotopic species was studied. The partial r0 structure of the complex was determined under the assumption that the structural parameters of the difluoropyridine subunit were not changed upon complexation. Sun M, Kamaee M, van Wijngaarden J (2014) Microwave spectroscopic investigation and structural determination of the Ar-difluoropyridine van der Waals complexes. J Phys Chem A 118(38):8730-8736

609 CAS RN: MGD RN: 429811 MW supported by ab initio calculations

2,6-Difluoropyridine – argon (1/1) C5H3ArF2N Cs Ar

Distance Rcm b

r0 [Å] a 3.486

Angles Ar…X…N c

θ0 [deg] a

γd φe

F

N

F

94.9 4.9 90

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of the difluoropyridine subunit. c X is the center-of-mass of the difluoropyridine subunit. d Angle between Rcm and the c axis in difluoropyridine subunit. e Angle between the Ar…X…N and ring planes. b

The rotational spectra of the binary van der Waals complex of 2,6-difluoropyridine with argon were recorded in a supersonic jet by chirped-pulse and Balle-Flygare FTMW spectrometers in the frequency region between 4 and 26 GHz. Only one isotopic species was studied. The partial r0 structure of the complex was determined under the assumption that the structural parameters of the difluoropyridine subunit were not changed upon complexation. Sun M, Kamaee M, van Wijngaarden J (2014) Microwave spectroscopic investigation and structural determination of the Ar-difluoropyridine van der Waals complexes. J Phys Chem A 118(38):8730-8736

7 Molecules with Five Carbon Atoms

513

610 CAS RN: MGD RN: 429626 MW supported by ab initio calculations

3,5-Difluoropyridine – argon (1/1)

F

C5H3ArF2N Cs F

Ar

Distance Rcm b

r0 [Å] a 3.545

Angles Ar…X…N c

θ0 [deg] a

γd φe

N

80.1 9.9 90

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of the difluoropyridine subunit. c X is the center-of-mass of the difluoropyridine subunit. d Angle between Rcm and the c axis in difluoropyridine subunit. e Angle between the Ar…X…N and ring planes. b

The rotational spectra of the binary van der Waals complex of 3,5-difluoropyridine with argon were recorded in a supersonic jet by chirped-pulse and Balle-Flygare FTMW spectrometers in the frequency region between 4 and 26 GHz. Only one isotopic species was studied. The partial r0 structure of the complex was determined under the assumption that the structural parameters of the difluoropyridine subunit were not changed upon complexation. Sun M, Kamaee M, van Wijngaarden J (2014) Microwave spectroscopic investigation and structural determination of the Ar-difluoropyridine van der Waals complexes. J Phys Chem A 118(38):8730-8736

611 CAS RN: 1513-66-2 MGD RN: 329688 MW augmented by ab initio calculations

2,3-Difluoropyridine C5H3F2N Cs F

Bonds N–C(2) C(2)–C(3) C(3)–C(4) C(4)−C(5) C(5)–C(6) C(6)–N

r0 [Å] a 1.307(3) 1.391(2) 1.380(2) 1.399(2) 1.394(4) 1.346(3)

rs [Å] a 1.300(4) 1.381(3) 1.373(4) 1.403(2) 1.386(3) 1.349(2)

Bond angles N–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–N C(6)–N–C(2)

θ0 [deg] a

θs [deg] a

124.43(15) 118.93(19) 117.71(12) 118.67(12) 123.03(14) 117.23(12)

124.7(5) 119.3(4) 117.3(4) 118.7(3) 123.0(4) 116.9(5)

N

F

514

7 Molecules with Five Carbon Atoms

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5 and 23 GHz. The r0 and rs structures of the ring skeleton were determined from the ground-state rotational constants of seven isotopic species (main, five 13C and 15N). The structural parameters involving the hydrogen and fluorine atoms were assumed at the values from MP2/6-311++G(2d,2p) calculations. van Dijk CW, Sun M, van Wijngaarden J (2012) Investigation of structural trends in difluoropyridine rings using chirped-pulse Fourier transform microwave spectroscopy and ab initio calculations. J Mol Spectrosc 280:34-41

612 CAS RN: 34941-90-7 MGD RN: 329500 MW augmented by ab initio calculations

2,4-Difluoropyridine C5H3F2N Cs

F

Bonds N–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–N

r0 [Å] a 1.31(3) 1.384(19) 1.385(11) 1.389(12) 1.38(3) 1.36(3)

rs [Å] a 1.299(6) 1.389(12) 1.389(12) 1.378(7) 1.38(2) 1.358(19)

Bond angles N–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–N C(6)–N–C(2)

θ0 [deg] a

θs [deg] a

127.0(4) 114.8(3) 121.7(8) 116.8(6) 123.9(2) 115.8(5)

N

F

127.5(14) 114.0(11) 122.1(12) 116.8(17) 124(2) 115.7(17)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5 and 23 GHz. The r0 and rs structures of the ring skeleton were determined from the ground-state rotational constants of seven isotopic species (main, five 13C and 15N). The structural parameters involving the hydrogen and fluorine atoms were assumed at the values from MP2/6-311++G(2d,2p) calculations. van Dijk CW, Sun M, van Wijngaarden J (2012) Investigation of structural trends in difluoropyridine rings using chirped-pulse Fourier transform microwave spectroscopy and ab initio calculations. J Mol Spectrosc 280:34-41

613

2,5-Difluoropyridine

7 Molecules with Five Carbon Atoms

515

CAS RN: 84476-99-3 MGD RN: 330085 MW augmented by ab initio calculations

C5H3F2N Cs

Bonds N–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–N

r0 [Å] a 1.310(2) 1.398(2) 1.382(3) 1.389(2) 1.388(2) 1.335(2)

rs [Å] a 1.308(2) 1.396(2) 1.378(3) 1.389(2) 1.387(2) 1.331(3)

Bond angles N–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–N C(6)–N–C(2)

θ0 [deg] a

θs [deg] a

126.06(15) 116.92(14) 117.52(12) 120.91(15) 121.51(13) 117.08(12)

F

N

F

126.0(3) 117.0(3) 117.6(3) 120.7(2) 121.6(3) 117.1(3)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5 and 23 GHz. The r0 and rs structures of the ring skeleton were determined from the ground-state rotational constants of seven isotopic species (main, five 13C and 15N). The structural parameters involving the hydrogen and fluorine atoms were assumed at the values from MP2/6-311++G(2d,2p) calculations. van Dijk CW, Sun M, van Wijngaarden J (2012) Investigation of structural trends in difluoropyridine rings using chirped-pulse Fourier transform microwave spectroscopy and ab initio calculations. J Mol Spectrosc 280:34-41

614 CAS RN: 1513-65-1 MGD RN: 577950 MW augmented by ab initio calculations

2,6-Difluoropyridine C5H3F2N C2v

Bonds N–C(2) C(2)–C(3) C(3)−C(4)

r0 [Å] a 1.3102(7) 1.3922(13) 1.3915(11)

rs [Å] a 1.319(4) 1.375(7) 1.394(2)

Bond angles N–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(6)–N–C(2)

θ0 [deg] a

θs [deg] a

125.98(15) 116.13(12) 119.95(13) 115.8(2)

Copyright 2012 with permission from Elsevier.

126.7(7) 116.2(6) 119.7(2) 114.6(6)

F

N

F

516 a

7 Molecules with Five Carbon Atoms

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5 and 23 GHz. The r0 and rs structures of the ring skeleton were determined from the ground-state rotational constants of five isotopic species (main, three 13C and 15N). The structural parameters involving the hydrogen and fluorine atoms were assumed at the values from MP2/6-311++G(2d,2p) calculations. van Dijk CW, Sun M, van Wijngaarden J (2012) Investigation of structural trends in difluoropyridine rings using chirped-pulse Fourier transform microwave spectroscopy and ab initio calculations. J Mol Spectrosc 280:34-41

615 CAS RN: 71902-33-5 MGD RN: 352526 MW augmented by ab initio calculations

3,5-Difluoropyridine C5H3F2N C2v F

F

Bonds N–C(2) C(2)–C(3) C(3)–C(4)

r0 [Å] a 1.339(4) 1.386(3) 1.396(4)

rs [Å] a 1.338(1) 1.377(6) 1.387(3)

Bond angles N–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(6)–N–C(2)

θ0 [deg] a

θs [deg] a

121.5(2) 121.6(3) 115.2(2) 118.5(2)

N

121.5(6) 122.1(5) 114.5(4) 118.4(2)

Copyright 2012 with permission from Elsevier. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 5 and 23 GHz. The r0 and rs structures of the ring skeleton were determined from the ground-state rotational constants of five isotopic species (main, three 13C and 15N). The structural parameters involving the hydrogen and fluorine atoms were assumed at the values from MP2/6-311++G(2d,2p) calculations. van Dijk CW, Sun M, van Wijngaarden J (2012) Investigation of structural trends in difluoropyridine rings using chirped-pulse Fourier transform microwave spectroscopy and ab initio calculations. J Mol Spectrosc 280:34-41

616 CAS RN: 359-98-8 MGD RN: 372248 GED augmented by QC computations

Bonds C–H

1,3,3,4,4-Pentafluoro-2-methoxycyclobutene C5H3F5O Cs (syn) Cs (anti)

F

rg [Å] a,b syn anti 1.101(17) d 1.121(17) d c

O

F

F F

F

CH3

7 Molecules with Five Carbon Atoms

C=C C(1)–C(4) C(2)–C(3) C(3)–C(4) C(3)–F(7) C(4)–F(9) C(1)–O(5) C(2)–F(6) O(5)–C(11) Angles C(4)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(1) C(2)–C(1)–O(5) C(1)–C(2)–F(6) C(1)–O(5)–C(11) F(9)–C(4)–F(10) F(7)–C(3)–F(8) F(9)–C(4)–C(1) F(7)–C(3)–C(2) H−C−H X…C(3)–C(4) f X…C(4)–C(3) f Other angle tilt(CH3) g

1.329(36) 1.501(19) 1 1.487(19) 1 1.581(21) 1.349(10) 2 1.344(10) 2 1.337(26) 3 1.346(12) 3 1.469(37)

c

1.328(36) 1.504(19) 1.485(19) 1.578(21) 1.349(10) 1.350(10) 1.343(26) 1.339(12) 1.493(37)

syn

θα [deg] a,b

syn 93.3(8) 4 96.4(8) 4 84.4(8) 85.0(9) 141.0(14) 5 135.4(14) 5 117.3(33) 108.3(13) 6 107.7(13) 6 116.6(10) 117.5(10) 110.1 d,e 134.2(15) 7 134.4(15) 7

syn -3.0 e

517

anti 93.1(8) 96.6(8) 84.4(8) 85.9(9) 135.2(14) 135.1(14) 117.8(33) 107.7(13) 107.6(13) 116.7(10) 117.6(10) 110.1 d,e 133.9(15) 134.4(15)

τα [deg] anti -3.0 e

anti

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2σ values and the estimated error due to correlation among the data. For the anti conformer, uncertainties were assumed to be equal to those of the syn conformer. b Differences between related parameters of the conformers were restrained to the values from B3LYP/cc-pVTZ computation. c Parameters with equal superscripts were refined in one group; difference between parameters in each group was restrained to the value from computation as indicated above. d Average value. e Adopted from computations at the level of theory as indicated above. f X…C is the vector bisecting the adjacent F−C−F angle. g Tilt angle between the C3 axis of the methyl group and the C(11)–O(5) bond; it is negative when the symmetry equivalent pair of H atoms move away from the double bond. The GED experiment was carried out at Tnozzle = 298 K. The title compound was found to exist as a mixture of two conformers, syn and anti, characterized by the synperiplanar and antiperiplanar C−O−C=C dihedral angles, respectively. The refined ratio of the conformers syn : anti = 71(22) : 29(22) (in %) agrees well with theoretical predictions. Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. The C(3)–C(4) bond was found to be slightly shorter than unusual long C–C single bond (opposite to the double C=C bond) in hexafluorocyclobutene and longer than in 1,2-dimetoxy-3,3,4,4-tetrafluorocyclobut-1-ene.

518

7 Molecules with Five Carbon Atoms

Frogner M, Hedberg K, Hedberg L, Lunelli B (2010) Molecular structure and conformations of 1-methoxy2,3,3,4,4-pentafluorocyclobut-1-ene. J Mol Struct 978 (1-3):294-298

617 CAS RN: MGD RN: 392259 MW supported by ab initio calculations

2-Fluoropyridine – argon (1/1) C5H4ArF C1 Ar

a

Distance Rcm b

r0 [Å] 3.522

Angles

θ0 [deg] a

c

γ ϕd φe

N

F

8.0 84.1 84.6

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of the fluoropyridine subunit. c Angle between Rcm and the c axis of the complex. d Angle between Rcm and the b axis of the complex. e Angle between the Ar…X…N and X…N…C(5) planes, where X is the center-of-mass of the fluoropyridine subunit. b

The rotational spectrum of the binary van der Waals complex of 2-fluoropyridine with argon was recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 8 and 14 GHz. The partial r0 structure was determined from the ground-state rotational constants of one isotopic species under the assumption that the structural parameters of the 2-fluoropyridine subunit were not changed upon complexation. Sun M, Kamaee M, van Wijngaarden J (2013) Rotational spectra and structures of the van der Waals dimers of argon with 2-fluoropyridine and 3-fluoropyridine. J Phys Chem A 117(50):13429-13434

618 CAS RN: MGD RN: 392051 MW supported by ab initio calculations

3-Fluoropyridine – argon (1/1) C5H4ArF C1 F Ar a

Distance Rcm b

r0 [Å] 3.564

Angles

θ0 [deg] a

c

γ ϕd φe

10.9 79.2 88.5

N

7 Molecules with Five Carbon Atoms

519

Reprinted with permission. Copyright 2013 American Chemical Society. a

Uncertainties were not given in the original paper. Distance between Ar and center-of-mass of the fluoropyridine subunit. c Angle between Rcm and the c axis of the complex. d Angle between Rcm and the b axis of complex. e Angle between the Ar…X…N and cm…N…C(5) planes, plane, where X is the center-of-mass of the fluoropyridine subunit. b

The rotational spectrum of the binary van der Waals complex of 3-fluoropyridine with argon was recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 8 and 14 GHz. The partial r0 structure was determined from the ground-state rotational constants of one isotopic species under the assumption that the structural parameters of the 3-fluoropyridine subunit were not changed upon complexation. Sun M, Kamaee M, van Wijngaarden J (2013) Rotational spectra and structures of the van der Waals dimers of argon with 2-fluoropyridine and 3-fluoropyridine. J Phys Chem A 117(50):13429-13434

619 CAS RN: 4214-79-3 MGD RN: 532285 MW augmented by DFT calculations

Bond C–Cl

r0 [Å]a 1.694(1)

Bond angle C–N–C

θ0 [deg] a

5-Chloro-2(1H)-pyridinone Cl

C5H4ClNO Cs

N H

O

127.43(5)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of 5-chloro-2-hydroxypyridine was recorded by an FTMW spectrometer in the frequency range from 4 to 18 GHz and by a free-jet absorption millimeter wave spectrometer in the range from 59 to 75 GHz. Two tautomers, the predominant lactim and the less abundant lactam forms, were identified. The partial r0 structure of the lactam was determined from the ground-state rotational constants of the main isotopic species; the remaining structural parameters were fixed at the values from B3LYP/aug-cc-pVTZ calculations. Calabrese C, Maris A, Uriarte I, Cocinero EJ, Melandri S (2017) Effects of chlorination on the tautomeric equilibrium of 2-hydroxypyridine: Experiment and theory. Chem Eur J 23(15):3595-3604

620 CAS RN: MGD RN: 533036

5-Chloro-2-pyridinol 5-Chloro-2-hydroxypyridine C5H4ClNO

520

7 Molecules with Five Carbon Atoms

MW augmented by DFT calculations

Bond C–Cl

r0 [Å]a 1.7198(6)

Bond angle C–N–C

θ0 [deg] a

Cs

Cl

N

OH

118.47(2)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of 5-chloro-2-hydroxypyridine was recorded by an FTMW spectrometer in the frequency range from 4 to 18 GHz and by a free-jet absorption millimeter wave spectrometer in the range from 59 to 75 GHz. Two tautomers, the predominant lactim and the less abundant lactam forms, were identified. The partial r0 structure of the lactim with the synperiplanar N–C–O–H moiety was determined from the groundstate rotational constants of four isotopic species (main, 37Cl, D and 37Cl/D); the remaining structural parameters were fixed at the values from B3LYP/aug-cc-pVTZ calculations. Calabrese C, Maris A, Uriarte I, Cocinero EJ, Melandri S (2017) Effects of chlorination on the tautomeric equilibrium of 2-hydroxypyridine: Experiment and theory. Chem Eur J 23(15):3595-3604

621 CAS RN: 73018-09-4 MGD RN: 533210 MW augmented by DFT calculations

Bond C–Cl

r0 [Å]a 1.7241(4)

Bond angle C–N=C

θ0 [deg] a

6-Chloro-2-pyridinol 6-Chloro-2-hydroxypyridine C5H4ClNO Cs

Cl

N

OH

117.74(3)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of 6-chloro-2-hydroxypyridine was recorded by an FTMW spectrometer in the frequency range from 4 to 18 GHz and by a free-jet absorption millimeter wave spectrometer in the range from 59 to 75 GHz. Only one tautomer, the lactim form with the synperiplanar N=C–O–H moiety, was identified. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 37 Cl, D and 37Cl/D); the values of remaining structural parameters were adopted from B3LYP/aug-cc-pVTZ calculation.

7 Molecules with Five Carbon Atoms

521

Calabrese C, Maris A, Uriarte I, Cocinero EJ, Melandri S (2017) Effects of chlorination on the tautomeric equilibrium of 2-hydroxypyridine: Experiment and theory. Chem Eur J 23(15):3595-3604

622 CAS RN: 372-48-5 MGD RN: 606499 MW augmented by ab initio calculations

2-Fluoropyridine C5H4FN Cs

Bonds N−C(2) C(2)−C(3) C(3)−C(4) C(4)−C(5) C(5)−C(6) C(6)−N

r0 [Å] a 1.312(4) 1.393(4) 1.385(5) 1.401(3) 1.390(3) 1.343(4)

rs [Å] a 1.310(18) 1.387(18) 1.389(11) 1.40(4) 1.39(4) 1.345(6)

Bond angles N−C(2)−C(3) C(2)−C(3)−C(4) C(3)−C(4)−C(5) C(4)−C(5)−C(6) C(5)−C(6)−N C(6)−N−C(2)

θ0 [deg] a

θs [deg] a

126.4(1) 116.5(2) 119.1(1) 118.3(1) 123.4(1) 116.2(1)

N

F

127(2) 116.5(16) 119(4) 118(4) 123(4) 116.0(15)

Reprinted with permission. Copyright 2012 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of 2-fluoropyridine were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 8 and 23 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 15N and five 13C); the structural parameters involving H and F were assumed at the values from MP2/6311++G(2d,2p) calculations. The rs structure was also obtained for the ring skeleton. van Dijk CW, Sun M, van Wijngaarden J (2012) Microwave rotational spectra and structures of 2-fluoropyridine and 3-fluoropyridine. J Phys Chem A 116(16):4082-4088

623 CAS RN: 372-47-4 MGD RN: 240370 MW augmented by ab initio calculations

Bonds N–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–N

3-Fluoropyridine C5H4FN Cs

F

r0 [Å] a 1.336(7) 1.388(5) 1.384(4) 1.395(7) 1.394(4) 1.343(6)

rs [Å] a 1.336(13) 1.38(2) 1.38(2) 1.395(8) 1.39(2) 1.34(2)

N

522

Bond angles N–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–N C(6)–N–C(2)

7 Molecules with Five Carbon Atoms

θ0 [deg] a 121.8(2) 121.4(2) 116.6(3) 119.0(1) 123.5(1) 117.6(2)

θs [deg] a

122(2) 122(2) 116.4(17) 119.1(19) 123(2) 118(2)

Reprinted with permission. Copyright 2012 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of 3-fluoropyridine were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 8 and 23 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 15N and five 13C); the structural parameters involving H and F were assumed at the values from MP2/6311++G(2d,2p) calculations. The rs structure was also obtained for the ring skeleton. van Dijk CW, Sun M, van Wijngaarden J (2012) Microwave rotational spectra and structures of 2-fluoropyridine and 3-fluoropyridine. J Phys Chem A 116(16):4082-4088 624 CAS RN: 13177-38-3 MGD RN: 375804 MW augmented by ab initio calculations

2,4-Cyclopentadien-1-one C5H4O C2v O a

Bonds C(1)=O C(1)–C(2) C(2)=C(3) C(3)–C(3ꞌ) C(2)–H C(3)–H

r [Å] 1.208(1) 1.502(1) 1.338(1) 1.496(1) 1.077(1) 1.079(1)

Bond angles O=C(1)–C(2) C(1)–C(2)=C(3) C(1)–C(2)–H C(2)–C(3)–H

θ see [deg] a

se e

127.0(1) 107.4(1) 123.7(1) 126.8(1)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of cyclopentadienone were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 7.5 and 18.5 GHz. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants of eight isotopic species (main, D4, three 13C and three 13C/D4) taking into account rovibrational corrections calculated from the CCSD(T)/ANO0 harmonic and anharmonic (cubic) force fields.

7 Molecules with Five Carbon Atoms

523

Kidwell NM, Vaquero-Vara V, Ormond TK, Buckingham GT, Zhang D, Mehta-Hurt DN, McCaslin L, Nimlos MR, Daily JW, Dian BC, Stanton JF, Ellison GB, Zwier TS (2014) Chirped-pulse Fourier transform microwave spectroscopy coupled with a flash pyrolysis microreactor: structural determination of the reactive intermediate cyclopentadienone. J Phys Chem Lett 5(13):2201-2207

625 CAS RN: 276256-93-0 MGD RN: 145328 IR supported by ab initio calculations

Ethyne – carbonyl sulfide (2/1) C5H4OS Cs O

Distances cm(1)…cm(2) b cm(1)…cm(3) b

r0 [Å] a 4.149 5.263

Angles O(4)...cm(1)...cm(2) b cm(1)...cm(2)...H(5) b O(4)...cm(1)...cm(3) b cm(1)...cm(3)...H(6) b

θ0 [deg] a

C

S

H

C

C

H

2

63.0 77.0 17.0 150.9

Copyright 2011 with permission from Elsevier.

a

Uncertainties were not given in the original paper. cm(1) is the center-of-mass of the OCS subunit, whereas cm(2) and cm(3) are centers of mass of the HCCH(5) and HCCH(6) subunits, respectively. b

The rotationally resolved IR spectrum of the ternary complex was recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the region of the OCS ν1 fundamental band at 2065 cm-1. The spectrum was assigned to the planar conformer, although a barrel-type conformer was previously identified in the MW spectrum. The r0 structure of the planar conformer was determined from the ground-state rotational constants of three isotopic species (16O12C32S ‧ (HCCH)2, 16O12C32S ‧ (DCCD)2 and 18O12C32S ‧ (DCCD)2) under the assumption that the structures of the monomer subunits were not changed upon complexation. Norooz Oliaee J, McKellar ARW, Moazzen-Ahmadi N (2011) Observation of a planar isomer of the OCS(C2H2)2 trimer. Chem Phys Lett 512(4-6):167-171

626 CAS RN: 1261509-41-4 MGD RN: 212984 MW augmented by ab initio calculations

Pyridine – argon – neon (1/1/1) C5H5ArNNe Cs Ar

Distances Rcm1 b Rcm2 c

r0 [Å] a 3.540(3) 3.396(4)

Angles

θ0 [deg] a

Ne

N

524

φ1 d φ2 e

7 Molecules with Five Carbon Atoms

87.8(14) 85.4(14)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Distance between Ar and the center-of-mass of the pyridine subunit. c Distance between Ne and the center-of-mass of the pyridine subunit. d Angle between Rcm1 and the ring plane. e Angle between Rcm2 and the ring plane. b

The rotational spectrum of the mixed van der Waals complex was recorded by a pulsed-jet Balle-Flygare-type FTMW spectrometer in the frequency range between 6.5 and 18 GHz. Only one conformer, with the Ne and Ar atoms lying above and below the ring plane, was detected. The MP2/6-311++G** calculations predicted several almost equivalent minima on the PES, separated by very low barriers. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 22Ne, 15N and 15N/22Ne); the remaining structural parameters were fixed to the values from MP2/6-311++G** calculations. Melandri S, Giuliano BM, Maris A, Evangelisti L, Velino B, Caminati W (2009) Rotational spectrum of the mixed van der Waals triad pyridine-Ar-Ne. ChemPhysChem 10(14):2503-2507

627 CAS RN: 1173885-09-0 MGD RN: 211490 MW augmented by QC calculations

(η5-2,4-Cyclopentadien-1-yl)thallium - argon (1/1) C5H5ArTl C5v

Tl

Ar

Distances Rcm b Ar…Tl

r0 [Å] a 3.56 5.97

Reproduced with permission of AIP Publishing. a b

Uncertainties were not given in the original paper. Distance between Ar and the center-of-mass of the C5H5 subunit.

The rotational spectra of the binary van der Waals complex of cyclopentadienyl thallium with argon were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 4 and 9 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 203Tl) under the assumption that the structural parameters of cyclopentadienyl were not changed upon complexation. Tanjaroon C, Daly AM, Kukolich SG (2008) The rotational spectrum and structure for the argoncyclopentadienyl thallium van der Waals complex: Experimental and computational studies of noncovalent bonding in an organometallic π-complex. J Chem Phys 129(5):054305/1-054305/8 https://doi.org/10.1063/1.2955739 628 CAS RN: 1454620-67-7

2-Propenoic acid – 2,2,2-trifluoroacetic acid (1/1) Acrylic acid – trifluoroacetic acid (1/1)

7 Molecules with Five Carbon Atoms

525

C5H5F3O4 Cs

MGD RN: 259553 MW supported by ab initio calculations

O

O

Distances Rcm b

s- cis r0 [Å] a 5.24

H 2C

s-trans r0 [Å] a 5.27

F OH

OH F

F

Reprinted with permission. Copyright 2013 American Chemical Society. a b

Uncertainty was not given in the original paper. Distance between the centers of mass of the monomer subunits.

s-cis

s-trans

The rotational spectra of the binary complex of acrylic acid with trifluoroacetic acid were investigated in a supersonic jet by an FTMW spectrometer in the frequency region between 6.5 and 18 GHz. According to relative intensity measurements, the s-cis conformer is more stable than the s-trans one. The partial r0 structure of each conformer was determined from the ground-state rotational constants of four isotopic species (main, two D and D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The deuteration of the carboxylic groups leads to an increase of the distance between the two subunits (Ubbelohde effect). Gou Q, Feng G, Evangelisti L, Caminati W (2013) Rotational study of cis- and trans-acrylic acid-trifluoroacetic acid. J Phys Chem A 117(50):13500-13503 629 CAS RN: 110-86-1 MGD RN: 183542 MW augmented by ab initio calculations

Pyridine C 5H 5N C2v

Bonds N−C(2) C(2)−C(3) C(3)−C(4)

r0 [Å] a 1.340(5) 1.397(6) 1.394(6)

rs [Å] a 1.340(2) 1.390(3) 1.394(2)

Bond angles N−C(2)−C(3) C(2)−C(3)−C(4) C(3)−C(4)−C(5) C(6)−N−C(2)

θ0 [deg] a

θs [deg] a

123.7(5) 118.5(6) 118.5(6) 117.1(5)

123.8(3) 118.6(3) 118.3(2) 116.8(2)

Copyright 2012 with permission from Elsevier [a]. a

Parenthesized uncertainties in units of the last significant digit.

N

526

7 Molecules with Five Carbon Atoms

The r0 and rs structures of the ring skeleton were determined using the previously published ground-state rotational constants. The structural parameters involving hydrogen atoms were assumed at the values from MP2/6-311++G(2d,2p) calculations. a. van Dijk CW, Sun M, van Wijngaarden J (2012) Investigation of structural trends in difluoropyridine rings using chirped-pulse Fourier transform microwave spectroscopy and ab initio calculations. J Mol Spectrosc 280:34-41 MW augmented by DFT calculations

C2v

Bonds N–C(2) C(2)–C(3) C(3)–C(4) C(2)–H C(3)–H C(4)–H

r (m2) [Å] a

1.3368(8) 1.3915(13) 1.3906(7) 1.0839(6) 1.0800(6) 1.0805(5)

r e [Å] a 1.3362(5) 1.3902(4) 1.3890(4) 1.0816(4) 1.0795(4) 1.0803(4)

Bond angles C(3)–C(4)–H C(3)–C(4)–C(5) C(4)–C(3)–H C(2)–C(3)–C(4) C(2)–C(3)–H C(3)–C(2)–H N–C(2)–C(3) N–C(2)–H C(2)–N–C(6)

θ (m2) [deg] a

θ see [deg] a

120.78(3) 118.44(6) 121.27(6) 118.51(6) 120.22(7) 120.31(7) 123.78(6) 115.91(6) 116.97(6)

se

120.71(2) 118.42(4) 121.34(5) 118.54(4) 120.11(6) 120.30(6) 123.80(4) 115.90(5) 116.90(4)

Reprinted with permission. Copyright 2014 American Chemical Society [b]. a

Parenthesized uncertainties in units of the last significant digit.

The mass-dependent structure r (m2) was determined from the previously published ground-state rotational se

constants of ten isotopic species. The semiexperimental equilibrium structure r e was obtained by taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the B3LYP/6-311+G(3df,2pd) harmonic and anharmonic (cubic) force fields. b. Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and sevenmembered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746

630 CAS RN: 1151792-07-2 MGD RN: 212382 MW

Pyridine – neon (1/2) C5H5NNe2 C2v 2Ne

Distance Rcm b

r0 [Å] a 3.391(1)

rs [Å] d 3.355

N

7 Molecules with Five Carbon Atoms

Angle

ϕ

c

θ0 [deg] a 87.2(2)

527

θs [deg] d 85.8

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit. Distance between Ne and the center-of-mass of the pyridine subunit. c Angle between Rcm and the ring plane towards N. d Uncertainty was not given in the original paper. b

The rotational spectrum of the ternary van der Waals complex of pyridine with neon was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 18 GHz. Only one conformer with C2v symmetry (the Ne atoms located on the different sides of the ring plane) was detected. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, 15N, 22Ne, 22Ne2, 15N/22Ne and 15N/22Ne) under the assumption that the structural parameters of the pyridine subunit were not changed upon complexation. Evangelisti L, Favero LB, Giuliano BM, Tang S, Melandri S, Caminati W (2009) Microwave spectrum of [1,1]pyridine-Ne2. J Phys Chem A 113:14227-14230

631 CAS RN: 1121-30-8 MGD RN: 333419 MW augmented by ab initio calculations

1-Hydroxy-2(1H)-pyridinethione C5H5NOS Cs

Bonds O–H C(2)=S

r0 [Å] a 0.93(2) 1.66(2)

Bond angles N–O–H C(5)…C(2)=S

θ0 [deg] a

N

S

OH

105(4) 173.0(5)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

When 2-mercaptopyridine N-oxide was evaporated into the cavity of a pulsed-jet FTMW spectrometer, only rotational transitions of the 1-hydroxy-2(1H)-pyridinethione tautomer were observed in the frequency range between 6 and 18 GHz. The 34S isotopic species was studied in natural abundance, whereas the hydroxyldeuterated species was investigated in an enriched sample. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species; the remaining structural parameters were fixed at the values from MP2/6-31+G(d,p) calculations. The title molecule is stabilized by an intramolecular hydrogen bond.

528

7 Molecules with Five Carbon Atoms

Daly AM, Mitchell EG, Sanchez DA, Block E., Kukolich SG (2011) Microwave spectra and gas phase structural parameters for N-hydroxypyridine-2(1H)-thione. J Phys Chem A 115(50):14526-14530

632 CAS RN: MGD RN: 487525 MW supported by DFT calculations

Distances H(1)…O(1) O(2)…H(2) Rcm b

1H-Pyrrole-2,5-dione – formic acid (1/1) Maleimide – formic acid (1/1) C5H5NO4

Cs

O O

r0 [Å] a 2.027 1.634 4.06

N H

O H

OH

Copyright 2016 with permission from Elsevier. a b

Uncertainties were not given in the original paper. Center-of-mass separation between the monomer subunits.

The rotational spectrum of the binary complex of maleimide with formic acid was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 4.9 and 10 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main and three D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The rotational constants were found to be consistent with a planar structure. Pejlovas AM, Kukolich SG (2016) Rotational spectra and gas phase structure of the maleimide – formic acid doubly hydrogen bonded dimer. J Mol Spectrosc 321(3):1-4

633 CAS RN: 98-96-4 MGD RN: 539839 GED augmented by QC computations

Pyrazinamide Pyrazinecarboxamide C5H5N3O Cs O N NH2

Distances C(1)–N(2) C(1)–C(6) C(1)–C(7) N(2)–C(3) C(3)–C(4) C(3)–H C(4)–N(5) C(4)–H N(5)–C(6) C(6)–H C(7)–N(8) C(7)=O N(8)–H(1) N(8)–H(2) N(2)...H(1) O...H(3)

a

r [Å] 1.341(3) 1.404(2) 1.493(1) 1.333(3) 1.390(2) 1.082(8) 1.326(3) 1.082(8) 1.331(3) 1.080(8) 1.335(2) 1.219(1) 1.002(7) 1.001(6) 2.249(7) b 2.540(9) b se e

N

7 Molecules with Five Carbon Atoms

Bond angles N(2)–C(1)–C(6) N(2)–C(1)–C(7) C(1)–N(2)–C(3) C(6)–C(1)–C(7) C(1)–C(6)–N(5) C(1)–C(6)–H C(1)–C(7)–N(8) C(1)–C(7)=O N(2)–C(3)–C(4) N(2)–C(3)–H C(4)–C(3)–H C(3)–C(4)–N(5) C(3)–C(4)–H N(5)–C(4)–H C(4)–N(5)–C(6) N(5)–C(6)–H N(8)–C(7)=O C(7)–N(8)–H(1) C(7)–N(8)–H(2) H–N(8)–H

529

θ see [deg] a

120.7(2) b 118.8(2) 116.5(2) 120.5(2) b 122.4(3) b 119.3(5) b 114.1(2) 121.0(2) 122.1(2) 117.0(4) 120.9(4) b 122.1(2) 120.7(4) 117.2(4) b 116.2(2) b 118.3(5) 124.9(2) b 119.1(22) 119.0(23) 121.8(19) b

Copyright 2016 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Dependent parameter, i.e. derived from the refined parameters.

The GED experiment was carried out at Tnozzle = 400 K. It was shown that the molecule is stabilized by intramolecular hydrogen bond and can be described by a rigid model. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP5/SVPD quadratic and cubic force constants taking into account non-linear kinematic effects. Tikhonov DS, Vishnevskiy YV, Rykov AN, Grikina OE, Khaikin LS (2017) Semi-experimental equilibrium structure of pyrazinamide from gas-phase electron diffraction. How much experimental is it? J Mol Struct 1132:20-27

634 CAS RN: 73-24-5 MGD RN: 871302 GED supported by MS and augmented by QC computations Bonds C(2)–N(1) C(2)–N(3) C(4)–N(3) C(4)–C(5) C(5)–C(6) C(6)–N(1) C(5)–N(7) C(8)=N(7) C(8)–N(9) C(4)–N(9)

a,b

r [Å] 1.344(3) 1 1.330(3) 1 1.333(3) 1 1.401(3) 2 1.409(3) 2 1.332(3) 1 1.380(4) 3 1.319(3) 1 1.371(4) 3 1.377(4) 3 se e

9H-Purin-6-amine Adenine C5H5N5 Cs (skeleton) NH2 N

N

N

N H

530

7 Molecules with Five Carbon Atoms

C(6)–N(10) C(2)–H N(9)–H C(8)–H N(10)–H(1) N(10)–H(2)

1.357(4) 3 1.075(5) 4 1.000(5) 4 1.071(5) 4 0.999(5) 4 0.999(5) 4

Bond angles N(1)–C(2)–N(3) C(2)–N(3)–C(4) N(3)–C(4)–C(5) C(4)–C(5)–N(7) C(5)–N(7)=C(8) C(5)–C(6)–N(10) N(3)–C(2)–H C(4)–N(9)–H N(7)=C(8)–H C(6)–N(10)–H(1) C(6)–N(10)–H(2) C(4)–C(5)–C(6) C(5)–C(6)–N(1) C(6)–N(1)–C(2) N(7)=C(8)–N(9) C(4)–N(9)–C(8) C(5)–C(4)–N(9) N(1)–C(6)–N(10)

θ see [deg] a,b

Dihedral angle C(4)–C(5)–C(6)–N(10)

τ see [deg]

129.0(1) 5 111.0(1) 5 127.2(1) 5 111.9(2) 6 103.4(2) 6 121.9(2) 5 116.0 c 125.9 c 124.8 c 117.1 c 116.2 c 115.2(1) d 119.6(3) d 118.0(3) d 113.5(6) d 107.0(7) d 104.1(6) d 118.5(3) d

180.0 e

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscript were refined in one group. Differences between parameters in each group were assumed at the values from MP2/cc-pVTZ computation. c Assumed at the value from computation as indicated above. d Dependent parameter. e Assumed. b

According to predictions of QC computations at the B3LYP and MP2 levels of theory (with cc-pVTZ and augcc-pVTZ basis sets), the title molecule has an essentially planar heavy-atom skeleton and the quasi-planar amino group with very low barrier to inversion (0.1 kcal mol-1 (MP2/aug-cc-pVTZ)). The GED experiments was carried out at Tnozzle = 484(15) K. In the GED analysis, the heavy-atom skeleton of the molecule was assumed to have local Cs symmetry. Positions of hydrogen atoms could not be determined due to weak electron scattering by these light atoms. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2/cc-pVTZ quadratic and cubic force constants taking into account non-linear kinematic effects. Some methodological improvements were suggested for calculations of vibrational corrections. Vogt N, Dorofeeva OV, Sipachev VA, Rykov AN (2009) Molecular structure of 9H-adenine tautomer: Gasphase electron diffraction and quantum-chemical studies. J Phys Chem A 113 (49):13816-13823

635 CAS RN: 73-40-5

2-Amino-1,7-dihydro-6H-purin-6-one Guanine

7 Molecules with Five Carbon Atoms

531

MGD RN: 209304 TRED

Bonds C(4)−N(3) C(4)−N(9) N(9)=C(8) C(8)−N(7) N(7)−C(5) C(5)−C(4) C(5)−C(6) C(6)=O C(6)−N(1) N(1)−C(2) C(2)−N(2) C(2)=N(3)

C5H5N5O O

r [Å] a,b 1.379 1.375 1.316 1.362 1.375 1.401 1.443 1.237 1.430 1.395 1.388 1.314

H N

HN

H 2N

N

N

Reprinted with permission. Copyright 2009 American Chemical Society.

a b

Uncertainties were not stated. Type of parameters was not specified.

Only one tautomer was considered in the structural analysis. A vibrational temperature of 1600 K was deduced from the best fit to the experimental intensities. The single bonds were found to be shorter than typical single-bond lengths, pointing that aromaticity is not totally lost. Gahlmann A, Park ST, Zewail AH (2009) Structure of isolated biomolecules by electron diffraction-laser desorption: Uracil and guanine. J Am Chem Soc 131 (8):2806-2808

636 CAS RN: 35634-10-7 MGD RN: 843315 IR supported by DFT calculations

Bond C(1)–C(2)

Tricyclo[1.1.1.01,3]pentane [1.1.1]Propellane C 5H 6 D3h

r0 [Å] a 1.586277(3)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainty in unit of the last significant digit.

The rotationally resolved mid-IR spectrum of [1.1.1]propellane was recorded by an FTIR spectrometer in the regions of the three fundamental bands ν10, ν11 and ν14 and two difference bands ν10-ν18 and ν11-ν18. The axial C(1)–C(2) bond was determined from the C0 rotational constant.

532

7 Molecules with Five Carbon Atoms

Kirkpatrick R, Masiello T, Martin M, Nibler JW, Maki A, Weber A, Blake TA (2012) High-resolution infrared studies of the ν10, ν11, ν14, and ν18 levels of [1.1.1]propellane. J Mol Spectrosc 281:51-62

637 CAS RN: 574758-61-5 MGD RN: 531381 MW augmented by ab initio calculations

2-Fluoropyridine – water (1/1) C5H6FNO Cs O a

Distances N(1)…O(8) N(1)…H(1) H(2)…O(8)

r0 [Å] 2.910(5) 1.988(5) b 2.877(5) b

Angles O(8)…N(1)–C(2) H(3)–O(8)…N(1) N(1)…H(1)–O(8)

θ0 [deg] a

H N

H

F

96.7(1) 116(4) 158(4) b

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of the complex was recorded by a pulsed-jet Balle-Flygare-type FTMW spectrometer in the frequency range between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 18 O, two D and D2); the remaining structural parameters were fixed to the MP2/6-311++G(d,p) values. The complex was found to be formed by the O–H(1)…N hydrogen bond and the C(2)–H…O weak hydrogen bond, where water is coplanar to the aromatic ring. The barrier to planarity of the motion of the water hydrogen not involved in the hydrogen bond was supposed to be very low (quasi-planar structure). Gou Q, Spada L, Vallejo-Lopez M, Melandri S, Lesarri A, Cocinero EJ, Caminati W (2016) Intermolecular hydrogen bonding in 2-fluoropyridine-water. ChemistrySelect 1(6):1273-1277 638 CAS RN: 731863-20-0 MGD RN: 493071 MW supported by ab initio calculations

3-Fluoropyridine – water (1/1) F

C5H6FNO Cs O H

Distance N…H

r0 [Å] a 1.9961(5)

Angle O−H…N

θ0 [deg] a 156.8(1)

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit.

N

H

7 Molecules with Five Carbon Atoms

533

The rotational spectrum of the binary complex of 3-fluoropyridine with water was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 18 O, two D and D2) under the assumption that structural parameters of the monomer subunits were not changed upon complexation. Calabrese C, Gou Q, Spada L, Maris A, Caminati W, Melandri S (2016) Effects of fluorine substitution on the microsolvation of aromatic azines: The microwave spectrum of 3-fluoropyridine-water. J Phys Chem A 120(27):5163-5168

639 CAS RN: 615-77-0 MGD RN: 413075 GED augmented by ab initio computations

1-Methyl-2,4(1H,3H)-pyrimidinedione 1-Methyluracil C5H6N2O2

Bonds N(1)–C(2) C(2)–N(3) N(3)–C(4) C(4)–C(5) N(1)–C(6) N(1)–C(7) C(2)=O(8) C(4)=O(9) C(7)–Hʹ C(7)–Hʹʹ N(3)–H C(5)–H C(6)–H C(5)=C(6)

r see [Å] a,b 1.382(1) 1 1.375(1) 1 1.394(1) 1 1.447(3) 2 1.372(1) 1 1.451(3) 2 1.210(1) 3 1.211(1) 3 1.086(4) 4 1.087(4) 4 1.009(4) 4 1.076(4) 4 1.081(4) 4 1.343(24) c

Bond angles N(1)–C(2)–N(3) C(2)–N(3)–C(4) N(3)–C(4)–C(5) C(2)–N(1)–C(6) C(2)–N(1)–C(7) N(1)–C(2)=O(8) N(3)–C(4)=O(9) N(1)–C(7)–Hʹ N(1)–C(7)–Hʹʹ N(1)–C(7)–H C(4)–C(5)–H C(5)=C(6)–H C(2)–N(3)–H C(4)–C(5)=C(6) N(1)–C(6)=C(5) C(6)–N(1)–C(7) N(3)–C(2)=O(8) C(5)–C(4)=O(9)

θ see [deg] a 114.5(5) 128.2(2) 113.1(3) 121.3(4) 116.3(6) 122.6(7) 120.3(5) 108.4 d 110.2 d 110.2 d 118.9 d 121.9 d 115.3 d 119.9(6) c 123.0(9) c 122.4(7) c 123.0(8) c 126.6(6) c

rg [Å] a 1.394(1) 1.386(1) 1.406(1) 1.458(3) 1.383(1) 1.464(3) 1.215(1) 1.216(1) 1.107(4) 1.108(4) 1.029(4) 1.097(4) 1.101(4) 1.351(24)

534

Dihedral angle C(6)–N(1)–C(7)–Hʹʹ

7 Molecules with Five Carbon Atoms

τe [deg] 120.2 d

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values of the CCSD(T)_ae/CBS structure. c Dependent parameter. d Adopted from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle = 446(3) K. The barrier to internal rotation of the methyl group around the N–C bond was predicted to be 1.2 kJ mol-1 (MP2/cc-pVTZ). Large-amplitude motion of the methyl group was considered in the GED analysis. Vibrational corrections to the experimental internuclear distances, ∆re = ra− re, were calculated from the MP2/ccpVTZ quadratic and cubic force constants taking into account non-linear kinematic effects. The equilibrium structure optimized at the CCSD(T)_ae/cc-pwCVTZ level of theory was extrapolated to CBS limit using results of MP2 computations. The computed structure was found to be in remarkable agreement with that derived from the GED data. Vogt N, Marochkin II, Rykov AN, Dorofeeva OV (2013) Interplay of experiment and theory: Determination of an accurate equilibrium structure of 1-methyluracil by the gas electron diffraction method and coupled-cluster computations. J Phys Chem A 117 (44):11374-11381

640 CAS RN: 65-71-4 MGD RN: 127415 MW augmented by ab initio calculations

5-Methyl-2,4-(1H,3H)-pyrimidinedione Thymine C5H6N2O2 O Cs CH3

HN

Bonds N(1)–C(2) C(2)–N(3) N(3)–C(4) N(1)–C(6) C(4)–C(5) C(5)=C(6) C(5)–C(9) C(2)=O(7) C(4)=O(8) N(1)–H N(3)–H C(6)–H C(9)–H(2) C(9)–H(1)

r see [Å] a 1.3782(10) 1.3797(9) 1.3932(10) 1.3709(20) b 1.4635(9) 1.3457(10) 1.4931(8) 1.2096(10) 1.2154(10) 1.0039(8) 1.0087(7) 1.0804(12) 1.0883(12) 1.0893(12)

Bond angles N(3)–C(2)–N(1) C(4)–N(3)–C(2) C(5)–C(4)–N(3) C(6)=C(5)–C(4) O(7)–C(2)–N(1) O(8)=C(4)–N(3)

θ see [deg] a 112.77(7) 127.96(6) 114.81(6) 117.88(7) 123.39(9) 120.42(9)

O

N H

7 Molecules with Five Carbon Atoms

H–N(3)–C(2) C(2)–N(1)–H C(9)–C(5)–C(4) H–C(6)=C(5) H(1)–C(9)–C(5) H(2)–C(9)–C(5)

115.52(9) 115.24(8) 117.84(7) 122.17(12) 110.56(11) 110.77(12)

Dihedral angle C(4)–C(5)–C(9)–H(1)

τ see [deg] a

535

59.19(11)

Copyright 2014 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Dependent parameter.

The semiexperimental equilibrium structure r see of the title molecule was determined from the previously published experimental ground-state rotational constants of ten isotopic species (parent, two 15N, five 13C and two D) taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. The obtained structure was used to benchmark the accuracy of the structural determinations by different experimental methods and QC calculations (up to CCSD(T)_ae/cc-pwCVQZ level of theory). Vogt N, Demaison J, Ksenafontov DN, Rudolph HD (2014) A benchmark study of molecular structure by experimental and theoretical methods: Equilibrium structure of thymine from microwave rotational constants and coupled-cluster computations. J Mol Struct 1076:483-489

641 CAS RN: 5006-22-4 MGD RN: 944490 MW augmented by ab initio calculations

Cyclobutanecarbonyl chloride Cyclobutanecarboxylic acid chloride C5H7ClO O C1

Bonds C(1)–C(4) C(4)=O C(1)–C(2) C(1)–C(2ꞌ) C(2)–C(3) C(2ꞌ)–C(3) C(4)–Cl C(1)–H C(2)–H(1) C(2ꞌ)–H(1) C(2)–H(2) C(2ꞌ)–H(2) C(3)–H(1) C(3)–H(2)

r0 [Å] a 1.491(4) 1.193(3) 1.553(4) 1.540(4) 1.547(4) 1.546(4) 1.801(3) 1.094(2) 1.094(2) 1.093(2) 1.091(2) 1.091(2) 1.091(2) 1.093(2)

Bond angles C(1)–C(4)=O C(1)–C(4)–Cl Cl–C(4)=O

θ0 [deg] a 127.8(5) 110.8(5) 121.2(5)

Cl

536

7 Molecules with Five Carbon Atoms

C(4)–C(1)–C(2) C(4)–C(1)–C(2ꞌ) C(2)–C(1)–C(2ꞌ) C(1)–C(2)–C(3) C(1)–C(2ꞌ)–C(3ꞌ) C(2)–C(3)–C(2ꞌ) H–C(1)–C(2) H–C(1)–C(2ꞌ) H–C(1)–C(4) H(1)–C(2)–C(1) H(1)–C(2ꞌ)–C(1) H(1)–C(2)–C(3) H(1)–C(2ꞌ)–C(3) H(2)–C(2)–C(1) H(2)–C(2ꞌ)–C(1) H(2)–C(2)–C(3) H(2)–C(2ꞌ)−C(3) H(1)–C(2)–H(2) H(1)–C(2ꞌ)–H(2) H(1)–C(3)–C(2) H(1)–C(3)−C(2ꞌ) H(2)−C(3)–C(2) H(2)–C(3)–C(2ꞌ) H(1)–C(3)–H(2)

117.5(5) 119.6(5) 87.4(5) 88.0(5) 88.6(5) 87.5(5) 107.6(5) 113.7(5) 109.2(5) 110.3(5) 110.1(5) 111.4(5) 111.7(5) 117.3(5) 117.9(5) 118.4(5) 117.9(5) 109.7(5) 109.6(5) 118.1(5) 118.3(5) 110.8(5) 111.1(5) 109.5(5)

Dihedral angles C(3)–C(2)–C(2ꞌ)–C(1) H–C(1)–C(4)=O H–C(1)–C(4)–Cl

τ0 [deg] a 30.9(5) 130.0(5) 55.0(5)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of cyclobutanecarboxylic acid chloride was recorded in a supersonic jet by a BalleFlygave type FTMW spectrometer in the frequency region between 11 and 18 GHz. The spectrum was assigned to the gauche-equatorial conformer. The r0 structure was determined by adjusting the MP2_full/6-311+G(d,p) structure to the ground-state rotational constants of two isotopic species (main and 37Cl). Klaassen JJ, Darkhalil ID, Deodhar BS, Gounev TK, Gurusinghe RM, Tubergen MJ, Groner P, Durig JR (2013) Microwave and infrared spectra, adjusted r0 structural parameters, conformational stabilities, vibrational assignments, and theoretical calculations of cyclobutylcarboxylic acid chloride. J Phys Chem A 117(30):65086524

642 CAS RN: 4426-11-3 MGD RN: 344409 MW augmented by QC calculations

Bonds C(5)≡N

Cyanocyclobutane Cyclobutyl cyanide C 5H 7N Cs (equatorial) Cs (axial)

equatorial r0 [Å] a 1.160(3)

axial r0 [Å] a 1.160(3)

C

N

7 Molecules with Five Carbon Atoms

537

C(1)−C(5) C(1)−C(2) C(2)−C(3) C(1)−H C(2)−H(1) C(2)−H(2) C(3)−H(1) C(3)−H(2)

1.461(3) 1.557(3) 1.549(3) 1.094(2) 1.093(2) 1.091(2) 1.091(2) 1.094(2)

1.468(3) 1.562(3) 1.550(3) 1.092(2) 1.091(2) 1.093(2) 1.093(2) 1.091(2)

Bond angles C(1)−C(5)≡N C(2)−C(1)−C(5) C(2)−C(1)−C(4) C(3)−C(2)−C(1) C(2)−C(3)−C(4) H−C(1)−C(2) H−C(1)−C(5) H(1)−C(2)−C(1) H(1)−C(2)−C(3) H(2)−C(2)−C(1) H(2)−C(2)−C(3) H(1)−C(2)−H(2) H(1)−C(3)−C(2) H(2)−C(3)−C(2) H(1)−C(3)−H(2)

θ0 [deg] a

θ0 [deg] a

Dihedral angle C(3)−C(2)−C(4)−C(1)

τ0 [deg] a

τ0 [deg] a

178.6(5) 118.0(5) 88.3(5) 87.8(5) 88.9(5) 110.5(5) 109.8(5) 110.1(5) 107.7(5) 117.4(5) 122.0(5) 109.8(5) 119.0(5) 109.4(5) 109.5(5)

28.5(5)

179.9(5) 111.1(5) 87.9(5) 89.1(5) 88.8(5) 118.0(5) 109.3(5) 117.5(5) 121.6(5) 109.3(5) 107.5(5) 109.9(5) 108.5(5) 119.9(5) 109.4(5)

-24.1(5)

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

equatorial

axial

The enthalpy difference between the more stable equatorial conformer and the axial one was estimated to be 3.03 kJ mol-1 by temperature-dependent IR vibrational spectroscopy. The percentage of the axial conformer was estimated to be 23(1) % (at ambient temperature). The r0 structural parameters of each conformer were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of the parent species; the C–H bond lengths were assumed at ab initio values. Durig JR, Ganguly A, Klaassen JJ, Guirgis GA (2009) The r0 structural parameters, conformational stability, and vibrational assignment of equatorial and axial cyanocyclobutane. J Mol Struct 923(1-3):28-38.

538

7 Molecules with Five Carbon Atoms

643 CAS RN: 5811-25-6 MGD RN: 378726 MW augmented by ab initio calculations

Isocyanotocyclobutane Cyclobutyl isocyanate C5H7NO Cs (equatorial-anti) N C

Bonds C(4)=O N=C(4) C(1)–N C(1)–C(2) C(3)–C(2) C(1)–H(3) C(2)–H(2) C(2)–H(1) C(3)–H(4) C(3)–H(5)

r0 [Å]a 1.161(5) 1.208(5) 1.433(5) 1.548(5) 1.557(5) 1.093(2) 1.094(2) 1.092(2) 1.091(2) 1.093(5)

Bond angles N=C(4)=O C(1)–N=C(4) C(2)–C(1)–N C(2)–C(1)–C(2) C(3)–C(2)–C(1) C(2)–C(3)–C(2) H(3)–C(1)–C(2) H(3)–C(1)–N H(2)–C(2)–C(1) H(2)–C(2)–C(3) H(1)–C(2)–C(1) H(1)–C(2)–C(3) H(2)–C(2)–H(1) H(4)–C(3)–C(2) H(5)–C(3)–C(2) H(5)–C(3)–H(4)

θ0 [deg]a

O

172.0(5) 135.2(5) 119.8(5) 88.9(5) 87.2(5) 88.3(5) 110.2(5) 107.7(5) 109.8(5) 108.3(5) 118.2(5) 121.3(5) 110.0(5) 118.4(5) 110.1(5) 109.4(5)

Reproduced with permission of SNCSC

a

Parenthesized estimated uncertainties in units of the last significant digit.

Three conformers, equatorial-anti, equatorial-gauche and axial-anti, characterized by the equatorial or axial position of the isocyanato group as well as by the antiperiplanar or synclinal H–C–N=C torsional angle, were identified in the Raman and temperature-dependent IR vibrational spectra. The equatorial-anti conformer was found to be the most stable conformer. The enthalpy difference was determined to be 1.57(16) kJ mol-1. The rotational spectrum was recorded for the most stable conformer in a supersonic jet by an FTMW spectrometer in the frequency region between 11 and 21 GHz. The r0 structure was determined by fitting the MP2_full/6-311+G(d,p) structure to the ground-state rotational constants of one isotopic species. Zhou SX, Guirgis GA, Gause KK, Conrad AR, Tubergen MJ, Durig JR (2013) Microwave, Raman and infrared spectra, r0 structural parameters, conformational stability, and ab initio calculations of cyclobutyl isocyanate. Struct Chem 24(1):201-214

644

1,4-Pentadiene

7 Molecules with Five Carbon Atoms

539

CAS RN: 591-93-5 MGD RN: 183068 MW supported by QC calculations

C 5H 8 C2 (skew-skew) C1 (skew-syn) Cs (skew-skew‒)

skew-skew r0 [Å] a 1.334(2) b 1.508(2) b 1.090(2) b

skew-syn r0 [Å] a 1.334(2) b 1.508(2) b 1.090(2) b

skew-skew‒ r0 [Å] a 1.334(2) b 1.508(2) b 1.090(2) b

Bond angles C(1)=C(2)–C(3) C(2)–C(3)–C(4) C(2)=C(1)–H C(1)=C(2)–H C(2)–C(3)–H

θ0 [deg] a

θ0 [deg] a

θ0 [deg] a

Dihedral angles C(1)=C(2)−C(3)−C(4) C(2)−C(3)−C(4)=C(5)

τ0 [deg]

θ0 [deg]

θ0 [deg]

Bonds C(1)=C(2) C(2)–C(3) C–H

124.3 110.9 123.2(9) b 117.3(3) b 109.7(6) b

118.9 118.9

c

125.5 113.2 123.2(9) b 117.3(3) b 109.7(6) b

117.0 4.2

H2C

CH2

123.4 111.9 123.2(9) b 117.3(3) b 109.7(6) b skew-skew

123.3 -123.3

Reprinted with permission. Copyright 2013 American Chemical Society [a]. a

Parenthesized uncertainties in units of the last significant digit. Fixed at the value from the previous GED study [b]. c Assumed. b

skew-syn

skew-skew‒

The rotational spectra of 1,4-pentadiene were studied in a supersonic jet by Stark-modulation and FTMW spectroscopy in the MW and millimeter-wave region. Three conformers, skew-skew, skew-syn and skew-skew‒, all with the anticlinal C(1)‒C(2)‒C(3)‒C(4) chain and differing in the orientation of the C(2)‒C(3)‒C(4)‒C(5) chain (anticlinal, synperiplanar and anticlinal‒, respectively) were observed. The skew-syn conformer was found to be higher in energy than the skew-skew one by 172(66) cm‒1, whereas the skew-skew‒ conformer is higher in energy than the skew-syn one by 44(26) cm‒1. a. Hirota E, Watanabe R, Kawashima Y, Shigemune T, Matsumoto J, Murakami K, Mizoguchi A, Kanamori H, Nakajima M, Endo Y, Sumiyoshi Y (2013) Microwave studies on 1,4-pentadiene: CH2=CH-CH2-CH=CH2; transformations among the three rotational isomers. J Phys Chem A 117(39):9753-9760 b. McClelland, BW, Hedberg, K (1987) Structure and conformations of 1,4-pentadiene in the gas phase: An electron-diffraction investigation. J Amer Chem Soc 109:7304-7309

645 CAS RN: 157-40-4 MGD RN: 382254 GED combined with high-resolution IR

Spiropentane C 5H 8 D2d

540

7 Molecules with Five Carbon Atoms

and augmented by DFT computations Bonds C–H C(1)–C(3) C(1)–C(2)

r 0α [Å] a 1.105(2) 1.482(1) 1.557(3)

Angles H–C–H C(3)–C(1)–H C(2)–C(1)–H C(2)–C(3)–C(1)

θ 0α [deg] a

rg [Å] a 1.122(2) 1.485(1) 1.560(3)

113.7(19) 118.7(4) b 118.3(12) b 63.4(1) b 150.2(16)

βc

Reprinted with permission. Copyright 2017 American Chemical Society [a].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Dependent parameter. c Angle between the H–C–H bisector and the C(1)–C(2) bond. b

The GED experiment was carried out at Tnozzle = 298 K. Vibrational corrections to experimental internuclear distances, ∆r 0α = ra − r 0α , were calculated using quadratic force constants from B3LYP/cc-pVTZ computations as well as a Morse anharmonicity constant (assumed to be 2.0 Å–1). Corrections to the experimental ground-state rotational constants B0, ∆Bz = Bz − B0, were calculated using harmonic force constants computed at the level of theory as indicated above. Experimental ground-state rotational constants were taken from Refs. [b,c]. a. Sandwisch JW, Erickson BA, Hedberg K, Nibler JW (2017) Combined electron-diffraction and spectroscopic determination of the structure of spiropentane, C5H8. J Phys Chem A 121 (26):4923-4929 b. Price JE, Coulterpark KA, Masiello T, Nibler JW, Weber A, Maki A, Blake TA (2011) High-resolution infrared spectra of spiropentane, C5H8 J Mol Spectrosc 269:129-136. c. Maki A, Price JE, Harzan J, Nibler JW, Weber A, Masiello T, Blake TA (2015) Analysis of several highresolution infrared bands of spiropentane, C5H8 J Mol Spectrosc 312:68-77.

646 CAS RN: 311-75-1 MGD RN: 504907 IR supported by DFT calculations

Distances C(1)–C(2) C(1)…C(3) C(1)–H C(2)–H

rz [Å] a 1.5629 1.8855 1.0953 1.0971

Bond angle H−C(2)−H

θz [deg] a 111.393

Copyright 2012 with permission from Elsevier.

Bicyclo[1.1.1]pentane C 5H 8 D3h

7 Molecules with Five Carbon Atoms a

541

Uncertainties were not given in the original paper.

The rotationally resolved mid-IR spectra of the title compound were recorded by an FTIR spectrometer. The fundamental bands ν13 and ν18 near 850 cm-1 and the fundamental bands ν11 and ν17 near 1250 cm-1 were investigated. The rz structure was determined for two isotopic species, d0 and d1 (deuterium replaces a hydrogen atom on the C3 axis). Perry A, Martin MA, Nibler JW, Maki A, Weber A, Blake TA (2012) Coriolis analysis of several highresolution infrared bands of bicyclo[111]pentane-d0 and -d1. J Mol Spectrosc 276:22-32

647 CAS RN: 1195955-14-6 MGD RN: 158489 MW supported by ab initio calculations

6-Oxabicyclo[3.1.0]hexane – argon (1/1) Cyclopentene oxide – argon (1/1) C5H8ArO Cs O

Distance Rcm b

Ar

r0 [Å] a 3.94

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Uncertainty was not given in the original paper. Distance between Ar and the center-of-mass of the cyclopentene oxide monomer. b

The rotational spectrum of the binary van der Waals complex of cyclopentene oxide with argon was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 26.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, three 13C and 18O). Minei AJ, van Wijngaarden J, Novick SE, Pringle WC (2010) Determination of the structure of cyclopentene oxide and the argon-cyclopentene oxide van der Waals complex. J Phys Chem A 114(3):1427-1431

648 CAS RN: 1964-86-9 MGD RN: 534125 MW augmented by DFT calculations

Pyridine – ammonia (1/1) C5H8N2 Cs N H

H

Distances N(6)…H(3) N(7)…H(1)

r0 [Å] 2.326 b 2.710 b

Angles N(7)…N(6)−C(5) N(7)−H(3)…N(6)

θ0 [deg] a 157.5(1) 150.5 b

N

H

542

7 Molecules with Five Carbon Atoms

119.9 b

C(1)−H(1)…N(7)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter

The rotational spectrum of the title complex was recorded by a pulsed-jet FTMW spectrometer in the frequency range between 6.5 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of the main isotopic species; the remaining structural parameters were assumed at the vibrationally averaged B2PLYP-D3/m-aug-cc-pVTZdH values. The PES computations predicted the formation of the σ-type complex, whose existence was confirmed experimentally. Spada L, Tasinato N, Vazart F, Barone V, Caminati W, Puzzarini C. (2017) Noncovalent interactions and internal dynamics in pyridine-ammonia: A combined quantum-chemical and microwave spectroscopy study. Chem Eur J 23(20):4876-4883

649 CAS RN: 28171-19-9 MGD RN: 208750 MW

5-Methyl-2,4(1H,3H)-pyrimidinedione – water (1/1) Thymine – water (1/1) C5H8N2O3 O Cs

Distance H(2)…O(1)

r0 [Å] 1.97(8)

Angle O(2)…H(1)−N

θ0 [deg] a

CH3

HN

a

O

O H

H

N H

144(3)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of the binary complex of thymine with water was investigated by laser-ablation molecular-beam FTMW spectroscopy in the frequency region between 6.5 and 18 GHz. The main isotopic species and one isotopically enriched species with 18O in the water subunit were investigated. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 18O) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. López JC, Alonso JL, Peña I, Vaquero V (2010) Hydrogen bonding and structure of uracil-water and thyminewater complexes. Phys Chem Chem Phys 12(42):14128-14134

7 Molecules with Five Carbon Atoms

650 CAS RN: 123-54-6 MGD RN: 518531 GED combined with MS and augmented by QC computations

Bonds C(3)–C(2) C(2)–C(1) C=O C(1)–H(1) C(1)–H(2) C(1)–H(3) C(3)–H

rh1 [Å] a,b 1.540(4) 1 1.514(4) 1 1.204(4) 1.093(4) 2 1.097(4) 2 1.099(4) 2 1.095(4) 2

Bond angles C(2)–C(3)–C(4) C(3)–C(2)=O(1) C(3)–C(2)–C(1) C(4)–C(3)–H C(2)–C(3)–H H(1)–C(1)–C(2) H(2)–C(1)–C(2) H(2)–C(1)–H(3)

θh1 [deg] c

Dihedral angles O=C(2)–C(3)–C(4) H(1)–C(1)–C(2)–C(3)

τh1 [deg] c

ϕe

543

2,4-Pentanedione Acetylacetone C 5H 8O 2 C2

108.3(15) 123.9(20) 115.3(17) 108.0 d 110.8 d 110.3 d 110.1 d 106.8 d

87.0(82) 171.3 d 178.4 d

Reprinted with permission. Copyright 2014 American Chemical Society [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Structural parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/aug-cc-pVTZ computation. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Assumed at the value from computation at the level of theory indicated above. e Angle between the O(1)=C(2) bond and the C(1)C(2)C(3) plane. Molecular structures of acetylacetone tautomers from Refs. [b-e] were reinvestigated. Two GED experiments were carried out at two different nozzle temperatures, 300(5) and 671(7) K. At the higher temperature, acetylacetone was found to exist as a mixture of enol and diketo tautomers in amounts of 64(5)% and 36(5)%, respectively, corresponding to a free energy difference of 0.77(21) kcal mol-1. At the lower temperature, the diketo tautomer was not found. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/aug-cc-pVTZ computation. a. Belova NV, Oberhammer H, Trang NH, Girichev GV (2014) Tautomeric properties and gas-phase structure of acetylacetone. J Org Chem 79 (12):5412-5419 b. Lowrey AH, George C, D’Antonio P, Karle J (1971) Structure of acetylacetone by electron diffraction. J. Am Chem Soc 93:6399-6403 c. Andreassen AL, Bauer SH (1972) The structures of acetylacetone, trifluoroacetylacetone and trifluoroacetone. J Mol Struct 12:381-403.

544

7 Molecules with Five Carbon Atoms

d. Iijima K, Ohnogi A, Shibata S (1987) The molecular structure of acetylacetone as studied by gas-phase electron diffraction. J Mol Struct 156:111-118 e. Srinivasan R, Feenstra JS, Park ST, Xu S, Zewail AH (2004) Direct determination of hydrogen-bonded structures in resonant and tautomeric reactions using ultrafast electron diffraction. J Am Chem Soc 126:22662267.

651 CAS RN: 26567-75-9 MGD RN: 369569 GED combined with MS and augmented by QC computations

Bonds C(3)=C(4) C(2)–C(3) C(4)–C(5) C(2)–C(1) C(4)–O(1) C(2)=O(2) C(5)–H′ C(5)–H C(1)–H′ C(1)–H C(3)–H O(1)–H Bond angles C(4)=C(3)–C(2) C(3)=C(4)–O(1) C(3)–C(2)=O(2) C(3)=C(4)–C(5) C(3)–C(2)–C(1) C(2)–C(3)–H C(4)=C(3)–H H′–C(5)–C(4) H–C(5)–C(4) H′–C(1)–C(2) H–C(1)–C(2) H–C(5)–H H–C(1)–H H–O(1)–C(4) Dihedral angles O(1)–C(4)=C(3)–C(2) H′–C(1)–C(2)=O(2) H′–C(5)–C(4)=C(3)

ϕe

rh1 [Å] a,b T = 300 K T= 671 K 1.368(3) 1 1.370(3) 6 1 1.441(3) 1.443(3) 6 1 1.492(3) 1.494(3) 6 1 1.509(3) 1.511(3) 6 2 1.326(3) 1.318(4) 7 1.248(3) 2 1.240(4) 7 3 1.088(3) 1.094(4) 8 3 1.093(3) 1.099(4) 8 3 1.087(3) 1.094(4) 8 3 1.093(3) 1.099(4) 8 3 1.080(3) 1.086(4) 8 3 1.007(3) 1.013(4) 8

θh1 [deg] b,c

T = 300 K 121.1(8) 121.3(12) 121.0(20) 123.5(10) 119.4(10) 119.5(21) 119.5(21) 111.6(13) 4 109.8(13) 4 108.6(15) 5 109.0(15) 5 107.0(22) 111.2(20) 105.9 d

T= 671 K 120.0(10) 120.4(13) 120.3(15) 123.6(12) 118.0(20) 120.0(22) 120.0(22) 111.6(15) 9 109.7(15) 9 109.9(15) 10 110.3(15) 10 107.1(23) 107.7(21) 105.9 d

θh1 [deg]

T = 300 K 0.0 d 0.0 d 0.0 d 180.0 d

T= 671 K 0.0 d 0.0 d 0.0 d 180.0 d

Reprinted with permission. Copyright 2010 American Chemical Society [a].

(3Z)-4-Hydroxy-3-penten-2-one Acetylacetone, enol form C 5H 8O 2 Cs

7 Molecules with Five Carbon Atoms

545

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Structural parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/aug-cc-pVTZ computations. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Adopted from computation at the level of theory as indicated above. e Angle between the O(1)–C(4) bond and the C(5)C(4)C(3) plane. Molecular structures of acetylacetone tautomers from Refs. [b-e] were reinvestigated. Two GED experiments were carried out at two different temperatures, Tnozzle of 300(5) and 671(7) K. Only enol tautomer of acetylacetone (100(3)%) was found to be present at the lower temperature. At the higher temperature, acetylacetone was found to exist as a mixture of enol and diketo tautomers in amounts of 64(5)% and 36(5)%, respectively, corresponding to a free energy difference of 0.77(21) kcal mol-1. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force field from B3LYP/aug-cc-pVTZ computation. a. Belova NV, Oberhammer H, Trang NH, Girichev GV (2014) Tautomeric properties and gas-phase structure of acetylacetone. J Org Chem 79 (12):5412-5419 b. Lowrey AH, George C, D’Antonio P, Karle J (1971) Structure of acetylacetone by electron diffraction. J. Am Chem Soc 93:6399-6403 c. Andreassen AL, Bauer SH (1972) The structures of acetylacetone, trifluoroacetylacetone and trifluoroacetone. J Mol Struct 12:381-403. d. Iijima K, Ohnogi A, Shibata S (1987) The molecular structure of acetylacetone as studied by gas-phase electron diffraction. J Mol Struct 156:111-118 e. Srinivasan R, Feenstra JS, Park ST, Xu S, Zewail AH (2004) Direct determination of hydrogen-bonded structures in resonant and tautomeric reactions using ultrafast electron diffraction. J Am Chem Soc 126:22662267.

652 CAS RN: MGD RN: 533571 MW augmented by DFT calculations

Cyclobutanone – formic acid (1/1) C 5H 8O 3 C1 O O a

Distances O(6)…O(2) H(4)…O(6) H(5)…O(3)

r0 [Å] 2.7800 1.790 2.464

Angles O(6)…O(2)–C(1) O(6)…O(2)–C(1)=O(3)

τ0 [deg] a

H

OH

109 0.4

Reproduced with permission from the PCCP Owner Societies.

a

Uncertainties were not given in the original paper.

The rotational spectra of the binary complex of cyclobutanone with formic acid were recorded in a supersonic jet by Balle-Flygare type and chirped-pulse FTMW spectrometers in the frequency region between 2 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main and two D); the remaining structural parameters were constrained to their B3LYP-D3/6-311++G(d,p) values.

546

7 Molecules with Five Carbon Atoms

Evangelisti L, Spada L, Li W, Blanco S, López JC, Lesarri A, Grabow JU, Caminati W (2017) A butterfly motion of formic acid and cyclobutanone in the 1:1 hydrogen bonded molecular cluster. Phys Chem Chem Phys 19(1):204-209

653 CAS RN: MGD RN: 461417 MW supported by QC calculations

Cyclopropanecarboxylic acid – formic acid (1/1) C 5H 8O 4 Cs

O

O OH

Distances H(2)…O(4) O(1)…H(3) Rcm b

r0 [Å] a 1.36 2.25 4.11

H

OH

Reproduced with permission of AIP Publishing.

a b

Uncertainties were not given in the original paper. Distance between the centers of mass in both monomer subunits.

The rotational spectra of the binary complex of cyclopropanecarboxylic acid with formic acid were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 11 GHz. The partial r0 structure was determined from the ground-state rotational constants of six isotopic species (main, four 13C and D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Pejlovas AM, Lin W, Kukolich SG (2015) Microwave spectra and structure of the cyclopropanecarboxylic acidformic acid dimer. J Chem Phys 143(12):124311/1-124311/6 [http://dx.doi.org/10.1063/1.4931923]

654 CAS RN: 1481-36-3 MGD RN: 212960 MW augmented by ab initio calculations

Fluorocyclopentane Cyclopentyl fluoride C5H9F C1 F

Bonds C(1)–C(2) C(1)–C(3) C(2)–C(4) C(3)–C(5) C(4)–C(5) C(1)–F(6) C(1)–H(1) C(2)–H(2) C(3)–H(3) C(2)–H(4) C(3)–H(5) C(5)–H(6) C(4)–H(7) C(5)–H(8) C(4)–H(9)

a

r0 [Å] 1.531(3) 1.519(3) 1.553(3) 1.533(3) 1.540(3) 1.411(3) 1.092(2) 1.092(2) 1.097(2) 1.094(2) 1.092(2) 1.094(2) 1.095(2) 1.093(2) 1.092(2)

7 Molecules with Five Carbon Atoms

Bond angles C(3)–C(1)–C(2) C(1)–C(2)–C(4) C(1)–C(3)–C(5) C(2)–C(4)–C(5) C(3)–C(5)–C(4) F(6)–C(1)–H(1) H(2)–C(2)–H(4) H(3)–C(3)–H(5) H(6)–C(5)–H(8) H(7)–C(4)–H(9) F(6)–C(1)–C(2) H(1)–C(1)–C(3) F(6)–C(1)–C(3) H(1)–C(1)–C(2) H(2)–C(2)–C(1) H(3)–C(3)–C(1) H(4)–C(2)–C(1) H(5)–C(3)–C(1) H(2)–C(2)–C(4) H(3)–C(3)–C(5) H(4)–C(2)–C(4) H(5)–C(3)–C(5) H(6)–C(5)–C(4) H(7)–C(4)–C(5) H(8)–C(5)–C(4) H(9)–C(4)–C(5) H(6)–C(5)–C(3) H(7)–C(4)–C(2) H(8)–C(5)–C(3) H(9)–C(4)–C(2) Dihedral angles C(1)–C(2)–C(4)–C(5) C(2)–C(4)–C(5)–C(3)

547

θ0 [deg] a 105.5(5) 106.2(5) 102.9(5) 105.3(5) 104.6(5) 106.2(5) 107.6(5) 108.7(5) 108.1(5) 107.4(5) 108.9(5) 114.6(5) 107.6(5) 113.8(5) 109.0(5) 108.7(5) 110.0(5) 111.8(5) 112.7(5) 110.0(5) 111.3(5) 114.5(5) 109.6(5) 109.6(5) 111.8(5) 112.3(5) 109.2(5) 109.9(5) 113.3(5) 112.3(5)

τ0 [deg] a -2.6(3) 25.3(3)

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Parenthesized estimated uncertainties in units of the last significant digit.

Only one stable conformer, twisted (with C1 point-group symmetry), was predicted by ab initio calculations. The r0 structure of this conformer was determined by fitting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants. Durig JR, El Defrawy AM, Ganguly A, Gounev TK, Guirgis GA (2009) Conformational stability, r0 structural parameters, ab initio calculations, and vibrational assignment for fluorocyclopentane. J Phys Chem A 113(35):9675-9683

655 CAS RN: 400-53-3 MGD RN: 373165 GED augmented by QC computations

2,2,2-Trifluoroacetic acid trimethylsilyl ester Trimethylsilyl trifluoroacetate C5H9F3O2Si Cs

548

7 Molecules with Five Carbon Atoms

Bonds C(2)–F(2) C(2)–F(1) C(2)–C(1) C(1)=O(3) C(1)–O(4) O(4)–Si Si–C(6) Si–C(7)

rh1 [Å] a 1.317(6) 1.339(4) 1.556(3) 1.195(3) 1.307(5) 1.719(3) 1.857(2) 1.859(4)

Bond angles F–C(2)–C(1) C(2)–C(1)=O(3) C(2)–C(1)–O(4) C(1)–O(4)–Si O(4)–Si–C(7) O(4)–Si–C(6)

θh1 [deg] a

O

CH3

F

Si O

F

CH3 CH3

F

110.8(2) b 122.2(6) 108.4(5) 124.0(5) 102.4(5) 108.1(3)

Copyright 2010 with permission from Elsevier. a b

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value.

The GED experiment was carried out at Tnozzle ≈ 293 K. The title compound was found to exist as a single conformer with Cs overall symmetry (τ(C–C–O–Si) =180°). Staggered conformation was assumed for each of the methyl groups as well as for the trifluoromethyl group and the tert-butyl unit. Besides the main conformer with the antiperiplanar C–C–O–Si torsional angle, a gauche conformer with the synclinal C–C–O–Si dihedral angle ( ≈ 40°) was predicted by the MP2 and B3LYP methods in conjunction with 6-311++G(d,p) basis set. However, the energy difference between these two conformers was estimated to be very high (approximately 25 kJ mol−1 (MP2)). Therefore, the second conformer could not be detected in the GED experiment. The barrier to internal rotation of the Si(CH3)3 group about the Si–O bond was predicted to be 11 kJ mol−1. Vibrational corrections to experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/6-311++G(d,p) computation. Defonsi Lestard ME, Tuttolomondo ME, Varetti EL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2010) Gas-phase structure, rotational barrier and vibrational properties of trimethysilyl trifluoroacetate CF3C(O)OSi(CH3)3: An experimental and computational study. J Mol Struct 978 (1-3):114-123

656 CAS RN: 675-20-7 MGD RN: 144750 MW supported by ab initio calculations

Bonds N(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–N(1)

2-Piperidinone δ-Valerolactam C5H9NO C1 O

rs [Å] a 1.294 1.597 1.517 1.565 1.484 1.454

NH

7 Molecules with Five Carbon Atoms

Bond angles N(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(6)–N(1)–C(2)

549

θs [deg] a 116.4 113.2 109.2 109.3 128.7

Copyright 2012 with permission from Elsevier. a

Uncertainties were not given in the original paper.

The rotational spectrum of δ-valerolactam was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 18 GHz. The Kraitchman coordinates for the ring skeleton atoms were determined from the ground-state rotational constants of seven isotopic species (main, five 13C and 15N). From these coordinates, the partial rs structure is derived in this book. Bird RG, Vaquero-Vara V, Zaleski DP, Pate BH, Pratt DW (2012) Chirped-pulsed FTMW spectra of valeric acid, 5-aminovaleric acid, and δ-valerolactam: A study of amino acid mimics in the gas phase. J Mol Spectrosc 280:42-46

657 CAS RN: 609-36-9 MGD RN: 148042 MW augmented by ab initio calculations

Proline 2-Pyrrolidinylcarboxylic acid C5H9NO2 C1 O

Bonds N(1)–H N(1)–C(2) C(2)–C(6) C(6)–O(8) O(8)–H(1) C(6)=O(7) C(2)–H C(2)–C(3) C(3)–H(2) C(3)–H(3) C(3)–C(4) C(4)–H(4) C(4)–H(5) C(4)–C(5) C(5)–H(6) C(5)–H(7)

r see [Å] a 1.0078(11) 1.4785(18) 1.5321(18) 1.3343(19) 0.9861(23) 1.2027(18) 1.0891(23) 1.5307(18) 1.0903(23) 1.0865(23) 1.5262(17) 1.0872(23) 1.0909(23) 1.5215(15) 1.0931(23) 1.0880(23)

Bond angles C(2)–N(1)–H N(1)–C(2)–C(6) C(2)–C(6)–O(8) C(6)–O(8)–H(1) C(2)–C(6)=O(7) N(1)–C(2)–H N(1)–C(2)–C(3) C(2)–C(3)–H(2)

θ see [deg] a

111.84(19) 110.09(12) 114.17(21) 102.88(31) 122.41(21) 112.03(33) 105.79(13) 109.87(34)

N H

OH

550

C(2)–C(3)–H(3) C(2)–C(3)–C(4) C(3)–C(4)–H(4) C(3)–C(4)–H(5) C(3)–C(4)–C(5) C(4)–C(5)–H(6) C(4)–C(5)–H(7) Dihedral angles C(6)–C(2)–N(1)–H N(1)–C(2)–C(6)–O(8) C(2)–C(6)–O(8)–H(1) N(1)–C(2)–C(6)=O(7) H–N(1)–C(2)–H H–N(1)–C(2)–C(3) N(1)–C(2)–C(3)–H(2) N(1)–C(2)–C(3)–H(3) N(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–H(4) C(2)–C(3)–C(4)–H(5) C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–H(6) C(3)–C(4)–C(5)–H(7)

7 Molecules with Five Carbon Atoms

111.69(34) 102.304(80) 113.54(34) 110.17(34) 102.121(81) 109.92(34) 113.23(34) τ see [deg] a -119.13(18) 2.50(31) -0.41(56) -177.36(35) 0.01(56) 121.09(17) -90.76(56) 148.91(56) 26.47(18) -161.58(53) 77.19(53) -40.23(17) -79.57(55) 159.03(56)

Reprinted by permission of Taylor & Francis Ltd. Final version received 2 January 2017 [a]. a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see of the most stable conformer of the title molecule was determined from the previously published experimental ground-state rotational constants of nine isotopic species (parent, five 13C, 15N and two D) by taking into account rovibrational corrections calculated with the MP2/ccpVTZ harmonic and anharmonic (cubic) force fields. a.Vogt N, Demaison J, Krasnoshchekov SV, Stepanov NF, Rudolph HD (2017) Determination of accurate semiexperimental equilibrium structure of proline using efficient transformations of anharmonic force fields among the series of isotopologues. Mol Phys 115(8):942-951

GED supported by MW and augmented by QC computations

Bonds N(1)–C(2) N(1)–C(5) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(2)–C(6) C–O(8) C=O(7) C–H N–H O–H

ra [Å] a,b 1.486(8) 1 1.490(8) 1 1.546(8) 1 1.540(8) 1 1.536(8) 1 1.547(8) 1 1.342(7) 1.209(7) 1.089 c 1.008 0.980

C1 (IIa)

7 Molecules with Five Carbon Atoms

Bond angles C(3)–C(2)–N C(4)–C(3)–C(2) C(5)–C(4)–C(3) N–C(5)–C(4) C–N–C C(6)–C(2)–N O(7)=C–C O(7)=C–O(8)

θh1 [deg] a

Dihedral angles C(4)–C(3)–C(2)–N C(5)–C(4)–C(3)–C(2) N–C(5)–C(4)–C(3) C(2)–N–C(5)–C(4) C(3)–C(2)–N–C(5) C(6)–C(2)–N–C(5) O(7)=C(6)–C(2)–C(3)

τh1 [deg] a

551

105.7 100.9(3) 101.9 d 103.7 d 108.3 d 111.9 122.7 125.7(4)

27.2 -42.0 d 36.0 d -24.0 d 2.0 d 116.4(2) -60.0(2)

Reproduced with permission of SNCSC [b].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from DFT computation as indicated below. c Average value. d Dependent parameter. b

The QC computations (MP2/6-311++G** and M06-2X/aug-cc-pVTZ) predicted an existence of four conformers (all with the C1 point-group symmetry) differing in the conformations of the pyrrolidine ring as well as in the locations of the O–H bond with respect to the nitrogen atom. Two lowest-energy conformers, IIa and IIb, are stabilized by the O–H…N hydrogen bond. The GED experiments were carried out at Tnozzle = 443(2) K. The ratio of the conformers was determined to be Ia : Ib : IIa : IIb = 10 : 20(19) : 43(8) : 27(12) (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from DFT computation. Structural differences between the conformers were fixed at the computed values. Structural parameters are presented for the predominant conformer (IIa). b. Belyakov AV, Gureev MA, Garabadzhiu AV, Losev VA, Rykov AN (2015) Determination of the molecular structure of gaseous proline by electron diffraction, supported by microwave and quantum chemical data. Struct Chem 26 (5-6):1489-1500.

658 CAS RN: MGD RN: 156785 MW augmented by ab initio calculations

2,2-Dimethylpropanenitrile – sulfur trioxide (1/1) Pivalonitrile – sulfur trioxide (1/1) C5H9NO3S C3v H 3C

H3C

a

Distance N…S

r0 [Å] 2.394(19)

Angle N…S=O

θ0 [deg] 92.8 b

H 3C

O C

N

S O

O

552

7 Molecules with Five Carbon Atoms

Copyright 2010 with permission from Elsevier.

a b

Parenthesized uncertainty in units of the last significant digit. Fixed at the value from MP2/aug-cc-pVTZ calculations.

The rotational spectrum of the binary complex was recorded by a pulsed supersonic beam FTMW spectrometer in the spectral region at 3.5 GHz. The complex exhibits a free or nearly free internal rotation about its C3 axis. The partial r0 structure was obtained from the ground-state rotational constant of the main isotopic species assuming that the remaining structural parameters were not changed upon complexation. Sedo G, Leopold KR (2010) Microwave spectrum of (CH3)3CCN-SO3. J Mol Spectrosc 262(2):135-138

659 CAS RN: 51-45-6 MGD RN: 130641 GED combined with MW and augmented by QC computations

Histamine 4-(2-Aminoethyl)imidazole 1H-Imidazole-4-ethanamine C5H9N3 NH2 C1 N HN

3

1.328(2) 1.385(3) 1.371(3) 1.098(4) 1.380(3) 1.026(3) 1.391(3) 1.098(4) 1.508(3) 1.535(2) 1.115(4) 1.117(4) 1.467(2) 1.117(4) 1.118(4) 1.032(4) 1.034(4)

1.331(2) 1.385(3) 1.370(3) 1.097(4) 1.379(3) 1.026(3) 1.389(3) 1.098(4) 1.514(3) 1.534(2) 1.115(4) 1.118(4) 1.470(2) 1.116(4) 1.114(4) 1.038(4) 1.034(4)

1.327(2) 1.387(3) 1.373(3) 1.098(4) 1.381(3) 1.026(3) 1.392(3) 1.098(4) 1.503(3) 1.549(2) 1.116(4) 1.112(4) 1.462(2) 1.117(4) 1.115(4) 1.033(4) 1.037(4)

3

3

3

1.322(2)1 1.379(3) 2 1.359(3) 3 1.078(4) 4 1.369(3) 5 1.006(3) 6 1.382(3) 7 1.078(4) 8

1.323(2) 1 1.380(3) 2 1.360(3) 3 1.078(4) 4 1.369(3) 5 1.007(3) 6 1.382(3) 7 1.078(4) 8

A-a

N(1)=C(2) N(1)–C(5) C(2)–N(3) C(2)–H N(3)–C(4) N(3)–H C(4)=C(5) C(4)–H C(5)–C(6) C(6)–C(7) C(6)–H(1) C(6)–H(2) C(7)–N(8) C(7)–H(3) C(7)–H(4) N(8)–H(5) N(8)–H(6) Bonds N(1)=C(2) N(1)–C(5) C(2)–N(3) C(2)–H N(3)–C(4) N(3)–H C(4)=C(5) C(4)–H

A-a

G-Ib

G-Ib

3

rg [Å] a

3

G-Ic

re [Å] a,b G-Ic

1.322(2) 1 1.379(3) 2 1.360(3) 3 1.078(4) 4 1.369(3) 5 1.007(3) 6 1.383(3) 7 1.078(4) 8

3

G-Vb

3

G-Vc

1.329(2) 1.386(3) 1.370(3) 1.097(4) 1.380(3) 1.026(3) 1.391(3) 1.098(4) 1.511(3) 1.537(2) 1.115(4) 1.116(4) 1.464(2) 1.116(4) 1.121(4) 1.036(4) 1.035(4)

1.329(2) 1.387(3) 1.370(3) 1.098(4) 1.380(3) 1.026(3) 1.392(3) 1.098(4) 1.509(3) 1.547(2) 1.116(4) 1.116(4) 1.460(2) 1.116(4) 1.116(4) 1.036(4) 1.035(4)

3

3

G-Vb

1.323(2) 1 1.381(3) 2 1.358(3) 3 1.077(4) 4 1.368(3) 5 1.007(3) 6 1.383(3) 7 1.078(4) 8

G-Vc

1.324(2) 1 1.381(3) 2 1.358(3) 3 1.077(4) 4 1.368(3) 5 1.007(3) 6 1.383(3) 7 1.078(4) 8

7 Molecules with Five Carbon Atoms

1.497(3) 9 1.522(2) 10 1.093(4) 1.096(4) 1.456(2) 15 1.094(4) 1.097(4) 1.014(4) 1.015(4)

C(5)–C(6) C(6)–C(7) C(6)–H(1) C(6)–H(2) C(7)–N(8) C(7)–H(3) C(7)–H(4) N(8)–H(5) N(8)–H(6) Bond angles

Dihedral angles H–C(2)=N(1)–C(5) C(2)=N(1)–C(5)=C(4) C(2)=N(1)–C(5)–C(6) N(1)=C(2)–N(3)–C(4) N(1)=C(2)–N(3)–H N(1)–C(5)–C(6)–C(7) C(2)–N(3)–C(4)–H C(5)–C(6)–C(7)–N(8) C(6)–C(7)–N(8)–H(5) C(6)–C(7)–N(8)–H(6)

1.499(3) 9 1.523(2) 10 1.093(4) 11 1.093(4) 13 1.456(2) 15 1.098(4) 16 1.093(4) 18 1.017(4) 1.015(4)

1.497(3) 9 1.532(2) 10 1.095(4) 11 1.095(4) 13 1.451(2) 15 1.092(4) 16 1.094(4) 18 1.015(4) 1.016(4)

3

111.7(2) 20 126.0(2) 21 121.7(2) 22 107.4(2) 23 126.3(2) 24 122.3(2) 25 113.2(1) 26 110.4(2) 109.1(2) 109.1(2) 109.0(2) 109.9(2) 36 108.9(2) 108.4(2) 114.3(2) 110.0(2) 109.3(2) 108.1(2)

111.7(2) 20 126.0(2) 21 121.7(2) 22 107.4(2) 23 126.3(2) 24 122.5(2) 25 112.6(1) 26 109.5(2) 28 109.3(2) 30 109.0(2) 32 109.3(2) 34 109.6(2) 36 108.4(2) 38 109.3(2) 40 108.1(2) 42 108.8(2) 44 109.9(2) 45 113.8(2) 46

111.7(2) 20 126.0(2) 21 121.4(2) 22 107.3(2) 23 126.3(2) 24 122.3(2) 25 112.8(1) 26 109.4(2) 28 109.5(2) 30 109.6(2) 32 109.2(2) 34 115.5(2) 36 108.5(2) 38 109.3(2) 40 108.2(2) 42 109.9(2) 44 109.2(2) 45 108.0(2) 46

3

3

3

A-a 179.6(2) 48 0.1(2) 49 179.2(2) 50 -0.1(2) 51 179.5(2) 52 -68.0(2) 53 180.0(2) 54 178.8(2) 178.1(2) -65.6(2)

G-Ib

G-Ib 179.4(2) 48 0.4(2) 49 178.5(2) 50 -0.2(2) 51 179.4(2) 52 -67.8(2) 53 -179.8(2) 54 -62.9(2) 55 63.8(2) 180.0(2)

3

θe [deg] a,b

3

A-a

N(1)=C(2)–N(3) N(1)=C(2)–H N(1)–C(5)–C(6) C(2)–N(3)–C(4) C(2)–N(3)–H N(3)–C(4)–H C(5)–C(6)–C(7) C(5)–C(6)–H(1) C(5)–C(6)–H(2) C(7)–C(6)–H(1) C(7)–C(6)–H(2) C(6)–C(7)–N(8) C(6)–C(7)–H(3) C(6)–C(7)–H(4) N(8)–C(7)–H(4) C(7)–N(8)–H(5) C(7)–N(8)–H(6) H(3)–C(7)–N(8)

553

G-Ic

τe [deg] a,b

G-Ic 179.7(2) 48 0.4(2) 49 178.7(2) 50 -0.2(2) 51 179.5(2) 52 -65.1(2) 53 179.5(2) 54 -60.8(2) 55 -57.7(2) 58.7(2)

1.500(3) 9 1.524(2) 10 1.093(4) 12 1.094(4) 14 1.452(2) 15 1.094(4) 17 1.100(4) 19 1.017(4) 1.014(4)

3

1.499(3) 9 1.534(2) 10 1.094(4) 12 1.095(4) 14 1.450(2) 15 1.094(4) 17 1.094(4) 19 1.017(4) 1.015(4)

3

G-Vb

G-Vc

111.6(2) 20 126.0(2) 21 122.6(2) 22 107.4(2) 23 126.2(2) 24 122.3(2) 25 113.0(1) 27 108.4(2) 29 110.1(2) 31 109.6(2) 33 108.0(2) 35 109.6(2) 37 108.9(2) 39 108.3(2) 41 114.1(2) 43 108.9(2) 110.2(2) 108.2(2) 47

111.6(2) 20 126.0(2) 21 122.5(2) 22 107.5(2) 23 126.2(2) 24 122.3(2) 25 112.6(1) 27 108.7(2) 29 109.7(2) 31 109.4(2) 33 109.0(2) 35 115.3(2) 37 109.1(2) 39 108.5(2) 41 108.3(2) 43 108.6(2) 109.0(2) 108.2(2) 47

3

G-Vb 179.9(2) 48 -0.0(2) 49 179.7(2) 50 -0.3(2) 51 179.4(2) 52 -58.1(2) 53 -179.9(2) 54 73.9(2) 56 -55.2(2) -173.0(2)

Reproduced with permission from the PCCP Owner Societies [a].

3

A-a

3

G-Ib

3

G-Ic

3

G-Vc 179.8(2) 48 0.0(2) 49 178.5(2) 50 -0.3(2) 51 179.4(2) 52 -67.1(2) 53 179.8(2) 54 67.0(2) 56 -48.7(2) 65.8(2)

554

7 Molecules with Five Carbon Atoms

3

3

G-Vb

G-Vc

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed. Each refined parameter was constrained to the value from MP2/TZVP calculation.

b

Two tautomers of histamine, 1H-imidazole-4-ethanamine (denoted as N(3)H) and 1H-imidazole-5-ethanamine (denoted as N(1)H), were detected by GED method at Tnozzle of 390…395 K. Mechanism of tautomerization due to simultaneous intermolecular transfer of hydrogens in a histamine dimer was suggested to explain the distribution of tautomers in the experiments by different techniques. The GED model included five conformers of N(3)H tautomer (denoted as 3A-a, 3G-Ib, 3G-Ic, 3G-Vb and 3G-Vc) and one conformer of N(1)H tautomer (1GIVa), characterized by the antiperiplanar (A) or synclinal (G) conformation of the CCCN(8) moiety. The conformational distribution ratio could not be determined; therefore, it was assumed to be 29(3), 29(4), 19(10), 4(6), 9(8) and 10(1) % for 1G-IVa, 3G-Ib, 3G-Ic, 3G-Vb, 3G-Vc and 3A-a, respectively, according to results of the thermochemical analysis at the MP2/TZVP level. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, and rotational constants, ∆Be = Be − B0, were calculated from the MP2/SVP quadratic and cubic force constants by taking into account non-linear kinematic effects. Rotational constants were taken from Refs. [b,c]. a. Tikhonov DS, Rykov AN, Grikina OE, Khaikin LS (2016) Gas phase equilibrium structure of histamine. Phys Chem Chem Phys 18 (8):6092-6102 b. Vogelsanger B, Godfrey PD, Brown RD (1991) Rotational spectra of biomolecules: Histamine. J Am Chem Soc 113:7864-7869. c. Godfrey P, Brown RD (1998) Proportions of species observed in jet spectroscopy – vibrational energy effects: Histamine tautomers and conformers. J Am Chem Soc 120:10724-10732.

660 CAS RN: 51-45-6 MGD RN: 552014 GED supported by MW and augmented by QC computations

Bonds N(1)–C(2) N(1)–C(5) N(1)–H C(2)=N(3) C(2)–H N(3)–C(4) C(4)=C(5) C(4)–H C(5)–C(6) C(6)–C(7) C(6)–H(1) C(6)–H(2) C(7)–N(8)

re [Å] a,b 1.358(4) 1.375(3) 1.015(4) 1.318(3) 1.079(4) 1.372(3) 1.384(3) 1.080(4) 1.489(3) 1.525(3) 1.093(4) 1.098(4) 1.469(3)

Histamine 5-(2-Aminoethyl)imidazole 1H-Imidazole-5-ethanamine C5H9N3 C1 H N

rg [Å] a 1.370(4) 1.386(3) 1.034(4) 1.324(3) 1.099(4) 1.378(3) 1.392(3) 1.100(4) 1.498(3) 1.538(3) 1.114(4) 1.120(4) 1.480(3)

N

NH2

7 Molecules with Five Carbon Atoms

C(7)–H(3) C(7)–H(4) N(8)–H(5) N(8)–H(6)

1.096(4) 1.093(4) 1.016(4) 1.015(4)

Bond angles N(1)–C(2)=N(3) N(1)–C(2)–H C(5)–N(1)–H N(1)–C(5)–C(6) C(2)=N(3)–C(4) N(3)–C(4)–H C(5)–C(6)–C(7) C(5)–C(6)–H(1) C(5)–C(6)–H(2) C(7)–C(6)–H(1) C(7)–C(6)–H(2) C(6)–C(7)–N(8) C(6)–C(7)–H(3) C(6)–C(7)–H(4) N(8)–C(7)–H(4) C(7)–N(8)–H(5) C(7)–N(8)–H(6) N(8)–C(7)–H(3)

θe [deg] a,b

Dihedral angles H–C(2)–N(1)–C(5) C(2)–N(1)C(5)=C(4) C(2)–N(1)–C(5)–C(6) N(1)–C(2)=N(3)–C(4) C(4)=C(5)–N(1)–H N(1)–C(5)–C(6)–C(7) C(2)=N(3)–C(4)–H C(5)–C(6)–C(7)–N(8) C(6)–C(7)–N(8)–H(5) C(6)–C(7)–N(8)–H(6)

τe [deg] a,b

555

1.118(4) 1.114(4) 1.036(4) 1.034(4)

111.3(2) 122.6(2) 121.8(2) 122.5(2) 104.4(2) 121.5(2) 113.2(2) 108.3(2) 110.8(2) 109.5(2) 108.4(2) 110.0(2) 109.4(2) 109.2(2) 107.9(2) 109.3(2) 110.1(2) 112.8(2)

179.3(2) 0.5(2) 180.0(2) 0.5(2) 175.1(2) -44.3(2) -179.9(2) 67.3(2) 70.0(2) -173.5(2)

Reproduced with permission from the PCCP Owner Societies [a].

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed. Each refined parameter was constrained to the value from MP2/TZVP calculation.

b

Two tautomers of histamine, 1H-imidazole-4-ethanamine (denoted as N(3)H) and 1H-imidazole-5-ethanamine (denoted as N(1)H), were detected by GED method (Tnozzle = 390…395 K). Mechanism of tautomerization due to simultaneous intermolecular transfer of hydrogens in a histamine dimer was suggested to explain the distribution of tautomers in the experiments by different techniques. The GED model included one conformer of N(1)H tautomer (1G-IVa) and five conformers of N(3)H tautomer (denoted as 3A-a, 3G-Ib, 3G-Ic, 3G-Vb and 3GVc), characterized by the antiperiplanar (A) or synclinal (G) conformation of the CCCN(8) moiety. The conformational distribution ratio could not be determined and, therefore, it was assumed to be 29(3), 29(4), 19(10), 4(6), 9(8) and 10(1) % for 1G-IVa, 3G-Ib, 3G-Ic, 3G-Vb, 3G-Vc and 3A-a, respectively, according to results of the thermochemical analysis at the MP2/TZVP level. Total corrections to the experimental internuclear distances, ∆re = ra − re, and rotational constants, ∆Be = Be − B0, were calculated from the MP2/SVP quadratic and cubic force constants by taking into account non-linear kinematic effects. Rotational constants were taken from Refs. [b,c].

556

7 Molecules with Five Carbon Atoms

a. Tikhonov DS, Rykov AN, Grikina OE, Khaikin LS (2016) Gas phase equilibrium structure of histamine. Phys Chem Chem Phys 18 (8):6092-6102 b. Vogelsanger B, Godfrey PD, Brown RD (1991) Rotational spectra of biomolecules: Histamine. J Am Chem Soc 113:7864-7869. c. Godfrey P, Brown RD (1998) Proportions of species observed in jet spectroscopy – vibrational energy effects: Histamine tautomers and conformers. J Am Chem Soc 120:10724-10732.

661 CAS RN: 78129-68-7 MGD RN: 954389 GED augmented by ab initio computations

Bonds C≡P C–C C(2)–C(m) C(2)–C(1) C–H

rh1[Å] a 1.5500(11) 1.5255(7) b 1.5421(8) c,d 1.4759(17) c,d 1.090(2)

Bond angles C–C–C H–C–H C–C–H C–C–H(1ʹ) C–C–H(1ʹʹ)

θh1 [deg] a

2,2-Dimethylpropylidynephosphine tert-Butylphosphaacetylene C5H9P C3 H 3C

H 3C

CH3

C P

108.9(1) 108.5(5) e 110.9(2) b,e 110.2(3) d,f 111.3(2) d,f

Reproduced with permission from The Royal Society of Chemistry [a].

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Average value. c Difference between the C(2)–C(1) and C(2)–C(m) bond lengths was constrained to the value from MP2/6311+G* calculation. d Dependent parameter. e Constrained to the value from calculation as indicated above. f Difference between the C–C–H(1ʹ) and C–C–H(1ʹʹ) bond angles was constrained at the value from calculation as indicated above. b

Molecular structure from Ref. [b] was reinvestigated. The GED experiment was carried out at room temperature. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from MP2/6-311+G* computation. a. Wann DA, Masters SL, Robertson HE, Green M, Kilby RJ, Russell CA, Jones C, Rankin DWH (2011) Multiple bonding versus cage formation in organophosphorus compounds: The gas-phase structures of tricycloP3(CBut)2Cl and P≡C–But determined by electron diffraction and computational methods. Dalton Trans 40 (20):5611-5616 b. Oberhammer H, Becker G, G. Gresser G (1981) Molecular structures of phosphorus compounds. Part IX. Gasphase structure of 2,2-dimethylpropylidynephosphitne. J Mol Struct 75:283-289.

7 Molecules with Five Carbon Atoms

557

662 CAS RN: 358-03-1 MGD RN: 216215 MW supported by ab initio calculations

3,3-Difluoropentane C5H10F2 C2 (gauche-gauche) C1 (anti-gauche) F

H 3C

anti-gauche r0 [Å] a 1.5267(53) 1.5165(25) 1.5151(21) 1.5300(62)

rs [Å] a 1.539(21) 1.503(52) 1.554(14) 1.532(44)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5)

θ0 [deg] a

θs [deg] a

θ0 [deg] a

θs [deg] a

Dihedral angles C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5)

τ0 [deg] a

τs [deg] a

τ0 [deg] a

τs [deg] a

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5)

113.17(31) 117.03(25) 113.96(34)

177.68(17) 60.77(56)

111.1(36) 114.4(38) 112.7(32)

176.7(10) 64.9(30)

gauche-gauche r0 [Å] a 1.5202(60) 1.5141(33)

114.20(21) 117.40(42)

57.9(3)

F CH3

rs [Å] a 1.515(10) 1.506(10)

114.4(10) 118.5(10)

57.2(10)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

gauche-gauche

anti-gauche

The rotational spectra of the main and all singly substituted 13C isotopic species (in natural abundance) were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers. Three conformers, gauche-gauche, anti-anti and anti-gauche, characterized by the antiperiplanar and/or synclinal C–C–C–C dihedral angles were observed. The partial r0 and rs structures were determined from the ground-state rotational constants of six and four isotopic species for the anti-gauche and gauche-gauche conformers, respectively. According to prediction of MP2/6-311++G(2d,2p) calculations, the anti-gauche conformer is higher in energy than the most stable gauche-gauche conformer by 100 cm-1, whereas the anti-anti conformer is only by 18 cm-1 lower in energy than the gauche-gauche one. Obenchain DA, Elliott AA, Steber AL, Peebles RA, Peebles SA, Wurrey CJ, Guirgis GA (2010) Rotational spectrum of three conformers of 3,3-difluoropentane: Construction of a 480 MHz bandwidth chirped-pulse Fourier-transform microwave spectrometer. J Mol Spectrosc 261(1):35-40

663

2-(Dimethylamino)-2-methoxyacetonitrile

558

7 Molecules with Five Carbon Atoms

CAS RN: 4637-22-3 MGD RN: 305851 GED augmented by DFT computations

Bonds C(2)–N(1) C(3)–C(2) C(3)≡N(4) O(5)–C(2) C(6)–O(5) C(7)–N(1) C(8)–N(1) C–H Bond angles C(3)–C(2)–N(1) N(4)≡C(3)–C(2) O(5)–C(2)–N(1) C(6)–O(5)–C(2) C(7)–N(1)–C(2) C(8)–N(1)–C(2) H–C–(N,O) Dihedral angles N(4)≡C(3)–C(2)–N(1) O(5)–C(2)–N(1)–C(3) C(6)–O(5)–C(2)–C(3) C(7)–N(1)–C(2)–C(3)

ϕ1 e ϕ2 f

C5H10N2O C1 (gauche-anti) C1 (anti-gauche)

rh1 [Å] a,b gauche-anti anti-gauche 1.426(8) 1.448(8) 1.528(23) 1.531(23) 1.149(12) 1.149(12) 1.423(12) 1.401(12) 1.417(12) 1.422(12) 1.461(8) 1.463(8) 1.464(8) 1.459(8) 1.111(13) c 1.111(13) c

θh1 [deg] a,b

gauche-anti 106.5(57) 165.4(101) 113.1(32) 104.8(28) 112.8(66) 119.3(30) 104.5(28) c

anti-gauche 109.1(57) 162.5(101) 113.6(32) 103.6(28) 113.6(66) 117.5(30) 104.2(28) c

gauche-anti

τe [deg]

gauche-anti 179.3 d -123.0 d 67.9 d -165.8 d -61.9 d -168.6 d

anti-gauche 36.3 d -120.7 d 164.9 d 56.0 d 163.3 d -70.5 d

Reproduced with permission of SNCSC.

anti-gauche Parenthesized uncertainties in units of the last significant digit are 3σ values. b Differences between similar parameters in each conformer and between parameters of the conformers were assumed at the values from B3LYP/cc-pVTZ computations. c Average value. d Taken from computation at the level of theory as indicated above. e Angle of rotation about the N(1)–C(2) bond, C(8)–N(1)–C(2)–O(5). f Angle of rotation about the C(2)–O(5) bond, C(6)–O(5)–C(2)–N(1). a

The GED experiment was carried out at Tnozzle = 333 K. The best fit to the experimental intensities was obtained for the mixture of the gauche-anti (65%) and antigauche (35%) conformers characterized by the synclinal or antiperiplanar C(8)–N(1)–C(2)–O(5) and C(6)– O(5)–C(2)–N(1) dihedral angles. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from QC computations. Al'tova EP, Kostyanovskii RG, Shishkov IF (2014) Molecular structure of (cyanomethoxy)(dimethylamino)methane as studied by gas-phase electron diffraction and quantum-chemical calculations. Russ J Phys Chem A / Zh Fiz Khim 88 / 88 (4 / 4):667-670 / 653-656

7 Molecules with Five Carbon Atoms

559

664

Tetrahydro-2-methylfuran

CAS RN: 96-47-9

MGD RN: 470555 MW supported by QC calculations

C5H10O

C1

a

Bonds O(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) O(1)–C(5) C(2)–C(6)

rs [Å] 1.404(21) 1.536(21) 1.5132(86) 1.5304(23) 1.498(12) 1.5139(41)

Bond angles O(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–O(1) C(5)–O(1)–C(2) O(1)–C(2)–C(6) C(3)–C(2)–C(6)

θs [deg] a

Dihedral angles C(5)–C(4)–C(3)–C(2) C(4)–C(3)–C(2)–C(6) C(4)–C(3)–C(2)–O(1) C(3)–C(4)–C(5)–O(1) C(4)–C(5)–O(1)–C(2) C(5)–O(1)–C(2)–C(3) C(5)–O(1)–C(2)–C(6) C(5)–O(1)–C(3)–C(2) C(4)–C(3)–O(1)–C(2)

τs [deg] a

O

CH3

105.54(89) 102.34(94) 104.07(20) 107.01(23) 102.49(68) 105.8(30) 117.4(32)

-18.26(13) 157.13(18) 39.483(67) -6.48(21) 31.081(70) -43.334(58) -168.49(31) 135.715(48) -139.950(54)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 2 and 26.5 GHz. The MP2/6-311++G(d,p) calculations predicted existence of two conformers with an envelope configuration of the ring differing in the position of the methyl group. The conformer with the axial methyl group was predicted to be higher in energy than that with the equatorial one by 4.59 kJ mol-1 (CCSD(T)/6-311++G(d,p)). Only equatorial conformer was assigned in the spectrum. The rs structure of the heavy-atom skeleton was determined from the ground-state rotational constants of seven isotopic species (main, five 13C and 18O). Van V, Stahl W, Nguyen HVL (2016) The heavy atom microwave structure of 2-methyltetrahydrofuran. J Mol Struct 1123:24-29

560

7 Molecules with Five Carbon Atoms

665 CAS RN: 1120-98-5 MGD RN: 210259 MW augmented by DFT calculations

5-Methyl-1,3-dioxane C5H10O2 Cs

Distances C(2)–O(3) O(3)–C(4) C(4)–C(5) C(5)–C(7) O(1)..O(3) C(4)..C(6) C(2)..C(5)

r0 [Å]a 1.404(3) 1.425(6) 1.525(5) 1.530(4) 2.338(2) 2.470(2) 2.791(2)

rs [Å]a 1.399(4) 1.405(7) 1.530(5) 1.526(5) 2.336(2) 2.465(2) 2.786(2)

Bond angles O(1)–C(2)–O(3) C(2)–O(3)–C(4) O(3)–C(4)–C(5) C(4)–C(5)–C(6)

θ0 [deg]a

θs [deg]a

Dihedral angles

τ0 [deg]a

τs [deg]a

b

α βc γd

CH3

O

112.7(3) 110.8(5) 110.9(5) 108.1(4)

55.2(12) 47.7(12) 128.2(11)

O

113.2(4) 110.9(6) 111.5(5) 107.4(4)

54.6(13) 46.9(13) 129.5(12)

Reproduced with permission of SNCSC

a

Parenthesized uncertainties in units of the last significant digit. Angle between the O(1)–C(2)–O(3) and O(1)–C(6)–C(4)–O(3) planes. c Angle between the C(4)–C(5)–C(6) and O(1)–C(6)–C(4)–O(3) planes. d Angle between the C(5)–C(7) bond and the C(4)–C(5)–C(6) plane. b

The rotational spectrum of the title compound was recorded in the frequency range between 18 and 42 GHz. Only the chair conformer with the methyl group in the equatorial position was observed. The r0 and rs structures of the heavy-atom skeleton were determined from the ground-state rotational constants of six isotopic species (main, 18O and four 13C); the remaining structural parameters were fixed to the B3PW91/aug-cc-pVDZ values. Mamleev AK, Gunderova LN, Galeev RV, Shapkin AA, Faizullin MG, Nikitina AP, Shornikov DV (2010) Structure and spectra of 1,3-dioxanes. Microwave spectrum, structural parameters, and ab initio calculations of 5-methyl-1,3-dioxane. Zh Strukt Khim 51(2):253-258; J Struct Chem (Engl Transl) 51(2):238-243

666 CAS RN: 22900-10-3 MGD RN: 394148 MW augmented by ab initio calculations

2-Deoxy-ß-D-erythro-pentopyranose 2-Deoxy-ß-D-ribopyranose 2-Deoxy-D-ribose C5H10O4 C1 HO

O

Bonds C(1)–C(2)

r0 [Å] a 1.5220(32)

rs [Å] a 1.596(20)

r see [Å] a 1.5182(14)

HO

OH

7 Molecules with Five Carbon Atoms

561

C(2)–C(3) C(3)–C(4) C(4)–C(5) C(1)–O(6) C(1)–O(1) C(3)–O(3) C(4)–O(4) C(1)–H(1) C(2)–H(2) C(2)–H(2ꞌ) C(3)–H(3) C(4)–H(4) C(5)–H(5ꞌ) C(5)–H(5) O(1)–H(1ꞌ) O(3)–H(3ꞌ) O(4)–H(4ꞌ) C(5)–O(6)

1.5299(32) 1.5286(31) 1.5147(36) 1.4187(33) 1.4111(34) 1.4180(35) 1.4313(35) 1.0906(15) 1.0907(15) 1.0879(15) 1.0898(15) 1.0898(15) 1.0873(15) 1.0910(15) 0.9604(15) 0.9633(15) 0.9624(15) 1.4473(51) b

1.477(17) 1.5205(49) 1.5109(65)

1.4347(78) b

1.5258(14) 1.5226(14) 1.5133(16) 1.4183(14) 1.4072(15) 1.4145(15) 1.4262(15) 1.09050(70) 1.09060(70) 1.08789(70) 1.08969(70) 1.08970(70) 1.08719(70) 1.09090(70) 0.96041(70) 0.96330(70) 0.96239(70) 1.4186(22) b

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) O(6)–C(1)–C(2) O(6)–C(1)–O(1) C(2)–C(3)–O(3) C(3)–C(4)–O(4) O(6)–C(1)–H(1) C(1)–C(2)–H(2) C(1)–C(2)–H(2ꞌ) C(2)–C(3)–H(3) C(3)–C(4)–H(4) C(4)–C(5)–H(5ꞌ) C(4)–C(5)–H(5) C(1)–O(1)–H(1) C(3)–O(3)–H(3ꞌ) C(4)–O(4)–H(4ꞌ) C(4)–C(5)–O(6) C(5)–O(6)–C(1) O(1)–C(1)–C(2) O(3)–C(3)–C(4)

θ0 [deg] a

θs [deg] a

θ see [deg] a

Dihedral angles C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(5)–O(6)–C(1)–C(2) O(6)–C(1)–C(2)–C(3) C(1)–C(2)–C(3)–O(3) C(2)–C(3)–C(4)–O(4) C(5)–O(6)–C(1)–H(1) O(6)–C(1)–C(2)–H(2ꞌ) O(6)–C(1)–C(2)–H(2) C(1)–C(2)–C(3)–H(3) C(2)–C(3)–C(4)–H(4) C(3)–C(4)–C(5)–H(5ꞌ) C(3)–C(4)–C(5)–H(5) O(6)–C(1)–O(1)–H(1ꞌ) C(2)–C(3)–O(3)–H(3ꞌ) C(3)–C(4)–O(4)–H(4ꞌ)

τ0 [deg] a

111.99(18) 109.99(19) 109.89(21) 111.75(18) 111.29(25) 111.50(30) 110.13(23) 104.08(39) 108.35(39) 109.80(39) 109.60(39) 109.48(39) 110.63(39) 110.32(39) 107.61(39) 105.71(39) 106.79(39) 110.02(23) 112.72(21) 108.05(29) 111.07(27)

49.76(28) -53.38(32) 59.32(32) -51.80(33) 173.43(34) 69.16(35) 178.50(55) -174.87(55) 67.88(55) -69.44(55) -174.49(55) 175.95(55) -63.31(55) -60.99(55) -78.65(55) -86.17(55)

110.13(74) 110.59(55) 109.82(34)

b b b

110.33(47) b 113.02(46) b

b

τs [deg] a

52.7(12) -56.4(12)

111.747(81) 109.559(85) 110.107(93) 111.755(83) 111.47(11) 111.33(13) 109.43(10) 104.09(17) 108.36(17) 109.79(17) 109.56(17) 109.46(17) 110.61(17) 110.30(17) 107.58(17) 105.67(17) 106.72(17) 110.06(10) b 112.609(93) b 107.64(12) b 111.86(12) b

τ see [deg] a

49.67(12) -53.26(14) 58.93(14) -51.98(14) 172.65(15) 69.21(15) 178.54(24) -174.80(24) 67.79(24) -69.43(24) -174.55(24) 175.88(24) -63.17(24) -61.01(24) -78.67(24) -86.12(24)

562

C(3)–C(4)–C(5)–O(6) C(4)–C(5)–O(6)–C(1) O(1)–C(1)–C(2)–C(3) O(4)–C(4)–C(3)–O(3)

7 Molecules with Five Carbon Atoms

59.00(37) b -62.06(38) b 70.96(33) b -54.77(48) b

58.69(72) b -61.39(69) b

59.48(16) b -62.44(16) b 70.73(14) b -54.05(21) b

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

From the ground-state rotational constants of seven isotopic species of 3-deoxy-D-ribose (main, five 13C and 18 O) the r0 and partial rs structures were determined. The semiexperimental equilibrium structure r see was obtained from the experimental ground-state rotational constants by taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Vogt N, Demaison J, Cocinero EJ, Écija P, Lesarri A, Rudolph HD, Vogt J (2016) The equilibrium molecular structures of 2-deoxyribose and fructose by the semiexperimental mixed estimation method and coupled-cluster computations. Phys Chem Chem Phys 18(23):15555-15563

667 CAS RN: 6763-34-4 MGD RN: 393766 MW supported by ab initio calculations

α-D-Xylopyranose C5H10O5 C1 OH HO

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5)

rs [Å] 1.5225(25) 1.5014(38) 1.5159(38) 1.536(14)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5)

θs [deg] a

Dihedral angles C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5)

τs [deg] a -56.31(37) 57.5(31)

110.52(17) 109.53(28) 107.8(12)

Reproduced with permission from the PCCP Owner Societies.

a

O

a

Parenthesized uncertainties in units of the last significant digit.

HO OH

7 Molecules with Five Carbon Atoms

563

The rotational spectrum of D-xylose was recorded in a supersonic jet by a laser-ablation chirped-pulse FTMW spectrometer in the frequency region between 6 and 12 GHz. Two cyclic conformers of the pyranose form were observed. The partial rs structure of the most stable conformer was determined from the ground-state rotational constants of six isotopic species (main and five singly substituted 13C (in natural abundance)). Peña I, Mata S, Martín A, Cabezas C, Daly AM, Alonso JL (2013) Conformations of D-xylose: the pivotal role of the intramolecular hydrogen-bonding. Phys Chem Chem Phys 15(41):18243-18248

668 CAS RN: 1417801-16-1 MGD RN: 328563 GED augmented by ab initio computations

Bonds Si–C Si–Br C(2)–C(3) C(3)–C(4) C–H Bond angles C(2)–Si–C(6) C(3)–C(4)–C(5) Br–Si…X1 e H–C–H C(2)–C(3)–C(4) Si–C(2)–C(3) Dihedral angles flap(Si) g flap(C(4)) i C(2)–Si–C(6)–C(5) Si–C(6)–C(5)–C(4) C(6)–C(5)–C(4)–C(3)

1-Bromo-1-silacyclohexane C5H11BrSi Cs (axial) Cs (equatorial)

axial 1.860(2) 2.232(2) b 1.528(3) c 1.523(3) c 1.103(3) d

axial 106.2(4) 116.7(7) 124.3(6) 106.8 d,f 115.5(9) 111.0(3)

ra [Å] a equatorial

Br

2.221(2) b

θh1 [deg] a

axial

equatorial 127.6 f

τh1 [deg] a

axial 39.6(7) h 51.7(17) -42.6(8) 51.3(7) -59.6(16)

equatorial 42.8(7) h

Reproduced with permission of SNCSC [a]. Reprinted with permission. Copyright 2013 American Chemical Society [b].

a

SiH

equatorial

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ, a systematic error of 0.001r and uncertainties due to data correlation. b Difference between the Si–Br bond lengths of the axial and equatorial conformers was assumed at the value from calculation at the level of theory as indicated in the comment below. c Difference between the C–C bond lengths was assumed at the value from calculation at the level of theory as indicated in the comment below. d Average value. e X1 is a dummy atom on the bisector of the adjacent endocyclic angle. f Assumed at the value from calculation at the level of theory as indicated in the comment below. g Acute angle between the C(2)SiC(6) and C(2)C(6)C(5)C(3) planes.

564

7 Molecules with Five Carbon Atoms

h

Difference between the flap(Si) angles of the axial and equatorial conformers was assumed at the value from calculation at the level of theory as indicated in the comment below. i Acute angle between the C(3)C(4)C(5) and C(2)C(6)C(5)C(3) planes. The GED experiment was carried out at Tnozzle = 326 K. Two conformers possessing a chair conformation of the ring and the Si–Br bond in the axial and equatorial positions were detected to be present in the ratio axial : equatorial = 80(5) : 20(7) (in %), corresponding to free energy difference of 0.82(32) kcal mol-1. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from MP2_full/SDB-aug-cc-pVTZ(Br),aug-cc-pVTZ(Si,C,H) calculation. The preference of axial conformer was presented as an example for electrostatic stabilization which is unfavourable according to the steric and conjugation interaction model. a. Belyakov AV, Baskakov AA, Naraev VN, Rykov AN, Oberhammer H, Arnason I, Wallevik SO (2012) Molecular structure and conformational preferences of 1-bromo-1-silacyclohexane, CH2(CH2CH2)2SiH-Br, as studies by gas-phase electron diffraction and quantum chemistry. Russ J Phys Chem A/Zh Fiz Khim 86/86 (10/10):1563-1566 / 1665-1668 b. Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Arnason I, Belyakov AV, Kern T, Hassler K (2013) Conformational properties of 1-halogenated-1-silacyclohexanes, C5H10SiHX (X = Cl, Br, I): Gas electron diffraction, low-temperature NMR, temperature-dependent Raman spectroscopy, and quantum-chemical calculations. Organomet 32 (23):6996-7005

669 CAS RN: 18339-91-8 MGD RN: 327996 GED augmented by ab initio computations

Bonds Si–C Si–Cl C(2)–C(3) C(3)–C(4) C–H Bond angles C(2)–Si–C(6) C(3)–C(4)–C(5) Cl–Si…X d H–C–H Dihedral angles flap(Si) f flap(C4) g C(2)–Si–C(6)–C(5) Si–C(6)–C(5)–C(4) C(6)–C(5)–C(4)– C(3)

1-Chlorosilacyclohexane C5H11ClSi Cs (axial) Cs (equatorial)

ra [Å] a,b equatorial

axial 1.859(2) 2.073(2) 1 1.534(3) 2 1.529(3) 2 1.116(4) c

axial 107.7(6) 116.8(15) 126.1(15) 106.4 c,e

Cl

2.063(2) 1

axial

θh1 a

equatorial 127.5 e

τh1 [deg] a

axial 39.4(15) 54.9(12) -42.2(15) 51.6(12) -67.7(14)

SiH

equatorial 41.9(15)

Reproduced with permission of SNCSC [a]. Reprinted with permission. Copyright 2013 American Chemical Society [b].

equatorial

7 Molecules with Five Carbon Atoms

565

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 3σ and a systematic error of 0.001r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/aug-cc-pVTZ calculation. c Average value. d X is a dummy atom located on the bisector of the adjacent endocyclic angle. e Assumed at the value from computation as above. f Acute angle between the C(2)SiC(6) and C(2)C(3)C(5)C(6) planes. g Acute angle between the C(3)C(4)C(5) and C(2)C(3)C(5)C(6) planes. The GED experiment was carried out at Tnozzle = 319…327 K. The title compound was found to exist as a mixture of two conformers with the Si–Cl bonds in axial (67(5)%) and equatorial positions. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from MP2/aug-cc-pVTZ calculation. a. Belyakov AV, Baskakov AA, Naraev VN, Rykov AN, Oberhammer H, Arnason I, Wallevik SO (2011) Molecular structure and conformational preferences of 1-chloro-1-silacyclohexane, CH2(CH2CH2)2SiH-Cl, as studies by gas-phase electron diffraction and quantum chemistry. Russ J Gen Chem / Zh Obshch Khim 81/81 (11/11):2257-2261/1805-1809 b. Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Arnason I, Belyakov AV, Kern T, Hassler K (2013) Conformational properties of 1-halogenated-1-silacyclohexanes, C5H10SiHX (X = Cl, Br, I): Gas electron diffraction, low-temperature NMR, temperature-dependent Raman spectroscopy, and quantum-chemical calculations. Organomet 32 (23):6996-7005

670 CAS RN: 1363387-09-0 MGD RN: 328182 GED augmented by ab initio computations

1-Iodo-1-silacyclohexane C5H11ISi Cs (axial) Cs (equatorial)

Bonds Si–C Si–I C(2)–C(3) C(3)–C(4) C–H Si–H

ra [Å] a 1.868(5) 2.458(6) 1.535(9) b 1.528(9) b 1.090(8) c 1.478 d

Bond angles C(2)–Si–C(6) C(3)–C(4)–C(5) H–C–H C(2)–C(3)–C(4) Si–C(2)–C(3) I–Si–C(2)

θh1 [deg] a

Dihedral angles C(2)–Si–C(6)–C(5) Si–C(6)–C(5)–C(4) C(6)–C(5)–C(4)–C(3)

τh1 [deg] a

SiH

axial

105.5(10) 112.2(26) 106.8 c,e 114.1(13) 110.2(7) 109.3(10)

-42.6(27) 55.8(18) -67.4(26)

Copyright 2012 with permission from Elsevier [a].

equatorial

I

566

7 Molecules with Five Carbon Atoms

Reprinted with permission. Copyright 2010 American Chemical Society [b].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 3σ values, a systematic error of 0.001r and uncertainties due to data correlation. b Difference between the C–C bond lengths were adopted from computation at the level of theory as indicated below. c Average value. d Uncertainty was not stated. e Assumed at the value from computation at the level of theory as indicated below. The GED experiment was carried out at Tnozzle of 328 and 385 K at the short and long nozzle-to plate distances, respectively. Two conformers, characterized by the axial and equatorial positions of the Si–I bonds, were found to be present in the gas phase in amounts of 73(7) and 27(7) %, respectively. This ratio of conformers corresponds to free energy difference of 0.59(22) kcal mol-1. In each conformer, the silacyclohexane ring has a chair conformation. Structural differences between the conformers were adopted from MP2_full/SDB-aug-ccpVTZ(I),aug-cc-pVTZ(Si,C,H) calculation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from calculation at the level of theory as indicated above. The full set of structural parameters was given for axial conformer only. The ra(Si–I) bond length for equatorial conformer was determined to be 2.447(6) Å. The preference of axial conformer was presented as an example for electrostatic stabilization which is unfavourable according to the steric and conjugation interaction model. a. Belyakov AV, Baskakov AA, Berger RJF, Mitzel NW, Oberhammer H, Arnason I, Wallevik SÒ (2012) Molecular structure and conformational preferences of gaseous 1-iodo-1-silacyclohexane. J Mol Struct 1012:126-130 b. Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Arnason I, Belyakov AV, Kern T, Hassler K (2013) Conformational properties of 1-halogenated-1-silacyclohexanes, C5H10SiHX (X = Cl, Br, I): Gas electron diffraction, low-temperature NMR, temperature-dependent Raman spectroscopy, and quantum-chemical calculations. Organomet 32 (23):6996-7005

671 CAS RN: 1003-03-8 MGD RN: 415529 MW augmented by QC calculations

Cyclopentanamine Cyclopentylamine C5H11N Cs NH2 a

Bonds C(1)–N C(1)–C(2) C(2)–C(3) C(3)–C N–H C(1)–H C(2)–H(1) C(2)–H(2) C(3)–H(1) C(3)–H(2)

r0 [Å] 1.470(3) 1.529(3) 1.544(3) 1.550(3) 1.016(3) 1.100(2) 1.095(2) 1.096(2) 1.092(2) 1.094(2)

Bond angles C(2)–C(1)–N C(2)–C(1)–C C(3)–C(2)–C(1) C(2)–C(3)–C C(1)–N–H

θ0 [deg] a 108.7(5) 101.4(5) 104.3(5) 105.3(5) 110.3(5)

7 Molecules with Five Carbon Atoms

H–N–H H–C(1)–N H–C(1)–C(2) H(1)–C(2)–C(1) H(1)–C(2)–C(3) H(2)–C(2)–C(1) H(2)–C(2)–C(3) H(1)–C(2)–H(2) H(1)–C(3)–C(2) H(1)–C(3)–C H(2)–C(3)–C(2) H(2)–C(3)–C H(1)–C(3)–H(2)

106.9(5) 113.2(5) 112.0(5) 112.6(5) 111.9(5) 108.7(5) 111.6(5) 107.7(5) 110.1(5) 110.6(5) 111.3(5) 111.7(5) 107.7(5)

Dihedral angles C(2)–C(1)–C(2)–C(3) H–N–C(1)–C(2) H–N–C(1)–H

τ0 [deg] a

567

42.0(5) 66.3(5) 58.9(5)

Copyright © 2014 John Wiley & Sons, Ltd. Reproduced with permission.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the region between 10.8 and 15.8 GHz. Only one conformer, anti-axial, was identified. This conformer was found to be the most stable one in comparison to three other conformers, which were detected by temperature-dependent Raman vibrational spectroscopy. The percentage of the anti-axial conformer was estimated to be 53 % (at ambient temperature). The r0 structure was determined by adjusting the MP2_full/6-311+G(d,p) structure to the observed ground-state rotational constants of the main species. Darkhalil ID, Klaassen JJ, Nagels N, Herrebout WA, van der Veken BJ, Gurusinghe RM, Tubergen MJ, Durig JR (2014) Raman and infrared, microwave spectra, conformational stability, adjusted r0 structural parameters, and vibrational assignments of cyclopentylamine. J Raman Spectrosc 45(5):392-406

672 CAS RN: 110-89-4 MGD RN: 404607 MW supported by ab initio calculations Bonds a N–H N–C(2) C(2)–C(3) C(3)–C(4) C(2)–H(x) C(2)–H(q) C(3)–H(x) C(3)–H(q) C(4)–H(x) C(4)–H(q)

Piperidine C5H11N Cs

r see [Å] b 1.0116(3) 1.4589(2) 1.5212(2) 1.5255(2) 1.1020(5) 1.0897(5) 1.0918(5) 1.0909(5) 1.0943(5) 1.0906(5)

N H

568

7 Molecules with Five Carbon Atoms

Bond angles a H–N–C(2) C(2)–N–C(6) N–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) N–C(2)–H(x) N–C(2)–H(q) C(3)–C(2)–H(x) C(3)–C(2)–H(q) C(2)–C(3)–H(x) C(2)–C(3)–H(q) C(4)–C(3)–H(x) C(4)–C(3)–H(q) C(3)–C(4)–H(x) C(3)–C(4)–H(q) H(x)–C(4)–H(q)

θ see [deg] b

Dihedral angles a H–N–C(2)–C(3) N–C(2)–C(3)–C(4) H–N–C(2)–H(x) H–N–C(2)–H(q) C(6)–N–C(2)–H(x) C(6)–N–C(2)–H(q) N–C(2)–C(3)–H(x) N–C(2)–C(3)–H(q) C(5)–C(4)–C(3)–H(q) C(2)–C(3)–C(4)–H(x) C(2)–C(3)–C(4)–H(q)

τ see [deg] b

109.70(3) 111.34(2) 109.37(2) 110.31(2) 110.57(2) 111.91(9) 108.63(8) 108.67(12) 110.54(8) 108.56(12) 109.87(8) 109.64(9) 110.86(8) 109.02(4) 1109.62(4) 106.91(11)

175.38(7) 57.44(2) –64.15(13) -54.65(10) 57.48(12) 176.28(8) -62.72(8) -179.95(9) -175.43(8) 66.33(8) -176.39(9)

Reprinted with permission. Copyright 2014 American Chemical Society.

a b

H(x) and H(q) are axial and equatorial H atoms, respectively. Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of piperidine was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 18 GHz. The semiexperimental equilibrium structure r see was determined from the experimental ground-state rotational constants of six isotopic species (main, three 13C, 15N and D) using rovibrational corrections calculated with the MP2/wCVQZ quadratic and cubic force constants. The equilibrium structure is fitted by the mixed estimation method. Demaison J, Craig NC, Groner P, Écija P, Cocinero EJ, Lesarri A, Rudolph HD (2015) Accurate equilibrium structures for piperidine and cyclohexane. J Phys Chem A 119(9):1486-1493

673 CAS RN: 926-42-1 MGD RN: 370593 GED augmented by ab initio computations

2,2-Dimethyl-1-propanol 1-nitrate

H 3C H 3C

Bonds

rh1 [Å] a

CH3

C5H11NO3 Cs O

O N O

7 Molecules with Five Carbon Atoms

C–C C–C(m) c C(1)–C(2) C–O N–O(3) N=O N=O(2) N=O(1) C–H

1.538(1) b 1.539(1) d 1.535(3) d 1.441(3) e 1.408(2) e 1.210(1) b 1.213(2) f 1.208(2) f 1.114(2) b

Bond angles C(m)–C–C(m) c C–C–O(3) C–O–N O(1)=N=O(2) H–C–H

θh1 [deg] a

Other angle tilt [C(CH3)3] h

τh1 [deg] a

569

108.7(2) 106.9(3) 113.2(3) 128.7(6) 110.8(1) g

3.7(2) g

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit are 1σ values. Average value. c C(m) is carbon atom in the methyl group. d Difference between the C–C(m) and C(1)–C(2) bond lengths was restrained to ab initio value. e Difference between the C–O and N–O bond lengths was restrained as above. f Difference between the N=O bond lengths was restrained as above. g Restrained as above. h Defined as a decrease in the C(1)–C(2)–C(3) angle with respect to that required for C3v symmetry. b

The GED experiment was carried out at room temperature. Local C3v symmetry for the C(CH3)3 group and each of the CH3 groups as well as overall Cs symmetry were assumed. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated with quadratic force constants from MP2/TZVPP computation. Evangelisti C, Klapötke TM, Krumm B, Nieder A, Berger RJF, Hayes SA, Mitzel NW, Troegel D, Tacke R (2010) Sila-substitution of alkyl nitrates: Synthesis, structural characterization, and sensitivity studies of highly explosive (nitratomethyl)-, bis(nitratomethyl)-, and tris(nitratomethyl)silanes and their corresponding carbon analogues. Inorg Chem 49 (11):4865-4880

674 CAS RN: MGD RN: 543195 MW augmented by DFT calculations

Distance O…C(1) Angle

r0 [Å] a 2.960(2)

θ0 [deg] a

2-Methyl-2-propanol – difluoromethane (1/1) tert-Butanol – difluoromethane (1/1) C5H12F2O Cs H3C

H 3C

CH3

OH

H

F

H

F

570

O…C(1)–F(1)

7 Molecules with Five Carbon Atoms

73.7(1)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectrum of the complex of tert-butanol with difluoromethane was recorded by a pulsed-jet FTMW spectrometer n the frequency region between 6.5 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of the main isotopic species; the remaining structural parameters were assumed at the vibrationally averaged values from the calculations at the B2LYP-D3 level of theory in conjunction with m-aug-cc-pVTZ basis set, in which d-functions on H atoms were removed. The complex is stabilized by three hydrogen bonds. Spada L, Tasinato N, Bosi G, Vazart F, Barone V, Puzzarini C (2017) On the competition between weak OH⋅⋅⋅F and C–H⋅⋅⋅F hydrogen bonds, in cooperation with C-H⋅⋅⋅O contacts, in the difluoromethane - tert-butyl alcohol cluster. J Mol Spectrosc 337(1):90-95

675 CAS RN: 16849-81-3 MGD RN: 386068 GED combined with MS and augmented by ab initio computations

Bonds N(2)=C(4) N(1)–C(4) N(3)–C(4) N(2)–N(5) N(1)–C(8) N(1)–C(9) N(3)–C(10) N(3)–C(11) N(5)=O(6) N(5)=O(7) H...O(6)

re [Å] a,b 1.307(15) 1.370(8) 1 1.378(8) 1 1.376(5) 1.445(3) 2 1.445(3) 2 1.446(3) 2 1.444(3) 2 1.225(4) 3 1.215(4) 3 2.32(2) c

Bond angles N(2)=C(4)–N(1) N(2)=C(4)–N(3) N(1)–C(4)–N(3) C(4)=N(2)–N(5) C(4)–N(1)–C(8) C(4)–N(1)–C(9) C(8)–N(1)–C(9) C(4)–N(3)–C(10) C(4)–N(3)–C(11) C(10)–N(3)–C(11) N(2)–N(5)=O(6) N(2)–N(5)=O(7) O(6)–N(5)=O(7)

θe [deg] a,b

117.6(5) 4 126.4(5) 4 115.9(10) 114.6(9) 117.2(8) 5 120.1(8) 5 116.8(15) 6 118.4(8) 5 118.8(8) 5 116.4(15) 6 119.6(4) 7 117.2(4) 7 123.0(8)

N,N,N’,N’-Tetramethyl-N’-nitroguanidine C5H12N4O2

N H 3C

NO2

N

N

CH3

CH3

C1

CH3

7 Molecules with Five Carbon Atoms

C(11)–H…O(6)

106.8c

Dihedral angles β1 d β2 e β3 f β4 g

τe [deg]

571

3.5 c 23.6 c -25.0 c -4.0 c

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from computation at the level of theory as indicated below. c Dependent parameter. d Angle between the C(4)=N(2) bond and the N(1)C(4)N(3) plane. e Angle between the N(1)–C(4) bond and the C(8)N(1)C(9) plane. f Angle between the N(3)–C(4) bond and the C(10)N(3)C(11) plane. g Angle between the N(5)–N(2) bond and the O(6)N(5)O(7) plane. b

The synchronous GED/MS experiment was carried out at 373 K. Decomposition products were not detected. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with the MP2_full/6-311G(3df,2p) quadratic and cubic force constants taking into account non-linear kinematic effects. Large-amplitude motion of the nitro group around the N–N bond was described by a dynamic model adopting the PEF from MP2_full/6-311G(3d,p) calculation. Khaikin LS, Grikina OE, Girichev GV, Kovacs A, Dyugaev KP, Astachov AM (2011) The geometry of the nitroguanyl fragment in the simplest nitroguanidine derivatives in the absence of intermolecular interactions: The gas electron diffraction data on 1,1,3,3-tetramethyl-2-nitroguanidine. Russ J Phys Chem A / Zh Fiz Khim 85 / 85 (3 / 3):441-446 / 508-513

676 CAS RN: 1827625-37-5 MGD RN: 467970 GED combined with MS and augmented by ab initio computations

3-Methyl-1-oxa-3-silacyclohexane 3-Methyl-3-silatetrahydropyran C5H12OSi C1 (equatorial) C1 (axial) H Si

Bonds O(1)–C(2) C(2)–Si(3) Si(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–O(1) Si(3)–H Si(3)–C(7)

rh1 [Å] a 1.441(3) 1.895(4) 1.881(4) 1.541(4) 1.529(4) 1.422(3) 1.483 b 1.876(4)

Bond angles O(1)–C(2)–Si(3) C(2)–Si(3)–C(4) Si(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–O(1) C(6)–O(1)–C(2)

θh1 [deg] c 109.9(5) 101.9(9) 110.4(5) 111.8(5) 115.4(8) 113.2(8)

O

CH3

572

7 Molecules with Five Carbon Atoms

C(2)–Si(3)–C(7) H–Si(3)–C(7)

112.6(9) 107.6 d

Dihedral angles O(1)–C(2)–Si(3)–C(4) C(2)–Si(3)–C(4)–C(5) Si(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–O(1) C(5)–C(6)–O(1)–C(2) C(6)–O(1)–C(2)–Si(3)

τh1 [deg] c 47.4(22) -43.6(24) -52.5(19) 65.6(22) -71.8(14) 62.1(11)

Reprinted with permission. Copyright 2015 American Chemical Society.

equatorial

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Fixed at the value from MP2/6-311G**computation. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Dependent parameter. The GED experiment was carried out at Tnozzle = 286(5) K. Two conformers with the methyl group in the axial and equatorial positions with respect to the ring were found to be present in amounts of 54(9) and 46(9) %, respectively. The determined structural parameters were given for the equatorial conformer. Geometry of the axial conformer was estimated to be very close to that of the equatorial conformer. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from computation at the level of theory as indicated above. Shainyan BA, Kirpichenko SV, Chipanina NN, Oznobikhina LP, Kleinpeter E, Shlykov SA, Osadchiy DY (2015) Synthesis and conformational analysis of 3-methyl-3-silatetrahydropyran by GED, FTIR, NMR, and theoretical calculations: Comparative analysis of 1-hetero-3-methyl-3-silacyclohexanes. J Org Chem 80 (24):12492-12500

677 CAS RN: 2158326-24-8 MGD RN: 545674 MW augmented by ab initio calculations

Distance O(1)…O(2)

r0 [Å] a 3.08(2)

Angle C=O(1)…O(2)

θ0 [deg] a 102.2(4)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainty in units of the last significant digit.

2-Propanone – ethanol (1/1) Acetone – ethanol (1/1) C5H12O2 C1 O

H 3C H 3C

CH3

OH

7 Molecules with Five Carbon Atoms

573

The rotational spectrum of the complex was recorded by a pulsed-jet FTMW spectrometer in the frequency range between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D); the remaining structural parameters were fixed to the MP2/aug-cc-pVTZ values. The barriers to internal rotations of the two methyl groups of acetone were determined to be 252(4) and 220(1) cm-1. The complex subunits are linked by the O–H…O and weak C–H…O hydrogen bonds. Gou Q, Favero LB, Feng G, Evangelisti L, Pérez C, Caminati W (2017) Interactions between ketones and alcohols: Rotational spectrum and internal dynamics of the acetone-ethanol complex. Chem Eur J 23(46):1111911125

678 CAS RN: 1220533-35-6 MGD RN: 467803 GED combined with MS and augmented by ab initio computations

Bonds S–C(2) S–C(6) Si–C(2) Si–C(4) C(4)–C(5) C(5)–C(6) Si–C(7) H–Si C–H Bond angles C(2)–Si–C(4) S–C(2)–Si C(6)–S–C(2) S–C(6)–C(5) C(4)–C(5)–C(6) C(7)–Si–C(4) H–C(4)–Si H–C(4)–C H–C(4)–H H–C(7)–H Dihedral angles S–C(2)–Si–C(4) C(6)–S–C(2)–Si C(5)–C(6)…C(4)…S Hʹ–C(7)–Si–C(4) Flap(C(5)) Flap(Si) Flap(S)

3-Methyl-1-thia-3-silacyclohexane 3-Methyl-3-silathiane C5H12SSi C1 (axial) C1 (equatorial)

rh1 [Å] a equatorial 1.826(5) 1.819(5) 1.881(4) 1.880(4) 1.534(3) 1.525(3) 1.874(4) 1.483 b 1.111(2) c

axial 1.827(5) 1.819(5) 1.881(4) 1.880(4) 1.534(3) 1.525(3) 1.874(4) 1.486 b 1.111(2) c

H Si

CH3

S

axial

θh1 [deg] d

axial 104.9(13) 111.1(3) 102.0(18) 116.6 e 114.0 e 110.8(7) 109.9(4) 109.3(4) 104.3(15) 104.1(15)

equatorial 104.9(13) 111.1(4) 102.0(18) 116.7 e 114.0 e 110.8(7) 108.3(4) 108.9(4) 104.3(15) 104.2(15)

τh1 [deg] d

axial -51.6(21) 55.3(41) 124.4(9) -75(13) 55.4 e,f 42.3 e,g 52.3 e,h

Copyright 2015 with permission from Elsevier.

equatorial 51.6(22) -55.4(32) -124.4(10) 72(35) 55.4 e,f 44.2 e,g 52.3 e,h

equatorial

574

7 Molecules with Five Carbon Atoms

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Assumed at the value from computation at the level of theory as indicated below. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Dependent parameter. f Flap angle between the C(4)C(5)C(6) and C(4)C(6)S planes. g Flap angle between the C(2)SiC(4) and C(2)C(4)C(5) planes. h Flap angle between the C(2)C(6)S and C(5)C(6)C(2) planes. The GED experiment was carried out at Tnozzle = 270(5) K. Two conformers with the methyl groups in the axial and equatorial positions with respect to the ring were found in the gas phase in amounts of 59(5) and 41(5) %, respectively. Approximately the same ratio of the conformers was determined by FTIR and Raman spectroscopy in the gas phase and solution. The results of the FTIR study indicated the increase of amount of the equatorial conformer at lowering the temperature. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from MP2/6-311G** computation. Shlykov SA, Osadchiy DY, Chipanina NN, Oznobikhina LP, Shainyan BA (2015) Molecular structure and conformational analysis of 3-methyl-3-silathiane by gas phase electron diffraction, FTIR spectroscopy and quantum chemical calculations. J Mol Struct 1100:555-561

Dimethyl[2-(methoxy-κO)ethanolato-κO]gallium

679 CAS RN: 1360872-59-8 MGD RN: 382008 GED augmented by QC computations

C5H13GaO2 C1 CH3 CH3

O

Bonds Ga–O(4) Ga–C O(4)–C(5) C(5)–C(6) C(6)–O(7) O(7)–C(8) Ga...O(7) C–H

rh1 [Å] a 1.865(10) b,c 1.971(6) b,c,d 1.437(7) e 1.552(8) e 1.476(7) e 1.461(7) e 2.160(20) 1.099(7) b,c,d

Bond angles O(4)–Ga–C(2) O(4)–Ga–C(3) Ga–O(4)–C(5) O(4)–C(5)–C(6) C(5)–C(6)–O(7) C(6)–O(7)–C(8) Ga–C(2)–H H–C(5)–H H–C(6)–H O–C(8)–H

θh1 [deg] a

Dihedral angles Ga–O(4)–C(5)–C(6)

τh1 [deg] a

112.2(19) f 108.9(20) f 114.3(9) b 108.4(11) b 104.4(11) b 112.3(12) b,c 109.7(23) b,c,d 107.2(25) b,c 108.9(25) b,c 109.5(25) b,c,d

54.4(26) b

Ga O

CH3

7 Molecules with Five Carbon Atoms

O(4)–C(5)–C(6)–O(7) C(2)–Ga–O(4)–C(5) C(3)–Ga–O(4)–C(5) C(5)–C(6)–O(7)–C(8)

575

-36.4(28) b 65.9(28) b,c -132.0(33) b,c 133.5(28) b,c

Reprinted with permission. Copyright 2012 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Independent parameter. c Restrained to the value from MP2_full/6-311+G* calculation. d Average value. e Differences between the C–O and C–C bond lengths were restrained to the values from computation as indicated above. f Difference between the O(4)–Ga–C bond angles was restrained to the value from computation as indicated above. b

Only monomeric molecules of the title compound were observed in the gas phase at the temperature of the experiment (Tnozzle = 390 K). The molecule possesses a five-membered ring formed by a dative bond between Ga and the donor oxygen atom. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using the B3LYP/6-311+G* quadratic force field. Knapp CE, Wann DA, Bil A, Schirlin JT, Robertson HE, McMillan PF, Rankin DWH, Carmalt CJ (2012) Dimethylalkoxygallanes: Monomeric versus dimeric gas-phase structures. Inorg Chem 51 (5):3324-3331

680 CAS RN: MGD RN: 213679 MW augmented by ab initio calculations

2-Propanol – oxybismethane (1/1) Isopropanol – dimethyl ether (1/1) C5H14O2 C1 OH

O

Distances O(5)…H(5) C(2)–C(1) C(3)–C(1) C(1)–O(4) O(4)–H(5) C(1)–H(6) C(3)–H(1) C(3)–H(1ꞌ) C(3)–H(2) C(2)–H(3) C(2)–H(3ꞌ) C(2)–H(4) C(6)–O(5) C(7)–O(5) H(7)–C(6) H(7ꞌ)–C(6) H(8)–C(6) H(9)–C(7) H(9ꞌ)–C(7) H(10)–C(7)

r0 [Å] a 1.917 1.525 b 1.519 b 1.424 b 0.970 b 1.102 b 1.094 b 1.093 b 1.094 b 1.095 b 1.095 b 1.095 b 1.418 b 1.418 b 1.091 b 1.098 b 1.098 b 1.090 b 1.098 b 1.098 b

Angles

θ0 [deg] a

H 3C

CH3

H 3C

CH3

576

7 Molecules with Five Carbon Atoms

C(6)–O(5)…H(5) C(3)–C(1)–C(2) O(4)–C(1)–C(3) H(5)–O(4)–C(1) H(6)–C(1)–O(4) H(1)–C(3)–C(1) H(1ꞌ)–C(3)–C(1) H(2)–C(3)–C(1) H(3)–C(2)–C(1) H(3ꞌ)–C(2)–C(1) H(4)–C(2)–C(1) O(5)…H(5)–O(4) C(7)–O(5)–C(6) H(7)–C(6)–O(5) H(7ꞌ)–C(6)–O(5) H(8)–C(6)–O(5) H(9)–C(7)–O(5) H(9ꞌ)–C(7)–O(5) H(10)–C(6)–O(5)

115.9 112.0 b 106.8 b 107.0 b 109.6 b 110.7 b 110.3 b 109.7 b 110.9 b 109.6 b 110.5 b 178.5 b 111.5 b 107.2 b 110.9 b 110.7 b 107.2 b 110.9 b 110.7 b

Dihedral angles O(4)–C(1)–C(3)–C(2) H(5)–O(4)–C(1)–C(2) H(6)–C(1)–O(4)–H(5) H(1)–C(3)–C(1)–C(2) H(1ꞌ)–C(3)–C(1)–C(2) H(2)–C(3)–C(1)–C(2) H(3)–C(2)–C(1)–C(3) H(3ꞌ)–C(2)–C(1)–C(3) H(4)–C(2)–C(1)–C(3) O(5)…H(5)–O(4)–C(1) C(6)–O(5)…H(5)–O(4) C(7)–O(5)–C(6)–H(5) H(7)–C(6)–O(5)–C(7) H(7ꞌ)–C(6)–O(5)–C(7) H(8)–C(6)–O(5)–C(7) H(9)–C(7)–O(5)–C(6) H(9ꞌ)–C(7)–O(5)–C(6) H(10)–C(7)–O(5)–C(6)

τe [deg]

-121.6 b 54.7 b -65.3 b -60.5 b 179.0 b 59.6 b 60.9 b -59.3 b -179.1 b -107.0 b -5.1 b 134.0 b 179.2 b 59.8 b -61.5 b -179.2 b -59.8 b 61.5 b

Reprinted with permission. Copyright 2011 American Chemical Society.

a b

Uncertainty was not given in the original paper. MP2/6-311++G** value.

The rotational spectrum of the binary complex of isopropanol with dimethyl ether was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 7 and 16.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species (main and two D); the remaining structural parameters were assumed at the values from ab initio calculation (see above). The complex is formed by a hydrogen bond between the hydrogen atom of the hydroxyl group and the oxygen atom in the ether subunit. The shrinkage of the O…O distance due to the deuteration of the hydroxylic group by about 0.007 Å is associated with the Ubbelohde effect. Evangelisti L, Pesci F, Caminati W. (2011) Adducts of alcohols with ethers: The rotational spectrum of isopropanol-dimethyl ether. J Phys Chem A 115(34) 9510-9513

7 Molecules with Five Carbon Atoms

577

681 CAS RN: 1196036-32-4 MGD RN: 211281 GED augmented by QC computations

Bonds Si–C Si–Si C(2)–C(3) C(3)–C(4) C–H Si–H Bond angles Si–Si–H C(2)–Si–C(6) C(3)–C(4)–C(5) Si–Si…X d H–C–H Dihedral angles flap(Si) f flap(C4) g

1-Silylsilacyclohexane C5H14Si2 Cs (axial) Cs (equatorial)

ra [Å] a,b axial equatorial 1.872(2) c 1.872(2) c 1 2.348(3) 2.343(3) 1 2,c 1.548(3) 1.548(3) c 2,c 1.541(3) 1.541(3) c 1.102(2) c 1.102(2) c c 1.482(7) 1.482(7) c

SiH

SiH3

θh1 [deg] a

axial 108.8 c 103.7(4) c 111.1(8) c 132.1(15) 106.4 c,e

equatorial 108.8 c 103.7(4) c 111.1(8) c 127.0(17) 106.4 c,e

axial

τh1 [deg] a,b

axial 41.4(16) 3 59.6(7) c

equatorial 41.6(16) 3 59.6(7) c

Reprinted with permission. Copyright 2010 American Chemical Society.

equatorial Parenthesized uncertainties in units of the last significant digit are 3σ values. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/cc-pVTZ computation. c Average value for both conformers. d X is a dummy atom on the bisector of the adjacent endocyclic angle. e Assumed value. f Acute angle between the C(2)C(3)C(5)C(6) and C(2)Si(1)C(6) planes. g Acute angle between the C(2)C(3)C(5)C(6) and C(3)C(4)C(5) planes. a

The GED experiment was carried out at Tnozzle ≈ 330 K. The title compound was found to exist as a mixture of two conformers, characterized by the axial and equatorial positions of the SiH3 group with respect to the ring. The ratio of the conformers was determined to be axial : equatorial = 57(7) : 43(7) (in %), corresponding to free energy difference Gaxial − Gequatorial = -0.17(15) kcal mol−1. Thus, the silyl group in the title molecule shows no preference for the equatorial position being contrary to that found for silylcyclohexane. The overall Cs symmetry and a chair conformation of the ring were assumed. Vibrational corrections to experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from MP2 computation. Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Arnason I, Belyakov AV, Baskakov AA, Hassler K, Oberhammer H (2010) Conformational properties of 1-silyl-1-silacyclohexane, C5H10SiHSiH3: Gas electron diffraction, low-temperature NMR, temperature-dependent Raman spectroscopy, and quantum chemical calculations. J Phys Chem A 114 (5):2127-2135

578

7 Molecules with Five Carbon Atoms

682 CAS RN: 1428376-79-7 MGD RN: 516330 GED augmented by QC computations

1,3-Dimethyl-1-aza-3-silacyclohexane 1,3-Dimethyl-3-silapiperidine C5H15NSi C1 (axial) C1 (equatorial)

Bonds Si–C(m) Si–H Si–C(2) N–C(2) N–C(6) C(5)–C(6) C(4)–C(5) Si–C(4) N–C(m)

rh1 [Å] a,b 1.881(4) 1.490 c 1.893(4) 1.472(4) 1.469(4) 1.534(8) 1.542(8) 1.882(4) 1.460(4)

Bond angles C(m)–Si–H N–C(2)–Si C(2)–Si–C(4) Si–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–N C(6)–N–C(2) Σ(CNC) d

θh1 [deg] a,b

Dihedral angles N–C(2)–Si–C(4) C(2)–Si–C(4)–C(5) Si–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–N C(5)–C(6)–N–C(2) C(6)–N–C(2)–Si C(5)–C(4)–Si–C(m) Hʹ–C(m)–Si–C(2)

axial

112.5(17) 109.6(4) 103.1(7) 110.7(7) 114.8(11) 112.2(7) 114.4(14) 335.8(17)

τh1 [deg] a,b

axial -45.6(22) 41.1(21) -51.7(25) 64.2(21) -70.8(12) 62.4(18) -75.2(22) 65.2 c

equatorial

equatorial -45.6(22) 41.1(21) -51.7(25) 64.2(21) -70.8(12) 62.4(18) 157.3(25) 178.7 c

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Estimated total errors are given in parentheses in units of the last significant digit. Structural parameters of the axial conformer were assumed to be equal to those of the equatorial conformer, except for the C(5)–C(4)–Si–C(m) and H(a)–C(m)–Si–C(2) torsional angles. c Assumed at the value from computation at the level of theory as indicated below. d Sum of the bond angles around the N atom. b

The GED experiment was carried out at Tnozzle= 293(5) K. The title compound was found to exist as a mixture of two conformers possessing a chair conformation of the ring with the equatorial N-methyl group and differing by axial or equatorial position of the methyl group at the Si atom. The amounts of the axial and equatorial conformers were refined to be 65(7) and 35(7) %, respectively; the corresponding free energy difference is 0.36(18) kcal mol-1. Approximately the same ratio of the conformers was determined by FTIR vibrational spectroscopy in the gas phase at room temperature (62(5) and 38(5)%, respectively).

7 Molecules with Five Carbon Atoms

579

In the GED analysis, vibrational corrections to experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Shainyan BA, Kirpichenko SV, Kleinpeter E, Shlykov SA, Osadchiy DY, Chipanina NN, Oznobikhina LP (2013) 1,3-Dimethyl-3-silapiperidine: Synthesis, molecular structure, and conformational analysis by gas-phase electron diffraction, low temperature NMR, IR and Raman spectroscopy, and quantum chemical calculations. J Org Chem 78 (8):3939-3947

580

7 Molecules with Five Carbon Atoms

References: 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624

625 626 627

628 629

Long BE, Arsenault EA, Obenchain DA, Choi YJ, Ocola EJ, Laane J, Pringle WC, Cooke SA (2016) Microwave spectra, structure, and ring-puckering vibration of octafluorocyclopentene. J Phys Chem A 120(43):8686-8690 Fournier JA, Bohn RK, Montgomery JA, Onda M (2010) Helical C2 structure of perfluoropentane and the C2v structure of perfluoropropane. J Phys Chem A 114(2):1118-1122 Calabrese C, Gou Q, Maris A, Caminati W, Melandri S (2016) Probing the lone pair⋅⋅⋅π-hole interaction in perfluorinated heteroaromatic rings: The rotational spectrum of pentafluoropyridine⋅water. J Phys Chem Lett 7(8):1513-1517 Evangelisti L, Tang S, Velino B, Giuliano BM, Melandri S, Caminati W. (2009) Hexafluoroacetylacetone: A 'rigid' molecule with an enolic Cs shape. Chem Phys Lett 473(46):247-250 Duong CH, Obenchain DA, Cooke SA, Novick SE (2016) Rotational spectroscopy of 2H,3Hperfluoropentane. J Mol Spectrosc 324(6):53-55 Sun M, Kamaee M, van Wijngaarden J (2014) Microwave spectroscopic investigation and structural determination of the Ar-difluoropyridine van der Waals complexes. J Phys Chem A 118(38):8730-8736 See 606. See 606. See 606. See 606. van Dijk CW, Sun M, van Wijngaarden J (2012) Investigation of structural trends in difluoropyridine rings using chirped-pulse Fourier transform microwave spectroscopy and ab initio calculations. J Mol Spectrosc 280:34-41 See 611. See 611. See 611. See 611. Frogner M, Hedberg K, Hedberg L, Lunelli B (2010) Molecular structure and conformations of 1-methoxy-2,3,3,4,4-pentafluorocyclobut-1-ene. J Mol Struct 978 (1-3):294-298 Sun M, Kamaee M, van Wijngaarden J (2013) Rotational spectra and structures of the van der Waals dimers of argon with 2-fluoropyridine and 3-fluoropyridine. J Phys Chem A 117(50):13429-13434 See 617. Calabrese C, Maris A, Uriarte I, Cocinero EJ, Melandri S (2017) Effects of chlorination on the tautomeric equilibrium of 2-hydroxypyridine: Experiment and theory. Chem Eur J 23(15):3595-3604 See 619. See 619. van Dijk CW, Sun M, van Wijngaarden J (2012) Microwave rotational spectra and structures of 2-fluoropyridine and 3-fluoropyridine. J Phys Chem A 116(16):4082-4088 See 622. Kidwell NM, Vaquero-Vara V, Ormond TK, Buckingham GT, Zhang D, Mehta-Hurt DN, McCaslin L, Nimlos MR, Daily JW, Dian BC, Stanton JF, Ellison GB, Zwier TS (2014) Chirped-pulse Fourier transform microwave spectroscopy coupled with a flash pyrolysis microreactor: structural determination of the reactive intermediate cyclopentadienone. J Phys Chem Lett 5(13):2201-2207 Norooz Oliaee J, McKellar ARW, Moazzen-Ahmadi N (2011) Observation of a planar isomer of the OCS-(C2H2)2 trimer. Chem Phys Lett 512(4-6):167-171 Melandri S, Giuliano BM, Maris A, Evangelisti L, Velino B, Caminati W (2009) Rotational spectrum of the mixed van der Waals triad pyridine-Ar-Ne. ChemPhysChem 10(14):2503-2507 Tanjaroon C, Daly AM, Kukolich SG (2008) The rotational spectrum and structure for the argon-cyclopentadienyl thallium van der Waals complex: Experimental and computational studies of noncovalent bonding in an organometallic π-complex. J Chem Phys 129(5):054305/1-054305/8 Gou Q, Feng G, Evangelisti L, Caminati W (2013) Rotational study of cis- and trans-acrylic acid-trifluoroacetic acid. J Phys Chem A 117(50):13500-13503 (a) See 611.

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(b) Császár AG, Demaison J, Rudolph HD (2015) Equilibrium structures of three-, four-, five-, six-, and seven-membered unsaturated N-containing heterocycles. J Phys Chem A 119(9):1731-1746 Evangelisti L, Favero LB, Giuliano BM, Tang S, Melandri S, Caminati W (2009) Microwave spectrum of [1,1]-pyridine-Ne2. J Phys Chem A 113:14227-14230 Daly AM, Mitchell EG, Sanchez DA, Block E., Kukolich SG (2011) Microwave spectra and gas phase structural parameters for N-hydroxypyridine-2(1H)-thione. J Phys Chem A 115(50):14526-14530 Pejlovas AM, Kukolich SG (2016) Rotational spectra and gas phase structure of the maleimide – formic acid doubly hydrogen bonded dimer. J Mol Spectrosc 321(3):1-4 Tikhonov DS, Vishnevskiy YV, Rykov AN, Grikina OE, Khaikin LS (2017) Semiexperimental equilibrium structure of pyrazinamide from gas-phase electron diffraction. How much experimental is it? J Mol Struct 1132:20-27 Vogt N, Dorofeeva OV, Sipachev VA, Rykov AN (2009) Molecular structure of 9H-adenine tautomer: Gas-phase electron diffraction and quantum-chemical studies. J Phys Chem A 113 (49):13816-13823 Gahlmann A, Park ST, Zewail AH (2009) Structure of isolated biomolecules by electron diffraction-laser desorption: Uracil and guanine. J Am Chem Soc 131 (8):2806-2808 Kirkpatrick R, Masiello T, Martin M, Nibler JW, Maki A, Weber A, Blake TA (2012) Highresolution infrared studies of the ν10, ν11, ν14, and ν18 levels of [1.1.1]propellane. J Mol Spectrosc. 281:51-62 Gou Q, Spada L, Vallejo-Lopez M, Melandri S, Lesarri A, Cocinero EJ, Caminati W (2016) Intermolecular hydrogen bonding in 2-fluoropyridine-water. ChemistrySelect 1(6):1273-1277 Calabrese C, Gou Q, Spada L, Maris A, Caminati W, Melandri S (2016) Effects of fluorine substitution on the microsolvation of aromatic azines: The microwave spectrum of 3fluoropyridine-water. J Phys Chem A 120(27):5163-5168 Vogt N, Marochkin II, Rykov AN, Dorofeeva OV (2013) Interplay of experiment and theory: Determination of an accurate equilibrium structure of 1-methyluracil by the gas electron diffraction method and coupled-cluster computations. J Phys Chem A 117 (44):11374-11381 Vogt N, Demaison J, Ksenafontov DN, Rudolph HD (2014) A benchmark study of molecular structure by experimental and theoretical methods: Equilibrium structure of thymine from microwave rotational constants and coupled-cluster computations. J Mol Struct 1076:483-489 Klaassen JJ, Darkhalil ID, Deodhar BS, Gounev TK, Gurusinghe RM, Tubergen MJ, Groner P, Durig JR (2013) Microwave and infrared spectra, adjusted r0 structural parameters, conformational stabilities, vibrational assignments, and theoretical calculations of cyclobutylcarboxylic acid chloride. J Phys Chem A 117(30):6508-6524 Durig JR, Ganguly A, Klaassen JJ, Guirgis GA (2009) The r0 structural parameters, conformational stability, and vibrational assignment of equatorial and axial cyanocyclobutane. J Mol Struct 923(1-3):28-38 See 642. (a) Hirota E, Watanabe R, Kawashima Y, Shigemune T, Matsumoto J, Murakami K, Mizoguchi A, Kanamori H, Nakajima M, Endo Y, Sumiyoshi Y (2013) Microwave studies on 1,4-pentadiene: CH2=CH-CH2-CH=CH2; transformations among the three rotational isomers. J Phys Chem A 117(39):9753-9760 (b) McClelland BW, Hedberg K (1987) Structure and conformations of 1,4-pentadiene in the gas phase: An electron-diffraction investigation. J Amer Chem Soc 109:7304-7309 (a) Sandwisch JW, Erickson BA, Hedberg K, Nibler JW (2017) Combined electron-diffraction and spectroscopic determination of the structure of spiropentane, C5H8. J Phys Chem A 121 (26):4923-4929 (b) Price JE, Coulterpark KA, Masiello T, Nibler JW, Weber A, Maki A, Blake TA (2011) High-resolution infrared spectra of spiropentane, C5H8 J Mol Spectrosc 269:129-136. (c) Maki A, Price JE, Harzan J, Nibler JW, Weber A, Masiello T, Blake TA (2015) Analysis of several high-resolution infrared bands of spiropentane, C5H8 J Mol Spectrosc 312:68-77. Perry A, Martin MA, Nibler JW, Maki A, Weber A, Blake TA (2012) Coriolis analysis of several high-resolution infrared bands of bicyclo[111]pentane-d0 and -d1. J Mol Spectrosc 276:22-32 Minei AJ, van Wijngaarden J, Novick SE, Pringle WC (2010) Determination of the structure of cyclopentene oxide and the argon-cyclopentene oxide van der Waals complex. J Phys Chem A 114(3):1427-1431

582

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648 649 650

651

652 653 654 655

656 657

658 659

660 661

Spada L, Tasinato N, Vazart F, Barone V, Caminati W, Puzzarini C. (2017) Noncovalent interactions and internal dynamics in pyridine-ammonia: A combined quantum-chemical and microwave spectroscopy study. Chem Eur J 23(20):4876-4883 López JC, Alonso JL, Peña I, Vaquero V (2010) Hydrogen bonding and structure of uracilwater and thymine-water complexes. Phys Chem Chem Phys 12(42):14128-14134 (a) Belova NV, Oberhammer H, Trang NH, Girichev GV (2014) Tautomeric properties and gas-phase structure of acetylacetone. J Org Chem 79 (12):5412-5419 (b) Lowrey AH, George C, D’Antonio P, Karle J (1971) Structure of acetylacetone by electron diffraction. J. Am Chem Soc 93:6399-6403 (c) Andreassen AL, Bauer SH (1972) The structures of acetylacetone, trifluoroacetylacetone and trifluoroacetone. J Mol Struct 12:381-403 (d) Iijima K, Ohnogi A, Shibata S (1987) The molecular structure of acetylacetone as studied by gas-phase electron diffraction. J Mol Struct 156:111-118 (e) Srinivasan R, Feenstra JS, Park ST, Xu S, Zewail AH (2004) Direct determination of hydrogen-bonded structures in resonant and tautomeric reactions using ultrafast electron diffraction. J Am Chem Soc 126:2266-2267 (a) See 650(a). (b) See 650(b). (c) See 650(c). (d) See 650(d). (e) See 650(e). Evangelisti L, Spada L, Li W, Blanco S, López JC, Lesarri A, Grabow JU, Caminati W (2017) A butterfly motion of formic acid and cyclobutanone in the 1:1 hydrogen bonded molecular cluster. Phys Chem Chem Phys 19(1):204-209 Pejlovas AM, Lin W, Kukolich SG (2015) Microwave spectra and structure of the cyclopropanecarboxylic acid-formic acid dimer. J Chem Phys 143(12):124311/1-124311/6 Durig JR, El Defrawy AM, Ganguly A, Gounev TK, Guirgis GA (2009) Conformational stability, r0 structural parameters, ab initio calculations, and vibrational assignment for fluorocyclopentane. J Phys Chem A 113(35):9675-9683 Defonsi Lestard ME, Tuttolomondo ME, Varetti EL, Wann DA, Robertson HE, Rankin DWH, Ben Altabef A (2010) Gas-phase structure, rotational barrier and vibrational properties of trimethysilyl trifluoroacetate CF3C(O)OSi(CH3)3: An experimental and computational study. J Mol Struct 978 (1-3):114-123 Bird RG, Vaquero-Vara V, Zaleski DP, Pate BH, Pratt DW (2012) Chirped-pulsed FTMW spectra of valeric acid, 5-aminovaleric acid, and δ-valerolactam: A study of amino acid mimics in the gas phase. J Mol Spectrosc 280:42-46 (a) Vogt N, Demaison J, Krasnoshchekov SV, Stepanov NF, Rudolph HD (2017) Determination of accurate semiexperimental equilibrium structure of proline using efficient transformations of anharmonic force fields among the series of isotopologues. Mol Phys 115(8):942-951 (b) Belyakov AV, Gureev MA, Garabadzhiu AV, Losev VA, Rykov AN (2015) Determination of the molecular structure of gaseous proline by electron diffraction, supported by microwave and quantum chemical data. Struct Chem 26 (5-6):1489-1500 Sedo G, Leopold KR (2010) Microwave spectrum of (CH3)3CCN-SO3. J Mol Spectrosc 262(2):135-138 (a) Tikhonov DS, Rykov AN, Grikina OE, Khaikin LS (2016) Gas phase equilibrium structure of histamine. Phys Chem Chem Phys 18 (8):6092-6102 (b) Vogelsanger B, Godfrey PD, Brown RD (1991) Rotational spectra of biomolecules: Histamine. J Am Chem Soc 113:7864-7869 (c) Godfrey P, Brown RD (1998) Proportions of species observed in jet spectroscopy – vibrational energy effects: Histamine tautomers and conformers. J Am Chem Soc 120:1072410732. (a) See 659(a). (b) See 659(b). (c) See 659(c). (a) Wann DA, Masters SL, Robertson HE, Green M, Kilby RJ, Russell CA, Jones C, Rankin DWH (2011) Multiple bonding versus cage formation in organophosphorus compounds: The gas-phase structures of tricyclo-P3(CBut)2Cl and P≡C-But determined by electron diffraction and computational methods. Dalton Trans 40 (20):5611-5616

7 References

662

663

664 665

666

667 668

669

670

671

672 673

674 675

583

(b) Oberhammer H, Becker G, G. Gresser G (1981) Molecular structures of phosphorus compounds. Part IX. Gas-phase structure of 2,2-dimethylpropylidynephosphitne. J Mol Struct 75:283-289 Obenchain DA, Elliott AA, Steber AL, Peebles RA, Peebles SA, Wurrey CJ, Guirgis GA (2010) Rotational spectrum of three conformers of 3,3-difluoropentane: Construction of a 480 MHz bandwidth chirped-pulse Fourier-transform microwave spectrometer. J Mol Spectrosc 261(1):35-40 Al'tova EP, Kostyanovskii RG, Shishkov IF (2014) Molecular structure of (cyanomethoxy)(dimethylamino)methane as studied by gas-phase electron diffraction and quantum-chemical calculations. Russ J Phys Chem A / Zh Fiz Khim 88 / 88 (4 / 4):667-670 / 653-656 Van V, Stahl W, Nguyen HVL (2016) The heavy atom microwave structure of 2methyltetrahydrofuran. J Mol Struct 1123:24-29 Mamleev AK, Gunderova LN, Galeev RV, Shapkin AA, Faizullin MG, Nikitina AP, Shornikov DV (2010) Structure and spectra of 1,3-dioxanes. Microwave spectrum, structural parameters, and ab initio calculations of 5-methyl-1,3-dioxane. Zh Strukt Khim 51(2):253-258; J Struct Chem (Engl Transl) 51(2):238-243 Vogt N, Demaison J, Cocinero EJ, Écija P, Lesarri A, Rudolph HD, Vogt J (2016) The equilibrium molecular structures of 2-deoxyribose and fructose by the semiexperimental mixed estimation method and coupled-cluster computations. Phys Chem Chem Phys 18(23):1555515563 Peña I, Mata S, Martín A, Cabezas C, Daly AM, Alonso JL (2013) Conformations of D-xylose: the pivotal role of the intramolecular hydrogen-bonding. Phys Chem Chem Phys 15(41):18243-18248 (a) Belyakov AV, Baskakov AA, Naraev VN, Rykov AN, Oberhammer H, Arnason I, Wallevik SO (2012) Molecular structure and conformational preferences of 1-bromo-1silacyclohexane, CH2(CH2CH2)2SiH-Br, as studies by gas-phase electron diffraction and quantum chemistry. Russ J Phys Chem A / Zh Fiz Khim 86 / 86 (10 / 10):1563-1566 / 16651668 (b) Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Arnason I, Belyakov AV, Kern T, Hassler K (2013) Conformational properties of 1-halogenated-1-silacyclohexanes, C5H10SiHX (X = Cl, Br, I): Gas electron diffraction, low-temperature NMR, temperature-dependent Raman spectroscopy, and quantum-chemical calculations. Organomet 32 (23):6996-7005 (a) Belyakov AV, Baskakov AA, Naraev VN, Rykov AN, Oberhammer H, Arnason I, Wallevik SO (2011) Molecular structure and conformational preferences of 1-chloro-1silacyclohexane, CH2(CH2CH2)2SiH-Cl, as studies by gas-phase electron diffraction and quantum chemistry. Russ J Gen Chem / Zh Obshch Khim 81/81 (11/11):2257-2261/1805-1809 (b) See 668(b). (a) Belyakov AV, Baskakov AA, Berger RJF, Mitzel NW, Oberhammer H, Arnason I, Wallevik SÒ (2012) Molecular structure and conformational preferences of gaseous 1-iodo-1silacyclohexane. J Mol Struct 1012:126-130 (b) See 668(b). Darkhalil ID, Klaassen JJ, Nagels N, Herrebout WA, van der Veken BJ, Gurusinghe RM, Tubergen MJ, Durig JR (2014) Raman and infrared, microwave spectra, conformational stability, adjusted r0 structural parameters, and vibrational assignments of cyclopentylamine. J Raman Spectrosc 45(5):392-406 Demaison J, Craig NC, Groner P, Écija P, Cocinero EJ, Lesarri A, Rudolph HD (2015) Accurate equilibrium structures for piperidine and cyclohexane. J Phys Chem A 119(9):14861493 Evangelisti C, Klapötke TM, Krumm B, Nieder A, Berger RJF, Hayes SA, Mitzel NW, Troegel D, Tacke R (2010) Sila-substitution of alkyl nitrates: Synthesis, structural characterization, and sensitivity studies of highly explosive (nitratomethyl)-, bis(nitratomethyl)-, and tris(nitratomethyl)silanes and their corresponding carbon analogues. Inorg Chem 49 (11):4865-4880 Spada L, Tasinato N, Bosi G, Vazart F, Barone V, Puzzarini C (2017) On the competition between weak O-H⋅⋅⋅F and C-H⋅⋅⋅F hydrogen bonds, in cooperation with C-H⋅⋅⋅O contacts, in the difluoromethane - tert-butyl alcohol cluster. J Mol Spectrosc 337(1):90-95 Khaikin LS, Grikina OE, Girichev GV, Kovacs A, Dyugaev KP, Astachov AM (2011) The geometry of the nitroguanyl fragment in the simplest nitroguanidine derivatives in the absence of intermolecular interactions: The gas electron diffraction data on 1,1,3,3-tetramethyl-2nitroguanidine. Russ J Phys Chem A / Zh Fiz Khim 85 / 85 (3 / 3):441-446 / 508-513

584

7 Molecules with Five Carbon Atoms

676

677 678 679 680 681

682

Shainyan BA, Kirpichenko SV, Chipanina NN, Oznobikhina LP, Kleinpeter E, Shlykov SA, Osadchiy DY (2015) Synthesis and conformational analysis of 3-methyl-3-silatetrahydropyran by GED, FTIR, NMR, and theoretical calculations: Comparative analysis of 1-hetero-3methyl-3-silacyclohexanes. J Org Chem 80 (24):12492-12500 Gou Q, Favero LB, Feng G, Evangelisti L, Pérez C, Caminati W (2017) Interactions between ketones and alcohols: Rotational spectrum and internal dynamics of the acetone-ethanol complex. Chem Eur J 23(46):11119-11125 Shlykov SA, Osadchiy DY, Chipanina NN, Oznobikhina LP, Shainyan BA (2015) Molecular structure and conformational analysis of 3-methyl-3-silathiane by gas phase electron diffraction, FTIR spectroscopy and quantum chemical calculations. J Mol Struct 1100:555-561 Knapp CE, Wann DA, Bil A, Schirlin JT, Robertson HE, McMillan PF, Rankin DWH, Carmalt CJ (2012) Dimethylalkoxygallanes: Monomeric versus dimeric gas-phase structures. Inorg Chem 51 (5):3324-3331 Evangelisti L, Pesci F, Caminati W. (2011) Adducts of alcohols with ethers: The rotational spectrum of isopropanol-dimethyl ether. J Phys Chem A 115(34) 9510-9513 Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Arnason I, Belyakov AV, Baskakov AA, Hassler K, Oberhammer H (2010) Conformational properties of 1-silyl-1-silacyclohexane, C5H10SiHSiH3: Gas electron diffraction, low-temperature NMR, temperature-dependent Raman spectroscopy, and quantum chemical calculations. J Phys Chem A 114 (5):2127-2135 Shainyan BA, Kirpichenko SV, Kleinpeter E, Shlykov SA, Osadchiy DY, Chipanina NN, Oznobikhina LP (2013) 1,3-Dimethyl-3-silapiperidine: Synthesis, molecular structure, and conformational analysis by gas-phase electron diffraction, low temperature NMR, IR and Raman spectroscopy, and quantum chemical calculations. J Org Chem 78 (8):3939-3947

Chapter 8. Molecules with Six Carbon Atoms 683 CAS RN: 392-56-3 MGD RN: 428574 Ra augmented by ab initio calculations Bonds C–F C–C

Hexafluorobenzene C6F6 D6h

F

r see [Å] a 1.3244(4) 1.3866(3)

F

F

F

F F

Reproduced with permission of AIP Publishing [a].

a

Parenthesized uncertainties in units of the last significant digit.

The rotational motion of hexafluorobenzene was recorded in a supersonic jet by femtosecond time-resolved rotational Raman coherence spectroscopy. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants accounting for rovibrational corrections calculated with the CCSD(T)/ANOn (n=0,1) harmonic and anharmonic (cubic) force constants as well as taken from Ref. [b] (calculated at the same level of theory with the wCVnZ (n=T,Q) basis sets). a. Den TS, Frey HM, Leutwyler S (2014) Accurate rotational constant and bond lengths of hexafluorobenzene by femtosecond rotational Raman coherence spectroscopy and ab initio calculations. J Chem Phys 141(19):194303/1-194303/9 [http://dx.doi.org/10.1063/1.4901284] b. Demaison J, Rudolph HD, Csaszar AG (2013) Deformation of the benzene ring upon fluorination: equilibrium structures of all fluorobenzenes. Mol Phys 111(9-11):1539-1562 684 CAS RN: 166982-32-7 MGD RN: 370962 GED augmented by QC computations Bonds P–C C–C C–F

Tris(1,1,2,2,2-pentafluoroethyl)phosphine C6F15P C3

F F

F

a

rg [Å] 1.901(3) 1.524(4) 1.338(1) b

a

rh1 [Å] 1.904(3) 1.533(3) 1.339(1) b

F

F F

F

F

P

F

F F

F

F

F F

a

Bond angles C–P–C P–C–C F–C–F

θg [deg]

Dihedral an other angles

τg [deg] a

99.9(3) 113.2(3) 108.0(1)

θh1 [deg]

a

100.1(2) 113.9(3) 108.0(1)

τh1 [deg] a

© Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_8

585

586

rock (CF2) c twist(CF2) e wag(CF2) f z…P–C–C g P–C–C–F

8 Molecules with Six Carbon Atoms

3.9(4) d 0.4(4) d 4.8(4) d 31.0(5) 182.2(10)

3.5(3) d 0.5(3) d 4.3(4) d 30.8(5) 182.2(9)

Reproduced with permission from The Royal Society of Chemistry.

a

Uncertainties given in parentheses in units of the last significant digit were not specified. Average value; differences between the C–F bond lengths were restrained to the values from the RIMP2/TZVPP computation. c Angle of rotation of the fluorine atoms around a vector normal to the P–C–C plane; a positive value means an increase in the P–C–F angles at the expense of the C–C–F angles. d Adopted from computation at the level of theory as indicated above. e Angle of rotation around the bisector of the P–C–C angle; a positive value means increase in the P–C–F(2) and C–C–F(1) angles. f Angle of rotation around a vector approximately normal to the FCF plane; positive value means an increase in the P–C–F(2) and C–C–F(2) angles. g z is the C3 axis. b

According to predictions of RIMP2/TZVPP computations, four conformers differing in the magnitude of lp–P– C–C torsional angles (lp is the phosphorus lone pair of electrons) have relative energies less than 8 kJ mol−1. The second stable conformer with C3 point-group symmetry is higher in energy by only 5 kJ mol-1 than the predominant conformer (C3 symmetry). The GED experiment was carried out at room temperature. An amount of the second lowest-energy conformer was determined to be less than 3%. Therefore, the GED data were finally fitted by the model of a single conformer. The local C3v symmetry for the CF3 groups and the overall C3 symmetry were assumed. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from B3LYP/6-311G* computation. The quality of the fit for the rh1 structure (4.7%) was indicated to be noticeably better than that for the rg structure (7.2%). Hayes SA, Berger RJF, Neumann B, Mitzel NW, Bader J, Hoge B (2010) Molecular structure of tris(pentafluoroethyl)phosphane P(C2F5)3. Dalton Trans 39 (24):5630-5636

685 CAS RN: 363-72-4 MGD RN: 781505 MW augmented by ab initio calculations

Pentafluorobenzene C6HF5 C2v

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–H C(2)–F C(3)–F C(4)–F

r0 [Å] a 1.390(7) 1.375(13) 1.395(10) 1.078 b 1.339 c 1.335 c 1.330 c

rs [Å] a 1.386(11) 1.368(4) 1.393(10)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5)

θ0 [deg] a

θs [deg] a

121.6(10) 119.5(9) 119.8(10)

121.8(11) 119.7(9) 119.3(10)

F

F

F

F F

8 Molecules with Six Carbon Atoms

C(6)–C(1)–C(2) F–C(2)–C(1) F–C(3)–C(4) H–C(1)–C(2) F–C(3)–C(2) F–C(4)–C(3)

118.0(7) 119.8(5) 118.9(8) 121.0(4) 121.7(17) 120.1(5)

587

117.7(11) 121.2(1) 120.4(1)

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Assumed at the value from MP2/6-311++G(2d,2p) calculations. c Assumed at the value taken from the literature. b

The rotational spectrum of pentafluorobenzene was recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the frequency region between 6 and 18 GHz. The partial r0 and rs structures were determined from the ground-state rotational constants of five isotopic species (main and four 13C). Bills BJ, Carroll DM, Elliott AA, Obenchain DA, Peebles SA, Peebles RA (2012) Microwave spectrum and structure of pentafluorobenzene. J Mol Struct 1023:149-153

686 CAS RN: 150693-78-0 MGD RN: 132289 MW supported by QC calculations

Distances

N(1)…H(2) N(1)…H(2)

Rcm

Angles ϕ1 d ϕ2 e

2-Propynenitrile dimer Cyanoacetylene dimer C6H2N2 C∞ v H

C

C

C

N

2

r0 [Å] a

2.2489(3) b 2.3415 c c 7.0603

θ0 [Å] a 13.0 c 8.7

c

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit (for linear model). Assuming linear model. c Using rigid precession model. Uncertainty was not given in original paper. d Angle between the a axis and the axis of the HCCCN(1) subunit. e Angle between the a axis and the axis of the other HCCCN subunit. b

The rotational spectrum of the dimer of cyanoacetylene was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 1.3 and 10.9 GHz. The structure of the complex was determined from the ground-state rotational constant using a simple linear model and assuming that the structural parameters of the monomer subunits were not changed upon complexation.

588

8 Molecules with Six Carbon Atoms

Kang L, Davis P, Dorell I, Li K, Daly A, Novick SE, Kukolich SG (2016) Rotational spectra and nitrogen nuclear quadrupole coupling for the cyanoacetylene dimer: H-C≡C-C≡N⋅⋅⋅H-C≡C-C≡N. J Mol Spectrosc 321(3):5-12

687

2,6-Difluoropyridine – carbon dioxide (1/1)

CAS RN: 2130816-57-6

MGD RN: 409916 MW supported by ab initio calculations

C6H3F2NO2

C2v

O

a

Distances Rcm b N…C c

r0 [Å] 3.9089 2.9683

Angles

θ0 [deg] a

φ

d

τe

F

N

C

O

F

30.9 10.9

Copyright 2017 with permission from Elsevier.

a

Uncertainties were not given in the original paper. Distance between the centers of mass of the monomer subunits. c Distance between N and C in the carbon dioxide subunit. d Angular oscillation of the carbon dioxide subunit about its C∞ axis. e Angular oscillation of the difluoropyridine subunit about its C2 axis. b

The rotational spectra of the binary complex of 2,6-difluoropyrdine with carbon dioxide were recorded by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 3.6 and 13 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 13C) assuming that the structural parameters of the monomer subunits were not changed upon complexation. The carbon dioxide subunit was found be located perpendicular to the ring plane of the difluoropyridine subunit. Dewberry CT, Mueller JL, Mackenzie RB, Timp BA, Marshall MD, Leung HO, Leopold KR (2017) The effect of ortho-fluorination on intermolecular interactions of pyridine: Microwave spectrum and structure of the CO22,6-difluoropyridine weakly bound complex. J Mol Struct 1146:373-379

688 CAS RN: MGD RN: 495064 MW supported by DFT calculations

Distances Rcm b N…C(1) O(1)…H(1)

3,5-Difluoropyridine – carbon dioxide (1/1) C6H3F2NO2 O

r0 [Å] a 4.623342(1) 2.8246(14) 3.091(2)

Copyright 2016 with permission from Elsevier. a

C2v

F

F

Parenthesized uncertainties in units

N

C

O

8 Molecules with Six Carbon Atoms

589

of the last significant digit. b Center-of-mass separation of the monomer subunits. The rotational spectrum of the weakly bound binary complex of 3,5-difluoropyridine with carbon dioxide was recorded by a pulsed-nozzle chirped-pulse FTMW spectrometer in the frequency region between 6 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 13C) under the assumption that the structural parameters were not changed upon complexation. The complex was found to have either planar C2v structure or effectively C2v geometry. The binding energy of the complex was predicted to be 4.3 kcal mol-1 by M06-2X/6-311++G(3df,3pd) calculation. Dewberry CT, Cornelius RD, Mackenzie RB, Smith CJ, Dvorak MA, Leopold KR (2016) Microwave spectrum and structure of the 3,5-difluoropyridine⋅⋅⋅CO2 van der Waals complex. J Mol Spectrosc 328(2) 67-72

689 CAS RN: 99-35-4 MGD RN: 363878 GED augmented by ab initio computations

Bonds C–C C–N C–H N=O

re [Å] a 1.387(1) 1.477(3) 1.07(3) 1.220(1)

Bond angles C–C(1)–C C(1)–C–C N–C–C H–C–C C–N=O O=N=O

θe [deg] a

1,3,5-Trinitrobenzene C6H3N3O6 D3h O

O N

O

O N

N

O

O

123.5(3) 116.5(3) 118.3(1) 121.7(1) 117.0(1) 126.0(2)

Reproduced with permission of SNCSC [a,b].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. The GED experiment was carried out at 453(5) K. In the GED analysis, rotation of the nitro groups was described by the large-amplitude motion model of three coupled internal rotors using three-dimensional PES from MP2_full/cc-pVTZ computations. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from scaled harmonic and anharmonic (cubic) force fields by taking into account non-linear kinematic effects. a. Khaikin LS, Kochikov IV, Grikina OE, Tikhonov DS, Baskir EG (2015) IR spectra of nitrobenzene and nitrobenzene-15N in the gas phase, ab initio analysis of vibrational spectra and reliable force fields of nitrobenzene and 1,3,5-trinitrobenzene. Investigation of equilibrium geometry and internal rotation in these simplest aromatic nitro compounds with one and three rotors by means of electron diffraction, spectroscopic, and quantum chemistry data. Struct Chem 26 (5-6):1651-1687

590

8 Molecules with Six Carbon Atoms

b. Khaikin LS, Kochikov IV, Tikhonov DS, Grikina OE (2015) Analysis of electron diffraction data for several symmetric coordinates of large-amplitude motions in the case of the 1,3,5-trinitrobenzene molecule. Russ J Phys Chem A / Zh Fiz Khimii 89 / 89 (6 / 6):1033-1040 / 1994-1001

690 CAS RN: 2508-19-2 MGD RN: 384192 GED combined with MS and augmented by QC computations

Bonds C(1)–C(2) C–C S–C(1) S–O(1) S=O(2) S=O(3) O(1)–H C–H C(2)–N(1) C–N N(1)=O(4) N–O H...O(4)

rh1 [Å] a 1.400(4) 1.387(4) b 1.811(6) 1.579(4) 1.428(4) c 1.420(4) c 0.978 d 1.078 d 1.491(5) 1.491(5) b 1.225(3) 1.216(3) b 2.07(13)

Bond angles C(1)–C(2)–C(3) C(2)–C(1)–S C(1)–S–O(1) O(2)=S–C(1) O(2)=S–O(1) O(3)=S–O(1) S–O(1)–H N(1)–C(2)–C(1) C(2)–N(1)=O(4) O(4)–N(1)=O(5)

θh1 [deg] e

Dihedral angles S–C(1)–C(2)–C(3) C(2)–C(1)–S–O(1) C(1)–S–O(1)–H N(1)–C(2)–C(1)–C(6) C(1)–C(2)–N(1)=O(4) N(3)–C(6)–C(1)–C(2) C(1)–C(6)–N(3)=O(8)

τh1 [deg] e

2,4,6-Trinitrobenzenesulfonic acid C6H3N3O9S C1 O

O N

O

O S

OH O

O N

N

O

O

122.8(2) 119.4(11) 106.9(15) 103.4(11) 110.8(12) 106.8(12) f 106.5(62) 122.1(10) 117.2(2) 125.6(6)

-162(5) -87(6) 68.7 g -172(8) 43(9) 170(5) -85(12)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Average value. c Difference to the S–O(1) bond length was assumed at the value from B3LYP/cc-pVTZ calculation. d Assumed at the value from calculation as above. e Parenthesized uncertainties in units of the last significant digit are 2.5σ values. f Difference to the O(2)=S–O(1) bond angle was assumed at the value from calculation as above.

8 Molecules with Six Carbon Atoms g

591

Assumed at the calculated value.

The GED experiment was carried out at Teffusion cell = 444(5) K. The title compound was found to exist predominantly (95(9) %) as a conformer stabilized by intramolecular hydrogen bond between the H atom of the hydroxyl group and an O atom of the nitro group. This conformer was predicted to be predominant also by B3LYP/cc-pVTZ and MP2/cc-pVDZ calculations. The amounts of two other conformers differing in the magnitudes of the C(1)–C(2)–N(1)=O(4) and C(2)–C(1)–S–O(1) torsional angles were predicted to be very small. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from QC computation. Giricheva NI, Girichev GV, Medvedeva YS, Ivanov SN, Petrov VM (2012) The influence of steric hindrance on conformation properties and molecular structure of 2,4,6-trinitrobenzenesulfonic acid: Gas electron diffraction and quantum chemical calculations. Struct Chem 23 (3):895-903

691 CAS RN: 460-00-4 MGD RN: 268537 GED augmented by QC computations

1-Bromo-4-fluorobenzene p-Bromofluorobenzene C6H4BrF C2v F

Bonds C–F C–Br C(1)–C(2) C(2)–C(3) C(3)–C(4) C–H

rh1[Å] a 1.348(4) 1.887(3) 1.397(3) b 1.399(3) b 1.386(3) b 1.089(4) c

Bond angles C(2)–C(1)–C(6) C(3)–C(4)–C(5) C–C–H C–C–Br C–C–F

θh1 [deg] a

Br

120.4(4) 122.0(4) 118.8(9) c,d 119.8(2) e 119.0(2) e

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Difference to the C–F bond length was constrained to the value from MP2/6-311+G* computation. c Constrained to the value from computation as above. d Average value. e Dependent parameter. b

The GED experiment was carried out at Tnozzle = 368 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311+G* computation. Masters SL, Mackie ID, Wann DA, Robertson HE, Rankin DWH, Parsons S (2011) Unusual asymmetry in halobenzenes, a solid-state, gas-phase and theoretical investigation. Struct Chem 22(2):279-285.

592

8 Molecules with Six Carbon Atoms

692 CAS RN: 352-33-0 MGD RN: 589658 GED augmented by QC computations

1-Chloro-4-fluorobenzene p-Chlorofluorobenzene C6H4ClF C2v F

Bonds C–Cl C–F C(1)–C(2) C(2)–C(3) C(3)–C(4) C–H

rh1[Å] a 1.749(3) 1.351(4) 1.400(3) b 1.403(3) b 1.390(3) b 1.090(4) c

Bond angles C(2)–C(1)–C(6) C(3)–C(4)–C(5) C–C–H C–C–Cl C–C–F

θh1 [deg] a

Cl

122.4(4) 122.4(4) 119.7(9) c,d 118.8(2) e 118.8(2) e

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Difference to the C–F bond length was constrained to the value from MP2/6-311+G* computation. c Constrained to the value from computation as above. d Average value. e Dependent parameter. b

The GED experiment was carried out at Tnozzle = 345 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311+G* computation. Masters SL, Mackie ID, Wann DA, Robertson HE, Rankin DWH, Parsons S (2011) Unusual asymmetry in halobenzenes, a solid-state, gas-phase and theoretical investigation. Struct Chem 22 (2):279-285

693 CAS RN: 1694-92-4 MGD RN: 387760 GED combined with MS and augmented by QC computations

Bonds C–H C(1)–C(2) C–C C–S S–Cl S=O(1) S=O(2) C(2)–N

rh1 [Å] a,b I II 1.064(15) 1,c 1.065(15) 1,c 2 1.404(3) 1.408(3) 2 c 1.397(3) 1.398(3) c 3 1.761(6) 1.783(6) 3 4 2.043(5) 2.059(5) 4 5 1.424(4) 1.423(4) 5 5 1.428(4) 1.422(4) 5 6 1.485(16) 1.486(16) 6

2-Nitrobenzenesulfonyl chloride C6H4ClNO4S C1 (I) C1 (II) O

O

S

Cl

NO2

8 Molecules with Six Carbon Atoms

N=O(4) N=O(3)

Bond angles C(2)–C(1)–C(6) C(1)–C(2)–C(3) Cl–S–C(1) C(1)–S=O(1) C(1)–S=O(2) O(1)=S–Cl O(2)=S–Cl O(1)=S=O(2) C(2)–C(1)–S C(2)–N=O(3) C(2)–N=O(4) O(3)–N=O(4) C(1)–C(2)–N Dihedral angles C(2)–C(1)–S–Cl C(1)–C(2)–N=O(3)

593

1.221(4) 7 1.223(4) 7

1.222(4) 7 1.224(4) 7

θh1 [deg] b,d

I 119.7(3) 8 121.0(3) 8 103.1(6) 9 109.5(5) 10 107.4(5) 10 108.2(6) 11 105.6(6) 11 121.6(16) e 124.9(3) 8 116.3(8) 12 116.2(8) 12 126.9(18) 13 123.4(3) 8

I 84(3) 14 141(5) 15

II 119.0(3) 8 121.2(3) 8 100.9(6) 9 109.6(5) 10 110.4(5) 10 104.8(6) 11 104.3(6) 11 124.0(16) e 122.8(3) 8 116.5(8) 12 116.7(8) 12 126.3(18) 13 123.1(3) 8

I

τh1 [deg] d

II 172(3) 16 39(7) 17

Reproduced with permission of SNCSC.

II Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/cc-pVTZ calculation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Dependent parameter. a

The GED experiment was carried out at Teffusion cell = 345(5) K. The title compound was found to exist as a mixture of two conformers, I and II, in amounts of 69(12) and 31(12) %, respectively. The conformers were found to be differing in the magnitude of the C(6)–C(1)–S–Cl torsional angle, namely, the S–Cl bond is either in near-perpendicular or near-eclipsed position with respect to the C(1)–C(6) bond. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Petrov VM, Giricheva NI, Girichev GV, Bardina AV, Petrova VN, Ivanov SN (2011) Gas electron diffraction and quantum chemical study of the structure of a 2-nitrobenzenesulfonyl chloride molecule. J Struct Chem (Engl Transl) / Zh Strukt Khim 52/52(4/4):690-698/711-720

694 CAS RN: 98-74-8 MGD RN: 152332 GED combined with MS and augmented by QC computations

4-Nitrobenzenesulfonyl chloride p-Nitrobenzenesulfonyl chloride C6H4ClNO4S Cs O

O

O N

Bonds C−H

rh1[Å] a 1.0863(6) b

O

S Cl

594

8 Molecules with Six Carbon Atoms

N=O C(1)–C(2) C(2)–C(3) C(3)−C(4) C−C S=O C(1)−S S−Cl C(4)−N

1.224(3) 1.396(3) c 1.394(3) c 1.395(3) c 1.395(3) b 1.423(3) 1.773(4) 2.048(4) 1.477(3)

Bond angles C(2)–C(1)–C(6) C(1)–C2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(1)−S−Cl C(1)−S=O Cl−S=O O=S=O O=N–C(4) O=N=O

θh1 [deg] d

Dihedral angles C(3)−C(4)−N=Oʹ C(2)−C(1)−S−Cl

τh1 [deg] d

122.8(2) e 118.5(2) e 119.0(6) e 122.3(9) e 100.2(13) 109.0(4) 106.7(2) 122.9(11) f 117.3(3) 123.6(5) f

179(10) 89(4)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Average value. c All C–C bond lengths were refined in one group. Differences to the C(1)–C(2) bond length were assumed at the values from B3LYP/6-311+G** computation. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e All C–C–C bond angles were refined in one group. Differences to the C(2)–C(1)–C(6) bond angle were assumed at the values from computation as indicated above. f Dependent parameter. The GED experiment was carried out at Teffusion cell = 391(3) K. Only one conformer was found to be present at this temperature. The barriers to internal rotations of the nitro group around the N−C(4) bond and the sulfonyl chloride group around the C(1)−S bond were estimated to be 4.7/5.3 and 4.9/6.0 kcal mol−1, respectively, at the B3LYP/6311+G**/MP2/6-31G* levels of theory. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311+G** computation. Petrov VM, Petrova VN, Girichev GV, Giricheva NI, Oberhammer H, Bardina AV, Ivanov SN, Krasnov AV (2009) Gas-phase electron diffraction and quantum chemical study of the structure of the 4-nitrobenzene sulfonyl chloride molecule. J Struct Chem (Engl Transl)/ Zh Strukt Khim 50/50(5/5):827-834/ 865-872

695 CAS RN: 433-98-7 MGD RN: 213065 GED combined with MS and augmented by

2-Nitrobenzenesulfonyl fluoride o-Nitroobenzenesulfonyl fluoride C6H4FNO4S C1 (I)

8 Molecules with Six Carbon Atoms

595

DFT computations

Bonds C–H C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C–S S–F S=O(1) S=O(2) C–N N=O(3) N=O(4) Bond angles C(2)–C(1)–C(6) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(1)–C(6)–C(5) C(1)–S–F C(1)–S=O(1) C(1)–S=O(2) O(1)=S–F O(2)=S–F O(1)=S=O(2) C(2)–C(1)–S C(2)–N=O(3) C(2)–N=O(4) O(3)=N=O(4) C(1)–C(2)–N Dihedral angles C(2)–C(1)–S–F C(1)–C(2)–N=O(3)

C1 (II) C1 (III)

I 1.101(9) 1 1.410(3) 2 1.398(3) 2 1.403(3) 2 1.402(3) 2 1.404(3) 2 1.404(3) 2 1.757(5) 3 1.527(5) 4 1.410(4) 5 1.414(4) 5 1.483(8) 6 1.212(3) 7 1.209(3) 7

I 119.5(1) 8 120.7(1) 8 119.3(6) 8 120.6(9) 8 119.8(6) 8 120.1(1) 8 98.9(14) 9 110.4(5) 10 108.1(5) 10 108.6(9) 11 106.5(9) 11 121.9(17) 124.4(1) 8 116.5(5) 12 116.9(5) 12 126.3(7) 123.1(1) 13

I 83.8(76) 125.1(41)

rh1 [Å] a,b

II 1.101(9) 1 1.412(3) 2 1.399(3) 2 1.402(3) 2 1.401(3) 2 1.405(3) 2 1.405(3) 2 1.773(5) 3 1.554(5) 4 1.409(4) 5 1.409(4) 5 1.481(8) 6 1.212(3) 7 1.211(3) 7

θh1 [deg] b,c

II 118.9(1) 8 121.1(1) 8 119.4(6) 8 120.2(9) 8 120.1(6) 8 120.2(1) 8 94.6(14) 9 110.6(5) 10 111.5(5) 10 105.8(9) 11 105.8(9) 11 124.1(17) 122.7(1) 8 116.6(5) 12 117.3(5) 12 125.8(7) 122.2(1) 13

τh1 [deg] c

II 147.2(86) 24.6(168)

O

III 1.101(9) 1 1.412(3) 2 1.400(3) 2 1.402(3) 2 1.401(3) 2 1.405(3) 2 1.404(3) 2 1.767(5) 3 1.533(5) 4 1.408(4) 5 1.415(4) 5 1.484(8) 6 1.209(8) 7 1.214(10) 7

O

S F O

N O

I

III 119.1(1) 8 120.6(1) 8 119.7(6) 8 120.4(9) 8 119.8(6) 8 120.4(1) 8 97.0(14) 9 113.0(5) 10 107.1(5) 10 108.9(9) 11 106.9(9) 11 121.0(17) 127.0(1) 8 117.3(5) 12 116.4(5) 12 125.8(7) 123.5(1) 13

II

III 45.1 d 36.3 d

Copyright 2009 with permission from Elsevier.

III a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences to parameter of the conformer I were assumed at the values from B3LYP/6-311+G** computation. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Assumed at the value from computation as indicated above.

596

8 Molecules with Six Carbon Atoms

The GED experiment was carried out at Tnozzle = 383(5) K. Three conformers, I, II and III, characterized by different positions of the S–F bond with respect to the benzene ring, i.e. differing in the magnitude of the C(2)–C(1)–S–F torsion angle, were considered in the GED model. The ratio of the conformers was determined to be I : II : III = 74(6) : 26(10) : 0(6) (in %). According to predictions of B3LYP/6-311+G** and MP2/6-31G** computations, conformers II and III are higher in energy in comparison to conformer I by about 0.7 and 1.5 kcal mol–1, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from B3LYP/6-311+G** computation. Petrov VM, Girichev GV, Oberhammer H, Giricheva NI, Bardina AV, Petrova VN, Ivanov SN (2010) Molecular structure and conformations of 2-nitrobenzenesulfonyl fluoride: Gas-phase electron diffraction and quantum chemical calculations study. J Mol Struct 978 (1-3):97-103

696 CAS RN: 367-11-3 MGD RN: 957078 MW augmented by QC calculations

1,2-Difluorobenzene o-Difluorobenzene C6H4F2 C2v F

Bonds C(1)–F C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(3)–H C(4)–H

r see [Å] a 1.3368(8) 1.3852(6) 1.3830(8) 1.3918(4) 1.3892(7) 1.0816(4) b 1.0796(2)

Bond angles C(1)–C(2)–F C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(3)–H C(3)–C(4)–H

θ see [deg] a

F

119.122(29) 120.590(21) 119.130(23) 120.279(13) 118.729(56) b 119.46(28)

Reprinted by permission of Taylor & Francis Ltd. Final version received 2 April 2013 [a].

a

Parenthesized uncertainties in units of the last significant digit. Constrained to the value calculated at the CCSD(T)_ae/cc-pCVTZ level of theory and extrapolated to the ccpwCVQZ basis set (at MP2 level). b

The semiexperimental equilibrium structure r see was determined from the previously published experimental ground-state rotational constants taking into account rovibrational corrections calculated with the B3LYP/631G* quadratic and cubic force fields. a. Demaison J, Rudolph HD, Császár AG (2013) Deformation of the benzene ring upon fluorination: equilibrium structures of all fluorobenzenes. Mol Phys 111(9-11):1539-1562

8 Molecules with Six Carbon Atoms

597

GED supported by MW and augmented by MM computations

Bonds C–C C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C–F C–H C(3)–H C(4)–H

rh0 [Å] a 1.3934(10) b 1.389(3) c 1.380(3) c 1.393(3) c 1.411(3) c 1.344(3) 1.081(2) b 1.080(3) d 1.082(3) d

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5)

θh0 [deg] a

C2v

120.7(1) 119.4(2) e 119.9(1) e

Copyright 2010 with permission from Elsevier [b].

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value. c Derived due to refined differences in the C–C bond lengths. d Derived due to refined differences in the C–H bond lengths. e Dependent parameter. b

The GED experiments were carried out at Tnozzle = 293 K. Vibrational corrections to the experimental internuclear distances, ∆rh0 = ra − rh0, and rotational constants, ∆Bh0 = Bh0 − B0, were calculated using harmonic force field from MM3 computations. b. Brown EM, Wann DA, Rankin DWH (2010) Anisotropy of indirect couplings and accurate molecular structures of 1,2- and 1,3-difluorobenzenes by combined analysis of gas electron diffraction, rotational spectroscopy and liquid crystal NMR data. J Mol Struct 984 (1-3):102-110

697 CAS RN: 372-18-9 MGD RN: 387089 MW augmented by DFT calculations Bonds C(1)–C(2) C(3)–C(4) C(4)–C(5) C(2)–H C(4)–H C(5)–H C(1)–F

r see [Å] a 1.38473(68) 1.3819(12) 1.39070(28) 1.07891(28) 1.07851(18) 1.0795(49) 1.34164(78)

Bond angles

θ see [deg] a

1,3-Difluorobenzene m-Difluorobenzene C6H4F2 C2v F

F

598

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(3)–C(4)–H C(5)–C(4)–H C(2)–C(1)–F C(6)–C(1)–F

8 Molecules with Six Carbon Atoms

116.853(72) 122.866(36) 118.164(14) 121.087(16) 119.810(24) 122.025(21) 118.07(10) 119.068(71)

Reprinted by permission of Taylor & Francis Ltd. Final version received 2 April 2013 [a].

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see was determined from the previously published experimental ground-state rotational constants taking into account rovibrational corrections calculated with the B3LYP/6311+G(3df,2pd) harmonic and anharmonic (cubic) force fields and applying the Huber weighting scheme. a. Demaison J, Rudolph HD, Császár AG (2013) Deformation of the benzene ring upon fluorination: equilibrium structures of all fluorobenzenes. Mol Phys 111(9-11):1539-1562 GED supported by MW and augmented by MM computations

Bonds C–C C(1)–C(2) C(3)–C(4) C(4)–C(5) C–F C–H C(2)–H C(4)–H C(5)–H

rh0 [Å] a 1.3913(13) b 1.395(3) c 1.388(3) c 1.392(3) c 1.334(4) 1.080(3) b 1.083(4) d 1.081(4) d 1.078(5) d

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(3)–F C(3)–C(4)–H

θh0 [deg] a

C2v

117.8(3) 121.7(3) 119.1(3) e 118.3(2) 119.1(2)

Copyright 2010 with permission from Elsevier [b].

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Average value. c Derived due to refined differences in the C–C bond lengths. d Derived due to refined differences in the C–H bond lengths. e Dependent parameter. b

The GED experiments were carried out at Tnozzle = 293 K. Vibrational corrections to the experimental internuclear distances, ∆rh0 = ra − rh0, and ground-state rotational constants, ∆Bh0 = Bh0 − B0, were calculated using harmonic force field from MM3 computations.

8 Molecules with Six Carbon Atoms

599

b. Brown EM, Wann DA, Rankin DWH (2010) Anisotropy of indirect couplings and accurate molecular structures of 1,2- and 1,3-difluorobenzenes by combined analysis of gas electron diffraction, rotational spectroscopy and liquid crystal NMR data. J Mol Struct 984 (1-3):102-110

698 CAS RN: 540-36-3 MGD RN: 600458 Ra augmented by ab initio calculations

1,4-Difluorobenzene p-Difluorobenzene C6H4F2 D2h

F

Bonds C(1)–C(2) C(2)–C(3) C–F C–H

r see [Å] a 1.3849(4) 1.3917(4) 1.3422(3) 1.0791(5)

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–H

θ see [deg] a

F

122.11(1) 118.94(1)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotationally resolved femtosecond Raman coherence spectrum of 1,4-difluorobenzene was recorded in a supersonic jet. The semiexperimental equilibrium structure r see was determined from the ground-state rotational constants by taken into account rovibrational correction calculated with the CCSD(T)/cc-pwCVDZ harmonic and anharmonic (cubic) force fields. Den T, Frey HM, Felker PM, Leutwyler S (2015) Rotational constants and structure of para-difluorobenzene determined by femtosecond Raman coherence spectroscopy: A new transient type. J Chem Phys 143(14):144306/1-144306/12 [http://dx.doi.org/10.1063/1.4932602]

699 CAS RN: 367-27-1 MGD RN: 148331 MW augmented by ab initio calculations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–O

2,4-Difluorophenol C6H4F2O Cs

OH

r0 [Å] a 1.393(3) 1.378(4) 1.386(4) 1.388(7) 1.400(14) 1.387(10) 1.365 b

rs [Å] a 1.381(3) 1.366(2) 1.386(2) 1.393(1) 1.368(1) 1.414(2) 1.367(1)

F

F

600

8 Molecules with Six Carbon Atoms

O–H C(2)–F C(4)–F C(3)–H C(5)–H C(6)–H

0.963 b 1.358 b 1.352 b 1.079 b 1.079 b 1.080 b

0.923(7)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(1)–O–H C(2)–C(1)–O F–C(2)–C(1) C(2)–C(3)–H C(3)–C(4)–F C(4)–C(5)–H C(5)–C(6)–H C(6)–C(1)–O

θ0 [deg] a

θs [deg] a

123.0(5) 117.0(5) 122.4(9) 118.7(13) 120.3(13) 118.4(5) 108.2 b 121.9 b 117.7(5) 121.1 b 118.4 b 119.8 b 120.8 b 119.6(13)

123.81(38) 116.95(24) 122.12(24) 119.08(13) 120.57(10) 117.46(30) 110.03(50) 122.54(29)

120.00(16)

Copyright 2017 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed at the value from MP2/6-311++G(d,p) calculation.

The rotational spectrum of the title molecule was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 5 and 25 GHz. The partial r0 and rs structures were determined from the ground-state rotational constants of nine isotopic species (main, six 13C, D and 18O). The structural analysis showed that the hydrogen atom of hydroxyl group is located in the ring plane forming an intramolecular hydrogen bond with the nearest F atom. Nair KPR, Dewald D, Wachsmuth D, Grabow JU (2017) Supersonic jet cooled rotational spectrum of 2,4difluorophenol. J Mol Spectrosc 335(5):23-26

700 CAS RN: 2396-01-2 MGD RN: 149376 MW augmented by ab initio calculations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(2)–H C(3)–H C(4)–H

Phenyl C 6H 5 C2v

r0 [Å] a 1.3828(60) 1.4043(73) 1.3933(60) 1.0768(50) 1.0845(52) 1.0823(62)

r see [Å] a 1.3730(28) 1.3981(32) 1.3927(30) 1.0806(21) 1.0815(22) 1.0818(26)

8 Molecules with Six Carbon Atoms

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) H–C(2)–C(1) H–C(3)–C(2)

θ0 [deg] a

126.01(69) 116.10(53) 122.10(70) 119.24(72)

601

θ see [deg] a

125.80(30) 116.60(23) 122.36(30) 119.82(32)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The phenyl radical was produced by a DC glow discharge. The rotational spectrum was recorded by a free-space millimeter-wave direct absorption spectrometer. The r0 structure for the 2A1 electronic ground state was determined from the ground-state rotational constants of nine isotopic species (main, four 13C, three D1 and D5). The semiexperimental equilibrium structure was obtained by taking into account rovibrational corrections calculated from the CCSD(T)/ANO0 harmonic and anharmonic (cubic) force fields. Martinez O, Crabtree KN, Gottlieb CA, Stanton JF, McCarthy MC (2015) An accurate molecular structure of phenyl, the simplest aryl radical. Angew Chem 127(6).1828-1831; Angew Chem Int Ed 54(6):1808-1811.

701 CAS RN: 462-06-6 MGD RN: 628720 MW augmented by DFT calculations

Fluorobenzene C6H5F C2v F

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(2)–H C(3)–H C(4)–H C(1)–F

r see [Å] a 1.3834(5) 1.3933(13) 1.3910(4) 1.0780(6) 1.0799(3) 1.0801(3) 1.3435(10)

Bond angles C(2)–C(1)–C(6) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(1)–C(2)–H C(4)–C(3)–H

θ see [deg] a 122.67(7) 118.27(5) 120.43(3) 119.93(3) 119.81(7) 120.20(4)

Reprinted by permission of Taylor & Francis Ltd. Final version received 2 April 2013

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see was determined from the previously published experimental ground-state rotational constants of nine isotopic species (main, four 13C, three D and D3) taking into account rovibrational corrections calculated with the B3LYP/6-31G* harmonic and anharmonic (cubic) force constants.

602

8 Molecules with Six Carbon Atoms

Demaison J, Rudolph HD, Császár AG (2013) Deformation of the benzene ring upon fluorination: equilibrium structures of all fluorobenzenes. Mol Phys 111(9-11):1539-1562

702 CAS RN: 367-12-4 MGD RN: 898640 MW augmented by ab initio calculations

2-Fluorophenol o-Fluorophenol C6H5FO Cs OH

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1)

r0 [Å] a 1.392(2) 1.380(3) 1.396(3) 1.402(4) 1.396(3) 1.391(3)

rs [Å] a 1.379(3) 1.374(4) 1.401(2) 1.392(3) 1.399(2) 1.385(4)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2)

θ0 [deg] a

θs [deg] a

122.9(3) 118.4(3) 119.7(4) 120.7(4) 119.7(3) 118.6(3)

F

123.3(3) 118.0(2) 119.8(1) 120.7(1) 119.4(1) 118.9(3)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title molecule was ivestigated in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 26 GHz. Only one conformer with the synperiplanar H–O– C(1)–C(2) fragment was observed. The r0 structure of the ring skeleton was determined from the ground-state rotational constants of seven isotopic species (main and six 13C); the remaining structural parameters were assumed at the MP2/6-311++G(2d,2p) values. The partial rs structure was also determined. According to results of the NBO analysis, the OH…F intramolecular interaction stabilizes this conformer by 0.73 kcal mol-1. Bell A, Singer J, Desmond D, Mahassneh O, van Wijngaarden J (2017) Rotational spectra and conformer geometries of 2-fluorophenol and 3-fluorophenol. J Mol Spectrosc 331(1):53-59

703 CAS RN: 372-20-3 MGD RN: 335241 MW augmented by ab initio calculations

Bonds C(1)–C(2)

3-Fluorophenol m-Fluorophenol C6H5FO Cs

r0 [Å] a 1.395(5)

rs [Å] a 1.416(11)

8 Molecules with Six Carbon Atoms

C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1)

1.383(5) 1.385(2) 1.398(3) 1.394(3) 1.398(2)

603

1.367(11) 1.376(6) 1.341(93) 1.448(93) 1.384(6)

OH

F

θ0 [deg] a

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2)

117.4(5) 123.9(5) 117.3(3) 121.0(4) 119.3(3) 121.0(5)

θs [deg] a

116.8(3) 124.6(4) 118.7(23) 120.8(2) 118.1(21) 120.9(3)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title molecule was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 26 GHz. Two planar conformers, anti and syn, with the antiperiplanar and synperiplanar H–O–C(1)–C(2) fragments, respectively, were observed. For the lowest-energy anti conformer the r0 structure of the ring skeleton was obtained from the ground-state rotational constants of seven isotopic species (main and six 13C); the remaining structural parameters were assumed at the MP2/6-311++G(2d,2p) values. The rs structure was also determined for the ring skeleton. Bell A, Singer J, Desmond D, Mahassneh O, van Wijngaarden J (2017) Rotational spectra and conformer geometries of 2-fluorophenol and 3-fluorophenol. J Mol Spectrosc 331(1):53-59

704 CAS RN: 2557-78-0 MGD RN: 541687 MW supported by ab initio calculations

Bonds

C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–S

Bond angles

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(1)–C(2)–F C(2)–C(1)–S

2-Fluorobenzenethiol 2-Fluorothiophenol C6H5FS

Cs (syn) SH

r0 [Å] a

1.383(6) 1.387(2) 1.392(5) 1.402(6) 1.395(4) 1.398(7) 1.772(6)

θ0 [deg] a 122.6(7) 118.8(5) 119.8(6) 120.2(6) 120.3(8) 118.3(6) 118.9(7) 123.1(6)

Copyright 2017 with permission from Elsevier.

F

604 a

8 Molecules with Six Carbon Atoms

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the frequency region between 4 and 26 GHz. The observed transitions were assigned to two planar conformers with the S–H bond directed either towards (syn) or away (anti) from the F atom. The partial r0 structure was determined only for the syn conformer from the ground-state rotational constants of eight isotopic species (parent, six 13C and 34S). Sun WH, van Wijngaarden J (2017) Structural elucidation of 2-fluorothiophenol from Fourier transform microwave spectra and ab initio calculations. J Mol Struct 1144:496-501

705 CAS RN: MGD RN: 208608 MW supported by ab initio calculations

Distances N…C Rcm b

r0 [Å] a 3.372(1) 4.765

Pyridine – tetrafluoromethane (1/1) C6H5F4N C2v F

N

F

F

F

Reprinted with permission. Copyright 2009 American Chemical Society.

a b

Parenthesized uncertainty in units of the last significant digit. Distance between centers of mass of the monomer subunits.

The rotational spectrum of the binary complex of pyridine with tetrafluoromethane was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 15N) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The tetrafluoromethane subunit is located as a cap above the N atom; both subunits are freely rotating with respect to each other. Maris A, Favero LB, Velino B, Caminati W (2013) Pyridine-CF4: a molecule with a rotating cap. J Phys Chem A 117(44):11289-11292

706 CAS RN: 591-50-4 MGD RN: 949411

Iodobenzene C6H5I

8 Molecules with Six Carbon Atoms

605

MW augmented by ab initio calculations

C2v

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–I

r0 [Å] a 1.412(15) 1.400(10) 1.39(4) 2.063(21)

Bond angles C(1)–C(2)–C(3) C(2)–C(1)–C(6) C(2)–C(3)–C(4) C(2)–C(1)–I

θ0 [deg] a

I

119.9(10) 119.0(15) 120.5(12) 121.1(13)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded by a chirped-pulse FTMW spectrometer in the spectral region between 2 and 8 GHz. The r0 structure of the heavy-atom skeleton was determined from the ground-state rotational constants of five isotopic species (main and four 13C); the structural parameters involving hydrogen atoms were assumed at the values from MP2/6-311++G(d,p) calculations. Neill JL, Shipman ST, Alvarez-Valtierra L, Lesarri A, Kisiel Z, Pate BH (2011) Rotational spectroscopy of iodobenzene and iodobenzene-neon with a direct digital 2-8 GHz chirped-pulse Fourier transform microwave spectrometer. J Mol Spectrosc 269(1):21-29

707 CAS RN: MGD RN: 216657 MW supported by ab initio calculations

Distance Rcm b

r0 [Å] a 3.805

Angles

θ0 [deg] a

c

θ ϕd

Iodobenzene – neon (1/1) I

C6H5INe Cs Ne

27.93 15.27

Copyright 2011 with permission from Elsevier.

a

Uncertainties were not given in the original paper. Distance between Ne and the center-of-mass of iodobenzene. c Angle between Rcm and the c principal axis of iodobenzene. d Angle between the projection of Rcm onto the ab plane of iodobenzene and the a principal axis of iodobenzene. b

The rotational spectrum of the binary van der Waals complex of iodobenzene with neon was recorded by a chirped-pulse FTMW spectrometer in the spectral region between 2 and 8 GHz.

606

8 Molecules with Six Carbon Atoms

The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 20Ne) assuming the structural parameters of the iodobenzene subunit were not changed upon complexation. Neill JL, Shipman ST, Alvarez-Valtierra L, Lesarri A, Kisiel Z, Pate BH (2011) Rotational spectroscopy of iodobenzene and iodobenzene-neon with a direct digital 2-8 GHz chirped-pulse Fourier transform microwave spectrometer. J Mol Spectrosc 269(1):21-29

708 CAS RN: 98-95-3 MGD RN: 390162 GED supplemented by MW and augmented by ab initio computations

Nitrobenzene C6H5NO2 C2v O N

a

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C–N C(2)–H C(3)–H C(4)–H N=O

re [Å] 1.387(1) 1.390(1) 1.393(1) 1.482(4) 1.077(5) 1.079(5) 1.079(5) 1.219(2)

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) N–C–C H–C(2)–C(1) H–C(2)–C(3) H–C(3)–C(2) H–C(3)–C(4) H–C(4)–C(3) C–N=O O=N=O

θe [deg] a

O

123.5(4) 117.6(5) 120.5(2) 120.1(2) 118.2(4) 119.6(1) 122.8(3) 119.5(1) 120.0(1) 119.9(1) 117.5(6) 125.0(6)

Reproduced with permission of SNCSC [a]. a

Parenthesized uncertainties in units of the last significant digit are 3σ values.

The GED experiment was carried out at 353(5) K. In the GED analysis, the internal rotation of the nitro group was described by the large-amplitude motion model based on the one-dimensional PEF from MP2_full/aug-cc-pVTZ computation. The barrier to rotation, estimated to be 4.5 kcal mol-1 at the MP2_full/cc-pVTZ level of theory, is in agreement with that determined in Ref. [b] by GED (4.6(2) kcal mol-1). Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated from scaled quadratic and cubic force constants taking into account non-linear kinematic effects. a. Khaikin LS, Kochikov IV, Grikina OE, Tikhonov DS, Baskir EG (2015) IR spectra of nitrobenzene and nitrobenzene-15N in the gas phase, ab initio analysis of vibrational spectra and reliable force fields of nitrobenzene and 1,3,5-trinitrobenzene. Investigation of equilibrium geometry and internal rotation in these simplest aromatic nitro compounds with one and three rotors by means of electron diffraction, spectroscopic, and quantum chemistry data. Struct Chem 26 (5-6):1651-1687

8 Molecules with Six Carbon Atoms

607

b. Dorofeeva OV, Vishnevskiy YV, Vogt N, Vogt J, Khristenko LV, Krasnoshchekov SV, Shishkov IF, Hargittai I, Vilkov LV (2007) Molecular structure and conformation of nitrobenzene reinvestigated by combined analysis of gas-phase electron diffraction, rotational constants, and theoretical calculations. Struct Chem 18:739753

709 CAS RN: 98-98-6 MGD RN: 427737 MW supported by ab initio calculations

2-Pyridinecarboxylic acid Picolinic acid C6H5NO2 Cs O

Bonds C(1)–N(2) C(1)–C(6) C(5)–C(6) C(4)–C(5) C(7)=O(8)

rs [Å] a 1.35(39) 1.41(16) 1.37(17) 1.40(29) 1.23(14)

Bond angles C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–N(2)

θs [deg] a

N

OH

119.32(47) 118.88(22) 122.15(57)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of picolinic acid were recorded in a supersonic jet by chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 6.5 and 18 GHz. The sample was vaporized by laser ablation. Two planar conformers were observed. For the most stable conformer the partial rs structure of the heavy atom skeleton was determined from the ground-state rotational constants of eight isotopic species (main, five 13C, 15N and 18O). The values of the inertial defect and the quadrupole coupling constants obtained for this conformer give evidence the formation of an intramolecular hydrogen bond. Peña I, Varela M, Franco VG, López JC, Cabezas C, Alonso JL (2014) Picolinic and isonicotinic acids: A Fourier transform microwave spectroscopy study. J Phys Chem A 118(48):11373-11379

710 CAS RN: 147767-79-1 MGD RN: 211569 MW

Distances C(2)…N Rcm b O…H(1)

r0 [Å] a 2.7977(64) 4.19269 3.090(6)

Angles

θ0 [deg]

ϕc

9.0

Pyridine – carbon dioxide (1/1) C6H5NO2 C2v O

N

C

O

608

φd

8 Molecules with Six Carbon Atoms

2.4

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Center-of-mass separation between the monomer subunits. c Angular oscillation of pyridine subunit about its C2 axis. d Angular oscillation of carbon dioxide subunit about its C∞ axis. b

The rotational spectrum of the binary complex of pyridine with carbon dioxide was recorded in a supersonic jet by a pulsed-nozzle FTMW spectrometer. The partial r0 structure was determined from the ground-state rotational constants of the five isotopic species (parent and four 13C) assuming that the structural parameters of the monomer subunits were not changed upon complexation. The data indicated a planar structure in which the pyridine nitrogen approaches the carbon atom of the CO2 unit along the C2 axis of pyridine perpendicular to the CO2 axis. No evidence of internal rotation was observed. Doran JL, Hon B, Leopold KR (2012) Rotational spectrum and structure of the pyridine-CO2 van der Waals complex. J Mol Struct 1019 191-195

711 CAS RN: 80-82-0 MGD RN: 213606 GED combined with MS and augmented by DFT computations

2-Nitrobenzenesulfonic acid C6H5NO5S C1 O

O

S OH

a,b

Bonds C–H C(1)–C(2) C–C C–S S–O(3) S=O O(3)–H(1) C(2)–N N=O(4) N=O(5)

rh1[Å] 1.071(11) 1.409(4) 1.401(4) c 1.767(6) 1.560(6) 1.412(4) 0.985(25) 1.461(8) 1.225(5) 1 1.210(5) 1

Bond angles C(2)–C(1)–C(6) C(1)–C(2)–C(3) C(1)–S–O(3) O(1)=S–O(3) O(2)=S–O(3) O(1)=S=O(2) S–O(3)–H(1) C(2)–C(1)–S C(2)–N=O(4) C(2)–N=O(5) O(4)=N=O(5) C(1)–C(2)–N

θh1 [deg] b,d 118.8(3) 2 121.2(3) 2 103.7(23) 109.8(27) 3 104.8(27) 3 122.1(50) e 106(10) 125.0(3) 2 118.4(5) 4 117.6(5) 4 124.0(10) 122.9(4)

NO2

8 Molecules with Six Carbon Atoms

Dihedral angles C(2)–C(1)–S–O(3) C(1)–S–O(3)–H(1) C(1)–C(2)–N=O(4)

609

τh1 [deg] d -71.5(63) 66.9 f 40.2(42)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were adopted from B3LYP/6-311++G** calculation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Dependent parameter. f Refined, then fixed to the value from computation as indicated above. The GED experiment was carried out at Teffusion cell = 394(5) K. The title compound was found to exist as a single conformer stabilized due to formation of the H(1)…O(4) hydrogen bond. The DFT calculations confirmed that the other conformers, being noticeably higher in energy than the lowest energy conformer (by more than 5.5 kcal mol−1 (B3LYP/cc-pVTZ)), should be absent in the gas phase at the temperature of the experiment. In the GED analysis, the benzene ring was assumed to be planar and the S=O(1) bond was found to be eclipsing the O(3)−H bond. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated from the B3LYP/6-311++G** harmonic force field. Petrov VM, Giricheva NI, Girichev GV, Petrova VN, Ivanov SN, Bardina AV (2011) Gas electron diffraction and quantum chemical studies of the molecular structure of 2-nitrobenzenesulfonic acid. J Struct Chem (Engl Transl)/Zh Strukt Khim 52/52(1/1):60-68/65-73

712 CAS RN: 98-47-5 MGD RN: 344380 GED combined with MS and augmented by QC computations

Bonds C–H C(1)–C(2) C–C C–S S–O(1) S=O O–H C–N N=O(4)

rh1 [Å] a 1.090(7) b 1.394(4) 1.395(4) b,c 1.784(5) 1.620(4) 1.438(4) b,d 0.968 e 1.477(4) d 1.223(4)

Bond angles C(1)–C(2)–C(3) C(2)–C(1)–C(6) C(2)–C(3)–C(4) S–C(1)–C(2) O(1)–S–C(1) O(2)=S–C(1) O(2)=S–O(1)

θh1 [deg] a 117.5(3) 121.6(3) f 122.4(3) f 118.9(6) 101.6(24) 109.3(8) 106.3(11)

3-Nitrobenzenesulfonic acid C6H5NO5S C1 (I) C1 (II)

610

8 Molecules with Six Carbon Atoms

H–O(1)–S C–N=O(4)

107.9 e 117.7(4)

Dihedral angles S–C(1)–C(2)–C(3) O(1)–S–C(1)–C(2) H–O(1)–S=O(2)

τh1 [deg] a 175(6) -88(5) -11.0 e

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Average value. c Difference to C(1)–C(2) was assumed at the value from B3LYP/cc-pVTZ computation. d Difference to S–O(1) was assumed at the value from computation as indicated above. e Adopted from calculations as indicated above. f Difference to C(1)–C(2)–C(3) was assumed at the value from computation as indicated above. Two conformers, I and II, with O–H group approximately eclipsing the S=O(2) and S=O(3) bonds, respectively, were predicted by QC computations (MP2 and B3LYP in conjunction with cc-pVTZ basis set). In the GED analysis (Teffusion cell = 431(5) K), the ratio of conformers was found to be I : II = 55:45 (in %). Differences between structural parameters of the conformers were assumed at the values from B3LYP computations. The nitro group was assumed to be coplanar with the benzene ring. The structural parameters were presented for conformer I. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP computation (with basis set as indicated above). Giricheva NI, Girichev GV, Fedorov MS, Ivanov SN (2013) Substituent effect on geometric and electronic structure of benzenesulfonic acid: Gas-phase electron diffraction and quantum chemical studies of 4CH3C6H4SO3H and 3-NO2C6H4SO3H molecules. Struct Chem 24 (3):807-818

713 CAS RN: 71-43-2 MGD RN: 595991 GED

Bonds C–C C–H

ra [Å] a 1.398(2) 1.091(5)

Copyright 2010 with permission from Elsevier .

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.001r. Determination of structural parameters was carried out in order to test an improved scanning and initial data processing technique for photographic registration. The temperature of the GED experiment was not stated, most probably room temperature.

Benzene C 6H 6 D6h

8 Molecules with Six Carbon Atoms

611

Zakharov AV, Zhabanov YA (2010) An improved data reduction procedure for processing electron diffraction images and its application to structural study of carbon tetrachloride. J Mol Struct 978 (1-3):61-66

714 CAS RN: 3227-90-5 MGD RN: 693879 GED combined with IR and augmented by DFT computations Bonds C–H C=C C–C

r 0α [Å] a 1.072(17) 1.330(4) 1.437(4)

Bond angle H–C–H

θ 0α [Å] a

Tris(methylene)cyclopropane [3]-Radialene C 6H 6 D3h

rg [Å] a 1.092(17) 1.335(4) 1.440(4)

117.5(20)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2σ and a systematic error. The GED experiment was carried out at Tnozzle = 298 K. Vibrational corrections to the experimental internuclear distances, ∆r 0α = ra − r 0α , were calculated using harmonic force constants from B3LYP/cc-pVTZ computations as well as taking into account anharmonic contributions estimated with Morse constant (taken to be 2 Å-1). High-resolution FTIR spectra were recorded in the frequency region between 600 cm-1 and 1000 cm-1. Rovibrational corrections to experimental ground-state rotational constants, ∆Bz = Bz – B0, were calculated using harmonic force constants from computation at the level of theory as indicated above. Wright C, Holmes J, Nibler JW, Hedberg K, White JD, Hedberg L, Weber A, Blake TA (2013) High-resolution infrared and electron-diffraction studies of trimethylenecyclopropane ( 3 -radialene). J Phys Chem A 117 (19):4035-4043

715 CAS RN: 31014-03-6 MGD RN: 117655 IR

Ethyne trimer Acetylene trimer C 6H 6 C3h H

Distance Rcm b

r0 [Å] 4.351

a

Reprinted by permission of Taylor & Francis Ltd. Final version received 15 May 2012.

a b

Uncertainty was not given in the original paper. Distance between the centers of mass of two ethyne subunits.

C

C

H

3

612

8 Molecules with Six Carbon Atoms

The rotationally resolved IR spectra of the deuterated ethyne trimer were recorded in a supersonic jet by a tunable diode laser spectrometer in the region of ν3 fundamental band of C2D2 at about 2440 cm-1. The Rcm distance was determined from the ground-state rotational constants of deuterated species assuming that the structural parameters of the ethyne subunits were not changed upon complexation. Norooz Oliaee J, Moazzen-Ahmadi N, McKellar ARW (2012) New spectroscopic results on acetylene dimers and trimers. Mol Phys 110(21-22):2797-2805

716 CAS RN: 220859-57-4 MGD RN: 147322 MW supported by ab initio calculations

1,4-Difluorobenzene – water (1/1) C6H6F2O Cs (see comment) F

O

Distance H(1)…O(2)

r0 [Å] a 2.489(9)

Angles C–H(1)…O(2)

θ0 [deg] a

βb

H

H

F

134.53(23) 130(12)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. b Angle between H(1)…O(2) and the C2 axis of the water subunit. The rotational spectra of the title complex were recorded by a pulsed-jet FTMW spectrometer in the spectral region between 3 and 15 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 17 O, 18O and D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The determined structure corresponds to a planar (or nearly planar) configuration of the complex. The observed tunneling splittings of the rotational lines indicated the hindered internal rotation of the water subunit about its C2 axis. The barrier height was determined to be 346 cm-1. Brendel K, Mäder H, Xu Y, Jäger W (2011) The rotational spectra of the fluorobenzene⋅⋅⋅water and pdifluorobenzene⋅⋅⋅water dimers: Structure and internal dynamics. J Mol Spectrosc 268(1-2):47-52

717 CAS RN: 1201170-60-6 MGD RN: 211244 MW supported by ab initio calculations

Distances N(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5)

Pyridine – trifluoromethane (1/1) C6H6F3N Cs F

rs [Å]a 1.344(4) 1.392(3) 1.411(5) 1.374(7)

N

F

F

8 Molecules with Six Carbon Atoms

C(5)–C(6) C(6)–N(1) C(1)...N(1) N(1)...H(1) F(1)...H(2)

1.395(2) 1.344(2) 3.287(1) b 2.317(1) c 2.700(7) c

Bond angles N(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–N(1) C(6)–N(1)–C(2) C(1)...N(1)–C(2) C(2)–N(1)...C(1) N(1)...C(1)–H(1) C(1)–H(1)...N(1) C(2)–H(2)...F(1)

θs [deg]a

613

123.7(4) 117.8(5) 118.8(7) 119.0(7) 123.4(3) 117.2(4) 99(1) 101.1(2) b 22.2(1) b 147.6(2) c 129.5(2) c

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. r0 value. c Dependent parameter. b

The rotational spectra were recorded by a pulsed supersonic-jet FTMW spectrometer in the frequency range between 6 and 18.5 GHz. The mixed rs/r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, six 13C and 15N). This structure supplies the rotationally determined weak hydrogen bond H…N as well as the weak H(2)…F(1) interaction. The existence of the observed conformer was also predicted by MP2/6-311++G** calculations. Favero LB, Giuliano BM, Maris A, Melandri S, Ottaviani P, Velino B, Caminati W (2010) Features of the C⋅⋅⋅N weak hydrogen bond and internal dynamics in pyridine-CHF3. Chem Eur J 16(6):1761-1764 718 CAS RN: 361-82-0 MGD RN: 368087 GED augmented by DFT computations

3,3,4,4-Tetrafluoro-1,2-dimethoxycyclobutene

O

H 3C

Bonds C–H C=C C(1)–C(4) C(2)–C(3) C(3)–C(4) C(3)–F(7) C(4)–F(9) C(1)–O(5) C(2)–O(6) O(5)–C(11) O(6)–C(12)

Cs a,b 1.127(8) e 1.337(21) 1.496(8) 1 1.501(8) 1 1.567(12) 1.375(4) 2 1.368(4) 2 1.318(12) 3 1.340(12) 3 1.405(13) 4 1.504(13) 4

rg [Å] C2v c,d 1.147(8) e 1.336(21) 1.498(8)

C6H6F4O2 Cs (I) C2v (II) O

F

F F

1.563(12) 1.374(4) 1.327(12) 1.449(13) I

CH3

F

614

Angles C(4)–C(1)=C(2) C(1)=C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(1) C(2)=C(1)–O(5) C(1)=C(2)–O(6) C(1)–O(5)–C(11) C(2)–O(6)–C(12) F(9)–C(4)–F(10) F(7)–C(3)–F(8) F(9)–C(4)–C(1) F(7)–C(3)–C(2) F(9)–C(4)–C(3) F(7)–C(3)–C(4) H–C–H X…C(4)–C(3) f X…C(3)–C(4) f Other angle tilt(CH3) g

8 Molecules with Six Carbon Atoms

θα [deg]

Cs a,b 94.6(4) 5 94.2(4) 5 85.6(4) 85.5(4) 135.5(15) 6 131.4(22) 6 119.8(13) 7 119.5(13) 7 104.7(7) 8 104.1(7) 8 118.4(6) 118.5(6) 114.8(4) 115.1(4) 105.1(49) e 133.3(9) 9 133.5(9) 9

Cs -3.6 h

C2v c,d 94.4(4) 85.6(4) 130.0(12) 119.7(13) 104.0(7) 118.7(6) 118.7(6) 105.1(49) e 133.2(9) II

τα [deg]

C2v -3.6 h

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 2σ values and the estimated error due to correlation among the data. b Parameters with equal superscripts were derived from their refined average value and difference. c Uncertainties were assumed equal to those of the Cs conformer. d Differences to corresponding parameters of the Cs conformer were adopted from B3LYP/cc-pVTZ computation. e Average value. f X is the bisector of the adjacent F–C–F angle. g Angle between the C3 axis of the CH3 group and the C–O bond; it is negative when H(1) and H(2) atoms are moving to the oxygen atom. h Adopted from computation at the level of theory as indicated above. According to predictions of computations at the B3LYP level of theory with various basis sets, the title compound exist as a mixture of two conformers, I (Cs point-group symmetry) and II (C2v). The amount of the minor conformer, II, was estimated to be about 10 %. The GED experiment was carried out at Tnozzle = 371 K. The compound was found to exist primarily as the Cs conformer (98(11) %). Harmonic vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. In contrary to elongated single C–C bonds opposite to the double bonds in other fluorinated cyclobutenes, the rg(C(3)–C(4)) in the studied molecule was found to be close to that in cyclobutene itself. Richardson AD, Hedberg K, Lunelli B (2010) The puzzle of bond length variation in substituted cyclobutenes. A new example: Molecular structure and conformations of 1,2-dimethoxy-3,3,4,4-tetrafluorocyclobut-1-ene. J Phys Chem A 114 (16):5358-5364

719 CAS RN: 177191-77-4

Benzene – helium (1/1)

8 Molecules with Six Carbon Atoms

C6H6He C6v

MGD RN: 144657 UV

Distance Rcm b

615

He

r0 [Å] a 3.602(9)

Copyright 2013 with permission from Elsevier [a].

a b

Parenthesized uncertainty in units of the last significant digit. Distance between He and the center-of-mass of the benzene subunit.

The rotationally resolved electronic spectrum of the binary van der Waals complex was recorded by a supersonic-jet mass-selective two-color resonance-enhanced two-photo ionization spectrometer near the S1 ← S0 601 vibronic transition of the benzene monomer at about 38610 cm-1. The Rcm distance was determined from the ground-state rotational constants of the main isotopic species under the assumption that the benzene structure was not changed upon complexation. a. Hayashi M, Ohshima Y (2013) Sub-Doppler electronic spectra of the benzene-(He)n complexes. Chem Phys 419:131-137 IR

Distance Rcm b

r0 [Å] a 3.594(1)

Copyright 2014 with permission from Elsevier [b].

a b

Parenthesized uncertainty in units of the last significant digit. Distance between He and the center-of-mass of the benzene subunit.

The rotationally resolved IR spectrum of the perdeuterated complex was recorded by a supersonic-jet tunable optical parametric oscillator laser spectrometer in the region of the C6D6 ν12 fundamental band and the ν2+ν13 combination band, which are coupled by a Fermi resonance. The Rcm distance was determined from the ground-state rotational constants of this isotopic species under the assumption that the benzene structure was not changed upon complexation. b. George J, McKellar ARW, Moazzen-Ahmadi N (2014) Infrared spectra of He-, Ne-, and Ar-C6D6. Chem Phys Lett 610:121-124

720 CAS RN: 503543-66-6 MGD RN: 144450 UV

Benzene – helium (1/2) C6H6He2 D6h 2 He

Distance Rcm b

a

r0 [Å] 3.596(6)

616

8 Molecules with Six Carbon Atoms

Copyright 2013 with permission from Elsevier.

a b

Parenthesized uncertainty in units of the last significant digit. Distance from He to the center-of- mass of C6H6.

The rotationally resolved electronic spectrum of the complex was recorded in a supersonic jet by a mass-selective two-color resonance-enhanced two-photo ionization spectrometer near the S1 ← S0 601 vibronic transition of the benzene monomer at about 38610 cm-1. The r0 parameter was determined from the ground-state rotational constants of the main isotopic species under the assumption that the benzene structure was not changed upon complexation. Hayashi M, Ohshima Y (2013) Sub-Doppler electronic spectra of the benzene-(He)n complexes. Chem Phys 419:131-137

721 CAS RN: 5455-59-4 MGD RN: 213796 GED combined with MS and augmented by QC computations

2-Nitrobenzenesulfonamide C6H6N2O4S C1 (I) C1 (II) O

Bonds C–H C(1)–C(2) C–C C–S S–N(1) S=O(1) S=O(2) N(1)–H(1) N(1)–H(2) C–N(2) N=O(3) N=O(4) O(3)...H(1)

rh1[Å] a,b 1.071(9) 1.398(4)1 1.390(4)1,c 1.789(8) 1.644(6) 1.424(4) 2 1.430(4) 2 1.015 3 1.013 3 1.487(8) 1.226(4) 4 1.217(4) 4 2.0(3) d

Bond angles C(2)–C(1)–C(6) C(1)–C(2)–C(3) S–C(1)–C(2) N(1)–S–C(1) O(1)=S–C(1) O(1)=S–N(1) H–N–S H–N–H N(2)–C(2)–C(1) O(3)=N(2)–C(2)

θh1 [deg] b,e

Dihedral angles S–C(1)–C(2)–C(3)

τh1 [deg] e

117.3(9) 5 121.5(9) 5 125.2(18) 107.7(32) 106.3(18) 108.9(33) 112.8 113.5 121.7(21) 116.0(3)

173(2)

O S NH2

NO2

8 Molecules with Six Carbon Atoms

N(1)–S–C(1)–C(2) H(1)–N(1)–S=O(1) N(2)–C(2)–C(1)–C(6) O(3)=N(2)–C(2)–C(1) O(3)=N(2)–C(2)…O(4)

617

74(8) 56.5 179(6) -42(6) 177.5

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/6-311+G** computation. c Average value. d Dependent parameter. e Parenthesized uncertainties in units of the last significant digit are 3σ values. The GED experiments were carried out at Teffusion cell=433(5) K. The best fit to experimental intensities was obtained for an approximately equimolar mixture of two conformers, I (52%) and II (48%), characterized by orthogonal position of the S–N bond relative to the ring plane and differing in the magnitude of the C–S–N–H torsional angle, namely, having staggered and eclipsed conformations of the NH2 group relative to the SO2 group, respectively. Both conformers are stabilized due to formation of the H…O hydrogen bond. Differences between structural parameters of the conformers, except those for torsional angles, were fixed at the values from B3LYP/6-311+G** computations. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated with harmonic force constants from computation at the level of theory as indicated above. Structural parameters are presented for conformer I. Giricheva NI, Girichev GV, Medvedeva YS, Ivanov SN, Bardina AV, Petrov VM (2011) Conformational properties of ortho-nitrobenzenesulfonamide in gas and crystalline phases. Intra- and intermolecular hydrogen bond. Struct Chem 22 (2):373-383

722 CAS RN: 177191-78-5 MGD RN: 129170 IR

Distance Rcm b

r0 [Å] a 3.454(91)

Benzene – neon (1/1) C6H6Ne C6v Ne

Copyright 2014 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit. b Distance between Ne and the center-of-mass of the benzene subunit. The rotationally resolved IR spectrum of the perdeuterated complex was recorded by a supersonic-jet tunable optical parametric oscillator laser spectrometer in the region of the C6D6 ν12 fundamental band and the ν2+ν13 combination band, which are coupled by a Fermi resonance. The Rcm distance was determined from the ground-state rotational constants of this isotopic species under the assumption that the benzene structure was not changed upon complexation.

618

8 Molecules with Six Carbon Atoms

George J, McKellar ARW, Moazzen-Ahmadi N (2014) Infrared spectra of He-, Ne-, and Ar-C6D6. Chem Phys Lett 610:121-124

723 CAS RN: 98-11-3 MGD RN: 384014 GED combined with MS and augmented by QC computations

Benzenesulfonic acid C6H6O3S C1

O

Bonds C(1)–C(2) C–C c C–S S–O(1) S=O c O–H C(2)–H C–H

rh1 [Å] a,b 1.402(4) 1.402(4) 1.770(5) 1.623(4) 1 1.438(4) 1 0.870(17) 1.115(6) 1.116(6) c

Bond angles C(1)–C(2)–C(3) C(2)–C(1)–C(6) S–C(1)–C(2) O(1)–S–C(1) O(3)=S–C(1) O(3)=S–O(1) O(2)=S=O(3) O(2)=S–O(1) H–O(1)–S

θh1 [deg] b,d

Dihedral angles S–C(1)–C(2)–C(3) O(1)–S–C(1)–C(2) H–O(1)–S=O(3) C(1)–S–O(1)–H

τh1 [deg] d

O

S OH

118.8(3) 121.6(12) e 122.9(9) 104.0(8) 109.9(5) 106.3(10) 2 120.4(23) 2 105.0(10) 2 117(6)

180.0 f -97.7(44) -20(48) 96(49) e

Copyright 2012 with permission from Elsevier .

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between the parameters in each group were adopted from B3LYP/cc-pVTZ calculation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 2.5σ values. e Dependent parameter. f Assumed. The GED experiment was carried out at Teffusion cell = 396(9) K. According to predictions of MP2 and B3LYP computations (with cc-pVTZ basis set), the barrier to internal rotation of the O–H bond around the S–O(1) bond is comparable with thermal energy at the temperature of the experiment, that points to hindered motion of the O–H group between two enantiomers. The best fit to experimental intensities was obtained for the model with the O–H bond approximately eclipsing the double S=O bond (C1 overall symmetry). The benzene ring was assumed to be planar.

8 Molecules with Six Carbon Atoms

619

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Giricheva NI, Girichev GV, Medvedeva YS, Ivanov SN, Petrov VM, Fedorov MS (2012) Do enantiomers of benzenesulfonic acid exist? Electron diffraction and quantum chemical study of molecular structure of benzenesulfonic acid. J Mol Struct 1023:25-30

724 CAS RN: 5222-73-1 MGD RN: 465164 GED augmented by DFT computations

3,4-Dimethoxy-3-cyclobutene-1,2-dione C 6H 6O 4 C2v (ap-ap) Cs (ap-sp) a

Bonds C–H C(1)=C(2) C(1)–C(4) C(2)–C(3) C(3)–C(4) C(3)=O(7) C(4)=O(8) C(1)–O(5) C(2)–O(6) O(5)–C(9) O(6)–C(10) Bond angles C(1)=C(2)–C(3) C(2)=C(1)–C(4) C(2)–C(3)–C(4) C(1)–C(4)–C(3) C(4)–C(3)=O(7) C(3)–C(4)=O(8) C(2)–C(3)=O(7) C(1)–C(4)=O(8) C(2)=C(1)–O(5) C(1)=C(2)–O(6) C(1)–O(5)–C(9) C(2)–O(6)–C(10) O–C–H

rα [Å] ap-ap ap-ap 1.089(17) b 1.089(17) b 1.376(9) 1.376(9) 1.487(11) 1.489(11) 1.489(11) 1.535(20) 1.537(20) 1.187(4) 1.186(4) 1.182(4) 1.307(6) 1.306(6) 1.315(6) 1.407(9) 1.402(9) 1.407(9)

ap-ap 93.1(5)

a

rg [Å] ap-sp ap-sp 1.107(17) b 1.107(17) b 1.381(9) 1.381(9) 1.495(11) 1.493(11) 1.495(11) 1.545(20) 1.543(20) 1.204(4) 1.203(4) 1.197(4) 1.314(6) 1.316(6) 1.325(6) 1.439(9) 1.444(9) 1.446(9)

H 3C

θα [deg] a

86.9(5) 136.7(29) 136.4(29) 131.0(23) 117.1(12) 109.9(30) b

ap-sp 93.0(5) 93.2(5) 87.0(5) 86.8(5) 137.0(29) 136.8(29) 136.0(29) 136.4(29) 137.5(23) 131.8(23) 118.2(12) 116.9(12) 109.9(30) b

Reprinted with permission. Copyright 2014 American Chemical Society.

ap-ap

sp-ap

O

O

O

O

CH3

620

8 Molecules with Six Carbon Atoms

a

Parenthesized uncertainties in units of the last significant digit are 3σ values and include the effects of correlation among the data. Uncertainties for rg parameters were assumed to be the same as for rα. b Average value. At Tnozzle = 458 K, the title compound was found to exist as a mixture of two conformers, ap-ap and ap-sp, in amounts of 68(24) and 32(24) %, respectively. In the ap-ap conformer, both methyl groups are antiperiplanar to the double C=C bond, whereas in the ap-sp conformer, one methyl group is synperiplanar with respect to the C=C bond and the other one is antiperiplanar. Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Costello LL, Hedberg L, Hedberg K (2015) Molecular structure and conformations of 1,2dimethoxycyclobutene-3,4-dione. An electron-diffraction investigation augmented by quantum mechanical and normal coordinate calculations. J Phys Chem A 119 (9):1563-1567

725 CAS RN: 185009-27-2 MGD RN: 148435 MW supported by ab initio calculations

Fluorobenzene – water (1/1) C6H7FO Cs

F

O

Distance H(1)…O(2)

r0 [Å] a 2.511(4)

Angles C–H(1)…O(2)

θ0 [deg] a

βb

H

H

138.70(7) 119(4)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. b Angle between H(1)…O(2) and the C2 axis of the water subunit. The rotational spectra of the title complex were recorded by a pulsed-jet FTMW spectrometer in the spectral region between 3 and 15 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, 18 O, D and D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The determined structure corresponds to a planar (or nearly planar) configuration of the complex. The observed tunneling splittings of the rotational lines indicated the hindered internal rotation of the water subunit about its C2 axis. The barrier height was determined to be 360 cm-1. Brendel K, Mäder H, Xu Y, Jäger W (2011) The rotational spectra of the fluorobenzene⋅⋅⋅water and pdifluorobenzene⋅⋅⋅water dimers: Structure and internal dynamics. J Mol Spectrosc 268(1-2):47-52

726 CAS RN: 238754-16-0 MGD RN: 215243 MW augmented by

1,4-Difluorobenzene – ammonia (1/1) C6H7F2N Cs

8 Molecules with Six Carbon Atoms

621

ab initio calculations

F N

Distances Rcm b N…H(1) H(2)…F

r0 [Å] a 3.792 c 2.48(1) 2.469 c

Angle C–H(1)…N

θ0 [deg] a

H

H H

F

145.8(1)

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainty in units of the last significant digit. Distance between the centers of mass of the subunits. c Dependent parameter. b

The rotational spectrum of the title complex was recorded by a pulsed supersonic jet FTMW spectrometer in the region 6 to 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of the main isotopic species; the remaining structural parameters were fixed to the values from MP2/6-311++G** calculations. The subunits of the complex were found to be linked by two weak hydrogen bonds. The nitrogen atom is located in the plane of the aromatic ring, i.e. the complex is adopting a σ configuration. Giuliano BM, Evangelisti L, Maris A, Caminati W (2010) Weak hydrogen bonds in σ-1,4-difluorobenzeneammonia: A rotational study. Chem Phys Lett 485(1-3):36-39

727 CAS RN: MGD RN: 418789 MW augmented ab initio calculations

Distances Rcm b N…H F…H

r0 [Å] a 3.151(1) 2.873 c 2.569 c

Angle

θ0 [Å] a

ϕ

d

Pyridine – difluoromethane (1/1) C6H7F2N Cs H

N

F

H

F

84.9(1)

Copyright 2013 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Dependent parameter. d Angle between Rcm and C–F. b

The rotational spectrum of the binary complex was recorded by a pulsed-jet FTMW spectrometer in the spectral range between 6 and 18 GHz.

622

8 Molecules with Six Carbon Atoms

Only one conformer, predicted by MP2/6-311++G(d,p) calculations to be the most stable one, was identified. Two further conformers, differing in the orientation of the CH2F2 subunit relative to the ring, were predicted to be higher in energy by 1.6 and 4.7 kJ mol-1. The partial r0 structure was obtained from the ground-state rotational constants of two isotopic species (main and 15 N); the remaining structural parameters were assumed at the values from calculations at the level of theory as indicated above. Vallejo-López M, Spada L, Gou Q, Lesarri A, Cocinero EJ, Caminati W (2014) Interactions between freons and aromatic molecules: The rotational spectrum of pyridine-difluoromethane. Chem Phys Lett 591:216-219

728 CAS RN: 15066-28-1 MGD RN: 492690 MW augmented by ab initio calculations

Pyridine – formic acid (1/1) C6H7NO2 Cs O

Distances N(1)…O(1) N(1)…H(1) b O(2)…H(3) b

r0 [Å] a 2.662(1) 1.661 2.460

Angles N(1)…O(1)–C(2) N(1)…H(1)–O(1) b C(3)–H(3)…O(2) b

θ0 [deg] a

N

H

OH

111.4(1) 175.3 132.0

Reprinted with permission. Copyright 2016 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectra of the binary complex of pyridine with formic acid were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 6 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, two D and 15N) assuming that the remaining structural parameters were constrained to the values from MP2/6311++G(d,p) calculations. Spada L, Gou Q, Giuliano BM, Caminati W (2016) Interactions between carboxylic acids and heteroaromatics: A rotational study of formic acid-pyridine. J Phys Chem A 120(27):5094-5098

729 CAS RN: 638-21-1 MGD RN: 329511 GED augmented by ab initio computations

Bonds P–C P–H C(1)–C(2)

Phenylphosphine C6H7P Cs (see comment) PH2

rh1 [Å] a 1.838(3) 1.415(3) b 1.399(4) b

8 Molecules with Six Carbon Atoms

C(2)–C(3) C(3)–C(4) C–H Bond angles H–P–H C–P–H P–C–C C(2)–C(1)–C(6) C(3)–C(4)–C(5) C(2)–C(3)–C(4) C(1)–C(2)–C(3) C(4)–C(3)–H C(1)–C(2)–H

623

1.392(3) b 1.397(4) b 1.115(5) c

θh1 [deg] a 94.6(10) c 96.8(9) c 124.2(7) 118.7(3) 119.3(3) 120.3(4) d 120.7(3) d 119.8(9) c 120.5(9) c

Reprinted with permission. Copyright 2009 American Chemical Society [a].

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Derived from the refined average value of r(P–H) and r(C–C) and differences between these distances restrained to the values from MP2/6-311++G**computation. c Restrained to the value from computation as indicated above. d Dependent parameter. b

Molecular structure from Ref. [b] was reinvestigated. According to prediction of ab initio computations, rotation of the PH2 group around the P–C bond is close to free. However, application of a dynamic model for description of this large-amplitude motion did not improve the fit to experimental intensities. Therefore, a rigid model of single conformer with Cs symmetry was applied in the GED analysis neglecting the effects of the large-amplitude torsion. The GED experiment was carried out at Tnozzle = 293 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/6-311++G** computation. a. Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612 b. Naumov VA, Tafipol’skii NA, Samdal S (2003) Molecular structure of phenylphosphine and its analogs by gas-phase electron diffraction and quantum-chemical calculations. Russ J Gen Chem (Engl Transl)/Zh Strukt Khim 73/73(6/6):896-902/948-954.

730

(3E)-1,3,5-Hexatriene

trans-1,3,5-Hexatriene C 6H 8 C2h

CAS RN: 2235-12-3

MGD RN: 673555 IR augmented by ab initio calculations H 2C

Bonds C(1)=C(2) C(2)–C(3) C(3)=C(4) C(1)–Htrans b C(1)–Hcis b C(2)–H C(3)–H

r see [Å] a 1.3390(8) 1.4494(7) 1.3461(14) 1.0823(9) 1.0793(9) 1.0844(9) 1.0854(9)

CH2

624

8 Molecules with Six Carbon Atoms

Bond angles C(1)=C(2)–C(3) C(2)–C(3)=C(4) C(2)=C(1)–Htrans b C(2)=C(1)–Hcis b C(1)=C(2)–H C(3)–C(2)–H C(4)=C(3)–H C(5)–C(4)–H H–C(1)–H

θ see [deg] a

123.6(4) 123.67(8) 121.02(8) 121.45(9) 119.65(9) 116.68(8) 119.19(9) 117.14(11) 117.54(11)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. C(1)–Hcis and C(1)–Htrans are the bonds in the cis and trans positions relative to the C(2)–C(3) bond, respectively. b

The semiexperimental equilibrium structure r see was determined from the previously published experimental ground-state rotational constants of eight isotopic species by taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields.

Craig NC, Demaison J, Groner P, Rudolph HD, Vogt N (2015) Electron delocalization in polyenes: A semiexperimental equilibrium structure for (3E)-1,3,5-hexatriene and theoretical structures for (3Z,5Z)-, (3E,5E)-, and (3E,5Z)-1,3,5,7-octatetraene. J Phys Chem A 119(1):195-204

731 CAS RN: 1264531-21-6 MGD RN: 412503 UV

Distance Rcm b

ortho-H2 r0 [Å] a 3.46(2)

Benzene – dihydrogen (1/1) C 6H 8 C6v

para-H2 r0 [Å] a 3.2(2)

H

H

Reprinted with permission. Copyright 2013 American Chemical Society.

a b

Parenthesized uncertainty in units of the last significant digit is 3σ value. Distance between the centers of mass of the monomer subunits.

The rotationally resolved UV spectrum of the binary van der Waals complex of benzene with dihydrogen was recorded in the region of the S1←S0 601 vibronic transition of the benzene monomer. The partial r0 structure was determined from the ground-state rotational constants under the assumption that the structural parameters were not changed upon complexation. Hayashi M, Ohshima Y (2013) Sub-Doppler electronic spectra of benzene-(H2)n complexes. J Phys Chem A 117(39):9819-9830

8 Molecules with Six Carbon Atoms

625

732 CAS RN: MGD RN: 418600 MW augmented by ab initio calculations

Distances Rcm b N…H F…H

r0 [Å] a 3.592(6) 2.67 2.37

Angle

θ0 [deg] a

α

c

Pyridine – fluoromethane (1/1) C6H8FN Cs H

H

N

H

F

81.6(5)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainty in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Angle between Rcm and C–F. b

The rotational spectra of the binary complex of pyridine with fluoromethane were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 18 GHz. The partial r0 structure was determined by adjusting two structural parameters of the MP2/6-311++G(d,p) structure to the experimental ground-state rotational constants of four isotopic species (main, 15N, D3 and 15 N/D3). Spada L, Gou Q, Vallejo-López M, Lesarri A, Cocinero EJ, Caminati W (2014) Weak C-H⋅⋅⋅N and C-H⋅⋅⋅F hydrogen bonds and internal rotation in pyridine-CH3F. Phys Chem Chem Phys 16(5):2149-2153

733 CAS RN: 4160-72-9 MGD RN: 419725 GED supported by ab initio computations

Bonds N(1)–C(2) C(2)–N(3) N(3)–C(4) C(4)–C(5) N(1)–C(6) C(5)–C(9) N(1)–C(10) C(2)=O(7) C(4)=O(8) C(6)–H C(9)–Hʹ C(9)–Hʹʹ N(3)–H C(10)–Hʹ C(10)–Hʹʹ C(5)=C(6)

1,5-Dimethyl-2,4(1H,3H)-pyrimidinedione 1-Methylthymine C6H8N2O2 Cs O

re [Å] 1.378(2) 1 1.377(2) 1 1.393(2) 1 1.461(3) 2 1.379(2) 1 1.495(3) 2 1.455(3) 2 1.216(2) 3 1.217(2) 3 1.082(5) 4 1.089(5) 4 1.090(5) 4 1.010(5) 4 1.087(5) 4 1.088(5) 4 1.350(30) c

CH3

HN

a,b

O

N

CH3

626

8 Molecules with Six Carbon Atoms

θe [deg] a

Bond angles N(1)–C(2)–N(3) C(2)–N(3)–C(4) N(3)–C(4)–C(5) C(2)–N(1)–C(6) N(1)–C(2)=O(7) N(3)–C(4)=O(8) C(6)=C(5)–C(9) C(2)–N(1)–C(10) C(2)–N(3)–H N(1)–C(6)–H N(1)–C(10)–Hʹ N(1)–C(10)–Hʹʹ C(5)–C(9)–Hʹ C(5)–C(9)–Hʹʹ C(4)–C(5)=C(6) N(1)–C(6)=C(5) N(3)–C(2)=O(7) C(5)–C(4)=O(8) C(4)–C(5)–C(9) C(6)–N(1)–C(10)

114.2(7) 128.0(4) 114.5(5) 121.6(5) 122.4(11) 121.0(8) 123.4(14) 118.3(11) 115.1 d 114.7 d 108.3 d 110.2 d 110.8 d 110.6 d 117.7(9) c 124.0(12) c 123.4(14) c 124.5(9) c 119.0(16) c 120.1(12) c

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the computed values of CCSD(T)_ae/cc-pwCVQZ quality (see comment below). c Dependent, i.e. derived parameter. d Assumed at the value computed at the level of theory as indicated above. b

The GED experiment was carried out at 458(3) K. The torsion of the methyl group around the C−N(1) bond could not be described by a static model and was considered as a large-amplitude motion. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2/cc-pVTZ quadratic and cubic force constants by taking into account non-linear kinematic effects. The structure obtained by optimization at the CCSD(T)_ae/cc-pwCVTZ level of theory with the following extrapolation to the quadruple-ζ basis set agrees well with the semiexperimental equilibrium structure determined from the GED data. Vogt N, Marochkin II, Rykov AN (2015) From the determination of the accurate equilibrium structure of 1methylthymine by gas electron diffraction and coupled cluster computations to the observation of methylation and flexibility effects in pyrimidine nucleobases. J Phys Chem A 119 (1):152-159

734 CAS RN: 227760-40-9 MGD RN: 489727 MW augmented by ab initio calculations

Distances Rcm b N(1)…H(1)

r0 [Å] a 5.2751(1) 1.960 c

1H-Imidazole dimer C6H8N4 C1 N

N H

2

8 Molecules with Six Carbon Atoms

Angles N(1)…H(1)–N

θ0 [deg]

Other angles

τ0 [deg] a 87.9(4) 122.3(54) 90 g 106.3(50)

d

γ βe φf ϕf

627

169.3 c

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the center-of-mass of the monomer. c Dependent parameter. d Twist angle describing rotation of one monomer unit with respect to the other about the Rcm line. e Turning of the monomer unit in the plane of itself. f φ andϕ are polar and azimuthal angles, respectively, used to locate the position of the center-of-mass of one monomer with respect to the other. g Assumed at the value from the partial optimization at the CCSD(T)(F12*)/cc-pVDZ-F12 level. b

The rotational spectrum of the title dimer was recorded in the 6 - 18 GHz frequency range using a broadband chirped-pulse FTMW spectrometer. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, D, D2 and D8); the geometries of the monomer subunits were assumed to be unchanged upon complexation, except for the pyrrolic N–H(1) bond, for which the change was assumed at the value calculated at the level as above. Mullaney JC, Zaleski DP, Tew DP, Walker NR, Legon AC (2016) Geometry of an isolated dimer of imidazole characterized by rotational spectroscopy and ab initio calculations. ChemPhysChem 17(8):1154-1158

735 CAS RN: 10316-66-2 MGD RN: 375160 GED augmented by QC calculations

Bonds O–H C–H C(1)=O C(2)=C(3) C(4)–C(5) C(1)–C(6) C(1)–C(2)

2-Hydroxy-2-cyclohexen-1-one C 6H 8O 2 C1 O

rg [Å] a 0.970 b 1.103(7) 1.224(3) 1.357(2) 1.534(5) 1.511(3) 1.489(2) c

OH

628

8 Molecules with Six Carbon Atoms

C(3)−C(4) C(2)−O C(5)−C(6)

1.508(2) c 1.358(2) c 1.533(5) c

Bond angles C(1)–C(2)=C(3) C(6)–C(1)–C(2) H–C(3)=C(2) H–C–C H–O–C C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(2)=C(3)–C(4) O=C(1)–C(2) O–C(2)–C(1) O–C(2)=C(3) O=C(1)–C(6)

θα [deg] a

Dihedral angles H–O–C(2)–C(1) C(3)=C(2)–C(1)–C(6) C(1)–C(2)=C(3)–C(4) C(2)=C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–C(1) C(5)–C(6)–C(1)–C(2)

τα [deg] a

121.2(2) 117.6(3) 118.3 b 109.4 b 104.0 b 113.9(8) c 108.4(10) c 112.4(5) c 121.2(2) c 119.3(3) c 115.3(3) c 123.4(4) c 123.1(6) c

0.0 b 2.4 b 2.8 b -22.8(9) 50.8(16) c -53.3(16) c 32.5(10) c

Copyright 2009 with permission from Elsevier [a].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Assumed. c Dependent parameter. b

The GED experiment was carried out at Tnozzle = 295 K. The 1,2-cyclohexanedione sample was found to exist as a pure enol form with non-planar ring (C(5) atom is out of the plane formed by the other carbon atoms). This tautomer, stabilized by a hydrogen bond, was predicted to be lower in energy than the diketo tautomer and the enol tautomer without hydrogen bond by 1.6 and 6.5 kcal mol−1, respectively (MP2/6-311G(d,p)). Vibrational corrections to the experimental internuclear distances, ∆rα = ra − rα, were calculated using harmonic force constants from B3LYP/6-311G(d,p) computation. Small differences between related parameters were adopted from MP2 computations. a. Shen Q, Traetteberg M, Samdal S (2009) The molecular structure of gaseous 1,2 cyclohexanedione. J Mol Struct 923 (1-3):94-97 MW augmented by ab initio calculations

Bonds C(2)=C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1)

C1

r0 [Å] a 1.368 1.502 1.530 b 1.534 1.510

8 Molecules with Six Carbon Atoms

C(1)–C(2) C(1)=O C(2)–O C(3)–H C(4)–H(eq) c C(4)–H(ax) c C(5)–H(ax) c C(5)–H(eq) c C(6)–H(ax) c C(6)–H(eq) c O–H

1.479 1.229 b 1.356 b 1.088 b 1.096 b 1.101 b 1.097 b 1.095 b 1.100 b 1.094 b 0.971 b

Bond angles C(2)=C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(1)–C(2)=C(3)

θ0 [deg] a

Dihedral angles C(3)–C(4)–C(5)–C(6) C(3)=C(2)–C(1)–C(6)

τ0 [deg] a

629

121 112 110 110 117 121

53 -17

Reprinted with permission. Copyright 2014 American Chemical Society [b].

a

Uncertainties were not given in the original paper. Constrained to the value from MP2/6-311++G** calculation. c H(eq) ant H(ax) are equatorial and axial H atoms, respectively. b

Only the monoenolic form was detected in the vapor of 1,2-cyclohexanedione by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 14 GHz. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, D and six 13C); the remaining structural parameters were constrained to the ab initio values (see above). b. Pejlovas AM, Barfield M, Kukolich SG (2015) Microwave measurements of the spectra and molecular structure for the monoenolic tautomer of 1,2-cyclohexanedione. J Phys Chem A 119(9):1464-1468

736 CAS RN: 504-02-9 MGD RN: 387956 GED augmented by QC computations

1,3-Cyclohexanedione C 6H 8O 2 Cs (chair) C2 (boat) O

Bond lengths C–H C=O C(1)–C(2) C(3)–C(4) C(4)–C(5)

rg [Å] a chair boat 1.105(5) b 1.105 b,c 1.220(2) 1.220 c 1.528(2) 1.528 c d 1.520 1.528 d d 1.538 1.532 d

O

630

8 Molecules with Six Carbon Atoms

Bond angles C(1)–C(2)–C(3) C(6)–C(1)–C(2) H–C–C O=C(1)–C(2) O=C(1)–C(6) C(3)–C(4)–C(5) C(4)–C(5)–C(6) Dihedral angles C(3)–C(2)–C(1)–C(6) flap g C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6)

θα [deg] a

chair 114.0(8) 116.2(5) 109.6(7) 121.4 e,f 122.4 111.7(9) e 112.3 e

boat 115.0 e 117.2 109.6(7) 120.9 e,f 121.9 111.2 e 111.6 e

τα [deg] a

chair -40.1(14) 143.8 h 40.1(14) e -47.2(9) e 53.8(8) e

boat 33.6(20) 241.8 h -33.1 e -11.0 e 56.9 e

Reprinted with permission. Copyright 2011 American Chemical Society.

chair

boat

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Average value. c Assumed to be equal in both conformers. d Difference to C(1)–C(2) bond lengths was adopted from MP2/6-311G(d,p) computation. e Dependent parameter. f Difference to O=C(1)–C(6) angle was assumed at the value from computation as above. g Dihedral angle between the C(4)C(5)C(6) and C(4)C(6)C(2) planes. h Assumed. b

At Tnozzle = 379 K, the title compound was found to exist as a mixture of the twist (70(9)%) and chair (30(9)% conformers. According to MP2/6-311G(d,p) computation, the twist conformer is lower in energy than the chair conformer by 1.34 kcal mol−1. Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using the B3LYP/6-311G(d,p) quadratic force field. Shen Q, Samdal S (2011) The molecular structures and conformational compositions of 1,3-cyclohexanedione and 1,4-cyclohexanedione as determined by gas-phase electron diffraction and theoretical calculation. J Mol Struct 1005 (1-3):156-160

737 CAS RN: 637-88-7 MGD RN: 125434

1,4-Cyclohexanedione C 6H 8O 2

8 Molecules with Six Carbon Atoms

631

GED augmented by DFT computations

rg [Å] a twisted boat b chair 1.115(11) 1.124(11) 1.211(3) 1.233(6) 1.524(5) 1.526(5) 1.533(11) 1.539(11)

Bonds C–H C=O C(1)–C(2) C(2)–C(3)

chair

θα [deg] a

Bond angles C(1)–C(2)–H(7) C(3)–C(2)–H(7) C(1)–C(2)–H(8) C(3)–C(2)–H(8) C(1)–C(2)–C(3) C(6)–C(1)–C(2) C(2)–C(1)=O C(6)–C(1)=O Dihedral angle O=C…C=O

D2 (twisted boat) C2h (chair)

c

twisted boat b 108.9(5) 113.2(7) 107.3(9) 112.0(8) 111.1(5) 116.3(8) 122.4(4) 121.4(3)

chair 108.0(4) 110.9(8) 107.9(9) 111.3(8) 111.0(4) 115.7(8) 122.2(4) 122.2(4)

τα [deg] a

twisted boat b 158.7(1)

twisted boat

chair 180.0

Reprinted with permission. Copyright 2013 American Chemical Society [a].

a

Parenthesized uncertainties in units of the last significant digit are 2σ values. Averaged values of the D2 form and all pseudo-conformers with C2 symmetry. Differences between parameters of the D2 and C2h configurations were fixed at the values from computation at the level of theory as indicated below. c Dihedral angle between the C=O bond vectors. b

The GED experiment was carried out at Tnozzle = 435 K. The structure of the title molecule was investigated applying a dynamic model. The best fit to experimental intensities was obtained for a mixture of the chair conformer with C2h symmetry and the boat conformer twisted from its equilibrium configuration with D2 symmetry. The ratio of the conformers was determined to be twisted boat : chair = 76(10) : 24(10) (in %). Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. a. Frogner M, Johnson RD, Hedberg L, Hedberg K (2013) 1,4-Cyclohexanedione. Composition, molecular structures, and internal dynamics of the vapor: An electron diffraction investigation augmented by molecular orbital calculations. J Phys Chem A 117 (43):11101-11106

GED augmented by QC computations

Bonds C–H C=O

D2 (twist) C2h (chair)

rg [Å] a twist chair 1.116(5) b 1.117(5) b 1.220(2) 1.220(2)

632

C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) Bond angles C–C–H C(1)–C(2)–C(3) C(6)–C(1)–C(2) C(2)–C(1)=O C(3)–C(4)–C(5) C(4)–C(5)–C(6) Dihedral angles C(3)–C(2)–C(1)–C(6) flap d C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6)

8 Molecules with Six Carbon Atoms

1.528(8) 1.535(17) 1.528 c 1.528 c

1.525(8) 1.545(17) 1.524 c 1.524 c

θα [deg] a

twist 108.3(7) 113.3(10) 117.9(20) 121.0(3) c 117.9 c 113.3 c

twist 24.6(3) 180.0 49.5(5) c 24.6(6) c 24.6(6) c

chair 108.3(7) 109.5(5) 115.5(10) 122.2(6) c 115.5 c 109.5 c

τα [deg] a

chair 55.8(5) 230.4(32) 52.4(7) c 55.8(5) c 55.8(7) c

Copyright 2011 with permission from Elsevier [b].

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Average value. c Dependent parameter. d Dihedral angle between the C(3)C(4)C(5) and C(3)C(5)M planes, where M is the middle of the C(2)… C(6) distance. b

The GED experiment was carried out at Tnozzle = 383 K. The title compound was found to exist as a mixture of the twist (70(9)%) and chair (30(9)% conformers. According to prediction of MP2/6-311G(d,p) computation, the twist conformer is lower in energy than the chair conformer by 0.55 kcal mol−1. Vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using harmonic force constants from B3LYP/6-311G(d,p) computation. b. Shen Q, Samdal S (2011) The molecular structures and conformational compositions of 1,3 cyclohexanedione and 1,4 cyclohexanedione as determined by gas-phase electron diffraction and theoretical calculation. J Mol Struct 1005 (1-3):156-160

738 CAS RN: 4254-02-8 MGD RN: 182490 MW augmented by QC calculations

Bonds C(6)≡N(8) C(1)–C(6) C(1)–C(2) C(2)–C(4)

Cyclopentanecarbonitrile Cyanocyclopentane C 6H 9N Cs (equatorial) Cs (axial)

equatorial r0 [Å] a 1.160(3) 1.463(3) 1.543(3) 1.540(3)

axial r0 [Å] a 1.160(3) 1.469(3) 1.545(3) 1.541(3)

C

N

8 Molecules with Six Carbon Atoms

633

C(4)–C(5) C(1)–H(7) C(2)–H(2) C(2)–H(1) C(4)–H(2) C(4)–H(1)

1.552(3) 1.098(2) 1.095(2) 1.093(2) 1.092(2) 1.094(2)

1.553(3) 1.094(2) 1.093(2) 1.095(2) 1.093(2) 1.093(2)

Bond angles C(1)–C(6)≡N(8) C(2)–C(1)–C(6) C(2)–C(1)–C(3) C(1)–C(2)–C(4) C(2)–C(4)–C(5) H(7)–C(1)–C(6) H(7)–C(1)–C(2) H(2)–C(2)–C(1) H(2)–C(2)–C(4) H(1)–C(2)–C(1) H(1)–C(2)–C(4) H(1)–C(2)–H(2) H(2)–C(4)–C(2) H(2)–C(4)–C(5) H(1)–C(4)–C(2) H(1)–C(4)–C(5) H(2)–C(4)–H(1)

θ0 [deg] a

θ0 [deg] a

Dihedral angles C(2)–C(1)–C(3)–C(5) C(2)–C(4)–C(5)–C(3)

τ0 [deg] a

τ0 [deg] a

179.0(5) 113.1(5) 103.0(5) 104.1(5) 106.3(5) 108.2(5) 109.7(5) 108.4(5) 106.4(5) 112.9(5) 116.6(5) 108.0(5) 111.2(5) 113.8(5) 110.0(5) 108.2(5) 107.2(5)

38.7(5) 0.0(5)

178.9(5) 110.1(5) 102.1(5) 104.8(5) 106.0(5) 108.5(5) 113.0(5) 113.1(5) 114.9(5) 107.6(5) 107.9(5) 108.2(5) 110.0(5) 108.7(5) 111.3(5) 113.5(5) 107.3(5)

-38.9(5) 0.0(5)

Copyright 2015 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

equatorial

axial

The envelope-equatorial and envelope-axial conformers were identified in the temperature-dependent IR vibrational spectra. The percentage of the axial conformer was estimated for ambient temperature to be 45(1) %. The r0 structural parameters of each of these conformers were obtained by adjusting of the MP2_full/6311+G(d,p) structures to the ground-state rotational constants of one isotopic species. Sawant DK, Klaassen JJ, Gounev TK, Durig JR (2015) r0 Structural parameters, conformational, vibrational studies and ab initio calculations of cyanocyclopentane. Spectrochim Acta A 151:468-479

634

8 Molecules with Six Carbon Atoms

739 CAS RN: 68498-54-4 MGD RN: 409340 MW augmented by QC calculations

Isocyanocyclopentane C 6H 9N Cs (axial) N

Bonds C(4)≡N C(1)–N C(1)–C(2) C(2)–C(3) C(3)–C(3') C(1)–H C(2)–H(1) C(2)–H(2) C(3)–H(1) C(3)–H(2)

r0 [Å] a 1.176(3) 1.432(3) 1.534(3) 1.542(3) 1.554(3) 1.092(2) 1.092(2) 1.095(2) 1.093(2) 1.092(2)

Bond angles C(1)–N≡C(4) C(2)–C(1)–N C(2)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(3') H–C(1)–N H–C(1)–C(2) H(1)–C(2)–C(1) H(1)–C(2)–C(3) H(2)–C(2)–C(1) H(2)–C(2)–C(3) H(1)–C(2)–H(2) H(1)–C(3)–H(2) H(1)–C(3)–C(3') H(2)–C(3)–C(2) H(2)–C(3)–C(3') H(1)–C(3)–H(2)

θ0 [deg] a

Dihedral angles C(2')–C(1)–C(2)–C(3) C(2)–C(3)–C(3')–C(2')

τ0 [deg] a

C

177.8(5) 110.4(5) 102.9(5) 103.6(5) 105.9(5) 108.0(5) 112.5(5) 112.6(5) 115.9(5) 107.5(5) 108.4(5) 108.4(5) 110.0(5) 109.6(5) 111.3(5) 112.6(5) 107.4(5)

40.7(5) 0.0

Copyright 2014 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

The envelope-axial and envelope-equatorial conformers were identified in the temperature-dependent IR vibrational spectra. The percentage of the equatorial conformer was estimated for ambient temperature to be 38(1) %. The rotational spectrum was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 11 and 21 GHz. The r0 structure of the axial conformer was determined by fitting the MP2_full/6311+G(d,p) structure to the ground-state rotational constants of one isotopic species.

8 Molecules with Six Carbon Atoms

635

Durig JR, Klaassen JJ, Sawant DK, Deodhar BS, Panikar SS, Gurusinghe RM, Darkhalil ID, Tubergen MJ (2015) Microwave, structural, conformational, vibrational studies and ab initio calculations of isocyanocyclopentane. Spectrochim Acta A 136:3-15

740 CAS RN: 1186195-50-5 MGD RN: 211430 MW supported by ab initio calculations

Distance Rcm b

Pyridine – methane (1/1) C 6H 9N Cs H

re [Å] a 3.642(1)

N

H

H

H

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainty in units of the last significant digit. Distance between the centers of mass of the monomer subunits.

The rotational spectrum of the binary complex of pyridine with methane was recorded by a pulsed-jet BalleFlygare type FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The separation of both monomer subunits was determined from a pseudo-diatomic Lennard-Jones potential. The complex is formed by a weak hydrogen bond between methane and the π-electron system of pyridine. Gou Q, Spada L, Vallejo-López M, Lesarri A, Cocinero EJ, Caminati W (2014) Interactions between alkanes and aromatic molecules: a rotational study of pyridine-methane. Phys Chem Chem Phys 16(26):13041-13046

741 CAS RN: 1442122-41-9 MGD RN: 418220 UV

Distance Rcm b

ortho-H2 r0 [Å] a 3.444(12)

Benzene – dihydrogen (1/2) C6H10 D6h

para-H2 r0 [Å] a 3.2(2)

Reprinted with permission. Copyright 2013 American Chemical Society.

a b

Parenthesized uncertainty in units of the last significant digit is 3σ value. Distance between the centers of mass of benzene and hydrogen.

H

H

2

636

8 Molecules with Six Carbon Atoms

The rotationally resolved UV spectrum of the ternary van der Waals complex of benzene with dihydrogen was recorded in the region of the S1←S0 601 vibronic transition of the benzene monomer. The partial r0 structure was determined from the ground-state rotational constants under the assumption that the structural parameters were not changed upon complexation. Hayashi M, Ohshima Y. (2013) Sub-Doppler electronic spectra of benzene-(H2)n complexes. J Phys Chem A 117(39):9819-9830

742 CAS RN: 1463883-89-7 MGD RN: 354102 MW

Distance Rcm b

7-Oxabicyclo[4.1.0]heptane – argon (1/1) Cyclohexene oxide – argon (1/1) C6H10ArO C1 Ar

O

r0 [Å] a 3.868(2)

Reprinted with permission. Copyright 2013 American Chemical Society.

a b

Parenthesized uncertainty in units of the last significant digit. Distance between Ar and the center-of-mass of the cyclohexene oxide subunit.

The rotational spectrum of the binary van der Waals complex of cyclohexene oxide with argon was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6.5 and 20 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main and six 13C) under the assumption that the structural parameters of the cyclohexene oxide subunit were not changed upon complexation. Frohman DJ, Novick SE, Pringle WC (2013) Rotational spectrum and structure of cyclohexene oxide and the argon-cyclohexene oxide van der Waals complex. J Phys Chem A 117(50):13691-13695

743 CAS RN: 1530-87-6 MGD RN: 540771 GED combined with MS and augmented by QC computations

1-Piperidinecarbonitrile N-Cyanopiperidine C6H10N2 Cs (equatorial) Cs (axial) N

Bonds N(1)–C(1) N(1)–C(6) C(6)≡N(2) C(1)–C(3) C(3)–C(5) C(1)–H b C(1)–H c Bond angles

C

N

a

rh1 [Å] equatorial axial 1.474(4) 1.477(4) 1.354(3) 1.356(3) 1.179(2) 1.180(2) 1.529(3) 1.533(3) 1.535(3) 1.538(3) 1.106(2) 1.100(2) 1.096(2) 1.096(2)

θh1 [deg] d

equatorial

axial

equatorial

8 Molecules with Six Carbon Atoms

N(1)–C(1)–C(3) C(1)–C(3)–C(5) C(3)–C(5)–C(4) C(1)–N(1)–C(2) C(1)–N(1)–C(6) N(1)–C(6)≡N(2)

Dihedral angles N(1)–C(1)–C(3)–C(5) C(1)–C(3)–C(5)–C(4) Flap1 e Flap2 g ϕh

637

109.5(5) 110.1(5) 112.9(5) 112.8(13) 114.4(5) 185.3(16)

112.1(5) 110.0(5) 113.1(5) 111.4(13) 115.9(8) 185.2(16)

τh1 [deg] d

equatorial 55.1(14) -51.9(14) 56(2) f 48(2) f 15(3) f

axial 54.2(14) -50.9(14) 52(2) f 47(2) f 88(3) f

axial

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Axial H atom. c Equatorial H atom. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Angle between the C(1)–N(1)–C(2) and C(1)–C(3)...C(4)–C(2) planes. f Dependent parameter. g Angle between the C(3)–C(5)–C(4) and C(1)–C(3)...C(4)–C(2) planes. h Angle between the C≡N bond and the C(1)–C(3)...C(4)–C(2) plane. According to predictions of QC computations, the title compound exists as a mixture of two conformers with a chair conformation of the piperidine ring and differing by location of the cyano group (equatorial vs. axial). The GED experiment was carried out at Teffusion cell = 305(3) K). The ratio of the conformers was determined to be equatorial : axial = 52(6) : 48(6) (in %). The corresponding free energy difference ∆G of 0.05(15) kcal mol-1 agrees well with prediction of ∆E = 0.26 kcal mol-1 at the CCSD(T)-F12/CBS level of theory. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from MP2/6-311G** computations. Shlykov SA, Phien TD, Weber PM (2017) Intramolecular inversions, structure and conformational behavior of gaseous and liquid N-cyanopiperidine. Comparison with other 1-cyanoheterocyclohexanes. J Mol Struct 1138:41-49

744 CAS RN: 7491-74-9 MGD RN: 214154 GED augmented by QC computations

2-Oxo-1-pyrrolidineacetamide C6H10N2O2 C1 O O

Bonds C(3)–C(4) C(4)–C(5) C(5)–N(1) C(2)–C(3) N(1)–C(7) C(7)–C(8) N(1)–C(2) C(8)–N(9)

a,b

re [Å] 1.533(1) 1 1.540(1) 1 1.456(1) 1 1.520(1) 1 1.452(1) 1 1.537(1) 1 1.365(2) 2 1.360(2)2

N

NH2

638

8 Molecules with Six Carbon Atoms

C(2)=O(6) C(8)=O(10) C–H N(9)–H(1) N(9)–H(2)

1.229(1) 3 1.221(1)3 1.094 c 1.016 c 1.009 c

Bond angles C(2)–N(1)–C(5) N(1)–C(2)–C(3) N(1)–C(7)–C(8) C(7)–C(8)–N(9) N(1)–C(2)=O(6) C(2)–N(1)–C(7) C(7)–C(8)=O(10)

θe [deg] a,b

Dihedral angles C(3)–C(2)–N(1)–C(5) C(2)–C(3)…C(5)–C(4) C(5)–N(1)–C(2)=O(6) C(3)–C(2)–N(1)–C(7) C(2)–N(1)–C(7)–C(8) N(1)–C(7)–C(8)–N(9) N(1)–C(7)–C(8)=O(10)

τe [deg] a,b

113.4(6) 4 106.9(6) 4 111.9(6) 4 112.5(6) 4 123.0(4) 5 120.4(4) 5 120.2(4) 5

1.3 c 154.1 c 170(6) 6 177(6) 6 84.2 c -68.7 c 111.9 c

Copyright 2010 with permission from Elsevier .

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were constrained to the values from B3LYP/6-31G** computation. c Assumed at the value from computation as indicated above. b

According to predictions of B3LYP/6-31G** computations, the title molecules exist as two stable enantiomers, characterized by different values of the C(2)–N(1)–C(7)–C(8) and N(1)–C(7)–C(8)=O(10) dihedral angles, namely, for one enantiomer these angles are close to 90° and 120°, respectively, and for the other one, they are close to 270° and 240°, respectively. These enantiomers are not distinguishable by GED. The GED experiment was carried out at the nozzle temperature of 550 K. Local C2v symmetry was assumed for each of the CH2 groups, all the C−H bond lengths and all the H−C−H bond angles were assumed to be equal. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated using harmonic force constants from B3LYP or MP2 computation (with cc-pVTZ basis set) and cubic force constants from B3LYP/6-31G** computation as well as taking into account non-linear kinematic effects. The molecular conformation was predicted to be stabilized due to formation of the intramolecular hydrogen bond: re[O(6)…H(1)] = 1.9 Å and ∠e[N(9)−H(1)…O(6)] = 143.8°. An envelope form of the pyrrolidine ring is defined by the deviation of the C(4) atom from the ring plane (∠e[C(2)–C(3)–C(5)–C(4)] = 154.1°). The sum of the bond angles around the N(1) atom was found to be 360.0(7)°, i.e. the bond angle configuration around this atom is planar. Ksenafontov DN, Moiseeva NF, Khristenko LV, Karasev NM, Shishkov IF, Vilkov LV (2010) The structure and conformations of piracetam (2-oxo-1-pyrrolidineacetamide): Gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 984 (1-3):89-95

745 CAS RN: 186047-23-4 MGD RN: 383816 GED combined with MS and

(3Z)-4-Hydroxy-3-methyl-3-penten-2-one C6H10O2 Cs

8 Molecules with Six Carbon Atoms

639

augmented by DFT computations

Bonds C(3)=C(4) C(3)–C(2) C(4)–C(5) C(2)–C(1) C(3)–C(6) C(4)–O(1) C(2)=O(2) C(5)–H(2) C(5)–H(3) C(1)–H(5) C(1)–H(6) C(6)–H(8) C(6)–H(9) O(1)–H(1)

rh1 [Å] a,b 1.381(3) 1 1.451(3) 1 1.504(3) 1 1.513(3) 1 1.513(3) 1 1.317(4) 2 1.244(4) 2 1.092(3) 3 1.095(3) 3 1.091(3) 3 1.097(3) 3 1.092(3) 3 1.098(3) 3 1.018(3) 3

Bond angles C(4)=C(3)–C(2) C(3)=C(4)–O(1) C(3)–C(2)=O(2) C(3)=C(4)–C(5) C(3)–C(2)–C(1) C(2)–C(3)–C(6) C(4)=C(3)–C(6) H(2)–C(5)–C(4) H(3)–C(5)–C(4) H(5)–C(1)–C(2) H(6)–C(1)–C(2) H(8)–C(6)–C(3) H(9)–C(6)–C(3) H(3)–C(5)–H(4) H(6)–C(1)–H(5) H(9)–C(6)–H(10) H(1)–O(1)–C(4)

θh1 [deg] b,c

Dihedral angles H(8)–C(6)–C(3)=C(4) H(5)–C(1)–C(2)=O(2) H(2)–C(5)–C(4)–O(1)

τh1 [deg]

O

OH

H 3C

CH3 CH3

117.2(8) 122.2(10) 122.4(10) 123.1(32) 118.7(30) 119.1(22) 122.9(20) 108.4(14) 4 110.5(15) 4 108.5(13) 5 110.1(13) 5 108.7(11) 6 111.4(13) 6 109.2(22) 109.1(20) 111.9(30) 105.8 d

0.0 d 0.0 d 0.0 d

Copyright 2012 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group. Differences between parameters in each group were fixed at the values from B3LYP/aug-cc-pVTZ computation. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Assumed at the value from computation as above. Only enol tautomer of 3-methyl-2,4-pentanedione (100(3)%) was found to be present in the gas phase (Teffusion cell = 274(7) K). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/aug-cc-pVTZ computation.

640

8 Molecules with Six Carbon Atoms

Belova NV, Girichev GV, Oberhammer H, Trang NH, Shlykov SA (2012) Tautomeric properties and gas-phase structure of 3-methyl-2,4-pentanedione. J Mol Struct 1023:49-54

746 CAS RN: 502-44-3 MGD RN: 796703 MW augmented by ab initio calculations

2-Oxepanone ε-Caprolactone C6H10O2 C1 (chair) O O

Bonds O(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(7) C(7)–O(1) C(2)=O(8)

r0 [Å] 1.360 b 1.517 b 1.540 b 1.529 b 1.529 b 1.525 b 1.432 c 1.210 b

rs [Å] a 1.333(22) 1.538(29) 1.523(10) 1.535(10) 1.525(15) 1.530(8) 1.429(14)

Bond angles O(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(7) C(6)–C(7)–O(1) C(7)–O(1)–C(2) C(3)–C(2)=O(8)

θ0 [deg]a

θs [deg]a

Dihedral angles O(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–C(7) C(5)–C(6)–C(7)–O(1) C(6)–C(7)–O(1)–C(2) C(7)–O(1)–C(2)–C(3) C(4)–C(3)–C(2)=O(8)

τ0 [deg]a

τs [deg]a

119.08(55) 113.87(25) 113.62(32) 114.45(41) 115.17(59) 113.40(80) c 121.41(65) c 122.80(28)

-64.4(19) 81.55(53) -59.05(13) 57.47(15) -81.8(13) c 70.9(10) c -2.2(16) c 111.38(74)

119.1(15) 113.5(14) 113.2(15) 114.0(12) 113.9(15) 113.2(11) 121.5(19) 121.27(90)

-65.5(44) 81.1(47) -60.6(10) 59.8(35) -83.1(32) 71.9(44) 4.6(28)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Fixed to the value from MP2/6-311++G(d,p) calculations. c Dependent parameter. b

The rotational spectrum of ε-caprolactone was recorded by two different supersonic-jet FTMW spectrometers in the frequency range between 6 and 18 GHz. According to predictions of CCSD(T)/aug-cc-pVTZ calculations, the chair conformer is the most stable one in the pseudorotating molecule; the next low-energy conformer, twist-boat, is higher in energy than the global minimum by 9.4 kJ mol-1. Both conformers were detected in the experimental spectrum. The r0 and rs structures of the heavy-atom skeleton were determined for the most stable conformer from the ground-state rotational constants of eight isotopic species (main, six 13C and 18O).

8 Molecules with Six Carbon Atoms

641

Jahn MK, Dewald DA, Vallejo-López M, Cocinero EJ, Lesarri A, Zou W, Cremer D, Grabow JU (2014) Pseudorotational landscape of seven-membered rings: the most stable chair and twist-boat conformers of εcaprolactone. Chem Eur J 20(43):14084-14089 747 CAS RN: 674-26-0 MGD RN: 544733 MW supported by QC calculations

Bonds C(1)–C(2) C(2)–C(3) C(5)–C(6) C(1)–C(6) C(1)–C(7)

Tetrahydro-4-hydroxy-4-methyl-2H-pyran-2-one Mevalonolactone C6H10O3 C1 O

r0 [Å] a 1.531(3) 1.496(5) 1.534(6) 1.506(6) 1.534(3)

Dihedral angles τ0 [deg] a C(5)–C(6)–C(1)–C(2) 46.32(14) C(6)–C(1)–C(2)–C(3) -59.08(21)

rs [Å] a 1.505(22) 1.499(87) 1.576(11) 1.503(17) 1.551(21)

O

OH CH3

τs [deg] a 49.6(34) -60.6(77)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of mevalonolactone were recorded in a supersonic beam by a pulsed-jet chirped-pulse FTMW spectrometer in the frequency region between 2 and 12 GHz. Two conformers were observed. The partial r0 and rs structures of the most stable conformer were determined for the carbon skeleton using the ground-state rotational constants of seven isotopic species (main and six 13C). Domingos SR, Pérez C, Schnell M (2017) On the structural intricacies of a metabolic precursor: Direct spectroscopic detection of water-induced conformational reshaping of mevalonolactone. J Chem Phys 147(12):124310/1-124310/6 https://doi.org/10.1063/1.4997162

748 CAS RN: 108-85-0 MGD RN: 992310 MW augmented by QC calculations

Bromocyclohexane Cyclohexyl bromide C6H11Br Cs (axial) Cs (equatorial) Br

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–Br C(2)–H(4) C(2)–H(5) C(3)–H(6) C(3)–H(7)

axial r0 [Å] a 1.532(3) 1.531(3) 1.526(3) 1.975(5) 1.096(2) 1.095(2) 1.100(2) 1.094(2)

equatorial r0 [Å] a 1.532(3) 1.539(3) 1.524(3) 1.966(5) 1.098(2) 1.095(2) 1.097(2) 1.094(2)

642

8 Molecules with Six Carbon Atoms

C(4)–H(1) C(1)–H(2) C(1)–H(3)

1.092(2) 1.099(2) 1.095(2)

1.095(2) 1.098(2) 1.095(2)

Bond angles C(1)–C(2)–C(3) C(4)–C(3)–C(2) C(2)–C(1)–C(6) C(3)–C(4)–C(5) H(2)–C(1)–H(3) H(1)–C(4)–Br H(2)–C(1)–C(2) H(3)–C(1)–C(2) C(1)–C(2)–H(4) C(1)–C(2)–H(5) H(1)–C(4)–C(3) Br–C(4)–C(3) H(4)–C(2)–C(3) H(5)–C(2)–C(3) C(4)–C(3)–H(6) C(2)–C(3)–H(6) C(4)–C(3)–H(7) C(2)–C(3)–H(7) H(4)–C(2)–H(5) H(6)–C(3)–H(7)

θ0 [deg] a

θ0 [deg] a

Dihedral angles C(6)–C(1)–C(2)–C(3) C(5)–C(4)–C(3)–C(2)

θ0 [deg] a

θ0 [deg] a

111.2(5) 112.6(5) 111.4(5) 112.0(5) 106.9(5) 103.7(5) 109.0(5) 110.2(5) 109.5(5) 110.4(5) 110.4(5) 110.0(5) 109.2(5) 109.5(5) 106.5(5) 109.0(5) 110.1(5) 111.1(5) 107.0(5) 107.3(5)

55.3(10) 51.8(10)

111.3(5) 109.4(5) 110.9(5) 112.5(5) 107.0(5) 104.5(5) 109.1(5) 110.3(5) 109.3(5) 110.6(5) 110.2(5) 109.6(5) 109.3(5) 109.4(5) 108.8(5) 109.9(5) 110.1(5) 111.0(5) 106.9(5) 107.4(5)

55.9(10) 57.7(10)

Copyright 2008 with permission from Elsevier. a

Parenthesized estimated uncertainties in units of the last significant digit.

axial

equatorial

The chair-axial and chair-equatorial conformers were identified in the temperature-dependent IR vibrational spectra. The percentage of the axial conformer was estimated to be 24(2) % at ambient temperature. The r0 structural parameters of the axial and equatorial conformers were obtained by adjusting the MP2_full/6311+G(d,p) structures to the previously published experimental ground-state rotational constants of two isotopic species (main and 81Br). Durig JR, El Defrawy AM, Ward RM, Guirgis GA, Gounev TK (2009) Conformational stability of bromocyclohexane from temperature dependent FT-IR spectra of xenon solutions, r0 structural parameters and vibrational assignment. J Mol Struct 918(1-3):26-38

8 Molecules with Six Carbon Atoms

643

Chlorocyclohexane Cyclohexyl chloride C6H11Cl Cs (axial) Cs (equatorial)

749 CAS RN: 542-18-7 MGD RN: 894493 MW augmented by ab initio calculations

C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–Cl C(2)–H(3) C(2)–H(4) C(3)–H(5) C(3)–H(6) C(4)–H(7) C(1)–H(2) C(1)–H(1)

r0 [Å]a axial 1.532(3) 1.529(3) 1.528(3) 1.807(5) 1.096(2) 1.095(2) 1.099(2) 1.094(2) 1.092(2) 1.099(2) 1.095(2)

Bond angles

θ0 [deg]a

Bonds

C(1)–C(2)–C(3) C(4)–C(3)–C(2) C(2)–C(1)–C(6) C(3)–C(4)–C(5) H(2)–C(1)–H(1) H(7)–C(4)–Cl H(2)–C(1)–C(2) H(1)–C(1)–C(2) C(1)–C(2)–H(3) C(1)–C(2)–H(4) H(7)–C(4)–C(3) Cl–C(4)–C(3) H(3)–C(2)–C(3) H(4)–C(2)–C(3) C(4)–C(3)–H(5) C(2)–C(3)–H(5) C(4)–C(3)–H(6) C(2)–C(3)–H(6) H(3)–C(2)–H(4) H(5)–C(3)–H(6) Dihedral angles C(6)–C(1)–C(2)–C(3) C(5)–C(4)–C(3)–C(2)

Cl

equatorial 1.532(3) 1.536(3) 1.524(3) 1.802(5) 1.098(2) 1.095(2) 1.097(2) 1.094(2) 1.095(2) 1.098(2) 1.095(2)

axial 111.1(5) 112.2(5) 111.6(5) 111.6(5) 106.9(5) 104.7(5) 109.3(5) 110.4(5) 109.4(5) 110.4(5) 109.7(5) 110.5(5) 109.4(5) 109.4(5) 107.0(5) 109.5(5) 109.7(5) 111.0(5) 107.0(5) 107.4(5)

equatorial 111.3(5) 109.7(5) 110.6(5) 112.6(5) 107.0(5) 104.8(5) 109.3(5) 110.2(5) 109.2(5) 110.6(5) 109.7(5) 110.1(5) 109.3(5) 109.7(5) 108.6(5) 109.8(5) 109.9(5) 110.9(5) 106.8(5) 107.3(5)

τ0 [deg]a axial 55.1(10) 53.5(10)

equatorial 56.3(10) 56.7(10)

axial

Reproduced with permission of SNCSC

a

Parenthesized estimated uncertainties in units of the last significant digit.

equatorial

The equatorial and axial conformers were identified in the temperature-dependent IR vibrational spectra. The percentage of the axial conformer was estimated to be 34(1) % for ambient temperature.

644

8 Molecules with Six Carbon Atoms

The r0 structural parameters of each conformer were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of two isotopic species. Durig JR, El Defrawy AM, Ward RM, Guirgis GA, Gounev TK (2008) Conformational stability of chlorocyclohexane from temperature-dependent FT-IR spectra of xenon solutions, r0 structural parameters, and vibrational assignment. Struct Chem 19(4):579-594

750 CAS RN: 372-46-3 MGD RN: 128701 MW augmented by ab initio calculations

Fluorocyclohexane Cyclohexyl fluoride C6H11F Cs (axial) Cs (equatorial) F

equatorial r see [Å] a 1.51218(43) 1.53121(71) 1.52554(25) 1.39260(62) 1.0942(15) 1.0893(24) 1.0934(15) 1.0892(22) 1.0946(13) 1.0905(17) 1.0941(15)

axial r see [Å] a 1.51423(94) 1.5257(13) 1.52690(71) 1.4036(13) 1.0908(25) 1.0901(27) 1.0938(32) 1.0902(24) 1.0921(38) 1.0905(46) 1.0949(39)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–C(6) C(2)–C(1)–F H(a)–C(1)–F C(1)–C(2)–H(q) C(1)–C(2)–H(a) C(2)–C(3)–H(q) C(2)–C(3)–H(a) C(3)–C(4)–H(q) C(3)–C(4)–H(a) H(a)–C(2)–H(q) H(a)–C(3)–H(q) H(a)–C(4)–H(q)

θ see [deg] a

θ see [deg] a

Dihedral angles C(1)–C(2)–C(3)–C(4) F–C(1)–C(2)–C(3) F–C(1)–C(2)–H(q) F–C(1)–C(2)–H(a) C(1)–C(2)–C(3)–H(q) C(1)–C(2)–C(3)–H(a) C(2)–C(3)–C(4)–H(q) C(2)–C(3)–C(4)–H(a)

τ see [deg] a

τ see [deg] a

Bond C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–F C(1)–H(a) C(2)–H(q) C(2)–H(a) C(3)–H(q) C(3)–H(a) C(4)–H(q) C(4)–H(a)

110.168(32) 111.007(21) 110.982(22) 112.007(36) 109.084(30) 106.51(15) 109.50(15) 108.01(20) 109.84(15) 109.03(25) 110.246(74) 109.121(75) 107.53(28) 107.07(23) 107.03(21)

55.990(51) -178.154(37) 59.05(19) -57.77(30) 178.57(16) -64.40(14) -178.20(14) 64.53(13)

111.605(57) 110.942(77) 110.618(53) 112.729(76) 110.667(80) 106.14(14) 109.04(17) 107.56(22) 109.72(20) 108.77(34) 110.27(14) 109.30(13) 107.21(32) 107.27(34) 107.00(33)

54.72(10) -177.53(13) 59.28(28) -56.66(34) 177.15(20) -65.79(18) -179.12(24) 63.52(21)

8 Molecules with Six Carbon Atoms

645

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

equatorial

axial

The rotational spectra of fluorocyclohexane were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 20 GHz. The equatorial and axial conformer were observed. The semiexperimental equilibrium structure r see of each of two conformers was determined from the ground-state rotational constants of five isotopic species (main and four 13C) applying rovibrational corrections calculated from the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Juanes M, Vogt N, Demaison J, Leon I, Lesarri A, Rudolph HD (2017) Axial-equatorial isomerism and semiexperimental equilibrium structures of fluorocyclohexane. Phys Chem Chem Phys 19(43):29162-29169

751 CAS RN: 1445-73-4 MGD RN: 213840 MW augmented by ab initio calculations

1-Methyl-4-piperidinone 1-Methyl-4-piperidone C6H11NO Cs O

Bonds C(7)–N N–C(1) C(1)–C(2) C(2)–C(3) C(3)=O

r0 [Å] a 1.452(4) 1.471(2) 1.537(2) 1.508(17) 1.224(10)

rs [Å] a 1.457(4) 1.454(8) 1.521(8) 1.510(7) 1.228(9)

Bond angles C(7)–N–C(1) N–C(1)–C(2) C(5)–N–C(1) C(1)–C(2)–C(3) C(2)–C(3)=O C(2)–C(3)–C(4)

θ0 [deg] a

θs [deg] a

Dihedral angles C(7)–N–C(1)–C(2) N–C(1)–C(2)–C(3) C(1)–C(2)–C(3)–C(4) C(1)–C(2)–C(3)=O

τ0 [deg] a

110.8(2) 110.1(2) 109.6(6) 111.2(5) 122.4(18) 115.1(8)

173.2(7) 53.9(9) -45.6(13) 131.8(15)

110.9(7) 111.2(7) 110.8(7) 111.5(7) 122.6(5) 114.7(7)

τs [deg] a

174.5(7) 52(2) -44.5(16) 132.2(10)

Reprinted with permission. Copyright 2011 American Chemical Society [a]. a

Parenthesized uncertainties in units of the last significant digit.

N

CH3

646

8 Molecules with Six Carbon Atoms

The rotational spectrum of 1-methyl-4-piperidinone was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 9 and 26 GHz. The axial and equatorial conformers were detected. The partial r0 structure of the equatorial conformer was determined from the ground-state rotational constants of seven isotopic species (main, 15N, four 13C and 18O); the structural parameters involving H were assumed at the values from MP2/6-311++G(d,p) calculations. The rs structure was obtained for the heavy-atom skeleton. a. Evangelisti L, Lesarri A, Jahn MK, Cocinero EJ, Caminati W, Grabow JU (2011) N-Methyl inversion and structure of six-membered heterocyclic rings: Rotational spectrum of 1-methyl-4-piperidone. J Phys Chem A 115(34):9545-9551 MW augmented by QC calculations

Bonds C(7)–N N–C(1) C(1)–C(2) C(2)–C(3) C(3)=O C(1)–H(6) C(1)–H(7) C(2)–H(4) C(2)–H(5) C(7)–H(1) C(7)–H(3)

r see [Å] a 1.4521(7) 1.4556(6) 1.5270(10) 1.5097(5) 1.2113(8) 1.0904(9) 1.1046(9) 1.0883(9) 1.0925(9) 1.0887(9) 1.1009(9)

Bond angles N–C(7)–H(3) N–C(7)–H(1) C(1)–N–C(7) C(1)–C(2)–C(3) N–C(1)–C(2) O=C(3)–C(2) C(1)–N–C(5) C(2)–C(3)–C(4) N–C(1)–H(6) C(2)–C(1)–H(6) N–C(1)–H(7) C(2)–C(1)–H(7) H(6)–C(1)–H(7) C(1)–C(2)–H(5) C(3)–C(2)–H(5) C(1)–C(2)–H(4) C(3)–C(2)–H(4) H(4)–C(2)–H(5)

θ see [deg] a

Dihedral angles

τ see [deg] a

H(1)–N–C(7)–H(3) C(1)–N–C(7)–H(3) O=C(3)–C(2)–C(1) C(7)–N–C(1)–C(2) N–C(1)–C(2)–C(3) C(7)–N–C(1)–H(6)

112.29(13) 109.62(13) 110.32(4) 110.57(4) 110.78(4) 122.91(4) 110.03(7) 114.37(4) 108.71(13) 109.88(14) 111.01(15) 109.15(22) 107.25(20) 108.33(9) 107.41(14) 111.65(13) 109.62(13) 109.15(17)

-120.5(2) -119.11(4) 132.03(11) 174.84(5) 54.45(7) 54.01(16)

8 Molecules with Six Carbon Atoms

C(3)–C(2)–C(1)–H(6) C(7)–N–C(1)–H(7) C(3)–C(2)–C(1)–H(7) N–C(1)–C(2)–H(5) O=C(3)–C(2)–H(5) N–C(1)–C(2)–H(4) O=C(3)–C(2)–H(4)

647

174.58(17) -63.73(21) -68.17(14) -63.00(14) -109.96(17) 176.79(13) 8.51(20)

Reprinted with permission. Copyright 2012 American Chemical Society [b].

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see was determined from the previously published experimental ground-state rotational constants of the parent and all mono-substituted heavy-atom species by taking into account rovibrational corrections calculated with the B3LYP/cc-pVTZ harmonic and anharmonic (cubic) force fields. b. Demaison J, Craig NC, Cocinero EJ, Grabow JU, Lesarri A, Rudolph HD (2012) Semiexperimental equilibrium structures for the equatorial conformers of N-methylpiperidone and tropinone by the mixed estimation method. J Phys Chem A 116(34):8684-8692

752 CAS RN: 79265-30-8 MGD RN: 362894 GED augmented by QC computations

2-(Trimethylsilyl)thiazole

N

C6H11NSSi Cs CH3

Bonds Si–C(m) b Si–C(2) C–H C(2)=N(3) C(2)–S N(3)–C(4) C(4)=C(5) C(5)–S

rh1 [Å] a 1.855(2) 1.883(5) 1.108(3) c 1.345(6) 1.718(5) 1.370(5) 1.387(6) 1.700(5)

Bond angles Si–C(2)=N(3) Si–C(2)–S C(2)=N(3)–C(4) N(3)=C(2)–S N(3)–C(4)=C(5) C(4)=C(5)–S C(5)–S–C(2) C(5)=C(4)–H S–C(5)–H C(2)–Si–C(6) C(2)–Si–C(7) Si–C–H H–C–H C(m)–Si–C(m) b

θh1 [deg] a 120.4(4) 125.4(4) 110.0(4) 114.3(4) 115.4(4) 110.0(2) 90.3(2) 124.8(2) 121.9(1) 111.8(7) 107.1(7) 112.1(4) 106.7(4) c 110.3(5) c

S

Si CH3

CH3

648

Dihedral angles N(3)=C(2)–Si–C(6) N(3)=C(2)–Si–C(7) C(2)–Si–C(7)–H(3) C(2)–Si–C(7)–H(4) C(2)–Si–C(7)–H(5) C(2)–Si–C(6)–H(1) C(2)–Si–C(6)–H(2)

8 Molecules with Six Carbon Atoms

τ h1 [deg] a 180.0(2) 59.2(3) -57.2(7) 62.8(7) 177.2(7) 60.0(3) 180.0(3)

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit were not identified, they are presumably the estimated standard deviations. b C(m) is carbon atom of the methyl group. c Restrained to the value from MP2/6-311++G** computation. The GED experiment was carried out at Tnozzle = 293 K. The overall Cs symmetry of the title molecule was assumed in the GED analysis following to prediction of ab initio computations. The silyl group and each of the methyl groups were assumed to have local C3v symmetry. Vibrational corrections to the experimental internuclear distances, ∆rh1= ra − rh1, were calculated using harmonic force field from QC computation. Foerster T, Wann DA, Robertson HE, Rankin DWH (2009) Why are trimethylsilyl groups asymmetrically coordinated? Gas-phase molecular structures of 1-trimetylsilyl-1,2,3-benzotriazole and 2-trimethylsilyl-1,3thiazole. Dalton Trans 16:3026-3033

753 CAS RN: 1445078-83-0 MGD RN: 505640 GED augmented by QC computations

Silacylohexane-1-carbonitrile 1-Cyano-1-silacyclohexane C6H11NSi Cs (axial) Cs (equatorial)

Bonds Si–C(7) Si–C(2) C(2)–C(3) C(3)–C(4) C–H Si–H C≡N

ra [Å] a,b 1.875(2) 1 1.866(2) 1 1.541(3) 2 1.533(3) 2 1.083(4) c 1.475 d 1.161(5)

Bond angles C(2)–Si–C(6) C(3)–C4)–C(5) H–C–H C(2)–C(3)–C(4) Si–C(2)–C(3) C(7)–Si–C(2)

θh1 [deg] a

Dihedral angles C(2)–Si–C(6)–C(5) Si–C(6)–C(5)–C(4) C(6)–C(5)–C(4)–C(3)

τh1 [deg] a

108.2(13) 113.5(16) 106.7 c,d 114.8(9) e 110.5(5) e 106.8(14) e

-37.9(39) e 51.8(17) e -66.1(15) e

SiH

C

N

axial

8 Molecules with Six Carbon Atoms

649

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from M06-2X/aug-cc-pVTZ computation. c Assumed at the value from computation as above. d Average value. e Dependent parameter. b

The GED experiment was carried out at Teffusion cell = 279(3) K. The title compound was found to exist as a mixture of the axial (84(12)%) and equatorial (16(12)%) conformers possessing a chair conformation of the ring and differing in the positions of the substituent. The corresponding ΔG value of 1.0(4) kcal mol−1 agrees well with the CCSD(T)/CBS prediction of 0.72 kcal mol−1. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X/aug-cc-pVTZ computation. The structural parameters were presented for the axial conformer. Belyakov AV, Sigolaev YF, Shlykov SA, Wallevik SÓ, Jonsdottir NR, Jonsdottir S, Kvaran Á, Bjornsson R, Arnason I (2017) Conformational properties of 1-cyano-1-silacyclohexane, C5H10SiHCN: Gas electron diffraction, low-temperature NMR and quantum chemical calculations. J Mol Struct 1132:149-156

754 CAS RN: 110-82-7 MGD RN: 821476 MW augmented by QC calculations

Bonds C–C C–H(1) b C–H(2) c

r0 [Å]a 1.536(3) 1.098(1) 1.095(1)

Bond angles C–C–H(1) b C–C–H(2) c C–C–C H–C–H

θ0 [deg] a

Cyclohexane C6H12 D3d

108.8(2) 110.2(2) 111.1(2) 107.6(2)

Copyright © 2008 John Wiley & Sons, Ltd. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Axial H. c Equatorial H. b

The r0 structure of the most stable chair conformer was determined by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of five isotopic species. Durig JR, Zheng C, El Defrawy AM, Ward RM, Gounev TK, Ravindranath K, Rao NR (2009) On the relative intensities of the Raman active fundamentals, r0 structural parameters, and pathway of chair-boat interconversion of cyclohexane and cyclohexane-d12. J Raman Spectrosc 40(2):197-204

650

8 Molecules with Six Carbon Atoms

755 CAS RN: 26702-69-2 MGD RN: 358868 IR

Distance Rcm b

Ethene trimer Ethylene trimer C6H12 C3 or C3h

r0 [Å] a 3.947

H

H

H

H

3

Reproduced with permission from the PCCP Owner Societies.

a b

Uncertainty was not given in the original paper. Intermolecular separation.

The rotationally resolved IR spectrum of the perdeuterated ethylene trimer was recorded in a supersonic jet by a tunable quantum cascade laser spectrometer in the region of ν11 fundamental band region of C2D4 at about 2200 cm-1. The partial r0 structure was determined from the resulting ground-state rotational constants under the assumption that the structural parameters of the monomer subunit were not changed upon complexation. The trimer forms a barrel-shaped structure with C3h or C3 symmetry, in which the C-C figure axis of the ethylene subunits are approximately aligned along the trimer axis. Rezaei M, Michaelian KH, McKellar ARW, Moazzen-Ahmadi N (2012) Infrared spectra of ethylene clusters: (C2D4)2 and (C2D4)3. Phys Chem Chem Phys 14(23):8415-8418

756 CAS RN: 286011-03-8 MGD RN: 317118 GED augmented by ab initio computations

1,1,2,2-Tetramethyl-1,2-bis(trifluoromethyl)disilane C6H12F6Si2 C2 F

F H 3C

CH3 Si

a

Bonds Si–C Si–Si C–H C–F Si(1)–C(6) Si(1)–C(8) Si(1)–C(7)

rh1 [Å] 1.9019(7) b 2.364(4) 1.096(2) 1.3557(4) 1.8681(8) c 1.8681(8) c 1.936(2) c

Bond angles Si–C–H Si–C–F C–Si–C Si–Si–C d Si–Si–C e Si(2)–Si(1)–C(6) Si(2)–Si(1)–C(8)

θh1 [deg] a

111.3(7) b 112.84(6) b 106.1(2) 104.6(3) 112.3(3) 111.5(3) f 113.1(3) f

F

F

Si H3C

CH3 F

F

8 Molecules with Six Carbon Atoms

Si(2)–Si(1)–C(7)

104.6(3) g

Dihedral angle C(7)–Si(1)–Si(2)–C(4)

τh1 [deg] a

651

171.5(31)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Uncertainties given in parentheses in the last digits are the standard deviations. Average value. c Difference between the Si–C(H3) and Si–C(F3) bond lengths was restrained to the value from MP2/6311++G** computation. d C atom in the CF3 group. e C atom in the CH3 group. f Difference between the Si–Si–C(H3) bond angles was restrained to the value from computation at the level of theory as indicated above. g Dependent parameter. b

MP2 computations with various basis sets predicted different number of minima on the PEF calculated as a function of the C(16)–Si(1)–Si(2)–C(7) torsion angle. However, MP2/aug-cc-pVDZ calculation verified only one real minimum corresponding to the structure with the antiperiplanar C(7)–Si(1)–Si(2)–C(4) torsional angle (C2 point-group symmetry). The GED analysis (Tnozzle = 293 K) was carried out for the model of a single conformer with C2 symmetry. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from MP2/6-31G* computation. Masters SL, Robertson HE, Wann DA, Hölbling M, Hassler K, Bjornsson R, Wallevik SÓ, Arnason I (2015) Molecular structure of 1,2-bis(trifluoromethyl)-1,1,2,2-tetramethyldisilane in the gas, liquid, and solid phases: Unusual conformational changes between phases. J Phys Chem A 119 (9):1600-1608

757 CAS RN: 104518-71-0 MGD RN: 468547 GED augmented by QC computations

Bonds N(1)–N(5) N(1)–C(2) N(1)–C(6) C(2)–C(3) C(3)–C(7) C(3)–C(8) C–H Bond angles N(1)–C(6)–N(5) C(6)–N(1)–N(5) N(5)–N(1)–C(2) N(1)–C(2)–C(3)

3,3-Dimethyl-1,5-diazabicyclo[3.1.0]hexane C6H12N2 Cs (chair) Cs (boat)

r see [Å] a,b chair boat 1.545(7) 1 1.512(7) 1 1 1.475(7) 1.468(7) 1 1 1.443(7) 1.444(7) 1 1 1.527(7) 1.541(7) 1 1 1.516(7) 1.526(7) 1 1 1.523(7) 1.525(7) 1 2,c 1.091(6) 1.091(6) 2,c

θ see [deg] a,b

chair 64.7 d 57.6 d 105.8(9) 3 106.0(22) e

boat 63.2 d 58.4 d 107.6(9) 3 109.8(24) e

N

CH3

N

CH3

652

8 Molecules with Six Carbon Atoms

C(2)–C(3)–C(4) C(2)–C(3)–C(7) C(2)–C(3)–C(8) N(1)–C(2)–H C(3)–C(2)–H N(1)–C(6)–H

100.4(24) e 112.8(10) 4 109.5(10) 4 109.8(8) 5,c 111.2(8) 5,c 116.7(8) 5,c

Dihedral angles

τ see [deg] a,b

chair 107.2(17) 6 218.2(20)

ϕ1 f ϕ2 g

102.3(28) e 113.2(10) 4 109.9(10) 4 107.7(8) 5,c 111.2(8) 5,c 116.9(8) 5,c

boat 106.3(17) 6 164.3(33)

Reprinted with permission. Copyright 2015 American Chemical Society.

chair

boat

a

Parenthesized uncertainties in units of the last significant digit are total errors estimated by a new approach based on the Monte Carlo method. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/cc-pVTZ computation. c Average value. d Fixed due to constrained refinement of the N–N and N–C(6) bond lengths in one group with fixed difference between them. e Dependent parameter. f Dihedral angle between the NC(6)N and C(2)NNC(4) planes. g Dihedral angle between the C(2)C(3)C(4) and C(2)NNC(4) planes. MP2/cc-pVTZ computations predicted two conformers with the chair and boat conformations of the two-ring fragments. In the GED study (Tnozzle= 330 K), the ratio of these conformers was determined to be chair : boat = 68(8) : 32(8) (in %). Possible existence of the twisted conformation (the N(1), N(5), C(6) and C(3) atoms are in one plane, whereas the C(2) and C(4) atoms are below and above this plane, respectively) was checked and excluded. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated with quadratic and cubic force constants from QC computations by taking into account non-linear kinematic effects. Vishnevskiy YV, Schwabedissen J, Rykov AN, Kuznetsov VV, Makhova NN (2015) Conformational and bonding properties of 3,3-dimethyl- and 6,6-dimethyl-1,5-diazabicyclo[3.1.0]hexane: A case study employing the Monte Carlo method in gas electron diffraction. J Phys Chem A 119 (44):10871-10881

758 CAS RN: 104518-69-6 MGD RN: 468351 GED augmented by QC computations

6,6-Dimethyl-1,5-diazabicyclo[3.1.0]hexane C6H12N2 Cs

8 Molecules with Six Carbon Atoms

Bonds N(1)–N(5) N(1)–C(2) N(1)–C(6) C(2)–C(3) C(6)–C(7) C(6)–C(8) C–H

r see [Å] a,b 1.522(7) 1 1.472(7) 1 1.455(7) 1 1.538(7) 1 1.506(7) 1 1.505(7) 1 1.095(6) c

Bond angles N(1)–C(6)–N(5) C(6)–N(1)–N(5) N(5)–N(1)–C(2) N(1)–C(2)–C(3) C(2)–C(3)–C(4) N(1)–C(6)–C(7) N(1)–C(6)–C(8) N(1)–C(2)–H C(3)–C(2)–H C(2)–C(3)–H

θ see [deg] a,b

Dihedral angles

τ see [deg] a

ϕ1 f ϕ2 g

653

H 3C

H 3C

N N

63.1 d 58.5 d 108.2(7) 109.3(18) e 105.1(20) e 122.4(14) 2 112.4(14) 2 108.3(7) 3,c 112.5(7) 3,c 112.1(7) 3,c

108.0(12) 178.8(30)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are total errors estimated by a new approach based on the Monte Carlo method. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/cc-pVTZ computation. c Average value. d Fixed due to constrained refinement of the N–N and N–C(6) bond lengths in one group with fixed difference between them. e Dependent parameter. f Dihedral angle between the NC(6)N and C(2)NNC(4) planes. g Dihedral angle between the C(2)C(3)C(4) and C(2)NNC(4) planes. Only one conformer with large amplitude motion along the coordinate ϕ2 was predicted by computations at the MP2/cc-pVTZ level of theory. According to results of the GED analysis (Tnozzle= 323 K), the title compound exists as a single conformer. Possible existence of a twisted conformation (atoms N(1), N(5), C(6) and C(3) are in one plane, whereas the atoms C(2) and C(4) are below and above this plane, respectively) was checked and excluded within experimental uncertainties. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated with quadratic and cubic force constants from QC computations by taking into account non-linear kinematic effects. Vishnevskiy YV, Schwabedissen J, Rykov AN, Kuznetsov VV, Makhova NN (2015) Conformational and bonding properties of 3,3-dimethyl- and 6,6-dimethyl-1,5-diazabicyclo[3.1.0]hexane: A case study employing the Monte Carlo method in gas electron diffraction. J Phys Chem A 119 (44):10871-10881

759 CAS RN: 100-97-0

1,3,5,7-Tetraazatricyclo[3.3.1.13,7]decane Hexamethylenetetramine

654

8 Molecules with Six Carbon Atoms

MGD RN: 300996 GED augmented by ab initio computations

Urotropine C6H12N4 Td

Bonds C–H C–N

re [Å] a 1.081(5) 1.466(1)

Bond angles H–C(1)–H N(1)–C(1)–N(2) N(2)–C(1)–H(1) C(1)–N(2)–C(3)

θe [deg] a

Dihedral angles N(1)–C(1)–N(2)–C(3) H(1)–C(1)–N(2)–C(3) H(1)–C(1)–N(2)–C(2)

τe [deg] a

ra [Å] 1.1016 1.4758

109.8(11) 113.0(1) 108.4(3) 107.7(1)

57.9(1) -62.3(7) -178.2(7)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last digits were not specified, probably estimated total errors.

The GED experiment was carried out at Tnozzle = 353 K. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2_full/cc-pVTZ quadratic and cubic force constants by taking into account non-linear kinematic effects. Khaikin LS, Grikina OE, Karasev NM, Kovtun DM, Kochikov IV (2014) Electron diffraction study of the equilibrium structure of hexamethylenetetramine involving data from quantum chemistry and vibrational spectroscopy. Russ J Phys Chem A / Zh Fiz Khim 88 / 88 (4 / 4):652-656 / 638-642

760 CAS RN: 66-25-1 MGD RN: 440298 MW supported by QC calculations

Hexanal

O

H 3C

Bonds O=C(1) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) Bond angles O=C(1)–C(2)

H

aaa-s rs [Å] a 1.2078(51) 1.5112(24) 1.596(12) 1.420(14) 1.5327(42) 1.532(20)

aag-s rs [Å] a 1.2105(55) 1.5032(46) 1.5575(65) 1.4782(68) 1.5436(34) 1.5254(59)

aga-s rs [Å] a

gaa-s rs [Å] a

1.5256(25) 1.6213(55) 1.4847(82) 1.5309(48) 1.5254(45)

1.5246(80) 1.5507(78) 1.4731(81) 1.5401(42) 1.5193(72)

θs [deg] a

θs [deg] a

θs [deg] a

θs [deg] a

124.58(29)

124.81(26)

C6H12O Cs (aaa-s) C1 (aag-s) C1 (aga-s) C1 (gaa-s)

8 Molecules with Six Carbon Atoms

655

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6)

116.80(46) 112.90(61) 111.26(58) 112.8(16)

115.02(22) 112.30(30) 111.78(45) 113.33(40)

113.24(36) 109.81(28) 115.87(26) 112.87(61)

115.51(66) 112.53(88) 112.97(52) 114.06(24)

Dihedral angles O=C(1)–C(2)–C(3) C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6)

τs [deg] a

τs [deg] a

τs [deg] a

τs [deg] a

178.69(31) 66.25(39) 172.08(69)

179.68(67) 177.44(51) 64.90(55)

-3.8(76) 178.2(47) 179.8(38) -179.4(48)

6.62(64) 71.72(50) -178.68(46) -178.74(48)

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

aaa-s

aga-s

aag-s

gaa-s

The rotational spectrum of the title compound was recorded by a broad-band chirped-pulse FTMW spectrometer in the frequency region between 6 and 40 GHz. Rotational transitions were assigned to twelve conformers, described by the synclinal (g) and/or antiperiplanar (a) aliphatic C–C–C–C dihedral angles and by the synperiplanar (s) or synclinal (g) C–C–C=O dihedral angle. The lowest energy conformer is aaa-s; the aag-s, aga_s and gaa-s conformers are higher in energy than the aaa-s by 3, 214 and 203 cm-1, respectively, as predicted by B3LYP-D3/aug-cc-pVTZ calculations. The rotational spectra of the 13C and 18O isotopic species for the two lowest energy conformers, aaa-s and aag-s, and the 13C isotopic species for the third and fourth lowest energy conformers were assigned. The rs structure of the heavy-atom skeleton was determined for each of these conformers. Seifert NA, Finneran IA, Perez C, Zaleski DP, Neill JL, Steber AL, Suenram RD, Lesarri A, Shipman ST, Pate BH (2015) AUTOFIT, an automated fitting tool for broadband rotational spectra, and applications to 1-hexanal. J Mol Spectrosc 312:13-21

761 CAS RN: MGD RN: 414035 MW augmented by ab initio calculations

Cyclobutanone – ethanol (1/1) Cyclobutanone – ethyl alcohol (1/1) C6H12O2 C1 O

H 3C

OH

656

8 Molecules with Six Carbon Atoms

Distances O(12)…O(1) C(2)=O(1) C(2)–C(3) C(2)–C(4) C(3)–C(5) C(3)–H(1) C(3)–H(2) C(4)–H(3) C(4)–H(4) C(5)–H(5) C(5)–H(6) C(13)–O(12) C(13)–C(14) O(12)–H(7) C(13)–H(8) C(13)–H(9) C(14)–H(10) C(14)–H(11) C(14)–H(12)

r0 [Å] a 2.924(1) 1.212 b 1.529 b 1.531 b 1.558 b 1.092 b 1.095 b 1.092 b 1.096 b 1.090 b 1.092 b 1.422 b 1.522 b 0.967 b 1.099 b 1.093 b 1.095 b 1.093 b 1.095 b

Bond angles C(3)–C(2)=O(1) C(4)–C(2)–C(3) C(2)–C(3)–C(5) C(2)–C(3)–H(1) C(2)–C(3)–H(2) C(2)–C(4)–H(3) C(2)–C(4)–H(4) C(3)–C(5)–H(5) C(3)–C(5)–H(6) C(14)–C(13)–O(12) C(13)–O(12)–H(7) H(8)–C(13)–O(12) H(9)–C(13)–O(12) H(10)–C(14)–C(13) H(11)–C(14)–C(13) H(12)–C(14)–C(13) O(12)…O(1)=C(2) C(13)–O(12)…O(1)

θ0 [deg]

Dihedral angles C(13)–O(12)…O(1)=C(2) C(4)–C(2)–C(3)…O(1) C(5)–C(3)–C(2)=O(1) H(1)–C(3)–C(2)=O(1) H(2)–C(3)–C(2)=O(1) H(3)–C(4)–C(2)=O(1) H(4)–C(4)–C(2)=O(1) H(5)–C(5)–C(3)–C(2) H(6)–C(5)–C(3)–C(2) O(12)…O(1)=C(2)…C(5) C(14)–C(13)–O(12)…O(1) H(7)–O(12)–C(13)–C(14) H(8)–C(13)–O(12)–H(7) H(8)–C(13)–O(12)–H(7) H(11)–C(14)–C(13)–O(12) H(10)–C(14)–C(13)–O(12) H(12)–C(14)–C(13)–O(12)

τ0 [deg] a

133.4 b 92.2 b 86.5 b 116.9 b 110.1 b 116.8 b 109.8 b 116.4 b 111.4 b 112.0 b 107.0 b 110.5 b 105.9 b 110.5 b 110.1 b 110.7 b 98.9 b 118.9 b

-172.9(3) -172.7 b 156.7 b 35.1 b -91.0 b -34.3 b 91.1 b 135.6 b -97.4 b -79.2 b 59.6 b 57.8 b -65.2 b 178.3 b -62.0 b 57.6 b 178.0 b

8 Molecules with Six Carbon Atoms

657

Copyright 2014 with permission from Elsevier.

a b

Parenthesized uncertainty in units of the last significant digit. Assumed at the MP2/6-311++G(d,p) value.

The rotational spectrum of the binary complex of cyclobutanone with ethanol was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 7 and 16 GHz. The spectrum was assigned to a single conformer with ethanol acting as the proton donor to the electron lone pair of the carbonyl oxygen of cyclobutanone. The partial r0 structure was determined by fitting the ground-state rotational constants of two isotopic species (main and D); the remaining structural parameters were assumed at the calculated value (see above). Evangelisti L, Velino B, Feng G, Gou Q, Caminati W (2014) Adducts of alcohols with ketones: a rotational study of the molecular complex ethylalcohol-cyclobutanone. J Mol Spectrosc 299:38-42

762 CAS RN: 7660-25-5 MGD RN: 389833 MW augmented by ab initio calculations

ß-D-Fructopyranose Fructose C6H12O6 C1 HO

O OH

Bonds O(1)–H C(1)–O(1) C(2)–C(1) H(2)–C(1) H(1)–C(1) C(2)–O(6) H–O(2) C(3)–C(2) O(3)–C(3) H–O(3) C(3)–H(3) C(3)–C(4) C(4)–O(4) H–O(4) H(4)–C(4) O(2)–C(2) C(6)–O(6) H(7)–C(6) H(6)–C(6) C(5)–C(6) C(5)–O(5) H–O(5) H(5)–C(5) C(4)–C(5)

r0 [Å] a 0.9617(13) 1.4195(13) 1.5244(29) 1.0853(31) 1.0920(30) 1.4125(13) 0.9667(13) 1.5250(30) 1.4191(13) 0.9639(13) 1.0888(13) 1.5212(31) 1.4194(13) 0.9624(13) 1.0950(13) 1.4141(29) 1.4295(31) 1.0866(13) 1.0922(13) 1.5169(31) 1.4152(13) 0.9629(13) 1.0961(13) 1.5347(93) b

rs [Å] a

1.5100(60) b

r see [Å] a 0.96170(57) 1.41922(57) 1.5180(12) 1.0853(13) 1.0918(13) 1.4102(13) 0.96670(57) 1.5206(13) 1.41896(57) 0.96390(57) 1.08880(57) 1.5185(13) 1.41896(57) 0.96240(57) 1.09496(57) 1.41169(57) 1.4263(13) 1.08655(57) 1.09215(57) 1.5136(13) 1.41460(57) 0.96290(57) 1.09611(57) 1.5136(40) b

Bond angles C(1)–O(1)–H C(2)–C(1)–O(1) H(2)–C(1)–O(1) H(1)–C(1)–O(1) O(2)–C(2)–C(1)

θ0 [deg] a

θs [deg] a

θ see [deg] a

106.39(33) 109.74(26) 107.04(28) 111.81(31) 109.89(31)

1.5244(29) 1.0853(31) 1.0920(30) 1.5250(30)

1.5212(31)

1.4141(29) 1.4295(31) 1.5169(31)

106.39(33) 109.74(26)

106.37(14) 109.36(11) 107.21(12) 111.92(13) 109.77(13)

HO OH OH

658

8 Molecules with Six Carbon Atoms

H–O(2)–C(2) C(3)–C(2)–C(1) O(3)–C(3)–C(2) H–O(3)–C(3) H(3)–C(3)–C(2) C(4)–C(3)–C(2) O(4)–C(4)–C(3) H–O(4)–C(4) H(4)–C(4)–C(3) O(6)–C(2)–C(1) C(6)–O(6)–C(2) H(7)–C(6)–O(6) H(6)–C(6)–O(6) C(5)–C(6)–O(6) O(5)–C(5)–C(6) H–O(5)–C(5) H(5)–C(5)–C(6) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(2)–C(1)–H(2) C(2)–C(1)–H(1)

105.84(33) 113.22(39) 111.92(31) 105.94(33) 108.51(33) 111.40(39) 110.75(32) 106.65(33) 108.73(33) 105.51(42) 114.84(27) 105.83(33) 110.17(33) 112.02(35) 109.31(31) 106.04(33) 108.35(33) 110.22(58) 108.49(41) 109.79(35) 109.33(33)

Dihedral angles C(2)–C(1)–O(1)–H H(2)–C(1)–O(1)–H H(1)–C(1)–O(1)–H O(2)–C(2)–C(1)–O(1) H–O(2)–C(2)–C(1) C(3)–C(2)–C(1)–O(1) O(3)–C(3)–C(2)–C(1) H–O(3)–C(3)–C(2) H–O(3)–C(2)–C(1) C(4)–C(3)–C(2)–C(1) O(4)–C(4)–C(3)–C(2) H–O(4)–C(4)–C(3) H(4)–C(4)–C(3)–C(2) O(6)–C(2)–C(1)–O(1) C(6)–O(6)–C(2)–C(1) H(7)–C(6)–O(6)–C(2) H(6)–C(6)–O(6)–C(2) C(5)–C(6)–O(6)–C(2) O(5)–C(5)–C(6)–O(6) H–O(5)–C(5)–C(6) H–O(5)–C(5)–C(6) C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6) C(3)–C(2)–C(1)–H(2) C(3)–C(2)–C(1)–H(1)

τ0 [deg] a

111.0(20)

109.6(13)

b b b b

-65.43(34) 175.48(40) 56.07(40) -52.52(41) 36.42(46) -172.07(33) 64.20(44) 46.88(46) -53.34(46) -171.96(66) 173.69(44) 43.89(46) -64.83(46) 67.70(39) -180.57(34) -177.48(46) 64.54(46) -59.31(52) -67.01(39) 166.14(46) 172.48(46) 54.26(83) b -53.72(77) b -54.68(47) b 64.96(51) b

110.70(50) b 108.60(40) b 112.5(13) b 106.8(15) b

τs [deg] a

-65.43(34) 175.48(40) 56.07(40) -52.52(41) 36.42(46) 64.20(44) 46.88(46) -53.34(46) -171.96(66) 173.69(44) 43.89(46) -64.83(46) 67.70(39) 64.54(46) -59.31(52) -67.01(39) 166.14(46) 172.48(46) 50.0(20) b -52.00(90) b -49.7(10) b 72.8(18) b

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

105.79(14) 113.46(17) 111.78(13) 105.93(14) 108.50(14) 111.41(16) 110.46(13) 106.62(14) 108.70(14) 104.75(17) 114.72(11) 105.81(14) 110.15(14) 112.09(15) 108.97(13) 106.00(14) 108.35(14) 111.01(25) b 109.52(17) b 109.61(15) b 109.31(14) b

τ see [deg] a

-65.45(14) 175.78(17) 55.83(17) -52.82(17) 36.40(20) -171.94(14) 64.38(19) 46.87(20) -53.37(20) -172.22(28) 173.62(19) 43.88(20) -64.82(20) 67.75(16) -179.76(15) -177.46(20) 64.53(20) -57.83(22) -67.01(16) 166.13(20) 172.51(20) 54.05(35) b -52.63(33) b -54.67(20) b 65.21(22) b

8 Molecules with Six Carbon Atoms

659

The rotational spectrum of the endocyclic 18O-labeled isotopic species of fructose (in an enriched sample) was recorded in a supersonic jet by a laser-ablation Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 18 GHz. The ground-state rotational constants of the 18O isotopic species were used together with the previously determined rotational constants of nine other isotopic species (main, six 13C and two D) to determine the r0 and partial rs structures; the semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. Vogt N, Demaison J, Cocinero EJ, Écija P, Lesarri A, Rudolph HD, Vogt J (2016) The equilibrium molecular structures of 2-deoxyribose and fructose by the semiexperimental mixed estimation method and coupled-cluster computations. Phys Chem Chem Phys 18(23):15555-15563

763 CAS RN: 1245598-96-2 MGD RN: 372598 GED combined with MS and augmented by QC computations

1-Fluoro-1-methylsilacyclohexane C6H13FSi Cs (axial) Cs (equatorial)

Bonds Si–C(1) Si–C(6) C(1)–C(2) C(2)–C(3) C(6)–H(1) C(1)–H(4) C–H Si–F

rh1 [Å] 1.878(4) 1 1.876(4) 1 1.546(5) 2 1.538(5) 2 1.094(3) 3 1.097(3) 3 1.097(3) c 1.630(6)

Bond angles C(1)–Si–F C(1)–Si–C(5) Si–C(1)–C(2) C(1)–Si–C(6) Si–C(6)–H(1) H(1)–C(6)–H(2) H–C–H d

θh1 [deg] a

Dihedral and other angles tilt(CH3) f rock(C(1)) g rock(C(2)) h rock(C(3)) i flap(C(3)) j flap(Si) k C(5)–Si–C(1)–C(2) C(1)–C(2)–C(3)–C(4) Si–C(1)–C(2)–C(3)

Si

a,b

CH3 F

axial

109.1(8) 107.3(5) 110.7(3) 112.4(5) 109.5(14) 109.4 106.3 c,e

τh1 [deg] a

axial 0.0 e 2.2 e 0.0 e 0.2 e 58.0(37) 34.9(25) -37.2(28) -67.7(45) 53.2(16)

Copyright 2010 with permission from Elsevier.

equatorial

56.2(25) 34.1(23) -36.5(25)

equatorial

660

8 Molecules with Six Carbon Atoms

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; difference between parameters in each group was assumed at the value from MP2/6-31G** computation. c Average value. d In the CH2 groups. e Restrained to computed value. f Tilt angle of the CH3 group defined as 2/3[∠(Si–C(6)–H(1)) − ∠(Si–C(6)–H(2))]. g Rock angle of the CH2 group at the C(1) atom defined as 1/2[∠(Si–C(1)–H(4)) − ∠(Si–C(1)–H(5)) + ∠(C(2)– C(1)–H(4)) − ∠(C(2)–C(1)–H(5))]. h Rock angle of the CH2 group at the C(2) atom defined as 1/2[∠(C(1)–C(2)–H(8)) − ∠(C(1)–C(2)–H(9)) + ∠(C(3)–C(2)–H(8)) − ∠(C(3)–C(2)–H(9))]. i Rock angle of the CH2 group at the C(3) atom defined as 1/2[∠(C(2)–C(3)–H(6)) − ∠(C(2)–C(3)–H(7)) + ∠(C(4)–C(3)–H(6)) − ∠(C(4)–C(3)–H(7))]. j Acute angle between the C(1)C(2)C(4)C(5) and C(2)C(3)C(4) planes. k Acute angle between the C(1)C(2)C(4)C(5) and C(1)SiC(5) planes. The GED experiment was carried out at Tnozzle = 282 K. The title compound was found to exist as a mixture of two conformers, characterized by the axial and equatorial positions of the methyl group. The ratio of the conformers was determined to be axial : equatorial = 45(5) : 55(5) (in %) corresponding to ∆G = Gaxial − Gequatorial = 0.11(13) kcal mol−1. Total Cs symmetry, chair conformation of the ring and local C3v symmetry for the methyl group were assumed in the GED analysis. Vibrational corrections to experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force field from MP2/6-31G** computation. Differences between structural parameters of the conformers were assumed at the computed values except for dihedral angles refined independently (see table). Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Girichev GV, Giricheva NI, Hassler K, Arnason I (2010) Conformational properties of 1-fluoro-1-methyl-silacyclohexane and 1-methyl-1-trifluoromethyl-1silacyclohexane: Gas electron diffraction, low-temperature NMR, temerature-dependent Raman spectroscopy, and quantum chemical calculations. J Mol Struct 978 (1-3):209-219

764 CAS RN: 39858-43-0 MGD RN: 216610 MW augmented by ab initio calculations

Cyclohexylgermane Germylcyclohexane C6H14Ge Cs GeH3

Bonds C(1)–C(10) C(10)–C(16) C(4)–C(16) C(4)–Ge C(1)–H(9) C(1)–H(8) C(10)–H(6) C(10)–H(7) C(16)–H(5) C(16)–H(4) C(4)–H(3) Ge–H(1) Ge–H(2)

r0 [Å] a 1.533(3) 1.532(3) 1.540(3) 1.957(3) 1.099(3) 1.096(3) 1.098(3) 1.096(3) 1.100(3) 1.097(3) 1.101(3) 1.533(3) 1.532(3)

8 Molecules with Six Carbon Atoms

Bond angles C(10)–C(1)–C(11) C(1)–C(10)–C(16) C(4)–C(16)–C(10) C(16)–C(4)–C(17) Ge–C(4)–C(16) C(10)–C(1)–H(9) C(10)–C(1)–H(8) H(9)–C(1)–H(8) C(1)–C(10)–H(6) C(1)–C(10)–H(7) C(16)–C(10)–H(6) C(16)–C(10)–H(7) H(6)–C(10)–H(7) C(4)–C(16)–H(5) C(4)–C(16)–H(4) C(10)–C(16)–H(5) C(10)–C(16)–H(4) H(5)–C(16)–H(4) C(16)–C(4)–H(3) Ge–C(4)–H(3) C(4)–Ge–H(1) C(4)–Ge–H(2) H(2)–Ge–H(2) H(1)–Ge–H(2) Dihedral angle C(1)–C(10)–C(16)–C(4)

661

θ0 [deg] a 111.1(5) 111.2(5) 111.3(5) 110.7(5) 111.1(5) 109.0(5) 110.4(5) 106.9(5) 109.2(5) 110.4(5) 108.8(5) 110.0(5) 107.0(5) 109.1(5) 110.5(5) 108.6(5) 110.3(5) 106.8(5) 108.3(5) 107.0(5) 109.1(5) 110.7(5) 109.0(5) 108.6(5)

τ0 [deg] a

-55.6(10)

Reprinted with permission. Copyright 2009 American Chemical Society. a

Parenthesized estimated uncertainties in units of the last significant digit.

The rotational spectrum of cyclohexylgermane was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 10.5 and 21 GHz. The r0 structure was determined by fitting the MP2(full)/6-311+G(d,p) structure to the ground-state rotational constants of three isotopic species (70Ge, 72Ge and 74Ge). Durig JR, Ward RM, Conrad AR, Tubergen MJ, Guirgis GA (2010) Microwave, Raman, and infrared spectra; adjusted r0 structural parameters; conformational stability; and vibrational assignment of germylcyclohexane. J Phys Chem A 114(34):9289-9299

765 CAS RN: 18162-96-4 MGD RN: 128067 MW augmented by QC calculations

Bonds C(1)–C(2) C(2)–C(3) C(4)–C(3) C(4)–Si(6) C(1)–H(2) C(1)–H(1)

Cyclohexylsilane Silylcyclohexane C6H14Si Cs (equatorial) SiH3

r0 [Å] a 1.534(3) 1.530(3) 1.544(3) 1.880(3) 1.099(2) 1.096(2)

662

8 Molecules with Six Carbon Atoms

C(2)–H(8) C(2)–H(9) C(3)–H(6) C(3)–H(7) C(4)–H(5) Si(6)–H(3) Si(6)–H(4)

1.098(2) 1.096(2) 1.110(2) 1.097(2) 1.102(2) 1.487(2) 1.486(2)

Bond angles C(2)–C(1)–C C(1)–C(2)–C(3) C(4)–C(3)–C(2) C(3)–C(4)–C Si(6)–C(4)–C(3) C(2)–C(1)–H(2) C(2)–C(1)–H(1) H(2)–C(1)–H(1) C(1)–C(2)–H(8) C(1)–C(2)–H(9) C(3)–C(2)–H(8) C(3)–C(2)–H(9) H(8)–C(2)–H(9) C(4)–C(3)–H(6) C(4)–C(3)–H(7) C(2)–C(3)–H(6) C(2)–C(3)–H(7) H(6)–C(3)–H(7) C(3)–C(4)–H(5) Si(6)–C(4)–H(5) C(4)–Si(6)–H(3) C(4)–Si(6)–H(4) H(4)–Si(6)–H(9) H(3)–Si(6)–H(4)

θ0 [deg] a

Dihedral angle C(1)–C(2)–C(3)–C(4)

τ0 [deg] a

111.0(5) 111.1(5) 111.5(5) 110.3(5) 111.6(5) 109.2(5) 110.3(5) 106.8(5) 109.2(5) 110.4(5) 109.2(5) 110.0(5) 107.0(5) 109.1(5) 110.5(5) 108.9(5) 110.0(5) 106.7(5) 107.9(5) 107.2(5) 109.4(5) 110.6(5) 108.9(5) 108.6(5)

56.0(10)

Copyright 2009 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 11 and 21 GHz. The r0 structural parameters were determined for the most stable conformer, chair-equatorial, by fitting the MP2_full/6-311+G(d,p) structure to the ground-state rotational constants of three isotopic species (main, 29Si and 30 Si); all C–H distances were fixed in the fit at the ab initio values, whereas all Si–H distances were estimated by means of their correlation with the stretching frequencies. Two conformers, chair-equatorial and chair-axial, were identified in the temperature-dependent IR vibrational spectra. The percentage of the axial conformer was estimated to be 12.7(1) % at ambient temperature. Durig JR, Ward RM, Conrad AR, Tubergen MJ, Giurgis GA, Gounev TK (2009) Microwave spectra, r0 structural parameters, and conformational stability from xenon solutions of silylcyclohexane. J Mol Struct 922(13):19-29

8 Molecules with Six Carbon Atoms

766 CAS RN: 136478-39-2 MGD RN: 208528 GED augmented by QC computations

663

[2-(Dimethylamino)ethanolato-N,O]dimethylgallium C6H16GaNO C1

H 3C

CH3 N

Bonds Ga–O(4) Ga–C(2) Ga–C(3) O(4)–C(5) C(5)–C(6) C(6)–N(7) N(7)–C(8) N(7)–C(9) Ga...N(7) C–H

rh1 [Å] a 1.906(4) b 2.006(2) b 2.006(2) b 1.415(5) c 1.545(5) c 1.500(4) c 1.488(4) c 1.490(4) c 2.332(11) 1.084(2) d,e

Bond angles O(4)–Ga–C(2) O(4)–Ga–C(3) Ga–O(4)–C(5) O(4)–C(5)–C(6) C(5)–C(6)–N(7) C(6)–N(7)–C(8) C(6)–N(7)–C(9) Ga–C–H N–C(6)–H H–C(5)–H H–C(6)–H

θh1 [deg] a

Dihedral angles Ga–O(4)–C(5)–C(6) O(4)–C(5)–C(6)–N(7) C(5)–C(6)–N(7)–C(9) C(5)–C(6)–N(7)–C(8) C(2)–Ga–O(4)–C(5) C(3)–Ga–O(4)–C(5)

τh1 [deg] a

Ga O

CH3 CH3

115.3(8) f 112.8(8) f 116.2(12) d 110.9(9) d,g 109.7(9) d,g 110.7(7) h 110.3(7) h 110.8(9) d,e,g 109.8(11) d,e,g 106.7(11) d,g 108.9(11) d,g

43.0(19) d -48.1(25) d -81.5(21) d 144.8(20) d 86.5(15) d,g -117.3(15) d,g

Reprinted with permission. Copyright 2012 American Chemical Society [a].

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Differences between the Ga–O and Ga–C bond lengths were restrained to the values from MP2_full/6-311+G* calculation. c Differences between the C–O, C–N and C–C bond lengths were restrained to the values from computation as indicated above. d Independent parameter. e Average value. f Difference between the O–Ga–C bond angles was restrained to the value from computation as indicated above. g Restrained to the value from computation as indicated above. h Difference between the C(6)–N(7)–C angles was restrained to the value from computation as indicated above. b

At the temperature of the experiment (Tnozzle = 398…413 K), the title molecules were observed only in the monomeric form. The molecular structure exhibits five-membered ring formed by a dative bond between Ga and the donor atom N.

664

8 Molecules with Six Carbon Atoms

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/6-311+G* calculation. a. Knapp CE, Wann DA, Bil A, Schirlin JT, Robertson HE, McMillan PF, Rankin DWH, Carmalt CJ (2012) Dimethylalkoxygallanes: Monomeric versus dimeric gas-phase structures. Inorg Chem 51 (5):3324-3331 See also: b. Knapp CE, Carmalt CJ, McMillan PF, Wann DA, Robertson HE, Rankin DWH (2008) Dimethylalkoxygallane incorporating a donor-functionalised alkoxide: the monomeric gas-phase structure. Dalton Trans 6880-6882.

767 CAS RN: MGD RN: 308460 MW augmented by ab initio calculations

Angles O–H…O

βb

θ0 [deg] a

2-Methyl-2-propanol – 1,1'-oxybismethane (1/1) tert-Butanol – dimethyl ether (1/1) C6H16O2 Cs H 3C

H3C

CH3

OH

O H 3C

CH3

174.3 139.1

Copyright 2011 with permission from Elsevier.

a

Uncertainties were not given in the original paper. Angle between the bisector of the C–O–C angle and the O…H hydrogen bond.

b

The rotational spectra of the title complex were recorded by a pulsed-jet FTMW spectrometer in the spectral region between 7 and 18 GHz. The partial r0 structure was determined from ground state rotational constants of the main isotopic species; the remaining structural parameters were assumed at the values of the MP2/6-311+G(d,p) structure. The O…O distance was found to become shorter by 0.0055 Å upon deuteration (Ubbelohde effect). Evangelisti L, Caminati W (2011) The shape of the molecular adduct tert-butyl alcohol-dimethyl ether: A rotational study. J Mol Spectrosc 270(2):120-122

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698 699 700 701 702 703 704 705 706 707 708

709 710 711

712

713 714 715 716 717 718

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720 721 722 723 724 725 726 727 728 729

730

731 732 733

734 735

736 737

668

8 Molecules with Six Carbon Atoms

738 739 740 741 742 743 744 745 746 747 748 749 750 751

752 753

754

755 756

757

Sawant DK, Klaassen JJ, Gounev TK, Durig JR (2015) r0 Structural parameters, conformational, vibrational studies and ab initio calculations of cyanocyclopentane. Spectrochim Acta A 151:468-479 Durig JR, Klaassen JJ, Sawant DK, Deodhar BS, Panikar SS, Gurusinghe RM, Darkhalil ID, Tubergen MJ (2015) Microwave, structural, conformational, vibrational studies and ab initio calculations of isocyanocyclopentane. Spectrochim Acta A 136:3-15 Gou Q, Spada L, Vallejo-López M, Lesarri A, Cocinero EJ, Caminati W (2014) Interactions between alkanes and aromatic molecules: a rotational study of pyridine-methane. Phys Chem Chem Phys 16(26):13041-13046 See 731. Frohman DJ, Novick SE, Pringle WC (2013) Rotational spectrum and structure of cyclohexene oxide and the argon-cyclohexene oxide van der Waals complex. J Phys Chem A 117(50):13691-13695 Shlykov SA, Phien TD, Weber PM (2017) Intramolecular inversions, structure and conformational behavior of gaseous and liquid N-cyanopiperidine. Comparison with other 1cyanoheterocyclohexanes. J Mol Struct 1138:41-49 Ksenafontov DN, Moiseeva NF, Khristenko LV, Karasev NM, Shishkov IF, Vilkov LV (2010) The structure and conformations of piracetam (2-oxo-1-pyrrolidineacetamide): Gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 984 (1-3):89-95 Belova NV, Girichev GV, Oberhammer H, Trang NH, Shlykov SA (2012) Tautomeric properties and gas-phase structure of 3-methyl-2,4-pentanedione. J Mol Struct 1023:49-54 Jahn MK, Dewald DA, Vallejo-López M, Cocinero EJ, Lesarri A, Zou W, Cremer D, Grabow JU (2014) Pseudorotational landscape of seven-membered rings: the most stable chair and twist-boat conformers of ε-caprolactone. Chem Eur J 20(43):14084-14089 Domingos SR, Pérez C, Schnell M (2017) On the structural intricacies of a metabolic precursor: Direct spectroscopic detection of water-induced conformational reshaping of mevalonolactone. J Chem Phys 147(12):124310/1-124310/6 Durig JR, El Defrawy AM, Ward RM, Guirgis GA, Gounev TK (2009) Conformational stability of bromocyclohexane from temperature dependent FT-IR spectra of xenon solutions, r0 structural parameters and vibrational assignment. J Mol Struct 918(1-3):26-38 Durig JR, El Defrawy AM, Ward RM, Guirgis GA, Gounev TK (2008) Conformational stability of chlorocyclohexane from temperature-dependent FT-IR spectra of xenon solutions, r0 structural parameters, and vibrational assignment. Struct Chem 19(4):579-594 Juanes M, Vogt N, Demaison J, Leon I, Lesarri A, Rudolph HD (2017) Axial-equatorial isomerism and semiexperimental equilibrium structures of fluorocyclohexane. Phys Chem Chem Phys 19(43):29162-29169 (a) Evangelisti L, Lesarri A, Jahn MK, Cocinero EJ, Caminati W, Grabow JU (2011) N-Methyl inversion and structure of six-membered heterocyclic rings: Rotational spectrum of 1-methyl4-piperidone. J Phys Chem A 115(34):9545-9551 (b) Demaison J, Craig NC, Cocinero EJ, Grabow JU, Lesarri A, Rudolph HD (2012) Semiexperimental equilibrium structures for the equatorial conformers of N-methylpiperidone and tropinone by the mixed estimation method. J Phys Chem A 116(34):8684-8692 Foerster T, Wann DA, Robertson HE, Rankin DWH (2009) Why are trimethylsilyl groups asymmetrically coordinated? Gas-phase molecular structures of 1-trimetylsilyl-1,2,3benzotriazole and 2-trimethylsilyl-1,3-thiazole. Dalton Trans 16:3026-3033 Belyakov AV, Sigolaev YF, Shlykov SA, Wallevik SÓ, Jonsdottir NR, Jonsdottir S, Kvaran Á, Bjornsson R, Arnason I (2017) Conformational properties of 1-cyano-1-silacyclohexane, C5H10SiHCN: Gas electron diffraction, low-temperature NMR and quantum chemical calculations. J Mol Struct 1132:149-156 Durig JR, Zheng C, El Defrawy AM, Ward RM, Gounev TK, Ravindranath K, Rao NR (2009) On the relative intensities of the Raman active fundamentals, r0 structural parameters, and pathway of chair-boat interconversion of cyclohexane and cyclohexane-d12. J Raman Spectrosc 40(2):197-204 Rezaei M, Michaelian KH, McKellar ARW, Moazzen-Ahmadi N (2012) Infrared spectra of ethylene clusters: (C2D4)2 and (C2D4)3. Phys Chem Chem Phys 14(23):8415-8418 Masters SL, Robertson HE, Wann DA, Hölbling M, Hassler K, Bjornsson R, Wallevik SÓ, Arnason I (2015) Molecular structure of 1,2-bis(trifluoromethyl)-1,1,2,2-tetramethyldisilane in the gas, liquid, and solid phases: Unusual conformational changes between phases. J Phys Chem A 119 (9):1600-1608 Vishnevskiy YV, Schwabedissen J, Rykov AN, Kuznetsov VV, Makhova NN (2015) Conformational and bonding properties of 3,3-dimethyl- and 6,6-dimethyl-1,5-

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760 761 762

763

764 765 766

767

669

diazabicyclo[3.1.0]hexane: A case study employing the Monte Carlo method in gas electron diffraction. J Phys Chem A 119 (44):10871-10881 See 757. Khaikin LS, Grikina OE, Karasev NM, Kovtun DM, Kochikov IV (2014) Electron diffraction study of the equilibrium structure of hexamethylenetetramine involving data from quantum chemistry and vibrational spectroscopy. Russ J Phys Chem A / Zh Fiz Khim 88 / 88 (4 / 4):652-656 / 638-642 Seifert NA, Finneran IA, Perez C, Zaleski DP, Neill JL, Steber AL, Suenram RD, Lesarri A, Shipman ST, Pate BH (2015) AUTOFIT, an automated fitting tool for broadband rotational spectra, and applications to 1-hexanal. J Mol Spectrosc 312:13-21 Evangelisti L, Velino B, Feng G, Gou Q, Caminati W (2014) Adducts of alcohols with ketones: a rotational study of the molecular complex ethylalcohol-cyclobutanone. J Mol Spectrosc 299:38-42 Vogt N, Demaison J, Cocinero EJ, Écija P, Lesarri A, Rudolph HD, Vogt J (2016) The equilibrium molecular structures of 2-deoxyribose and fructose by the semiexperimental mixed estimation method and coupled-cluster computations. Phys Chem Chem Phys 18(23):1555515563 Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Girichev GV, Giricheva NI, Hassler K, Arnason I (2010) Conformational properties of 1-fluoro-1-methyl-silacyclohexane and 1methyl-1-trifluoromethyl-1-silacyclohexane: Gas electron diffraction, low-temperature NMR, temerature-dependent Raman spectroscopy, and quantum chemical calculations. J Mol Struct 978 (1-3):209-219 Durig JR, Ward RM, Conrad AR, Tubergen MJ, Guirgis GA (2010) Microwave, Raman, and infrared spectra; adjusted r0 structural parameters; conformational stability; and vibrational assignment of germylcyclohexane. J Phys Chem A 114(34):9289-9299 Durig JR, Ward RM, Conrad AR, Tubergen MJ, Giurgis GA, Gounev TK (2009) Microwave spectra, r0 structural parameters, and conformational stability from xenon solutions of silylcyclohexane. J Mol Struct 922(1-3):19-29 (a) Knapp CE, Wann DA, Bil A, Schirlin JT, Robertson HE, McMillan PF, Rankin DWH, Carmalt CJ (2012) Dimethylalkoxygallanes: Monomeric versus dimeric gas-phase structures. Inorg Chem 51 (5):3324-3331 (b) Knapp CE, Carmalt CJ, McMillan PF, Wann DA, Robertson HE, Rankin DWH (2008) Dimethylalkoxygallane incorporating a donor-functionalised alkoxide: the monomeric gasphase structure. Dalton Trans 6880-6882 Evangelisti L, Caminati W (2011) The shape of the molecular adduct tert-butyl alcoholdimethyl ether: A rotational study. J Mol Spectrosc 270(2):120-122

Chapter 9. Molecules with Seven to Nine Carbon Atoms

768 CAS RN: 773-82-0 MGD RN: 145120 MW augmented by ab initio calculations

2,3,4,5,6-Pentafluorobenzonitrile

F

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–C(7) C(7)≡N

r0 [Å] a 1.400(2) 1.372(3) 1.393(2) 1.434(3) 1.156(2)

rs [Å] a 1.400(2) 1.359(3) 1.391(1) 1.435(1) 1.157(1)

Bond angles

θ0 [deg] a

θs [deg] a

121.3(5) 119.7(2) 120.1(2) 119.0(4) 121.0(3)

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(6)–C(1)–C(2) C(7)–C(1)–C(2)

C7F5N C2v

F

F

C

F

N

F

121.6(2) 119.8(1) 119.8(1) 117.4(2) 121.3(2)

Reprinted with permission. Copyright 2015 American Chemical Society. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of 2,3,4,5,6-pentafluorobenzonitrile was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the region between 4 and 24 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 15N and five 13C); the remaining structural parameters were constrained to the values MP2/6311++G(2d,2p) calculations. The partial rs structure was also determined. Kamaee M, Sun M, Luong H, van Wijngaarden J (2015) Investigation of structural trends in mono-, di-, and pentafluorobenzonitriles using Fourier transform microwave spectroscopy. J Phys Chem A 119(41):1027910292 769 CAS RN: 355-02-2 MGD RN: 374451 GED supported by ab initio computations

1,1,2,2,3,3,4,4,5,5,6-Undecafluoro-6-(trifluoromethyl)cyclohexane C7F14 Cs (equatorial) F

F F

F F

a

Bonds C–C C–F

rh1 [Å] 1.548(2) b,c 1.340(1) b,c

Bond angles C–C–C C–C–F β[C(1),C(4)] e

θh1 [deg] a

CF3 F

F F

F F

F

113.1(3) b,c 109.6(2) b,d 132.4(4)

© Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_9

671

672

9 Molecules with Seven to Nine Carbon Atoms

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. b Average value. c Differences between the averaged parameters were fixed at the values from MP2/6-311+G* computation. d Average difference between the C–C–F bond angles was restrained to the value from computation as above. e Average value of the C(1)…Y…X and C(4)…X…Y angles, where X and Y are the midpoints between C(3) and C(5) and between C(2) and C(6), respectively. Difference between these parameters was restrained to the value from computation as above. The GED experiment was carried out at the nozzle temperatures of 429 and 450 K at the long and short nozzleto-film distances, respectively. Following to results of HF/3-21G* computations, only one conformer with the CF3 group in the equatorial position with respect to the ring was considered in the GED analysis. This conformer was predicted to be lower in energy by 25 kJ mol−1 in comparison to the axial conformer. Vibrational corrections to the experimental internuclear distances, ∆rh1= ra − rh1, were calculated using harmonic force constants from HF/6-31G* computation. Kafka GR, Masters SL, Wann DA, Robertson HE, Rankin DWH (2010) Low symmetry in molecules with heavy peripheral atoms. The gas-phase structure of perfluoro(methylcyclohexane), C6F11CF3. J Phys Chem A 114 (41):11022-11026

770 CAS RN: 21524-39-0 MGD RN: 132070 MW augmented by ab initio calculations

2,3-Difluorobenzonitrile

F

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–C(7) C(7)≡N

r0 [Å] a 1.386(7) 1.389(3) 1.381(4) 1.398(4) 1.396(6) 1.404(8) 1.437(4) 1.158 b

rs [Å] a 1.375(11) 1.391(14) 1.366(8) 1.400(2) 1.387(3) 1.409(4) 1.438(2) 1.158 b

Bond angles

θ0 [deg] a

θs [deg] a

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(7)–C(1)–C(2) N≡C(7)–C(1)

119.9(3) 121.3(3) 119.0(2) 120.4(2) 119.5(5) 119.8(8) 120.1(6) 179.5(7)

119.6(5) 121.8(5) 118.9(1) 120.3(1) 119.7(2) 119.7(5) 121.0(5) 179.1(3)

Reprinted with permission. Copyright 2015 American Chemical Society.

C7H3F2N Cs F

C

N

9 Molecules with Seven to Nine Carbon Atoms a b

673

Parenthesized uncertainties in units of the last significant digit. Constrained to average value of other fluorobenzonitriles.

The rotational spectrum of 2,3-difluorobenzonitrile was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 24 GHz. The partial r0 structure of the benzonitrile skeleton was determined from the ground-state rotational constants of nine isotopic species (main, 15N and seven 13C); the remaining structural parameters were constrained to the values from MP2/6-311++G(2d,2p) calculation. The partial rs structure was also determined. Kamaee M, Sun M, Luong H, van Wijngaarden J (2015) Investigation of structural trends in mono-, di-, and pentafluorobenzonitriles using Fourier transform microwave spectroscopy. J Phys Chem A 119(41):1027910292

771 CAS RN: 3939-09-1 MGD RN: 462310 MW augmented by ab initio calculations

2,4-Difluorobenzonitrile C7H3F2N Cs

F

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–C(7) C(7)≡N

r0 [Å] a 1.385(6) 1.376(5) 1.393(4) 1.386(4) 1.398(16) 1.402(11) 1.437(4) 1.158(2)

rs [Å] a 1.387(4) 1.357(5) 1.370(13) 1.409(15) 1.393(25) 1.403(15) 1.440(1) 1.158(1)

Bond angles

θ0 [deg] a

θs [deg] a

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(7)–C(1)–C(2) N≡C(7)–C(1)

122.9(3) 116.8(3) 123.2(7) 118.2(1) 120.1(8) 118.8(4) 121.2(6) 179.3(5)

F

C

N

123.5(3) 117.4(4) 122.8(2) 117.9(3) 120.0(7) 118.4(9) 121.7(8) 179.2(3)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of 2,4-difluorobenzonitrile was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 24 GHz. The partial r0 structure of the benzonitrile skeleton was determined from the ground-state rotational constants of nine isotopic species (main, 15N and seven 13C); the remaining structural parameters were constrained to the values from MP2/6-311+++G(2d,2p) calculations. The partial rs structure was also obtained. Kamaee M, Sun M, Luong H, van Wijngaarden J (2015) Investigation of structural trends in mono-, di-, and pentafluorobenzonitriles using Fourier transform microwave spectroscopy. J Phys Chem A 119(41):1027910292

674

9 Molecules with Seven to Nine Carbon Atoms

772 CAS RN: 7154-66-7 MGD RN: 517050 GED augmented by ab initio computations

Bonds C(1)–C(7) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(7)=O C(7)–Cl C(2)–Br C–H c

2-Bromobenzoyl chloride C7H4BrClO C1 (anti) C1 (gauche)

anti 1.491(1) 1.411(1) 1.402(1) 1.389(11) 1.409(11) 1.396(1) 1.407(1) 1.216(5) 1.809(7) 1.889(6) 1.103(12)

θh1 [deg] a,b

Bond angles C(1)–C(7)=O C(1)–C(7)–Cl C–C–C (ring) c C(1)–C(2)–Br C(7)–C(1)–C c C–C–H c Dihedral angle C(2)–C(1)–C(7)–Cl

rh1 [Å] a,b gauche 1.494(1) 1.402(1) 1.400(1) 1.391(11) 1.409(11) 1.398(1) 1.404(1) 1.217(5) 1.794(7) 1.889(6) anti

126.2(8) 115.1(7) 119.3(19) 126.3(20) 119.9(6) 120.0 d

τh1 [deg] a

anti -143.4(11)

Reproduced with permission of SNCSC.

gauche 95.2(170)

gauche

a

Parenthesized uncertainties in units of the last significant digit are 2σ values. Differences between chemically equivalent bond lengths in each conformer and between the conformers were fixed at the values from MP2/6-311G(d) computation. c Average value. d Fixed at the value from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle = 425 K. The title compound was found to exist as a mixture of anti (57(9) %) and gauche (43(9) %) conformers, characterized by the antiperiplanar and synclinal C(2)–C(1)–C(7)–Cl torsional angles, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from computation at the level of theory as indicated above. In addition, anharmonic vibrational corrections to the bond length were taken into account using anharmonic force constants from the literature. Thus, the determined structure is rather re than rh1 as denoted in the original paper. Johansen TH, Dahl PI, Hagen K (2013) Molecular conformational structures of 2-fluorobenzoyl chloride, 2chlorobenzoyl chloride, and 2-bromobenzoyl chloride by gas electron diffraction and normal coordinate analysis aided by quantum chemical calculations. Struct Chem 24 (3):789-805

9 Molecules with Seven to Nine Carbon Atoms

675

773 CAS RN: 393-52-2 MGD RN: 516691 GED augmented by ab initio computations

Bonds C(1)–C(7) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(7)=O C(7)–Cl C(2)–F C–H c

2-Fluorobenzoyl chloride C7H4ClFO essentially Cs (anti) C1 (gauche)

rh1 [Å] a,b anti gauche 1.483(2) 1.486(2) 1.405(2) 1.400(2) 1.391(2) 1.392(2) 1.406(5) 1.407(5) 1.389(5) 1.389(5) 1.394(2) 1.393(2) 1.405(2) 1.407(2) 1.193(4) 1.198(4) 1.801(4) 1.773(4) 1.331(11) 1.334(11) 1.105(9)

Bond angles C(1)–C(7)=O C(1)–C(7)–Cl C–C–C (ring) c C(1)–C(2)–F C(7)–C(1)–C c C–C–H c Dihedral angle C(2)–C(1)–C(7)–Cl

anti

θh1 [deg]

124.7(5) 114.8(3) 119.8(8) 118.5(13) 120.8(4) 120.3 d

anti -179.9(6)

Reproduced with permission of SNCSC.

τh1 [deg] a

gauche 44.4(24)

gauche

a

Parenthesized uncertainties in units of the last significant digit are 2σ values. Differences between chemically equivalent bond lengths in the conformer and between the conformers were fixed at the values from MP2/6-31G(d) computation. c Average value. d Fixed at the value from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle = 386 K. The title compound was found to exist as a mixture of anti (65(12)%) and gauche (35(12)%) conformers, characterized by the antiperiplanar and synclinal C(2)–C(1)– C(7)–Cl torsional angles, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from computation at the level of theory as indicated above. In addition, anharmonic vibrational corrections to the bond length were taken into account using anharmonic force constants from the literature. Thus, the determined structure is rather re than rh1 as denoted in the original paper. Johansen TH, Dahl PI, Hagen K (2013) Molecular conformational structures of 2-fluorobenzoyl chloride, 2chlorobenzoyl chloride, and 2-bromobenzoyl chloride by gas electron diffraction and normal coordinate analysis aided by quantum chemical calculations. Struct Chem 24 (3):789-805

676

9 Molecules with Seven to Nine Carbon Atoms

774 CAS RN: 609-65-4 MGD RN: 516875 GED augmented by ab initio computations

Bonds C(1)–C(7) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(7)=O C(7)–Cl C(2)–Cl C–H c

2-Chlorobenzoyl chloride C7H4Cl2O C1 (anti) C1 (gauche)

anti 1.486(1) 1.408(1) 1.397(1) 1.393(3) 1.399(3) 1.393(1) 1.405(1) 1.203(3) 1.799(2) 1.733(2) 1.101(9)

Bond angles C(1)–C(7)=O C(1)–C(7)–Cl C(1)–C(2)–Cl C–C–C (ring) c C(7)–C(1)–C c C–C–H c Dihedral angle C(2)–C(1)–C(7)–Cl

rh1 [Å] a,b gauche 1.489(1) 1.403(1) 1.398(1) 1.394(3) 1.399(3) 1.393(1) 1.405(1) 1.207(3) 1.778(2) 1.735(2) anti

θh1 [deg] 126.8(4) 114.2(4) 122.1(5) 120.2 d 120.3(4) 120.0 d

τh1 [deg] a

anti -150.1(13)

gauche

gauche 63.5(9)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are 2σ values. Differences between chemically equivalent bond lengths in each conformer and between the conformers were fixed at the values from MP2/6-31G(d) computation. c Average value. d Fixed at the value from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle = 410 K. The title compound was found to exist as a mixture of anti (66(3)%) and gauche (34(3)%) conformers, characterized by the antiperiplanar and synclinal C(2)–C(1)–C(7)–Cl torsional angles, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from computation at the level of theory as indicated above. In addition, the bond lengths were corrected for anharmonic vibrational effects estimated from anharmonic force constants taken from the literature. Thus, the determined structure is rather re than rh1. Johansen TH, Dahl PI, Hagen K (2013) Molecular conformational structures of 2-fluorobenzoyl chloride, 2chlorobenzoyl chloride, and 2-bromobenzoyl chloride by gas electron diffraction and normal coordinate analysis aided by quantum chemical calculations. Struct Chem 24 (3):789-805

9 Molecules with Seven to Nine Carbon Atoms

677

775

2-Fluorobenzonitrile o-Fluorobenzonitrile C7H4FN

CAS RN: 394-47-8

MGD RN: 368628 MW augmented by ab initio calculations

Cs

F

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–C(7) C(7)≡N

r0 [Å] a 1.383(4) 1.384(2) 1.397(4) 1.397(4) 1.394(3) 1.402(5) 1.443(5) 1.157(1)

rs [Å] a

Bond angles

θ0 [deg] a

θs [deg] a

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(7)–C(1)–C(2) N≡C(7)–C(1)

122.1(2) 118.4(2) 120.6(1) 120.0(1) 119.6(3) 119.2(2) 120.7(3) 179.2(3)

N

C

1.383(4) 1.384(2) 1.397(4) 1.397(4) 1.394(3) 1.402(5) 1.443(5) 1.157(1)

122.1(2) 118.4(2) 120.6(1) 120.0(1) 119.6(3) 119.2(2) 120.7(3) 179.2(3)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of 2-fluorobenzonitrile was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 24 GHz. The partial r0 structure of the benzonitrile skeleton was determined from the ground-state rotational constants of nine isotopic species (main, 15N and seven 13C); the remaining structural parameters were constrained to the values from MP2/6-311G(2d,2p) calculation. The partial rs structure was also determined. Kamaee M, Sun M, Luong H, van Wijngaarden J (2015) Investigation of structural trends in mono-, di-, and pentafluorobenzonitriles using Fourier transform microwave spectroscopy. J Phys Chem A 119(41):1027910292

776 CAS RN: 403-54-3 MGD RN: 116124 MW augmented by ab initio calculations

3-Fluorobenzonitrile m-Fluorobenzonitrile C7H4FN Cs F C

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5)

r0 [Å] a 1.398(10) 1.388(7) 1.386(3) 1.396(4)

rs [Å] a 1.393(14) 1.386(14) 1.380(4) 1.398(2)

N

678

9 Molecules with Seven to Nine Carbon Atoms

C(5)–C(6) C(6)–C(1) C(1)–C(7) C(7)≡N

1.397(6) 1.392(11) 1.447(5) 1.158(3)

1.389(3) 1.393(13) 1.447(5) 1.158(2)

Bond angles

θ0 [deg] a

θs [deg] a

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(7)–C(1)–C(2) N≡C(7)–C(1)

117.1(5) 123.2(2) 118.3(2) 120.6(2) 119.0(9) 121.8(8) 118.6(9) 179.7(10)

117.0(5) 123.3(3) 118.2(1) 120.5(1) 119.2(2) 121.7(5) 118.8(8) 179.8(6)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of 3-fluorobenzonitrile was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 24 GHz. The partial r0 structure of the benzonitrile skeleton was determined from the ground-state rotational constants of nine isotopic species (main, 15N and seven 13C); the remaining structural parameters were constrained to the values from MP2/6-311++G(2d,2p) calculation. The partial rs structure was also determined. Kamaee M, Sun M, Luong H, van Wijngaarden J (2015) Investigation of structural trends in mono-, di-, and pentafluorobenzonitriles using Fourier transform microwave spectroscopy. J Phys Chem A 119(41):1027910292

777 CAS RN: 98-08-8 MGD RN: 383969 MW

Bonds C(2)–C(3) C(3)–C(4)

(Trifluoromethyl)benzene Benzotrifluoride C7H5F3 Cs F

rs [Å] a 1.399(3) 1.406(3)

F

F

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by an FTMW spectrometer in the spectral range between 6 and 18.0 GHz. The partial rs structure was determined from the ground-state rotational constants of five isotopic species (main and four 13C). Favero L, Caminati W, Grabow JU (2009) The m=0 state of the low-barrier torsion in α,α,α-trifluorobenzene (benzotrifluoride). J Mol Spectrosc 255(2):199-201

9 Molecules with Seven to Nine Carbon Atoms

778 CAS RN: 456-55-3 MGD RN: 147506 MW supported by ab initio calculations

679

(Trifluoromethoxy)benzene α,α,α-Trifluoroanisole C7H5F3O essentialy Cs O

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–O(7) O(7)–C(8)

rs [Å] a 1.404(3) 1.398(6) 1.399(3) 1.346(4) 1.340(2)

Bond angles C(2)–C(1)–C(6) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(2)–C(1)–O(7) O(7)–C(1)–C(6) C(1)–O(7)–C(8)

θs [deg] a

Dihedral angles O(7)–C(1)–C(6)…C(2) C(8)–O(7)–C(1)–C(2)

τs [deg] a

F

F

F

119.9(3) 119.7(2) 120.4(2) 119.9(2) 119.9(2) 116.9(2)

174.9(7) 92.5(4)

Copyright 2014 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by pulsed-jet FTMW spectrometers in the frequency region between 3.7 and 26.5 GHz. The rs structure of the carbon-oxygen skeleton was determined from the ground-state rotational constants of seven isotopic species (main, five 13C and 18O). Kang L, Novick SE, Gou Q, Spada L, Vallejo-López M, Caminati W (2014) The shape of trifluoromethoxybenzene. J Mol Spectrosc 297:32-34

779 CAS RN: 100-47-0 MGD RN: 597150 MW augmented by DFT calculations

Cyanobenzene Benzonitrile C 7H 5N C2v C

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–C(7) C(7)≡N C(2)–H C(3)–H

[Å] a r (1) m 1.389(2) 1.395(2) 1.395(1) 1.449(2) 1.1574(7) 1.077(2) 1.0808(7)

r see [Å] a 1.3969(1) 1.3881(2) 1.3915(1) 1.4343(2) 1.15829(6) 1.0780(2) 1.08003(8)

N

680

9 Molecules with Seven to Nine Carbon Atoms

C(4)–H

1.0791(6)

1.07995(5)

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(1)–C(2)–H C(2)–C(3)–H C(4)–C(3)–H

θ (1) [deg] a m

θ see [deg] a

121.9(2) 118.8(1) 120.18(6) 120.10(7) 120.5(3) 119.85(8) 119.97(7)

120.53(2) 119.43(2) 120.274(7) 120.066(6) 119.76(3) 119.62(1) 120.10(1)

Reprinted with permission. Copyright 2013 American Chemical Society [a].

a

Parenthesized uncertainties in units of the last significant digit.

was determined from the previously published experimental ground-state The mass-dependent structure r (1) m rotational constants of ten isotopic species. The semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with harmonic and anharmonic (cubic) force fields from both B3LYP/6-31G* and B3LYP/6-311+G(3df,2pd) computations. a. Rudolph HD, Demaison J, Császár AG (2013) Accurate determination of the deformation of the benzene ring upon substitution: equilibrium structures of benzonitrile and phenylacetylene. J Phys Chem A 117(48):1296912982 MW augmented by ab initio calculations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–C(7) C(7)≡N

r0 [Å] a 1.397(7) 1.397(7) 1.398(6) 1.445(8) 1.158(3)

rs [Å] a 1.381(6) 1.417(12) 1.396(1) 1.450(3) 1.158(1)

Bond angles

θ0 [deg] a

θs [deg] a

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(6)–C(1)–C(2) C(7)–C(1)–C(2)

119.1(5) 120.1(3) 120.2(6) 121.4(5) 119.3(7)

118.1(5) 120.2(1) 120.1(1) 123.4(9) 118.3(1)

Reprinted with permission. Copyright 2015 American Chemical Society [b].

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of benzonitrile was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 24 GHz. The partial r0 structure of the heavy-atom skeleton was determined from the ground-state rotational constants of seven isotopic species (main, 15N and five 13C); the remaining structural parameters were constrained to the values from MP2/6-311++G(2d,2p) calculations. The partial rs structure was also determined.

9 Molecules with Seven to Nine Carbon Atoms

681

b. Kamaee M, Sun M, Luong H, van Wijngaarden J (2015) Investigation of structural trends in mono-, di-, and pentafluorobenzonitriles using Fourier transform microwave spectroscopy. J Phys Chem A 119(41):1027910292

780 CAS RN: 443-84-5 MGD RN: 462715 MW augmented by ab initio calculations

1,3-Difluoro-2-methylbenzene 2,6-Difluorotoluene C7H6F2 Cs F CH3

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–C(7) C–F

r0 [Å] a 1.387(3) 1.380(3) 1.400(5) 1.515(4) 1.358(5)

rs [Å] a 1.36899(8) 1.41816(4) 1.39371(5) 1.50635(4)

Bond angles

θ0 [deg] a

θs [deg] a

C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–C(6) C(2)–C(1)–C(7) C–C–F

124.2(2) 118.0(2) 120.5(1) b 115.1(3) b 122.5 c 117.5(3)

F

122.951(8) 118.270(6) 120.265(8) 117.29(1) 121.354(7)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c MP2/6-311++G(2df,2p) value. b

The rotational spectra of 2,6-difluorotoluene were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 25 GHz. The partial r0 structure was determined for the heavy-atom skeleton from the ground-state rotational constants of six isotopic species (main and five 13C). Moreover, the partial rs structure was obtained for the carbon skeleton. Nair KPR, Jahn MK, Lesarri A, Ilyushin VV, Grabow JU (2015) Six-fold-symmetry internal rotation in toluenes: the low barrier challenge of 2,6- and 3,5-difluorotoluene. Phys Chem Chem Phys 17(39):26463-26470

781 CAS RN: 117358-51-7 MGD RN: 462520 MW augmented by ab initio calculations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–C(7)

1,3-Difluoro-5-methylbenzene 3,5-Difluorotoluene C7H6F2 Cs F

r0 [Å] a 1.403(2) 1.359(15) 1.405(12) 1.509(18)

rs [Å] a 1.40483(5) 1.3677(1) 1.38534(6) 1.51174(4)

CH3

F

682

9 Molecules with Seven to Nine Carbon Atoms

C–F

1.354(9)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–C(6) C(2)–C(1)–C(7) C–C–F

θ0 [deg] a

119.3(2) 123.5(1) 115.1(6) b 119.3(2) b 120.4 c 120.3(10)

θs [deg] a

118.91(1) 123.80(1) 115.602(7) 118.993(6) 120.504(7)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Dependent parameter. c MP2/6-311++G(2df,2p) value. b

The rotational spectra of 3,5-difluorotoluene were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 5 and 25 GHz. The partial r0 structure was determined for the heavy-atom skeleton from the ground-state rotational constants of six isotopic species (main and five 13C). Moreover, the partial substitution structure rs was also obtained for the carbon skeleton. Nair KPR, Jahn MK, Lesarri A, Ilyushin VV, Grabow JU (2015) Six-fold-symmetry internal rotation in toluenes: the low barrier challenge of 2,6- and 3,5-difluorotoluene. Phys Chem Chem Phys 17(39):26463-26470

782 CAS RN: 452-67-5 MGD RN: 543005 MW supported by QC calculations

1,4-Difluoro-2-methylbenzene 2,5-Difluorotoluene C7H6F2 Cs F

Bonds C(1)–C(6) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(7) C(2)–F C(5)–F

rs [Å] a 1.379(3) 1.382(3) 1.407(7) 1.367(10) 1.330(39) 1.436(31) 1.512(2)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(6)–C(1)–C(7) C(2)–C(1)–C(7)

θs [deg] a 122.7(7) 119.2(9) 119(4) 123(4) 118(2) 117.8(4) 122.0(3) 120.4(4)

Copyright 2017 with permission from Elsevier.

r0 [Å] a

1.372(13) 1.371(12)

CH3

F

9 Molecules with Seven to Nine Carbon Atoms a

683

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of 2,5-difluorotoluene was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 4.5 and 24 GHz. The substitution structure rs was determined for the carbon skeleton from the ground-state rotational constants of eight isotopic species (main and seven 13C). Both r0(C–F) distances were obtained from a least-squares fit of eight sets of rotational constants, keeping the substitution ring structure fixed and assuming the C–H distances at the values of 1.084 and 1.092 Å in the aromatic and aliphatic moieties, respectively. The barrier to internal rotation of the methyl group was determined from the torsional splittings to be 2.580(12) kJ mol-1. Nair KPR, Wachsmuth D, Grabow JU, Lesarri A (2017) Internal rotation in halogenated toluenes: Rotational spectrum of 2,5-difluorotoluene. J Mol Spectrosc 337(1):46-50

783 CAS RN: MGD RN: 213981 IR

Distance Rcm b

Benzene – carbonyl sulfide – helium (1/1/1) C7H6HeOS C6v O

r0 [Å] a 3.570

C

S

He

Reproduced with permission of AIP Publishing.

a b

Uncertainty was not given in the original paper. Distance between He and the center-of-mass of the benzene subunit.

The rotationally resolved IR spectra of the ternary complex of benzene with carbonyl sulfide and helium were recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the region of the ν1 fundamental band of OCS at about 2050 cm-1. For the study of the OC34S complex an enriched sample was used as precursor. The partial r0 structure was determined under the assumption that the structural parameters of the OCS-C6H6 dimer subunit were not changed upon further complexation. Dehghany M, Norooz Oliaee J, Afshari M, Moazzen-Ahmadi N, McKellar ARW (2010) Infrared spectra of OCS-C6H6, OCS-C6H6-He, and OCS-C6H6-Ne van der Waals complexes. J Chem Phys 132(19):194303/1194303/6 doi:10.1063/1.3430571 784 CAS RN: MGD RN: 214166 IR

Benzene – carbonyl sulfide – neon (1/1/1) C7H6NeOS C6v

684

Distance Rcm b

9 Molecules with Seven to Nine Carbon Atoms

r0 [Å] a 3.443

O

C

Ne

S

Reproduced with permission of AIP Publishing.

a b

Uncertainty was not given in the original paper. Distance between Ne and the center-of-mass of the benzene subunit.

The rotationally resolved IR spectra of the ternary van der Waals complex of benzene with carbonyl sulfide and neon were recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the region of the ν1 fundamental band of OCS at about 2050 cm-1. The partial r0 structure was determined from the ground-state rotational constants of the main isotopic species under the assumption that the structural parameters of the OCS ⋅ C6H6 dimer subunit were not changed upon further complexation. Dehghany M, Norooz Oliaee J, Afshari M, Moazzen-Ahmadi N, McKellar ARW (2010) Infrared spectra of OCS-C6H6, OCS-C6H6-He, and OCS-C6H6-Ne van der Waals complexes. J Chem Phys 132(19):194303/1194303/6 doi:10.1063/1.3430571

785 CAS RN: 162615-08-9 MGD RN: 135925 IR

Distances Rcm b rc

Benzene – carbonyl sulfide (1/1)

r0 [Å] a 4.420 3.381

C7H6OS C6v O

C

S

Reproduced with permission of AIP Publishing.

a

Uncertainties were not given in the original paper. Distance between centers of mass of the monomer subunits. c Distance between the S atom and the center-of-mass of the benzene subunit. b

The rotationally resolved IR spectra of the binary complex of benzene with carbonyl sulfide were recorded in a pulsed supersonic jet by a tunable diode laser spectrometer in the region of the ν1 fundamental band of OCS at about 2050 cm-1. The 34S isotopic species was studied in an enriched sample, whereas the singly substituted 13C isotopic species was investigated in natural abundance. The partial r0 structure was determined from the ground-state rotational constants of three isotopic species assuming that the structural parameters of the monomer subunits were not changed upon complexation. Dehghany M, Norooz Oliaee J, Afshari M, Moazzen-Ahmadi N, McKellar ARW (2010) Infrared spectra of OCS-C6H6, OCS-C6H6-He, and OCS-C6H6-Ne van der Waals complexes. J Chem Phys 132(19):194303/1194303/6 doi:10.1063/1.3430571

9 Molecules with Seven to Nine Carbon Atoms

685

786 CAS RN: 90-02-8 MGD RN: 341468 MW augmented by QC calculations

2-Hydroxybenzaldehyde Salicylaldehyde C 7H 6O 2 Cs O

Distances C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–C(6) C(5)–C(6) C(4)–C(5) C(1)–C(7) C(7)=O(2) C(2)–O(1) C(7)–H O(1)–H(1) O(2)...H(1) O(1)...O(2) C(3)–H C(4)–H C(5)–H C(6)–H

rs [Å] a 1.393(6) 1.415(31) 1.392(3) 1.387(5) 1.390(2) 1.399(5) 1.478(5) 1.231(3) 1.332(24) 1.103(2) 0.981(2) 1.777(4) 2.641(4) 1.083(1) 1.084(2) 1.081(1) 1.088(1)

r see [Å] a 1.4073(10) 1.3926(18) 1.3847(13) 1.4019(14) 1.3806(9) 1.4005(14) 1.4546(12) 1.2239(7) 1.3401(13) 1.1006(7) 0.9742(5) 1.7717(5) 2.6357(5) 1.0820(5) 1.0820(5) 1.0805(4) 1.0837(6)

Bond angles C(6)–C(1)–C(2) C(1)–C(6)–C(5) C(1)–C(2)–C(3) C(6)–C(5)–C(4) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–C(7) C(7)–C(1)–C(6) C(1)–C(7)=O(2) C(1)–C(7)–H O(2)=C(7)–H C(2)–O(1)–H(1) C(1)–C(2)–O(1) O(1)–C(2)–C(3) C(2)–C(3)–H C(4)–C(3)–H C(3)–C(4)–H C(5)–C(4)–H C(6)–C(5)–H C(4)–C(5)–H C(1)–C(6)–H C(5)–C(6)–H O(1)–H(1)…O(2)

θs [deg] a

θ see [deg] a

122.2(14) 119.9(2) 117.9(17) 119.0(1) 119.7(5) 121.4(1) 119.0(14) 118.8(2) 124.3(2) 115.9(2) 119.8(2) 107.8(10) 124.2(23) 117.9(6) 118.7(4) 121.6(2) 118.7(2) 119.9(3) 120.7(1) 120.3(1) 119.3(3) 120.8(2) 145.0(1)

H

OH

119.75(14) 120.73(5) 119.44(14) 118.92(3) 119.88(7) 121.29(4) 120.61(15) 119.64(7) 124.29(8) 115.91(7) 119.80(10) 107.91(5) 121.82(16) 118.74(5) 118.80(6) 121.32(5) 119.22(11) 119.50(8) 120.71(6) 120.37(4) 118.70(8) 120.58(9) 145.93(2)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The pure rotational spectrum of the title molecule was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 8 and 18 GHz.

686

9 Molecules with Seven to Nine Carbon Atoms

The main isotopic species and all 13C and 18O isotopic species were measured in natural abundance, whereas the deuterated species were studied in enriched samples. The ground-state rotational constants were determined for 26 different isotopic species, including singly substitution of each of 15 atoms in molecule. Further measurements of the main isotopic species were performed in region between 8 and 230 GHz in order to study rotational transitions in the five lowest excited vibrational states. This allowed the determination of the ΔBv = Bv ‒ B0 rovibrational corrections, used to calibrate the MP2/cc-pVDZ anharmonic force field, which was then used to determine the semiexperimental equilibrium structure r see . The molecule is stabilized by the OH(1)…O(2) intramolecular hydrogen bond. Dorosh O, Białkowska-Jaworska E, Kisiel Z, Pszczółkowski L, Kańska M, Krygowski TM, Mäder H (2017) The complete molecular geometry and electric dipole moment of salicylaldehyde from rotational spectroscopy. J Mol Spectrosc 335(5):3-12

787 CAS RN: 69-72-7 MGD RN: 210200 MW augmented by ab initio calculations

2-Hydroxybenzoic acid Salicylic acid C 7H 6O 3 Cs O

Bonds C(1)–C(2) C(1)–C(6) C(5)–C(6) C(2)–C(3) C(3)–C(4) C(1)–C(7) C(2)–O(8) C(7)=O(9) C(7)–O(10) O(8)–H(1) O(10)–H(2) C(3)–H C(4)–H C(5)–H C(6)–H

r0 [Å] a 1.415 1.410 1.390 1.404 1.392 1.473 1.350 1.227 1.348 0.977 0.969 1.086 1.087 1.086 1.085

Bond angles C(7)–C(1)–C(2) O(9)=C(7)–C(1) C(2)–C(1)–C(6) C(5)–C(6)–C(1) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(1)–C(2)–O(8) C(1)–C(7)–O(10) C(2)–O(8)–H(1) C(7)–O(10)–H(2) C(2)–C(3)–H C(3)–C(4)–H C(4)–C(5)–H C(5)–C(6)–H

θ0 [deg] b 117.1(1) 123.1(1) 119.8 a 120.5 a 119.1 a 120.5 a 123.5 a 114.1 a 106.7 a 105.8 a 118.0 a 119.4 a 120.4 a 120.7 a

Copyright 2009 with permission from Elsevier.

a

Assumed at the value from MP2/6-311++G(d,p) calculation.

OH

OH

9 Molecules with Seven to Nine Carbon Atoms b

687

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the title compound were recorded by a free-jet millimeter-wave spectrometer in the frequency region between 60 and 79 GHz. Only one conformer, stabilized by an intramolecular hydrogen bond between the phenolic hydrogen and the carbonyl oxygen, was detected. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main, two D and D2); the remaining structural parameters were assumed at the values from ab initio calculations (see above). According to calculations, this conformer is significantly more stable than the two other ones differing in the orientations of the carboxylic and hydroxylic groups; its amount was predicted to be more than 97 % at 403 K. Evangelisti L, Tang S, Velino B, Caminati W (2009) Microwave spectrum of salicylic acid. J Mol Struct 921(13):285-288

788 CAS RN: 22917-01-7 MGD RN: 155647 MW

Benzene – trifluoromethane (1/1) C7H7F3 C3v F

Distances Rcm b Rcm c

r0 [Å] a 3.4683(1) 3.4639(1)

rs [Å] a 3.4381(15) 3.4343(15)

F

F

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. Rcm for complex with HCF3. c Rcm for complex with DCF3. b

The rotational spectrum of the binary complex of benzene with deuterated trifluoromethane was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 7 and 14 GHz. The partial r0 structures of the complexes with HCF3 and DCF3 units were determined from the ground-state rotational constants of six isotopic species (main, D, two 13C and two 13C/D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The partial rs structure was also determined. The complex is formed by a weak hydrogen bond with the π-electron system of the benzene ring. A shortening of the distance between the two subunits of the complex upon H → D substitution (Ubbelohde effect) was determined to be 0.0044(2) Å. Gou Q, Feng G, Evangelisti L, Loru D, Alonso JL, López JC, Caminati W (2013) Ubbelohde effect within weak C-H⋅⋅⋅π hydrogen bonds: the rotational spectrum of benzene-DCF3. J Phys Chem A 117(50):13531-13534

789 CAS RN: 1551489-13-4 MGD RN: 417640 MW augmented by ab initio calculations

(Trifluoromethoxy)benzene – water (1/1) Trifluoroanisole – water (1/1) C7H7F3O2 C1 O

F

O

F

Distances H(2)…O(1)

a

r0 [Å] 2.574(5)

F

H

H

688

9 Molecules with Seven to Nine Carbon Atoms

O(2)…H(1)

2.294(5) b

Angles C(2)-H(2)…O(1) O(2)…H(1)-O(1)

θ0 [deg] a

Dihedral angle O(1)…C(2)-H(2)…C(1)

τ0 [deg] a

130.8(5) 140.5(5) b

-36.6(3)

Reprinted with permission. Copyright 2014 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectra of the binary complex of trifluoroanisole with water were recorded in a supersonic jet by a pulsed-jet FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 18O); the remaining structural parameters were fixed at the MP2/6-311++G(d,p) values. Gou Q, Spada L, Vallejo-López M, Kang L, Novick SE, Caminati W (2014) Fluorination effects on the shapes of complexes of water with ethers: a rotational study of trifluoroanisole-water. J Phys Chem A 118(6):1047-1051

790 CAS RN: 790665-58-6 MGD RN: 443227 MW supported by ab initio calculations

Pyridine – ethyne (1/1) Pyridine – acetylene (1/1) C 7H 7N Cs H

Distances Rcm b N…H c

r0 [Å] a 5.1271(21) 2.316(28)

Angles

θ0 [deg] a

d

ϕ φe

C

C

H

N

23.2(2) -23.2(21)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit. Distance between centers of mass of two monomer subunits. c Hydrogen bond. d Angle between Rcm and the C2 axis of the pyridine subunit. e Angle between Rcm and the C∞ axis of the acetylene subunit. b

The rotational spectra of the binary complex of pyridine with acetylene were recorded in a supersonic jet by pulsed-nozzle FTMW spectrometers in the frequency region between 4.3 and 10.7 GHz. The partial r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, four 13C, two D and D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation.

9 Molecules with Seven to Nine Carbon Atoms

689

Mackenzie RB, Dewberry CT, Coulston E, Cole GC, Legon AC, Tew DP, Leopold KR (2015) Intramolecular competition between n-pair and π-pair hydrogen bonding: Microwave spectrum and internal dynamics of the pyridine-acetylene hydrogen-bonded complex. J Chem Phys 143(10):104309/1-104309/10 [http://dx.doi.org/10.1063/1.4929997]

791 CAS RN: 103-70-8 MGD RN: 145248 GED augmented by ab initio computations

Bonds C(1)–C(2) C(6)–C(1) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C–H N–H C(1)–N(7) N(7)–C(8) C(8)=O Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(6)–C(1)–N(7) C(1)–N(7)–C(8) N(7)–C(8)=O C–C–H C(8)–N(7)–H O(9)–C(8)–H C(3)–C(4)–C(5) e C(4)–C(5)–C(6) e C(5)–C(6)–C(1) e Dihedral angles C(2)–C(1)–N(7)–C(8) H–N(7)–C(8)=O C(1)–N(7)–C(8)=O

N-Phenylformamide Formanilide C7H7NO Cs (syn) C1 (anti)

rh1 [Å] a,b syn anti 1.403(1) 1 1.401(1) 1 1 1.402(1) 1.402(1) 1 1 1.397(1) 1.396(1) 1 1 1.396(1) 1.397(1) 1 1 1.393(1) 1.395(1) 1 1 1.398(1) 1.397(1) 1 c,2 1.086(4) 1.086(4) c,2 2 1.012(4) 1.015(4) 2 1 1.409(1) 1.409(1) 1 3 1.367(1) 1.369(1) 3 4 1.209(2) 1.208(2) 4

syn

θh1 [deg] a,b

syn 119.6(2) 5 119.1(2) 5 121.1(2) 5 118.8(2) 6 129.3(3) 7 127.2(3) 7 120.1 c,d 115.2 d 122.6 d 119.8(9) 119.4(12) 120.9(9)

syn 0.0 d 180.0 d 0.0 d

anti 119.4(2) 5 119.8(2) 5 120.5(2) 5 120.7(2) 6 126.0(3) 7 124.5(3) 7 119.8 c,d 115.2 d 123.5 d 119.9(9) 119.6(12) 120.7(9)

anti

τh1 [deg]

anti 36.2 d 7.3 d 178.4 d

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from MP2/cc-pVTZ computations. c Average value. d Assumed at the value computed at the level of theory as indicated above. e Dependent parameter. b

690

9 Molecules with Seven to Nine Carbon Atoms

The GED experiment was carried out at Tnozzle = 410 K. The title compound was found to exist as a mixture of syn (58(5)%) and anti (42(5)%) conformers, characterized by the synperiplanar and antiperiplanar C(2)–C(1)– N(7)–C(8) torsional angles, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/cc-pVTZ computation. Marochkin II, Dorofeeva OV (2013) Molecular structure and relative stability of trans and cis isomers of formanilide: Gas-phase electron diffraction and quantum chemical studies. Struct Chem 24 (1):233-242

792 CAS RN: 622-31-1 MGD RN: 142603 GED combined with MW and augmented by QC computations

(E)-Benzaldehyde oxime C7H7NO Cs OH

N

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(1)–C(7) C(7)=N(8) N(8)–O(9) C(2)–H C(3)–H C(4)–H C(5)–H C(6)–H C(7)–H O(9)–H

ra [Å] a 1.401(1) 1.396 b 1.400 b 1.397 b 1.396 b 1.405 b 1.467(6) 1.296(5) 1.399(6) 1.073(5) 1.074 c 1.074 c 1.074 c 1.075 c 1.079 c 0.952(18)

rz [Å] a 1.401(1) 1.396 b 1.400 b 1.397 b 1.395 b 1.405 b 1.468(6) 1.290(5) 1.397(6) 1.071(5) 1.072 c 1.071 c 1.072 c 1.074 c 1.074 c 0.934(18)

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(2)–C(1)–C(7) C(6)–C(1)–C(7) C(1)–C(7)=N(8) C(7)=N(8)–O(9) C(1)–C(2)–H C(2)–C(3)–H C(3)–C(4)–H C(4)–C(5)–H C(5)–C(6)–H C(1)–C(7)–H N(8)–O(9)–H

θa [deg] a

θz [deg] a

119.7(2) 120.0 d 119.7 e 121.0 e 119.0 e 120.6 d 123.6(7) 116.7 e 119.3(8) 110.5(8) 119.4 f 119.6 f 120.1 f 120.2 f 120.1 f 119.2 f 101.3(45)

119.5(1) 119.7 d 120.9 e 119.3 e 120.2 e 120.4 d 123.5(5) 117.0 e 119.4(6) 111.1(8) 119.4 f 119.6 f 120.1 f 120.2 f 120.1 f 119.2 f 103.7(48)

Copyright 2010 with permission from Elsevier [a].

9 Molecules with Seven to Nine Carbon Atoms

691

a

Parenthesized uncertainties in units of the last significant digits are 3σ values. Difference to the C(1)–C(2) bond length was constrained to the value from MP2/6-31G(d,p) computation. c Difference to the C(2)–H bond length was constrained to the value from computation as indicated above. d Difference to the C(6)–C(1)–C(2) bond angle was constrained to the value from computation as indicated above. e Dependent parameter. f Adopted from computation as indicated above. b

The GED experiment was carried out at Tnozzle of 357…366 K. Two structural data sets were obtained. The ra structure was determined from the GED data alone using dynamic model of the large amplitude torsional motion around the C(1)−C(7) bond. The barrier to internal rotation was determined to be very high (74(28) kJ mol-1). Moreover, the rz structure was determined from the GED data combined with MW ground-state rotational constants from Ref. [b] using small-amplitude model. Vibrational corrections to the experimental internuclear distances, ∆rz = ra − rz, were calculated using harmonic force constants from B3LYP/6-31(d,p) computation as well as anharmonic Morse constants, which were assumed to be 2.0 and 0.0 Å-1 for the bonded and non-bonded atom pairs, respectively. Vibrational corrections to the experimental rotational constants, ∆Bz = B0 − Bz, were calculated using scaled harmonic force constants. Both the ra and rz structure corresponds to planar configuration of the molecule with the torsional angle ϕ = C(2)–C(1)–C(7)=N = 0°, whereas ϕa = 23(7)° if the large amplitude effects are neglected. a. Kuze N, Sakaizumi T, Ohashi O, Yokouchi Y, Iijima K (2010) Molecular structure of (E)-benzaldehyde oxime from gas-phase electron diffraction, quantum-chemical calculations and microwave spectroscopy. J Mol Struct 978 (1-3):195-200 b. Kuze N, Sato M, Maue K, Usami T, Sakaizumi T, Ohashi O, Iijima K (1999) Microwave spectrum and molecular conformation of (E)-benzaldehyde oxime. J. Mol. Spectrosc 196:283-289

793 CAS RN: 55-21-0 MGD RN: 144006 GED augmented by QC computations

Benzamide C7H7NO C1

O

NH2

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–C(7) C(7)–N(9) C(7)=O(8) C–H N–H

re [Å] a,b 1.394(1) 1 1.388(1) 1 1.392(1) 1 1.391(1) 1 1.390(1) 1 1.395(1) 1 1.502(4) 1.368(1) 1 1.225(2) 1.085(4) 2,c 1.008(4) 2,c

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–C(7) C(1)–C(7)=O(8) C(1)–C(7)–N(9)

θe [deg] a,b 120.1(1) 3 120.1(1) 3 119.8(1) 3 117.4(1) 3 120.9(9) 116.7(9)

692

9 Molecules with Seven to Nine Carbon Atoms

C(1)–C(2)–H C(2)–C(3)–H C(5)–C(4)–H C(4)–C(5)–H C(5)–C(6)–H C(7)–N(9)–Hʹ C(7)–N(9)–Hʹʹ C(6)–C(1)–C(2) C(4)–C(5)–C(6) C(5)–C(6)–C(1) O(8)=C(7)–N(9)

118.4 d 119.9 d 120.0 d 120.1 d 119.6 d 115.2 d 119.0 d 119.8 e 120.2 e 119.9 e 122.4 e

Dihedral angles C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(2)–C(1)–C(7)=O(8) C(6)–C(1)–C(7)–N(9)

τe [deg] a,b 0.7 d 0.2 d 18.4(27) 4 17.7(27) 4

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from MP2/cc-pVTZ computation. c Average value. d Assumed at the value from computation as indicated above. e Dependent parameter. b

The GED experiment was carried out at Tnozzle = 430 K. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the MP2/cc-pVTZ quadratic and cubic force fields taking into account non-linear kinematic effects. Kolesnikova IN, Hargittai I, Shishkov IF (2015) Equilibrium molecular structure of benzamide from gas-phase electron diffraction and theoretical calculations. Struct Chem 26 (5-6):1473-1479

794 CAS RN: 65-45-2 MGD RN: 513559 GED augmented by QC computations

Distances C(1)–C(2) C(8)=O(9) C(8)–N C(2)–O(7) C(3)–C(4) C(5)–C(6) C(1)–C(6) C(2)–C(3) C(4)–C(5) C(1)–C(8) C–H O(9)...H(3) O(7)–H(3) N–H

rh1 [Å] a 1.424(2) b 1.232(6) b 1.357(5) b 1.337(5) c 1.401(5) d 1.401(4) d 1.417(4) d 1.413(5) d 1.412(4) d 1.496(4) d 1.082(14) e,b 1.607(82) 1.038(45) f 1.066(1) e,b

2-Hydroxybenzamide Salicylamide C7H7NO2 C1

9 Molecules with Seven to Nine Carbon Atoms

Bond angles C(1)–C(8)=O(9) C(1)–C(8)–N C(1)–C(2)–O(7) C(6)–C(1)–C(8) C(2)–C(1)–C(6) C(1)–C(2)–C(3) C(1)–C(6)–C(5) C–C–H C–N–H(1) C–N–H(2) C(2)–O(7)–H(3)

θh1 [deg] a

Dihedral angles C(2)–C(1)–C(8)=O(9) C(1)–C(8)–N–H(1) C(1)–C(2)–O(7)–H(3)

τh1 [deg] a

693

120.1(9) b 118.8(12) b 123.5(15) b 122.7(10) b 119.1(3) g 119.3(3) 121.2(3) g 120.0 h 110.9(9) 119.2(5) 105.6(10)

-15(5) b, i -180(1) b,j -170(4) b,k

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Independent parameter. c Flexibly restrained to C(8)–N. d Flexibly restrained to C(1)–C(2). e Average value. f Flexibly restrained to N–H. g Flexibly restrained to C(1)–C(2)–C(3). h Assumed at the value from MP2/6-311+G(d,p) calculation. i 0° when the C(8)=O(9) bond is eclipsing the C(2)–C(1) bond. j 0° when the N–H(2) bond is eclipsing the C(1)–C(8) bond. k 180° when the O(7)–H(3) bond is eclipsing the C(1)–C(2) bond. b

The GED experiment was carried out at Tnozzle ≈ 420 K. According to prediction of MP2/6-311+G(d,p) computations, the title molecules exist at this temperature as a single conformer stabilized by the C=O…H−O hydrogen bond. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from HF/6-311+G(d,p) computation. Aarset K, Page EM, Rice DA (2013) Hydrogen bonding in the gas-phase: The molecular structures of 2hydroxybenzamide (C7H7NO2) and 2-methoxybenzamide (C8H9NO2), obtained by gas-phase electron diffraction and theoretical calculations. J Phys Chem A 117 (14):3034-3040

795 CAS RN: 100-17-4 MGD RN: 548338 MW supported by DFT calculations Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4)

1-Methoxy-4-nitrobenzene 4-Nitroanisole C7H7NO3 C1

rs [Å] a 1.474(17) 1.326(9) 1.406(7)

[Å] a r (1) m 1.386(6) 1.400(7) 1.398(4)

694

9 Molecules with Seven to Nine Carbon Atoms

C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–N N=O(12) N=O(13) O(12)...O(13) C(4)–O(14) O(14)–C(15)

1.408(6) 1.353(9) 1.344(18)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(6)–C(1)–C(2) C(2)–C(1)–N C(6)–C(1)–N C(1)–N=O(12) C(1)–N=O(13) O(12)=N=O(13) C(3)–C(4)–O(14) C(4)–O(14)–C(15) C(5)–C(4)–O(14)

θs [deg] a

118.42(53) 119.50(24) 120.05(29) 120.10(54) 118.87(88) 120.30(48)

1.402(4) 1.394(8) 1.385(6) 1.475(3) 1.220(3) 1.230(3) 2.167(3) 1.356(2) 1.414(4)

O CH3 O N O

θ (1) [deg] a m

118.94(31) 119.29(25) 120.57(22) 120.16(23) 118.30(36) 122.74(42) 118.25(38) 119.01(40) 117.78(25) 117.90(24) 124.31(10) 124.65(30) 118.07(30) 114.79(31)

Reproduced with permission of AIP Publishing.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of 4-nitroanisole was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8 GHz. In addition to the main isotopic species, all 13C, 15N and 18O singly substituted species were measured in natural abundance. Because the Kraitchman analysis of the 15 N and 18O isotopic species delivered imaginary Cartesian coordinates only the substitution structure rs of the ring skeleton was determined; a non-planar configuration was favored according to the non-zero experimental was obtained for the heavy-atom skeleton. inertial defect. Moreover, the mass-dependent structure r (1) m Graneek JB, Pérez C, Schnell M (2017) Structural determination and population transfer of 4nitroanisole by broadband microwave spectroscopy and tailored microwave pulses. J Chem Phys 147(15):154306/1-154306/10 https://doi.org/10.1063/1.4991902

796 CAS RN: 940-12-5 MGD RN: 457127 MW augmented by DFT calculations

1-(Methylsulfinyl)-4-nitrobenzene Methyl p-nitrophenyl sulfoxide C7H7NO3S C1 O

O N

Angles O(9)=S(8)–C(2) O(9)=S(8)–C(10)

θ0 [deg] a

Dihedral angle

τ0 [deg] a

93.0 98.1

O

S CH3

9 Molecules with Seven to Nine Carbon Atoms

O(9)=S(8)–C(2)–C(6)

695

2.5

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Uncertainties were not given in the original paper.

The rotational spectrum of the title compound was recorded using a Stark- and pulse-modulated free-jet absorption millimeter-wave spectrometer in the frequency range between 60 and 78.3 GHz. The partial r0 structure was determined from the experimental ground-state rotational constants of one isotopic species; the remaining structural parameters were fixed at the B3LYP/6-31G** values. Celebre G, DeLuca G, DiPietro ME, Giuliano BM, Melandri S, Cinacchi G (2015) Detection of significant aprotic solvent effects on the conformational distribution of methyl 4-nitrophenyl sulfoxide: from gas-phase rotational to liquid-crystal NMR spectroscopy. ChemPhysChem 16(11):2327-2337

797 CAS RN: 30384-53-3 MGD RN: 415148 GED combined with MS and augmented by QC computations

2-Nitrobenzenesulfonic acid methyl ester Methyl 2-nitrobenzenesulfonate C7H7NO5S C1 (all conformers) O

O S O

Bonds C–H c C–H e C–C C(1)–S C(2)–N S=O(3) S=O(4) S–O(5) N=O(1) N=O(2) O(5)–C(7)

rh1 [Å] a,b 1.080(8) d,1 1.085(8) d,1 1.400(5) d 1.781(6) 1.469(15) 1.426(5) 2 1.428(5) 2 1.588(5) 2 1.235(10) 3 1.236(10) 3 1.487(16)

Bond angles N–C(2)–C(1) C(2)–C(1)–C(6) C(1)–C(2)–C(3) O(1)=N–C(2) C(1)–S–O(5) C(1)–S=O(3) C(1)–S=O(4) O(5)–S=O(4) S–C(1)–C(2) S–O(5)–C(7) O(1)=N=O(2)

θh1 [deg] b,f

Dihedral angles O(1)=N–C(2)–C(1)

τh1 [deg] f

123.6(20) 117.7(3) 4 121.2(3) 4 117.6(7) 102.5(31) 108.6(14) 5 111.6(14) 5 111.4(10) 123.3(15) 113.8(21) 125.2(13)

46.5 g

O N O

CH3

696

C(2)–C(1)–S–O(5) S–C(1)–C(2)–C(3) C(1)–S–O(5)–C(7) Hʹ–C–O–S

9 Molecules with Seven to Nine Carbon Atoms

-96(7) -170(5) 139(9) -172.8 g

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the computed values. c In the phenyl ring. d Average value. e In the methyl group. f Parenthesized uncertainties in units of the last significant digit are 3σ values. g Fixed at the computed value. Six conformers, characterized by different positions of the nitro and sulfonic ester groups relative to the benzene ring, were predicted by the MP2 and B3LYP methods in conjunction with cc-pVTZ basis set. The GED experiment was carried out at Teffusion cell = 380(5) K. The best fit to the experimental intensities was obtained for a mixture of four lowest energy conformers in the ratio predicted by B3LYP, namely, I : II : III : IV = 51 : 20 : 19 : 10 (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from B3LYP computation. Differences between corresponding structural parameters of the conformers, except for torsional angles, were adopted from the computation. Structural parameters were presented for the predominant conformer (I). Giricheva NI, Fedorov MS, Ivanov SN, Girichev GV (2015) The difference between gas-phase and crystal structures of ortho-nitromethylbenzenesulfonate. Conformation variety study of free molecules by electron diffraction and quantum chemistry. J Mol Struct 1085:191-197

798 CAS RN: 6214-20-6 MGD RN: 344563 GED combined with MS and augmented by DFT computations

4-Nitrobenzenesulfonic acid methyl ester Methyl 4-nitrobenzenesulfonate C7H7NO5S C1 (I) Cs (II) O

Bonds C–H c C–H e C–C C(1)–S S–O(1) S=O(2) S=O(3) N=O(4) O(1)–C(7) C(4)–N

rh1 [Å] a,b 1.062(6) d,1 1.069(6) d,1 1.395(4) d 1.786(5) 1.607(4) 2 1.431(4) 2 1.439(4) 2 1.228(3) 1.445(6) 3 1.482(6) 3

Bond angles C(2)–C(1)–C(6) C(3)–C(4)–C(5) C(1)–S–O(1) C(1)–S=O(2)

θh1 [deg] a,b 121.8(5) 4 122.5(1) 4 105.4(22) 108.2(8) 5

O S O

O N O

CH3

9 Molecules with Seven to Nine Carbon Atoms

C–S=O(3) C(7)–O(1)–S S–C(1)–C(2) O(1)–S=O(2) O(4)–N–C(4)

107.9(8) 5 119.3(12) 119.3(9) 103.3(8) 117.1(4)

Dihedral angles O(1)–S–C(1)–C(2) C(7)–O(1)–S–C(1)

τh1 [deg] a

697

-73(13) -74(8)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit were not specified. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/cc-pVTZ calculation. c In the phenyl ring. d Average value. e In the methyl group. b

The GED experiment was carried out at Tnozzle = 376(5) K. Two conformers, I and II, characterized by the synclinal and antiperiplanar C(7)–O(1)–S–C(1) torsional angles, were found to be present in amounts of 52(7) and 48(7)%, respectively. Nitrobenzene group was assumed to be planar (C2v local symmetry). Differences between corresponding parameters of the conformers, except for torsional angles, were assumed at the values from B3LYP/cc-pVTZ calculation. The barriers to internal rotation around the C–N, C–S, S–O and O–C bonds were estimated to be higher than the thermal energy RT. Structural parameters were presented for the conformer I. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from computation at the level of theory as indicated above. Giricheva NI, Fedorov MS, Girichev GV (2015) Conformations of methylbenzenesulfonate and its substituted derivatives: gas-phase electron diffraction versus vibrational spectroscopy. Struct Chem 26 (5-6):1543-1553

799 CAS RN: 89-99-6 MGD RN: 375331 MW augmented by ab initio calculations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(2)–F C(3)–H C(4)–H C(5)–H C(6)–H C(1)–C(7) C(7)–N C(7)–H(1) C(7)–H(2)

2-Fluorobenzenemethanamine o-Fluorobenzylamine C7H8FN C1 NH2

r0 [Å] a 1.384(5) 1.382(2) 1.391(3) 1.411(3) 1.400(4) 1.365(5) 1.085 b 1.086 b 1.086 b 1.088 b 1.527(4) 1.4693(8) 1.094 b 1.095 b

F

698

9 Molecules with Seven to Nine Carbon Atoms

N–H(3) N–H(4)

1.016 b 1.015 b

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(1)–C(2)–F C(2)–C(3)–H C(3)–C(4)–H C(4)–C(5)–H C(5)–C(6)–H C(2)–C(1)–C(7) C(1)–C(7)–N C(1)–C(7)–H(1) C(1)–C(7)–H(2) C(7)–N–H(3) C(7)–N–H(4)

θ0 [deg] a

Dihedral angles C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6) C(3)…C(1)–C(2)–F C(4)…C(2)–C(3)–H C(5)…C(3)–C(4)–H C(3)–C(4)–C(5)–H C(4)–C(5)–C(6)–H C(6)…C(2)–C(1)–C(7) C(6)–C(1)–C(7)–N H(1)–C(7)–C(1)…N H(2)–C(7)–C(1)…H(1) H(3)–N–C(7)–C(1) H(4)–N–C(7)–C(1)

τ0 [deg] -0.96 b 0.90 b -0.82 b 179.39 b 180.53 b 179.20 b 179.75 b 179.88 b 177.40 b 108.97 b 121.60 b 116.95 b -52.80 b 64.12 b

123.55 b 118.39 b 119.70(8) 119.82 b 117.95 b 119.59 b 119.57 b 120.16 b 119.94 b 120.81 b 115.72(5) 109.84 b 108.50 b 109.67 b 109.75 b

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit. Fixed to the MP2/6-311++G** value.

The rotational spectrum of the title compound was recorded by a pulsed-jet FTMW spectrometer in the frequency range between 6 and 18.5 GHz. The two lowest energy conformers with an energy difference of ≈ 5kJ mol-1, predicted by MP2/6-311++G** calculations, were detected in the spectrum. The most stable conformer is characterized by the anticlinal N–C–C–C and antiperiplanar lp–N–C–C torsional angles (lp is electron lone pair of the N atom); in the second conformer, these angles are synperiplanar and synclinal, respectively. The partial r0 structure of the most stable conformer was determined from the ground-state rotational constants of nine isotopic species (main, seven 13C and 15N); the remaining structural parameters were fixed to the values from MP2/6-311++G** calculations. This conformer exhibits a tunnelling motion between two equivalent positions of the amino group. Calabrese C, Maris A, Evangelisti L, Caminati W, Melandri S (2013) Fluorine substitution effects on flexibility and tunneling pathways: the rotational spectrum of 2-fluorobenzylamine. ChemPhysChem 14(9):1943-1950

9 Molecules with Seven to Nine Carbon Atoms

800 CAS RN: 90-05-1 MGD RN: 211686 GED augmented by QC computations

699

2-Methoxyphenol 2-Hydroxyanisole C 7H 8O 2 Cs (anti-syn) O

CH3

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(1)–O(7) C(2)–O(8) C(9)–O(7) O(8)–H C–H

rh1[Å] a,b 1.411(2) 1 1.390(2) 1 1.399(2) 1 1.391(2) 1 1.402(2) 1 1.392(2) 1 1.378(4) 2 1.368(4) 2 1.424(4) 2 1.001(6) 3 1.119(6) 3,c

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–O(7) C(1)–C(2)–O(8) C(1)–O(7)–C(9) C(2)–O(8)–H C(4)–C(5)–C(6) C(1)–C(6)–C(5) C(2)–C(1)–C(6) C–C–H O–C–H(1) O–C–H(2)

θh1 [deg]a,b

Dihedral angles C(1)–O(7)−C(9)–H(2) C(2)–C(1)−O(7)–C(9) C(1)–C(2)−O(8)–H

τh1 [deg]

OH

119.9(2) 4 120.2(2) 4 120.3(2) 4 113.8(5) 5 120.0(5) 5 118.2(5) 5 107.6 d 119.7(8) e 120.4(11) e 119.6(8) e 118.6-120.5 d 106.2 d 111.3 d

61.1 d 180.0 d 0.0 d

Copyright 2009 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from B3LYP/cc-pVTZ computation. c Average value. d Assumed at the value from computation as indicated above. e Dependent parameter. b

According to predictions of ab initio computations (MP2 and MP4 with different basis sets), the anti-syn conformer (Cs symmetry), characterized by the antiperiplanar and synperiplanar positions of the methoxy and hydroxyl groups relative to the C(1)–C(2) bond, respectively, is essentially lower in energy than the anti-anti and anti-gauche conformers (by ca. 4.5 and 5 kcal mol-1, respectively) due to formation of the hydrogen bond between phenolic hydrogen and methoxy oxygen. The amount of the anti-syn conformer was predicted to be 99 %, being confirmed by the GED analysis. The GED experiment was carried out at Tnozzle = 351 K.

700

9 Molecules with Seven to Nine Carbon Atoms

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Dorofeeva OV, Shishkov IF, Karasev NM, Vilkov LV, Oberhammer H (2009) Molecular structures of 2methoxyphenol and 1,2-dimethoxybenzene as studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 933 (1-3):132-141

801 CAS RN: 153440-95-0 MGD RN: 417455 MW supported by QC calculations

Benzoic acid – water (1/1) C 7H 8O 3 C1 O

OH

a

Distance Rcm b

r0 [Å] 4.81

Angle

θ0 [deg] a

α

c

O H

H

4.9

Reproduced with permission from the PCCP Owner Societies.

a

Uncertainty was not given in the original paper. Distance between the centers of mass of the monomer subunits. c Angle between the principle axis a of the benzoic acid subunit and the intermolecular bonding axis. b

The rotational spectra of the binary complex of benzoic acid with water were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 14 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Schnitzler EG, Jäger W (2014) The benzoic acid-water complex: a potential atmospheric nucleation precursor studied using microwave spectroscopy and ab initio calculations. Phys Chem Chem Phys 16(6):2305-2314

802 CAS RN: 104-15-4 MGD RN: 344169 GED combined with MS augmented by QC computations

Bonds C(7)–H b C–H C(1)–C(2) C–C C(4)–C(7) C–S

rh1 [Å] a 1.108(5) 1.099(5) b,c 1.401(3) 1.403(3) b,d 1.517(3) d 1.765(5)

4-Methylbenzenesulfonic acid C7H8O3S C1

9 Molecules with Seven to Nine Carbon Atoms

S–O(1) S=O O–H

1.618(4) 1.433(4) b,e 0.968 f

Bond angles C(1)–C(2)–C(3) C(2)–C(1)–C(6) C(3)–C(4)–C(5) S–C(1)–C(2) O(1)–S–C(1) O(2)=S–C(1) O(2)=S–O(1) H–O(1)–S C(4)–C(7)–H(2)

θh1 [deg] a

Dihedral angles S–C(1)–C(2)–C(3) O(1)–S–C(1)–C(2) H–O(1)–S=O(2) C(3)–C(4)–C(7)–H(2)

τh1 [deg] a

701

118.8(3) 122.2(3) g 118.2(3) g 120.0(17) 102.8(23) 109.6(10) 106.9(14) 107.5 f 106.5(26)

179(9) -101(10) -14.3 f 87(88)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Average value. c Difference to C(7)–H was assumed at the value from B3LYP/cc-pVTZ computation. d Difference to C(2)–C(1) was assumed at the value from calculation as indicated above. e Difference to S–O(1) was assumed at the value from calculation as indicated above. f Assumed as above. g Difference to C(1)–C(2)–C(3) was assumed at the value from calculation as indicated above. The GED experiment was carried out at Teffusion cell = 417(10) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Giricheva NI, Girichev GV, Fedorov MS, Ivanov SN (2013) Substituent effect on geometric and electronic structure of benzenesulfonic acid: Gas-phase electron diffraction and quantum chemical studies of 4CH3C6H4SO3H and 3-NO2C6H4SO3H molecules. Struct Chem 24 (3):807-818

803 CAS RN: 14990-01-3 MGD RN: 361928 GED augmented by ab initio computations

Bonds P–C P–H C(1)–C(7) C(1)–C(3) C(3)–C(5)

(Phenylmethyl)phosphine Benzylphosphine C7H9P Cs (I) C1 (II) PH2

Cs 1.881(2) 1.430(8) c 1.508(4) c 1.387(6) c 1.383(6) c

rh1 [Å] a C1 1.883(2) b 1.430(8) c 1.512(4) c 1.386(6) c 1.383(6) c

702

9 Molecules with Seven to Nine Carbon Atoms

1.425(5) c

C(5)–C(6) Bond angles

Cs 116.8(6) 119.7(2) d 120.6(5) 121.3(5) e 117.8(4) d 121.2(5) d 96.0(10) e 94.0(10) e

P–C–C C(7)–C(1)–C(3) C(2)–C(1)–C(3) C(4)–C(6)–C(5) C(3)–C(5)–C(6) C(1)–C(3)–C(5) C–P–H H–P–H Dihedral angles

Cs 0.0 0.0

C–C–P…X g C–C–C–P h

1.425(5) c

θh1 [deg] a

C1 111.8(5) b 119.7(2) d 120.6(5) 121.3(5) e 117.8(4) d 121.2(5) d 96.0(10) e,f 94.0(10) e

τh1 [deg] a

C1 -118.5(15) e -5.6(15) e

Reprinted with permission. Copyright 2009 American Chemical Society.

I

II

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Difference to corresponding parameter of the Cs conformer was restrained to the value from MP2/6-311++G** computation. c Derived from the refined average value of r(P–H) and r(C–C) and the differences between these distances restrained to the values from computation as indicated above. d Dependent parameter. e Restrained to the value from computation as indicated above. f Average value. g X is the bisector of the H–P–H angle. h Deviation from 90°. b

MP2 computations predicted existence of two conformers, one with the ±synclinal C–C–P–H dihedral angles and the other one with the antiperiplanar and synclinal C–C–P–H dihedral angles. The GED experiment was carried out at 293 K. The ratio of the conformers was determined to be Cs : C1 = 33(11) : 67(11) (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from MP2/6-311++G** computation. Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612

804 CAS RN: 930-51-8

Ethynylcyclopentane Cyclopentylacetylene

9 Molecules with Seven to Nine Carbon Atoms

703

C7H10 Cs (equatorial) Cs (axial)

MGD RN: 117380 MW augmented by QC calculations

equatorial r0 [Å] a 1.211(3) 1.461(3) 1.542(3) 1.541(3) 1.556(3) 1.064(2) 1.099(2) 1.096(2) 1.093(2) 1.093(2) 1.094(2)

axial r0 [Å] a 1.211(3) 1.467(3) 1.542(3) 1.542(3) 1.555(3) 1.065(2) 1.095(2) 1.093(2) 1.096(2) 1.093(2) 1.093(2)

Bond angles C(1)–C(4)≡C(5) C(2)–C(1)–C(4) C(2)–C(1)–C(2ꞌ) C(1)–C(2)–C(3) C(2)–C(3)–C(3ꞌ) H–C(5)≡C(4) H–C(1)–C(4) H–C(1)–C(2) H(1)–C(2)–C(1) H(1)–C(2)–C(3) H(2)–C(2)–C(1) H(2)–C(2)–C(3) H(1)–C(2)–H(2) H(1)–C(3)–C(2) H(1)–C(3)–C(3ꞌ) H(2)–C(3)–C(2) H(2)–C(3)–C(3ꞌ) H(1)–C(3)–H(2)

θ0 [deg] a

θ0 [deg] a

Dihedral angles C(2)–C(1)–C(2ꞌ)–C(3ꞌ) C(2)–C(3)–C(3ꞌ)–C(2)

τ0 [deg] a

τ0 [deg] a

Bonds C(4)≡C(5) C(1)–C(4) C(1)–C(2) C(2)–C(3) C(3)–C(3ꞌ) C(5)–H C(1)–H C(2)–H(1) C(2)–H(2) C(3)–H(1) C(3)–H(2)

179.4(5) 113.7(5) 102.6(5) 103.7(5) 106.0(5) 179.9(5) 108.9(5) 108.8(5) 108.2(5) 109.1(5) 112.8(5) 114.9(5) 107.9(5) 111.5(5) 112.8(5) 110.1(5) 109.3(5) 107.1(5)

40.8(5) 0.0(5)

C

C

H

equatorial

179.9(5) 111.5(5) 102.1(5) 103.7(5) 105.9(5) 179.6(5) 109.2(5) 111.2(5) 112.9(5) 114.9(5) 108.1(5) 108.6(5) 108.3(5) 110.0(5) 109.5(5) 111.4(5) 112.7(5) 107.4(5)

axial

41.6(5) 0.0(5)

Copyright 2013 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

The envelope-equatorial and envelope-axial conformers were identified in the temperature-dependent Raman vibrational spectra. The enthalpy difference between the more stable equatorial conformer and the axial one was estimated to be 1.12(11) kJ mol-1 by temperature-dependent IR vibrational spectroscopy. The percentage of the axial conformer was estimated to be 39(2) % (at ambient temperature). The r0 structural parameters of each conformers were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the previously published experimental ground-state rotational constants of one isotopic species.

704

9 Molecules with Seven to Nine Carbon Atoms

Durig JR, Klaassen JJ, Deodhar BS, Darkhalil ID, Herrebout WA, Dom JJJ, van der Veken BJ, Purohita SS, Guirgis GA (2013) Conformational and structural studies of ethynylcyclopentane from temperature dependent Raman spectra of xenon solutions, infrared spectra, and ab initio calculations. J Mol Struct 1044:10-20

805 CAS RN: 340-07-8 MGD RN: 540390 GED combined with MS and augmented by QC computations

2,2,2-Trifluoro-1-(1-piperidinyl)ethanone 1-(Trifluoroacetyl)piperidine C7H10F3NO C1 O

F

Bonds N(1)–C(1) N(1)–C(5) N(1)–C(6) C(1)–C(2) C(2)–C(3) C(6)–C(7) C(6)=O C(7)–F(1) C(7)–F(2)

rh1 [Å] a 1.474(4) 1.474(4) 1.366(3) 1.527(3) 1.529(3) 1.550(3) 1.217(3) 1.350(3) 1.321(3)

Bond angles C(1)–N(1)–C(5) C(1)–N(1)–C(6) C(5)–N(1)–C(6) N(1)–C(6)–C(7) N(1)–C(6)=O Ʃ(C–N–C) c

θh1 [deg] b

Dihedral angles N(1)–C(1)–C(2)–C(3) C(1)–C(2)–C(3)–C(4) C(1)–N(1)–C(6)–C(7) C(1)–N(1)–C(6)=O O=C(6)–C(7)–F(2) Flap(N) d Flap(Cγ) f

τh1 [deg] b

ϕg

N F

F

114.3(4) 117.8(4) 127.9(4) 117.1(4) 125.3(5) 360(1)

52.8(20) -51.6(20) 179(5) -1(5) 1.4(9) 51(2) e 47(2) e 53(2)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parenthesized uncertainties in units of the last significant digit are 3σ values. c Sum of the C–N–C angles. d Angle between the C(1)–N(1)–C(5) and C(1)–C(2)...C(4)–C(5) planes. e Dependent parameter. f Angle between the C(2)–C(3)–C(4) and C(1)–C(2)...C(4)–C(5) planes. g Angle between the N–C exocyclic bond and the C(1)–C(2)...C(4)–C(5) plane. According to results of the GED analysis (Teffusion cell = 286(3) K) and B3LYP/6-311G** computations, the title molecule exists as a single conformer possessing a chair conformation of the ring with the substituent group located between the axial and equatorial positions. Nine atoms of this conformer (two Cα atoms with their equatorial H atoms and the N, C(6), C(7) and F(2) atoms) were found to be in one plane. According to NBO

9 Molecules with Seven to Nine Carbon Atoms

705

analysis, stabilization of the conformer occurs due to influence of the strong conjugation between the electron lone pair on the nitrogen atom and the C=O bond. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from computations at the level of theory as indicated above. Small differences between analogues parameters were fixed at the values from computation at the level of theory as indicated above. Shlykov SA, Phien TD, Trang NH (2017) Orbital interaction between electron lone pair and carbonyl group in N-trifluoroacetylpiperidine and N-piperidine amides: Planar and non-planar nitrogen bond configurations. Tetrahedron 73 (35):5311-5320

3-Oxatricyclo[3.2.1.02,4]octane exo-2,3-Epoxynorborane C7H10O Cs

806 CAS RN: 278-74-0 MGD RN: 890586 MW supported by QC calculations

O

Bonds C(1)–C(6) C(5)–C(6) C(1)–C(2) C(1)–C(7) C(2)–O C(2)–C(3)

r0 [Å] a 1.556(5) 1.568(4) 1.523(6) 1.541(3) 1.445(5) 1.470(4)

rs [Å] a 1.558(11) 1.562(3) 1.509(11) 1.543(5) 1.438(20) 1.465(4)

Bond angles C(6)–C(1)–C(7) C(1)–C(6)–C(5) C(1)–C(7)–C(4) C(2)–C(1)–C(7) C(1)–C(2)–C(3) C(2)–O–C(3) O–C(2)–C(1)

θ0 [deg] a

θs [deg] a

Dihedral angles C(1)–C(7)–C(4)–C(5) C(5)–C(4)–C(3)–O C(2)–C(3)–C(4)–C(5) C(5)–C(6)–C(1)–C(7) C(2)–C(1)–C(6)–C(5) C(7)–C(4)–C(3)–O O–C(2)–C(3)–C(4) C(1)–C(2)–C(3)–C(4) C(1)–C(6)–C(5)–C(4)

τ0 [deg] a 123.4(5) -45.0(4) -108.0(4) 144.6(4) -109.6(4) -149.6(5) -69.2(5) 0b 0b 103.8

τs [deg] a 123.0(10) -45.2(14) -108.2(7) 144.3(8) -109.9(7) -149.6(18) -68.6(5) 0b 0b 104.1

ϕc

100.8(3) 103.1(3) 95.1(2) 102.3(4) 105.3(4) 61.2(3) 115.4(4)

100.6(7) 103.1(5) 94.8(4) 102.3(6) 105.5(5) 61.3(11) 116.0(18)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Assumed according to symmetry. c Angle between the C(1)–C(2)–C(3)–C(4) and C(1)–C(6)–C(5)–C(4) planes. b

706

9 Molecules with Seven to Nine Carbon Atoms

The rotational spectrum of the title compound was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency range between 4 and 18 GHz. The r0 and rs structures of the heavy-atom skeleton were determined from the ground-state rotational constants of six isotopic species (main, four 13C and 18O) assuming Cs symmetry. Écija P, Uriarte I, Basterretxea FJ, Millán J, Lesarri A, Fernández JA, Cocinero EJ (2015) Structural distortion of the epoxy groups in norbornanes: a rotational study of exo-2,3-epoxynorbornane. ChemPhysChem 16(12):26092614

807 CAS RN: 187404-56-4 MGD RN: 152006 MW

Methoxybenzene – water (1/1) Anisole – water (1/1) C7H10O2 Cs O

CH3

Distances O…O O(2)…H(1) O(2)…H(2) Angle O(2)…O(1)–C(1)

a

r0 [Å] C6H5OCD3 ‧ H2O 2.923(2) 3.06 3.54

r0 [Å] C6D5OCH3 ‧ D2O 2.950(1) 3.48 3.10

θ0 [deg] a

θ0 [deg] a

138.98(3)

O H

a

H

126.74(2)

Copyright 2017 with permission from Elsevier [a].

a

Parenthesized uncertainty in units of the last significant digit.

Complementary to the study of the binary complex of anisole with water [b], the rotational spectra of different isotopic species were recorded by a pulsed-jet FTMW spectrometer in the frequency region between 6 and 18 GHz. Various multiply deuterated isotopic species were studied in order to observe the structural effects upon deuteration. It was revealed that the deuteration of the methyl and phenyl hydrogens does not affect the structure of the complex, whereas the deuteration of the water moiety leads to large structural changes. The partial r0 structure was determined for seven isotopic species (D3, D4, two D5, D6, D7 and D3/18O). The structures are given here for the least- and most-deuterated species, C6H5OCD3‧H2O and C6D5OCH3‧D2O, respectively. a. Giuliano BM, Melandri S, Caminati W (2017) Effects of deuteration of the methyl and phenyl hydrogens on the rotational spectrum of anisole-water. J Mol Spectrosc 337(1):86-89 b. Giuliano BM, Caminati W (2005) Isotopomeric conformational change in anisole-water. Angew Chem 117(4):609-612; Angew Chem Int Ed 44(4):603-606

808 CAS RN: MGD RN: 429430 MW supported by ab initio calculations

2-Hydroxy-2-cyclohexen-1-one – formic acid (1/1) C7H10O4 C1 OH

Distances Rcm b

r0 [Å] a 4.591(2)

O

O

H

OH

9 Molecules with Seven to Nine Carbon Atoms

H(2)…O(2) H(1)…O(1)

707

1.973(30) 1.975(30)

Copyright 2014 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Center-of-mass separation of two subunits.

The rotational spectrum of the binary complex of formic acid and the enol form of 1,2-cyclohexanedione was recorded by a pulsed-jet FTMW spectrometer in the spectral range between 4.5 and 9 GHz. The partial r0 structure was determined from the ground state rotational constants of four isotopic species (main, two D and D2) assuming that the structural parameters of the monomer subunits were not changed upon complexation. Pejlovas AM, Barfield M, Kukolich SG (2014) Microwave spectrum and molecular structure parameters for the 1,2-cyclohexanedione (monoenolic)-formic acid dimer. Chem Phys Lett 613:86-89

809 CAS RN: 766-05-2 MGD RN: 856716 MW augmented by QC calculations

Bonds C(1)–C(2) C(2)–C(4) C(6)–C(4) C(6)–C(7) C(1)–H(2) C(1)–H(3) C(2)–H(4) C(2)–H(5) C(4)–H(6) C(4)–H(7) C(6)–H(1) C(7)≡N(7) Bond angles C(3)–C(1)–C(2) C(1)–C(2)–C(4) C(6)–C(4)–C(2) C(4)–C(6)–C(5) C(7)–C(6)–C(4) C(2)–C(1)–H(2) C(2)–C(1)–H(3) H(2)–C(1)–H(3) C(1)–C(2)–H(4) C(1)–C(2)–H(5) C(4)–C(2)–H(4)

Cyclohexanecarbonitrile Cyanocyclohexane C7H11N Cs (axial) Cs (equatorial)

axial r0 [Å] a 1.536(3) 1.532(3) 1.544(3) 1.470(3) 1.092(3) 1.088(3) 1.090(3) 1.088(3) 1.090(3) 1.087(3) 1.089(3) 1.162(3)

equatorial r0 [Å] a 1.536(3) 1.532(3) 1.544(3) 1.464(3) 1.091(3) 1.088(3) 1.091(3) 1.088(3) 1.090(3) 1.087(3) 1.092(3) 1.161(3)

θ0 [deg] a

θ0 [deg] a

111.1(5) 111.6(5) 111.4(5) 110.5(5) 110.0(5) 109.2(5) 110.2(5) 106.8(5) 109.4(5) 110.5(5) 108.0(5)

110.9(5) 110.8(5) 110.2(5) 110.9(5) 110.8(5) 109.2(5) 110.3(5) 106.8(5) 109.2(5) 110.6(5) 110.0(5)

C

N

708

9 Molecules with Seven to Nine Carbon Atoms

C(4)–C(2)–H(5) H(4)–C(2)–H(5) C(6)–C(4)–H(6) C(6)–C(4)–H(7) C(2)–C(4)–H(6) C(2)–C(4)–H(7) H(6)–C(4)–H(7) C(4)–C(6)–H(1) C(7)–C(6)–H(1) C(6)–C(7)≡N(7)

110.3(5) 106.8(5) 107.5(5) 110.0(5) 109.2(5) 111.2(5) 107.4(5) 109.6(5) 107.0(5) 178.8(5)

109.4(5) 106.8(5) 108.4(5) 109.9(5) 110.2(5) 110.9(5) 107.1(5) 108.5(5) 107.3(5) 179.0(5)

Dihedral angle C(1)–C(2)–C(4)–C(6)

τ0 [deg] a

τ0 [deg] a

55.6(10)

56.9(10)

Copyright 2010 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

equatorial

axial

The rotational spectrum of the title compound was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 11 and 21 GHz. The spectrum was assigned to the chair-axial and chair-equatorial conformers. The enthalpy difference between these conformers was determined to be 0.75(11) kJ mol-1 by temperaturedependent IR vibrational spectroscopy. The percentage of the most stable chair-axial conformer was estimated to be 58(3) % (at ambient temperature). The r0 structural parameters of each conformer were obtained by adjusting the MP2_full/6-311+G(d,p) structure to the experimental ground-state rotational constants of one isotopic species. Durig JR, Ward RM, Conrad AR, Tubergen MJ, Nelson KG, Groner P, Gounev TK (2010) Microwave, Raman, and infrared spectra, r0 structural parameters, conformational stability, and vibrational assignment of cyanocyclohexane. J Mol Struct 967(1-3):99-111

810 CAS RN: 3173-53-3 MGD RN: 585703 MW augmented by QC calculations

Isocyanatocyclohexane Cyclohexyl isocyanate C7H11NO Cs (equatorial) N

C O

Distances C(5)=N C(5)=O C(1)–N C(1)–C(2)

r0 [Å] 1.208 1.167 1.455 1.534

a

9 Molecules with Seven to Nine Carbon Atoms

C(2)–C(3) C(3)–C(4) C(1)–H(1) C(2)–H(3) C(2)–H(2) C(3)–H(5) C(3)–H(4) C(4)–H(7) C(4)–H(6)

1.529 1.534 1.096 1.095 1.099 1.098 1.095 1.095 1.098

Bond angles N=C(5)=O C(1)–N=C(5) C(2)–C(1)–N C(2)–C(1)–C(2') C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(3') N–C(1)–H(1) C(2)–C(1)–H(1) C(1)–C(2)–H(3) C(1)–C(2)–H(2) C(3)–C(2)–H(3) C(3)–C(2)–H(2) C(2)–C(3)–H(5) C(2)–C(3)–H(4) C(4)–C(3)–H(5) C(4)–C(3)–H(4) C(3)–C(4)–H(7) C(3)–C(4)–H(6)

θ0 [deg] a

Dihedral angles C(1)–C(2)…C(2')–C(3') C(2')–C(3')…C(3)–C(4)

τ0 [deg] a

709

172.5 135.3 110.9 111.1 110.3 111.1 110.8 106.1 108.8 109.4 108.3 111.2 110.1 109.4 109.6 109.3 110.6 110.3 109.2

128.0 129.1

Copyright 2013 with permission from Elsevier.

a

Uncertainties were not given in the original paper.

The rotational spectrum of the title compound was recorded by a supersonic-jet FTMW spectrometer in the spectral range between 10 and 21 GHz. The rotational lines were assigned to the more stable conformer, equatorial-trans, with the equatorial isocyanato group and the trans C-N=C=O chain. The r0 structure was determined by fitting the MP2_full/6-311+G(d,p) structure to the ground-state rotational constants of one isotopic species. Two conformers, equatorial-trans and axial-trans, were identified in the temperature-dependent IR vibrational spectra. The enthalpy difference was obtained to be 4.75(47) kJ mol-1. Zhou SX, Ward RM, Tubergen MJ, Gurusinghe RM, Durig JR (2013) Microwave, infrared, and Raman spectra, r0 structural parameters, conformational stability and ab initio calculations of cyclohexyl isocyanate. Chem Phys 415:44-55

811 CAS RN: 925212-13-1 MGD RN: 209341

Methoxybenzene – ammonia (1/1) Anisole – ammonia (1/1) C7H11NO

710

9 Molecules with Seven to Nine Carbon Atoms

MW augmented by ab initio calculations

C1

O

CH3

N

H

H

H

Dihedral angle N…O(2)–C(1)–C(2)

τ0 [deg] a 76.8

Reprinted with permission. Copyright 2009 American Chemical Society.

a

Uncertainty was not given in the original paper.

The rotational spectrum of the title complex was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 6 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and 15N); the remaining structural parameters were fixed to the values from MP2_full/6-311++G** calculation. The complex is stabilized via three weak contacts, N–H…O, C(methyl)–H…N and N–H…π. Giuliano BM, Maris A, Melandri S, Caminati W (2009) Pure rotational spectrum and model calculations of anisole-ammonia. J Phys Chem A 113(52):14277-14280

812 CAS RN: 1245598-97-3 MGD RN: 372421 GED combined with MS and augmented by QC computations

Bonds Si–C(1) Si–C(7) Si–C(6) C(1)–C(2) C(2)–C(3) C(7)–F(1) C(7)–F(2) C(6)–H(1) C(1)–H(4) C–H

rh1 [Å] a,b 1.871(4) 1 1.929(20) c 1.869(4) 1 1.536(3) 2 1.528(3) 2 1.362(3) 3 1.362(3) 3 1.088(3) 4 1.091(3) 4 1.092(3) d

Bond angles C(1)–Si–C(7) C(1)–Si–C(6) C(1)–Si–C(5) Si–C(1)–C(2) Si–C(7)–F(1) F(1)–C(7)–F(2) Si–C(6)–H(1) H(1)–C(6)–H(2) H–C–H g

θh1 [deg] a

Dihedral and other angles

1-Methyl-1-(trifluoromethyl)silacyclohexane C7H13F3Si Cs (axial) Cs (equatorial) Si

CF3

108.6(7) 114.3(4) 108.1(7) 111.1(5) 112.9(5) 105.6(11) 110.9 e 108.1 f 102.6 d

axial

CH3

τh1 [deg] a

equatorial

9 Molecules with Seven to Nine Carbon Atoms

tilt(CF3) h tilt(CH3) i rock(C(1)) j rock(C(2)) k rock(C(3)) l flap(C(3)) m flap(Si) n C(5)–Si–C(1)–C(2) C(1)–C(2)–C(3)–C(4) Si–C(1)–C(2)–C(3)

0.0 f 0.0 e 2.8 e -0.3 e -0.4 e 50.9(44) 33.7(23) -35.9(25) -60.2(49) 49.1(15)

711

56.2(40) 28.9(22) -31.1(30)

Copyright 2010 with permission from Elsevier.

axial

equatorial

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; difference between parameters in each group was assumed at the value from MP2/6-31G** computation. c Derived from refined r(Si−C(1)) and difference to it. d Average value. e Adopted from computation at the level of theory as indicated above. f Fixed. g In the CH2 groups. h Tilt angle of the CF3 group defined as 2/3[∠(Si–C(7)–F(1)) − ∠(Si–C(7)–F(2))]. i Tilt angle of the CH3 group defined as 2/3[∠(Si–C(6)–H(1)) − ∠(Si–C(6)–H(2))]. j Rock angle of the CH2 group at the C(1) atom defined as 1/2[∠(Si–C(1)–H(4)) − ∠(Si–C(1)–H(5)) + ∠(C(2)– C(1)–H(4)) − ∠(C(2)–C(1)–H(5))]. k Rock angle of the CH2 group at the C(2) atom defined as 1/2[∠(C(1)–C(2)–H(8)) − ∠(C(1)–C(2)–H(9)) + ∠(C(3)–C(2)–H(8)) − ∠(C(3)–C(2)–H(9))]. l Rock angle of the CH2 group at the C(3) atom defined as 1/2[∠(C(2)–C(3)–H(6)) − ∠(C(2)–C(3)–H(7)) + ∠(C(4)–C(3)–H(6)) − ∠(C(4)–C(3)–H(7))]. m Acute angle between the C(1)C(2)C(4)C(5) and C(2)C(3)C(4) planes. n Acute angle between the C(1)C(2)C(4)C(5) and C(1)SiC(5) planes. The GED experiment was carried out at Tnozzle = 262 K. The title compound was found to exist as a mixture of two conformers, characterized by the axial and equatorial positions of the methyl groups with respect to the ring. Overall Cs symmetry, chair conformation of the ring, local C3v symmetry for the methyl group and local Cs symmetry for the CF3 group were assumed. The ratio of conformers was determined to be axial : equatorial = 51(5) : 49(5) (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from MP2/6-31G** computation. Structural differences between conformers were assumed at the computed values except for dihedral angles refined independently (see table). Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Girichev GV, Giricheva NI, Hassler K, Arnason I (2010) Conformational properties of 1-fluoro-1-methyl-silacyclohexane and 1-methyl-1-trifluoromethyl-1-

712

9 Molecules with Seven to Nine Carbon Atoms

silacyclohexane: Gas electron diffraction, low-temperature NMR, temerature-dependent Raman spectroscopy, and quantum chemical calculations. J Mol Struct 978 (1-3):209-219

813 CAS RN: 61676-28-6 MGD RN: 382881 GED combined with MS and augmented by QC computations

1,3,3-Trimethyl-1-aza-3-silacyclohexane C7H17NSi C1 CH3

Si

Bonds C(2)–Si(3) Si(3)–C(4) Si(3)–C(7) Si(3)–C(8) C(4)–C(5) C(5)–C(6) N(1)–C(2) N(1)–C(6) N(1)–C(9) C(2)–H(1)

rh1 [Å] a,b 1.896(4) 1 1.885(4) 1 1.881(4) 1 1.881(4) 1 1.538(3) 2 1.529(3) 2 1.470(3) 3 1.465(3) 3 1.457(3) 3 1.115(2)

Bond angles C(2)–Si(3)–C(4) C(2)–Si(3)–C(7) Si(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(4)–H(3) Si(3)–C(2)–H(1) N(1)–C(2)–H(1) H(1)–C(2)–H(2) C(2)–N(1)–C(9) C(2)–N(1)–C(6) C(6)–N(1)–C(9) Σ(C–N–C) c

θh1 [deg] a,b

Dihedral angles C(2)–Si(3)–C(4)–C(5) C(2)–Si(3)–C(7)–H(4) C(2)–Si(3)–C(8)–H(5) Si(3)–C(4)–C(5)–C(6) C(2)–N(1)–C(9)–H(6)

τh1 [deg] a,b

CH3

N CH3

102.9(3) 110.2(4) 111.4(4) 112.5(6) 110.5(10) 112.6(9) 115.4(10) 105.0(7) 110.8(5) 4 113.3(5) 4 110.8(5) 4 334.9(9)

41.0(8) 177.9(4) 175.4(4) -52.2(1) -63.4(2)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit were not specified, probably estimated total errors. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from calculation at the level of theory as indicated below. c Sum of the valence angles at the nitrogen atom. The GED experiment was carried out at Teffusion cell = 271(3) K. The title molecule was found to exist as a single conformer with a slightly distorted chair conformation of the ring and the N−C(methyl) bond in the equatorial position.

9 Molecules with Seven to Nine Carbon Atoms

713

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/aug-cc-pVTZ calculation. The barrier to the ring inversion was determined to be very high (38.1 kJ mol−1) by low temperature NMR spectroscopy. Shainyan BA, Kirpichenko SV, Shlykov SA, Kleinpeter E (2012) Structure and conformational properties of 1,3,3-trimethyl-1,3-azasilinane: Gas electron diffraction, dynamic NMR, and theoretical study. J Phys Chem A 116 (1):784-789

814 CAS RN: 647-12-1 MGD RN: 216971 MW augmented by DFT calculations

2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Pentadecafluorooctanenitrile Perfluorooctanonitrile C8F15N C1 F

F

F

F

F

F

N

F

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(7) C(7)–C(8)

r0 [Å] a 1.477 1.561 1.562 1.564 1.564 1.560 1.558

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(7) C(6)–C(7)–C(8)

θ0 [deg] a

Dihedral angles C(1)–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–C(7) C(5)–C(6)–C(7)–C(8)

τ0 [deg] a

C

F

F

F

F

F

F

F

F

109.79 113.59 112.55 112.67 112.77 113.77

168.98 161.99 161.94 161.75 162.74

Copyright 2011 with permission from Elsevier.

a

Uncertainties were not given in the original paper.

The rotational spectrum of the title compound was recorded in a pulsed supersonic jet by an FTMW spectrometer in the spectral region between 6 and 10 GHz. The r0 structure of the carbon backbone was obtained by fitting the scaled PBE0/aug-cc-pVTZ structure to the ground-state rotational constants determined for main isotopic species. The chain of seven perfluorinated C atoms twists about 104°. Bailey WC, Bohn RK, Dewberry CT, Grubbs GS, Cooke SA (2011) The structure and helicity of perfluorooctanonitrile, CF3-(CF2)6-CN. J Mol Spectrosc 270(1):61-65

714

9 Molecules with Seven to Nine Carbon Atoms

815 CAS RN: 935-16-0 MGD RN: 478528 GED augmented by DFT computations

1,4-Diisocyanobenzene p-Diisocyanobenzene C8H4N2 D2h (see comment) C

Bonds C(1)–C(2) C(2)–C(3) C(1)–N(7) N(7)≡C(9) C(2)–H

rg [Å] a 1.400(3) b 1.390(5) b 1.386(3) 1.177(2) 1.099 c

Angles C(2)–C(1)–C(6) C(1)–C(2)–C(3) C(3)–C(2)–H

θa [deg] a

ϕf

N

N

C

120.6(2) 119.7(1) d 120.7(2) e 7.3(9)

Reproduced with permission of SNCSC [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors. Difference between the C–C bond lengths was assumed at the value from B3LYP/6-311++G* calculation. c Assumed. d Dependent parameter. e Difference between the C(1)–C(2)–H and C(3)–C(2)–H bond angles was assumed at the value from calculation as indicated above. f Angle between the C(1)…C(9) and the C(1)…C(4) lines. b

The GED data from Ref. [b] (Tnozzle =384 K) were reinvestigated. Local D2h symmetry for the benzene ring and local C∞v symmetry for each of the isocyano groups were assumed. The averaged geometry was assumed to have overall C2v symmetry, whereas the equilibrium structure possesses the D2h point-group symmetry. a. Campanelli AR, Domenicano A, Ramondo F, Hargittai I (2012) Molecular structure of p-diisocyanobenzene from gas-phase electron diffraction and theoretical calculations and effects of intermolecular interactions in the crystal on the benzene ring geometry. Struct Chem 23 (1):287-295 b. Colapietro M, Domenicano A, Portalone G, Torrini I, Hargittai I, Schultz G (1984) Molecular structure and ring distotions of p-diisocyanobenzene in the gaseous phase and in the crystal. J Mol Struct 125:19-32

816 CAS RN: 85-44-9 MGD RN: 413665 MW augmented by ab initio calculations

Bonds C(1)–O(9) C(1)=O(10) C(1)–C(2) C(2)–C(3)

1,3-Isobenzofurandione Phthalic anhydride C 8H 4O 3 C2v O

r0 [Å] a 1.397 1.195 1.479 1.390

O

O

9 Molecules with Seven to Nine Carbon Atoms

C(2)–C(7) C(3)–C(4) C(4)–C(5) C(3)–H C(4)–H

1.389 1.397 1.408 1.086 b 1.086 b

Bond angles C(1)–O(9)–C(8) O(9)–C(8)=O(11) O(9)–C(8)–C(7) O(11)=C(8)–C(7) C(8)–C(7)–C(2) C(8)–C(7)–C(6) C(6)–C(7)–C(2) C(7)–C(6)–C(5) C(7)–C(6)–H C(5)–C(6)–H C(6)–C(5)–C(4) C(6)–C(5)–H C(4)–C(5)–H

θ0 [deg] a

715

110 122 108 131 108 130 122 117 121 122 121 120 119

Copyright 2014 with permission from Elsevier.

a b

Uncertainties were not given in the original paper. Fixed at the value from MP2/6-311++G** calculation.

The rotational spectrum of the title compound was recorded by pulsed-beam Balle-Flygare type FTMW spectrometers in the frequency region between 4 and 14 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, four 13C and two 18O). Pejlovas AM, Sun M, Kukolich SG (2014) Microwave measurements of the spectra and molecular structure for phthalic anhydride. J Mol Spectrosc 299:43-47

817 CAS RN: MGD RN: 503580 IR

Ethyne – carbon dioxide (2/4) Acetylene – carbon dioxide (2/4) C 8H 4O 8 D2d H

Distances Rcm,1 b Rcm,2 c Rcm,3 d

r0 [Å] a 7.25 3.65 5.41

Reproduced with permission from the PCCP Owner Societies.

a

Uncertainties were not given in the original paper. Distances between the centers of mass of the farthest CO2 subunits. c Distances between the centers of mass of the nearest CO2 subunits. d Distances between the centers of mass of the HCCH subunits. b

C

C

H

2

O

C

O

4

716

9 Molecules with Seven to Nine Carbon Atoms

The rotationally resolved IR spectrum of the hexamer of acetylene with carbon dioxide was recorded in a supersonic jet by a tunable diode laser spectrometer in the region of the ν3 fundamental band of CO2 at about 2350 cm-1. The partial r0 structure was determined from the ground-state rotational constants under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The hexamer forms a box-shaped complex with D2d symmetry, which is supported by the observed intensity alternation of the rovibrational spectrum. Rezaei M, Norooz Oliaee J, Moazzen-Ahmadi N, McKellar ARW (2016) Infrared spectra reveal box-like structures for a pentamer and hexamer of mixed carbon dioxide-acetylene clusters. Phys Chem Chem Phys 18(3):1381-1385

818 CAS RN: 2561-17-3 MGD RN: 498447 MW augmented by ab initio calculations

1-Ethynyl-3-fluorobenzene 3-Fluorophenylacetylene C8H5F Cs F

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–C(7) C(7)≡C(8)

r0 [Å] a 1.412(20) 1.377(19) 1.380(4) 1.396(2) 1.402(3) 1.400(19) 1.426(6) 1.218 b

rs [Å] a 1.375(27) 1.381(13) 1.379(4) 1.400(2) 1.388(3) 1.432(37) 1.432(11) 1.207(2)

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(5)–C(6)–C(1) C(2)–C(1)–C(7) C(6)–C(1)–C(7) C(1)–C(7)≡C(8)

θ0 [deg] a

θs [deg] a

119.78(69) 118.29(68) 123.51(34) 117.95(11) 120.77(10) 119.70(23) 119.92(146) 120.29(96) 179.95 b

C

C

H

119.70(93) 118.76(120) 123.58(27) 117.82(11) 120.57(10) 119.57(36) 121.87(265) 118.43(179) 178.85(150)

Copyright 2016 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Assumed at the value from MP2/6-311++G(2d,2p) calculations.

The rotational spectrum of the title compound was recorded in a supersonic jet by chirped-pulse and BalleFlygare type FTMW spectrometers in the frequency region between 6 and 18 GHz. The r0 structure of the heavy-atom skeleton was determined from the ground-state rotational constants of nine isotopic species (main and eight 13C); the structural parameters related to H and F atoms were fixed to the MP2 values (as above). Jang H, Ka S, Peebles SA, Peebles RA, Oh JJ (2016) Microwave spectrum, structure and dipole moment of 3fluorophenylacetylene (3FPA). J Mol Struct 1125:405-412

9 Molecules with Seven to Nine Carbon Atoms

717

819

1-Ethynyl-4-fluorobenzene 4-Fluorophenylacetylene C8H5F

CAS RN: 766-98-3

MGD RN: 508840 MW supported by ab initio calculations

C2v

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–C(7) C(7)≡C(8) C(4)–F

r0 [Å] a 1.402(2) 1.393(4) 1.388(1) 1.436(2) 1.209(1) 1.348(1)

rs [Å] a 1.405(35) 1.375(4) 1.386(28) 1.439(2) 1.208(1)

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–C(7)

θ0 [deg] a

θs [deg] a

119.8(2) 120.3(2) 118.5(1) 122.7(1) 120.1(1)

F

H

C

C

119.0(2) 120.7(9) 118.7(7) 122.4(1) 120.5(26)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by broadband chirped-pulse and Balle-Flygare type FTMW spectrometers in the frequency region between 6 and 18 GHz. The r0 and rs structures of the heavy-atom skeleton were determined from the ground-state rotational constants of seven isotopic species (main and six 13C). Jang H, Ka S, Dikkumbura AS, Peebles RA, Peebles SA, Oh JJ (2017) Microwave spectrum, structure and dipole moment of 4-fluorophenylacetylene (4FPA). J Mol Struct 1133:320-328

820 CAS RN: 91-56-5 MGD RN: 505455 GED augmented by QC computations

Bonds C(3a)–C(7a) C(7a)–N C(2)–N C(2)–C(3) C(3)–C(3a) C(7)–C(7a) C(6)–C(7) C(5)–C(6) C(4)–C(5) C(4)–C(3a) C(2)=O C(3)=O

1H-Indole-2,3-dione Isatin C8H5NO2 Cs O

ra [Å] a,b 1.404(7) 1 1.405(7) 1 1.384(7) 1 1.573(7) 1 1.478(7) 1 1.387(7) 1 1.399(7) 1 1.398(7) 1 1.395(7) 1 1.388(7) 1 1.203(4) 2 1.203(4) 2

O

N H

718

9 Molecules with Seven to Nine Carbon Atoms

N–H C–H

1.006 c 1.086(13) d

Bond angles C(3a)–C(7a)–N C(7a)–N–C(2) C(3)–C(2)–N C(2)–C(3)–C(3a) C(3)–C(3a)–C(7a) C(7)–C(7a)–C(3a) C(6)–C(7)–C(7a) C(5)–C(6)–C(7) C(4)–C(5)–C(6) C(3a)–C(4)–C(5) C(7a)–C(3a)–C(4) O=C(2)–N O=C(3)–C(2)

θh1 [deg] a,b 110.9(8) 3 112.4(8) 3 105.2(8) e 105.2(8) e 107.9(8) e 120.8(5) 4 117.2(5) 4 121.9(5) 4 119.7(5) e 118.3(5) e 120.9(5) e 128.4(20) 124.3(12)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from M06-2X/aug-cc-pVTZ computation. c Assumed at the value from computation as indicated above. d Average value. e Derived according to the ring closure conditions. b

The GED experiment was carried out at Tnozzle = 461 K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X/aug-cc-pVTZ computation. The (O=)C–C(=O) bond was found to be remarkably lengthened in comparison to the typical C(sp2)–C(sp2) bond length value. Belyakov AV, Nikolaenko KO, Davidovich PB, Ivanov AD, Garabadzhiu AV, Rykov AN, Shishkov IF (2017) Molecular structure of gaseous isatin as studied by electron diffraction and quantum chemical calculations. J Mol Struct 1132:44-49

821 CAS RN: 85-41-6 MGD RN: 460107 MW supported by QC calculations

1H-Isoindole-1,3(2H)-dione Phthalimide C8H5NO2 C2v O

Bonds C(1)–C(2) C(1)–C(6) C(1)–C(7) C(7)–N C(5)–C(6) C(4)–C(5)

r0 [Å] a 1.388 1.389 1.491 1.396 1.400 1.399

Bond angles C(1)–C(2)–C(3)

θ0 [deg] a 122

NH

O

9 Molecules with Seven to Nine Carbon Atoms

C(1)–C(2)–C(8) C(3)–C(2)–C(8) N–C(8)–C(2) N–C(8)=O C(2)–C(8)=O C(7)–N–C(8) H–N–C(8) C(2)–C(3)–C(4) C(2)–C(3)–H H–C(3)–C(4) C(3)–C(4)–C(5) C(5)–C(4)–H H–C(4)–C(3)

719

108 130 105 126 129 113 123 117 121 122 121 119 120

Copyright 2015 with permission from Elsevier.

a

Uncertainties were not given in the original paper.

The rotational spectrum of the title compound was recorded by a pulsed-jet Balle-Flygare type FTMW spectrometer in the frequency region between 4.8 and 9.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main and four 13C). A small inertial defect indicated a planar structure. Pejlovas AM, Lin W, Oncer O, Kukolich SG (2015) Microwave spectrum and the gas phase structure of phthalimide. J Mol Spectrosc 317(5):59-62

822 CAS RN: 58632-96-5 MGD RN: 536536 GED combined with MS and augmented by QC computations

3-Amino-1,2-benzenedicarbonitrile 3-Aminophthalonitrile C8H5N3 C1 NH2

a,b

Bonds C–C(ring) C(4)–C(5) C(5)–C(6) C(3)–C(4) C(2)–C(3) C(1)–C(2) C(1)–C(6) C(2)–C(8) C(1)–C(7) C(8)≡N(2) C(7)≡N(1) C(3)–N(3) C(6)–H C(5)–H C(4)–H N(3)–H(2) N(3)–H(1)

re [Å] 1.397(3) c 1.382(3) 1 1.394(3) 1 1.403(3) 1 1.406(3) 1 1.407(3) 1 1.389(3) 1 1.431(3) 2 1.437(3) 2 1.155(2) 3 1.154(2) 3 1.370(3) 1.085(18) 4 1.087(18) 4 1.088(18) 4 0.964(36) 5 0.967(36) 5

Bond angles C(3)–C(4)–C(5)

θe [deg] b,d 121.0(2) 6

rg [Å]

a

1.389(3) 1.403(3) 1.414(3) 1.418(3) 1.416(3) 1.398(3) 1.439(3) 1.446(3) 1.160(2) 1.158(2) 1.365(3) 1.104(18) 1.106(18) 1.107(18) 0.978(36) 0.981(36)

N

C

C N

720

9 Molecules with Seven to Nine Carbon Atoms

C(4)–C(5)–C(6) C(2)–C(3)–C(4) C(1)–C(6)–C(5) C(1)–C(2)–C(3) C(6)–C(1)–C(2) C(3)–C(2)–C(8) C(6)–C(1)–C(7) C(2)–C(8)≡N(2) C(1)–C(7)≡N(1) C(2)–C(3)–N(3) C(5)–C(6)–H C(4)–C(5)–H C(3)–C(4)–H C(3)–N(3)–H(2) C(3)–N(3)–H(1) Ʃ[N(3)] f

121.2(2) 6 117.9(2) e 118.4(2) 6 120.4(2) e 120.8(2) e 117.4(11) 119.0(10) 170.0(35) 176.0(33) 120.0(7) 116.8(27) 7 114.5(27) 7 114.2(27) 7 114.7(26) 8 115.2(26) 8 341.2(73)

Dihedral angles C(5)–C(4)–C(3)–N(3) C(4)–C(3)–C(8)≡N(2) C(5)–C(6)–C(7)≡N(1)

τe [deg] d

170.8(77) 160.5(123) 172.1(104)

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the computed values of CCSD(T)_ae/cc-pwCVQ quality. c Average value. d Parenthesized uncertainties in units of the last significant digit are 2.5σ values. e Dependent parameter. f Sum of the bond angles around the nitrogen atom. The combined GED/MS experiment was carried out at Teffusion cell = 394(5) K. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B3LYP/cc-pVTZ quadratic and cubic force fields taking into account non-linear kinematic effects. It was shown that the anharmonic vibrational effects, ∆re = rh1 − re, are several times larger than the experimental uncertainties; for example, for the C–C and C–N bond lengths they are up to 0.014 Å. Fine structural effects due to intramolecular charge transfer, caused by interaction of two different types of substituents, namely the electron-donating amino group and the electron-withdrawing nitrile groups, became evident due to high accuracy of the computed structure of CCSD(T)_ae/cc-pwCVQ quality. Vogt N, Savelyev DS, Giricheva NI, Islyaikin MK, Girichev GV (2016) Accurate determination of equilibrium structure of 3-aminophthalonitrile by gas electron diffraction and coupled-cluster computations: Structural effects due to intramolecular charge transfer. J Phys Chem A 120 (44):8853-8861

823 CAS RN: 536-74-3 MGD RN: 182188 MW augmented by DFT calculations

Bonds C(1)–C(2)

Ethynylbenzene Phenylacetylene C 8H 6 C2v

r (m2) [Å] a 1.3945(7)

r see [Å] a 1.3990(2)

9 Molecules with Seven to Nine Carbon Atoms

721

C(2)–C(3) C(3)–C(4 ) C(1)–C(7) C(7)≡C(8) C(2)–H C(3)–H C(4)–H C(8)–H

1.3914(7) 1.3932(4) 1.4407(7) 1.2057(3) 1.0991(26) 1.0850(5) 1.0832(5) 1.0570(3)

1.3886(2) 1.3912(1) 1.4304(2) 1.2071(1) 1.0776(2) 1.0802(1) 1.0802(1) 1.0607(1)

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(1)–C(2)–H C(4)–C(3)–H

θ (m2) [deg] a

θ see [deg] a

120.24(9) 119.73(1) 120.23(2) 119.83(2) 118.03(25) 119.70(4)

C

C

H

119.42(2) 120.12(1) 120.26(1) 119.82(1) 119.49(3) 120.14(1)

Reprinted with permission. Copyright 2013 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The mass-dependent structure r (m2) was determined from the previously published experimental ground-state rotational constants. The semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated from the B3LYP/6-311+G(3df,2pd) harmonic and anharmonic (cubic) force fields. Rudolph HD, Demaison J, Császár AG (2013) Accurate determination of the deformation of the benzene ring upon substitution: equilibrium structures of benzonitrile and phenylacetylene. J Phys Chem A 117(48):1296912982

824 CAS RN: 1374259-90-1 MGD RN: 474474 MW supported by ab initio calculations

1,2-Difluorobenzene – ethyne (1/1) o-Difluorobenzene – acetylene (1/1) C8H6F2 Cs F

H

a

a

Distances X1…X2 b X1…X3 c rd

r0 [Å] 3.8515(20) 3.7429(82) 2.725(28)

rs [Å] 3.8227(18)

Angles X1…X2…X3 C(8)…X1…X2 C(8)…X1…X3 X1…X3…X2

τ0 [deg] a

τs [deg] a

76.08(15) 141.5(13) 130.4(26) 92.8(9)

72.43(20) 135.8(11)

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit. X1 is the midpoint of C(7)≡C(8), X2 is the midpoint of C(3)…C(6).

F

C

C

H

722 c d

9 Molecules with Seven to Nine Carbon Atoms

X3 is the center-of-mass of the difluorobenzene subunit. Distance between H(1) and the ring plane.

The rotational spectra of the binary complex of 1,2-difluorobenzene with acetylene were recorded in a supersonic jet by Balle-Flygare type and chirped-pulse FTMW spectrometers in the frequency region between 6 and 20 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, five 13C and D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Moreover, the partial rs structure was determined. Akmeemana AG, Kang JM, Dorris RE, Nelson RD, Anderton AM, Peebles RA, Peebles SA, Seifert NA, Pate BH (2016) Effect of aromatic ring fluorination on CH⋅⋅⋅π interactions: microwave spectrum and structure of the 1,2-difluorobenzene⋅⋅⋅acetylene dimer. Phys Chem Chem Phys 18(35):24290-24298

825 CAS RN: 1801173-56-7 MGD RN: 467016 GED augmented by DFT computations

N-Methyl-N-[[tris(1,1,2,2,2-pentafluoroethyl)silyl]oxy]methanamine C8H6F15NOSi C1 (I) CH3 F

Bonds Si–C(12) Si–C(13) Si–C(14) Si–O O–N N–C(4) N–C(5) C(12)–C(15) C(13)–C(18) C(14)–C(21)

re [Å] a 1.966 1.973 1.971 1.746 1.495 1.472 1.471 1.534 1.535 1.537

Bond angles Si–C(12)–C Si–C(13)–C Si–C(14)–C Si–O–N C–N–C O–N–C(4) O–N–C(5)

θe [deg] a

Dihedral angles C(15)–C–Si–O C(18)–C–Si–O C(21)–C–Si–O C(12)–Si–O–N C(13)–Si–O–N C(14)–Si–O–N Si–O–N–C(4) Si–O–N–C(5)

τe [deg] a

116.6 117.2 120.4 105.9 113.2 103.6 104.0

-13.6 -103.0 -116.2 176.9 -73.3 67.9 -121.4 120.1

Reproduced with permission from The Royal Society of Chemistry.

N

F

O

F

F

CH3 F

Si

F F

F

F F F F

F F

F

9 Molecules with Seven to Nine Carbon Atoms a

723

Selected parameters derived from Cartesian coordinates.

Five conformers differing in the orientations of the C2F5 groups were predicted by B3LYP/6-31G(d,p) computations. The lowest energy conformer, I, is lower in energy than all other conformers by up to 2.1 kcal mol–1. The GED experiment was carried out at Tnozzle of 266 and 296 K for the long and short nozzle-to-plate distances. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were estimated by MD simulation at the B3LYP/6-31G(d,p) level of theory. Only effective structural parameters could be determined for the model of a single conformer (I). A failure of determining the accurate structure proved complexity and floppiness of the title molecule. Waerder B, Steinhauer S, Bader J, Neumann B, Stammler HG, Vishnevskiy YV, Hoge B, Mitzel NW (2015) Pentafluoroethyl-substituted α-silanes: model compounds for new insights. Dalton Trans 44 (29):13347-13358

826 CAS RN: 1467768-46-2 MGD RN: 411973 MW supported by ab initio calculations

Fluorobenzene – ethyne (1/1) Fluorobenzene – acetylene (1/1) C8H7F Cs F

H

a

Distance Rcm b

r0 [Å] 4.180(10)

rs [Å] 4.159(20)

Angles

θ0 [deg] a

θs [deg] a

c

φ θd

97.0(10) 170.0(30)

C

C

H

a

95.5(22) 172.9(30)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Distance between centers of mass of the monomer subunits. c Angle between Rcm and extension of the C–F bond. d Angle between Rcm and the C∞ axis of the ethyne subunit. b

The rotational spectra of the binary complex of fluorobenzene with acetylene were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The partial r0 structure of the carbon skeleton was determined from the ground-state rotational constants of seven isotopic species (main and six 13C) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Moreover, the partial rs structure was determined. Ulrich NW, Songer TS, Peebles RA, Peebles SA, Seifert NA, Pérez C, Pate BH (2013) Effect of aromatic ring fluorination on CH⋅⋅⋅π interactions: rotational spectrum and structure of the fluorobenzene⋅⋅⋅acetylene weakly bound dimer. Phys Chem Chem Phys 15(41):18148-18154

827 CAS RN: 586-39-0 MGD RN: 904128 GED supplemented by QC computations

1-Ethenyl-3-nitrobenzene 3-Nitrostyrene C8H7NO2 Cs (syn) Cs (anti)

724

9 Molecules with Seven to Nine Carbon Atoms

Bonds C–C(ring) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(1)–C(11) C(11)–C(12) C–N C–H N=O

re [Å] a 1.391(1) b 1.397 c 1.382 c 1.389 c 1.389 c 1.391 c 1.399 c 1.477(5) 1.333(7) 1.463(5) 1.091(7) d 1.227(3)

Bond angle O=N=O

θe [deg] a,e

O N

O

CH2

syn

124.5(7)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 2σ values. Average value. c Differences between the C–C bond lengths in the ring were assumed at the values from MP2_full/cc-pVTZ computation. d Mean value. e Bond angles in the benzene ring and all C–C–H angles were assumed at the value from calculation as indicated above. b

Two conformers, syn and anti, with the C(2)–C(1)–C(11)=C(12) torsional angles of 0 and 180°, respectively, were predicted by B3LYP/6-311+G* and MP2_full/cc-pVTZ computations. The energy difference between these conformers was calculated to be 56 cm-1 (MP2); the syn conformer is slightly preferable. The GED experiment was carried out at Tnozzle = 303 K. Rotations of the nitro and vinyl groups around the C–N and C(1)–C(11) bonds, respectively, were described by a dynamic model with 342 pseudo-conformers using PES from the computations. This work is the first application of the two-dimensional large-amplitude motion model in the GED analysis. The ratio of the conformers was estimated to be syn : anti = 50(20) : 50(20) (in %) being in agreement with theoretical predictions. Vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were calculated with scaled quadratic and cubic force constants from QC calculations by taking into account non-linear kinematic effects. Structural parameters were presented for the syn conformer. Kovtun DM, Kochikov IV, Tarasov YI (2015) Electron diffraction analysis for the molecules with multiple large-amplitude motions. 3-Nitrostyrene-a molecule with two internal rotors. J Phys Chem A 119 (9):1657-1665

828 CAS RN: 264146-43-2 MGD RN: 414951 MW supported by ab initio calculations

Benzene – ethyne (1/1) Benzene – acetylene (1/1) C 8H 8 C6v (assumed) H

Distances Rcm b rc

a

r0 [Å] 4.1546(1) 2.4921(1)

a

rs [Å] 4.1320(15) 2.4717(7)

C

C

H

9 Molecules with Seven to Nine Carbon Atoms

725

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. Distance between the centers of mass of the monomer subunits. c Hydrogen bond with π-electron system of of the benzene subunit. b

The rotational spectra of the binary complex of benzene with acetylene were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 20 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, three 13C and D) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Moreover, the partial rs structure was determined. Ulrich NW, Seifert NA, Dorris RE, Peebles RA, Pate BH, Peebles SA (2014) Benzene⋅⋅⋅acetylene: a structural investigation of the prototypical CH⋅⋅⋅π interaction. Phys Chem Chem Phys 16(19):8886-8894

829 CAS RN: 1425-58-7 MGD RN: 487906 MW augmented by DFT calculations

[1,2]Azaborino[1,2-a][1,2]azaborine 4a-Azonia-8a-boratanaphthalene C8H8BN C2v B

Bonds B–N N–C(2) C(2)=C(1) C(1)–C(4) C(4)=C(3) C(3)–B

r0 [Å] a 1.470 1.391 1.352 1.435 1.384 1.510

Bond angles N–C(8)=C(13) C(8)=C(13)–C(12) C(13)–C(12)=C(9) C(12)=C(9)–B C(9)–B–N B–N–C(8)

θ0 [deg]

N

122 122 120 120 116 120

Reproduced with permission of AIP Publishing.

a

Uncertainties for coordinates of the heavy atoms was estimated to be 0.005 Å.

The rotational spectra of the title compound were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 2 and 10.4 GHz. The partial r0 structure was determined from the ground-state rotational constants of seven isotopic species (main, 10B, 15N and four 13C); the C–H distances were constrained to their B3LYP/aug-cc-pVTZ equilibrium values.

726

9 Molecules with Seven to Nine Carbon Atoms

Pejlovas AM, Daly AM, Ashe AJ, Kukolich SG (2016) Microwave spectra, molecular structure, and aromatic character of 4a,8a-azaboranaphthalene. J Chem Phys 144(11):114303/1-114303/10 [http://dx.doi.org/10.1063/1.4943882]

830 CAS RN: 1028843-99-3 MGD RN: 210585 MW supported by ab initio calculations

Ethynylbenzene – water (1/1) Phenylacetylene – water (1/1) C8H8O C1 C

C

H

O H

H

a

Distances O(15)…C(7) H(2)…X b H(1)…O(15)

r0 [Å] 3.423(4) 2.477 c 2.544 c

Angles O(15)…C(7)≡C(8) H(2)–O(15)…C(7) C(3)–H(1)…O(15) O(15)–H(2)…X

θ0 [deg] a

Dihedral angles O(15)…C(7)≡C(8)…C(3) H(2)–O(15)…C(7)…C(3) H(2)–O(15)…H(1)–C(3)

τ0 [deg] a

80.4(1) 25(3) 145.6 c 154.9 c

-11.1(6) 226(12) 45.8 c

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit. X is the midpoint of the C≡C bond. c Dependent parameter.

b

The rotational spectrum of the binary complex of phenylacetylene with water was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 3 and 12.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 18 O, two D and D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Goswami M, Arunan E (2011) Microwave spectroscopic and theoretical studies on the phenylacetylene⋅⋅⋅H2O complex: C-H⋅⋅⋅O and O-H⋅⋅⋅π hydrogen bonds as equal partners. Phys Chem Chem Phys 13(31):14153-14162

831 CAS RN: MGD RN: 211361 MW supported by ab initio calculations

Distance Rcm b

r0 [Å] a 3.74

Ethynylbenzene – hydrogen sulfide (1/1) C 8H 8S Cs C

C

H

S H

H

9 Molecules with Seven to Nine Carbon Atoms

727

Copyright 2011 with permission from Elsevier.

a b

Uncertainty was not given in the original paper. Distance between the centers of mass of both subunits.

The rotational spectra of the binary complex were recorded by a pulsed-nozzle FTMW spectrometer in the spectral region between 3 and 19 GHz. The H2S subunit was found to be located over the phenyl ring π cloud and shifted from the phenyl ring center towards the acetylene group. The r0 structure was determined from the ground-state rotational constants of five isotopic species (main, 34S, two D and D2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Goswami M, Arunan E (2011) Microwave spectrum and structure of C6H5CCH⋅⋅⋅H2S complex. J Mol Spectrosc 268(1-2):147-156

832 CAS RN: 2439-77-2 MGD RN: 513732 GED augmented by QC computations

Bonds C(8)=O(9) C(8)–N C(2)–O(7) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(1)–C(8) C(10)–O(7) N–H C–H

rh1 [Å] a 1.191(5) b 1.364(10) b 1.376(10) c 1.421(4) b 1.410(8) d 1.399(9) d 1.399(9) d 1.403(8) d 1.407(8) d 1.493(10) d 1.413(13) b 1.008(20) b,e 1.106(7) b,e

Bond angles C(1)–C(8)=O(9) C(1)–C(8)–N C(1)–C(2)–O(7) C(6)–C(1)–C(8) C(1)–C(2)–C(3) C(2)–C(1)–C(6) C(1)–C(6)–C(5) C–C–H C–N–H(1) C–N–H(2) C(2)–O(7)–C(10) O(7)–C(10)–H

θh1 [deg] a

2-Methoxybenzamide o-Anisamide C8H9NO2 Cs (I) C1 (II)

I

121.8(9) b 115.5(10) b 116.1(16) b 114.8(11) b 119.2(5) b 118.6(5) f 121.0(5) f 119.6(9) b,e 116.9(9) 122.5(10) 123.2(17) b 109.4(9) b,e II

728

Dihedral angles C(2)–C(1)–C(8)=O(9) C(1)–C(8)–N–H(1) C(1)–C(2)–O(7)–C(10) C(2)–O(7)–C(10)–H(5)

9 Molecules with Seven to Nine Carbon Atoms

I -180 g,h -180 g,i -180 g,j -180 g,k

τh1 [deg] a

II -158 g -174 g 105(4) b -179 k,l

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Independent parameter. c Flexibly restrained to C(8)–N. d Flexibly restrained to C(1)–C(2). e Average value. f Flexibly restrained to C(1)–C(2)–C(3). g Assumed at the value from MP2/6-311+G(d,p) calculation. h 0° when C(8)=O(9) is eclipsing C(1)–C(2). i 0° when N–H(2) is eclipsing C(1)–C(2). j 0° when O(7)–C(10) is eclipsing C(1)–C(2). k 0° when O(7)–C(2) is eclipsing C(10)–H(5). l Assumed. b

The GED experiment was carried out at Tnozzle ≈ 403 K. The title compound was found to exist as a mixture of two conformers, I and II, characterized by the antiperiplanar and anticlinal C(1)–C(2)–O(7)–C(10) torsional angles, respectively. The main conformer (I) was determined to be present in the amount of 89(4) %. Presence of intramolecular hydrogen bond H(2)…O(7) was indicated. The structural parameters for the conformer II were constrained to the values of conformer I by means of differences from MP2/6-311+G(d,p) calculation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from HF/6-311+G(d,p) computation. Aarset K, Page EM, Rice DA (2013) Hydrogen bonding in the gas-phase: The molecular structures of 2hydroxybenzamide (C7H7NO2) and 2-methoxybenzamide (C8H9NO2), obtained by gas-phase electron diffraction and theoretical calculations. J Phys Chem A 117 (14):3034-3040

833 CAS RN: 95-47-6 MGD RN: 437177 MW augmented by QC calculations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(1)–C(7) C(7)–H(1) C(7)–H(2) C(3)–H C(4)–H

1,2-Dimethylbenzene o-Xylene C8H10 C2v CH3

r0 [Å] a 1.434(14) 1.3946(69) 1.3969(69) 1.388(10) 1.4995(42) 1.0790(25) 1.1014(12) 1.0843(38) 1.0797(41)

r (m2) [Å] a 1.398(10) 1.3843(43) 1.3967(35) 1.3849(62) 1.5119(30) 1.0793(14) 1.0910(22) 1.0882(20) 1.0853(24)

r see [Å] a 1.3966(18) 1.3929(16) 1.3975(18) 1.3892(66) 1.5075(16) 1.0886(18) 1.0894(15) 1.0796(17) 1.0795(17)

CH3

9 Molecules with Seven to Nine Carbon Atoms

729

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–C(7) C(1)–C(7)–H(1) H(1)–C(7)–H(2) C(1)–C(7)–H(2) H(2)–C(7)–H(3) C(2)–C(3)–H C(4)–C(3)–H C(3)–C(4)–H C(5)–C(4)–H

θ0 [deg] a

θ (m2) [deg] a

θ see [deg] a

Dihedral angles C(6)–C(1)–C(7)–H(2) C(2)–C(1)–C(7)–H(2)

τ0 [deg] a

τ (m2) [deg] a

τ see [deg] a

118.66(32) 121.67(39) 119.68(19) 120.35(30) 110.65(31) 108.55(18) 111.21(21) 106.53(17) 117.89(46) 120.45(35) 119.82(58) 120.51(46)

120.72(22) 59.28(22)

119.47(21) 121.03(23) 119.50(11) 120.61(16) 111.00(17) 108.63(10) 111.55(17) 105.24(28) 119.07(31) 119.90(21) 119.63(33) 120.87(26)

121.31(14) 58.69(14)

119.74(9) 120.45(15) 119.81(14) 120.24(10) 110.78(16) 108.04(21) 111.44(12) 106.94(26) 119.67(18) 119.89(24) 119.97(18) 120.22(22)

120.32(19) 59.69(19)

Copyright 2013 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of o-xylene was recorded for the main and partially deuterated isotopic species by Starkmodulated MW spectrometers in the frequency region between 7 and 36 GHz. The spectra of three singly substituted 13C isotopic species (in natural abundance) were measured by a MW-MW double resonance spectrometer with a pump frequency range between 7 and 18 GHz and a signal range between 23 and 36 GHz. The r0 and r (m2) structures were determined from the ground-state rotational constants of fourteen isotopic species (main, four 13C, four D, two D2, D3, D10 and 13C/D10). The semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the B3LYP/6311+G(3df,2pd) harmonic and anharmonic (cubic) force constants; the semiexperimental equilibrium rotational constants of the non-deuterated species were supplemented by the values of structural parameters containing hydrogen atoms, which were adopted from the calculated structure of CCSD(T)_ae/cc-pwCVQZ quality. Vogt N, Demaison J, Geiger W, Rudolph HD (2012) Microwave spectrum and equilibrium structure of o-xylene. J Mol Spectrosc 288:38-45

834 CAS RN: 91-16-7 MGD RN: 211508 GED augmented by QC computations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4)

1,2-Dimethoxybenzene 2-Methoxyanisole C8H10O2 C2v (anti-anti) C1 (anti-gauche) C2 (gauche-gauche)

rh1 [Å] a,b anti-gauche anti-anti 1.411(10) 1 1.417(10) 1 1.395(10) 1 1.390 1 1 1.396(10) 1.399 1

O CH3

O

CH3

730

C(4)–C(5) C(5)–C(6) C(1)–C(6) C(1)–O(7) C(2)–O(8) C(9)–O(7) C(10)–O(8) C–H Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–O(7) C(1)–C(2)–O(8) C(1)–O(7)–C(9) C(2)–O(8)–C(10) C(4)–C(5)–C(6) C(1)–C(6)–C(5) C(2)–C(1)–C(6) C–C–H O–C–H(1) O–C–H(4) O–C–H(2,3,5,6) Dihedral angles C(2)–C(1)−O(7)–C(9) C(1)–C(2)−O(8)–C(10)

9 Molecules with Seven to Nine Carbon Atoms

1.387(10) 1 1.395(10) 1 1.388(10) 1 1.375(9) 2 1.366(9) 2 1.431(9) 2 1.421(9) 2 1.105(6) d

1.404(36) c 1.363(9) 2 1.419 2 1.105(6) d

θh1 [deg] a,b

anti-gauche 119.4(5) 3 120.6(5) 3 120.5(5) 3 121.1(7) 4 115.9(7) 4 115.9(7) 4 118.1(7) 4 118.6(16) c 122.2(27) c 118.7(16) c 117.8-120.2 e 106.2 e 106.0 e 110.6-111.6 e

anti-gauche 65.2(55) 177.6 e

anti-anti

anti-anti 119.6(5) 3 120.7 3 119.7(10) c 115.3(7) 4 117.9 4

119.4-120 e 106.0 e 111.6 e

τh1 [deg] a

anti-anti 180.0 e 180 e

Copyright 2009 with permission from Elsevier.

anti-gauche Parenthesized uncertainties in units of the last significant digit are 3σ values. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from B3LYP/cc-pVTZ computation. c Dependent parameter. d Average value. e Assumed at the value from computation as indicated above. a

The GED experiment was carried out at Tnozzle = 333 K. The title compound was found to exist as a mixture of three conformers, characterized by the gauche and/or anti positions of the methoxy groups with respect to the C(1)–C(2) bond. The GED data were well reproduced by the mixture of the conformers in the ratio anti-anti : anti-gauche : gauche-gauche = 50(12) : 36(16) : 14 (in %), being in agreement with results of calculations at the MP2 and B3LYP levels of theory in conjunction with cc-pVTZ basis set. The structural parameters were presented for the dominant conformer (anti-anti). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Dorofeeva OV, Shishkov IF, Karasev NM, Vilkov LV, Oberhammer H (2009) Molecular structures of 2methoxyphenol and 1,2-dimethoxybenzene as studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 933(1-3):132-141.

835

1,3-Dimethoxybenzene

9 Molecules with Seven to Nine Carbon Atoms

731

CAS RN: 151-10-0 MGD RN: 211300 GED augmented by QC computations

Bonds

m-Dimethoxybenzene C8H10O2 Cs (syn-anti) C2v (anti-anti) C2v (syn-syn)

syn-anti 1.393(4) 1 1.405(4) 1 1.396(4) 1 1.402(4) 1 1.385(4) 1 1.406(4) 1 1.366(6) 2 1.368(6) 2 1.422(6) 2 1.422(6) 2 1.116(6) 3,c

C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(1)–O(7) C(3)–O(8) C(9)–O(7) C(10)–O(8) C–H Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–O(7) C(2)–C(3)–O(8) C(1)–O(7)–C(9) C(3)–O(8)–C(10) C(4)–C(5)–C(6) C(1)–C(6)–C(5) C(2)–C(1)–C(6) C–C–H O–C–H(1) O–C–H(2) Dihedral angles C(2)–C(1)–O(7)–C(9) C(2)–C(3)–O(8)–C(10)

syn-anti 119.5(1) 4 120.4(1) 4 118.4(1) 4 124.1(7) 5 114.9(7) 5 118.6(7) 5 118.5(7) 5 122.6(7) d 117.8(10) d 121.2(7) d 117.9-121.8 e 106.0 e 111.5 e

syn-anti 0.0 180.0

rh1 [Å] a,b anti-anti syn-syn 1.396(4) 1 1.403(4) 1

1.394(4) 1 1.403(4) 1 1.368(6) 2

1.392 1 1.399 1 1.368(6) 2

1.422(6) 2

1.421 2

1.122(9) 3,c

1.116(8) 3,c

θh1 [deg] a,b

anti-anti 120.0(2) 4 120.0(2) 4

syn-syn 119.0(2) 4 120.4 4

115.5(7) 5

123.6(7) 5

118.6(7) 5

119.05

120.5(10) d 119.7(7) d

119.9(10) 120.2(7) d

119.4-121.4 e 106.0 e 111.6 e

119.0-120.4 e 106.0 e 111.6 e

τh1 [deg] e

anti-anti 180.0 180.0

O

O

H3C

CH3

syn-syn 0.0 0.0

Copyright 2009 with permission from Elsevier.

syn-anti a

anti-anti

Parenthesized uncertainties in units of the last significant digit are 3σ values.

syn-syn

732

9 Molecules with Seven to Nine Carbon Atoms

b

Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from B3LYP/cc-pVTZ computation. c Average value. d Dependent parameter. e Assumed at the value from computation as indicated above. The GED experiment was carried out at Tnozzle = 344 K. The title compound was found to exist as a mixture of three conformers, characterized by the synperiplanar and/or antiperiplanar positions of the methoxy groups with respect to the C(2)–C bonds. The ratio of these conformers was determined to be syn-anti : anti-anti : syn-syn = 46(19) : 31(15) : 23 (in %), being in agreement with predictions at the MP2 and B3LYP levels of theory. The methyl groups were assumed to have staggered conformation with respect to the C(2)–C(1,3) bonds. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Dorofeeva OV, Shishkov IF, Rykov AN, Vilkov LV, Oberhammer H (2010) Molecular structure of 1,3dimethoxybenzene as studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 978(1-3):35-40

836 CAS RN: 121-69-7 MGD RN: 925394 MW supported by ab initio calculations

N,N-Dimethylbenzenamine N,N-Dimethylaniline C8H11N Cs CH3

N

a

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–N N–C(7)

rs [Å] 1.378 1.401 1.396 1.441 1.424

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(6)–C(1)–C(2) C(2)–C(1)–N C(1)–N–C(7)

θs [deg] a

CH3

118.7 121.2 118.2 122.0 119.0 119.5

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Uncertainties were not given in the original paper.

The rotational spectrum of N,N-dimethylaniline was recorded in a pulsed supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 18 GHz. The substitution coordinates of the heavy-atom skeleton were determined from the ground-state rotational constants of seven isotopic species (main, five 13C and 15N). The presented partial rs structure is derived in this book from these coordinates.

9 Molecules with Seven to Nine Carbon Atoms

733

Bird RG, Neill JL, Alstadt VJ, Young JW, Pate BH, Pratt DW (2011) Ground state 14N quadrupole couplings in the microwave spectra of N,N-dimethylaniline and 4,4-dimethylaminobenzonitrile. J Phys Chem A 115(34):9392-9398

837 CAS RN: 822-93-5 MGD RN: 141077 GED augmented by ab initio computations

Bonds C(2)=C(1) C(1)–C(3) C(1)–C(6) C(3)–C(4) C(3)–C(5) C(4)–C(5) C(6)–C(7) C(6)–C(8) C(7)–C(8) C–H a Bonds C(1)=C(2) C(1)–C(3) C(1)–C(6) C(3)–C(4) C(3)–C(5) C(4)–C(5) C(6)–C(7) C(6)–C(8) C(7)–C(8) C–H a Angles C(2)=C(1)–C(3) C(2)=C(1)–C(6) C(3)–C(1)–C(6) C(1)–C(3)–C(4) C(1)–C(3)–C(5) C(1)–C(6)–C(7) C(1)–C(6)–C(8) C(4)–C(3)–C(5) C(3)–C(4)–C(5) C(3)–C(5)–C(4) C(7)–C(6)–C(8) C(6)–C(7)–C(8) C(6)–C(8)–C(7) C(1)–C(2)–H a C(1)–C(3,6)–H a C–C–H (ring) a

1,1'-Ethenylidenebiscyclopropane 1,1-Dicyclopropylethene C8H12 C1 (syn-gauche) C2 (gauche-gauche) Cs (gauche-gauche–)

syn-gauche 1.350 1.490 1.494 1.523 1.525 1.555 1.526 1.513 1.498 1.114

rg [Å] gauche-gauche 1.348 1.494 1.494 1.525 1.511 1.493 1.525 1.511 1.493 1.114

gauche-gauche– 1.348 1.494 1.494 1.512 1.524 1.535 1.524 1.512 1.532 1.114

syn-gauche 1.339(7) 1 1.484(2) 2 1.489(2) 2 1.499(2) 2 1.499(2) 2 1.515 d 1.501(2) 2 1.493(2) 2 1.459 d 1.078(4) 3

rα [Å] b,c gauche-gauche 1.339(7) 1 1.488(2) 2 1.488(2) 2 1.500(2) 2 1.487(2) 2 1.458 d 1.500(2) 2 1.487(2) 2 1.458 d 1.081(4) 3

gauche-gauche– 1.337(7) 1 1.482(2) 2 1.482(2) 2 1.467(2) 2 1.471(2) 2 1.438 d 1.471(2) 2 1.467(2) 2 1.435 d 1.049(4) 3

syn-gauche 121.8(10) 4 124.0(10) 4 114.2 d 123.9(15) 5 122.7(13) 6 121.6(15) 5 123.3(13) 6 60.7 d 59.7 d 59.6 d 58.3 d 60.6 d 61.1 d 121.5(16)7 115.3(16)7 117.6(16)7

θα [deg] b,c

gauche-gauche 124.8(10) 4 124.8(10) 4 110.5 d 121.2(15) 5 124.0(13) 6 121.2(15) 5 124.0(13) 6 58.4 d 60.3 d 61.2 d 58.4 d 60.3 d 61.2 d 121.6(16)7 114.9(16)7 117.8(16)7

gauche-gauche– 124.7(10) 4 124.7(10) 4 110.6 d 125.6(15) 5 120.5(13) 6 121.9(15) 5 124.3(13) 6 58.6 d 60.8 d 60.6 d 58.5 d 60.7 d 60.9 d 121.6(16)7 114.7(16)7 117.9(16)7

CH2

734

Dihedral angles C(2)=C(1)–C(3)–C(4) C(2)=C(1)–C(3)–C(5) C(2)=C(1)–C(3)–H C(2)=C(1)–C(6)–C(7) C(2)=C(1)–C(6)–C(8) C(2)=C(1)–C(6)–H

9 Molecules with Seven to Nine Carbon Atoms

syn-gauche 147.2 d -138.4 d 2.0 d -80.1(90) 8 -9.6(90) 8 139.7(90) 8

τα [deg] b,c

gauche-gauche -80.5(90) 8 -9.7(90) 8 139.7(90) 8 -80.5(90) 8 -9.7(90) 8 139.7(90) 8

gauche-gauche– 8.6(90) 8 79.8(90) 8 -140.0(90) 8 -8.6(90) 8 140.0(90) 8

Copyright 2012 with permission from Elsevier.

syn-gauche

gauche-gauche

gauche-gauche– a

Average value. Parenthesized uncertainties in units of the last significant digit are 3σ values. c Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from MP2_full/aug-cc-pVTZ calculation; uncertainties of the parameters in each group were estimated to be equal. d Dependent parameter. b

The GED experiment was carried out at Tnozzle = 293 K. Three conformers, syn-gauche, gauche-gauche and gauche-gauche–, characterized by the synclinal and/or ±anticlinal C(2)=C(1)–C–H torsional angles, were found to be present in amounts of 36(14), 38(27) and 26 %, respectively. Harmonic vibrational corrections to the experimental internuclear distances, ∆rα = ra – rα, were calculated using scaled quadratic force constants from MP2/6-31G(d,p) calculation. Kuze N, Ohno C, Morisaki S, Sugawara Y, Tamagawa K, Konaka S (2012) A study of the structure and conformation of 1,1-dicyclopropylethene by gas electron diffraction and ab initio calculations. J Mol Struct 1014:26-31

838 CAS RN: 931-48-6 MGD RN: 198832 MW augmented by QC calculations

Ethynylcyclohexane Cyclohexylacetylene C8H12 Cs (equatorial) Cs (axial)

9 Molecules with Seven to Nine Carbon Atoms

735

equatorial r0 [Å] a 1.532(3) 1.544(3) 1.541(3) 1.462(3) 1.098(2) 1.096(2) 1.099(2) 1.096(2) 1.098(2) 1.095(2) 1.100(2) 1.210(3) 1.065(3)

axial r0 [Å] a 1.537(3) 1.534(3) 1.545(3) 1.468(3) 1.099(2) 1.096(2) 1.097(2) 1.096(2) 1.098(2) 1.095(2) 1.097(2) 1.212(3) 1.065(3)

Bond angles C(10)–C(1)–C(2) C(1)–C(2)–C(3) C(4)–C(3)–C(2) C(3)–C(4)–C(3') C(6)–C(4)–C(3) C(2)–C(1)–H(2) C(2)–C(1)–H(1) H(2)–C(1)–H(1) C(1)–C(2)–H(3) C(1)–C(2)–H(4) C(3)–C(2)–H(3) C(3)–C(2)–H(4) H(3)–C(2)–H(4) C(4)–C(3)–H(6) C(4)–C(3)–H(7) C(2)–C(3)–H(6) C(2)–C(3)–H(7) H(6)–C(3)–H(7) C(3)–C(4)–H(5) C(6)–C(4)–H(5) C(4)–C(6)≡C(7) C(6)≡C(7)–H(8)

θ0 [deg] a

θ0 [deg] a

Dihedral angle C(1)–C(2)–C(3)–C(4)

τ0 [deg] a

τ0 [deg] a

Bonds C(1)–C(2) C(2)–C(3) C(4)–C(3) C(4)–C(6) C(1)–H(2) C(1)–H(1) C(2)–H(3) C(2)–H(4) C(3)–H(6) C(3)–H(7) C(4)–H(5) C(6)≡C(7) C(7)–H(8)

110.8(5) 111.0(5) 110.2(5) 111.1(5) 110.7(5) 109.1(5) 110.4(5) 107.0(5) 109.3(5) 110.5(5) 109.7(5) 109.4(5) 106.9(5) 108.4(5) 109.5(5) 110.3(5) 111.3(5) 107.1(5) 108.1(5) 108.1(5) 179.9(5) 179.9(5)

56.7(10)

C

111.2(5) 111.2(5) 112.0(5) 110.5(5) 110.3(5) 109.1(5) 110.2(5) 106.9(5) 109.4(5) 111.2(5) 109.0(5) 109.8(5) 107.0(5) 108.0(5) 109.7(5) 108.1(5) 111.4(5) 107.5(5) 109.2(5) 107.3(5) 179.8(5) 179.8(5)

55.3(10)

Copyright 2015 with permission from Elsevier.

a

Parenthesized estimated uncertainties in units of the last significant digit.

equatorial

axial

C

H

736

9 Molecules with Seven to Nine Carbon Atoms

The rotational spectrum of the title compound was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 11 and 21 GHz. The observed lines were assigned to two conformers, chair-equatorial and chair-axial. The r0 structure of each conformer was determined by fitting the MP2_full/6-311+G(d,p) structure to the determined ground-state rotational constants of one isotopic species. Both conformers were also identified in the temperature-dependent IR vibrational spectra. The percentage of the equatorial conformer was estimated to be 55(3) % at ambient temperature. Durig JR, Ward RM, Conrad AR, Tubergen MJ, Nelson KG, Gounev TK (2010) Microwave, infrared, and Raman spectra, r0 structural parameters, conformational stability, and vibrational assignment of ethynylcyclohexane.” J Mol Struct 975(1-3):5-16

839 CAS RN: 532-24-1 MGD RN: 214676 MW supported by ab initio calculations

8-Methyl-8-azabicyclo[3.2.1]octan-3-one Tropinone C8H13NO Cs (equatorial) Cs (axial) H 3C N O

equatorial r0 [Å] a 1.465(2) 1.478(7) 1.548(6) 1.554(4) 1.515(11) 1.224(9)

rs [Å] a 1.460(3) 1.506(19) 1.483(19) 1.552(15) 1.513(16) 1.199(7)

Bond angles C(9)–N(8)–C(1) N(8)–C(1)–C(7) N(8)–C(1)–C(2) C(1)–N(8)–C(5) C(1)–C(2)–C(3) C(2)–C(3)=O C(2)–C(3)–C(4)

θ0 [deg] a

θs [deg] a

Dihedral angles C(9)–N(8)–C(5)–C(6) C(9)–N(8)–C(5)–C(4) N(8)–C(5)–C(4)–C(3) C(5)–C(4)–C(3)=O N(8)–C(5)–C(6)–C(7) C(3)–C(4)–C(5)–C(6)

θ0 [deg] a

Bonds C(9)–N(8) N(8)–C(1) C(1)–C(7) C(1)–C(2) C(2)–C(3) C(3)=O

111.8(2) 106.2(5) 107.1(3) 101.7(5) b 111.1(4) 122.5(12) 116.0(9) b

77.6(3) -164.0(4) -57.1(10) -140.1(14) 25.7(4) b 58.5(6) b

111.8(13) 106.6(13) 105.0(10) 98.9(9) 110.3(9) 122.1(15) 115.8(7)

θs [deg] a

77(2) -162.1(13) -60(2) -143(2) 26.1(18) 56(2)

Reproduced with permission from the PCCP Owner Societies.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

axial r0 [Å] a

rs [Å] a

1.546(6) 1.540(3) 1.532(5)

1.547(19) 1.534(11) 1.522(15)

θ0 [deg] a

θs [deg] a

116.8(2) 101.2(3) 112.5(3) 103.1(3) b 109.5(3)

110.2(14)

113.8(5) b

θ0 [deg] a

-179.50(9) -60.9(2) -57.9(6) -137.6(10) 29.3(8) b 54.6(5) b

θs [deg] a

55.4(13)

9 Molecules with Seven to Nine Carbon Atoms

equatorial

737

axial

The rotational spectra of tropinone were recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 18 GHz. The equatorial and axial conformers differing in locations of the methyl group were identified. The r0 and rs structures of the equatorial and axial conformers were determined from the ground-state rotational constants of eight (main, five13C, 15N and 18O) and five (main and four 13C) isotopic species, respectively. From the relative intensity measurements, the ratio of the conformers was estimated to be eq : ax ≈ 2 : 1, which corresponds to the relative energy of about 2 kJ mol-1. The high barrier between these conformers, estimated at the MP2/6-311++G(d,p) level to be about 40 kJ mol-1, hinders the conformational relaxation in the jet expansion, as was assumed. Cocinero EJ, Lesarri A, Écija P, Grabow JU, Fernández JA, Castaño F (2010) N-Methyl stereochemistry in tropinone: the conformational flexibility of the tropane motif. Phys Chem Chem Phys 12(23):6076-6083 MW augmented by DFT calculations

Cs

Bonds C(3)=O N–C(5) N–C(9) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(7) C(4)–H(ax) C(4)–H(eq) C(5)–H C(6)–H(ax) C(6)–H(eq) C(9)–H(out) C(9)–H(plane)

r see [Å] a 1.2110(15) 1.4712(20) 1.4595(21) 1.5140(19) 1.5300(20) 1.5454(22) 1.5561(74) 1.0889(16) 1.0919(16) 1.0897(16) 1.0891(16) 1.0882(16) 1.0886(16) 1.0977(16)

Bond angles C(2)–C(3)–C(4) C(4)–C(3)=O C(3)–C(4)–C(5) C(4)–C(5)–N C(1)–N–C(5) C(1)–N–C(9) C(4)–C(5)–C(6) C(5)–C(6)–C(7)

θ see [deg] a

114.73(17) 122.61(8) 110.99(15) 107.65(14) 101.79(16) 111.44(11) 110.51(19) 103.61(18)

738

9 Molecules with Seven to Nine Carbon Atoms

C(3)–C(4)–H(ax) C(3)–C(4)–H(eq) C(4)–C(5)–H N–C(9)–H(plane) N–C(9)–H(out) C(5)–C(6)–H(ax) C(5)–C(6)–H(eq)

108.85(26) 108.58(30) 109.98(26) 114.50(25) 109.07(24) 111.40(37) 110.93(37)

Dihedral angles O=C(3)–C(4)–C(5) C(3)–C(4)–C(5)–N C(2)–C(1)–N–C(9) C(3)–C(4)–C(5)–C(6) O=C(3)–C(4)–H(ax) O=C(3)–C(4)–H(eq) C(3)–C(4)–C(5)–H C(5)–N–C(9)–H(plane) C(5)–N–C(9)–H(out) N–C(5)–C(6)–H(ax) N–C(5)–C(6)–H(eq)

τ see [deg] a

-138.29(34) -57.97(20) 165.37(19) 57.22(27) -10.96(40) 108.02(48) -177.50(31) -56.48(11) 64.52(42) 147.15(33) -93.15(34)

Reprinted with permission. Copyright 2012 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The semiexperimental equilibrium structure r see of the equatorial conformer was determined from the previously published experimental ground-state rotational constants of eight isotopic species taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated from the B3LYP/-cc-pVTZ harmonic and anharmonic (cubic) force fields. Demaison J, Craig NC, Cocinero EJ, Grabow JU, Lesarri A, Rudolph HD (2012) Semiexperimental equilibrium structures for the equatorial conformers of N-methylpiperidone and tropinone by the mixed estimation method. J Phys Chem A 116(34):8684-8692

840 CAS RN: 1245696-84-7 MGD RN: 208922 MW augmented by ab initio calculations

Distance N...H(2)

r0 [Å] a 1.955(6)

Angles H(2)…N–C H(2)…N–C–C N–C–C–C

θ0 [deg] a 110.8(2) 42.0(9) 66.8(8)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

Benzeneethanamine – water (1/1) 2-Phenylethylamine – water (1/1) C8H13NO NH2 C1 O

H

H

9 Molecules with Seven to Nine Carbon Atoms

739

The rotational spectra of the binary complex of 2-phenylethylamine with water were investigated by free jet MW spectroscopy in the frequency region between 60 and 78 GHz. The partial r0 structure was determined by adjusting the MP2/6-311++G** structure to the ground-state rotational constants of two isotopic species (main and 18O). Melandri S, Maris A, Giuliano BM, Favero LB, Caminati W (2010) The free jet microwave spectrum of 2phenylethylamine-water. Phys Chem Chem Phys 12(35):10210-10214

841 CAS RN: 1537920-21-0 MGD RN: 418427 MW augmented by ab initio calculations

Distance N…H

7-Azabicyclo[2.2.2]octane – trifluoromethane (1/1) Quinuclidine – trifluoromethane (1/1) C8H14F3N C3v F

r0 [Å] a 2.070(1)

F

N

F

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the binary complex of quinuclidine with trifluoromethane were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 6.5 and 18 GHz. The partial r0 structure was determined from the ground-state rotational constants of two isotopic species (main and D); the remaining structural parameters were fixed at the MP2/6-311++G(d,p) values. Gou Q, Feng G, Evangelisti L, Caminati W (2014) Interaction between freons and amines: the C-H...N weak hydrogen bond in quinuclidine-trifluoromethane. J Phys Chem A 118(4):737-740

842 CAS RN: 24642-79-3 MGD RN: 539298 GED augmented by QC computations

1,1,3,3-Tetramethylcyclobutane C8H16 D2h

Bonds C–H C(1)–C(5) C(1)–C(6) C(1)–C(2)

rg [Å] a 1.105(5) b 1.524(10) 1.524(10) 1.559(11)

Bond angles C(2)–C(1)–C(4) C(1)–C(2)–C(3)

θα [deg] c 87.8(8) 92.2(7)

H 3C

CH3

H 3C

CH3

740

9 Molecules with Seven to Nine Carbon Atoms

C(5)–C(1)–C(6) C(2)–C(1)–C(5) C(2)–C(1)–C(6)

109.3(13) 116.8(8) 114.6(7)

Torsion angle C(1)–C(2)…C(4)–C(3)

τα [deg] 180 d

Reprinted with permission. Copyright 2017 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 2σ values. Average value. c Uncertainties were assumed to be equal to those for θg bond angles. d According to symmetry. b

Two equilibrium structures of the title molecules, namely with C2v symmetry (non-planar ring) and D2h symmetry (planar ring), were predicted by MP2 and B3LYP methods in conjunction with cc-pVTZ basis set. The barrier height for the C2v conformer was estimated to be very small (0.05 kcal mol-1). Considering the dynamics of large-amplitude bending around the C(2)…C(4) line, the D2h conformer was suggested to be preferred by GED. The GED experiment was carried out at room temperature. Vibrational corrections to the experimental internuclear distances, ∆rα = ra − rα, were calculated using harmonic force constants from QC computations. Sandwisch JW, Hedberg L, Hedberg K (2017) Molecular structure, equilibrium conformation, and ringpuckering motion in 1,1,3,3-tetramethylcyclobutane. An electron-diffraction investigation augmented by molecular orbital and normal coordinate calculations. J Phys Chem A 121 (32):6150-6154

843 CAS RN: 2049912-17-4 MGD RN: 497672 MW augmented by ab initio calculations

1,4,7,10-Tetraoxacyclododecane – water (1/1) 12-Crown-4-ether – water (1/1) C8H18O5 C1 O

Distances O(1)–C(2) C(2)–C(3) O(w)–H(w) O(1)...H(w) O(1)...O(w) H(a)...O(w) c H(b)...O(w) d C(2)–H(1) C(2)–H(1) C(3)–H(3) C(3)–H(4)

r0 [Å] a 1.431(23) 1.524(68) 0.965 b 1.869(43) 2.808(57) 2.828(58) 2.819(45) 1.096 b 1.099 b 1.094 b 1.102 b

Angles O(1)–C(2)–C(3) C(2)–C(3)–O(4) C(3)–O(4)–C(5) O(1)–C(2)–H(1) O(1)–C(2)–H(2)

θ0 [deg] a

111.36(84) 108.3(23) 114.2(34) 106.79 b 110.81 b

O

O H O

O

H

9 Molecules with Seven to Nine Carbon Atoms

C(2)–C(3)–H(3) C(2)–C(3)–H(4) H(w)–O(w)–H(n) H(w)–O(w)…O(1)

108.73 b 109.53 b 104.8 b 10.78 b

Dihedral angles O(w)…O(1)–C(2)–C(3) O(4)–C(3)–C(2)–O(1) C(2)–C(3)–O(4)–C(5) C(3)–O(4)–C(5)–C(6) H(1)–C(2)–O(1)–C(12) H(2)–C(2)–O(1)–C(12) H(3)–C(3)–C(2)–O(1) H(4)–C(3)–C(2)–O(1) H(w)–O(w)…O(1)–C(2) H(n)–O(w)–H(w)…O(1)

τ0 [deg] a

741

-113.2(43) -70.9 b 158.1 b -94.77 b -147.14 b -28.94 b 49.03 b 168.3 b -18.90 b 168.49 b

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit. Constrained to MP2/6-311++G(d,p) value. c H at C(9). d H at C(11). b

The rotational spectra of the binary complex of 12-crown-4-ether with water were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8 GHz. Two conformers were observed. For the most stable conformer, in which the macrocyclic ring has S4 symmetry, eight 13C isotopic species were studied in natural abundance, whereas one singly 18O substituted species was investigated in an isotopically enriched water sample. The partial r0 structure was determined from the ground-state rotational constants of ten isotopic species (main, eight 13C and 18O). Pérez C, López JC, Blanco S, Schnell M (2016) Water-induced structural changes in crown ethers from broadband rotational spectroscopy. J Phys Chem Lett 7(20):4053-4058

844 CAS RN: 2049912-21-0 MGD RN: 497856 MW augmented by ab initio calculations

1,4,7,10-Tetraoxacyclododecane – water (1/2) 12-Crown-4-ether – water (1/2) C8H20O6 C1 O

O

O

Distance O(1)…O(2)

rs [Å] a 2.7794(35)

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit.

H O

O

H

2

742

9 Molecules with Seven to Nine Carbon Atoms

The rotational spectra of the ternary complex of 12-crown-4-ether with water were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8 GHz. The partial rs structure was determined from the ground-state rotational constants of three isotopic species (main and two 18O). Pérez C, López JC, Blanco S, Schnell M (2016) Water-induced structural changes in crown ethers from broadband rotational spectroscopy. J Phys Chem Lett 7(20) 4053-4058

845 CAS RN: 66778-04-9 MGD RN: 362704 GED augmented by ab initio computations

N2,N2,N3,N3,N5,N5,N6,N6-Octamethyl-1,4,2,3,5,6-dithiatetraborinane Tetrakis(dimethylamino)-1,4,2,3,5,6-dithiatetraborinane C8H24B4N4S2 D2 CH3

CH3

N

Bonds S…S S–B B–N C–N C–H B(3)–B(4)

ra3,1 [Å] a 3.899(9) 1.859(2) 1.407(5) 1.463(2) b 1.097(3) b,c 1.733(8) d

Bond angles B(3)–N(7)–C(11) B(3)–N(7)–C(12) N–C–H B–S–B B(3)–B(4)–N(8) S(2)–B(3)–B(4)

θa3,1 [deg] a

Dihedral angles N–B–S...S C(11)–N–B–S B(3)–S...S–B(4) H–C(11)–N–B(3) H–C(12)–N–B(3) B(5)–S(1)–B(4)–B(3) S(2)–B(3)–B(4)–S(1)

τ a3,1 [deg] a

H 3C

B

B

N

N

S B

H 3C

CH3

B S

CH3

N

CH3

CH3

126.4(4) 121.4(4) 110.3(5) b,c 98.4(3) 125.6(6) d 115.1(5) d

153.7(16) c -12.4(22) 37.9(10) -4.6(11) c 2.9(11) c 33.5(5) d 75.4(16) d

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties of the last digits are the estimated standard deviations deviations. Average value. c Restrained to the value from MP2_full/6-311++G** computation. d Dependent parameter. b

The GED experiment was carried out at Tnozzle of 428 and 453 K at the long and short nozzle-to-film distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆ra3,1 = ra − ra3,1, were calculated from the HF/6-31G* quadratic and cubic force fields by taking into account non-linear kinematic effects. By comparing the structures of the title molecule and its analogue with OH substituents it was shown that the N(CH3)2 groups twist the structure by approximately 30°.

9 Molecules with Seven to Nine Carbon Atoms

743

Wann DA, Robertson HE, Bramham G, Bull AEA, Norman NC, Russell CA, Rankin DWH (2009) Unusual chalcogen-boron ring compounds: The gas-phase structures of 1,4-B4S2(NMe2)4 and related molecules. Dalton Trans 8:1446-1449

2,3,4,5,6-Pentafluoro-α,α-bis(trifluoromethyl)benzenemethanol

846 CAS RN: 13732-52-0 MGD RN: 385103 GED augmented by QC computations

F

Bonds C–C (aromatic) C–C (aliphatic) C–O C–F

rh1[Å] a 1.400(2) b 1.549(5) b 1.409(5) 1.340(1) b

rg[Å] a 1.404(2) b 1.556(5) b 1.409(5) 1.339(1) b

Bond angles C(1)–C(7)–O C(1)–C(7)–C F–C–F

θh1 [deg] a

θg [deg] a

Dihedral angles C(6)–C–C–O C(1)–C–C–F(1) C(1)–C–C–F(2)

τh1 [deg] a

τg [deg] a

113.4(4) 110.2(4) b,c 107.2(2)

c

29.8(19) 85.8(8) c 66.7(22) c

C9HF11O C1 (syn) C1 (anti) OH

F

CF3 CF3

F

F F

113.2(4) 110.6(4)b,c 107.5(2)

31.0(15) c 86.2(9) c 65.4(23) c

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last digit were not identified, possibly estimated total errors. Average value. c Constrained to the value from MP2/TZVPP computation. b

The MP2/TZVPP computations predicted two lowest-energy conformers, syn and anti, differing in the locations of the hydrogen atom with respect to the C(1)–C(7) bond, i.e. with the synperiplanar and antiperiplanar H–O– C(1)–C(7) dihedral angles, respectively. The conformers are separated by a relative small energy difference of 1.7 kJ mol−1. The syn conformer is stabilized due to intramolecular hydrogen bond H…F(3) of 1.841 Å. These conformers could not be distinguished by GED because of low electron scattering by hydrogen atom. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-31G** computation. The rh1 structure was shown to be close to rg one. Trapp N, Scherer H, Hayes SA, Berger RJF, Kütt A, Mitzel NW, Saame J, Krossing I (2011) The perfluorinated alcohols (F5C6)(F3C)2COH and (F5C6)(F10C5)COH: Synthesis, theoretical and acidity studies, spectroscopy and structures in the solid state and the gas phase. Phys Chem Chem Phys 13 (13):6184-6191

847 CAS RN: 729-81-7 MGD RN: 420109 GED augmented by QC computations

1,3,5-Tris(trifluoromethyl)benzene α,α,α,αꞌ,αꞌ,αꞌ,αꞌꞌ,αꞌꞌ,αꞌꞌ-Nonafluoromesitylene C9H3F9 Cs

744

9 Molecules with Seven to Nine Carbon Atoms

Bonds C=C C–C C′–F′ C′–F C–H

rh1 [Å] a,b 1.392(4) 1.512(4) 1.348(2) 1 1.345(2) 1 1.079

Bond angles C(6)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C′ C(1)–C′–F′ C(1)–C′–F F′–C′–F

θh1 [deg] a,b

Dihedral angles C(2)–C(3)–C(4)–C(5) C(1)–C(2)–C(3)–C′ C(2)–C(3)–C′–F′ C(1)–C(2)–C(3)–C(4) C(5)–C(6)–C(1)–C′ C(6)–C(1)–C′–F′

τh1 [deg] a

120.9(2) 2 119.1(2) 2 119.6(2) 111.1(2) 3 111.9(2) 3 106.9(2)

-0.4 c 177.7 c -67.4(8) 0.2 c -177.4 c 88.7 c

Copyright 2014 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Structural parameters with equal superscripts were refined in one group; difference between parameters in each group was assumed at the value from MP2/cc-pVTZ computation. c Assumed at the value calculated at the level of theory as indicated above. b

According to predictions of MP2/cc-pVTZ calculations, the title compound exists as a mixture of two equimolar conformers with C3v and Cs symmetry, respectively. The barrier to rotation of the CF3 group was estimated to be very low (0.5 kJ mol-1). The GED experiment was carried out at Tnozzle = 298 K. The best fit to the experimental intensities was obtained for a molecular model of Cs symmetry using a static model, i.e. without accounting for the large amplitude motion effects of the almost freely rotating CF3 groups. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants computed at the level of theory indicated above. Kolesnikova IN, Dorofeeva OV, Karasev NM, Oberhammer H, Shishkov IF (2014) Molecular structure and conformation of 1,3,5-tris(trifluoromethyl)-benzene as studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 1074:196-200

848 CAS RN: 91-22-5 MGD RN: 193271 GED augmented by QC computations

Bonds

Quinoline C 9H 7N Cs

rh1 [Å] a

N

9 Molecules with Seven to Nine Carbon Atoms

C(2)=N(1) N(1)–C(8a) C(4)=C(3) C(6)–C(5) C(7)−C(8) C(3)–C(2) C(7)−C(6) C(4a)−C(4) C(8a)−C(8) C(5)−C(4a) C(8a)−C(4a)

1.32(1) 1.370(7) 1.375(8) 1.381(7) 1.387(8) 1.42(1) 1.414(8) 1.414(2) 1.415(2) 1.415(2) 1.420(8)

Bond angles C(8a)–N(1)=C(2) N(1)=C(2)–C(3) C(2)–C(3)=C(4) C(3)=C(4)–C(4a) C(4)−C(4a)–C(8a) C(4a)–C(8a)–N(1) C(4a)−C(5)–C(6) C(5)−C(6)–C(7) C(6)−C(7)–C(8) C(7)−C(8)–C(8a) C(8)−C(8a)–C(4a) C(8a)−C(4a)–C(5)

θh1 [deg] a

745

118(1) 124(1) 119(1) 119(1) 118(1) 122(1) 118(1) 122(1) 118(1) 122(1) 121(1) 119(1)

Table 5 reproduced with permission from de Gruyter, Berlin.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The GED experiment was carried out at Tnozzle=386(1) K. The title molecule was assumed to be planar. Restraints for the C–H bond lengths and for differences between some bond lengths and between the C–C–H bond angles were adopted from MP2/TZVPP computation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311G** computation. Berger RJF, Hoffmann M, Hayes SA, Mitzel NW (2009) An improved gas electron diffractometer - the instrument, data collection, reduction and structure refinement procedures. ZNaturforsch B 64 (11-12):12591268

849 CAS RN: 14371-10-9 MGD RN: 934410 MW supported by ab initio calculations Bonds C(1)–C(2) C(2)=C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(7) C(7)–C(8)

(2E)-3-Phenylpropenal trans-Cinnamaldehyde C9H8O Cs O

rs [Å] a 1.4745(18) 1.3568(26) 1.4270(7) 1.4254(11) 1.3980(5) 1.3824(24) 1.4081(18)

[Å] a r (1) m 1.456(34) 1.341(65) 1.464(62) 1.403(74) 1.410(25) 1.390(54) 1.399(41)

H

746

9 Molecules with Seven to Nine Carbon Atoms

C(8)–C(9) C(9)–C(4)

1.3935(4) 1.4003(13)

1.362(32) 1.414(89)

Bond angles C(1)–C(2)=C(3) C(2)=C(3)–C(4) C(3)–C(4)–C(9) C(4)–C(5)–C(6) C(5)–C(6)–C(7) C(6)–C(7)–C(8) C(7)–C(8)–C(9) C(8)–C(9)–C(4) C(9)–C(4)–C(5)

θs [deg] a

θ (1) [deg] a m

119.71(29) 126.55(16) 124.32(8) 121.14(7) 120.17(9) 119.81(4) 120.00(7) 121.54(4) 117.35(4)

121.3(59) 127.1(53) 124.5(54) 120.5(34) 120.1(5) 119.8(13) 119.5(23) 123.1(30) 116.9(35)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of trans-cinnamaldehyde were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8.5 GHz. Two conformers were observed, the s-trans-trans and the s-cis-trans form. structures were determined from the ground-state For the s-trans-trans conformer, the partial rs and r (1) m rotational constants of ten isotopic species (main and nine 13C). Zinn S, Betz T, Medcraft C, Schnell M (2015) Structure determination of trans-cinnamaldehyde by broadband microwave spectroscopy. Phys Chem Chem Phys 17(24):16080-16085

850 CAS RN: MGD RN: 572627 GED augmented by QC computations

N-(2,6-Dichlorophenyl)imidazolidin-2-imine Clonidine C9H9Cl2N3 C1 Cl

H N

Bonds N(1)–C(2) C(2)–N(3) N(3)–C(4) N(1)–C(5) C(4)–C(5) C(2)=N(6) N(6)–C(7) C(7)–C(8) C(8)–C(9) C(9)–C(10) C(10)–C(11) C(11)–C(12) C(12)–C(7) N–H C–H C(8)–Cl C(12)–Cl

rh1 [Å] a,b 1.390(2) 1 1.385(2) 1 1.468(7) 2 1.472(7) 2 1.549(7) 2 1.286(7) 1.388(2) 3 1.417(2) 3 1.396(2) 3 1.395(2) 3 1.397(2) 3 1.394(2) 3 1.418(2) 3 1.03(3) c 1.102(10) c 1.741(2) 4 1.733(2) 4

N

NH Cl

9 Molecules with Seven to Nine Carbon Atoms

Bond angles N(1)–C(2)–N(3) C(2)–N(3)–C(4) N(3)–C(2)=N(6) C(2)=N(6)–C(7) N(6)–C(7)–C(8) C(7)–C(8)–C(9) C(8)–C(9)–C(10) C(9)–C(10)–C(11) C(7)–C(8)–Cl C(7)–C(12)–Cl N(3)–C(4)–C(5) N(1)–C(5)–C(4) C(2)–N(1)–C(5) N(1)–C(2)=N(6) C(10)–C(11)–C(12) C(11)–C(12)–C(7) C(8)–C(7)–C(12)

θh1 [deg] a,b

Dihedral angles C(7)–C(8)–C(9)–C(10) C(8)–C(9)–C(10)–C(11) N(1)–C(2)–N(3)–C(4) C(4)–N(3)–C(2)=N(6) C(2)=N(6)–C(7)–C(8) N(6)–C(7)–C(8)–C(9) C(2)–N(3)–C(4)–C(5)

τh1 [deg] a

747

108.1(11) 5 110.7(11) 5 122.9(12) 6 122.5(12) 6 124.4(12) 6 123.0(2) 7 119.6(2) 7 119.8(2) 7 118.5(22) 8 118.0(22) 8 99.9(12) d 101.9(12) d 108.6(12) d 129.0(11) d 119.5(2) d 123.2(2) d 114.9(2) d

-0.1 e 0.0 e -11.8 e 166.6 e -72(6) -174.0 e 27.3(12) d

Reproduced with permission from the PCCP Owner Societies. a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/6-31G(d,p) computation. c Average value. d Dependent parameter. e Assumed at the value from computation at the level of theory as indicated above. b

The GED experiment was carried out at Tnozzle = 420 K. According to predictions of B3LYP and MP2 computations (with cc-pVTZ basis set), the title tautomer exists as a single conformer at this temperature. This tautomer was predicted to be lower in energy than the lowest energy conformer of the other tautomer (amino form) by 8.1 kcal mol-1 (MP2/cc-pVTZ). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were estimated using scaled quadratic force constants from B3LYP/6-31G(d,p) computations. Kolesnikova IN, Rykov AN, Shishkov IF, Tafeenko VA, Aslanov LA (2017) Molecular structure of clonidine: gas-phase electron diffraction, single-crystal X-ray diffraction and quantum chemical studies. Phys Chem Chem Phys 19 (6):4618-4626

851 CAS RN: 496-11-7 MGD RN: 127869 MW augmented by ab initio calculations

2,3-Dihydro-1H-indene Indan C9H10 Cs

748

9 Molecules with Seven to Nine Carbon Atoms

Bonds C(1)–C(2) C(1)–C(9) C(4)–C(5) C(4)–C(9) C(5)–C(6) C(6)–C(7)

rs [Å] a 1.547(7) 1.543(9) 1.359(9) 1.392(3) 1.402(5) 1.394(3)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(9) C(4)–C(5)–C(6) C(5)–C(6)–C(7) C(8)–C(9)–C(4)

θs [deg] a

Dihedral angle

τs [deg] a

θ

b

104.5(3) 103.2(8) 110.0(7) 118(1) 120.4(3) 121.5(8)

30(3)

Copyright 2015 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit. Puckering angle defined as an acute angle between the C(3)–C(4)–C(9)–C(1) and C(1)–C(2)–C(3) planes.

The rotational spectrum of the title compound was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 6 and 18.5 GHz. The rs structure of the heavy atom skeleton was determined from the ground-state rotational constants of six isotopic species (main and five 13C). The barrier to ring puckering of 733 cm-1 estimated at the MP2/6-311++G(d,p) level is quite higher than that of 488 cm-1determined previously by MW measurements. Favero LB, Li W, Spadini G, Caminati W (2015) Ring puckering splitting and structure of indan. J Mol Spectrosc 316(10):45-48

852 CAS RN: 1197-19-9 MGD RN: 131938 MW supported by ab initio calculations

4-(Dimethylamino)benzonitrile N,N-Dimethyl-p-cyanoaniline C9H10N2 Cs CH3 N a

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(1)–N(1) N(1)–C(7) C(4)–C(9) C(9)≡N(2)

rs [Å] 1.423 1.350 1.399 1.388 1.451 1.438 1.160

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4)

θs [deg] a 121.5 120.7

C

N CH3

9 Molecules with Seven to Nine Carbon Atoms

C(3)–C(4)–C(5) C(6)–C(1)–C(2) C(2)–C(1)–N(1) C(1)–N(1)–C(7)

749

118.9 116.5 121.7 119.9

Reprinted with permission. Copyright 2011 American Chemical Society. a

Uncertainties were not given in the original paper.

The rotational spectrum of 4-(dimethylamino)benzonitrile was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6 and 18 GHz. The substitution coordinates of the heavy-atom skeleton were determined from the ground-state rotational constants of nine isotopic species (main, six 13C and two 15N). The presented partial rs structure derived from these coordinates is not given in the original paper. Bird RG, Neill JL, Alstadt VJ, Young JW, Pate BH, Pratt DW (2011) Ground state 14N quadrupole couplings in the microwave spectra of N,N-dimethylaniline and 4,4-dimethylaminobenzonitrile. J Phys Chem A 115(34):9392-9398

853 CAS RN: 577-16-2 MGD RN: 371694 GED supported by QC computations

1-(2-Methylphenyl)ethanone 2-Methylacetophenone C9H10O C1 (synclinal) C1 (anticlinal) O

Bonds C(7)=O(8) C(1)–C(2) C(1)–C(6) C(5)–C(6) C(1)–C(7) C(2)–C(10) C(7)–C(9) C(4)–C(5) C–H

rh1 [Å] a,b,c 1.253(6) 1.413(4) 1 1.405(3) 1 1.395(3) 1 1.484(6) 2 1.495(6) 2 1.505(5) 2 1.392(5) d 1.115(4) e

Bond angles C(1)–C(7)=O(8) C(1)–C(7)–C(9) C(4)–C(5)–H C–C(methyl)–H C(1)–C(2)–C(3) C(1)–C(6)–C(5) C(2)–C(1)–C(6) C(2)–C(3)–C(4) C(1)–C(2)–C(10) C(2)–C(1)–C(7)

θh1 [deg] a,b,c

Dihedral and other angles tilt (CH3) C(2)–C(1)–C(7)=O(8) C(1)–C(7)–C(9)–H(1) C(1)–C(2)–C(10)–H(2)

122.0(8) 119.7(8) 120.0 f 110.0 f 117.8(4) 3 121.2(4) 3 119.5(3) 3 122.5(4) 3 122.1(7) 4 120.3(5) 4

synclinal 2.1 f,g 32.7(21) 47.2(48) 38.9(50)

CH3

CH3

synclinal

anticlinal

τh1 [deg] a

anticlinal 1.3 f,g 140.4(105) -28.4(53) -44.6(53)

750

9 Molecules with Seven to Nine Carbon Atoms

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Differences between parameters with equal superscripts were restrained to the values from MP2_full/6311++G** computation. c Many structural parameters of the anticlinal conformer were assumed to be equal to those of the synclinal conformer, except for some dihedral angles presented in the table. d Dependent parameter. e Average value. f Restrained to the value from computation as indicated above. g Positive values resulted in a smaller C(7)−C(9)−H(3) angle than the other two within the C(7)CH3 group. b

According to prediction of MP2_full/6-311++G** computations, the title molecule exists predominantly as a synclinal conformer (94%), characterized by a synclinal conformation of the C(2)−C(1)−C=O(8) unit. The existence of the second conformer, anticlinal, was predicted in abundance of less than 6%, an amount hardly detectable by GED. The GED experiment was carried out at the nozzle temperature of about 295 K. In the GED analysis, the benzene ring was assumed to have a symmetry plane bisecting the C(1)–C(2) and C(4)– C(5) bonds; the ratio of the conformers was adopted from computations. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from computation at the level of theory as indicated above. Hnyk D, Samdal S, Exner O, Wann DA, Rankin DWH (2010) Does 2-methylacetophenone comply with steric inhibition of resonance? A direct experimental proof of its nonplanar conformation from a joint ab initio/electron diffraction analysis. J Org Chem 75 (15):4939-4943

854 CAS RN: 43183-36-4 MGD RN: 363067 GED augmented by QC computations

1-(Trimethylsilyl)-1H-benzotriazole C9H13N3Si Cs (syn) Cs (anti) H 3C

Bonds Si–N Si–C C–H N(1)–C(7a) N(1)–N(2) N(2)=N(3) N(3)–C(3a) C(3a)–C(7a) C(3a)–C(4) C(7a)–C(7) C(6)–C(7) C(5)–C(6) C(4)–C(5) Bond angles N–Si–C Si–C–H Si–N(1)–N(2)

rh1 [Å] a,b syn anti 1.806(8) c 1.806(8) c 1.861(3) 1.861(3) 1.095(4) 1.095(4) 1.363(4) 1.363(4) 1.387(5) 1.387(5) 1.313(5) 1.313(5) 1.363(4) 1.363(4) 1.420(4) 1.420(4) 1.409(1) 1.409(1) 1.409(1) 1.409(1) 1.387(4) 1.387(4) 1.425(4) 1.425(4) 1.383(4) 1.383(4)

syn 106.8(3) 111.9(5) 117.4(6)

θh1 [deg] a,b

anti 106.8(3) 111.9(5) 112.6(6)

CH3 Si

CH3

N N N

syn

9 Molecules with Seven to Nine Carbon Atoms

Si–N(1)–C(7a) N(1)–N(2)=N(3) N(2)–N(1)–C(7a) N(2)=N(3)–C(3a) N(3)–C(3a)–C(7a) N(1)–C(7a)–C(3a) C(3a)–C(7a)–C(7) C(7a)–C(7)–C(6) C(5)–C(6)–C(7) C(6)–C(5)–C(4) C(3a)–C(4)–C(5) C(7a)–C(3a)–C(4) C(7a)–C(7)–H C(7)–C(6)–H C(6)–C(5)–H C(5)–C(4)–H

134.2(10) 109.8(4) 109.2(3) 107.3(3) d 110.0(2) 103.7(2) 121.6(5) 117.9(5) c 121.0(6) 121.1(8) 118.9(9) 119.6(8) 123.6(11) 120.1(13) 119.1(7) 121.0(11)

751

138.2(10) 109.8(4) 109.2(3) 107.3(3) d 110.0(2) 103.7(2) 121.6(5) 117.9(5) c 121.0(6) 121.1(8) 118.9(9) 119.6(8) 123.6(11) 120.1(13) 119.1(7) 121.0(11)

anti

Reproduced with permission from The Royal Society of Chemistry.

a Parenthesized uncertainties in units of the last significant digit were not identified, they are presumably the estimated standard deviations. b Structural parameters of the syn and anti conformers were assumed to be identical, except for the Si–N(1)–N(2) and Si–N(1)–C(7a) bond angles. c Restrained to the value from MP2/6-311++G** computation. d Dependent parameter.

Ab initio (HF/3-21G*) computations predicted existence of the syn and anti conformers, characterized by the synperiplanar and antiperiplanar N–N–Si–C torsional angles, respectively, with the syn conformer being lower in energy. The free energy difference was estimated to be of 0.16 kJ mol–1, i.e. much smaller than the thermal energy RT. Therefore, the rotation of the Si(CH3)3 group about the N–Si bond was described in the GED analysis by a dynamic model, including both conformers and six pseudo-conformers. The silyl group and each of the methyl groups were assumed to have local C3v symmetry. Benzotriazole moieties were assumed to be identical in all eight conformations. The GED experiment was carried out at Tnozzle of 439 and 478 K at the short and long nozzle-to-film distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using ab initio harmonic force field. Foerster T, Wann DA, Robertson HE, Rankin DWH (2009) Why are trimethylsilyl groups asymmetrically coordinated? Gas-phase molecular structures of 1-trimetylsilyl-1,2,3-benzotriazole and 2-trimethylsilyl-1,3thiazole. Dalton Trans 16:3026-3033

855 CAS RN: 24903-95-5 MGD RN: 443400 MW supported by QC calculations

6,6-Dimethylbicyclo[3.3.1]heptan-2-one Nopinone C9H14O C1 H 3C

H 3C

Bonds C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(2)

r0 [Å] a 1.535(7) 1.546(6) 1.542(7) 1.553(9) 1.501(11)

r (1) [Å] a m 1.525(10) 1.544(8) 1.533(13) 1.545(11) 1.499(13)

O

752

9 Molecules with Seven to Nine Carbon Atoms

C(5)–C(7) C(6)–C(8) C(6)–C(9) C(2)=O C(1)–C(7) C(1)–C(6)

1.551(10) 1.528(12) 1.535(7) 1.214(4) 1.561(6) 1.579(11)

1.559(13) 1.539(18) 1.526(10) 1.215(5) 1.554(8) 1.564(18)

Bond angles C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(1)–C(2)–C(3) C(4)–C(5)–C(7) C(1)–C(6)–C(8) C(5)–C(6)–C(9) C(6)–C(5)–C(7) C(5)–C(6)–C(1) C(6)–C(1)–C(7) C(6)–C(1)–C(2) O=C(2)–C(3) O=C(2)–C(1) C(2)–C(1)–C(7) C(8)–C(6)–C(5) C(9)–C(6)–C(1) C(5)–C(7)–C(1) C(8)–C(6)–C(9)

θ0 [deg] a

θ (1) [deg] a m

Dihedral angles C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6) C(1)–C(2)–C(3)–C(4) C(3)–C(4)–C(5)–C(7) C(8)–C(6)–C(1)–C(2) C(4)–C(5)–C(6)–C(9) O=C(2)–C(1)–C(7) O=C(2)–C(1)–C(6) O=C(2)–C(3)–C(4) C(8)–C(6)–C(5)–C(4) C(8)–C(6)–C(5)–C(7) C(9)–C(6)–C(5)–C(7) C(4)–C(5)–C(7)–C(1) C(4)–C(5)–C(6)–C(1) O=C(2)–C(3)–C(1)

τ0 [deg] a

τ (1) [deg] a m

114.1(2) 111.3(3) 111.1(5) 114.9(4) 108.7(5) 117.6(5) 112.1(6) 88.3(5) 85.9(6) 87.1(5) 107.7(6) 121.4(6) 123.6(6) 108.7(5) 119.9(8) 111.0(8) 86.7(6) 108.7(6)

-16.1(9) 55.5(8) 18.8(11) -40.1(5) -38.7(8) 165.3(8) -145.7(11) 121.3(9) -160.7(9) 36.0(7) 145.4(5) -85.3(8) 85.7(5) -83.8(7) -179.5(14)

114.1(2) 111.5(4) 111.9(10) 115.0(4) 108.4(6) 117.5(6) 112.7(9) 87.5(9) 86.6(8) 86.9(7) 108.2(3) 121.3(6) 123.7(7) 108.8(8) 118.8(12) 112.1(13) 86.5(4) 108.0(8)

-15.8(10) 54.4(15) 18.9(12) -40.4(6) -38.4(10) 164.9(10) -145.8(12) 121.2(10) -160.5(9) 37.1(11) 145.9(7) -86.2(12) 85.8(7) -82.3(11) -179.6(16)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of nopinone were investigated in a supersonic jet by an FTMW spectrometer in the frequency region between 2 and 20 GHz.

9 Molecules with Seven to Nine Carbon Atoms

753

The partial r0 and r (1) structures were determined from the ground-state rotational constants of eleven isotopic m species (main, nine 13C and 18O). Neeman EM, Avilés-Moreno JR, Huet TR (2017) The quasi-unchanged gas-phase molecular structures of the atmospheric aerosol precursor β-pinene and its oxidation product nopinone. Phys Chem Chem Phys 19(4):13819-13827

856 CAS RN: 552-70-5 MGD RN: 375539 MW augmented by ab initio calculations

9-Methyl-9-azabicyclo[3.3.1]nonan-3-one Pseudopelletierine C9H15NO Cs H3C

a

a

a

Bonds C(1)–C(2) C(2)–C(3) C(1)–C(8) C(6)–C(7) C(1)–N C(10)–N C(3)=O(11) C(1)–H C(2)–H(1) C(2)–H(2) C(6)–H(3) C(6)–H(4) C(7)–H(5) C(7)–H(6) C(10)–H(7) C(10)–H(8)

r0 [Å] 1.549(14) 1.517(17) 1.533(9) 1.532(22) 1.467(18) 1.457(7) 1.222(6)

rs [Å] 1.557(17) 1.518(19) 1.48(3) 1.58(2) 1.48(2) 1.462(6) 1.199(3)

r [Å] 1.5435(10) 1.5115(10) 1.5277(10) 1.52613(99) 1.46076(95) 1.4520(10) 1.2136(10) 1.0919(13) 1.0943(13) 1.0892(13) 1.0916(13) 1.0916(13) 1.0906(13) 1.0918(20) 1.0897(13) 1.0989(13)

Angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(6)–C(7)–C(8) C(1)–C(8)–C(7) N–C(1)–C(2) N–C(1)–C(8) C(1)–N–C(10) C(2)–C(3)=O(11) C(1)–N–C(5) N–C(1)–H C(1)–C(2)–H(1) C(1)–C(2)–H(2) C(5)–C(6)–H(3) C(6)–C(7)–H(5) C(6)–C(7)–H(6) N–C(10)–H(7) H(8)–C(10)–N

θ0 [deg] a

θs [deg] a

θ see [deg] a

113.6(14) 122.2(13) 110.5(9)

115.1(48) 122.3(16) 109.0(14)

Dihedral angles N–C(1)–C(2)–C(3) N–C(5)–C(6)–C(7)

113.1(12) 116.3(9) 109.7(17) 112.1(12)

112.8(9) 115.0(3) 104.9(18) 111.0(6)

τs [deg] a 52.0(16)

se e

113.078(80) 115.069(76) 110.700(87) 111.839(73) 112.351(78) 108.582(83) 113.342(58) 122.451(38) 110.699(75) 107.10(20) 108.79(20) 111.88(15) 107.68(22) 109.787(22) 110.24(10) 109.04(19) 114.77(20)

τ see [deg] a 49.64(10) 56.788(92)

N O

754

9 Molecules with Seven to Nine Carbon Atoms

C(10)–N–C(5)–C(6) C(10)–N–C(1)–C(2) C(1)–C(2)–C(3)=O(11) C(10)–N–C(5)–H N–C(1)–C(2)–H(1) C(8)–C(1)–C(2)–H(2) N–C(5)–C(6)–H(3) C(4)–C(5)–C(6)–H(4) C(5)–C(6)–C(7)–H(5) C(5)–C(6)–C(7)–H(6) H(7)–C(10)–N–C(1) H(8)–C(10)–N–C(5)

-165.22(22) 146.1(11)

-166.268(95) 68.917(98) 141.94(18) 49.49(16) -68.44(22) 50.17(22) -63.41(22) 54.78(22) -171.95(23) 71.65(14) 175.33(21) 63.632(59)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of pseudopelletierine was recorded by a pulsed-jet Balle-Flygare-type FTMW spectrometer in the frequency range between 6 and 18 GHz. Two conformers originating due to the inversion of the N-methyl group from an axial to an equatorial position were unambiguously detected. The relative population of the conformers was determined to be axial : equatorial ≈ 2 : 1. The partial r0 and rs structures of the most abundant conformer were determined from the experimental groundstate rotational constants of seven isotopic species (main, four 13C, 15N and 18O). The semiexperimental equilibrium structure r see was obtained by taking into account rovibrational corrections, ΔBe = Be ‒ B0, calculated with the MP2/cc-pVTZ harmonic and anharmonic (cubic) force fields. For the predicate regression, the molecular structure was optimized at different levels of theory up to CCSD(T)/cc-pVTZ with correction for core-core and core-valence correlation effects as well as with extrapolation to QZ basis set. The close convergence of the computed and semiexperimental equilibrium structures demonstrated success of ab initio and spectroscopy to provide accurate structures for increasingly larger molecules. Vallejo-López M, Écija P, Vogt N, Demaison J, Lesarri A, Basterretxea FJ, Cocinero EJ (2017) N-Methyl inversion and accurate equilibrium structures in alkaloids: Pseudopelletierine. Chem Eur J 23(65):16491-16496

857 CAS RN: 52755-58-5 MGD RN: 464801 GED augmented by QC computations

Bonds Si–C(7) Si–C(2) C(2)–C(3) C(3)–C(4)

1-(1,1-Dimethylethyl)silacyclohexane 1-tert-Butylsilacyclohexane C9H20Si Cs (equatorial) CH3

rh1 [Å] a 1.909(25) 1.884(13) 1.542(4) 1.535(4)

SiH

CH3 CH3

9 Molecules with Seven to Nine Carbon Atoms

C–H Si–H C(7)–C

1.103(2) b 1.491 c 1.535(4) b

Bond angles C(2)–Si–C(6) C(3)–C(4)–C(5) H–C–H C(2)–C(3)–C(4) Si–C(2)–C(3) C(7)–Si–C(2) Cʹʹ–C(7)–Si Cʹ–C(7)–Si H(s)–Cʹʹ–C(7) H(a)–Cʹʹ–C(7)

θh1 [deg] a

Dihedral angles C(2)–Si–C(6)–C(5) Si–C(6)–C(5)–C(4) C(6)–C(5)–C(4)–C(3)

τh1 [deg] a

755

104.1(28) 114.6(21) 106.5 b,c 114.7(22) 111.8(10) 114.1(10) 110.3(15) 108.7(15) 109.8(28) 111.6(28)

-43.0(57) 53.6(22) -62.3(23)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digits are 3σ values. Average value. c Assumed at the value from DFT computation at the level of theory as indicated below. b

The GED experiment was carried out at Teffusion cell = 283(10) K. Two conformers, characterized by the equatorial and axial positions of the tert-butyl group with respect to the ring, were predicted by QC computations. The equatorial conformer was predicted to be lower in energy (∆G = Gax − Geq = 1.19 kcal mol−1 (CCSD(T)/CBS)). The best fit to the experimental intensities was obtained for 100(4) % contribution of the equatorial conformer. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from M06-2X/aug-cc-pVTZ computation. According to results of NBO analysis, stabilization of the equatorial conformer is favoured by electrostatic interactions and not by steric and conjugation effects. Belyakov AV, Sigolaev Y, Shlykov SA, Wallevik SÓ, Jonsdottir NR, Bjornsson R, Jonsdottir S, Kvaran Á, Kern T, Hassler K, Arnason I (2015) Conformational properties of 1-tert-butyl-1-silacyclohexane, C5H10SiH(t-Bu): gas-phase electron diffraction, temperature-dependent Raman spectroscopy, and quantum chemical calculations. Struct Chem 26 (2):445-453

858 CAS RN: 101028-79-9 MGD RN: 464604 GED augmented by QC computations

Bonds C(1)–Si(2) Si(2)–C(12) Si–Br C–H

Methanetetrayltetrakis(bromodimethylsilane) 2,4-Dibromo-3,3-bis(bromodimethylsilyl)-2,4-disilapentane C9H24Br4Si4 C1 (I) C2 (II)

rh1 [Å] a,b 1.911(5) 1.862(3) 2.266(2) 1.093(5)

756

Bond angles Si(2)–C(1)–Si(3) C(1)–Si(2)–C(12) C(1)–Si(2)–C(13) C(1)–Si(2)–Br(14) C(10)–Si(4)–C(11) C(10)–Si(4)–Br(15) Si–C–H Dihedral angles Br(14)–Si(2)–C(1)–Si(3) Br(16)–Si(3)–C(1)–Si(2) Br(15)–Si(4)–C(1)–Si(2) Br(17)–Si(5)–C(1)–Si(2) H(1)–C(12)–Si(2)–Br(14) H(2)–C(13)–Si(2)–Br(14) Br(14)–Si(2)–C(1)–Si(4)

9 Molecules with Seven to Nine Carbon Atoms

θh1 [deg] a,b 108.4(2) 118.3(5) 116.4(5) 107.6(3) 109.0(10) 102.2(3) 110.5(4)

τh1 [deg] a,b

I 39.6(8) 158.7(6) -72.7(11) 35.0(14) -177.2(12) 177.8(33)

I

II

166.4(8)

-80.6(11)

Table 5 reproduced with permission from de Gruyter, Berlin.

II

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Some structural parameters and/or their differences were restrained to the values from MP2/aug-cc-pVDZ(PP) computations.

b

The GED experiment was carried out at Tnozzle of 223 and 233 K at the long and short nozzle-to-film distances, respectively. According to predictions of M06-2X/6-31G(d) computations, mainly two conformers, I and II, differing in the magnitude of the Br–Si–C–Si torsional angle, occur in the gas phase at the temperature of the experiment in amounts of 75.5 (I) and 16.7 (II) %, respectively. In the GED analysis, the ratio of the conformers was refined to be I : II = 73(16) : 27(16). Local C3v symmetry was assumed for each of the methyl groups. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X/6-31G(d) computation. The bond lengths and angles are presented for the main conformer. Wann DA, Young S, Bätz K, Masters SL, Avent AG, Rankin DWH, Lickiss PD (2014) Structures of tetrasilylmethane derivatives C(SiXMe2)4 (X = H, F, Cl, Br) in the gas phase and their dynamic structures in solution. Z Naturforsch, B 69 (11-12):1321-1332

859 CAS RN: 17082-83-6 MGD RN: 464432 GED augmented by QC computations

Bonds C(1)–Si(2) Si(2)–C(12)

Methanetetrayltetrakis(chlorodimethylsilane) 2,4-Dichloro-3,3-bis(chlorodimethylsilyl)-2,4-disilapentane C9H24Cl4Si4 C1 (I) C2 (II)

rh1 [Å] a,b 1.920(4) 1.891(4)

9 Molecules with Seven to Nine Carbon Atoms

Si(2)–Cl(14) C–H

2.091(2) 1.108(6)

Bond angles Si–C–Si C(1)–Si(2)–C(12) C(1)–Si(2)–C(13) C(1)–Si(2)–Cl(14) C(10)–Si(4)–C(11) C(10)–Si(4)–Cl(15) Si–C–H

θh1 [deg] a,b

Dihedral angles Cl(14)–Si(2)–C(1)–Si(3) Cl(16)–Si(3)–C(1)–Si(2) Cl(15)–Si(4)–C(1)–Si(2) Cl(17)–Si(5)–C(1)–Si(2) H(1)–C(12)–Si(2)–Cl(14) H(2)–C(13)–Si(2)–Cl(14) Cl(14)–Si(2)–C(1)–Si(4)

757

110.2(4) 115.3(4) 113.8(4) 107.4(5) 107.0(20) 107.0(8) 110.5(5)

I

τh1 [deg] a,b

Ι 39.9(4) 159.1(5) -74.9(11) 34.7(5) -176.7(24) 176.3(30)

ΙΙ

165.2(7)

-75.3(6)

II

Table 4 reproduced with permission from de Gruyter, Berlin.

a

Parenthesized uncertainties in units of the last digit are 1σ values. Some structural parameters and/or their differences were restrained to the values from MP2/aug-cc-pVDZ computations.

b

The GED experiment was carried out at Tnozzle of 203 and 217 K at the long and short nozzle-to-film distances, respectively. According to predictions of M06-2X/6-31G(d) computations, mainly two conformers, I and II, differing in the magnitude of the Cl–Si–C–Si torsional angle, occur in the gas phase at the temperature of the experiment in amounts of 51.1 (I) and 37.4 %, respectively. In the GED analysis, the ratio of the conformers was assumed to be I : II = 72 : 28. Local C3v symmetry was assumed for each of the methyl groups. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X/6-31G(d) computation. The bond lengths and angles are presented for the main conformer. Wann DA, Young S, Bätz K, Masters SL, Avent AG, Rankin DWH, Lickiss PD (2014) Structures of tetrasilylmethane derivatives C(SiXMe2)4 (X = H, F, Cl, Br) in the gas phase and their dynamic structures in solution. Z Naturforsch, B 69 (11-12): 1321-1332

860 CAS RN: 103588-64-3 MGD RN: 464259 GED augmented by QC computations

Bonds C(1)–Si(2) Si(2)–C(12)

Methanetetrayltetrakis(fluorodimethylsilane) 2,4-Difluoro-3,3-bis(fluorodimethylsilyl)-2,4-disilapentane C9H24F4Si4 C1 (I), C1 (II), C2 (III), C2 (IV), C2 (V), C2 (VI), C1 (VII)

rh1 [Å] a,b 1.893(2) 1.865(2)

758

9 Molecules with Seven to Nine Carbon Atoms

Si–F C–H

1.606(1) 1.093(3)

Bond angles Si–C–H C–Si–C(m) c C(m)–Si–C(m) c C–Si–F C(m)–Si–F c Si–C–Si

θh1 [deg] a,b

Dihedral angles conformer I F(14)–Si(2)–C(1)–Si(3) F(16)–Si(3)–C(1)–Si(2) F(15)–Si(4)–C(1)–Si(2) F(17)–Si(5)–C(1)–Si(2) conformer II F(14)–Si(2)–C(1)–Si(3) F(16)–Si(3)–C(1)–Si(2) F(15)–Si(4)–C(1)–Si(2) F(17)–Si(5)–C(1)–Si(2) conformer III F(14)–Si(2)–C(1)–Si(3) F(16)–Si(3)–C(1)–Si(2) F(15)–Si(4)–C(1)–Si(2) F(17)–Si(5)–C(1)–Si(2) conformer IV F(14)–Si(2)–C(1)–Si(3) F(16)–Si(3)–C(1)–Si(2)

τh1 [deg] a,b

109.7(4) 115.9(11) 113.1(13) 104.9(6) 106.0(6) 110.2(3)

81.9(39) -167.2(10) -153.2(20) -39.2(29) 84.7(26) -40.9(33) -166.0(46) 71.2(46) 77.5(62) -163.9(46) -42.2 d -44.2 d 84.9(26) -41.9(17)

I

Table 3 reproduced with permission from de Gruyter, Berlin.

II

III

IV

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Some structural parameters and/or their differences were restrained to the values from MP2/aug-cc-pVDZ computations. c Carbon atom of the methyl group is labelled by C(m). d Dihedral angle is derived from the Cartesian coordinates given in supplemental material to this paper. b

The GED experiment was carried out at Tnozzle of 141 and 173 K at the long and short nozzle-to-film distances, respectively.

9 Molecules with Seven to Nine Carbon Atoms

759

According to predictions of M06-2X/6-31G(d) computations, seven conformers, differing in the magnitude of the F–Si–C–Si torsional angle, occur in the gas phase at this temperature in remarkable amounts: 32.0% (I), 26.2% (II), 11.1% (III), 10.4% (IV), 7.5% (V), 6.2% (VI) and 5.1% (VII) %. The predicted ratio of the conformers was assumed in the GED analysis. Local C3v symmetry was assumed for each of the methyl groups. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X/6-31G(d) computation. The bond lengths and angles are presented for the main conformer (I). Wann DA, Young S, Bätz K, Masters SL, Avent AG, Rankin DWH, Lickiss PD (2014) Structures of tetrasilylmethane derivatives C(SiXMe2)4 (X = H, F, Cl, Br) in the gas phase and their dynamic structures in solution. Z Naturforsch, B 69 (11-12):1321-1332

861 CAS RN:14595-80-3 MGD RN: 464051 GED augmented by QC computations

Methanetetrayltetrakis(dimethylsilane) 3,3-Bis(dimethylsilyl)-2,4-dimethyl-2,4-disilapentane C9H28Si4 C2 (I), C2 (II), C1 (III), C1 (IV), D2 (V), C1 (VI), C1 (VII), C2 (VIII), C2 (IX)

Bonds C(1)–Si(2) Si(2)–C(12) Si–H C–H

rh1 [Å] a,b 1.894(4) 1.892(2) 1.498(8) 1.096(2)

Bond angles Si–C–H C–Si–C(m) c C(m)–Si–C(m) c C–Si–H C(m)–Si–H c Si–C–Si

θh1 [deg] a,b

Dihedral angles conformer I H(1)–Si(2)–C(1)–Si(4) H(2)–Si(4)–C(1)–Si(2) H(5)–C(12)–Si(2)–H(1) H(6)–C(13)–Si(2)–H(1) conformer II H(1)–Si(2)–C(1)–Si(3) H(3)–Si(3)–C(1)–Si(2) H(2)–Si(4)–C(1)–Si(2) H(4)–Si(5)–C(1)–Si(2) conformer III H(1)–Si(2)–C(1)–Si(3) H(3)–Si(3)–C(1)–Si(2) H(2)–Si(4)–C(1)–Si(2) H(4)–Si(5)–C(1)–Si(2) conformer IV H(1)–Si(2)–C(1)–Si(3) H(3)–Si(3)–C(1)–Si(2) H(2)–Si(4)–C(1)–Si(2) H(4)–Si(5)–C(1)–Si(2) conformer V H(1)–Si(2)–C(1)–Si(4)

τh1 [deg] a,b

110.9(3) 114.2(4) 106.7(6) 107.6(4) 106.7(8) 111.8(2)

-74.9(21) 161.6(5) 186.6(45) 177.4(35) 46.6(44) 46.4(44) 39.4(10) -79.8(11) 39.6(61) 45.2(15) 159.9(12) -75.9(8) 46.8(6) 41.9(12) 40.9(28) 161.6(14) 41.0 d

760

9 Molecules with Seven to Nine Carbon Atoms

conformer VI H(1)–Si(2)–C(1)–Si(3) H(3)–Si(3)–C(1)–Si(2) H(2)–Si(4)–C(1)–Si(2) H(4)–Si(5)–C(1)–Si(2) conformer VII H(1)–Si(2)–C(1)–Si(3) H(3)–Si(3)–C(1)–Si(2) H(2)–Si(4)–C(1)–Si(2) H(4)–Si(5)–C(1)–Si(2) conformer VIII H(1)–Si(2)–C(1)–Si(3) H(3)–Si(3)–C(1)–Si(2) conformer IX H(1)–Si(2)–C(1)–Si(4) H(2)–Si(4)–C(1)–Si(2)

41.0(60) 161.9(27) 41.6(20) -81.5(23) 42.7(14) 160.6(18) -77.1(7) 37.2(21) 37.1(18) 164.9(18) -76.9(9) 39.7(13)

Table 2 reproduced with permission from de Gruyter, Berlin.

I

II

III

IV

VII

V

VIII

VI

IX

9 Molecules with Seven to Nine Carbon Atoms

761

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Some structural parameters and/or their differences were restrained to the values from MP2/aug-cc-pVDZ computations. c Carbon atom of the methyl group is labelled by C(m). d Dihedral angle is derived from the Cartesian coordinates given in supplemental material to this paper. b

The GED experiment was carried out at the nozzle temperatures of 115 and 133 K at the long and short nozzleto-film distances, respectively. According to predictions of M06-2X/6-31G(d) computations, nine conformers, differing in the magnitude of the H–Si–C–Si dihedral angle, occur in gas phase at this temperature in the ratio I : II : III : IV : V : VI : VII : VIII :IX : X = 25.6 : 16.7 : 12.8 : 11.8 : 10.1 : 8.0 : 5.2 : 5.1 : 4.6 (in %). In the GED analysis, the ratio of the conformers was adopted from the computations. Local C3v symmetry of each of the methyl groups was assumed. Vibrational corrections to the experimental internuclear distances, ∆rh1= ra − rh1, were calculated using quadratic force constants from M06-2X/6-31G(d) computation. The bond lengths and angles are presented for the main conformer (I). Wann DA, Young S, Bätz K, Masters SL, Avent AG, Rankin DWH, Lickiss PD (2014) Structures of tetrasilylmethane derivatives C(SiXMe2)4 (X = H, F, Cl, Br) in the gas phase and their dynamic structures in solution. Z Naturforsch, B 69 (11-12):1321-1332

762

9 Molecules with Seven to Nine Carbon Atoms

References: 768 769 770 771 772

773 774 775 776 777 778 779

780 781 782 783 784 785 786 787 788 789 790

791 792

Kamaee M, Sun M, Luong H, van Wijngaarden J (2015) Investigation of structural trends in mono-, di-, and pentafluorobenzonitriles using Fourier transform microwave spectroscopy. J Phys Chem A 119(41):10279-10292 Kafka GR, Masters SL, Wann DA, Robertson HE, Rankin DWH (2010) Low symmetry in molecules with heavy peripheral atoms. The gas-phase structure of perfluoro(methylcyclohexane), C6F11CF3. J Phys Chem A 114 (41):11022-11026 See 768. See 768. Johansen TH, Dahl PI, Hagen K (2013) Molecular conformational structures of 2fluorobenzoyl chloride, 2-chlorobenzoyl chloride, and 2-bromobenzoyl chloride by gas electron diffraction and normal coordinate analysis aided by quantum chemical calculations. Struct Chem 24 (3):789-805 See 722. See 722. See 768. See 768. Favero L, Caminati W, Grabow JU (2009) The m=0 state of the low-barrier torsion in α,α,αtrifluorobenzene (benzotrifluoride). J Mol Spectrosc 255(2):199-201 Kang L, Novick SE, Gou Q, Spada L, Vallejo-López M, Caminati W (2014) The shape of trifluoromethoxybenzene. J Mol Spectrosc 297:32-34 (a) Rudolph HD, Demaison J, Császár AG (2013) Accurate determination of the deformation of the benzene ring upon substitution: equilibrium structures of benzonitrile and phenylacetylene. J Phys Chem A 117(48):12969-12982 (b) See 768. Nair KPR, Jahn MK, Lesarri A, Ilyushin VV, Grabow JU (2015) Six-fold-symmetry internal rotation in toluenes: the low barrier challenge of 2,6- and 3,5-difluorotoluene. Phys Chem Chem Phys 17(39):26463-26470 See 780. Nair KPR, Wachsmuth D, Grabow JU, Lesarri A (2017) Internal rotation in halogenated toluenes: Rotational spectrum of 2,5-difluorotoluene. J Mol Spectrosc 337(1):46-50 Dehghany M, Norooz Oliaee J, Afshari M, Moazzen-Ahmadi N, McKellar ARW (2010) Infrared spectra of OCS-C6H6, OCS-C6H6-He, and OCS-C6H6-Ne van der Waals complexes. J Chem Phys 132(19):194303/1-194303/6 See 783. See 783. Dorosh O, Białkowska-Jaworska E, Kisiel Z, Pszczółkowski L, Kańska M, Krygowski TM, Mäder H (2017) The complete molecular geometry and electric dipole moment of salicylaldehyde from rotational spectroscopy. J Mol Spectrosc 335(5):3-12 Evangelisti L, Tang S, Velino B, Caminati W (2009) Microwave spectrum of salicylic acid. J Mol Struct 921(1-3):285-288 Gou Q, Feng G, Evangelisti L, Loru D, Alonso JL, López JC, Caminati W (2013) Ubbelohde effect within weak C-H⋅⋅⋅π hydrogen bonds: the rotational spectrum of benzene-DCF3. J Phys Chem A 117(50):13531-13534 Gou Q, Spada L, Vallejo-López M, Kang L, Novick SE, Caminati W (2014) Fluorination effects on the shapes of complexes of water with ethers: a rotational study of trifluoroanisolewater. J Phys Chem A 118(6):1047-1051 Mackenzie RB, Dewberry CT, Coulston E, Cole GC, Legon AC, Tew DP, Leopold KR (2015) Intramolecular competition between n-pair and π-pair hydrogen bonding: Microwave spectrum and internal dynamics of the pyridine-acetylene hydrogen-bonded complex. J Chem Phys 143(10):104309/1-104309/10 Marochkin II, Dorofeeva OV (2013) Molecular structure and relative stability of trans and cis isomers of formanilide: Gas-phase electron diffraction and quantum chemical studies. Struct Chem 24 (1):233-242 (a) Kuze N, Sakaizumi T, Ohashi O, Yokouchi Y, Iijima K (2010) Molecular structure of (E)benzaldehyde oxime from gas-phase electron diffraction, quantum-chemical calculations and microwave spectroscopy. J Mol Struct 978 (1-3):195-200

9 References

793 794

795 796

797 798 799 800 801 802

803 804

805 806 807

808 809

763

(b) Kuze N, Sato M, Maue K, Usami T, Sakaizumi T, Ohashi O, Iijima K (1999) Microwave spectrum and molecular conformation of (E)-benzaldehyde oxime. J. Mol. Spectrosc 196:283289 Kolesnikova IN, Hargittai I, Shishkov IF (2015) Equilibrium molecular structure of benzamide from gas-phase electron diffraction and theoretical calculations. Struct Chem 26 (56):1473-1479 Aarset K, Page EM, Rice DA (2013) Hydrogen bonding in the gas-phase: The molecular structures of 2-hydroxybenzamide (C7H7NO2) and 2-methoxybenzamide (C8H9NO2), obtained by gas-phase electron diffraction and theoretical calculations. J Phys Chem A 117 (14):30343040 Graneek JB, Pérez C, Schnell M (2017) Structural determination and population transfer of 4nitroanisole by broadband microwave spectroscopy and tailored microwave pulses. J Chem Phys 147(15):154306/1-154306/10 Celebre G, DeLuca G, DiPietro ME, Giuliano BM, Melandri S, Cinacchi G (2015) Detection of significant aprotic solvent effects on the conformational distribution of methyl 4-nitrophenyl sulfoxide: from gas-phase rotational to liquid-crystal NMR spectroscopy. ChemPhysChem 16(11):2327-2337 Giricheva NI, Fedorov MS, Ivanov SN, Girichev GV (2015) The difference between gas-phase and crystal structures of ortho-nitromethylbenzenesulfonate. Conformation variety study of free molecules by electron diffraction and quantum chemistry. J Mol Struct 1085:191-197 Giricheva NI, Fedorov MS, Girichev GV (2015) Conformations of methylbenzenesulfonate and its substituted derivatives: gas-phase electron diffraction versus vibrational spectroscopy. Struct Chem 26 (5-6):1543-1553 Calabrese C, Maris A, Evangelisti L, Caminati W, Melandri S (2013) Fluorine substitution effects on flexibility and tunneling pathways: the rotational spectrum of 2-fluorobenzylamine. ChemPhysChem 14(9):1943-1950 Dorofeeva OV, Shishkov IF, Karasev NM, Vilkov LV, Oberhammer H (2009) Molecular structures of 2-methoxyphenol and 1,2-dimethoxybenzene as studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 933 (1-3):132-141 Schnitzler EG, Jäger W (2014) The benzoic acid-water complex: a potential atmospheric nucleation precursor studied using microwave spectroscopy and ab initio calculations. Phys Chem Chem Phys 16(6):2305-2314 Giricheva NI, Girichev GV, Fedorov MS, Ivanov SN (2013) Substituent effect on geometric and electronic structure of benzenesulfonic acid: Gas-phase electron diffraction and quantum chemical studies of 4-CH3C6H4SO3H and 3-NO2C6H4SO3H molecules. Struct Chem 24 (3):807-818 Noble-Eddy R, Masters SL, Rankin DWH, Wann DA, Robertson HE, Khater B, Guillemin J-C (2009) Primary phosphines studied by gas-phase electron diffraction and quantum chemical calculations. Are they different from amines? Inorg Chem 48 (17):8603-8612 Durig JR, Klaassen JJ, Deodhar BS, Darkhalil ID, Herrebout WA, Dom JJJ, van der Veken BJ, Purohita SS, Guirgis GA (2013) Conformational and structural studies of ethynylcyclopentane from temperature dependent Raman spectra of xenon solutions, infrared spectra, and ab initio calculations. J Mol Struct 1044:10-20 Shlykov SA, Phien TD, Trang NH (2017) Orbital interaction between electron lone pair and carbonyl group in N-trifluoroacetylpiperidine and N-piperidine amides: Planar and non-planar nitrogen bond configurations. Tetrahedron 73 (35):5311-5320 Écija P, Uriarte I, Basterretxea FJ, Millán J, Lesarri A, Fernández JA, Cocinero EJ (2015) Structural distortion of the epoxy groups in norbornanes: a rotational study of exo-2,3epoxynorbornane. ChemPhysChem 16(12):2609-2614 (a) Giuliano BM, Melandri S, Caminati W (2017) Effects of deuteration of the methyl and phenyl hydrogens on the rotational spectrum of anisole-water. J Mol Spectrosc 337(1):86-89 (b) Giuliano BM, Caminati W (2005) Isotopomeric conformational change in anisole-water. Angew Chem 117(4):609-612; Angew Chem Int Ed 44(4):603-606 Pejlovas AM, Barfield M, Kukolich SG (2014) Microwave spectrum and molecular structure parameters for the 1,2-cyclohexanedione (monoenolic)-formic acid dimer. Chem Phys Lett 613:86-89 Durig JR, Ward RM, Conrad AR, Tubergen MJ, Nelson KG, Groner P, Gounev TK (2010) Microwave, Raman, and infrared spectra, r0 structural parameters, conformational stability, and vibrational assignment of cyanocyclohexane. J Mol Struct 967(1-3):99-111

764

9 Molecules with Seven to Nine Carbon Atoms

810 811 812

813 814 815

816 817 818 819 820 821 822

823 824

825 826 827 828 829

Zhou SX, Ward RM, Tubergen MJ, Gurusinghe RM, Durig JR (2013) Microwave, infrared, and Raman spectra, r0 structural parameters, conformational stability and ab initio calculations of cyclohexyl isocyanate. Chem Phys 415:44-55 Giuliano BM, Maris A, Melandri S, Caminati W (2009) Pure rotational spectrum and model calculations of anisole-ammonia. J Phys Chem A 113(52):14277-14280 Wallevik SÓ, Bjornsson R, Kvaran Á, Jonsdottir S, Girichev GV, Giricheva NI, Hassler K, Arnason I (2010) Conformational properties of 1-fluoro-1-methyl-silacyclohexane and 1methyl-1-trifluoromethyl-1-silacyclohexane: Gas electron diffraction, low-temperature NMR, temerature-dependent Raman spectroscopy, and quantum chemical calculations. J Mol Struct 978 (1-3):209-219 Shainyan BA, Kirpichenko SV, Shlykov SA, Kleinpeter E (2012) Structure and conformational properties of 1,3,3-trimethyl-1,3-azasilinane: Gas electron diffraction, dynamic NMR, and theoretical study. J Phys Chem A 116 (1):784-789 Bailey WC, Bohn RK, Dewberry CT, Grubbs GS, Cooke SA (2011) The structure and helicity of perfluorooctanonitrile, CF3-(CF2)6-CN. J Mol Spectrosc 270(1):61-65 (a) Campanelli AR, Domenicano A, Ramondo F, Hargittai I (2012) Molecular structure of pdiisocyanobenzene from gas-phase electron diffraction and theoretical calculations and effects of intermolecular interactions in the crystal on the benzene ring geometry. Struct Chem 23 (1):287-295 (b) Colapietro M, Domenicano A, Portalone G, Torrini I, Hargittai I, Schultz G (1984) Molecular structure and ring distotions of p-diisocyanobenzene in the gaseous phase and in the crystal. J Mol Struct 125:19-32 Pejlovas AM, Sun M, Kukolich SG (2014) Microwave measurements of the spectra and molecular structure for phthalic anhydride. J Mol Spectrosc 299:43-47 Rezaei M, Norooz Oliaee J, Moazzen-Ahmadi N, McKellar ARW (2016) Infrared spectra reveal box-like structures for a pentamer and hexamer of mixed carbon dioxide-acetylene clusters. Phys Chem Chem Phys 18(3):1381-1385 Jang H, Ka S, Peebles SA, Peebles RA, Oh JJ (2016) Microwave spectrum, structure and dipole moment of 3-fluorophenylacetylene (3FPA). J Mol Struct 1125:405-412 Jang H, Ka S, Dikkumbura AS, Peebles RA, Peebles SA, Oh JJ (2017) Microwave spectrum, structure and dipole moment of 4-fluorophenylacetylene (4FPA). J Mol Struct 1133:320-328 Belyakov AV, Nikolaenko KO, Davidovich PB, Ivanov AD, Garabadzhiu AV, Rykov AN, Shishkov IF (2017) Molecular structure of gaseous isatin as studied by electron diffraction and quantum chemical calculations. J Mol Struct 1132:44-49 Pejlovas AM, Lin W, Oncer O, Kukolich SG (2015) Microwave spectrum and the gas phase structure of phthalimide. J Mol Spectrosc 317(5):59-62 Vogt N, Savelyev DS, Giricheva NI, Islyaikin MK, Girichev GV (2016) Accurate determination of equilibrium structure of 3-aminophthalonitrile by gas electron diffraction and coupled-cluster computations: Structural effects due to intramolecular charge transfer. J Phys Chem A 120 (44):8853-8861 See 779(a). Akmeemana AG, Kang JM, Dorris RE, Nelson RD, Anderton AM, Peebles RA, Peebles SA, Seifert NA, Pate BH (2016) Effect of aromatic ring fluorination on CH⋅⋅⋅π interactions: microwave spectrum and structure of the 1,2-difluorobenzene⋅⋅⋅acetylene dimer. Phys Chem Chem Phys 18(35):24290-24298 Waerder B, Steinhauer S, Bader J, Neumann B, Stammler HG, Vishnevskiy YV, Hoge B, Mitzel NW (2015) Pentafluoroethyl-substituted α-silanes: model compounds for new insights. Dalton Trans 44 (29):13347-13358 Ulrich NW, Songer TS, Peebles RA, Peebles SA, Seifert NA, Pérez C, Pate BH (2013) Effect of aromatic ring fluorination on CH⋅⋅⋅π interactions: rotational spectrum and structure of the fluorobenzene⋅⋅⋅acetylene weakly bound dimer. Phys Chem Chem Phys 15(41):18148-18154 Kovtun DM, Kochikov IV, Tarasov YI (2015) Electron diffraction analysis for the molecules with multiple large-amplitude motions. 3-Nitrostyrene-a molecule with two internal rotors. J Phys Chem A 119 (9):1657-1665 Ulrich NW, Seifert NA, Dorris RE, Peebles RA, Pate BH, Peebles SA (2014) Benzene⋅⋅⋅acetylene: a structural investigation of the prototypical CH⋅⋅⋅π interaction. Phys Chem Chem Phys 16(19):8886-8894 Pejlovas AM, Daly AM, Ashe AJ, Kukolich SG (2016) Microwave spectra, molecular structure, and aromatic character of 4a,8a-azaboranaphthalene. J Chem Phys 144(11):114303/1-114303/10

9 References

765

830

Goswami M, Arunan E (2011) Microwave spectroscopic and theoretical studies on the phenylacetylene⋅⋅⋅H2O complex: C-H⋅⋅⋅O and O-H⋅⋅⋅π hydrogen bonds as equal partners. Phys Chem Chem Phys 13(31):14153-14162 Goswami M, Arunan E (2011) Microwave spectrum and structure of C6H5CCH⋅⋅⋅H2S complex. J Mol Spectrosc 268(1-2):147-156 See 794. Vogt N, Demaison J, Geiger W, Rudolph HD (2012) Microwave spectrum and equilibrium structure of o-xylene. J Mol Spectrosc 288:38-45 See 800. Dorofeeva OV, Shishkov IF, Rykov AN, Vilkov LV, Oberhammer H (2010) Molecular structure of 1,3-dimethoxybenzene as studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 978(1-3):35-40 Bird RG, Neill JL, Alstadt VJ, Young JW, Pate BH, Pratt DW (2011) Ground state 14N quadrupole couplings in the microwave spectra of N,N-dimethylaniline and 4,4dimethylaminobenzonitrile. J Phys Chem A 115(34):9392-9398 Kuze N, Ohno C, Morisaki S, Sugawara Y, Tamagawa K, Konaka S (2012) A study of the structure and conformation of 1,1-dicyclopropylethene by gas electron diffraction and ab initio calculations. J Mol Struct 1014:26-31 Durig JR, Ward RM, Conrad AR, Tubergen MJ, Nelson KG, Gounev TK (2010) Microwave, infrared, and Raman spectra, r0 structural parameters, conformational stability, and vibrational assignment of ethynylcyclohexane.” J Mol Struct 975(1-3):5-16 (a) Cocinero EJ, Lesarri A, Écija P, Grabow JU, Fernández JA, Castaño F (2010) N-Methyl stereochemistry in tropinone: the conformational flexibility of the tropane motif. Phys Chem Chem Phys 12(23):6076-6083 (b) Demaison J, Craig NC, Cocinero EJ, Grabow JU, Lesarri A, Rudolph HD (2012) Semiexperimental equilibrium structures for the equatorial conformers of N-methylpiperidone and tropinone by the mixed estimation method. J Phys Chem A 116(34):8684-8692 Melandri S, Maris A, Giuliano BM, Favero LB, Caminati W (2010) The free jet microwave spectrum of 2-phenylethylamine-water. Phys Chem Chem Phys 12(35):10210-10214 Gou Q, Feng G, Evangelisti L, Caminati W (2014) Interaction between freons and amines: the C-H...N weak hydrogen bond in quinuclidine-trifluoromethane. J Phys Chem A 118(4):737740 Sandwisch JW, Hedberg L, Hedberg K (2017) Molecular structure, equilibrium conformation, and ring-puckering motion in 1,1,3,3-tetramethylcyclobutane. An electron-diffraction investigation augmented by molecular orbital and normal coordinate calculations. J Phys Chem A 121 (32):6150-6154 Pérez C, López JC, Blanco S, Schnell M (2016) Water-induced structural changes in crown ethers from broadband rotational spectroscopy. J Phys Chem Lett 7(20):4053-4058 See 843. Wann DA, Robertson HE, Bramham G, Bull AEA, Norman NC, Russell CA, Rankin DWH (2009) Unusual chalcogen-boron ring compounds: The gas-phase structures of 1,4B4S2(NMe2)4 and related molecules. Dalton Trans 8:1446-1449 Trapp N, Scherer H, Hayes SA, Berger RJF, Kütt A, Mitzel NW, Saame J, Krossing I (2011) The perfluorinated alcohols (F5C6)(F3C)2COH and (F5C6)(F10C5)COH: Synthesis, theoretical and acidity studies, spectroscopy and structures in the solid state and the gas phase. Phys Chem Chem Phys 13 (13):6184-6191 Kolesnikova IN, Dorofeeva OV, Karasev NM, Oberhammer H, Shishkov IF (2014) Molecular structure and conformation of 1,3,5-tris(trifluoromethyl)-benzene as studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 1074:196-200 Berger RJF, Hoffmann M, Hayes SA, Mitzel NW (2009) An improved gas electron diffractometer - the instrument, data collection, reduction and structure refinement procedures. ZNaturforsch B 64 (11-12):1259-1268 Zinn S, Betz T, Medcraft C, Schnell M (2015) Structure determination of transcinnamaldehyde by broadband microwave spectroscopy. Phys Chem Chem Phys 17(24):16080-16085 Kolesnikova IN, Rykov AN, Shishkov IF, Tafeenko VA, Aslanov LA (2017) Molecular structure of clonidine: gas-phase electron diffraction, single-crystal X-ray diffraction and quantum chemical studies. Phys Chem Chem Phys 19 (6):4618-4626 Favero LB, Li W, Spadini G, Caminati W (2015) Ring puckering splitting and structure of indan. J Mol Spectrosc 316(10):45-48 See 836.

831 832 833 834 835 836 837 838 839

840 841 842

843 844 845 846

847 848 849 850 851 852

766

9 Molecules with Seven to Nine Carbon Atoms

853

854 855 856 857

858 859 860 861

Hnyk D, Samdal S, Exner O, Wann DA, Rankin DWH (2010) Does 2-methylacetophenone comply with steric inhibition of resonance? A direct experimental proof of its nonplanar conformation from a joint ab initio/electron diffraction analysis. J Org Chem 75 (15):49394943 Foerster T, Wann DA, Robertson HE, Rankin DWH (2009) Why are trimethylsilyl groups asymmetrically coordinated? Gas-phase molecular structures of 1-trimetylsilyl-1,2,3benzotriazole and 2-trimethylsilyl-1,3-thiazole. Dalton Trans 16:3026-3033

Neeman EM, Avilés-Moreno JR, Huet TR (2017) The quasi-unchanged gas-phase molecular structures of the atmospheric aerosol precursor β-pinene and its oxidation product nopinone. Phys Chem Chem Phys 19(4):13819-13827

Vallejo-López M, Écija P, Vogt N, Demaison J, Lesarri A, Basterretxea FJ, Cocinero EJ (2017) N-Methyl inversion and accurate equilibrium structures in alkaloids: Pseudopelletierine. Chem Eur J 23(65):16491-16496 Belyakov AV, Sigolaev Y, Shlykov SA, Wallevik SÓ, Jonsdottir NR, Bjornsson R, Jonsdottir S, Kvaran Á, Kern T, Hassler K, Arnason I (2015) Conformational properties of 1-tert-butyl-1silacyclohexane, C5H10SiH(t-Bu): gas-phase electron diffraction, temperature-dependent Raman spectroscopy, and quantum chemical calculations. Struct Chem 26 (2):445-453 Wann DA, Young S, Bätz K, Masters SL, Avent AG, Rankin DWH, Lickiss PD (2014) Structures of tetrasilylmethane derivatives C(SiXMe2)4 (X = H, F, Cl, Br) in the gas phase and their dynamic structures in solution. Z Naturforsch, B 69 (11-12):1321-1332 See 858. See 858. See 858.

Chapter 10. Molecules with Ten or More Carbon Atoms

862 CAS RN: 11121-63-4 MGD RN: 368272 GED supported by QC computations

1,1ꞌ,2,2ꞌ,3,3ꞌ,4,4ꞌ,5,5ꞌ-Decachloroferrocene C10Cl10Fe D5d Cl

Cl Cl

Cl

a

Distances Fe–C C–C C–Cl hb

ra [Å] 2.050(4) 1.434(3) 1.702(4) 1.648(4)

Dihedral angle

τa [deg] a

ϕ

c

Cl

Cl

Fe

Cl

Cl Cl Cl

-3.7(3) d

Reproduced with permission from The Royal Society of Chemistry. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2σ and a systematic error of 0.002r. b Distance between Fe and the ring plane. c Angle between the C−Cl bond and the ring plane. d Negative value when the C−Cl bond is bent away from the Fe atom. The GED experiment was carried out at Tnozzle = 433 K. The staggered conformation of the ligand rings was determined, whereas the eclipsed conformation was excluded. However, the barrier to internal rotation of the ligands around the C5 axis was determined to be very small (0.8(2) kJ mol−1), i.e. the ligands undergo virtually non-hindered internal rotation. Phillips L, Cooper MK, Haaland A, Samdal S, Giricheva NI, Girichev GV (2010) The molecular structure, equilibrium conformation and barrier to internal rotation in decachloroferrocene, Fe(η-C5Cl5)2, determined by gas electron diffraction. Dalton Trans 39 (19):4631-4635

863 CAS RN: 1643141-08-05 MGD RN: 465533 GED augmented by DFT computations Bonds Fe–C b Fe–C c C–H C–F C–C b C–C c

re [Å] a 2.071(1) 2.009(1) 1.085(7) 1.333(1) 1.425(1) 1.419(1)

© Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4_10

1,2,3,4,5-Pentafluoroferrocene C10H5F5Fe C5v (eclipsed)

F

Fe

F F

F F

767

768

Dihedral angles d

α βe

10 Molecules with Ten or More Carbon Atoms

θe [deg] a -3.7(1) 1.6(2)

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Carbon atom in the C5H5 ring. c Carbon atom in the C5F5 ring. d Angle between the C−F bond and the C5F5 ring plane, away from the Fe atom. e Angle between the C−H bond and the C5H5 ring plane, toward the Fe atom. b

PBE0/cc-pVTZ computations predicted only one conformer with C5v total symmetry and eclipsed conformation of the rings with respect to each other. The GED experiment was carried out at 330 K. Large-amplitude torsion around the C5 axis was described by a model of pseudo-conformers weighted according to computed PEF. Barrier to internal rotation was refined to be 2.4(8) kJ mol−1. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with quadratic and cubic force constants from computation at the level of theory as indicated above by taking into account nonlinear kinematic effects. Sünkel K, Weigand S, Hoffmann A, Blomeyer S, Reuter CG, Vishnevskiy YV, Mitzel NW (2015) Synthesis and characterization of 1,2,3,4,5-pentafluoroferrocene. J Am Chem Soc 137 (1):126-129

864 CAS RN: 1928-01-4 MGD RN: 539121 GED combined with MS and augmented by QC computations

1,5-Naphthalenedisulfonyl dichloride C10H6Cl2O4S2 C2 (I) Ci (II) O

O S

Bonds C–H C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(4a) C(1)–C(8a) C(8a)–C(4a) C–C C–S S–Cl S=O Bond angles C(8a)–C(1)–C(2) C(8a)–C(1)–S C(1)–S–Cl C–S=O O=S–Cl

a

rh1 [Å] I II 1.098(9) c 1.098(9) c d 1.376(3) 1.376(3) d d 1.408(3) 1.408(3) d d 1.373(3) 1.373(3) d d 1.422(3) 1.422(3) d 1.431(3) d 1.431(3) d d 1.440(3) 1.440(3) d c 1.405(3) 1.405(3) c 1.781(4) 1.781(4) 2.056(4) 2.056(4) 1.426(3) c 1.426(3) c

θh1 [deg] e

I 122.9(1) 122.7(3) 101.8(6) 109.3(4) c 106.2(2) c

II 122.9(1) 122.7(3) 101.8(6) 109.3(4) c 106.2(2) c

Cl

S

O O

Cl

10 Molecules with Ten or More Carbon Atoms

769

τh1 [deg] b,e

Dihedral angles C(8a)–C(1)–S–Cl C(4a)–C(5)–S–Cl C(4a)–C(8a)–C(1)–S

I 71.2(12) 71.2(12) 178.0(32)

II 71.2(12) -71.2(12) 178.0(32)

Copyright 2016 with permission from Elsevier.

I

II

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Absolute values of parameters for conformer II were assumed to be equal to those for conformer I. c Average value. d The C–C bond lengths were refined in one group; differences between these bond lengths were adopted from B3LYP/cc-pVTZ computation. e Parenthesized uncertainties in units of the last significant digit are 3σ values. Four conformers differing in the orientations of the two S–Cl bonds with respect to the ring plane were predicted by B3LYP and MP2 computations (with cc-pVTZ basis set). Two of these conformers, I and II, with the synperiplanar and antiperiplanar Cl–S…S–Cl dihedral angles, respectively, were detected by GED (Teffusion cell = 413(5) K) in approximately equal amounts. Vibrational corrections to the experimental internuclear distances, ∆rh1= ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Petrov VM, Giricheva NI, Ivanov SN, Petrova VN, Girichev GV (2017) Molecule 1,5-C10H6(SO2Cl)2 as prototype of conformational properties of naphthalene sulfonyl derivatives. J Mol Struct 1132:56-62

865 CAS RN: 85-46-1 MGD RN: 343984 GED combined with MS and augmented by QC computations

Bonds C–H C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(10) C(9)–C(10) C(1)–C(9)

rh1 [Å] a 1.082(6) 1.380(3) b 1.413(3) b 1.375(3) b 1.422(3) b 1.439(3) b 1.434(3) b

1-Naphthalenesulfonyl chloride α-Naphthalenesulfonyl chloride C10H7ClO2S C1

770

10 Molecules with Ten or More Carbon Atoms

C–C C–S S–Cl S=O

1.407(3) c 1.764(5) 2.051(5) 1.425(3)

Bond angles C(9)–C(1)–C(2) C(9)–C(1)–S C(1)–S–Cl C(1)–S=O O=S–Cl

θh1 [deg] d

Dihedral angles C(9)–C(1)–S–Cl C(10)–C(9)–C(1)–S

τh1 [deg] e

122.5(1) 122.1(5) 101.5(10) 110.2(7) c 106.4(3) c

71.4(21) 179.3(55)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with this superscript were refined in one group; differences between parameters were fixed at the values from B3LYP/cc-pVTZ computation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Parenthesized uncertainties in units of the last significant digit are 2.5σ values. The GED experiment was carried out at Teffusion cell = 370(5) K. Two conformers, I (C1 point-group symmetry) and II (Cs symmetry), characterized by the synclinal and antiperiplanar C(9)–C(1)–S–Cl torsional angles, respectively, were predicted at the MP2/cc-pVTZ level of theory to be separated by the barrier height of 5.7 kcal mol-1. The amount of the less stable conformer (II) was predicted to be negligible small (less than 1% at the temperature of the experiment). Vibrational corrections to the experimental internuclear distances, ∆ h1 = ra − rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Giricheva NI, Girichev GV, Dakkouri M, Ivanov SN, Petrov VM, Petrova VN (2013) Molecular structure and barriers to internal rotation of α-naphthalenesulfonyl chloride: A study by gas-phase electron diffraction and quantum chemical calculations. Struct Chem 24 (3):819-826

866 CAS RN: 93-11-8 MGD RN: 422140 GED combined with MS and augmented by QC computations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(10) C(9)–C(10) C(1)–C(9) C–C C–S

rh1 [Å] a 1.381(3) 1.422(3) b 1.379(3) b 1.430(3) b 1.440(3) b 1.425(3) b 1.411(3) c 1.757(5)

2-Naphthalenesulfonyl chloride β-Naphthalenesulfonyl chloride C10H7ClO2S C1

10 Molecules with Ten or More Carbon Atoms

S–Cl S=O C–H

2.053(4) 1.419(3) c 1.089(4) c

Bond angles C(1)–C(2)–C(3) C(1)–C(2)–S C(2)–S–Cl C(2)–S=O O=S–Cl

θh1 [deg] d

Torsional angles C(1)–C(2)–S–Cl C(9)–C(1)–C(2)–S

τh1 [deg] d

771

122.8(1) 118.5(8) 102.2(7) 110.1(5) c 106.7(2) c

108.2(32) -177.5(28)

Copyright 2013 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Difference to the C(1)–C(2) bond length was assumed at the value from B3LYP/cc-pVTZ calculation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. The GED experiment was carried out at Teffusion cell = 395(5) K. Two enantiomers with the C(1)–C(2)–S–Cl torsional angle close to 100 and 260°, respectively, were predicted by MP2 and B3LYP computations (in conjunction with up to cc-pVTZ basis set). The barrier to internal rotation of the sulfonyl chloride group around the C–S bond was calculated to be higher than 5 kcal mol-1, i.e. considerably exceeding the thermal energy at the temperature of the GED experiment. These enantiomers are indistinguishable by GED. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Giricheva NI, Petrov VM, Oberhammer H, Petrova VN, Dakkouri M, Ivanov SN, Girichev GV (2013) Interrelation of nonequivalent C-C bonds of naphthalene frame and spatial orientation of substituents: Betanaphthalene sulfonyl fluoride and beta-naphthalene sulfonyl chloride. J Mol Struct 1042:66-72

867 CAS RN: 325-12-2 MGD RN: 419541 GED combined with MS and augmented by QC computations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(10) C(9)–C(10) C(1)–C(9) C–C C–S S–F S=O

rh1 [Å] a 1.381(3) 1.422(3) b 1.378(3) b 1.429(3) b 1.439(3) b 1.424(3) b 1.410(3) c 1.753(6) 1.559(5) 1.414(4) c

2-Naphthalenesulfonyl fluoride β-Naphthalenesulfonyl fluoride C10H7FO2S C1

772

10 Molecules with Ten or More Carbon Atoms

C–H

1.097(7) c

Bond angles C(1)–C(2)–C(3) C(1)–C(2)–S C(2)–S–F C(2)–S=O O=S–F

θh1 [deg] d

Torsional angles C(1)–C(2)–S–F C(9)–C(1)–C(2)–S

τh1 [deg] d

122.8(3) 118.5(9) 103.3(30) 109.8(12) c 106.2(15) c

104.1(59) -176.5(66)

Copyright 2013 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Difference value to the C(1)–C(2) bond length was adopted from B3LYP/cc-pVTZ calculation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. The GED experiment was carried out at Teffusion cell = 350(5) K. Two enantiomers with the C(1)–C(2)–S–F torsional angle close to 100 and 260°, respectively, were predicted by MP2 and B3LYP computations (in conjunction with up to cc-pVTZ basis set). The barrier to internal rotation of the sulfonyl fluoride group around the C–S bond was calculated to be higher than 3 kcal mol-1, i.e. considerably exceeding the thermal energy at the temperature of the GED experiment. These enantiomers are indistinguishable by GED. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Giricheva NI, Petrov VM, Oberhammer H, Petrova VN, Dakkouri M, Ivanov SN, Girichev GV (2013) Interrelation of nonequivalent C-C bonds of naphthalene frame and spatial orientation of substituents: Betanaphthalene sulfonyl fluoride and beta-naphthalene sulfonyl chloride. J Mol Struct 1042:66-72

868 CAS RN: MGD RN: 341500 MW augmented by QC calculations

Benzene – 1,1,1,3,3,3-hexafluoro-2-(fluoromethoxy)propane (1/1) Benzene – sevoflurane (1/1) C10H9F7O C1 F F

Distances C(1)–F C(1)–H C(1)–O C(2)–O C(2)–H C(2)–C(3) C(2)–C(4) C(3)–F C(4)–F R1 b C–C C–H

r0 [Å]a 1.352(16) 1.086(17) 1.388(14) 1.406(10) 1.0936(48) 1.5222(89) 1.5222(89) 1.387(15) 1.387(15) 3.495(11) 1.390(13) c 1.085(13) c

F

O

F

rs [Å]a F

F F

1.402(20) 1.0974(70)

10 Molecules with Ten or More Carbon Atoms

Bond angles H–C(1)–H H–C(1)–F C(1)–O–C(2) O–C(2)–H H–C(2)–C(3) H–C(2)–C(4) C(3)–C(2)–C(4) F–C(3)–F F–C(4)–F F–C(3)–C(2) F–C(4)–C(2) C–C–C H–C–C

θ0 [deg] a

Dihedral angles

τ0 [deg] a 168.2(13) -168.6(11) -9.5(11) -47.79(99) 163.64(76) -177.75(70) 0.3(25)

ϕ

d

H–C(1)–O–C(2) C(1)–O–C(2)–H F–C(1)–C(2)–C(4) F–C(1)–C(2)–C(3) H–C(2)–C(4)–F

αe

113.6(17) 108.2(13) 115.56(74) 112.91(62) 108.30(56) 108.30(56) 114.37(47) 107.63(88) 107.63(88) 112.40(64) 112.40(64) 119.40(85) c 119.2(11) c

773

θs [deg] a

119.89(65) 120.54(44)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit. Distance between C(2) and the center-of-mass of the benzene subunit. c Average value for the benzene subunit. d Angle between C(2)–H and the center-of-mass of the benzene subunit. e Angle between O–C(2) and distance between C(1ꞌ) and the-center-of mass of the benzene subunit. b

The rotational spectrum was recorded by a broadband chirped-pulse FTMW spectrometer in the frequency range between 2 and 8 GHz. The partial rs and essentially complete r0 structures of the most stable conformer with 75 degrees of freedom were determined from the ground-state rotational constants of 46 isotopic species (main, six 13 C, six D and 33 13C/D). According to prediction of MP2/6-311++G(d,p) calculations, this conformer is lower in energy than the second low-energy conformer by 13.5 kJ mol-1. The geometry of the complex suggests that the main C(2)-H…π interaction is accompanied by secondary C–H…F weak contacts between three benzene hydrogens and the fluorine atoms in sevoflurane. Seifert NA, Zaleski DP, Pérez C, Neill JL, Pate BH, Vallejo-López M, Lesarri A, Cocinero EJ, Castaño Kleiner FI (2014) Probing the C-H⋅⋅⋅π weak hydrogen bond in anesthetic binding: the sevoflurane-benzene cluster. Angew Chem 126(12):3274-3277; Angew Chem Int Ed 53(12);3210-3213

869 CAS RN: 606-25-7 MGD RN: 447540 GED combined with MS and augmented by QC computations

Bonds C–H

rh1 [Å] a,b 1.089(4) 1

1-Naphthalenesulfonamide O O S

C10H9NO2S C1 (I) C1 (II)

NH2

774

10 Molecules with Ten or More Carbon Atoms

N–H C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(10) C(9)–C(10) C(1)–C(9) C–C C–S S–N S=O

1.023(4) 1 1.382(3) 2 1.418(3) 2 1.378(3) 2 1.426(3) 2 1.442(3) 2 1.438(3) 2 1.411(3) c 1.761(10) 1.666(10) 1.425(3) c

Bond angles C(9)–C(1)–C(2) C(9)–C(1)–S C(1)–S–N C(1)–S=O O=S–N

θh1 [deg] d

Dihedral angles C(9)–C(1)–S–N C(10)–C(9)–C(1)–S O(1)=S–N–H

119.8(2) 122.6(5) 104.5(22) 108.9(12) c 107.2(24) c

τh1 [deg] e 69.5(30) -179.8 f -24.4 g

Reprinted with permission. Copyright 2014 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5 σ values and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/cc-pVTZ computation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Parenthesized uncertainty in units of the last significant digit is 2.5σ value. f Assumed at the value from computation as indicated above. g Refined then fixed. MP2 and B3LYP computations in conjunction with cc-pVTZ basis set predicted existence of four conformers characterized by different C(9)–C(1)–S–N dihedral angles and/or different positions of the NH2 and SO2 groups with respect to each other. The GED experiment was carried out at Teffusion cell = 413(9) K. The best fit to the experimental intensities was obtained for a mixture of two conformers, I (75%) and II (25%). In both conformers the C(9)–C(1)–S–N dihedral angle is synclinal; the NH2 and SO2 groups are eclipsed in the predominant conformer and staggered in the minor conformer. Vibrational corrections to the experimental internuclear distances, ∆r = ra − rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Structural parameters are presented for conformer I. Giricheva NI, Petrov VM, Dakkouri M, Oberhammer H, Petrova VN, Shlykov SA, Ivanov SN, Girichev GV (2015) Structures and intriguing conformational behavior of 1-and 2-naphthalenesulfonamides as determined by gas-phase electron diffraction and computational methods. J Phys Chem A 119 (9):1502-1510

870 CAS RN: 1576-47-2 MGD RN: 447355

2-Naphthalenesulfonamide C10H9NO2S

10 Molecules with Ten or More Carbon Atoms

775

GED combined with MS and augmented by QC computations

C1 (I) C1 (II) O

Bonds C–H N–H C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(10) C(9)–C(10) C(1)–C(9) C–C C–S S–N S=O

rh1 [Å] a,b 1.083(5) 1 1.014(5) 1 1.380(3) 2 1.424(3) 2 1.378(3) 2 1.430(3) 2 1.439(3) 2 1.428(3) 2 1.411(3) c 1.780(7) 1.668(6) 1.427(4)

Bond angles C(1)–C(2)–C(3) C(1)–C(2)–S C(2)–S–N C(2)–S=O O=S–N

θh1 [deg] d

Dihedral angles C(1)–C(2)–S–N C(9)–C(1)–C(2)–S O(1)=S–N–Hʹ

τh1 [deg] e

O S NH2

123.0(3) 118.5(11) 103.6(19) 108.1(9) c 107.4(28) c

110(10) 178.7 f 9.9 f

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ values and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/cc-pVTZ computation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Parenthesized uncertainty in units of the last significant digit is 2.5σ value. f Assumed at the value from computation as indicated above. MP2 and B3LYP computations in conjunction with cc-pVTZ basis set predicted existence of two conformers, I and II, characterized by the synclinal C(3)–C(2)–S–N dihedral angle and differing in the orientations of the NH2 and SO2 groups with respect to each other. These groups are eclipsed in the lowest energy conformer I and staggered in the conformer II. The GED experiment was carried out at Teffusion cell = 431(9) K. The amounts of the conformers I and II were determined to be 75(8) and 25(8) %, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. The structural parameters were presented for the conformer I. Giricheva NI, Petrov VM, Dakkouri M, Oberhammer H, Petrova VN, Shlykov SA, Ivanov SN, Girichev GV (2015) Structures and intriguing conformational behavior of 1-and 2-naphthalenesulfonamides as determined by gas-phase electron diffraction and computational methods. J Phys Chem A 119 (9):1502-1510

776

10 Molecules with Ten or More Carbon Atoms

871 CAS RN: 63289-96-3 MGD RN: 381282 GED combined with MS and augmented by QC computations

Distances C(2)–C(1) C(2)=C(3) C(9)–C(10) C(6)–C(7) C(7)–C(8) C(8)–C(9) C(5)–C(6) C(5)–C(10) C(1)–C(5) C(3)–C(4) C(3)–O(2) C(1)=O(1) C(2)–H C(6)–H C(10)–H C(9)–H C(7)–H C(8)–H C(4)–H(2) C(4)–H(3) C(4)–H(4) O(1)…H(1) O(2)–H(1) O(1)...O(2)

rh1 [Å] a,b 1.443(3) 1 1.373(3) 1 1.392(3) 1 1.390(3) 1 1.396(3) 1 1.394(3) 1 1.403(3) 1 1.402(3) 1 1.498(3) 1 1.496(3) 1 1.308(3) 1.256(3) 1.080(4) 2 1.084(4) 2 1.084(4) 2 1.086(4) 2 1.086(4) 2 1.086(4) 2 1.091(4) 2 1.096(4) 2 1.096(4) 2 1.574(4) c 1.014(4) 2.507(5) c

Bond angles C(1)–C(2)=C(3) C(2)–C(1)=O(1) C(2)=C(3)–O(2) O(1)–C(1)–C(5) O(2)–C(3)–C(4) C(1)=O(1)–H(1) C(3)–O(2)–H(1) C(1)–C(5)–C(6) C(6)–C(5)–C(10) C(7)–C(6)–C(5) C(8)–C(7)–C(6) C(9)–C(8)–C(7) C(10)–C(9)–C(8) C(5)–C(10)–C(9) C(3)–C(4)–H(2) C(3)–C(4)–H(3) C(3)–C(4)–H(4)

θh1 [deg] d

Dihedral angles C(5)–C(1)–C(2)…O(1) C(4)–C(3)=C(2)…O(2) C(6)–C(5)–C(1)=O(1) H(2)–C(4)–C(3)–O(2)

τh1 [deg] d

120.1(8) 120.7(8) 122.1(8) 119.6(9) 116.6(9) 101.1 c 105.3 e 118.2(12) 118.8 e 120.6 e 120.1 e 119.8 e 120.1 e 120.6 e 111.7 e 109.7 e 109.7 e

179.5 e 179.9 e 0.2(80) 180.0 e

(2Z)-3-Hydroxy-1-phenyl-2-buten-1-one C10H10O2 C1 O

OH

CH3

10 Molecules with Ten or More Carbon Atoms

777

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from calculation at the level of theory as indicated below. c Dependent parameter. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Assumed at the value from calculation at the level of theory as indicated below. The GED experiment was carried out at Teffusion cell = 331(5) K. Benzoylacetone was found to exist as a mixture of two enol tautomers, (2Z)-3-hydroxy-1-phenyl-2-buten-1-one and (3Z)-4-hydroxy-4-phenyl-3-buten-2-one, in about equimolar amounts. In the title molecule, the enol ring was assumed to possess Cs local symmetry. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ calculation. Belova NV, Girichev GV, Oberhammer H, Trang NH, Shlykov SA (2012) Tautomeric and conformational properties of benzoylacetone, CH3-C(O)-CH2-C(O)-C6H5: Gas-phase electron diffraction and quantum chemical study. J Phys Chem A 116 (13):3428-3435

872 CAS RN: 62961-61-9 MGD RN: 382358 GED combined with MS and augmented by QC computations

Distances C(3)=C(4) C(3)–C(2) C(9)–C(10) C(6)–C(7) C(7)–C(8) C(8)–C(9) C(5)–C(6) C(5)–C(10) C(4)–C(5) C(2)–C(1) C(2)=O(2) C(4)–O(1) C(3)–H C(6)–H C(10)–H C(9)–H C(7)–H C(8)–H C(1)–Hʹ C(1)–Hʹʹ O(1)–H(1) O(2)…H(1) O(1)...O(2)

rh1 [Å] a,b 1.378(3) 1 1.439(3) 1 1.390(3) 1 1.391(3) 1 1.393(3) 1 1.395(3) 1 1.403(3) 1 1.403(3) 1 1.479(3) 1 1.512(3) 1 1.245(3) 1.313(3) 1.083(4) 2 1.086(4) 2 1.086(4) 2 1.088(4) 2 1.088(4) 2 1.088(4) 2 1.094(4) 2 1.099(4) 2 1.018(4) 2 1.578(4) c 2.520(5) c

Bond angles C(4)=C(3)–C(2)

θh1 [deg] d 120.9(7)

(3Z)-4-Hydroxy-4-phenyl-3-buten-2-one

OH

C10H10O2 C1 O

CH3

778

10 Molecules with Ten or More Carbon Atoms

C(3)=C(4)–O(1) C(3)–C(2)=O(2) O(1)=C(4)–C(5) O(2)=C(2)–C(1) C(4)–O(1)–H(1) C(2)=O(2)…H(1) C(4)–C(5)–C(6) C(6)–C(5)–C(10) C(7)–C(6)–C(5) C(8)–C(7)–C(6) C(9)–C(8)–C(7) C(10)–C(9)–C(8) C(5)–C(10)–C(9) C(2)–C(1)–Hʹ C(2)–C(1)–Hʹʹ

120.4(7) 121.8(7) 115.7(9) 120.6(9) 105.7 e 99.7 c 119.4(13) 118.7 e 120.5 e 120.2 e 119.7 e 120.2 e 120.6 e 109.7 e 109.0 e

Dihedral angles C(5)–C(4)=C(3)–O(1) C(1)–C(2)–C(3)–O(2) C(6)–C(5)–C(4)–O(1) Hʹ–C(1)–C(2)=O(2)

τh1 [deg] d 179(2) e 179.0 e 11.8(53) 24.6 e

Reprinted with permission. Copyright 2012 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from calculation at the level of theory as indicated below. c Dependent parameter. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Assumed at the value from calculation at the level of theory as indicated below. The GED experiment was carried out at Teffusion cell = 331(5) K. Benzoylacetone was found to exist as a mixture of two enol tautomers, (2Z)-3-hydroxy-1-phenyl-2-buten-1-one and (3Z)-4-hydroxy-4-phenyl-3-buten-2-one, in about equimolar amounts. In the title molecule, the enol ring was assumed to possess Cs local symmetry. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ calculation. Belova NV, Girichev GV, Oberhammer H, Trang NH, Shlykov SA (2012) Tautomeric and conformational properties of benzoylacetone, CH3-C(O)-CH2-C(O)-C6H5: Gas-phase electron diffraction and quantum chemical study. J Phys Chem A 116 (13):3428-3435

873 CAS RN: MGD RN: 460680 MW augmented by ab initio calculations

Distances

X(1)…H(6) C(1)–C(1ꞌ) C(1)–C(2) C(2)–C(3) C(3)–C(3ꞌ)

b

2,3-Dihydro-1H-indene – trifluoromethane (1/1) Indan – trifluoromethane (1/1) C10H11F3 Cs F

r0 [Å]a

2.39(1) 1.406 c 1.399 c 1.403 c 1.401 c

F

F

10 Molecules with Ten or More Carbon Atoms

C(1)–C(4) X(2)–C(5) d H(6)–C(7) C(7)–F(8) C(7)–F(9) F(9)...H(4) F(9)...H(5)

1.512 c 0.944 c 1.085 c 1.340 c 1.342 c 3.307 e 3.045 e

Angles

θ0 [deg] a

Dihedral angles

τ0 [deg]

C(1ꞌ)–C(1)–C(2) C(1)–C(2)–C(3) C(1ꞌ)–C(1)–C(4) H(6)–C(7)–F(8) H(6)–C(7)–F(9) X(2)…X(1)…H(6) b,d C(4)–H(4)…F(9) C(5)–H(5)…F(9) X(1)…X(2)…C(5) b,d X(1)…H(6)–C(7) b H(6)–C(7)–F(8) H(6)–C(7)–F(9)

X(1)…H(6)–C(7)–F(8) b H(6)–C(7)–F(8)…F(9)

779

120.5 c 119.0 c 110.1 c 110.9 c 110.7 c 91.8(6) 100.3 c 125.7 c 31.6 c 146.7 c 110.9 c 110.7 c

180.0 c 120.1 c

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit.

X(1) is the midpoint between C(2) and C(2ꞌ). c Assumed at the value from MP2/6-311++G** calculations. d X(2) is the midpoint between C(4) and C(4ꞌ). e Dependent parameter

The rotational spectra of the complex of indan with CHF3 and CDF3were recorded in a pulsed supersonic jet by an FTMW spectrometer in the frequency region between 6 and 18.5 GHz. The partial r0 structure was determined from the ground-state rotational constants of the main isotopic species; the remaining structural parameters were assumed at ab initio values (see above). Because of the reverse Ubbelohde effect the rotational constants of the indan-CDF3 species could not be used to derive structural information on the location of the hydrogen atom in the trifluoromethane subunit. The cage structure of the complex is formed due to the C-H…π interaction and two weak C-H…F hydrogen bonds Favero LB, Li W, Spada L, Evangelisti L, Visentin G, Caminati W (2015) The cage structure of indan-CHF3 is based on the cooperative effects of C-H⋅⋅⋅π and C-H⋅⋅⋅F weak hydrogen bonds. Chem Eur J 21(45):15970-15973

874 CAS RN: 61-54-1 MGD RN: 152147 GED augmented by QC computations

Bonds C(2)–N(1) C(7a)–N(1)

1H-Indole-3-ethanamine Tryptamine C10H12N2 C1 (all conformers) NH2

– +

gg 1.380(6) 1 1.374(6) 1

– –

gg

rh1 [Å] a,b g+a 1.380(6) 1 1.374(6) 1

g+g–

N H

780

10 Molecules with Ten or More Carbon Atoms

1.368(6) 1 1.420(3) 2 1.433(17) 3 1.403(3) 2 1.385(3) 2 1.407(3) 2 1.386(3) 2 1.395(3) 2 1.491(12) 4 1.527(12) 4 1.475(26) 5

C(3)–C(2) C(3a)–C(7a) C(3a)–C(3) C(4)–C(3a) C(5)–C(4) C(6)–C(5) C(7)–C(6) C(7)–C(7a) C(10)–C(3) C(9)–C(10) N(8)–C(9) Bond angles

– +

gg 109.1(7) 6 110.3(7) 6 118.8(8) 7 119.4(8) 7 124.3(23) 8 126.6 c 112.9(28) 9 106.8(38) 10

C(7a)–N(1)–C(2) C(3)–C(2)–N(1) C(4)–C(3a)–C(7a) C(5)–C(4)–C(3a) C(6)–C(5)–C(4) C(10)–C(3)–C(2) C(9)–C(10)–C(3) N(8)–C(9)–C(10) Dihedral angles

– +

C(9)–C(10)–C(3)–C(3a) N(8)–C(9)–C(10)–C(3)

gg -72(5) 12 -77(8) 13

1.395(3) 2 1.489(12) 4 1.538(12) 4 1.471(26) 5

– –

gg

8

113.0(28) 9 112.5(38) 10

gg

-76(8) 13

1.421(3) 2 1.433(17) 3

1.492(12) 4 1.537(12) 4 1.470(26) 5

θh1 [deg] a,b

124.2(23)

– –

1.370(6) 1 1.420(3) 2 1.434(17) 3 1.404(3) 2 1.385(3) 2 1.407(3) 2 1.386(3) 2 1.396(3) 2 1.493(12) 4 1.527(12) 4 1.475(26) 5

g+a 109.1(9) 110.3(9) 118.8(8) 7 119.2(8) 7 119.8(18) 126.6 c 113.9(28) 9 107.8(25) 11

g+g–

119.5(8) 7 119.9(18) 113.5(28) 9 113.2(25) 11

τh1 [deg] a,b

g+a -79(5) 12 53(8) 13

g+g– -86(5) 12 49(8) 13

Copyright 2017 with permission from Elsevier.

g–g+

g –g –

g+a a

g+g–

Parenthesized uncertainties in units of the last significant digit are 3σ values.

10 Molecules with Ten or More Carbon Atoms

781

b

Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from B3LYP/cc-pVTZ computation. The values of the C−H and N−H bond lengths as well as the C−C−H and C−N−H angles were also adopted from computation. c Assumed at the value from computation as above. Eight conformers differing in the conformations of the N(8)–C–C–C and H–N(8)–C–C chains were predicted by computations at the MP2 and B3LYP levels of theory in conjunction with cc-pVTZ basis set. According to MP2 predictions, four of these conformers may exist in remarkable amounts at the temperature of the GED experiment (Tnozzle = 405 K). Each of these four conformers possesses the synclinal N(8)–C–C–C dihedral angle (labelled by the first letter g– or g+) and the synclinal (g– or g+) or antiperiplanar (a) H–N(8)–C–C chain (labelled by the second letter g–, g+ or a). In the final GED refinement, the ratio of the conformers was fixed as follows: g–g+: g–g–: g+a : g+g– = 35 : 35 : 20 :10 (in %) being close to that predicted at the MP2 level of theory. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP computation. Marochkin, II, Altova EP, Rykov AN, Shishkov IF (2017) Molecular structure of tryptamine in gas phase according to gas electron diffraction method and quantum chemistry calculations. J Mol Struct 1148:179-184

875 CAS RN: 13078-04-1 MGD RN: 216424 MW augmented by QC calculations

Bonds N(1)–C(6) C(6)–C(5) C(5)–C(4) C(4)–C(3) C(3)–C(2) C(2)–C(3') C(3')–C(2') C(2')–N(1') N(1')–C(6') C(6')–C(5') C(5')–C(4') Bond angles C(3')–C(2)–C(3) C(2')–C(3')–C(2) C(5)–C(6)–N(1) C(4)–C(5)–C(6) C(3)–C(4)–C(5) C(2)–C(3)–C(4) N(1')–C(2')–C(3') C(6')–N(1')–C(2') C(5')–C(6')–N(1') C(4')–C(5')–C(6') Dihedral angles

3-(2-Piperidinyl)pyridine Anabasine C10H14N2 C1

eq-eq-syn 1.467 b 1.526 b 1.531 b 1.531 b 1.534 b 1.505 b 1.402 b 1.345 b 1.345 b 1.400 b 1.396 b

eq-eq-syn 113.68 121.93 109.35 b 110.11 b 110.26 b 110.68 b 124.54 b 116.67 b 123.57 b 118.89 b

eq-eq-syn

r0 [Å] eq-eq-anti 1.466 b 1.526 b 1.531 b 1.531 b 1.534 b 1.506 b 1.406 b 1.345 b 1.346 b 1.399 b 1.397 b

θ0 [deg] a

eq-eq-anti 111.56 122.9 109.28 b 110.11 b 110.31 b 110.63 b 124.19 b 116.97 b 123.61 b 118.58 b

τ0 [deg]a

eq-eq-anti

N H N

782

10 Molecules with Ten or More Carbon Atoms

C(2')–C(3')–C(2)–C(3) C(4)–C(5)–C(6)–N(1) C(3)–C(4)–C(5)–C(6) C(2)–C(3)–C(4)–C(5) C(3')–C(2)–C(3)–C(4) N(1')–C(2')–C(3')–C(2) C(6')–N(1')–C(2')–C(3') C(5')–C(6')–N(1')–C(2') C(4')–C(5')–C(6')–N(1')

-103.14 57.91 b -54.12 b 54.17 b -178.39 b 177.05 b 1.74 b -1.07 b 0.00 b

77.18 57.90 b -54.06 b 54.11 b -178.67 b 178.38 b 0.28 b -0.40 b 0.22 b

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Uncertainties were not given in the original paper. Fixed to the MP2/6-311++G(d,p) value.

eq-eq-syn

eq-eq-anti

The rotational spectrum of the title compound was recorded in a supersonic jet by an FTMW spectrometer in the frequency range between 6 and 26 GHz. Two conformers, equatorial-equatorial-syn and equatorial-equatorial-anti, differing by the synclinal and anticlinal H-C(2)-C(3ꞌ)-C(2ꞌ) torsional angles were identified. These two conformers, characterized by equatorial positions of the N–H bond and the pyridine moiety with respect to the piperidinyl ring, were predicted by ab initio to be the lowest energy conformers with energy difference 3.1 kJ mol-1 and interconversion barrier of 18.1 kJ mol-1. The population ratio in the jet was estimated to be eq-eq-syn/eq-eq-anti ≈ 5(2) from relative intensity measurements. For each conformer, three structural parameters defining the orientation of the pyridine ring were determined from the ground-state rotational constants of the main isotopic species; the remaining structural parameters were assumed at the ab initio values (see above). Lesarri A, Cocinero EJ, Evangelisti L, Suenram RD, Caminati W, Grabow JU (2010) The conformational landscape of nicotinoids: Solving the conformational disparity of anabasine. Chem Eur J 16(33):10214-10219

876

6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-carboxaldehyde 6,6-Dimethyl-2-norpinene-2-carboxaldehyde Myrtenal C10H14O

CAS RN: 564-94-3

MGD RN: 541325 MW augmented by QC calculations

C1 (s-trans) O

Bonds C(1)–C(2) C(2)=C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(5)–C(7) C(6)–C(8) C(6)–C(9) C(2)–C(10)

r0 [Å] a 1.502(16) 1.341(16) 1.516(9) 1.547(11) 1.560(11) 1.553(12) 1.534(11) 1.531(19) 1.479(9)

rs [Å] a 1.508(3) 1.540(3) 1.546(4) 1.559(4) 1.532(4) 1.541(6)

H 3C H3C

H

10 Molecules with Ten or More Carbon Atoms

C(10)=O

1.220(13)

Bond angles C(1)–C(2)=C(3) C(2)=C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(4)–C(5)–C(7) C(1)–C(7)–C(5) C(2)–C(1)–C(7) C(5)–C(6)–C(8) C(5)–C(6)–C(9) C(3)=C(2)–C(10) C(2)–C(10)=O

θ0 [deg] a

Dihedral angles

τ0 [deg] a

C(1)–C(2)=C(3)–C(4) C(2)=C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6) C(3)–C(4)–C(5)–C(7) C(4)–C(5)–C(6)–C(8) C(4)–C(5)–C(6)–C(9) C(4)–C(3)=C(2)–C(10) C(3)=C(2)–C(10)=O

118.81(61) 118.49(38) 110.09(36) 110.73(71) 108.12(61) 85.79(48) 105.43(79) 111.77(98) 119.2(10) 119.3(11) 124.4(13)

b

1.86 -2.6(10) 48.9(12) -45.7(11) 167.1(11) 39.95(67) -177.3(19) 178.3(18)

783

θs [deg] a 110.20(15) 111.46(27) 107.93(21) 112.40(31) 118.65(31)

τs [deg] a 47.73(41) -46.32(38) 167.01(37) 40.64(26)

Copyright 2017 with permission from Elsevier.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Assumed at the value from B3LYP/6-311++G(d,p) calculations.

The rotational spectrum of myrtenal was recorded by a pulsed-jet FTMW spectrometer in the frequency region between 2 and 20 GHz. Only the s-trans conformer was observed. The r0 structure of the heavy-atom skeleton was obtained from the ground-state rotational constants of twelve isotopic species (main, 18O and ten 13C); the structural parameters involving H atoms were fixed according to DFT calculations (see above). The rs structure was determined for the carbon skeleton. Chrayteh M, Dréan P, Huet TR (2017) Structure determination of myrtenal by microwave spectroscopy and quantum chemical calculations. J Mol Spectrosc 336(2):22-28

877 CAS RN: 18309-32-5 MGD RN: 359804 MW supported by DFT calculations

Bonds C(4)–C(5) C(4)–C(10) C(4)=C(3) C(3)–C(2) C(1)–C(2) C(1)–C(7)

(1R,5R)-4,6,6-Trimethylbicyclo[3.1.1]hept-3-en-2-one (1R,5R)-2-Pinen-4-one Verbenone C10H14O C1 H 3C

a

r0 [Å] 1.510(41) 1.496(26) 1.343(47) 1.480(42) 1.522(44) 1.569(50)

a

rs [Å] 1.454(31) 1.499(13) 1.328(14) 1.494(13) 1.518(33) 1.538(13)

O

H 3C

CH3

784

10 Molecules with Ten or More Carbon Atoms

C(1)–C(6) C(6)–C(8) C(6)–C(9) C(5)–C(6) C(5)–C(7) C(2)=O

1.565(40) 1.528(34) 1.538(24) 1.574(39) 1.568(47) 1.219(21)

1.5542(69) 1.5432(61) 1.524(13) 1.606(11) 1.590(14) 1.220(17)

Bond angles C(3)=C(4)–C(10) C(2)–C(3)=C(4) C(3)–C(2)=O C(2)–C(1)–C(7) C(2)–C(1)–C(6) C(1)–C(6)–C(8) C(1)–C(6)–C(5) C(8)–C(6)–C(9) C(8)–C(6)–C(5) C(9)–C(6)–C(5) C(6)–C(5)–C(4) C(3)=C(4)–C(5) C(5)–C(4)–C(10) C(1)–C(2)=O C(1)–C(2)–C(3) C(4)–C(5)–C(7) C(7)–C(5)–C(6) C(6)–C(1)–C(7) C(1)–C(6)–C(9) C(5)–C(7)–C(1)

θ0 [deg] a

θs [deg] a

124.1(17) 118.0(18) 123.8(28) 106.8(24) 109.8(22) 118.3(29) 85.3(18) 108.1(20) 120.1(24) 111.9(24) 110.1(17) 117.1(19) 118.8(18) 122.5(24) 113.7(19) 107.2(22) 87.2(22) 87.5(24) 111.7(23) 85.3(13)

123.7(19) 117.5(12) 123.6(24) 107.5(22) 109.5(24) 118.16(52) 84.97(42) 106.3(19) 118.2(59) 114.9(13) 110.9(22) 118.2(12) 118.1(11) 123.0(14) 113.3(12) 109.0(21) 84.59(50) 88.12(62) 113.7(14) 86.06(16)

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectrum of verbenone was recorded by two chirped-pulse FTMW spectrometers in the frequency region between 2 and 18 GHz and by a free jet Stark-modulated spectrometer between 48 and 72 GHz. The r0 and rs structures were determined for the heavy-atom skeleton from the ground-state rotational constants of twelve isotopic species (main, 18O and ten 13C). The determined r0 structure was found to be in excellent agreement with the re one from B3LYPD3BJ/6-311++G(d,p) calculation. Marshall FE, Sedo G, West C, Pate BH, Allpress SM, Evans CJ, Godfrey PD, McNaughton D, Grubbs GS (2017) The rotational spectrum and complete heavy atom structure of the chiral molecule verbenone. J Mol Spectrosc 342(6):109-115

878 CAS RN: 14024-63-6 MGD RN: 750995 GED combined with MS and augmented by DFT computations

Bis(2,4-pentanedionato-κO,κO')zinc Bis(acetylacetonato)zinc C10H14O4Zn D2d (see comment) H 3C

CH3

O

Distances Zn–O O–C C–C(r) C–C(m)

rh1[Å] a 1.942(4) b 1.279(3) b 1.398(3) b 1.504(5) b

O Zn

O H 3C

O CH3

10 Molecules with Ten or More Carbon Atoms

C(m)–H C(m)–H' C(r)–H O…O Zn…C Zn…C(r) Zn…C(m)

1.071(5) b 1.071(5) c 1.060(5) c 2.823(9) 2.885(6) 3.239(8) 4.238(9)

Bond angles O–Zn–O Zn–O–C C–C(r)–C O–C–C(m) H–C(m)–C H'–C(m)–C e

θh1 [deg] d

Dihedral angle

τh1 [deg] d

γ

f

785

93.2(7) b 125.9(7) b 125.8(14) 115.2(9) b 107.0(20) 108.5(20) b

32.7(48) b

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Refined parameter. c Difference to the C(m)–H bond length was assumed at the value from computation at the level of theory as indicated below. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Methyl group tilts away from the C–C(r) bond. f Torsion angle of the methyl group; γ = 0° when the C(m)–H' bond is eclipsed with respect to the C–C(r) bond. The GED experiment was carried out at Teffusion cell = 376(7) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Rotation of the methyl groups was identified as free due to effective value of torsional angle γ ≈ 30°. Antina EV, Belova NV, Berezin MB, Girichev GV, Giricheva NI, Zakharov AV, Petrova AA, Shlykov SA (2009) Structures and energetics of β-diketonates. XVI. Molecular structure and vibrational spectrum of zinc acetylacetonate according to gas-phase electron diffraction and quantum-chemical calculations. J Struct. Chem (Engl Transl)/Zh Strukt Khim 50/50(6/6):1035-1045/1084-1094

879 CAS RN: 79-92-5 MGD RN: 483483 MW augmented by QC calculations

2,2-Dimethyl-3-methylenebicyclo[2.2.1]heptene Camphene C10H16 C1 CH3 CH3

Bonds C(1)–C(2) C(3)–C(5) C(4)–C(3) C(6)–C(7) C(7)=C(8)

r0 [Å] a 1.556(5) 1.550(7) 1.546(6) 1.527(5) 1.340(6)

rs [Å] a 1.551(4) 1.561(11) 1.547(4)

r

(1) m

[Å]

1.553(5) 1.546(4) 1.545(5) 1.519(3) 1.343(5)

a CH2

786

10 Molecules with Ten or More Carbon Atoms

C(2)–C(7) C(6)–C(9) C(6)–C(10) C(3)–C(6) C(2)–C(5) C(1)–C(4)

1.510(8) 1.541(10) 1.543(12) 1.555(7) 1.544(6) 1.562(5)

1.535(12) 1.556(3)

1.494(7) 1.544(7) 1.535(8) 1.545(4) 1.540(4) 1.554(4)

Bond angles C(3)–C(5)–C(2) C(1)–C(4)–C(3) C(2)–C(1)–C(4) C(4)–C(3)–C(5) C(1)–C(2)–C(5) C(5)–C(2)–C(7) C(6)–C(7)=C(8) C(7)–C(6)–C(9) C(3)–C(6)–C(10) C(9)–C(6)–C(10) C(2)–C(7)–C(6) C(5)–C(3)–C(6) C(4)–C(3)–C(6) C(3)–C(6)–C(7) C(1)–C(2)–C(7) C(2)–C(7)=C(8) C(3)–C(6)–C(9) C(7)–C(6)–C(10)

θ0 [deg] a

θs [deg] a

θ (1) [deg] a m

Dihedral angles C(1)–C(2)–C(7)=C(8) C(1)–C(2)–C(7)–C(6) C(2)–C(7)–C(6)–C(3) C(2)–C(7)–C(6)–C(10) C(4)–C(3)–C(6)–C(9) C(4)–C(3)–C(6)–C(7) C(5)–C(3)–C(6)–C(7)

94.2(2) 103.1(3) 103.1(3) 99.9(3) 101.1(3) 101.0(6) 126.4(6) 111.7(9) 113.9(6) 107.7(3) 106.9(5) 101.8(5) 110.8(6) 101.1(4) 107.1(9) 126.7(3) 110.2(9) 112.2(15)

τ0 [deg] a

-109.3(20) 71.5(17) -1.25(21) -123.0(11) 172.0(4) -69.6(15) 35.9(14)

94.0(2) 103.2(1) 103.1(1) 99.5(2) 101.3(4)

τs [deg] a

94.1(2) 103.2(2) 103.1(2) 99.7(2) 101.1(2) 100.9(4) 125.8(4) 111.5(6) 114.1(4) 107.5(2) 107.3(4) 102.0(3) 110.6(5) 101.0(3) 107.3(5) 126.9(2) 109.7(6) 113.0(10)

τ (1) [deg] a m

-109.0(14) 70.9(11) -0.6(13) –122.8(7) 172.2(2) -70.0(10) 35.3(10)

Copyright 2016 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 2 and 20 GHz. The main and all singly substituted 13C isotopic species were studied in natural abundance. The determination of the r0 and rm(1) carbon skeleton structures was based on the B3LYP/6-311++G(2df,p) and MP2/aug-cc-pVTZ equilibrium structures, respectively. Neeman EM, Dréan P, Huet TR (2016) The structure and molecular parameters of camphene determined by Fourier transform microwave spectroscopy and quantum chemical calculations. J Mol Spectrosc 322(14):50-54

10 Molecules with Ten or More Carbon Atoms

787

880 CAS RN: 80-56-8 MGD RN: 663598 MW augmented by DFT calculations

2,6,6-Trimethylbicyclo[3.1.1]hept-2-ene α-Pinene C10H16 C1 H 3C

Bonds C(2)=C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(2)–C(10) C(5)–C(7) C(6)–C(8) C(6)–C(9) C(1)–C(2) C(1)–C(7)

r0 [Å] a 1.349(15) 1.509(7) 1.545(8) 1.558(10) 1.567(12) 1.500(6) 1.554(12) 1.527(13) 1.538(8) 1.512(16) 1.565(7)

rs [Å] a 1.332(10) 1.517(5) 1.529(6) 1.547(5)

Bond angles C(2)=C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(1)–C(6)–C(5) C(10)–C(2)=C(3) C(4)–C(5)–C(7) C(5)–C(6)–C(8) C(1)–C(6)–C(9) C(1)–C(2)–C(10) C(8)–C(6)–C(9) C(1)–C(6)–C(8) C(5)–C(6)–C(9) C(5)–C(7)–C(1) C(7)–C(5)–C(6) C(2)–C(1)–C(7) C(1)–C(2)=C(3) C(2)–C(1)–C(6) C(7)–C(1)–C(6) C(6)–C(1)–C(5) C(5)–C(1)–C(7)

θ0 [deg] a

θs [deg] a

Dihedral angles C(2)=C(3)–C(4)–C(5) C(1)–C(2)=C(3)–C(4) C(4)–C(5)–C(6)–C(1) C(3)–C(4)–C(5)–C(6) C(3)–C(4)–C(5)–C(7) C(4)–C(5)–C(6)–C(9) C(4)–C(5)–C(6)–C(8) C(10)–C(2)=C(3)–C(4) C(5)–C(1)–C(2)–C(4) C(10)–C(1)–C(2)=C(3)

τ0 [deg] a

119.5(4) 110.4(3) 110.7(6) 85.4(6) 123.7(12) 108.0(6) 119.4(10) 111.6(8) 119.4(11) 108.1(6) 119.1(5) 111.9(7) 85.6(3) 87.8(6) 106.5(7) 116.9(5) 110.2(10) 87.1(6) 47.1(4) 47.0(4)

-1.9(18) 1.3(24) -80.6(7) 48.5(10) -46.1(7) 168.0(9) 40.3(7) -177.8(13) 0.5(7) -179.1(35)

Reproduced with permission of AIP Publishing.

1.506(4) 1.561(7) 1.543(8) 1.532(4)

119.4(2) 110.3(1) 111.7(4) 124.0(6) 108.3(5) 118.3(5) 107.4(3) 112.8(3) 87.0(3)

τs [deg] a -2.2(9)

47.9(5) -46.2(3) 167.2(4) 40.7(4) -177.8(9)

r (1) [Å] a m 1.340(18) 1.507(10) 1.541(15) 1.547(14) 1.558(20) 1.500(7) 1.559(15) 1.536(20) 1.530(12) 1.506(22) 1.600(12)

θ (1) [deg] a m 119.5(5) 110.6(4) 111.5(11) 86.0(9) 123.6(14) 107.8(6) 118.5(15) 112.7(13) 119.4(13) 107.4(9) 118.7(8) 112.6(11) 85.5(5) 87.0(9) 107.0(11) 117.0(6) 110.7(12) 86.6(10) 46.8(6) 47.2(6)

τ (1) [deg] a m

-1.4(22) 1.4(28) -79.3(12) 47.4(18) -46.5(10) 167.8(11) 41.3(15) -178.0(11) 0.1(8) -179.4(40)

CH3

CH3

788 a

10 Molecules with Ten or More Carbon Atoms

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of α-pinene were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 2 and 20 GHz. The partial r0 structure of the carbon skeleton was determined from the ground-state rotational constants of eleven isotopic species (main and ten 13C); the structural parameters involving H atoms were constrained to B3LYP/6-311++G(2df,p) values. The partial rs and r (1) structures were also determined. m Neeman EM, Avilés-Moreno JR, Huet TR (2017) The gas phase structure of α-pinene, a main biogenic volatile organic compound. J Chem Phys 147(21):214305/1-214305/7 https://doi.org/10.1063/1.5003726

881 CAS RN: 127-91-3 MGD RN: 507006 MW supported by QC calculations

6,6-Dimethyl-2-methylenebicyclo[3.3.1]heptane ß-Pinene C10H16 C1 H 3C

H 3C

Bonds C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(1)–C(6) C(2)=C(10) C(7)–C(5) C(6)–C(8) C(6)–C(9) C(1)–C(2) C(1)–C(7)

r0 [Å] a 1.525(8) 1.548(6) 1.541(8) 1.556(9) 1.578(10) 1.340(5) 1.556(12) 1.524(12) 1.537(7) 1.495(11) 1.562(6)

r (1) [Å] a m 1.513(10) 1.546(7) 1.530(12) 1.546(10) 1.561(15) 1.339(5) 1.563(13) 1.538(16) 1.526(9) 1.491(13) 1.556(8)

Bond angles C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(1)–C(6)–C(5) C(10)=C(2)–C(3) C(4)–C(5)–C(7) C(5)–C(6)–C(8) C(1)–C(6)–C(9) C(1)–C(2)=C(10) C(8)–C(6)–C(9) C(8)–C(6)–C(1) C(5)–C(6)–C(9) C(5)–C(7)–C(1) C(7)–C(5)–C(6) C(2)–C(1)–C(7) C(1)–C(2)–C(3) C(2)–C(1)–C(6) C(7)–C(1)–C(6)

θ0 [deg] a

θ (1) [deg] a m

Dihedral angles C(2)–C(3)–C(4)–C(5)

τ0 [deg] a

τ (1) [deg] a m

113.4(2) 111.3(3) 110.8(6) 85.7(5) 122.5(5) 108.9(5) 119.6(8) 111.3(10) 123.3(6) 108.7(6) 118.0(5) 112.0(6) 86.3(4) 88.1(6) 109.3(6) 114.2(4) 108.9(6) 87.0(5)

-21.6(9)

113.4(2) 111.5(4) 111.9(9) 86.6(8) 123.2(6) 108.5(5) 118.1(11) 112.9(12) 123.2(6) 107.9(7) 117.7(6) 112.8(7) 86.1(3) 86.8(8) 109.7(7) 114.2(4) 109.5(7) 86.6(7)

–21.5(9)

CH2

10 Molecules with Ten or More Carbon Atoms

C(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–C(1) C(6)–C(1)–C(2)=C(10) C(3)–C(4)–C(5)–C(7) C(2)–C(1)–C(6)–C(8) C(2)–C(1)–C(6)–C(9) C(4)–C(5)–C(6)–C(8) C(7)–C(1)–C(6)–C(5) C(10)=C(2)–C(3)–C(4) C(10)=C(2)–C(3)–C(1)

58.6(9) -82.7(8) 118.8(12) -36.6(5) -38.6(9) -165.3(6) 37.2(7) -26.6(5) -155.8(8) -179.5(5)

789

57.1(13) -81.0(15) 119.2(11) -37.0(5) -38.1(9) -164.8(7) 38.7(10) -27.8(8) -156.0(8) -180.3(16)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of ß-pinene were recorded in a supersonic jet by an FTMW spectrometer in the frequency region between 2 and 20 GHz. structures were determined from the ground-state rotational constants of eleven isotopic The partial r0 and r (1) m species (main and ten 13C).

Neeman EM, Avilés-Moreno JR, Huet TR (2017) The quasi-unchanged gas-phase molecular structures of the atmospheric aerosol precursor β-pinene and its oxidation product nopinone. Phys Chem Chem Phys 19(4):13819-13827

882 CAS RN: 1195-79-5 MGD RN: 494368 MW augmented by ab initio calculations

1,3,3-Trimethylbicyclo[2.2.1]heptan-2-one Fenchone C10H16O C1 CH3

Bonds C(1)–C(6) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(7)–C(1) C(7)–C(4) C(8)–C(1) C(9)–C(3) C(10)–C(3) O=C(2)

r0 [Å] a 1.555(18) 1.526(29) b 1.535(31) 1.549(30) 1.546(8) 1.562(9) 1.541(25) 1.552(8) b 1.521(11) 1.545(16) 1.535(13) 1.214(5)

rs [Å] a 1.521(13) 1.512(11) 1.545(14) 1.565(17) 1.531(4) 1.566(5) 1.536(13) 1.541(3) 1.537(7) 1.568(18) 1.504(18) 1.213(3)

Bond angles C(1)–C(6)–C(5) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(7)–C(1)–C(6) O=C(2)–C(3) C(8)–C(1)–C(6) C(9)–C(3)–C(4)

θ0 [deg] a

θs [deg] a

103.9(7) 107.5(12) b 100.8(9) 110.3(8) 102.8(3) 101.4(11) 125.8(31) 115.3(11) 111.4(14)

103.6(3) 107.2(7) 99.7(4) 109.3(8) 102.46(15) 103.0(7) 124.5(13) 115.9(5) 109.6(13)

CH3 H 3C

O

790

10 Molecules with Ten or More Carbon Atoms

C(10)–C(3)–C(4) C(1)–C(7)–C(4)

116.2(22) 95.2(6) b

117.4(13) 94.4(3)

Dihedral angles C(2)–C(3)–C(4)–C(5) C(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–C(1) C(7)–C(1)–C(6)–C(5) C(8)–C(1)–C(6)–C(5) C(9)–C(3)–C(4)–C(7) C(10)–C(3)–C(4)–C(2) O=C(2)–C(3)–C(4)

τ0 [deg] a

τs [deg] a

70.2(13) –67.3(10) -5.9(9) -30.3(7) -160.6(16) 80.4(11) -119.7(15) -177.7(10)

72.3(11) –68.1(5) -5.7(5) -30.3(4) -161.0(7) 79.8(6) -122.2(18) -178.3(6)

Reproduced with permission of AIP Publishing.

a b

Parenthesized uncertainties in units of the last significant digit. Dependent parameter.

The rotational spectrum of fenchone was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8 GHz. The partial r0 structure of the heavy-atom skeleton was determined from the ground-state rotational constants of twelve isotopic species (main, ten 13C and 18O); the remaining structural parameters were constrained to the values from MP2/6-311++G(d,p) calculations. The partial rs structure was also obtained for the heavy-atom skeleton. Loru D, Bermúdez MA, Sanz ME (2016) Structure of fenchone by broadband rotational spectroscopy. J Chem Phys 145(7):074311/1-074311/8 [http://dx.doi.org/10.1063/1.4961018]

3-Methyl-1-boratricyclo[3.3.1.13,7]decane 3-Methyl-1-boraadamantane C10H17B Cs

883 CAS RN: 1042687-92-2 MGD RN: 316921 GED augmented by QC computations

B

Bonds B–C(2) B–C(8) C(2)–C(3) C(8)–C(7) C(7)–C(6) C(7)–C(10) C(10)–C(3) C(3)–C(11) C–H b

re [Å] a 1.562(7) 1.553(4) 1.580(8) 1.576(6) 1.527(6) 1.538(10) 1.530(8) 1.524(13) 1.097(11)

Bond angles C(2)–B–C(8) C(8)–B–C(9) B–C(2)–C(3) B–C(8)–C(7) C(2)–C(3)–C(10) C(2)–C(3)–C(11) C(8)–C(7)–C(6)

θe [deg] a 116.3(2) 116.8(3) 100.0(8) 98.0(4) 108.7(6) 110.2(8) 110.0(3)

rg [Å] a 1.571(7) 1.562(4) 1.592(8) 1.588(6) 1.539(6) 1.549(10) 1.542(8) 1.537(13) 1.119(11)

CH3

10 Molecules with Ten or More Carbon Atoms

C(8)–C(7)–C(10) C(7)–C(6)–C(5) C(6)–C(7)–C(10) C(7)–C(10)–C(3) C(10)–C(3)–C(4) C(10)–C(3)–C(11)

791

110.3(4) 110.9(5) 109.4(4) 112.1(5) 108.7(6) 110.2(5)

Dihedral angles B–C(2)–C(3)–C(10) B–C(8)–C(7)–C(6) B–C(8)–C(7)–C(10) C(2)–B–C(8)–C(7) C(2)–C(3)–C(10)–C(7) C(8)–C(7)–C(6)–C(5) C(8)–C(7)–C(10)–C(3) C(7)–C(6)–C(5)–C(4)

τe [deg] a -59.1(6) -60.3(4) 60.4(2) -71.4(6) 61.5(7) 63.2(7) -63.2(4) 58.1(6)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit are estimated total errors. Average value.

The GED experiment was carried out at Tnozzle = 298 K. The molecule was assumed to have Cs point-group symmetry. Refined molecular parameters in Cartesian coordinates were flexibly restrained to the values from B3LYP/631G(d,p) calculation. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with quadratic and cubic force fields from computation at the level of theory as indicated above and taking into account nonlinear kinematic effects. Vishnevskiy YV, Abaev MA, Rykov AN, Gurskii ME, Belyakov PA, Erdyakov SY, Bubnov YN, Mitzel NW (2012) Structure and bonding nature of the strained Lewis acid 3-methyl-1-boraadamantane: A case study employing a new data-analysis procedure in gas electron diffraction. Chem Eur J 18 (34):10585-10594

Tricyclo[3.3.1.13,7]dec-1-ylphosphine 1-Adamantylphosphine C10H17P close to Cs

884 CAS RN: 23906-89-0 MGD RN: 387225 GED augmented by QC computations

PH2

Bonds P(1)–C(2) P–H C–C C–H C(2)–C(3) C(3)–C(6) C(6)–C(8)

rh1[Å] a 1.870(7) 1.424(10) 1.545(3) b 1.100(3) 1.545(3) c 1.546(4) c 1.543(4) c

Bond angles C(2)–P(1)–H H–P(1)–H C(2)–C(3)–C(6)

θh1 [deg] a 97.2(8) 93.7(10) 109.4(3)

792

10 Molecules with Ten or More Carbon Atoms

C(3)–C(6)–C(8) C(2)–C(3)–H C(3)–C(6)–H H–C(3)–H H–C(8)–H

110.6(4) 110.1(5) 109.9(5) 107.7(6) 107.4(6)

Dihedral angles torsion (PH2) d tilt (PH2) f

τh1 [deg] a 0.0 e 5.7(5)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Average value. c Differences between the listed C−C bond lengths were constrained to the values from MP2/aug-cc-pVTZ computation. d At 0°, a plane bisecting the PH2 group is coplanar with the symmetry plane passing through the C(2)C(3)C(6) plane. e Assumed at the value from computation as above. f Deviation of the P(1)–C(2) bond from the C(2)…X axis, where X is the center of the triangle formed by the C(3), C(4) and C(5) atoms; a positive value indicates the tilt away from the C(3) atom. b

The GED experiment was carried out at Tnozzle=361 K. Local C3v symmetry was assumed for the adamantyl cage. The phosphino group was found to be in a position almost bisecting a mirror plane of the adamantyl group. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/aug-cc-pVDZ computation. Wann DA, Turner AR, Goerlich JR, Kettle LJ, Schmutzler R, Rankin DWH (2011) Gas-phase structures of 1adamantylphosphines, PHn(1-Ad)3-n (n = 1-3). Struct Chem 22 (2):263-267

885 3-Chloro-2,4-bis(1,1-dimethylethyl)-1,3,5-triphosphatricyclo[2.1.0.02,5]pentane CAS RN: 131298-07-2 MGD RN: 384376 C10H18ClP3 GED augmented by Cs H 3C ab initio computations CH3 P

P

Bonds C–C C–H P–C P(1)–Cl C(3)–C(7) C(7)–C(methyl) P(1)–C(2) P(4)–C(2) C(3)–P(5) P(4)–P(5)

rh1[Å] a 1.5407(6) b 1.105(2) b 1.8693(7) b 2.166(15) 1.5335(28) c 1.5431(11) c 1.832(3) d 1.870(3) d 1.906(3) d 2.146(13) e

Bond angles C–C–H X…P(1)–Cl g C(2)–P(5)–C(3)

θh1 [deg] a

108.1(6) b,f 106.6(9) 72.9(2)

CH3 P

H 3C H 3C

Cl CH3

10 Molecules with Ten or More Carbon Atoms

X…C(7)–C(3) g C(8)–C(7)–C(9) C(8)–C(7)–C(6) C(3)–C(7)–C(8) C(3)–C(7)–C(6)

0.1(9) 109.6(9) f 108.8(9) f 108.5(3) h 109.8(4) h

Dihedral angles P(5)…X…C(2)–P(4) g P(1)…X…C(2)–P(5) g P(5)–C(3)–C(7)–C(8)

τh1 [deg] a

793

-90.5(7) -124.3(5) 174.6(23)

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Average value. c Difference between the C(3)−C(7) and C(7)−C(methyl) bond lengths was constrained to the value from MP2/6311+G* calculation. d Differences between the P−C bond lengths were constrained to the values from calculation as indicated above. e Dependent parameter. f Constrained to the value from calculation as indicated above. g X is the midpoint of the C(2)…C(3) vector. h Difference between the C(3)−C(7)−C(methyl) angles was constrained to the value from calculation as indicated above. b

The GED experiment was carried out at Tnozzle of 394 and 418 K at the long and short nozzle-to-film distances, respectively. Local Cs symmetry for each of the tert-butyl groups, with the C(3)–C(7)–C(9) angle being equal to the C(3)– C(7)–C(6) one, and overall Cs symmetry were assumed. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from MP2/6-311+G* computation. Wann DA, Masters SL, Robertson HE, Green M, Kilby RJ, Russell CA, Jones C, Rankin DWH (2011) Multiple bonding versus cage formation in organophosphorus compounds: The gas-phase structures of tricycloP3(CBut)2Cl and P≡C-But determined by electron diffraction and computational methods. Dalton Trans 40 (20):5611-5616

886 CAS RN: 41367-43-5 MGD RN: 214340 GED combined with MS and augmented by QC computations

Bis[µ-2,2-dimethylpropanato-O:O’]dicopper Copper(I) pivalate dimer C10H18Cu2O4 C2h (staggered) C2v (eclipsed) H 3C

Distances Cu(1)...Cu(2) Cu(1)…O(3) Cu(2)–O(5) C(7)–O(3) C(7)–O(5) C(7)–C(9) C(9)–C(11) C(9)–C(13) C–H

a,b

staggered 2.485(8) 1.868(4) 1.869(4) 1.263(3) 1.260(3) 1.528(4) 1.526(4) 1.534(4) 1.082(5) c

rh1[Å] eclipsed 2.484(9) 1.870(9) 1.868(4) 1.260(3) 1.263(3) 1.528(4) 1.526(4) 1.535(4) 1.081(5) c

O

Cu

O

O

Cu

O

CH3

H 3C H 3C

CH3 CH3

794

Bond angles Cu(2)…Cu(1)…O(3) Cu(1)…Cu(2)–O(5) C(10)–C(8)–O(4) C(8)–C(10)–C(12) C(8)–C(10)–C(14) Dihedral angle O(6)–C(8)–C(10)–C(14)

10 Molecules with Ten or More Carbon Atoms

θh1 [deg] b,d

staggered 86.2(2) 85.98(2) 119.4(22) 109.3(9) 108.2(16)

staggered 58.3(51)

eclipsed 86.1(2) 86.0(2) 118.7(27) 109.8(10) 107.2(20)

τh1 [deg] d

eclipsed 58.2(73)

Reproduced with permission of SNCSC.

staggered

eclipsed a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Differences between related parameters in each conformer were assumed at the values from the computation at the level of theory as indicated below. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. Two conformers, one with eclipsed and the other one with staggered conformation of the tert-butyl groups with respect to each other, were predicted by DFT computations. The eclipsed conformer is lower in energy than the staggered one by 0.05 kcal mol-1 only (B3LYP/ECP(Cu),cc-pVTZ(C,O,H)). The barrier to internal rotation of the tert-butyl group was estimated to be 0.2 kcal mol-1 (B3LYP/6-31G*), i.e. the tert-butyl groups are freely rotating at the temperature of the GED experiment (Teffusion cell = 413(5) K). Both conformers were considered in the GED analysis. However, their relative ratio could not be determined. Therefore, the final fitting to experimental intensities was done with application of two static models of a single conformer (staggered with C2h symmetry as well as eclipsed with C2v symmetry). The slightly better fit was obtained for the C2h molecular model.

10 Molecules with Ten or More Carbon Atoms

795

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated with harmonic force constants from B3LYP/ECP(Cu),cc-pVTZ(C,O,H) computation. Alikhanyan AS, Didenko KV, Girichev GV, Giricheva NI, Pimenov OA, Shlykov SA, Zhurko GA (2011) Gasphase structure and conformational properties of copper (I) pivalate dimer (CuC5H9O2)2. Struct Chem 22 (2):401-409

887 CAS RN: 470-82-6 MGD RN: 486737 MW supported by QC calculations

1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octane 1,8-Eucalyptol C10H18O Cs CH3

Bonds C(1)–C(2) C(1)–C(7) C(2)–C(3) C(3)–C(4) C(4)–C(8) C(8)–C(9)

rs [Å] a 1.527(62) 1.527(3) 1.550(33) 1.545(24) 1.530(5) 1.535(65)

Bond angles C(4)–C(3)–C(2) C(3)–C(2)–C(1) C(2)–C(1)–C(6) C(2)–C(1)–C(7) C(3)–C(4)–C(8) C(9)–C(8)–C(10)

θs [deg] a

O

CH3

H3C

108.6(5) 109.2(10) 110.8(3) 111.6(35) 109.7(26) 108.3(2)

Table 4 reprinted by permission of de Gruyter, Berlin. a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectrum of the title compound was recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8.5 GHz. Only one conformer was detected. No line splittings due to internal rotation were observed. The rs structure of the carbon skeleton was determined from the ground-state rotational constants of eight isotopic species (main and seven 13C). Medcraft C, Schnell M (2016) A comparative study of two bicyclic ethers, eucalyptol and 1,4-cineole, by broadband rotational spectroscopy. Z Phys Chem 230(1):1-14

888 CAS RN: MGD RN: 451319 MW

Distances

1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one – water (1/1) Camphor – water (1/1) C10H18O2 C1

low-energy r0 [Å] a

high-energy r0 [Å] a

796

10 Molecules with Ten or More Carbon Atoms

C(3)…O C(1)…O O…O O…H

3.242(4)

Angles O…O…C(3) O…O…C(1)

θ0 [deg] a

2.854(4)

46.98(6)

H 3C

3.474(7) 2.898(7) 2.482(7)

CH3

O H

θ0 [deg] a

H 3C

H

O

53.67(27)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

low-energy

high-energy

The rotational spectra of the binary complex of camphor with water were recorded in a supersonic jet by chirped-pulse FTMW spectrometers in the frequency region between 2 and 8 GHz. Two conformers were observed. The partial r0 structure of each conformer was determined from the ground-state rotational constants of two isotopic species (main and 18O) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Pérez C, Krin A, Steber AL, López JC, Kisiel Z, Schnell M (2016) Wetting camphor: multi-isotopic substitution identifies the complementary roles of hydrogen bonding and dispersive forces. J Phys Chem Lett 7(1):154-160

889 CAS RN: MGD RN: 451485 MW

1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one – water (1/2) Camphor – water (1/2) C10H20O3 C1 H 3C

Distances O(1)…O(2) O(2)…O(3) O(3)…H O(3)…C(3) Angle O(1)…O(2)…O(3)

low-energy r0 [Å] a 2.781(3) 2.821(2) 2.44(2)

high-energy r0 [Å] a 2.778(1) 2.837(1) 2.489(3) 3.375(2)

θ0 [deg] a

θ0 [deg] a

96.97(13)

82.17(3)

Reprinted with permission. Copyright 2015 American Chemical Society.

CH3

O H H 3C

O

H

2

10 Molecules with Ten or More Carbon Atoms a

797

Parenthesized uncertainties in units of the last significant digit.

high-energy

low-energy

The rotational spectra of the ternary complex of camphor with water were recorded in supersonic expansion by chirped-pulse FTMW spectrometers in the frequency region between 2 and 8 GHz. Two conformers were observed. The r0 structure of each conformer was determined from the ground-state rotational constants of four isotopic species (main, two 18O and 18O2) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Pérez C, Krin A, Steber AL, López JC, Kisiel Z, Schnell M (2016) Wetting camphor: multi-isotopic substitution identifies the complementary roles of hydrogen bonding and dispersive forces. J Phys Chem Lett 7(1):154-160

890 CAS RN: MGD RN: 485765 MW

1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one – water (1/3) Camphor – water (1/3) C10H22O4 CH3 H3C C1 O

Distances O(1)…H O(2)…H O(3)…H O(4)…H

r0 [Å] a 1.84(1) 1.81(1) 1.84(1) 2.594(16)

Angle O(1)…O(2)…O(3)

θ0 [deg] a

H H3C

H

3

O

82.17(3)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the quaternary complex of camphor with water were recorded in a supersonic jet by chirped-pulse FTMW spectrometers in the frequency region between 2 and 8 GHz. Only one conformer was observed.

798

10 Molecules with Ten or More Carbon Atoms

The r0 structure was determined from the ground-state rotational constants of eight isotopic species (main, three 18 O, three 18O2 and 18O3) under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. Pérez C, Krin A, Steber AL, López JC, Kisiel Z, Schnell M (2016) Wetting camphor: multi-isotopic substitution identifies the complementary roles of hydrogen bonding and dispersive forces. J Phys Chem Lett 7(1):154-160

891 CAS RN: 72190-67-1 MGD RN: 373915 GED augmented by ab initio computations

1,1',1''-(Silylmethylidyne)tris[1,1,1-trimethylsilane] [Tris(trimethylsilyl)methyl]silane C10H30Si4 essentially C3 H 3C

Bonds Si–H C–H Si(6)–C(1) d Si–C f

rh1 [Å] a 1.492(5) b 1.091(3) c 1.905(2) e 1.891(4) e

θh1 [deg] a

Dihedral angles Si(2)–C(1)–Si(6)–C(9) H(4)–C(9)–Si(6)–C(1) H(5)–C(10)–Si(6)–C(1) H(7)–C(11)–Si(6)–C(1) H(3)–Si(2)–C(1)–Si(6)

τh1 [deg] a

Si

CH3

H 3C H 3C

SiH3

Si

H3C Si H 3C

Bond angles C(1)–Si(6)–C C(1)–Si(6)–C(9) C(1)–Si(6)–C(10) C(1)–Si(6)–C(11) C(9)–Si(6)–C(10) C(9)–Si(6)–C(11) Si(2)–C(1)–Si C–Si–H Si–C–H

CH3

CH3

CH3

113.2(2) b 112.3 g 113.2 g 114.1 g 108.5(5) h 106.4(8) h 106.1(2) 111.4(5) h 112.0(4)

38.9(6) h -66.7(19) h 177.8(19) h 176.6(19) h 161.2(19) h

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Restrained to the value from MP2/6-31G(d) computation. c Average value d Si–C(1) distances in the C–Si(CH3)3 fragments. e Difference between the Si–C bond lengths was restrained to value from computation as indicated above. f All the other Si–C bond lengths except for those in the footnote d. g Difference between the C(1)–Si(6)–C angles were restrained to values from computation as indicated above. h Restrained to value from computation as indicated above. b

The GED experiment was carried out at the nozzle temperatures of 416 and 448 K at the long and short nozzleto-film distances, respectively. Local C3 symmetry was assumed for each of the CH3, SiH3 and C(Si(CH3)3)3 groups. Local C1 symmetry was assumed for each of the Si(CH3)3 groups.

10 Molecules with Ten or More Carbon Atoms

799

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from HF/6-31G(d) computation. Masters SL, Rankin DWH, Cordes DB, Bätz K, Lickiss PD, Boag NM, Redhouse AD, Whittaker SM (2010) The gas-phase structure and some reactions of the bulky primary silane (Me3Si)3CSiH3 and the solid-state structure of the bulky dialkyl disilane [(Me3Si)3CSiH2]2. Dalton Trans 39 (39):9353-9360

892 CAS RN: 58-27-5 MGD RN: 518346 GED augmented by QC computations

2-Methyl-1,4-naphthalenedione 2-Methyl-1,4-naphthoquinone C11H8O2 Cs

Bonds C(5)–C(10) C(5)–C(6) C(6)–C(7) C(7)–C(8) C(8)–C(9) C(9)–C(10) C(1)–C(9) C(1)–C(2) C(2)=C(3) C(3)–C(4) C(4)–C(10) C(1)=O(1) C(2)–C(12) C(4)=O(4)

re [Å] a 1.389(2) 1.384(2) 1.393(3) 1.384(2) 1.391(2) 1.400(3) 1.485(6) 1.492(6) 1.3419 b 1.471(6) 1.485(6) 1.215(4) 1.485(6) 1.216(4)

Bond angles C(9)–C(10)–C(5) C(10)–C(5)–C(6) C(5)–C(6)–C(7) C(6)–C(7)–C(8) C(7)–C(8)–C(9) C(8)–C(9)–C(10) C(9)–C(1)–C(2) C(1)–C(2)=C(3) C(2)=C(3)–C(4) C(3)–C(4)–C(10) C(4)–C(10)–C(9) C(10)–C(9)–C(1) C(9)–C(1)=O(1) C(2)–C(1)=O(1) C(1)–C(2)–C(12) C(3)=C(2)–C(12) C(3)–C(4)=O(4) C(10)–C(4)=O(4)

θe [deg] a

117.1(8) 123.3(8) 116.7(8) 123.3(8) 117.4(8) 122.3(8) 117.3(10) 120.8(6) 122.8(6) 118.3(10) 119.2(6) 121.6(6) 122.1(4) 120.5(4) 116.1(4) 123.1(4) 120.1(4) 121.6(4)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit were not specified, probably estimated total errors. b Assumed at the value from B3LYP/cc-pVTZ computation.

800

10 Molecules with Ten or More Carbon Atoms

The GED experiment was carried out at Tnozzle = 395(5) K. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with quadratic and cubic force constants from computation at the level of theory as indicated above by taking into account nonlinear kinematic effects. Khaikin LS, Tikhonov DS, Grikina OE, Rykov AN, Stepanov NF (2014) Quantum-chemical calculations and electron diffraction study of the equilibrium molecular structure of vitamin K3. Russ J Phys Chem A / Zh Fiz Khim 88 / 88 (5 / 5):886-889 / 895- 898

893 CAS RN: 60-80-2 MGD RN: 378900 MW augmented by ab initio calculations

1,2-Dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one Phenazone C11H12N2O C1 CH3

H 3C

Bonds N(1)–N(2) N(2)–C(3) C(3)=C(4) C(4)–C(5) C(5)–N(1) N(2)–C(6) C(3)–C(7) C(5)=O N(1)–C(1ꞌ) C(1ꞌ)–C(2ꞌ) C(2ꞌ)–C(3ꞌ) C(3ꞌ)–C(4ꞌ) C(4ꞌ)–C(5ꞌ) C(5ꞌ)–C(6ꞌ) C(6ꞌ)–C(1ꞌ)

r0 [Å] 1.405 a 1.394 a 1.362 a 1.457 a 1.423 a 1.469 a 1.494 a 1.223 a 1.417 a 1.404 a 1.399 a 1.400 a 1.401 a 1.398 a 1.402 a

Bond angles N(1)–N(2)–C(3) N(2)–C(3)=C(4) C(3)=C(4)–C(5) C(4)–C(5)–N(1) C(3)–N(2)–C(6) N(2)–C(3)–C(7) C(5)–N(1)–C(1ꞌ) N(1)–C(1ꞌ)–C(6ꞌ) C(1ꞌ)–C(6ꞌ)–C(5ꞌ) C(6ꞌ)–C(5ꞌ)–C(4ꞌ) C(5ꞌ)–C(4ꞌ)–C(3ꞌ) C(4ꞌ)–C(3ꞌ)–C(2ꞌ) C(3ꞌ)–C(2ꞌ)–C(1ꞌ)

θ0 [deg] b

Dihedral angles N(1)–N(2)–C(3)=C(4) N(2)–C(3)=C(4)–C(5) C(3)=C(4)–C(5)–N(1) C(6)–N(2)–C(3)–C(4) C(7)–C(3)–N(2)–N(1) O=C(5)–C(4)=C(3)

τ0 [deg] b

105.9 a 110.6 a 108.7 a 103.8 a 116.5 119.8 a 121.3 118.5 a 119.2 a 120.6 a 119.7 a 120.4 a 119.4 a

7.1 a –2.3 a –3.4 a 133.3 a –172.1 a 175.0 a

N N

O

10 Molecules with Ten or More Carbon Atoms

C(4)–C(5)–N(1)–C(1ꞌ) C(3)–N(2)–N(1)–C(1ꞌ) C(5)–N(1)–C(1ꞌ)–C(6ꞌ) N(1)–C(1ꞌ)–C(6ꞌ)–C(5ꞌ) C(1ꞌ)–C(6ꞌ)–C(5ꞌ)–C(4ꞌ) C(6ꞌ)–C(5ꞌ)–C(4ꞌ)–C(3ꞌ) C(5ꞌ)–C(4ꞌ)–C(3ꞌ)–C(2ꞌ) C(4ꞌ)–C(3ꞌ)–C(2ꞌ)–C(1ꞌ)

801

153.6 a -156.1 a 53.4 -179.5 a -1.8 a 1.1 a 0.3 a -0.9 a

Reproduced with permission of AIP Publishing.

a b

Constrained to the MP2/6-311++G(d,p) value. Uncertainties were not given in the original paper.

The rotational spectrum of phenazone was recorded in a supersonic jet by a Balle-Flygare type FTMW spectrometer in the frequency region between 4 and 18 GHz. One single conformer was observed for only one isotopic species. The partial r0 structure was obtained from three determined ground-state rotational constants. The remaining structural parameters were constrained to ab initio values (see above). Écija P, Cocinero EJ, Lesarri A, Fernández JA, Caminati W, Castaño F (2013) Rotational spectroscopy of antipyretics: conformation, structure, and internal dynamics of phenazone. J Chem Phys 138(11):114304/1114304/7 [http://dx.doi.org/10.1063/1.4794693]

894 CAS RN: 73-22-3 MGD RN: 210456 TRED combined with laser desorption and augmented by DFT computations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(1)–C(6) C(5)–C(6) C(6)–C(7) C(7)=C(8) C(1)–N(9) C(8)–N(9) C(7)–C(71) C(71)–C(72) C(72)–N(7) C(72)–C(73) C(73)=O(1) C(73)–O(2)

r [Å] a,b 1.419(2) 1.409(2) 1.430(2) 1.408(1) 1.440(1) 1.425(2) 1.464(3) 1.389(3) 1.402(2) 1.404(2) 1.530(1) 1.580(1) 1.487(1) 1.558(1) 1.244(2) 1.400(1)

Bond angles C(6)–C(1)–C(2) C(3)–C(2)–C(1) C(4)–C(3)–C(2) C(5)–C(4)–C(3) C(6)–C(5)–C(4)

θ [deg] a,b

122.25(71) 117.53(62) 121.18(91) 121.05(51) 119.08(59)

L-Tryptophan C11H12N2O2 C1 HN

NH2

O

OH

802

10 Molecules with Ten or More Carbon Atoms

C(5)–C(6)–C(1) C(8)=C(7)–C(6) N(9)–C(8)=C(7) C(8)–N(9)–C(1) C(72)–C(71)–C(7) N(7)–C(72)–C(71) C(73)–C(72)–C(71) C(73)–C(72)–N(7) O(1)=C(73)–C(72) ∆1 c ∆2 d ∆3 e ∆4 f

118.91(104) 106.54(89) 109.85(95) 109.27(127) 113.96(97) 110.05(100) 111.99(48) 111.10(22) 126.71(42) -9.66(28) 23.73(20) -26.44(10) -0.23(26)

Dihedral angles C(5)–C(4)–C(3)–C(2) C(5)–C(6)–C(1)–C(2) C(3)–C(2)–C(1)–C(6) C(3)–C(4)–C(5)–C(6) C(1)–C(6)–C(5)–C(4) C(1)–C(2)–C(3)–C(4) C(3)–C(2)–C(1)–N(9) C(7)–C(6)–C(5)–C(4) C(5)–C(6)–C(1)–N(9) C(7)–C(6)–C(1)–C(2) C(8)=C(7)–C(6)–C(1) N(9)–C(8)=C(7)–C(6) C(1)–N(9)–C(8)=C(7) C(8)–N(9)–C(1)–C(6) C(7)–C(6)–C(1)–N(9) C(8)=C(7)–C(6)–C(5) C(8)–N(9)–C(1)–C(2) C(71)–C(7)–C(6)–C(1) C(71)–C(7)–C(6)–C(5) N(9)–C(8)=C(7)–C(71)

τ [deg] a,b

-0.19(9) -0.25(27) 0.08(19) 0.01(11) 0.20(12) 0.14(16) 180.23(14) 179.73(7) 179.63(14) 180.10(16) -0.02(22) 0.06(17) -0.07(14) 0.06(27) -0.02(14) 180.40(24) 179.92(14) 181.16(42) 1.59(16) 178.87(19)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Type of structure was not specified. c Difference between the O(2)–C(73)–C(72) and O(2)–C(73)=O(1) angles. d Difference between the N(9)–C(1)–C(2) and N(9)–C(1)–C(6) angles. e Difference between the C(7)–C(6)–C(1) and C(7)–C(6)–C(5) angles. f Difference between the C(71)–C(7)–C(6) and C(71)–C(7)–C(8) angles. b

The laser desorbtion of the sample led to average vibrational temperature of 1000 K. The structural refinements were carried out by separating the “rigid” indol and “floppy” amino acid moieties, making the refinement of the “rigid” parameters unaffected by the small scattering contributions of the “floppy” fragment, at low scattering angles. The structural analysis was supported by results of B3LYP/6-311G(d,p) calculations predicted eleven conformers with structural parameters of indole fragment being identical within 0.0025 Å, 0.55° and 0.65° for bond lengths, bond angles and dihedral angles, respectively. Lee I-R, Gahlmann A, Zewail AH (2012) Structural dynamics of free amino acids in diffraction. Angew Chem Int Ed/Angew Chem 51/124(1/1):99-102/103-106

10 Molecules with Ten or More Carbon Atoms

895 CAS RN: 29442-43-1 MGD RN: 538935 GED combined with MS and augmented by QC computations

Bonds Si–Cl Si–C(2) C(2)–C(3) C(3)–C(4) Si–C(7) C(7)–C(12) C(12)–(11) C(10)–C(11) C(9)–C(10) C(9)–C(8) C(7)–C(8) C–H C(phenyl)–H Bond angles Si–C(2)–C3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–Si–C(6) C(2)–Si–Cl C(2)–Si–C(7) C(12)–C(7)–Si C(11)–C(12)–C(7) C(10)–C(11)–C(12) C(9)–C(10)–C(11) C(8)–C(9)–C(10) C(7)–C(8)–C(9) C(12)–C(7)–C(8) Dihedral angles Si–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(2)–Si–C(6)–C(5) Cl–Si–C(7)–C(12)

ra [Å] a,b eq axo 2.080(4) 2.075(4) 1.863(9) 1.862(9) 1.540(20) 1.542(20) 1.534(20) 1.534(20) 1.861(9) 1.864(9) 1.404(8) 1.406(8) 1.398(8) 1.395(8) 1.396(8) 1.398(8) 1.398(8) 1.396(8) 1.396(8) 1.398(8) 1.408(8) 1.404(8) 1.095(6) c 1.095(6) c c 1.084(6) 1.084(6) c

803

1-Chloro-1-phenylsilacyclohexane C11H15ClSi Cs (eq) C1 (axo) Si

Cl

eq

θh1 [deg] a,b

eq 110.8(8) 113.8(8) 114.4(8) 106.9 d 108.3(16) 112.8(22) 123.4(18) 121.0(6) 120.3(6) 120.1(6) 118.7 d 122.6 d 117.2 d

eq 53(2) -66.2 e 40.1 d 0.0 e

axo 109.3(8) 113.8(8) 114.5(8) 106.1 d 110.2(16) 110.0(22) 119.9(18) 121.3(6) 120.1(6) 120.1(6) 118.8 d 122.6 d 117.1 d

τh1 [deg] a

axo -56(2) 66.6 e -45.3 d 75.0 e

axo

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Small differences between similar parameters were constrained to the values from M06/aug-cc-pVTZ computations. c Average value. d Dependent parameter. e Adopted from calculation at the level of theory as indicated above. b

804

10 Molecules with Ten or More Carbon Atoms

Two conformers differing in the locations of the phenyl groups with respect to the silacyclohexane ring were predicted at the M06-2X and MP2 levels of theory (in conjunction with aug-cc-pVTZ basis set) and detected by GED (Tnozzle = 320(3) K). In one conformer (eq), the phenyl group is in equatorial position; in the other conformer (axo), this group has axial position and locates out of the ClSiC(7) plane. The predicted ratio of the conformers eq : axo = 71 : 29 (in %, M06-2X) agrees well with that determined by GED eq : axo = 79(15) : 21(15) (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X computation. Shainyan BA, Belyakov AV, Sigolaev YF, Khramov AN, Kleinpeter E (2017) Molecular structure and conformational analysis of 1-phenyl-1-X-1-silacyclohexanes (X = F, Cl) by electron diffraction, low-temperature NMR, and quantum chemical calculations. J Org Chem 82 (1):461-470

896 CAS RN: 2020341-49-3 MGD RN: 538740 GED combined with MS and augmented by QC computations

Bonds Si–F Si–C(2) C(2)–C(3) C(3)–C(4) Si–C(7) C(7)–C(12) C(12)–(11) C(10)–C(11) C(9)–C(10) C(9)–C(8) C(7)–C(8) C–H C(phenyl)–H Bond angles Si–C(2)–C3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–Si–C(6) C(2)–Si–F C(2)–Si–C(7) C(12)–C(7)–Si C(11)–C(12)–C(7) C(10)–C(11)–C(12) C(9)–C(10)–C(11) C(8)–C(9)–C(10) C(7)–C(8)–C(9) C(12)–C(7)–C(8) Dihedral angles Si–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5)

1-Fluoro-1-phenylsilacyclohexane C11H15FSi Cs (eq) C1 (axo) Cs (axi)

ra [Å] a,b eq axo 1.619(9) 1.614(9) 1.859(16) 1.859(16) 1.539(23) 1.540(28) 1.531(23) 1.531(28) 1.857(16) 1.864(16) 1.408(18) 1.410(18) 1.401(18) 1.399(18) 1.400(18) 1.401(18) 1.401(18) 1.399(18) 1.399(18) 1.401(18) 1.410(18) 1.404(18) 1.095(5) c 1.095(5) c c 1.085(5) 1.085(5) c

θh1 [deg] a,b

eq 111.2(31) 114.2(31) 114.9(31) 107.1 d 107.3(52) 114.5(40) 121.3 e 120.8(9) 120.0(9) 119.9(9) 120.0 d 120.9 d 118.4 d

eq 53(8) -66.2 e

axo 110.0(31) 114.2(31) 115.0(31) 105.8 d 108.8(52) 111.2(40) 120.0 e 121.2(9) 119.8(9) 119.9(9) 120.0 d 121.0 d 118.1 d

τh1 [deg] a

axo -55(8) 67(8)

Si F

eq

10 Molecules with Ten or More Carbon Atoms

C(2)–Si–C(6)–C(5) F–Si–C(7)–C(12)

35.8 d 0.0 e

805

-42.5 d 65(17)

Reprinted with permission. Copyright 2016 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. b Small differences between similar parameters were constrained to the values from M06-2X/aug-cc-pVTZ computations. c Average value. d Dependent parameter. e Adopted from calculation at the level of theory as indicated above. axo Three conformers differing in the locations of the phenyl groups with respect to the silacyclohexane ring were predicted at the M06-2X and MP2 levels of theory (in conjunction with aug-cc-pVTZ basis set) and detected by GED (Tnozzle = 310(4) K). In the main conformer, the phenyl ring is in equatorial position (eq); in the two other conformers, the axial phenyl group locates in or out of the FSiC(7) plane (these conformers are labelled as axi and axo, respectively). The ratio of the conformers was determined to be eq : axo : axi = 40(12) : 55(24) : 5. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X computations. Shainyan BA, Belyakov AV, Sigolaev YF, Khramov AN, Kleinpeter E (2017) Molecular structure and conformational analysis of 1-phenyl-1-X-1-silacyclohexanes (X = F, Cl) by electron diffraction, low-temperature NMR, and quantum chemical calculations. J Org Chem 82 (1):461-470

897 CAS RN: 4096-20-2 MGD RN: 540586 GED combined with MS and augmented by QC computations

1-Phenylpiperidine C11H15N C1 (equatorial) C1 (axial) N

Bonds N–C(1) N–C(5) N–C(6) C(1)–C(2) C(2)–C(3) C(6)–C(7) C(6)–C(11) C(7)–C(8) C(1)–Hʹ d C(1)–Hʹʹ e C(7)–H Bond angles N–C(1)–C(2) C(1)–C(2)–C(3) C(1)–N–C(5) C(1)–N–C(6)

rh1 [Å] a,b equatorial axial 1.478(6) 1.472(6) 1.468(6) 1.476(6) 1.420(3) c 1.410(3) 1.528(3) 1.536(3) 1.531(3) 1.536(3) 1.410(3) c 1.414(3) 1.407(3) 1.415(3) 1.395(3) 1.400(3) 1.111(2) 1.101(2) 1.095(2) 1.095(2) 1.089(2) 1.086(2)

θh1 [deg] b,f

equatorial 110.8(6) 110.6(6) 110.9(6) 113.5(5)

axial 112.6(6) 110.1(6) 108.9(6) 117.6(5)

equatorial

806

C(6)–C(7)–C(8) Ʃ(C–N–C) g Dihedral angles N–C(1)–C(2)–C(3) C(1)–C(2)–C(3)–C(4) C(7)–C(6)–N–C(1) φh

φi

10 Molecules with Ten or More Carbon Atoms

121.1(2) 340.4(16)

121.4(2) 343.7(16)

τh1 [deg] f

equatorial 57.2(30) -53.8(30) -60.1(4) 36(4) 11(3)

axial 57.0(30) b -52.2(30) b 33.0(16) 7(58) 89(3)

Copyright 2016 with permission from Elsevier.

axial

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters of the axial conformer were refined together with the corresponding parameters of the equatorial conformer by adding the differences from MP2/6-311G** computations. c Difference between the C(6)−C(7) and exocyclic C−N bond lengths was fixed to the value from computation as above. d Axial H atom. e Equatorial H atom. f Parenthesized uncertainties of the last digits are 3σ values. g Sum of the C–N–C angles. h Torsional angle between the plane through the N–C(phenyl) bond perpendicular to the benzene ring and the plane through the N–C(phenyl) bond and the direction of the electron lone pair on nitrogen. i Angle between the C(6)–N bond and the C(1)–C(2)...C(4)–C(5) plane. QC computations at the B3LYP, B3LYP-GD3, M06 and MP2 levels of theory in conjunction with 6-311G** basis set predicted the existence of two conformers with a chair conformation of the piperidine ring and differing in the locations of the phenyl group (equatorial or axial) rotating around its C2 axis. The GED experiment was carried out at Teffusion cell = 317(5) K. In the GED analysis, the ratio of the conformers was determined to be equatorial : axial = 90(10) : 10(10) (in %). This ratio corresponds to the free Gibbs energy difference of 1.38(51) kcal mol-1 and agrees well with theoretical predictions. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from MP2/6-311G** computation. Shlykov SA, Phien TD, Gao Y, Weber PM (2017) Structure and conformational behavior of N-phenylpiperidine studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 1132:3-10

898 CAS RN: 1643979-59-2 MGD RN: 466449 GED combined with MS and augmented by ab initio computations

Bonds Si(3)–C(13) Si(3)–C(4) Si(3)–C(2) O–C(2) O–C(6)

axial 1.876(4) 1.883(4) 1.897(4) 1.446(3) 1.425(3)

3-Methyl-3-phenyl-1-oxa-3-silacyclohexane 3-Methyl-3-phenyl-3-silatetrahydropyran C11H16OSi C1 (axial) C1 (equatorial)

rh1 [Å] a equatorial 1.873(4) 1.883(4) 1.897(4) 1.446(3) 1.425(3)

O

Si H 3C

10 Molecules with Ten or More Carbon Atoms

C(4)–C(5) C(5)–C(6) Si(3)–C(7) C(7)–C(8) C(8)–C(9) C–H b C–H d

1.540(5) 1.527(5) 1.876(4) 1.413(3) 1.401(3) 1.098(3) c 1.091(3) c

Bond angles C(2)–Si((3)–C(4) C(6)–C(5)–C(4) O–C(2)–Si(3) C(8)–C(7)–Si(3) C(6)–O–C(2) C(13)–Si(3)–C(7) Dihedral angles O–C(2)–Si(3)–C(4) C(6)–O–C(2)–Si(3) C(8)–C(7)–Si(3)–C(4) C(5)–C(6)–C(4)–O C(4)–C(5)–O–C(2) H(1)–C(13)–Si(3)–C(4) C(8)–C(7)–Si(3)–C(13) C(12)–C(7)–Si(3)–O

axial 99.9(19) 111.7 f 109.2(1) 120.9(2) 114.7(39) 112.1(14)

axial 48.5(44) -65.0(36) 76(8) -118.9(29) 1.8 f -171(18) -50(8) -21.1 f

807

1.540(5) 1.527(5) 1.876(4) 1.413(3) 1.401(3) 1.098(3) c 1.091(3) c

θh1 [deg] e

equatorial 99.8(19) 112.0 f 108.1(1) 120.1(2) 114.3(39) 111.5(14)

τh1 [deg] e

equatorial 49.7(44) -67.7(36) 46(44) -118.0(29) 3.4 f -171(18) 172(44) 122.3 f

Copyright 2015 with permission from Elsevier.

axial

equatorial

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b In the 1-oxa-3-silacyclohexane ring. c Average value. d In the phenyl ring. e Parenthesized uncertainties in units of the last significant digit are 3σ values. f Dependent parameter. The GED experiment was carried out at Tnozzle = 307(5) K. Two conformers differing in the orientation of the methyl group with respect to the 1-oxa-3-silacyclohexane ring (axial vs. equatorial) were found to be present in the ratio ax : eq = 62 : 38 (in %).

808

10 Molecules with Ten or More Carbon Atoms

Differences between the corresponding structural parameters of these conformers, except for the C(8)–C(7)– Si(3)–C(4) dihedral angles, and differences between homologous parameters in the equatorial conformer were assumed at the values from MP2/6-311G** computation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from computation at the level of theory as indicated above. Shainyan BA, Kirpichenko SV, Kleinpeter E, Shlykov SA, Osadchiy DY (2015) Molecular structure and conformational analysis of 3-methyl-3-phenyl-3-silatetrahydropyran. Gas-phase electron diffraction, low temperature NMR and quantum chemical calculations. Tetrahedron 71 (23):3810-3818

899 CAS RN: 85125-33-3 MGD RN: 418010 GED combined with MS and augmented by QC computations

Bonds Si–H Si–C(2) C(2)–C(3) C(3)–C(4) Si–C(7) C(7)–C(8) C(8)–C(9) Bond angles Si–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–Si–C(6) C(2)–Si–H C(2)–Si–C(7) Dihedral angles Si–C(2)–C(3)–C(4) C(2)–C(3)–C(4)–C(5) C(2)–Si–C(6)–C(5) H–Si–C(7)–C(8)

C11H16Si Cs (eq-orth) C1 (ax-twist)

rh1 [Å] a,b ax-twist eq-orth 1.485 d 1.488 d 1.880(4) 1.880(4) 1.544(3) 1.544(3) 1.539(3) 1.537(3) 1.882(4) 1.872(4) 1.408(3) 1.408(3) 1.398(3) 1.398(3)

θh1 [deg] b,c

ax-twist 109.6(3) 112.5(7) 112.4(7) 103.7(14) 111.9 d 110.2(15)

eq-orth

eq-orth 110.1(3) 114.5(7) 111.8(7) 103.0(14) 109.8 d 112.6(9)

τh1 [deg] b,c

ax-twist -60.4 e 67.2 e -45.8(19) 70(27)

Reproduced with permission of SNCSC.

a

1-Phenylsilacyclohexane

eq-orth 58.2 e -65.0 e 47.2(19) 9(6) ax-twist

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Differences between parameters of the conformers were assumed at the values from MP2/6-311G** computation. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Set equal to the value from computation at the level of theory indicated above. e Dependent parameter.

10 Molecules with Ten or More Carbon Atoms

809

Four conformers with the phenyl group in the axial or equatorial position relative to the silacyclohexane ring and/or with the different values of the H–Si–C(7)–C(8) angle were predicted by MP2 and B3LYP methods in conjunction with the 6-311G** and cc-pVTZ basis sets. The GED experiment was carried out at Teffusion cell = 293(5) K. The best fit to the GED data was obtained for the model comprising two conformers in which the phenyl groups possess the equatorial-orthogonal (i.e. in the symmetry plane of the silacyclohexane ring) and axial-twisted orientations. The ratio of the former conformer to the later was refined to be eq-orth : ax-twist = 62(10) : 38(10) (%) corresponding to the free energy difference of 0.29 kcal mol-1. A small amount (up to 10 %) of the axialorthogonal conformer could not be excluded. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from MP2/6-311G** computation. Shainyan BA, Kirpichenko SV, Osadchiy DY, Shlykov SA (2014) Molecular structure and conformations of 1phenyl-1-silacyclohexane from gas-phase electron diffraction and quantum chemical calculations. Struct Chem 25 (6):1677-1685

900 CAS RN: 23203-93-2 MGD RN: 144866 GED combined with MS and augmented by QC computations

(4Z)-5-Hydroxy-2,2,6,6-tetramethyl-4-hepten-3-one C11H20O2 C1 (see comment) O

OH

H 3C

CH3

a,b

Distances C(4)=C(5) C(4)–C(3) C(5)–C(6) C(3)–C(2) C(6)–C(9) C(6)–C(7) C(6)–C(8) C(2)–C(1) C(2)–C(10) C(2)–C(11) C(3)=O(2) C(5)–O(1) C(4)–H C(methyl)–H O(1)–Hʹ O(2)...Hʹ O(1)...O(2)

rh1 [Å] 1.369(3) 1 1.442(3) 1 1.520(3) 1 1.538(3) 1 1.533(3) 1 1.544(3) 1 1.544(3) 1 1.533(3) 1 1.542(3) 1 1.542(3) 1 1.249(3) 2 1.328(3) 2 1.076(3) 3 1.0913,c 1.009(3) 3 1.571(3) 2.519(3)

Bond angles C(5)=C(4)–C(3) C(4)=C(5)–O(1) C(4)–C(3)=O(2) C(6)–C(5)=C(4) C(2)–C(3)–C(4) C(5)–C(6)–C(9) C(5)–C(6)–C(7) C(3)–C(2)–C(1) C(3)–C(2)–C(10)

θh1 [deg] d

Dihedral angles C(6)–C(5)=C(4)…O(1) C(2)–C(3)–C(4)…O(2) C(9)–C(6)–C(5)–O(1)

τh1 [deg] d

121.6(7) 118.0(7) 123.4(9) 128.0(14) 118.3(25) 113.4(13) 107.3(19) 110.4(45) 111.9(18)

180 e 180 e 170(5)

H 3C

CH3

CH3

CH3

810

C(1)–C(2)–C(3)=O(2)

10 Molecules with Ten or More Carbon Atoms

30(4)

Copyright 2016 with permission from Elsevier [a].

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from B3LYP/aug-cc-pVTZ computations. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Enol ring was assumed to be planar. The molecular structure of dipivaloylmethane from Ref. [b] was reinvestigated. Only the enol tautomeric form was predicted by computations at the B3LYP and MP2 levels of theory (with up to aug-cc-pVTZ basis set) and detected by GED (Teffusion cell = 296(3) K). Two conformers, enol1 and enol2, differing in the orientations of the tert-butyl group adjacent to the double C=O bond (eclipsed and staggered, respectively), were predicted to exist in about equal amounts. Nevertheless, the GED data were described by the model of a single conformer. As a result, this tert-butyl group was determined to have an intermediate position (τ[C(1)–C(2)–C(3)=O(2)] = 30(4)°) between its orientations in enol1 (τ=0°) and enol2 (τ=60°) conformers predicted by computations. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. a. Belova NV, Trang NH, Oberhammer H, Girichev GV (2017) Tautomeric and conformational properties of dipivaloylmethane. J Mol Struct 1132:63-69 b. Giricheva NI, Girichev GV, Lapshina SB, Kuzmina NP (2000) Molecular structure of dipivaloylmethane and the intramolecular hydrogen bond problem. J Struct Chem (Eng. Transl.)/Zh. Strukt Khim 41/41(1/1):48-54/5866

901 CAS RN: 3319-01-5 MGD RN: 467599 GED combined with MS and augmented by QC computations

Bonds N–C(1) C(1)–C(2) N–C(6) C(6)–C(7) C(6)–C(11) C(7)–C(8) C(8)–C(9) C–H b C–H d Bond angles N–C(1)–C(2) C(1)–C(2)–C(3) C(1)–N–C(6) N–C(6)–C(7) C(6)–C(7)–C(8)

I 1.460(3) 1.535(3) 1.469(3) 1.544(3) 1.538(3) 1.540(3) 1.538(3) 1.106(3) c 1.110(3) c

1-Cyclohexylpiperidine C11H21N C1 (I) C1 (II)

rh1 [Å] a II 1.463(3) 1.536(3) 1.476(3) 1.543(3) 1.540(3) 1.538(3) 1.536(3) 1.105(3) c 1.112(3) c

θh1 [deg] e

I 108.5(10) 110.5(3) 112.9(18) 112.7(31) 110.8(3)

II 108.9(10) 111.5(3) 114.9(18) 105.9(31) 112.6(3)

N

10 Molecules with Ten or More Carbon Atoms

C(7)–C(6)–C(11) N–C(1)–Hʹ C(2)–C(1)–Hʹ Σ(C–N–C) f

110.4(3) 107.3(30) 110.4(4) 338.4(54)

811

109.0(3) 108.4(30) 108.6(4) 333.9(54)

τh1 [deg] e

Dihedral angles

I 59.1(19) 70.8(58) -170.8(43) -57.1(17) 56.2(17) 59(2) h 49(2) h 51(2) h 51(2) h

N–C(1)–C(2)–C(3) C(1)–N–C(6)–C(7) N–C(6)–C(7)–C(8) C(6)–C(7)–C(8)–C(9) C(7)–C(8)–C(9)–C(10) Flap1 g Flap2 i Flap3 j Flap4 k

II 59.4(19) -150(15) -174.3(43) -57.9(17) 54.6(17) 58(2) h 48(2) h 50(2) h 51(2) h

Reproduced with permission of SNCSC.

I

II

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Equatorial H atom. c Average value. d Axial H atom. e Parenthesized uncertainties in units of the last significant digit are 3σ values. f Sum of the C–N–C angles. g Acute angle between the C(1)–N–C(5) and C(1)–C(2)…C(4)–C(5) planes. h Dependent parameter. i Acute angle between the C(2)–C(3)–C(4) and C(1)–C(2)…C(4)–C(5) planes. j Acute angle between the C(7)–C(6)–C(11) and C(7)–C(8)…C(10)–C(11) planes. k Acute angle between the C(8)–C(9)–C(10) and C(7)–C(8)…C(10)–C(11) planes. QC computations at the B3LYP and MP2 levels of theory in conjunction with various basis sets predicted the existence of at least eight conformers, characterized by axial and/or equatorial positions of the rings with a chair shape and different orientation of the cycles with respect to each other (orthogonal or twisted). In the lowestenergy conformers, I and II, both cycles are in equatorial positions and oriented perpendicularly and nearly parallel to each other, respectively. The energy difference between these conformer was estimated to be 1.1 kcal mol-1 (MP2/6-311G**). The GED experiment was carried out at Tnozzle = 302 K. The sample molecules were found to be present at this temperature mainly as conformer I (74(13)%) and II (21(13)%). Structural differences between the conformers, except those for the C(7)–C(6)–N–C(1) dihedral angles, were adopted from MP2/6-311G** computation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using harmonic force constants from computation at the level as indicated above.

812

10 Molecules with Ten or More Carbon Atoms

Shlykov SA, Phien TD, Gao Y, Weber PM (2015) Molecular structure and conformational properties of Ncyclohexylpiperidine as studied by gas-phase electron diffraction, mass spectrometry, IR spectroscopy and quantum chemical calculations. Struct Chem 26 (5-6):1501-1512

902 CAS RN: 101017-15-6 MGD RN: 466093 GED augmented by QC computations

[Bis(bromodimethylsilyl)methylene]bis[trimethylsilane] C11H30Br2Si4 C1 (I, II) C2 (III, IV)

Bonds C(1)–Si(2) C(1)–Si(4) Si(2)–C(12) Si(2)–Br Si(4)–C(10) C–H

rh1 [Å] a 1.896(13) b 1.950(13) b 1.874(2) 2.277(2) 1.887(2) b 1.082(4) c

Bond angles C(1)–Si(2)–Br C(1)–Si(2)–C(12) C(1)–Si(4)–C(10) C(10)–Si(4)–C(11) C(12)–Si(2)–C(13) H–C–H C–Si–C(methyl) e C–Si–C(methyl) f C–Si–Br Si–C–Si

θh1 [deg] a,d

H 3C

I -158.7(12) -41.9(13)

Br–Si(2)–C(1)–Si(3) Br–Si(3)–C(1)–Si(2)

Si

CH3

H 3C

CH3

Br

Br

Si

Si

H 3C

CH3 Si H 3C

110.6(7) 116.3(7) 112.0(6) 106.0(7) 106.8(21) 108.1(4) 112.1(6) 116.2(7) 110.4(7) 110.0(2)

Dihedral angles

CH3

CH3

CH3

I

τh1 [deg] a,d

II -163.1(11) 75.7(11)

III -161.3(13)

IV 76.5(8)

Reprinted with permission. Copyright 2015 American Chemical Society.

II a b

III

IV

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Differences between the Si–C bond lengths were constrained to the values from MP2/aug-cc-pVDZ(PP) calculation.

10 Molecules with Ten or More Carbon Atoms

813

c

Constrained to the value from calculation at the level of theory as indicated above. Most of the refined angles were constrained to the values from calculation as indicated above. e Si(CH3)3 branch. f Si(CH3)2Br branch. d

B3LYP/aug-cc-pVDZ(PP) calculations predicted the existence of four conformers, I, II, III and IV, differing in the magnitudes of the Br–Si–C–Si torsional angles. The ratio of the conformers was estimated to be I : II : III : IV = 78.5 : 8.6 : 4.4 : 8.5 (in %, at 486 K). Conformers I and II have C1 point-group symmetry, whereas conformers III and IV were predicted to have C2 symmetry. The GED experiment was carried out at Tnozzle of 486 and 503 K for the long and short nozzle-to-film distances, respectively. Selected bond lengths and bond angles are presented for the predominant conformer (I). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from DFT calculation. Wann DA, Robinson MS, Bätz K, Masters SL, Avent AG, Lickiss PD (2015) Structures of tetrasilylmethane derivatives (XMe2Si)2C(SiMe3)2 (X = H, Cl, Br) in the gas phase, and their dynamic structures in solution. J Phys Chem A 119 (4):786-795

903 CAS RN: 60950-95-0 MGD RN: 465926 GED augmented by QC computations

[Bis(chlorodimethylsilyl)methylene]bis[trimethylsilane] C11H30Cl2Si4 C1 (I, II) C2 (III, IV) H3C

a,b

Bonds C(1)–Si(2) C(1)–Si(4) Si(2)–C(12) Si–Cl Si(4)–C(10) C–H

rh1 [Å] 1.901(3) b 1.938(3) b 1.877(7) b 2.083(2) 1.887(5) b 1.098(3) c

Bond angles C(1)–Si(2)–Cl C(1)–Si(2)–C(12) C(1)–Si(4)–C(10) C(10)–Si(4)–C(11) C(12)–Si(2)–C(13) H–C–H C–Si–C(methyl) e C–Si–C(methyl) f C–Si–Cl Si–C–Si

θh1 [deg] a,d

Dihedral angles Cl–Si(2)–C(1)–Si(3) Cl–Si(3)–C(1)–Si(2)

CH3

Si

CH3

H3C Cl

CH3

Si

Si

H3C

Cl CH3

Si H3C

CH3

CH3

109.6(6) 116.1(2) 111.9(3) 105.9(7) 107.9(13) 108.1(4) 111.8(3) 116.1(2) 109.6(6) 110.4(2)

I -156.7(9) -43.2(7)

I

II -160.8(5) 74.7(7)

τh1 [deg] a,d

III -161.5(6)

IV 76.9(4)

Reprinted with permission. Copyright 2015 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations.

814

10 Molecules with Ten or More Carbon Atoms

b

Differences between the Si–C bond lengths were constrained to the values from MP2/aug-cc-pVDZ computation. c Constrained to the value from computation as indicated above. d Most of the refined angles were constrained to the values from computation as indicated above. e Si(CH3)3 branch. f Si(CH3)2Cl branch.

II

III

IV

B3LYP/aug-cc-pVDZ calculations predicted the existence of four conformers, I, II, III and IV, differing in the magnitudes of the Cl–Si–C–Si torsional angles. The ratio of the conformers was estimated to be I : II : III : IV= 72.0 : 10.6 : 7.5 : 9.9 (in %, at 485 K). Conformers I and II have C1 point-group symmetry, whereas conformers III and IV were predicted to have C2 symmetry. The GED experiment was carried out at Tnozzle of 494 and 497 K for the long and short nozzle-to-film distances, respectively. Selected bond lengths and angles are presented for the predominant conformer (I). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from DFT calculation. Wann DA, Robinson MS, Bätz K, Masters SL, Avent AG, Lickiss PD (2015) Structures of tetrasilylmethane derivatives (XMe2Si)2C(SiMe3)2 (X = H, Cl, Br) in the gas phase, and their dynamic structures in solution. J Phys Chem A 119 (4):786-795

904 CAS RN: 101017-14-5 MGD RN: 465730 GED augmented by QC computations

Bonds C(1)–Si(2) C(1)–Si(4) Si(2)–C(12) Si–H Si(4)–C(10) C–H Bond angles C(1)–Si(2)–H(1) C(1)–Si(2)–C(12) C(1)–Si(4)–C(10) C(10)–Si(4)–C(11) C(12)–Si(2)–C(13)

[Bis(dimethylsilyl)methylene]bis[trimethylsilane] C11H32Si4 C1 (I, II, III) C2 (IV, V, VI)

rh1 [Å] a 1.901(6) b 1.910(6) b 1.887(1) b 1.533(21) 1.890(1) b 1.092(2) c

θh1 [deg] a,d 108.3(6) 115.2(9) 113.3(6) 107.0(7) 102.2(20)

H 3C

CH3 Si

CH3

H 3C

CH3 SiH

SiH

H 3C

CH3 Si H 3C

CH3

CH3

10 Molecules with Ten or More Carbon Atoms

H–C–H C–Si–C(methyl) e C–Si–C(methyl) f C(methyl)–Si–H Si–C–Si

815

107.8(4) 113.1(5) 115.2(8) 107.9(7) 108.6(4)

Dihedral angles H(1)–Si(2)–C(1)–Si(3) H(2)–Si(3)–C(1)–Si(2)

I -160.2(35) -41.2(15)

II -163.9(12) 79.3(30)

τh1 [deg] a,d

III 81.8(16) -43.3(13)

IV -161.5(7)

V 79.7(8)

VI -42.6(13)

Reprinted with permission. Copyright 2015 American Chemical Society.

I

IV

II

V

III

VI

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Differences between the Si–C bond lengths were constrained to the values from MP2/aug-cc-pVDZ computation. c Constrained to the value from computation as indicated above. d Most of the refined angles were constrained to the values from computation as indicated above. e Si(CH3)3 branch. f Si(CH3)2H branch. b

B3LYP/aug-cc-pVDZ calculations predicted the existence of six conformers, I-VI, differing in the magnitudes of the H–Si–C–Si torsional angles. The ratio of the conformers was estimated to be I : II : III : IV : V : VI : VII = 20.4 : 31.1 : 28.5 : 4.8 : 8.3 : 6.9 (in %, at 431 K). Conformers I, II and III have C1 point-group symmetry, whereas conformers IV, V and VI were predicted to have C2 symmetry. The GED experiment was carried out at Tnozzle of 426 and 460 K for the long and short nozzle-to-film distances, respectively. Selected bond lengths and bond angles are presented for the dominant conformer (II). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from DFT calculation.

816

10 Molecules with Ten or More Carbon Atoms

Wann DA, Robinson MS, Bätz K, Masters SL, Avent AG, Lickiss PD (2015) Structures of tetrasilylmethane derivatives (XMe2Si)2C(SiMe3)2 (X = H, Cl, Br) in the gas phase, and their dynamic structures in solution. J Phys Chem A 119 (4):786-795

905 CAS RN: 83-32-9 MGD RN: 208436 MW augmented by ab initio calculations

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(4)–C(7) C(7)–C(7)

r0 [Å] a 1.423(3) 1.414(2) 1.405(3) 1.380(3) 1.420(3) 1.380(4) 1.516(2) 1.563(4)

1,2-Dihydroacenaphthylene Acenaphthene C12H10 C2v

rs [Å] a 1.420(2)

1.381(6) 1.410(12) 1.386(3) 1.521(3) 1.560(5)

r (1) [Å] a m 1.423(2) 1.407(4) 1.408(3) 1.378(3) 1.416(3) 1.381(3) 1.515(2) 1.568(4)

Reprinted with permission. Copyright 2017 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of acenaphthene were recorded in a supersonic jet by chirped-pulse FTMW spectrometers in the frequency region between 2 and 8 GHz. The partial r0 structure was obtained from the ground-state rotational constants of seven isotopic species (main and six 13C); the remaining structural parameters were fixed at the values from MP2/aug-cc-pVDZ calculations. Steber AL, Pérez C, Temelso B, Shields GC, Rijs AM, Pate BH, Kisiel Z, Schnell M (2017) Capturing the elusive water trimer from the stepwise growth of water on the surface of the polycyclic aromatic hydrocarbon acenaphthene. J Phys Chem Lett 8(23):5744-5750

906 CAS RN: 75142-11-9 MGD RN: 517779 MW supported by ab initio calculations Distance O…C(3)

r (1) [Å] a m 3.280(8)

Angle O…C(3)–C(2)

θ (1) [deg] a m 91.2(5)

1,2-Dihydroacenaphthylene – water (1/1) Acenaphthene – water (1/1) C12H12O Cs

O H

H

10 Molecules with Ten or More Carbon Atoms

817

Reprinted with permission. Copyright 2017 American Chemical Society.

a

Parenthesized uncertainty in units of the last significant digit.

The rotational spectra of the binary complex of acenaphthene with water were recorded in a supersonic jet by chirped-pulse FTMW spectrometers in the frequency region between 2 and 8 GHz. was determined The partial mass-dependent structure r (1) m from the ground-state rotational constants of nine isotopic species (main, seven 13C and 18O). Steber AL, Pérez C, Temelso B, Shields GC, Rijs AM, Pate BH, Kisiel Z, Schnell M (2017) Capturing the elusive water trimer from the stepwise growth of water on the surface of the polycyclic aromatic hydrocarbon acenaphthene. J Phys Chem Lett 8(23):5744-5750

907 CAS RN: 17442-59-0 MGD RN: 129586 MW augmented by DFT calculations

Phenol dimer C12H12O2 C1 OH

Distances H…O O…O

r0 [Å] a 1.837(23) 2.833(21)

Angles O(7)–H(7)…O(8) C(9)–O(8)…H(7)

θ0 [deg] a

Dihedral angles O(8)…H(7)–O(7)–C(1) C(9)–O(8)…H(7)–O(7) C(10)–C(9)–O(8)…H(7) C(1)–O(7)…O(8)–C(9)

τ0 [deg] a

2

170.5(21) 122.5(10)

75.5(59) -27.7(47) 10.6(17) 64.0(13)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the phenol dimer were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8 GHz. All fourteen singly 13C- and 18O-substituted isotopic species were also investigated in natural abundance. The partial r0 structure was determined from the ground-state rotational constants with some constraints adopted from M06-2X/6-311++G(d,p) structure. Seifert NA, Steber AL, Neill JL, Pérez C, Zaleski DP, Pate BH, Lesarri A (2013) The interplay of hydrogen bonding and dispersion in phenol dimer and trimer: structures from broadband rotational spectroscopy. Phys Chem Chem Phys 15(27):11468-11477

818

10 Molecules with Ten or More Carbon Atoms

(η7-Cycloheptatrienylium)(η5-2,4-cyclopentadien-1-yl)titanium

908 CAS RN: 51203-49-7 MGD RN: 152055 MW augmented by QC calculations

Distances r1 b r2 c r3 d

r0 [Å] a 2.01(3) 1.48(3) 1.33(3)

Angle

θ0 [deg] a

δ

e

C12H12Ti Cs

Ti

8.0(2)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit. Distance between Ti and the center of cyclopentadienyl ring. c Distance between Ti and the center of cycloheptatrienylium ring. d Distance between Ti and the plane formed by the H atoms of the cycloheptatrienylium ring. e Drop angle of H atoms of the cycloheptatrienylium ring towards Ti. b

The rotational spectrum of the title compound was recorded by an FTMW spectrometer in the spectral region between 4 and 14 GHz. The partial r0 structure was determined from the ground-state rotational constants of four isotopic species (main (taken from the literature), two 13C and D); the C–C and C–H bond lengths were assumed at the values derived from several DFT and ab initio calculations. Daly AM, Lavin CM, Weidenschilling ES, Holden AM, Kukolich SG (2011) Microwave spectra, ab initio and DFT calculations and molecular structure for (η7-cycloheptatriene)Ti(η5-cyclopentadienyl) and (η7cycloheptatriene)Cr(η5-cyclopentadienyl). J Mol Spectrosc 267(1-2):172-177

909 CAS RN: 77472-70-9 MGD RN: 515960 GED augmented by DFT computations

Bonds N(1)–C(5) C(2)–C(3) C(3)–C(4) C(4)–C(5) N(1)–C(7) C(7)–C(8) C(4)–C(11) N(1)–C(2) C(8)–N(9)

2-Oxo-4-phenyl-1-pyrrolidineacetamide Carphedon C12H14N2O2 C1 (ax-) C1 (eq+)

rh1 [Å] a,b axeq+ 1.455(2) 1 1.455(2) 1 1 1.518(2) 1.519(2) 1 1 1.548(2) 1.541(2) 1 1 1.553(2) 1.547(2) 1 1 1.452(2) 1.453(2) 1 1 1.536(2) 1.536(2) 1 1 1.518(2) 1.514(2) 1 2 1.377(3) 1.375(3) 2 2 1.373(3) 1.371(3) 2

10 Molecules with Ten or More Carbon Atoms

C(2)=O(6) C(8)=O(10) O(6)...H(1) Bond angles C(2)–N(1)–C(5) N(1)–C(2)–C(3) N(1)–C(2)=O(6) C(7)–C(8)=O(10) C(2)–N(1)–C(7) N(1)–C(7)–C(8) C(7)–C(8)–N(9) C(3)–C(4)–C(11) ΣN(1) d Dihedral angles C(3)–C(2)–N(1)–C(5) C(2)–C(3)…C(5)–C(4) C(5)–N(1)–C(2)=O(6) C(3)–C(2)–N(1)–C(7) C(2)–N(1)–C(7)–C(8) N(1)–C(7)–C(8)–N(9) N(1)–C(7)–C(8)=O(10) C(2)–C(3)–C(4)–C(11) C(4)–C(11)–C(12)–C(13) C(3)–C(4)–C(11)–C(12)

1.234(2) 3 1.227(2) 3 2.09(3)

819

1.234(2) 3 1.227(2) 3 2.07(3)

θh1 [deg] a,b

ax113.0(6) 4 107.3(6) 4 122.4(17) 5 119.7(17) 5 121.9(19) 112.0(19) 115.3(13) 113.1 c 358.6(16)

ax8.1 c 161.8 c -170.6 c 175.0 c -78.7 c 76.4 c -103.5 c 105.5 c 180.8 c 114.0 c

Reproduced with permission of SNCSC.

eq+ 113.1(6) 4 107.0(6) 4 122.4(17) 5 119.7(17) 5 122.4(19) 112.2(19) 115.3(13) 116.6 c 359.6(15)

ax-

τe [deg]

eq+ 0.4 c -152.1 c -180.1 c -172.8 c -83.6 c 71.9 c -108.7 c 153.3 c 179.8 c 122.0 c eq+

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/cc-pVDZ calculation. c Assumed as above. d Sum of the angles at the N(1) atom. b

The GED experiment was carried out at Tnozzle= 439 K. The best fit to the experimental data was obtained for the equimolar mixture (50(11) %) of axial (ax-) and equatorial (eq+) conformers differing in the locations of the phenyl groups. The C(4) atom and the acetamide group locate on the same (eq+) or different (ax-) sides relative to the N(1)C(2)C(3)C(5) plane. Each conformer is stabilized by the O(6)...H(1) intramolecular hydrogen bond. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVDZ computation. Ksenafontov DN, Moiseeva NF, Rykov AN, Shishkov IF, Oberhammer H (2013) Molecular structure of carphedon as studied by gas electron diffraction and quantum chemical calculations. Struct Chem 24 (1):171-179

910 CAS RN: MGD RN: 551251 MW supported by ab initio calculations

1,2-Dihydroacenaphthylene – water (1/2) Acenaphthene – water (1/2) C12H14O2 Cs

820

Distances O(1)…C(3) O(1)…O(2)

10 Molecules with Ten or More Carbon Atoms

r (1) [Å] a m 3.250(9) 2.964(26)

rs [Å] a

3.003(5)

O H

H

2

θ (1) [deg] a m

Angles O(1)…C(3)-C(2) O(2)…O(1)…C(3)

78.4(3) 77.7(4)

Reprinted with permission. Copyright 2017 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the ternary complex of acenaphthene with water were recorded in a supersonic jet by chirped-pulse FTMW spectrometers in the frequency region between 2 and 8 GHz. structures were determined from the The partial rs and r (1) m ground-state rotational constants of three isotopic species (main and two 18O). Steber AL, Pérez C, Temelso B, Shields GC, Rijs AM, Pate BH, Kisiel Z, Schnell M (2017) Capturing the elusive water trimer from the stepwise growth of water on the surface of the polycyclic aromatic hydrocarbon acenaphthene. J Phys Chem Lett 8(23):5744-5750

911 CAS RN: 19464-95-0 MGD RN: 211000 MW supported by QC calculations

(2R,3R)-rel-3-Methyl-3-phenyl-2-oxiranecarboxylic acid ethyl ester cis-α,β-Epoxy-β-methylhydrocinnamic acid ethyl ester C12H14O3 Cs H3C

O

O a

Bonds C(7)–C(8) C(7)–C(9) O(1)–C(9) C(9)–C(10) O(2)=C(10) O(3)–C(10) C(11)–O(3) C(11)–C(12)

rs [Å] 1.506(16) 1.477(19) 1.43(16) 1.49(6) 1.20(13) 1.40(9) 1.41(7) 1.53(5)

Bond angles C(8)–C(7)–C(4) C(9)–C(7)–C(4) O(1)–C(9)–C(7) O(2)=C(10)–C(9) C(11)–O(3)–C(10) C(12)–C(11)–O(3)

θs [deg] a

Dihedral angles C(8)–C(7)–C(4)–C(5) C(9)–C(7)–C(4)–C(5)

τs [deg] a

117.3(15) 119(5) 59(4) 122(7) 115(5) 110(4)

-113.5(24) 93(4)

O

CH3

10 Molecules with Ten or More Carbon Atoms

C(10)–C(9)–C(7)–C(4) O(2)=C(10)–C(9)–C(7) O(3)–C(10)–C(9)–C(7) C(11)–O(3)–C(10)–C(9) C(12)–C(11)–O(3)–C(10)

821

5(7) 113(10) -65(5) 173(5) -83(7)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the diastereomeric mixture of strawberry aldehyde were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The partial rs structure of the most stable conformer, characterized by the synperiplanar O(1)–C(9)–C(10)–O(3) and synclinal‒ C(10)– O(3)–C(11)–C(12) dihedral angles, was determined from the ground-state rotational constants of thirteen isotopic species (main and twelve 13C) studied in natural abundance. Shipman ST, Neill JL, Suenram RD, Muckle MT, Pate BH (2011) Structure determination of strawberry aldehyde by broadband microwave spectroscopy: Conformational stabilization by dispersive interactions. J Phys Chem Lett 2(5):443-448.

912 CAS RN: 19464-92-7 MGD RN: 305433 MW augmented by QC calculations

(2R,3S)-rel-3-Methyl-3-phenyl-2-oxiranecarboxylic acid ethyl ester trans-α,β-Epoxy-β-methylhydrocinnamic acid ethyl ester C12H14O3 Cs H 3C

O

O a

Bonds C(7)–C(9) C(7)–O(1)

rs [Å] 1.46(4) 1.46(4)

Bond angles C(8)–C(7)–C(4) C(9)–C(7)–C(4) C(10)–C(9)–C(7) O(3)–C(10)–C(9) C(11)–O(3)–C(10)

θs [deg] a

Dihedral angles C(8)–C(7)–C(4)–C(3) C(10)–C(9)–C(7)–C(4) O(3)–C(10)–C(9)–C(7) C(11)–O(3)–C(10)–C(9) C(12)–C(1)–O(3)–C(10)

θs [deg] a

O

118.2(24) 119.9(23) 123.2(23) 109.9(18) 113.8(18)

144.3(12) -150.3(17) 124(3) -179(7) 173.9(26)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the diastereomeric mixture of strawberry aldehyde were recorded

CH3

822

10 Molecules with Ten or More Carbon Atoms

in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 6.5 and 18.5 GHz. The partial rs structure of the most stable conformer, characterized by the synperiplanar O(1)–C(9)–C(10)–O(3) and synclinal‒ C(10)–O(3)–C(11)–C(12) dihedral angles, was determined from the ground-state rotational constants of thirteen isotopic species (main and twelve 13C) studied in natural abundance. Shipman ST, Neill JL, Suenram RD, Muckle MT, Pate BH (2011) Structure determination of strawberry aldehyde by broadband microwave spectroscopy: Conformational stabilization by dispersive interactions. J Phys Chem Lett 2(5):443-448.

913 CAS RN: MGD RN: 528991 MW supported by ab initio calculations

1,2-Dihydroacenaphthylene – water (1/3) Acenaphthene – water (1/3) C12H16O3 C1 O a

Distances O(1)…O(2) O(2)…O(3) O(1)...O(3)

r0 [Å] 2.856(10) 2.825(14) 2.944(10)

Angles O(3)…C(3)–C(2) O(1)…O(3)…C(3) O(2)…O(1)…O(3)

θ0 [deg] a

H

a

rs [Å] 2.851(3) 2.808(12) 2.930(12)

H

3

119.97(27) 64.25(20) 58.28(31)

Reprinted with permission. Copyright 2017 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the quaternary complex of acenaphthene with water were recorded in a supersonic jet by chirped-pulse FTMW spectrometers in the frequency region between 2 and 8 GHz. The partial r0 and rs structures were determined from the ground-state rotational constants of four isotopic species (main and three 18O). Steber AL, Pérez C, Temelso B, Shields GC, Rijs AM, Pate BH, Kisiel Z, Schnell M (2017) Capturing the elusive water trimer from the stepwise growth of water on the surface of the polycyclic aromatic hydrocarbon acenaphthene. J Phys Chem Lett 8(23):5744-5750

[4,4'-[1,2-Ethanediyldi(nitrilo-κN)]bis[2-pentanato-κO]]zinc 914 CAS RN: 96114-86-2 N,N'-Ethylenebis(acetylacetonato)zinc(II) MGD RN: 356433 C12H18N2O2Zn GED combined with MS and augmented H 3C CH3 C2 by DFT computations N

N

Distances C(1)–C(2) C(5)–C(20) C(5)–C(6) C(6)–C(7) C(7)–C(28)

rh1 [Å] a,b 1.559(5) 1 1.523 1 1.429 1 1.403 1 1.519 1

Zn O

H 3C

O CH3

10 Molecules with Ten or More Carbon Atoms

C(1)–N(3) N(3)–C(5) C–N C(1)–H(1) C(20)–H(3) C(6)–H(2) C(28)–H(4) C–H O(8)–C(7) Zn–N(3) O(8)–Zn N(3)...N(4) O(8)...O(12) N(3)...O(8)

1.474(8) 2 1.335 2 1.405(8) c 1.147 3 1.142 3 1.134 3 1.142 3 1.141(4) c 1.295(7) 2.012(16) 1.958(13) d 2.606(20) d 3.269(62) d 2.827(17) d

Bond angles O(8)–Zn–O(12) N(3)–Zn–O(8) N(3)–Zn–N(4) C(1)–C(2)–N(4) C(1)–N(3)–C(5) N(3)–C(5)–C(6) C(5)–C(6)–C(7) O(8)–C(7)–C(6) H(1)–C(1)–C(2) H(3)–C(20)–C(5) H(4)–C(28)–C(7)

θh1 [deg] e

Dihedral angles N(3)–C(1)–C(2)–N(4) C(5)–N(3)–C(1)–C(2) C(6)–C(5)–N(3)–C(1) C(7)–C(6)–C(5)–N(3) O(8)–C(7)–C(6)–C(5) O(8)…N(3)…O(12)…N(4) H(3)–C(20)–C(5)–C(6) H(4)–C(28)–C(7)–C(6)

823

113.2(28) d 90.8(8) d 80.7(10) d 106.1(10) 118.4(10) 119.6(9) 124.2(10) 129.6(7) 109.0 f 110.8 f 112.9 f

τh1 [deg] e

-44.3(32) -151.2(51) 173.8(36) -10.6(51) 12.9(55) 123.4(48) d 51(32) -37(66)

Reproduced with permission of SNCSC. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscript were refined in one group; differences between parameters in each group were adopted from B3LYP/6-31G* computation. c Average value. d Dependent parameter. e Parenthesized uncertainties in units of the last significant digit are 3σ values. f Assumed at the value from computation as indicated above. The GED experiment was carried out at Tnozzle of 503(5) K. Local C3v symmetry was assumed for each of the methyl groups. Bond angle configurations around the C(5) and C(7) atoms were assumed to be planar. The central ZnC2N2 unit was found to be nonplanar. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-31G* computation.

824

10 Molecules with Ten or More Carbon Atoms

Girichev GV, Giricheva NI, Pelevina ED, Tverdova NV, Kuz'mina NP, Kotova OV (2010) Structure of a zinc(II) N,N'-ethylene-bis(acetylacetoniminate) molecule, ZnO2N2C12H18, according to gas electron diffraction data and quantum chemical calculations. J Struct Chem (Engl Transl)/Zh Strukt Khim 51/51 (1/1):23-31/29-37

915 CAS RN: 856297-46-6 MGD RN: 210376 MW supported by DFT calculations

2,6-Bis(1-methylethyl)phenol 2,6-Diisopropylphenol C12H18O C1 CH3

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(1) C(2)–C(7) C(7)–C(8) C(7)–C(9) C(6)–C(10) C(10)–C(11) C(10)–C(12)

r0 [Å] a

1.502(10) 1.545(26) 1.516(39) 1.498(10) 1.541(8) 1.522(11)

rs [Å] a 1.383(23) 1.413(16) 1.401(15) 1.380(14) 1.430(15) 1.383(23) 1.511(10) 1.506(10) 1.535(8) 1.543(10) 1.535(8) 1.537(11)

Bond angles C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(4)–C(5)–C(6) C(1)–C(2)–C(7) C(2)–C(7)–C(8) C(2)–C(7)–C(9) C(1)–C(6)–C(10) C(6)–C(10)–C(11) C(6)–C(10)–C(12)

θ0 [deg] a

θs [deg] a

120.9(9) 114.1(17) 112.1(12) 120.5(9) 114.2(17) 111.1(13)

114.7(9) 110.4(11)

Dihedral angles C(1)–C(2)–C(7)–C(8) C(1)–C(2)–C(7)–C(9) C(1)–C(6)–C(10)–C(11) C(1)–C(6)–C(10)–C(12)

θ0 [deg] a

-155.4(32) 75.3(14) 154.4(36) -76.8(15)

H 3C

OH

CH3

CH3

118.0(14) 120.4(7) 120.0(7) 120.6(7) 121.4(17) 114.8(8) 110.3(10)

θs [deg] a

-158.2(26) 77.0(30) 157.3(26) -80.0(13)

Reprinted with permission. Copyright 2010 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are 1σ values.

The rotational spectra of 2,6-diisopropylphenol (also known as propofol) were recorded in a supersonic jet by chirped-pulse FTMW spectrometers in the frequency region between 7 and 18.5 GHz. Three conformers were observed.

10 Molecules with Ten or More Carbon Atoms

825

The partial r0 and rs structures of the carbon skeleton were determined from the ground-state rotational constants of thirteen isotopic species (main and twelve 13C). A plane-symmetric gauche orientation of the two methine H atoms in the isopropyl groups was revealed. Lesarri A, Shipman ST, Neill JL, Brown GG, Suenram RD, Kang L, Caminati W, Pate BH (2010) Interplay of phenol and isopropyl isomerism in propofol from broadband chirped-pulse microwave spectroscopy. J Amer Chem Soc 132(38):13417-13424

916 CAS RN: 55909-52-9 MGD RN: 540193 GED combined with MS and augmented by QC computations

Bonds Si–C(1) Si–C(6) Si–C(7) C(1)–C(2) C(2)–C(3) C(7)–C(8) C(1)–H b C(1)–H d Bond angles C(1)–Si–C(5) Si–C(1)–C(2) C(1)–C(2)–C(3) C(1)–Si–C(6) C(1)–Si–C(7) Si–C(7)–C(8) C(7)–C(8)–C(9) Dihedral angles Si–C(1)–C(2)–C(3) C(1)–C(2)–C(3)–C(4) φf Flap1 g Flap2 i

1-Methyl-1-phenylsilacyclohexane C12H18Si C1 (ax-twist) Cs (eq-orth)

rh1 [Å] a eq-orth 1.883(4) 1.879(4) 1.880(4) 1.544(4) 1.538(4) 1.414(3) 1.100(3) c 1.103(3) c

ax-twist 1.882(4) 1.876(4) 1.886(4) 1.544(4) 1.538(4) 1.414(3) 1.100(3) c 1.103(3) c

Si H3C

θh1 [deg] e

ax-twist 103.5(5) 110.4(3) 113.4(4) 112.6(5) 109.0(5) 123.7(16) 121.5(1)

ax-twist 56.7(13) -65.5(15) 3.7(14) 44(2) h 57(2) h

eq-orth 103.3(5) 111.1(3) 113.5(4) 110.9(5) 111.7(5) 123.6(16) 121.4(1)

τh1 [deg] e

eq-orth 56.7(15) -65.2(15) 86.9(60) 42(2) h 57(2) h

Copyright 2017 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Equatorial H atom. c Average value. d Axial H atom. e Parenthesized uncertainties in units of the last significant digit are 3σ values. f Torsional angle of the phenyl ring defined as φ = [C(methyl)–Si–C(7)–C(8)] – 90°. g Angle between the C(1)–Si–C(5) and C(1)–C(2)...C(4)–C(5) planes.

eq-orth

826 h i

10 Molecules with Ten or More Carbon Atoms

Dependent parameter. Angle between the C(2)–C(3)–C(4) and C(1)–C(2)...C(4)–C(5) planes.

ax-twist Four conformers differing by locations of the phenyl group with respect to the silacyclohexane ring ring (axial vs. equatorial) and to the Si–C(phenyl) rotational axis (orthogonal vs. twisted) were predicted by QC computations. Two of these conformers, eq-orth and ax-twist, were found to be dominant in the gas phase by GED at Teffusion cell = 301(3) K. Small amount of the eq-twist conformer was also detected. The summarized mole fractions of the axial and equatorial conformers were determined to be ax : eq = 58(15) : 42(15) (in%). This ratio corresponds to free nergy difference ∆G = Geq – Gax = 0.19(37) kcal mol-1. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from M06-2X/6-311G** computation. Small differences between similar parameters were fixed at the values from computations at the level of theory as indicated above. Phien TD, Shlykov SA, Shainyan BA (2017) Molecular structure and conformational behavior of 1-methyl-1phenylsilacyclohexane studied by gas electron diffraction, IR spectroscopy and quantum chemical calculations. Tetrahedron 73 (8):1127-1134

917 CAS RN: 1801851-97-7 MGD RN: 467225 GED augmented by QC computations

(1α,3α,5α)-1,3,5-Triethynyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane C12H18Si3 C3v (eq-eq-eq) H

H C

C

CH3

C

C

Si

Bonds Si–C(2) Si–C(9) Si–C(7) C(7)≡C(8)

re [Å] a 1.860(5) b 1.885(5) b 1.843(5) b 1.204(3)

Bond angles Si–C–Si C(2)–Si–C(6) C(9)–Si–C(7) C(2)–Si–C(7) C(9)–Si–C(2)

θe [deg] a

Dihedral angle Si–C–Si–C

τe [deg] a

rg [Å] a 1.871(5) 1.899(5) 1.854(5) 1.211(3)

CH3 Si

H 3C

117.2(9) 106.4(18) 108.8(28) 109.0(10) 111.8(16)

54.0(32)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Si

Parenthesized uncertainties in units of the last significant digit are probably 3σ values.

C C H

10 Molecules with Ten or More Carbon Atoms b

827

Differences between the Si–C bond lengths were assumed at the values from B3LYP/6-31G(d,p) calculation.

The GED experiment was carried out at the nozzle temperatures of 381 and 388 K at the short and long nozzle-to-detector distances. Two conformers, eq-eq-eq and ax-ax-ax, with all ethynyl groups in equatorial and axial positions, respectively, were considered in the GED model. The C3v point-group symmetry was assumed for each of the conformers. The amount of the eq-eq-eq conformer was determined to be 99(15)%. This result is in agreement with prediction of PBE0/6-31G(d,p) calculation (88%) and very far from that of MP2/cc-pVTZ one (41 %). Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with quadratic and cubic force constants from QC computation by taking into account non-linear kinematic effects Weisheim E, Reuter CG, Heinrichs P, Vishnevskiy YV, Mix A, Neumann B, Stammler HG, Mitzel NW (2015) Tridentate Lewis acids based on 1,3,5-trisilacyclohexane backbones and an example of their host-guest chemistry. Chem Eur J 21 (35):12436-12448 918 CAS RN: 95076-09-8 MGD RN: 381823 GED augmented by QC computations

Bis[µ-(2-methyl-2-propanolato)]tetramethyldigallium C12H30Ga2O2 C2h H 3C H 3C

Bonds Ga–O Ga–C C–O C(2)–C(3) C(2)–C(4) C–H

rh1 [Å] a 1.979(2) b 1.965(3) b 1.441(5) c 1.539(3) c 1.537(4) c 1.104(3) d,e

Bond angles Ga–O–Ga O–Ga–O O–C(2)–C(3) O–C(2)–C(4) C–Ga–C C(3)–C(2)–C(4) O…O–C C–C–H Ga–C–H H–C–H

θh1 [deg] a

Dihedral angles C–Ga…Ga–O H–C–Ga…Ga

τh1 [deg] a

CH3 CH3

Ga O

H 3C H 3C

O

CH3 CH3

Ga

H 3C

CH3

98.5(2) 81.5(3) d 108.0(5) f 110.2(7) f 122.2(16) d 108.2(8) d,g 168.4(17) d,g 110.5(9) d,e,g 112.0(8) d,e,g 108.2(10) d,e,g

89.6(31) d 5.4(21) d,g

Reprinted with permission. Copyright 2012 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Differences between the Ga–O and Ga–C bond lengths were restrained to the values from MP2_full/6-311+G* calculation. c Differences between the C–O and C–C bond lengths were restrained to the values from computation as indicated above. d Independent parameter. e Average value. b

828

10 Molecules with Ten or More Carbon Atoms

f

Differences between the O–C(2)–C bond angles were restrained to the values from computation as indicated above. g Restrained to the value from computation as indicated above. Only dimeric molecules of dimethylalkoxygallane were observed in the gas phase at the temperature of the GED experiment (Tnozzle = 373…393 K). The title molecule was assumed to have C2h point-group symmetry. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-311+G* calculation. Knapp CE, Wann DA, Bil A, Schirlin JT, Robertson HE, McMillan PF, Rankin DWH, Carmalt CJ (2012) Dimethylalkoxygallanes: Monomeric versus dimeric gas-phase structures. Inorg Chem 51 (5):3324-3331

919 CAS RN: 197305-30-9 MGD RN: 517976 GED augmented by DFT computations

1,1,1,4,4,4-Hexamethyl-2,3-bis(trimethylsilyl)tetrasilane C12H38Si6 C2 (I) C2 (II) C2 (III)

Si(1)–Si(2) Si(1)–Si(5) Si(1)–Si(6) Si(1)–H(1)

rh1 [Å] a,b I II 2.374(1) 2.376(1) 2.364(1) 2.361(1) 2.366(1) 2.363(1) 1.502(16) 1.501(16)

Bond angles

θh1 [deg] a,b

Bonds

Si(5)–Si(1)–Si(6) Si(2)–Si(1)–Si(5) Si(2)–Si(1)–Si(6) Si(2)–Si(1)–H(1) H(1)–Si(1)–Si(5) H(1)–Si(1)–Si(6) Si(1)–Si(5)–C(31) Si(1)–Si(6)–C(51) Dihedral angle H(2)–Si(2)–Si(1)–H(1)

I 113.5(7) 117.1(4) 110.6(7) 106.0(6) 103.9(10) 104.3(10) 112.4(4) 110.2(4)

II 111.9(7) 107.4(4) 121.1(7) 106.0(6) 105.8(10) 103.4(10) 108.8(4) 110.6(4)

III 2.374(1) 2.364(1) 2.372(1) 1.501(16)

III 111.6(7) 112.3(4) 118.1(7) 105.0(6) 105.0(10) 103.3(10) 109.5(4) 112.3(4)

τh1 [deg] a

I 87.7(17)

II III -102.0(44) -52.0(41)

Reproduced with permission from The Royal Society of Chemistry.

I

10 Molecules with Ten or More Carbon Atoms

829

II

III

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Differences in the similar bond lengths and angles within each conformer and structural differences between the major and minor conformers were restrained to the values from B3LYP-GD3/6-311G(2d,p) computations.

b

The B3LYP and B3LYP-GD3 computations (with the 6-311G(2d,p) basis set) predicted the existence of four conformers differing in the torsional angles around the central Si–Si bond; three of them with the anticlinal, – anticlinal and synclinal H(2)–Si(2)–Si(1)–H(1) torsional angles were predicted to exist in the gas phase at the temperature of the GED experiment (Tnozzle = 412…443 K) in sufficient amounts. The best fit to experimental intensities was obtained for a mixture of three conformers, I, II and III, in the following ratio: 59.2(100) : 30.0(100) : 10.8 (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from DFT computation. Schwabedissen J, Lane PD, Masters SL, Hassler K, Wann DA (2014) Gas-phase structures of sterically crowded disilanes studied by electron diffraction and quantum chemical methods: 1,1,2,2-tetrakis(trimethylsilyl)disilane and 1,1,2,2-tetrakis(trimethylsilyl)dimethyldisilane. Dalton Trans 43 (26):10175-10182

920 CAS RN: 32286-53-6 MGD RN: 518162 GED augmented by DFT computations

Bonds Si(1)–Si(2) Si(1)–Si(5) Si(1)–Si(6) Si(1)–C(55) Bond angles Si(5)–Si(1)–Si(6) Si(2)–Si(1)–Si(5) Si(2)–Si(1)–Si(6) Si(2)–Si(1)–C(55)

1,1,1,2,3,4,4,4-Octamethyl-2,3-bis(trimethylsilyl)tetrasilane C14H42Si6 C2 (I) C2 (II) C2 (III)

I 2.368(1) 2.362(1) 2.365(1) 1.933(18)

I 109.3(11) 113.4(8) 117.9(4) 103.8(6)

rh1 [Å] a,b II 2.370(1) 2.365(1) 2.362(1) 1.934(18)

θh1 [deg] a,b II 110.1(11) 112.0(8) 117.3(4) 106.3(6)

III 2.367(1) 2.372(1) 2.368(1) 1.929(18)

III 108.7(12) 113.7(8) 114.8(4) 106.5(6)

830

10 Molecules with Ten or More Carbon Atoms

C(55)–Si(1)–Si(5) C(55)–Si(1)–Si(6) Si(1)–Si(5)–C(31) Si(1)–Si(6)–C(51) Si–C–H c

106.2(7) 107.0(2) 111.7(8) 113.5(4) 112.0(4)

105.2(7) 106.9(2) 113.6(8) 111.8(4)

τh1 [deg] a

Dihedral angle

I -47.0(6)

C(56)–Si(2)–Si(1)–C(55)

II -73.3(26)

109.2(7) 108.4(2) 110.9(8) 111.2(4)

III -161.9(16)

Reproduced with permission from The Royal Society of Chemistry.

I

II

III

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Differences between the similar bond lengths and angles within each conformer and structural differences between the major and minor conformers were restrained to the values from B3LYP-GD3/6-311G(2d,p) computations. b

B3LYP and B3LYP-GD3 computations in conjunction with 6-311G(2d,p) basis set predicted existence of four conformers differing by the magnitude of the torsional angle around the central Si–Si bond; two of the conformers with the synclinal C(56)–Si(2)–Si(1)–C(55) torsion angles and one conformer with the antiperiplanar C(56)–Si(2)–Si(1)–C(55) dihedral angle were predicted to exist at the temperature of the GED experiment (Tnozzle = 431…448 K) in sufficient amounts. The best fit to experimental intensities was obtained for a mixture of three conformers, I, II and III, in amounts of 41.1(150), 45.0(150) and 13.9 %, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from DFT computation. Schwabedissen J, Lane PD, Masters SL, Hassler K, Wann DA (2014) Gas-phase structures of sterically crowded disilanes studied by electron diffraction and quantum chemical methods: 1,1,2,2-tetrakis(trimethylsilyl)disilane and 1,1,2,2-tetrakis(trimethylsilyl)dimethyldisilane. Dalton Trans 43 (26):10175-10182

921 CAS RN: 14640-64-3 MGD RN: 211489

Tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato-κO2,κO4)lanthanum Tris(hexafluoroacetylacetonato)lanthanum C15H3F18LaO6

10 Molecules with Ten or More Carbon Atoms

831

GED combined with MS and augmented by QC computations

Distances La–O C–O C–C(r) O…O C–C(m) C(m)–F La...C(r) bc

rh1[Å] a 2.402(10) b 1.261(9) b 1.401(5) b 2.729(30) 1.540(6) 1.344(4) b 3.939(17) 1.136(4)

Bond angles O–La–O C–C(r)–C O–C–C(m) C–C(m)–F La–O–C

θh1 [deg] d

Dihedral angles

τh1 [deg] d

f

ϕ φg γh

rg[Å] a 2.393(10) 1.264(9) 1.415(5) 2.726(30) 1.540(6) 1.344(4) 3.902(17)

O O

F3C

F3C

O La

O

D3

F3C

CF3

O CF3

O CF3

69.2(4) b 119.0(18) 116.2(13) b 110.9(2) b,e 138.2(13) b

24.8(113) b 16.2(26) 7.1(132) b

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Refined value, i.e. independent parameter. c b = r(O…O)/r(La–O) d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Average value. f Angle of the ligand rotation around the La…C(r) axis; ϕ = 0° for D3h overall symmetry. g Rotation angle of the upper O…O…O plane relative to the lower O…O…O plane; φ = 0° for D3h overall symmetry. h Torsional angle of the CF3 group; γ = 0° for the eclipsed position of this group with respect to the C–C(r) bond. In the GED experiment, the overheated vapor of the title compound was conditioned in the upper chamber of the double effusion cell at the temperature of 560…562(5) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated with harmonic force constants from HF/″large core″ECP(La), 6-31G*(C,O,F,H) computation. Rybkin VV, Tverdova NV, Girichev GV, Shlykov SA, Kuzmina NP, Zaitseva IG (2011) Composition of overheated vapors and molecular structure of monomeric tris-hexafluoroacetylacetonates of lanthanum, neodymium and samarium. J Mol Struct 1006 (1-3):173-179

922 CAS RN: 47814-18-6 MGD RN: 211662 GED combined with MS and

Tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato-κO2,κO4)neodymium Tris(hexafluoroacetylacetonato)neodymium C15H3F18NdO6 D3

832

10 Molecules with Ten or More Carbon Atoms

augmented by QC computations F3C

CF3

a

Distances Nd–O C–O C–C(r) O…O C–C(m) C(m)–F Nd...C(r) bc

rh1 [Å] 2.344(11) b 1.261(13) b 1.403(7) b 2.705(37) 1.542(7) 1.345(4) b 3.881(15) 1.154(6)

Bond angles O–Nd–O C–C(r)–C O–C–C(m) C–C(m)–F Nd–O–C

θh1 [deg] d

Dihedral angles

τh1 [deg] d

f

ϕ φg γh

a

rg [Å] 2.336(11) 1.263(13) 1.417(7) 2.700(37) 1.542(7) 1.345(4) 3.845(15)

O O

F3C

Nd O

F3C

O O CF3

O CF3

70.5(6) b 118.8(15) 115.8(11) b 110.8(3) b,e 138.2(17) b

27.9(101) b 18.3(20) 6.8(76) b

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Refined value, i.e. independent parameter. c b = r(O…O)/r(Nd–O) d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Average value. f Angle of the ligand rotation around the Nd…C(r) axis; ϕ = 0° for D3h overall symmetry. g Rotation angle of the upper O…O…O plane relative to the lower O…O…O plane; φ = 0° for D3h overall symmetry. h Torsional angle of the CF3 group; γ = 0° for the eclipsed position of this group with respect to the C–C(r) bond. In the GED experiment, the overheated vapor of the title compound was conditioned in the upper chamber of the double effusion cell at the temperature of 556…562(5) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated with harmonic force constants from HF/″large core″ECP(Nd),6-31G*(C,O,F,H) computation. Rybkin VV, Tverdova NV, Girichev GV, Shlykov SA, Kuzmina NP, Zaitseva IG (2011) Composition of overheated vapors and molecular structure of monomeric tris-hexafluoroacetylacetonates of lanthanum, neodymium and samarium. J Mol Struct 1006 (1-3):173-179

923 CAS RN: 14220-50-9 MGD RN: 211834 GED combined with MS and augmented by QC computations

Tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato-κO2,κO4)samarium Tris(hexafluoroacetylacetonato)samarium C15H3F18O6Sm D3

10 Molecules with Ten or More Carbon Atoms

Distances Sm–O C–O C–C(r) O…O C–C(m) C(m)–F Sm...C(r) bc

rh1[Å] a 2.317(10) b 1.260(8) b 1.402(6) b 2.712(26) 1.541(6) 1.344(3) b 3.848(13) 1.171(4)

Bond angles O–Sm–O C–C(r)–C O–C–C(m) C–C(m)–F Sm–O–C

θh1 [deg] d

Dihedral angles

τh1 [deg] d

f

ϕ φg γh

rg[Å] a 2.309(10) 1.262(8) 1.415(6) 2.699(26) 1.541(6) 1.345(3) 3.814(13)

833 F3C

CF3

O O

F3C

Sm O

F3C

O O CF3

O CF3

71.7(4) b 118.4(19) 116.8(10) b 110.9(2) b,e 137.2(12) b

27.8(19) b 18.6(5) 15.1(37) b

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Refined value, i.e. independent parameter. c b = r(O…O)/r(Sm–O) d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Average value. f Angle of the ligand rotation around the Sm…C(r) axis; ϕ = 0° for D3h overall symmetry. g Rotation angle of the upper O…O…O plane relative to the lower O…O…O plane; φ = 0° for D3h overall symmetry. h Torsional angle of the CF3 group; γ = 0° for the eclipsed position of this group with respect to the C–C(r) bond. In the GED experiment, the overheated vapor of the title compound was conditioned in the upper chamber of the double effusion cell at the temperature of 516…518(5) K. Vibrational corrections to the experimental internuclear distances, ∆r = ra − rh1, were calculated with harmonic force constants from HF/″large core″ECP(Sm),6-31G*(C,O,F,H) computation. Rybkin VV, Tverdova NV, Girichev GV, Shlykov SA, Kuzmina NP, Zaitseva IG (2011) Composition of overheated vapors and molecular structure of monomeric tris-hexafluoroacetylacetonates of lanthanum, neodymium and samarium. J Mol Struct 1006 (1-3):173-179

924 CAS RN: 1616842-31-9 MGD RN: 538578 GED augmented by QC computations

1,2,3,4,5-Pentafluoro-6-(3-phenylpropyl)benzene C15H11F5 C1 (π-π)

834

Bonds C–C (in C6H5) C–C (in C6F5) C–C (backbone)

10 Molecules with Ten or More Carbon Atoms

rh1 [Å] a 1.396(1) b 1.391(1) b 1.568(5) b

F F

F

F

a

Bond angles C(7)–C(3ʹ)–C(2ʹ) C(6)–C(1ʹ)–C(2ʹ) C(1ʹ)–C(2ʹ)–C(3ʹ)

θh1 [deg]

Dihedral angles C(8)–C(7)–C(3ʹ)–C(2ʹ) C(5)–C(6)–C(1ʹ)–C(2ʹ) C(7)–C(3ʹ)–C(2ʹ)–C(1ʹ) C(6)–C(1ʹ)–C(2ʹ)–C(3ʹ)

τh1 [deg] a

F

115(3) 112(4) 112(3)

52(7) -73(6) 66(5) -100(6)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission. a b

Parenthesized uncertainties in units of the last significant digit are 3σ values. Mean value.

According to prediction of TPSS-D3/TZVP computation, the lowest-energy conformer of the title compound is stabilized due to intramolecular π-π interaction between the two phenyl rings. Only this conformer was detected by GED at Tnozzle = 383(5) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from computations at the level of theory as indicated above. Blomeyer S, Linnemannstöns M, Nissen JH, Paulus J, Neumann B, Stammler HG, Mitzel NW (2017) Intramolecular π-π interactions in flexibly linked partially fluorinated bisarenes in the gas phase. Angew Chem Int Ed / Angew Chem 56/129 (43/43):13259-13263/13443-13447

925 CAS RN: 62961-62-0 MGD RN: 385489 GED combined with MS and augmented by DFT computations

Distances C(2)=C(3) C(1)–C(2) C(9)–C(10) C(6)–C(7) C(7)–C(8) C(8)–C(9) C(4)–C(6) C(4)–C(10) C(3)–C(4) C(1)–C(5) C(14)–C(15) C(11)–C(12) C(12)–C(13) C(13)–C(14) C(5)–C(11) C(5)–C(15)

rh1 [Å] a,b 1.381(3) 1 1.441(3) 1 1.392(3) 1 1.393(3) 1 1.396(3) 1 1.397(3) 1 1.405(3) 1 1.405(3) 1 1.481(3) 1 1.499(3) 1 1.392(3) 1 1.394(3) 1 1.396(3) 1 1.397(3) 1 1.404(3) 1 1.404(3) 1

(2Z)-3-Hydroxy-1,3-diphenyl-2-propen-1-one

O

OH

C15H12O2 C1

10 Molecules with Ten or More Carbon Atoms

C(1)=O(2) C(3)–O(1) C(2)–H C(6)–H C(10)–H C(9)–H C(7)–H C(8)–H C(11)–H C(15)–H C(12)–H C(14)–H C(13)–H O(1)–H(1) O(2)...H(1) O(1)...O(2)

1.252(5) 1.317(5) 1.078(5) 2 1.083(5) 2 1.084(5) 2 1.085(5) 2 1.085(5) 2 1.085(5) 2 1.084(5) 2 1.084(5) 2 1.085(5) 2 1.085(5) 2 1.086(5) 2 1.020(5) 2 1.599(21) c 2.532(17) c

Bond angles C(3)=C(2)–C(1) C(2)=C(3)–O(1) C(2)–C(1)=O(2) O(1)–C(3)–C(4) O(2)=C(1)–C(5) C(3)–O(1)–H(1) C(3)–C(4)–C(6) C(6)–C(4)–C(10) C(7)–C(6)–C(4) C(8)–C(7)–C(6) C(9)–C(8)–C(7) C(10)–C(9)–C(8) C(4)–C(10)–C(9) C(1)–C(5)–C(15) C(11)–C(5)–C(15) C(5)–C(15)–C(14) C(15)–C(14)–C(13) C(14)–C(13)–C(12) C(13)–C(12)–C(11) C(12)–C(11)–C(5)

θh1 [deg] a

Dihedral angles C(4)–C(3)=C(2)…O(1) C(5)–C(1)–C(2)…O(2) C(6)–C(4)–C(3)–O(1) C(15)–C(5)–C(1)=O(2)

τh1 [deg] a

835

120.9(8) 121.0(8) 121.0(8) 115.1(10) 119.9(10) 105.3 d 119.3 d 118.7 d 120.6 d 120.2 d 119.7 d 120.2 d 120.6 d 118.1 d 118.8 d 120.7 d 120.0 d 119.8 d 120.1 d 120.6 d

179.2 d 179.4 d 15.1(50) 12.1(58)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r for the distances and 3σ values for the angles. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/cc-pVTZ computation. c Dependent parameter. d Assumed at the value from computation as indicated above. The GED experiment was carried out at Teffusion cell = 380(5) K. Dibenzoylmethane was found to exist as enol tautomer (100(5)%). According to prediction of B3LYP/cc-pVTZ calculation, the enol ring was assumed to be planar.

836

10 Molecules with Ten or More Carbon Atoms

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force field from computation at the level of theory as indicated above. Belova NV, Oberhammer H, Girichev GV (2011) Tautomeric and conformational properties of dibenzoylmethane, C6H5-C(O)-CH2-C(O)-C6H5: Gas-phase electron diffraction and quantum chemical study. Struct Chem 22 (2):269-277

Tris(2,4-pentanedionato-κO,κO’)cobalt Tris(acetylacetonato)cobalt C15H21CoO6 D3

926 CAS RN: 34248-50-5 MGD RN: 343622 GED/MS augmented by DFT computations

Bonds Co–O O–C C–C(r) C–C(m) C(m)–H(1) C(m)–H(2,3)

rh1 [Å] a 1.893(4) 1.274(3) 1.401(3) 1.510(3) b 1.071(11) 1.074(11) b,c

Bond angles Co–O–C O–Co–O C–C(r)–C O–C–C(r) O–C–C(m) C–C(m)–H H–C(m)–H

θh1 [deg] d

Dihedral angles

τh1 [deg] d

e

ϕ φf γg

rg [Å] a 1.894(4) 1.276(3) 1.404(3) 1.512(3) 1.075(11) 1.079(11)

124.9(3) 95.2(1) 123.2(4) b 125.9(3) b 114.4(5) 111.2(24) 109.3(122)

35.6(7) 32.5(5) b 0.9(170)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Dependent parameter. c Differences between the C(m)–H bond lengths were assumed at the values from calculation at the level of theory as indicated below. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Torsional angle of the ligand relative to its C2 axis from the D3h overall symmetry. f Torsional angle of the upper and lower O…O…O triangles relative to each other from D3h overall symmetry. g Torsional angle of the methyl group, γ = 0° when one C(m)–H bond is eclipsing the C–C(r) bond. The GED experiment was carried out at Teffusion cell = 423(6) K. Vibrational corrections to the experimental internuclear distances, Δrh1 = ra − rh1, were calculated using harmonic force constants from BP86/6-311++G*(Co),cc-pVTZ(O,C,H) computation.

10 Molecules with Ten or More Carbon Atoms

837

Tverdova NV, Girichev GV, Shlykov SA, Kuz'mina NP, Petrova AA, Zaitseva IG (2013) A study of the structure and energy of β-diketonates. XVIII. Molecular structure of chromium and cobalt tris-acetylacetonates according to quantum chemical calculations and gas electron diffraction. J Struct Chem (Engl Transl)/Zh Strukt Khim 54/54 (5/5):863-875/825-837

Tris(2,4-pentanedionato-κO,κO')chromium Tris(acetylacetonato)chromium C15H21CrO6 D3

927 CAS RN: 21679-31-2 MGD RN: 343818 GED combined with MS and augmented by DFT computations

Bonds Cr–O O–C C–C(r) C–C(m) C(m)–H(1) C(m)–H(2,3)

rh1 [Å] a 1.960(4) 1.279(3) 1.404(3) 1.509(3) b 1.098(6) 1.102(6) b,c

Bond angles Cr–O–C O–Cr–O C–C(r)–C O–C–C(r) O–C–C(m) C–C(m)–H H–C(m)–H

θh1 [deg] d

Dihedral angles

τh1 [deg] d

e

ϕ φf γg

rg [Å] a 1.970(4) 1.279(3) 1.397(3) 1.512(3) 1.103(6) 1.106(6)

125.5(3) 92.9(1) 124.3(4) b 125.9(3) b 114.4(4) 112.0(14) 109.4(96)

37.1(7) 32.4(5) b 18.7(240)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Dependent parameter. c Differences between the C(m)–H bond lengths were assumed at the values from calculation at the level of theory as indicated below. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Torsional angle of a ligand relative to its C2 axis from the D3h overall symmetry. f Torsional angle of the upper and lower O…O…O triangles relative to each other from the D3h overall symmetry. g Torsional angle of the methyl group, γ = 0° when one C(m)–H bond is eclipsing the C–C(r) bond. The GED experiment was carried out at Teffusion cell = 386(8) K. Vibrational corrections to the experimental internuclear distances, Δrh1 = ra − rh1, were calculated using quadratic force field from BP86/6-311++G*(Cr),cc-pVTZ (O,C,H) computation. Tverdova NV, Girichev GV, Shlykov SA, Kuz'mina NP, Petrova AA, Zaitseva IG (2013) A study of the structure and energy of β-diketonates. XVIII. Molecular structure of chromium and cobalt tris-acetylacetonates

838

10 Molecules with Ten or More Carbon Atoms

according to quantum chemical calculations and gas electron diffraction. J Struct Chem (Engl Transl) / Zh Strukt Khim 54/54 (5/5):863-875/825-837

928 CAS RN: 14284-89-0 MGD RN: 540027 GED combined with MS and augmented by DFT computations

Tris(2,4-pentanedionato-κO2,κO4)manganese Tris(acetylacetonato)manganese C15H21MnO6 H 3C C2 H3C O O

Bonds Mn–O(3) O(3)–C(5) C(5)–C(6) Mn–O(1) Mn–O(2) O(1)–C(1) O(2)–C(2) C(1)–C(3) C(2)–C(3) C(5)–C(7) C(1)–C(4) C(2)–C(4)

rh1 [Å] a,b 1.946(5) 1 1.275(3) 2 1.406(3) 3 2.157(16) 1.932(5) 1 1.257(3) 2 1.285(3) 2 1.425(3) 3 1.397(3) 3 1.512(5) 4 1.519(5) 4 1.515(5) 4

Bond angles O(3)–Mn–O(3ʹ) Mn–O(3)–C(5) C(5)–C(6)–C(5ʹ) C(6)–C(5)–C(7) O(1)–Mn–O(2) Mn–O(1)–C(1) Mn–O(2)–C(2) C(1)–C(3)–C(2)

θh1 [deg] b,c

Dihedral angles O(3ʹ)–Mn–O(3)–C(5) O(2)–Mn–O(1)–C(1)

τh1 [deg] c,d

O

CH3

Mn O

O O

CH3

H 3C H 3C

91.4(27) 126.7(20) 5 120.9(60) 117.5(20) 88.9(16) 124.2(20) 5 128.8(20) 5 121.9(60)

0(6) 3(6)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from DFT computation at the level of theory as indicated below. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d The ligand on the C2 axis was found to be planar, and two other ligands were determined to be essentially planar. According to predictions of UB3LYP/cc-pVTZ computations, the title molecule has C2 symmetry in the lowest energy high-spin electronic state (5B). In the GED analysis (Teffusion cell = 398 K), the title compound was found to exist as a single conformer with a tetragonal elongated MnO6 octahedron in a mixture with acetylacetonate (47(2) mol%), arising due to partial thermal decomposition of the sample.

10 Molecules with Ten or More Carbon Atoms

839

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from DFT calculation. Berger RJF, Girichev GV, Giricheva NI, Petrova AA, Tverdova NV (2017) The structure of Mn(acac)3 experimental evidence of a static Jahn-Teller effect in the gas phase. Angew Chem Int Ed / Angew Chem 56 /129 (49/49):15751-15754/15958-15961

[2,2'-[1,2-Ethanediylbis[(nitrilo-κN)methylidyne]]bis[phenolato-κO]copper 929 CAS RN: 14167-15-8 Bis(salicylidene)ethylenediiminocopper MGD RN: 364250 C16H14CuN2O2 GED combined with MS and C2 augmented by QC computations N

N

Distances C(12)–C(13) C(7)–C(8) C(12)–N(2) N(2)=C(7) C–H C(6)–O(4) Cu–N(2) Cu–O(4) N...N O...O N...O

rh1[Å] a,b 1.543(3) 1 1.431(3) 1 1.469(8) 2 1.308(8) 2 1.131(5) c,d 1.321(10) d 1.927(17) d 1.921(15) 2.559(17) 2.687(47) 2.815(18)

Bond angles C(13)−C(12)−N(2) C(12)–N(2)=C(7) N(2)=C(7)–C(8) C(7)–C(8)–C(14) O(4)–C(6)–C(8) N−Cu–N O−Cu–O N−Cu–O

θh1 [deg] e

Dihedral and other angles N(2)–C(12)−C(13)–N(3) C(7)=N(2)–C(12)−C(13) C(8)–C(7)=N(2)–C(12) C(14)–C(8)–C(7)=N(2) O(4)…N(2)…O(5)…N(3) Σ(cycle) f Σ(N) g

τh1 [deg] e

Cu O

O

105.3(15) d 113.5(13) d 121.5(13) d 117.2(5) d 127.4(7) d 83.2(7) 88.8(17) 94.1(7)

-44.9(21) d -163.8(22) d -172.4(40) d -170.5(39) d 176.0(97) 521.0(25) 355.9(24)

Reproduced with permission of SNCSC. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscript were refined in one group. Difference between parameters in each group was assumed at the value from computation at the level of theory as indicated below. c Average value. d Refined parameter. e Parenthesized uncertainties in units of the last significant digit are 2.5σ values. f Sum of the bond angles in the CuN2C2 ring.

840 g

10 Molecules with Ten or More Carbon Atoms

Sum of the valence angles around the nitrogen atom.

The combined GED/MS experiment was carried out at Teffusion cell = 574(5) K. The title molecule was found to exist in monomeric form. No any byproduct was detected in the mass spectrum. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from UB3LYP/6-31G* computation. The benzene rings were assumed to be planar. The five-membered ring CuN2C2 was found to be close to planar. Giricheva NI, Girichev GV, Kuzmina NP, Medvedeva YS, Rogachev AY (2009) Structure of the Cu(salen) molecule CuO2N2C16H14 according to gas-phase electron diffraction data and quantum chemical calculations. J Struct Chem (Engl Transl)/Zh Strukt Khim 50/50(1/1):52-59/58-65

[[2,2'-[1,2-Ethanediylbis(nitrilo-κN)methylidyne]]bis[phenolato-κO]]zinc 930 CAS RN: 14167-22-7 Bis(salicylidene)ethylenediiminozinc MGD RN: 362323 C16H14N2O2Zn GED combined with MS and C2 augmented by DFT computations N

N

Distances C(1)–C(2) C(5)–C(6) C(1)–N(3) N(3)=C(5) C–H C(11)–O(12) Zn–N(3) Zn–O(12) N...N O...O N...O

rh1 [Å] a,b 1.557(3) 1 1.440(3) 1 1.471(9) 2 1.312(9) 2 1.093(5) c 1.298(9) 2.027(7) 1.902(7) d 2.634(26) d 3.076(73) d 2.820(17) d

Bond angles C(2)–C(1)–N(3) C(1)–N(3)=C(5) N(3)=C(5)–C(6) C(5)–C(6)–C(7) O(12)–C(11)–C(6) N–Zn–N O–Zn–O N–Zn–O

θh1 [deg] e

Dihedral angles N(3)–C(1)–C(2)–N(4) C(5)=N(3)–C(1)–C(2) C(6)–C(5)=N(3)–C(1) C(7)–C(6)–C(5)=N(3) C(8)–C(7)–C(6)–C(5) O(12)…N(3)…O(20)…N(4)

τh1 [deg] e

Zn O

O

106.1(11) 116.6(12) 121.9(13) 118.3(11) 124.9(9) 80.6(10) d 108.0(38) d 91.7(8) d

46.6(27) 119.6(43) 177.3(61) -156.4(51) -176.0(112) -129.3(63) d

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r.

10 Molecules with Ten or More Carbon Atoms

841

b

Parameters with equal superscripts were refined in one group; difference between parameters in each group was assumed at the value from computation at the level of theory as indicated below. c Average value. d Dependent parameter. e Parenthesized uncertainties in units of the last significant digit are 2.5σ values. The combined GED/MS experiment was carried out at Teffusion cell=651(5) K. The title compound was found to exist as a single molecular form. The benzene rings were assumed to be planar. The central ZnC2N2 unit was found to have a twist conformation with the sum of the angles in this five-membered ring of 520.6(23)°. The sum of the angles around each of the nitrogen atoms was determined to be 355.3(18)° pointing to almost planar configuration of the bonds around these atoms. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/6-31G* computation. Girichev GV, Giricheva NI, Tverdova NV, Simakov AO, Kuz'mina NP, Kotova OV (2010) Geometric and electronic structure of an N,N'-ethylene-bis(salicylaldiminato)zinc(II) molecule, ZnO2N2C16H14. J Struct Chem (Engl Transl)/Zh Strukt Khim 51/51(2/2):223-230/237-245

931 CAS RN: 84442-89-7 MGD RN: 538228 GED augmented by QC computations

1-[2-(Dimethylphenylsilyl)ethyl]-2,3,4,5,6-pentafluorobenzene Dimethyl[2-(pentafluorophenyl)ethyl]phenylsilane C16H15F5Si C1 (π-π) C1 (σ-π) F H C CH 3

3

F

Si

Bonds Si–C C–C (in C6H5) C–C (in C6F5) C–C (backbone)

a

rh1 [Å] σ-π 1.876(3) b 1.882(3) b b 1.397(1) 1.398(1) b b 1.391(1) 1.393(1) b b 1.578(14) 1.577(14) b

π-π

π-π

θh1 [deg] a σ-π

π-π

τh1 [deg] a σ-π

Bond angles C(7)–Si–C C(1)–C(1ʹ)–C(2ʹ) Si–C(2ʹ)–C(1ʹ) Dihedral angles C(8)–C(7)–Si–C(2ʹ) C(2)–C(1)–C(1ʹ)–C(2ʹ) C(7)–Si–C(2ʹ)–C(1ʹ) C(1)–C(1ʹ)–C(2ʹ)–Si

112(5) 113(4) 115(4)

114(8) 72(6) -74(7) 56(7)

b

70(9) 114(8) -172(9) -56(9)

Parenthesized uncertainties in units of the last significant digit are 3σ values. Mean value.

F

F

105(6) 113(6) 118(5)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

F

π-π

842

10 Molecules with Ten or More Carbon Atoms

According to prediction of TPSS-D3/TZVP computation, the lowest-energy conformer of the title compound is stabilized due to intramolecular π-π interaction between the two phenyl rings. The other conformer, stabilized by the σ-π interaction between the methyl and pentafluorophenyl groups, was predicted to be over global minimum of PES by 16.5 kJ mol-1. The GED experiment was carried out at Tnozzle = 383(5) K. The best fit to experimental intensities was obtained for the mixture of the π -π and σ-π conformers in amounts of 85(26) and 15(26) %, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from computations at the level of theory as indicated above. Selected parameters are presented.

σ-π

Blomeyer S, Linnemannstöns M, Nissen JH, Paulus J, Neumann B, Stammler HG, Mitzel NW (2017) Intramolecular π-π interactions in flexibly linked partially fluorinated bisarenes in the gas phase. Angew Chem Int Ed / Angew Chem 56/129 (43/43):13259-13263/13443-13447

932 CAS RN: MGD RN: 538394 GED augmented by QC computations

1-[Dimethyl(2-phenylethyl)silyl]-2,3,4,5,6-pentafluorobenzene Dimethyl(pentafluorophenyl)(2-phenylethyl]silane C16H15F5Si C1 (π-π) C1 (σ-π) H 3C

Bonds Si–C C–C (C6H5) C–C (C6F5) C–C (backbone) Bond angles C(7)–C(2ʹ)–C(1ʹ) C(1)–Si–C Si–C(1ʹ)–C(2ʹ)

rh1 [Å] a π-π σ-π 1.883(2) b 1.886(2) b b 1.396(1) 1.396(1) b b 1.392(1) 1.393(1) b b 1.560(9) 1.560(9) b

π-π

110(2) 118(2) 108(3)

CH3

F

Si

F

F

F F

θh1 [deg] a σ-π

112(5) 117(5) 105(5)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a b

Parenthesized uncertainties in units of the last significant digit are 3σ values. Mean value.

According to prediction of TPSS-D3/TZVP computation, the lowest-energy conformer of the title compound is stabilized due to intramolecular π-π interaction between the two phenyl rings. Another conformer, stabilized by σ[CH(methyl)]…π(phenyl) interaction, was predicted to be higher in energy by 13.9 kJ mol-1.

10 Molecules with Ten or More Carbon Atoms

843

The GED experiment was carried out at Tnozzle = 383(5) K. Presence of the σ-π conformer could not be excluded in the GED analysis. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from computations at the level of theory as indicated above. Dihedral angles given in the paper for π-π conformer do not correspond to the π stacking structure. Therefore, they are not presented here.

π-π

σ-π

Blomeyer S, Linnemannstöns M, Nissen JH, Paulus J, Neumann B, Stammler HG, Mitzel NW (2017) Intramolecular π-π interactions in flexibly linked partially fluorinated bisarenes in the gas phase. Angew Chem Int Ed/Angew Chem 56/129 (43/43):13259-13263/13443-13447

1,3,5,7,9,11,13,15-Octaethenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane Octavinyloctasilsesquioxane C16H24O12Si8 D4

933 CAS RN: 69655-76-1 MGD RN: 384757 GED augmented by DFT computations

H 2C

H 2C H2C

a

Bonds C–H C–C Si–C Si–O

rg [Å] 1.099(5) b,c 1.317(8) 1.815(4) 1.6140(9)

Bond angles C–C–H Si–C–H Si–C–C Si–O–Si

θg [deg] a

Si O

H 2C

O

Si

O

Si

O

O Si

O O

Si O Si

CH2

Si

O

O

O

CH2

Si

CH2

O CH2

122.3(8) c 119.4(9) c 122.1(8) 146.0(3)

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. b Average value. c Restrained to the value close to that from B3LYP/6-311++G(3df,3pd) computation. The GED experiment was carried out at Tnozzle of 220 and 235 K at the long and short nozzle-to-film distances, respectively. Local Oh symmetry was assumed for the central Si8O12 fragment.

844

10 Molecules with Ten or More Carbon Atoms

Wann DA, Dickson CN, Lickiss PD, Robertson HE, Rankin DWH (2011) The gas-phase equilibrium structures of Si8O12(OSiMe3)8 and Si8O12(CHCH2)8. Inorg Chem 50 (7):2988-2994

934 CAS RN: 124235-53-6 MGD RN: 362519 GED augmented by QC computations

Bis[(1,1-dimethylethyl)imino]bis(2-methylpropanaminato)tungsten Bis(tert-butylimido)bis(tert-butylamido)tungsten C16H38N4W C1 (I) C2 (II) H 3C

Bonds C–H N–H N–C(4,5) N–C(2,3) C–C W(1)–N(2) W(1)–N(3) W(1)–N(4) W(1)–N(5) Bond angles W–N–H N–C–C C–C–H N(2)–W(1)–N(3) N(2)–W(1)–N(4) N(2)–W(1)–N(5) N(3)–W(1)–N(4) N(3)–W(1)–N(5) N(4)–W(1)–N(5) W(1)–N(2)–C(2) W(1)–N(3)–C(3) W(1)–N(4)–C(4) W(1)–N(5)–C(5) W(1)–N(2)–H W(1)–N(3)–H Dihedral angles H–N–W–N(H) N(2)–W…X–N(4) g twist(HN(3)butyl) h twist(HN(2)butyl) h twist(N(4)–C) i twist(N(5)–C) i twist(N(3)–C) i twist(N(2)–C) i drop(N(3)) j drop(N(2)) j twist(methyl) k

CH3

CH3 CH3

a

C1 1.109(2) b 1.013(5) b,c 1.458(5) b 1.455(8) b 1.538(2) b 1.996(3) d 1.996(3) d 1.769(2) d 1.759(2) d

rh1 [Å] C2 1.109(2) b 1.013(5) b,c 1.458(5) b 1.455(8) b 1.538(2) b 1.996(2) d 1.764(3) d

θh1 [deg] a

C1 112.6(10) b,c 109.3(4) b,c 112.0(4) b 113.8(22) e 109.0(7) e 103.4(10) e 108.6(7) e 105.6(10) e 116.5(9) e 133.6(10) e 136.5(10) e 162.3(10) e 164.7(10) e 113.6(10) e 111.6(10) e

C1

C2 114.8(10) c 106.7(7) b 110.0(12) b,c 111.0(11) e 112.0(16) e 103.1(15) e 103.1(15) e 112.0(16) e 115.9(11) e 133.4(10) e 164.0(10) e 114.8(10) c

τh1 [deg] a,f

151.1(48) c -133.4(36) c 30.0(29) c 19.3(30) c -140.8(53) c 40.9(45) c 15.2(21) c 12.5(20) c 179.5(46)

C2 117.0(41) c 96.1(18) 61.9(49) 61.1(77) 13.4(10) 160.0(42)

Reprinted with permission. Copyright 20009 American Chemical Society.

HN H3C H 3C

N

CH3

W NH

CH3 N

H3C H 3C

CH3

CH3

10 Molecules with Ten or More Carbon Atoms

I

845

II

a

Parenthesized uncertainties in units of the last significant digit are probably the estimated standard deviations. Average value. c Restrained to the value from B3PW91/LanL2DZ(W),6-31G*(H,C,N) computation. d Derived from the refined average value of r(W−N) and difference between them. e Derived from the refined average parameter (∠(N–W–N), ∠(W–N–C) or ∠(W–N–H), respectively) and parameter differences. f All torsion angles were defined to have the same signs for rotations of the respective groups in the same sense. g X is a dummy atom with coordinates (0.0, 1.0, 0.0) lying in a positive direction on the y axis. h Torsion angle of the N-tert-butyl group around the W−N bond, H–N–W–C. i Torsion angle of the tert-butyl group around the corresponding N–C bond. j Drop of the tert-butyl group out of the respective W−N−H plane. k Torsion angle of methyl group around the C−C bond. b

The GED experiment was carried out at Tnozzle of 429 and 450 K at the long and short nozzle-to-plate distances, respectively. Two conformers, I (C1 point-group symmetry) and II (Cs) were predicted by computation at the B3PW91/LanL2DZ(W),6-31G*(H,C,N) level of theory and considered in the GED analysis. The best fit to experimental intensities was obtained for the ratio of the conformers C1 : Cs = 31(1) : 69(1) (in %). Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from computation at the level of theory as indicated above. Choujaa H, Cosham SD, Johnson AL, Kafka GR, Mahon MF, Masters SL, Molloy KC, Rankin DWH, Robertson HE (2009) Structural tungsten-imido chemistry: The gas-phase structure of W(NBut)2(NHBut)2 and the solid-state structures of novel heterobimetallic W/N/M (M = Rh, Pd, Zn) species. Inorg Chem 48 (5):22892299 935 [25H,27H-Tetrakis[1,2,5]thiadiazolo[3,4-b:3',4'-g:3'',4''-l:3''',4'''-q]porphyrazin-14-SIVCAS RN: 221524-82-9 ato-κN25,κN26,κN27,κN28]zinc MGD RN: 539471 C16N16S4Zn GED combined with MS and D4h augmented by DFT computations

Bonds Zn–N(1) N(1)–C(1) C(1)–N(2) C(2)–N(3)

rh1 [Å] a 2.023(12) 1.382(4) b 1.324(4) 1.322(4)

846

N(3)–S C(1)–C(2) C(2)–C(2ʹ)

10 Molecules with Ten or More Carbon Atoms S

1.658(4) b 1.448(6) b 1.411(6)

N

N

Bond angles Zn–N(1)–C(1) C(1)–C(2)–C(2ʹ) N(1)–C(1)–C(2) C(2ʹ)–C(2)–N(3) C(1)–N(1)–C(1ʹ) C(1)–N(2)–C N(3)–S–N(3ʹ)

θh1 [deg] a b

124.2(9) 107.7(10) 106.5(5) b 116.1(7) b 111.6(6) 124.5(7) 101.8(10)

N

N

N

N

N

S

N

Zn

N

S

N

N

N

N

N

N

N S

Reproduced with permission of ISUCT Publishing.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r for the bond lengths and 3σ values for the angles. b Independent parameters. The GED experiment was carried out at Teffusion cell = 860(5) K. The title compound was found to be present together with its decomposition product, 1,2,5-thiadiazole-3,4-dicarbonitrile (C4N4S), in the ratio C16N16S4Zn : C4N4S = 10 : 90 (in mol%). Differences between similar parameters were assumed at the values from B3LYP/cc-pVTZ computations. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force field from DFT computation. Tverdova NV, Giricheva NI, Savelyev DS, Mikhailov MS, Vogt N, Koifman OI, Stuzhin PA, Girichev GV (2017) Molecular structure of tetrakis(1,2,5-thiadiazolo)-porphyrazinatozinc(II) in gaseous phase. Macroheterocycles 10(1): 27-30

936 CAS RN: 1109-15-5 MGD RN: 573175 GED supplemented by DFT computations

Bonds B–C(1) C(1)–C(2) C(2)–C(3) C(3)–C(4) C(2)–F C(3)–F C(4)–F

Tris(2,3,4,5,6-pentafluorophenyl)borane C18BF15 D3

F

re [Å] a 1.539(8) 1.392(1) b 1.379(1) b 1.383(1) b 1.335(1) b 1.327(1) b 1.322(1) b

F

F

F

F F

F

B

F

F

F F

F

F

F F

10 Molecules with Ten or More Carbon Atoms

Bond angles B–C–C C(1)–C(2)–C(3) C(1)–C(2)–F C(2)–C(3)–F C–B–C

θe [deg] a

Dihedral angle C(1')–B–C(1)–C(2)

τe [deg] a

847

122.6(3) 122.3(5) 118.7(5) 120.8(7) 120.0 c

40.6(3)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. b The C–C and C–F bond lengths were refined in one group; differences between these parameters were fixed at the values from B3LYP/6-311G(2d) computation. c Assumed. The GED experiment was carried out at Tnozzle = 422 K. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with quadratic and cubic force constants from computation at the level of theory as indicated above by taking into account nonlinear kinematic effects. Körte LA, Schwabedissen J, Soffner M, Blomeyer S, Reuter CG, Vishnevskiy YV, Neumann B, Stammler HG, Mitzel NW (2017) Tris(perfluorotolyl)borane - a boron Lewis superacid. Angew Chem Int Ed / Angew Chem 56/129 (29/29):8578-8582/8701-8705

937 CAS RN: 603-33-8 MGD RN: 382703 GED augmented by QC computations

Triphenylbismuthine C18H15Bi C3

Bonds Bi–C C(1)–C(4) C(4)–C(2) C(2)–C(6) C(6)–C(3) C(3)–C(5) C(5)–C(1) C(5)–H C(1)–H C(4)–H C(2)–H C(6)–H

rh1 [Å] a 2.263(3) 1.398(10) b 1.400(10) b 1.400(11) b 1.398(11) b 1.401(9) b 1.392(10) b 1.065(10) b 1.065(10) b 1.065(10) b 1.064(10) b 1.067(9) b

Angles C(1)–C(4)–C(2) C(3)–C(5)–C(1) C(2)–C(6)–C(3) C–Bi–C

θh1 [deg] a

119.84(87) b 119.78(83) b 119.16(51) b 94.7(9)

Bi

848

10 Molecules with Ten or More Carbon Atoms

αc

31.9(7)

Dihedral angles C(6)–C(3)–Bi–C

τh1 [deg] a

τ

d

94.0(20) b 43.6(20) b

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviation. b Restrained to ab initio value. c Angle between the C3 axis and the Bi–C bond. d Angle between the C3 axis and the Bi–C–C(5) plane. The GED experiment was carried out at Tnozzle = 485(4) K. The title molecule was assumed to have C3 point-group symmetry. Each of the BiC6H5 subunits was assumed to be planar. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from MP2/TZVPP calculation. Berger RJF, Rettenwander D, Spirk S, Wolf C, Patzschke M, Ertl M, Monkowius U, Mitzel NW (2012) Relativistic effects in triphenylbismuth and their influence on molecular structure and spectroscopic properties. Phys Chem Chem Phys 14 (44):15520-15524

938 CAS RN: 789-25-3 MGD RN: 151937 GED augmented by QC computations

1,1',1''-Silylidynetrisbenzene Triphenylsilane C18H16Si C3

Bonds Si–C C–C C(1)–C(2) C(2)–C(3) C(3)–C(4) C–H

rg[Å] a 1.874(4) 1.402(3) b 1.409(3) 1.399 c 1.399 c 1.102(3) b

Bond angles C–Si–H C(1)–Si–C C(2)–C(1)–C(6) C(1)–C(2)–C(3) C(2)–C(3)–C(4) C(3)–C(4)–C(5)

θa [deg] a

Dihedral angle

τa [deg] a

τ1

f

108.6(4) 110.3(4) d 117.86 e 121.17 d 120.10 d 119.62 d

39(3)

Reproduced with permission of SNCSC [a].

SiH

10 Molecules with Ten or More Carbon Atoms

849

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including the estimated standard deviations, an experimental systematic error and the effect of the geometrical constraints adopted in the refinement. b Average value. c Difference to the C(1)–C(2) bond length was assumed to the value from B3LYP/6-311++G** calculation. d Derived parameter. e Assumed at the value from calculation as indicated above. f Torsional angle between the plane of the benzene ring and the plane defined by the Si–C bond and the C3 axis. The GED data from Ref. [b] (Tnozzle = 453 K) were reanalyzed. According to predictions of HF/6-31G* computations, two enantiomers are easily interconverting to each other; the phenyl groups are twisting with large amplitudes. a. Campanelli AR, Domenicano A, Ramondo F, Hargittai I (2011) Molecular structure and conformation of triphenylsilane from gas-phase electron diffraction and theoretical calculations, and structural variations in H4nSiPhn molecules (n = 1-4). Struct Chem 22 (2):361-369 b. Rozsondai B, Hargittai I (1987) The molecular structure of triphenylsilane from gas-phase electron diffraction. J Organomet Chem 334:269-276

939 CAS RN: 18851-47-3 MGD RN: 398368 MW augmented by DFT calculations Distances H…O' O…O' C(1)…C(1ꞌ)

Phenol trimer C18H18O3 C3 OH

[Å] a r (1) m 1.895(86) 2.760(70) 3.967(83)

Angles O…Oꞌ…Oꞌꞌ O-H…Oꞌ C(1)…Oꞌꞌ…Oꞌ C(1ꞌꞌ)-Oꞌꞌ…O

θ (1) [deg] a m

Dihedral angles C(1)…C(1ꞌ)…C(1ꞌꞌ) C(1)-O…Oꞌ-C(1ꞌ) O…Oꞌ-C(1ꞌ)–C(6ꞌ)

[deg] a θ (1) m

3

60.03(73) 147.1(16) -27.9(14) 114.0(16)

60.00(75) -5.9(28) 85.2(33)

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit.

The rotational spectra of the phenol trimer were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8 GHz. structure was determined from the ground-state rotational constants of seven isotopic species The partial r (1) m (main and six 13C) with some constraints from the M06-2X/6-311++G(d,p) structure.

850

10 Molecules with Ten or More Carbon Atoms

Seifert NA, Steber AL, Neill JL, Pérez C, Zaleski DP, Pate BH, Lesarri A (2013) The interplay of hydrogen bonding and dispersion in phenol dimer and trimer: structures from broadband rotational spectroscopy. Phys Chem Chem Phys 15(27):11468-11477

940 1,3,5,7,9,11-Hexakis[(trimethylsilyl)oxy]tetracyclo[5.5.1.13,11.15,9]hexasiloxane CAS RN: 75899-36-4 MGD RN: 356605 C18H54O15Si12 GED augmented D3h by DFT computations OSi(CH3)3 Si

a

Bonds Si–O Si–C C–H Si(1)–O(2) Si(1)–O(7) Si(1)–O(9) Si(12)–O(9)

re,MD [Å] 1.6189(9) b 1.863(3) b 1.093(4) b,c 1.625(3) d,e 1.622(4) d,e 1.579(4) d,e 1.643(4) d,e

Bond angles Si(1)–O(2)–Si(3) Si(1)–O(7)–Si(7) Si(1)–O(9)–Si(12) X…A…O f O–Si–C C–Si–C Si–C–H X…Si–O f O(9)–Si(12)–C(1) O(9)–Si(12)–C(2)

θe,MD [deg] a

(H3C)3SiO

Si (H3C)3SiO

129.2(7) 141.8(14) 142.7(10) 154.4(16) 106.9(4) b 111.5(10) 110.8(7) b 142.1(7) 107.5(5) d,g 106.2(5) d,g

Parenthesized uncertainties in units of the last significant digit are 1σ values. Average value. c Restrained to the value from B3LYP/6-311++G(3df,2pd) computation. b

O

O

O

Si O

Table 2 reproduced with permission from de Gruyter, Berlin.

a

O

Si

Si O

O O

O

OSi(CH3)3 OSi(CH3)3

Si OSi(CH3)3

10 Molecules with Ten or More Carbon Atoms

851

d

Dependent parameter. Differences between the Si–O bond lengths were restrained to the values from computation as indicated above. f X is the center of the triangle formed by three Si atoms and A is the midpoint between two Si atoms on that face. g Differences between the O–Si–C bond angles was restrained to the value from computation as indicated above. e

The GED experiment was carried out at Tnozzle of 441 and 461 K at the long and short nozzle-to-film distances, respectively. Anharmonic vibrational corrections to the experimental internuclear distances, ∆re,MD = ra − re,MD, were derived by MD simulations. The structure of the title molecule resembles that of zeolite moiety. Wann DA, Reilly AM, Rataboul F, Lickiss PD, Rankin DWH (2009) The gas-phase structure of the hexasilsesquioxane Si6O9(OSiMe3)6. Z Naturforsch B 64(11-12):1269-1275

941 1',3'-Dihydro-1',3',3'-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2'-[2H]indole] CAS RN: 1498-88-0 MGD RN: 367195 C19H18N2O3 TRED supported by C1 DFT computations H 3C CH 3

Ground electronic state

O N

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(7) C(7)–N(8) N(8)–C(9) C(9)–C(10) C(10)=C(11) C(11)–C(12) C(12)–C(13) C(13)–C(14) C(14)–C(15) C(15)–C(16) C(16)–C(17) C(17)–O O–C(9) C(9)–C(1) C(2)–C(7) C(12)–C(17) C(1)–C(1a) C(1)–C(1b) N(8)–C(8) C(14)–N N=O(1) N=O(2)

r [Å] a,b 1.512(3) 1.409(3) 1.427(3) 1.413(2) 1.418(3) 1.433(3) 1.424(5) 1.448(5) 1.503(2) 1.375(3) 1.471(3) 1.407(4) 1.405(3) 1.409(3) 1.396(3) 1.423(1) 1.380(4) 1.527(3) 1.604(4) 1.414(3) 1.426(3) 1.540(5) 1.494(4) 1.472(5) 1.412(7) 1.255(8) 1.254(8)

Bond angles and bond angle differences c C(9)–C(1)–C(2)

θ [deg] a,b 100.6(9)

O CH3

N O

852

10 Molecules with Ten or More Carbon Atoms

C(1)–C(2)–C(7) C(2)–C(7)–N(8) C(7)–N(8)–C(9) N(8)–C(9)–C(1) C(3)–C(2)–C(7)–C(1) C(6)–C(7)–C(2)–N(8) C(4)–C(3)–C(2) C(5)–C(4)–C(3) C(6)–C(5)–C(4) C(7)–C(6)–C(5) C(1)–C(9)–C(10) N(8)–C(9)–O C(10)–C(9)–O C(1)–C(9)–O N(8)–C(9)–C(10) C(9)–C(10)=C(11) C(10)=C(11)–C(12) C(11)–C(12)–C(17) C(12)–C(17)–O C(17)–O–C(9) C(13)–C(12)–C(17)–C(11) C(16)–C(17)–C(12)–O C(12)–C(13)–C(14) C(13)–C(14)–C(15) C(14)–C(15)–C(16) C(15)–C(16)–C(17) C(1a)–C(1)–C(2) C(1a)–C(1)–C(1b) C(1b)–C(1)–C(9) C(1a)–C(1)–C(9) C(1b)–C(1)–C(2) C(8)–N(8)–C(7)–C(9) N–C(14)–C(13)–C(15) O(1)=N–C(14) O(2)=N–C(14)–O(1)

109.1(4) 109.9(8) 108.5(5) 103.2(4) -10.5(2) -7.5(5) 119.4(2) 120.1(5) 121.2(4) 117.8(2) 115.8(2) 107.5(3) 111.2(3) 106.1(1) 112.4(3) 123.9(3) 121.6(4) 117.3(3) 121.8(3) 123.9(5) -4.7(3) 3.2(4) 119.5(3) 121.8(8) 119.3(3) 119.8(3) 108.6(3) 109.5(2) 112.5(6) 110.9(3) 114.5(2) 0.6(1) -0.17(4) 117.8(4) -6.7(4)

Dihedral angles C(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–C(7) C(2)–C(3)–C(4)–C(5) C(5)–C(6)–C(7)–C(2) C(7)–C(2)–C(3)–C(4) C(6)–C(7)–C(2)–C(3) C(1)–C(2)–C(7)–N(8) C(3)–C(2)–C(7)–N(8) C(6)–C(7)–C(2)–C(1) C(2)–C(7)–N(8)–C(9) C(7)–C(2)–C(1)–C(9) C(2)–C(1)–C(9)–N(8) C(7)–N(8)–C(9)–C(1) C(1a)–C(1)–C(9)–N(8) C(1a)–C(1)–C(2)–C(7) C(1b)–C(1)–C(9)–N(8) C(1b)–C(1)–C(2)–C(7) C(8)–N(8)–C(7)–C(2) C(8)–N(8)–C(9)–C(1) C(10)–C(9)–C(1)–C(2) C(10)–C(9)–N(8)–C(7) O–C(9)–C(1)–C(2) O–C(9)–N(8)–C(7)

τ [deg] a,b -0.24(2) 0.377(2) 0.11(1) -0.39(3) -0.12(3) 0.3(1) -1.9(2) -179.3(2) 177.6(1) -17.7(4) 18.2(3) -27.6(1) 28.3(3) 87.1(3) -98.2(4) -149.9(3) 139.0(2) -163.3(3) 174.1(2) -150.8(2) 153.7(2) 85.3(4) -83.6(2)

10 Molecules with Ten or More Carbon Atoms

C(11)=C(10)–C(9)–C(1) C(11)=C(10)–C(9)–N(8) C(17)–O–C(9)–C(1) C(17)–O–C(9)–N(8) C(9)–O–C(17)–C(12) C(9)–C(10)=C(11)–C(12) C(10)–C(9)–O–C(17) C(10)=C(11)–C(12)–C(17) O–C(9)–C(10)=C(11) O–C(17)–C(12)–C(11) O–C(17)–C(12)–C(13) C(11)–C(12)–C(17)–C(16) C(13)–C(12)–C(17)–C(16) C(13)–C(14)–C(15)–C(16) C(14)–C(15)–C(16)–C(17) C(14)–C(13)–C(12)–C(17) C(15)–C(16)–C(17)–C(12) C(15)–C(14)–C(13)–C(12) N–C(14)–C(15)–C(16) N–C(14)–C(13)–C(12) O(1)=N–C(14)–C(15) O(1)=N–C(14)–C(13) O(2)=N–C(14)–C(15) O(2)=N–C(14)–C(13)

853

-124.3(2) 117.4(2) 133.3(2) -116.8(2) -6.31(4) -0.5(1) 6.6(1) 1.4(1) -3.2(2) 1.97(3) -178.82(1) -178.74(2) 0.46(1) 0.080(2) 0.268(2) -0.116(4) -0.543(4) -0.156(2) 179.988(2) 179.936(2) -179.867(2) 0.044(2) 0.123(2) -179.967(2)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Type of parameters was not specified. c Bond angle differences presented as A(i)–A(j)–A(k)–A(l) are defined as A(i)–A(j)–A(k) – A(i)–A(j)–A(l). b

The reversible isomerization of the title molecule was studied by laser desorption-electron diffraction in order to determine the nascent product structures upon photo-excitation. The molecular structure of the closed spiropyran form in the ground electronic state (S0) was determined at 510 K. Starting values of refined parameters were taken from B3LYP/6-311G(d,p) computation. Gahlmann A, Lee I-R, Zewail AH (2010) Direct structural determination of conformations of photoswitchable molecules by laser desorption-electron diffraction. Angew Chem/Angew Chem Int Ed 122/49 (37/37):66746677/6524-6527 Excited electronic state

854

10 Molecules with Ten or More Carbon Atoms

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(7) C(7)–N(8) N(8)–C(9) C(9)–C(10) C(10)=C(11) C(11)–C(12) C(12)–C(13) C(13)–C(14) C(14)–C(15) C(15)–C(16) C(16)–C(17) C(17)–O O–C(9) C(9)–C(1) C(2)–C(7) C(12)–C(17) C(1)–C(1a) C(1)–C(1b) N(8)–C(8) C(14)–N N=O(1) N=O(2)

r [Å] a,b 1.551(16) 1.387(21) 1.404(22) 1.395(14) 1.402(20) 1.406(17) 1.446(26) 1.477(23) 1.508(13) 1.347(20) 1.460(11) 1.404(21) 1.400(18) 1.406(17) 1.393(19) 1.403(18) 1.365(11) 1.482(18) 1.620(14) 1.413(27) 1.407(19) 1.550(36) 1.544(35) 1.476(26) 1.429(49) 1.333(39) 1.331(38)

Bond angles and bond angle differences c C(9)–C(1)–C(2) C(1)–C(2)–C(7) C(2)–C(7)–N(8) C(7)–N(8)–C(9) N(8)–C(9)–C(1) C(3)–C(2)–C(7)–C(1) C(6)–C(7)–C(2)–N(8) C(4)–C(3)–C(2) C(5)–C(4)–C(3) C(6)–C(5)–C(4) C(7)–C(6)–C(5) C(1)–C(9)–C(10) N(8)–C(9)–O C(10)–C(9)–O C(1)–C(9)–O N(8)–C(9)–C(10) C(9)–C(10)=C(11) C(10)=C(11)–C(12) C(11)–C(12)–C(17) C(12)–C(17)–O C(17)–O–C(9) C(13)–C(12)–C(17)–C(11) C(16)–C(17)–C(12)–O C(12)–C(13)–C(14) C(13)–C(14)–C(15) C(14)–C(15)–C(16) C(15)–C(16)–C(17) C(1a)–C(1)–C(2)

θ [deg] a,b 100.4(24) 109.1(28) 110.3(26) 108.5(27) 102.9(12) -10.6(15) -7.7(23) 119.4(12) 120.3(29) 121.3(16) 117.9(22) 115.7(9) 107.9(8) 111.3(14) 106.0(7) 112.3(15) 123.5(16) 121.4(15) 117.3(20) 122.1(16) 123.7(16) -4.0(12) 3.1(22) 119.8(10) 120.8(48) 119.4(11) 120.2(21) 108.5(16)

10 Molecules with Ten or More Carbon Atoms

C(1a)–C(1)–C(1b) C(1b)–C(1)–C(9) C(1a)–C(1)–C(9) C(1b)–C(1)–C(2) C(8)–N(8)–C(7)–C(9) N–C(14)–C(13)–C(15) O(1)=N–C(14) O(2)=N–C(14)–O(1)

109.4(10) 112.5(30) 111.0(15) 114.8(12) 0.6(6) 0.01(50) 123.7(22) 17.8(18)

Dihedral angles C(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–C(7) C(2)–C(3)–C(4)–C(5) C(5)–C(6)–C(7)–C(2) C(7)–C(2)–C(3)–C(4) C(6)–C(7)–C(2)–C(3) C(1)–C(2)–C(7)–N(8) C(3)–C(2)–C(7)–N(8) C(6)–C(7)–C(2)–C(1) C(2)–C(7)–N(8)–C(9) C(7)–C(2)–C(1)–C(9) C(2)–C(1)–C(9)–N(8) C(7)–N(8)–C(9)–C(1) C(1a)–C(1)–C(9)–N(8) C(1a)–C(1)–C(2)–C(7) C(1b)–C(1)–C(9)–N(8) C(1b)–C(1)–C(2)–C(7) C(8)–N(8)–C(7)–C(2) C(8)–N(8)–C(9)–C(1) C(10)–C(9)–C(1)–C(2) C(10)–C(9)–N(8)–C(7) O–C(9)–C(1)–C(2) O–C(9)–N(8)–C(7) C(11)=C(10)–C(9)–C(1) C(11)=C(10)–C(9)–N(8) C(17)–O–C(9)–C(1) C(17)–O–C(9)–N(8) C(9)–O–C(17)–C(12) C(9)–C(10)=C(11)–C(12) C(10)–C(9)–O–C(17) C(10)=C(11)–C(12)–C(17) O–C(9)–C(10)=C(11) O–C(17)–C(12)–C(11) O–C(17)–C(12)–C(13) C(11)–C(12)–C(17)–C(16) C(13)–C(12)–C(17)–C(16) C(13)–C(14)–C(15)–C(16) C(14)–C(15)–C(16)–C(17) C(14)–C(13)–C(12)–C(17) C(15)–C(16)–C(17)–C(12) C(15)–C(14)–C(13)–C(12) N–C(14)–C(15)–C(16) N–C(14)–C(13)–C(12) O(1)=N–C(14)–C(15) O(1)=N–C(14)–C(13) O(2)=N–C(14)–C(15) O(2)=N–C(14)–C(13)

τ [deg] a,b

-0.24(4) 0.40(6) 0.10(10) -0.42(10) -0.12(7) 0.30(7) -1.9 (4) -179.2(5) 177.7(5) -17.8(12) 18.3(11) -27.6(6) 28.5(15) 87.0(23) -98.1(14) -150.1(9) 139.2(15) -162.9(11) 173.8(8) -150.5(11) 153.6(11) 85.6(15) -83.3(11) -126.7(6) 115.5(6) 136.6(8) -113.7(9) -8.60(44) -0.1(2) 10.0(7) 2.5(3) -5.6(5) 1.81(14) -178.60(8) -179.41(8) 0.19(4) 0.80(5) -0.27(2) 0.33(2) -0.22(4) -0.83(5) 176.91(12) -176.95(10) 166.63(70) -17.21(48) 19.09(50) -164.74(72)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

855

856

10 Molecules with Ten or More Carbon Atoms

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Type of parameters was not specified. c Bond angle differences presented as A(i)–A(j)–A(k)–A(l) are defined as A(i)–A(j)–A(k) – A(i)–A(j)–A(l). b

The reversible isomerization of the title compound was studied by laser desorption-electron diffraction in order to determine the nascent product structures upon photo-excitation. The closed spiropyran form in the lowest excited triplet electronic state was produced at 843 K. The starting values of refined structural parameters were taken from B3LYP/6-311G(d,p) computation. Gahlmann A, Lee I-R, Zewail AH (2010) Direct structural determination of conformations of photoswitchable molecules by laser desorption-electron diffraction. Angew Chem / Angew Chem Int Ed 122 / 49 (37 / 37):66746677 / 6524-6527

942 CAS RN: 177569-26-5 MGD RN: 367029 TRED supported by DFT computations

(6Z)-6[(2Z)-2-(1,3-Dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)ethylidene]-4nitro-2,4-cyclohexadien-1-one

H 3C

CH3

C19H18N2O3 C1 O

Bonds C(1)–C(2) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(5)–C(6) C(6)–C(7) C(7)–N(8) N(8)–C(9) C(9)=C(10) C(10)–C(11) C(11)=C(12) C(12)–C(13) C(13)=C(14) C(14)–C(15) C(15)=C(16) C(16)–C(17) C(17)–O C(9)–C(1) C(2)–C(7) C(12)–C(17)

a,b

r [Å] 1.536(17) 1.417(17) 1.420(18) 1.418(16) 1.421(13) 1.412(14) 1.428(42) 1.381(34) 1.417(37) 1.431(34) 1.413(30) 1.451(26) 1.391(23) 1.445(19) 1.378(20) 1.474(14) 1.229(55) 1.542(20) 1.412(16) 1.481(32)

N CH3 N O

O

10 Molecules with Ten or More Carbon Atoms

C(1)–C(1a) C(1)–C(1b) N(8)–C(8) C(14)–N N=O(1) N=O(2)

1.534(31) 1.537(28) 1.469(8) 1.495(42) 1.215(46) 1.217(46)

Bond angles and bond angle difference c C(9)–C(1)–C(2) C(1)–C(2)–C(7) C(2)–C(7)–N(8) C(7)–N(8)–C(9) N(8)–C(9)–C(1) C(3)–C(2)–C(7)–C(1) C(6)–C(7)–C(2)–N(8) C(4)–C(3)–C(2) C(5)–C(4)–C(3) C(6)–C(5)–C(4) C(7)–C(6)–C(5) C(10)=C(9)–C(1)–N(8) C(9)=C(10)–C(11) C(10)–C(11)=C(12) C(11)=C(12)–C(17)–C(13) O–C(17)–C(12)–C(16) C(13)–C(12)–C(17) C(16)–C(17)–C(12) C(12)–C(13)=C(14) C(13)=C(14)–C(15) C(14)–C(15)=C(16) C(15)=C(16)–C(17) C(1a)–C(1)–C(2) C(1a)–C(1)–C(1b) C(1b)–C(1)–C(9) C(1a)–C(1)–C(9) C(1b)–C(1)–C(2) C(8)–N(8)–C(7)–C(9) N–C(14)=C(13)–C(15) O(1)=N–C(14) O(2)=N–C(14)–O(1)

θ [deg] a,b

Dihedral angles C(3)–C(4)–C(5)–C(6) C(4)–C(5)–C(6)–C(7) C(2)–C(3)–C(4)–C(5) C(5)–C(6)–C(7)–C(2) C(7)–C(2)–C(3)–C(4) C(6)–C(7)–C(2)–C(3) C(1)–C(2)–C(7)–N(8) C(3)–C(2)–C(7)–N(8) C(6)–C(7)–C(2)–C(1) C(2)–C(7)–N(8)–C(9) C(7)–C(2)–C(1)–C(9) C(2)–C(1)–C(9)–N(8) C(7)–N(8)–C(9)–C(1) C(1a)–C(1)–C(9)–N(8) C(1a)–C(1)–C(2)–C(7) C(1b)–C(1)–C(9)–N(8) C(1b)–C(1)–C(2)–C(7)

τ [deg] a,b

101.9(29) 108.9(43) 109.0(31) 111.2(27) 108.8(36) -11.4(15) -6.5(20) 119.0(19) 120.4(21) 121.2(9) 117.5(10) -9.0(39) 129.6(52) 126.3(43) 5.5(55) 2.2(21) 119.5(47) 116.0(34) 121.1(29) 120.7(63) 119.8(23) 122.9(28) 111.5(13) 110.3(9) 110.8(6) 110.2(9) 111.9(14) -3.9(12) 0.1(13) 117.8(18) -5.5(18)

0.21(15) 0.19(7) -0.12(7) -0.71(14) -0.38(22) 0.81(5) 0.49(20) -179.34(71) -179.36(62) -2.53(70) 1.43(55) -2.94(8) 3.47(29) 115.56(15) -116.12(24) -122.13(27) 119.87(17)

857

858

10 Molecules with Ten or More Carbon Atoms

C(8)–N(8)–C(7)–C(2) C(8)–N(8)–C(9)–C(1) C(10)=C(9)–C(1)–C(2) C(10)=C(9)–N(8)–C(7) C(11)–C(10)=C(9)–C(1) C(11)–C(10)=C(9)–N(8) C(9)=C(10)–C(11)–C(12) C(10)–C(11)=C(12)–C(13) C(10)–C(11)=C(12)–C(17) C(11)=C(12)–C(17)–C(16) C(11)=C(12)–C(13)=C(14) C(12)–C(13)=C(14)–C(15) C(12)–C(17)–C(16)=C(15) C(13)–C(12)–C(17)–C(16) C(13)–C(14)–C(15)=C(16) C(14)–C(15)–C(16)–C(17) C(14)=C(13)–C(12)–C(17) O–C(17)–C(12)–C(13) O–C(17)–C(16)–C(15) N–C(14)–C(15)–C(16) N–C(14)=C(13)–C(12) O(1)=N–C(14)–C(15) O(1)=N–C(14)=C(13) O(2)=N–C(14)–C(15) O(2)=N–C(14)=C(13)

173.98(44) -172.87(4) 177.42(2) -176.93(4) -169.90(3) 10.55(1) 178.97(2) -178.16(2) 1.46(1) -179.54(1) 179.74(2) -0.16(2) -0.21(2) 0.07(2) 0.03(1) 0.16(1) 0.11(1) 179.95(1) 179.91(1) 179.93(2) 179.93(0) -0.20(0) 179.71(0) 179.80(0) -0.30(0)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Type of parameters was not specified. c Bond angle differences presented as A(i)–A(j)–A(k)–A(l) are defined as A(i)–A(j)–A(k) – A(i)–A(j)–A(l). b

The reversible isomerization of 1',3'-dihydro-1',3',3'-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2'-[2H]indole] was studied by laser desorption-electron diffraction in order to determine the nascent product structures upon photo-excitation. The title molecule was major product after excitation at 266 nm. Only single conformer in the ground electronic state (S0) was produced at 1132 K. The N(8)–C(9)=C(10)–C(11), C(9)=C(10)–C(11)=C(12) and C(10)–C(11)=C(12)–C(17) chains possess the cis, s-trans and cis conformations, respectively. The starting values of refined structural parameters were taken from B3LYP/6-311G(d,p) computation. Gahlmann A, Lee I-R, Zewail AH (2010) Direct structural determination of conformations of photoswitchable molecules by laser desorption-electron diffraction. Angew Chem/Angew Chem Int Ed 122/49 (37/37):66746677/6524-6527

943 CAS RN: 5821-51-2 MGD RN: 145598 MW supported by ab initio calculations

Bonds C(1)–C(1ꞌ) C(1)–C(2) C(2)–C(3) C(3)–C(3ꞌ) C(3)–H

Dibenzo[ghi,mno]fluoranthene Corannulene C20H10 C5v

r0 [Å] a 1.417(4) 1.387(6) 1.441(3) 1.391(11) 1.101(14)

10 Molecules with Ten or More Carbon Atoms

Bond angles C(1ꞌ)–C(1)–C(2) C(1)–C(2)–C(3) C(2)–C(3)–C(3ꞌ) C(3)–C(3ꞌ)–H

θ0 [deg] a

Dihedral angles

τ0 [deg]

859

122.6(3) 114.5(3) 121.9(2) 118.45 c

θb

C(2)–C(3)–C(3ꞌ)–H

23.66 c 174.13 c

Reproduced with permission from the PCCP Owner Societies. a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Angle between the plane containing the C(3) atoms and the c inertial axis and the plane containing the C(2) atoms and the c inertial axis. c Assumed. b

The rotational spectra of corannulene were recorded in a supersonic jet by a chirped-pulse FTMW spectrometer in the frequency region between 2 and 8 GHz. The r0 structure was determined from the ground-state rotational constants of four isotopic species (main and three 13C).

Pérez C, Steber AL, Rijs AM, Temelso B, Shields GC, Lopez JC, Kisiel Z, Schnell M (2017) Corannulene and its complex with water: a tiny cup of water. Phys Chem Chem Phys 19(22):1421414223

944 CAS RN: 1233505-87-7 MGD RN: 541509 MW supported by ab initio calulations

Distance Rm b

Dibenzo[ghi,mno]fluoranthene – water (1/1) Corannulene – water (1/1) C20H12O C5v (see coment)

r0 [Å] a 2.640

O H

H

Reproduced with permission from the PCCP Owner Societies. a b

Uncertainty was not given in the original paper. Distance between the centers of mass of the monomer subunits.

The rotational spectrum of the complex of corannulene with water was recorded in a supersonic jet by a chirpedpulse FTMW spectrometer in the frequency region between 2 and 8 GHz.

860

10 Molecules with Ten or More Carbon Atoms

The partial r0 structure was determined from the ground-state rotational constants of the main isotopic species under the assumption that the structural parameters of the monomer subunits were not changed upon complexation. The complex has a bowl-like structure in which the water is located inside the bowl and freely rotates about its symmetry axis axis. Pérez C, Steber AL, Rijs AM, Temelso B, Shields GC, Lopez JC, Kisiel Z, Schnell M (2017) Corannulene and its complex with water: a tiny cup of water. Phys Chem Chem Phys 19(22):14214-14223

945 [2,2'-[1,2-Phenylenebis[(nitrilo-κN)methylidyne]]bis[phenolato]-κO]copper CAS RN: 42490-12-0 MGD RN: 366310 C20H14CuN2O2 GED combined with MS and C2v augmented by DFT computations

Distances Cu–N(2) Cu–O(4) N(2)–C(6) N(2)–C(12) O(4)–C(14) C(12)–C(16) C(14)–C(16) C(16)–C(18) C(18)–C(20) C(20)–C(24) C(22)–C(24) C(14)–C(22) C(6)–C(7) C(6)–C(8) C(8)–C(10) C(10)–C(11) C(8)–H C–H N...N N...O O...O

rh1[Å] a 1.960(20) b 1.913(17) b 1.414(15) b 1.312(15) 1.288(14) b 1.388(29) 1.449(4) 1.430(4) 1.378(4) 1.421(4) 1.380(4) 1.434(4) 1.423(4) b 1.408(4) 1.394(4) 1.402(4) 1.082(7) b 1.084(8) c 2.590(41) 2.806(20) 2.743(46)

Bond angles N–Cu–N O–Cu–O N–Cu–O Cu–N(2)–C(12) N(2)–C(12)–C(16) C(12)–C(16)–C(14) O(4)–C(14)–C(16) Cu–O(4)–C(14) C(14)–C(16)–C(18) C(16)–C(18)–C(20) C(18)–C(20)–C(24) C(20)–C(24)–C(22) C(14)–C(22)–C(24) Cu–N(2)–C(6) N(2)–C(6)–C(7) C(7)–C(6)–C(8) C(6)–C(8)–C(10)

θh1 [deg] a

82.7(18) b 91.6(21) b 92.9(9) 124.7(15) b 127.3(15) 122.5(12) 124.3(18) b 128.4(20) 119.4(3) b 121.8(3) 118.8(18) 121.3(27) 121.6(20) 115.5(12) 112.1(21) 119.2(6) b 120.7(6)

rg[Å] a 1.951(20) b 1.903(17) b 1.433(15) b 1.311(15) 1.295(14) b 1.401(29) 1.457(4) 1.428(4) 1.383(4) 1.428(4) 1.384(4) 1.431(4) 1.452(4) b 1.404(4) 1.401(4) 1.414(4) 1.085(7) b 1.088(8) c 2.578(41) 2.758(20) 2.778(46)

N

N Cu O

O

10 Molecules with Ten or More Carbon Atoms

C(8)–C(10)–C(11) N(3)–N(2)–C(6) N(2)–O(4)–C(14) H–C(8)–C(10)

861

120.1(24) 66.9(12) b 84.2(15) b 118.8(54) b

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Independent parameter, i.e. refined value. c Average value. The GED experiment was carried out at Teffusion cell of 545(5) and 552(5) K at the long and short camera distances, respectively. In the GED analysis, the differences between related parameters were assumed at the values from B3LYP/ECP(Cu),TZV(O,N,C,H) computation. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from computation at the level of theory as indicated above. The molecule was found to be planar. Tverdova NV, Pelevina ED, Giricheva NI, Girichev GV, Kuzmina NP, Kotova OV (2011) Molecular structure of N,N'-o-phenylene-bis(salicylideneaminato)copper(II) studied by gas-phase electron diffraction and quantumchemical calculations. Struct Chem 22 (2):441-448

946 [2,2ꞌ-[1,2-Phenylenebis[(nitrile-κN)methylidyne]]bis[phenolato-κO]]nickel CAS RN: 14406-71-4 MGD RN: 326521 C20H14N2NiO2 GED combined with MS and augmented by C2v DFT computations

Distances Ni–N(2)c Ni–O(4) c N(2)–C(6) c N(2)–C(12) O(4)–C(14) c C(12)–C(16) C(14)–C(16) C(16)–C(18) C(18)–C(20) C(20)–C(24) C(22)–C(24) C(14)–C(22) C(6)–C(7) c C(6)–C(8) C(8)–C(10) C(10)–C(11) C(8)–H c C–H N...N N...O O...O

rh1 [Å] a,b 1.876(19) 1.847(17) 1.428(11) 1.327(11) 1.286(10) 1.404(27) 1.441(2) 1.427(2) 1.376(2) 1.420(2) 1.378(2) 1.431(2) 1.413(2) 1.404(2) 1.394(2) 1.401(2) 1.103(10) 1.099(10) 2.563(24) 2.736(18) 2.497(28)

Bond angles

θh1 [deg] d

rg [Å] a 1.880(19) 1.847(17) 1.426(11) 1.327(11) 1.289(10) 1.410(27) 1.446(2) 1.428(2) 1.380(2) 1.425(2) 1.381(2) 1.431(2) 1.403(2) 1.405(2) 1.396(2) 1.404(2) 1.108(10) 1.104(10) 2.520(24) 2.719(18) 2.593(28)

N

N Ni O

O

862

N–Ni–N c O–Ni–O c N–Ni–O Ni–N(2)–C(12) c N(2)–C(12)–C(16) C(12)–C(16)–C(14) O(4)–C(14)–C(16) c Ni–O(4)–C(14) C(14)–C(16)–C(18) c C(16)–C(18)–C(20) C(18)–C(20)–C(24) C(20)–C(24)–C(22) C(14)–C(22)–C(24) Ni–N(2)–C(6) N(2)–C(6)–C(7) C(7)–C(6)–C(8) c C(6)–C(8)–C(10) C(8)–C(10)–C(11) N(3)–N(2)–C(6) c N(2)–O(4)–C(14) c H–C(8)–C(10) c

10 Molecules with Ten or More Carbon Atoms

86.2(10) 84.7(13) 94.6(4) 125.8(12) 125.4(14) 121.4(8) 124.5(13) 128.4(12) 119.9(3) 121.7(3) 117.7(14) 123.3(20) 119.8(15) 113.9(8) 112.4(10) 119.6(4) 120.2(4) 120.2(19) 67.0(7) 85.3(10) 121.7(26)

Copyright 2011 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Differences between chemically-equivalent parameters were fixed at the values from computation at the level of theory as indicated below. c Independent parameter. d Parenthesized uncertainties in units of the last significant digit are 3σ values. The combined GED/MS experiment was carried out at Teffusion cell = 549(6) K. The title molecule was assumed to have planar phenyl rings and C2v overall symmetry. The torsional angles τ[C(6)–N(2)…N(3)–Ni], τ[C(12)–N(2)–Ni…C(6)] and τ[C(8)–C(6)–C(7)–N(3)] were determined to be close to 180°. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from DFT computation (B3LYP/TZV(O,N,C,H),ECP(Ni)). Tverdova NV, Pelevina ED, Giricheva NI, Girichev GV, Kuzmina NP, Kotova OV (2012) Molecular structures of 3d metal complexes with various Schiff bases studied by gas-phase electron diffraction and quantum-chemical calculations. J Mol Struct 1012:151-161.

[[2,2'-[1,2-Phenylenebis[(nitrilo-κN)methylidyne]bis[phenolato-κO]]zinc 947 CAS RN: 21380-07-4 MGD RN: 213970 C20H14N2O2Zn GED combined with MS and augmented Cs by DFT computations

Distances Zn(1)–N(2) Zn(1)–O(4) N(2)–C(6) N(2)=C(12) O(4)–C(14) C(12)–C(16)

rh1 [Å] a 2.072(12) 1.926(7) 1.407(12) 1.307(12) b 1.297(17) 1.403(23) b

N

N Zn O

O

10 Molecules with Ten or More Carbon Atoms

C(16)–C(14) C(16)–C(18) C(18)–C(20) C(20)–C(24) C(22)–C(24) C(14)–C(22) C(6)–C(7) C(6)–C(8) C(8)–C(10) C(10)–C(11) C(12)–H C–H N(2)...N(3) N(2)…O(4) O(4)...O(5)

1.445(4) 1.425(4) b 1.375(3) b 1.414(4) b 1.377(3) b 1.426(4) b 1.423(4) b 1.404(3) b 1.390(3) b 1.397(4) b 1.094(7) 1.085(7) c 2.590(3) b 2.839(28) b 2.991(42) b

Bond angles N(2)–Zn–N(3) O(5)–Zn–O(4) N(2)–Zn–O(4) Zn–N(2)=C(12) N(2)=C(12)–C(16) C(12)–C(16)–C(14) O(4)–C(14)–C(16) Zn–O(4)–C(14) C(14)–C(16)–C(18) C(16)–C(18)–C(20) C(18)–C(20)–C(24) C(20)–C(24)–C(22) C(14)–C(22)–C(24) Zn–N(2)–C(6) N(2)–C(6)–C(7) C(7)–C(6)–C(8) C(6)–C(8)–C(10) C(8)–C(10)–C(11) N(3)…N(2)–C(6) N(2)–O(4)–C(14) H–C(8)–C(10)

θh1 [deg] d

Dihedral angles C(6)–N(2)…N(3)–Zn C(8)–C(6)–C(7)–N(3) C(12)=N(2)–Zn…C(6)

τh1 [deg] d

863

77.4(14) 101.9(25) 90.4(13) b 125.2(12) 125.7(15) b 123.9(10) b 124.9(15) 129.7(18) b 119.3(4) 122.1(4) b 118.5(19) b 121.5(28) b 121.6(20) b 117.5(16) b 112.8(29) b 119.3(3) 121.2(3) b 118.9(15) b 66.4(19) 83.0(14) 118.9(42)

173.8(244) 177.7(264) 180.8(330)

Copyright 2010 with permission from Elsevier.

a Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Dependent parameter. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values.

The combined GED/MS experiment was carried out at the temperature of 626(5) K. Dimeric form of the title molecule or any volatile impurities of the sample were not detected in the vapor. The phenyl rings were assumed to be planar. The central ZnN2O2 unit was found to be planar. The overall ligand conformation was determined to be almost planar with small distortion towards an umbrella-shape.

864

10 Molecules with Ten or More Carbon Atoms

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from DFT computation (B3LYP/ECP(Zn),TZV(O,C,N,H)). Girichev GV, Giricheva NI, Tverdova NV, Pelevina ED, Kuzmima NP, Kotova OV (2010) Molecular structure of N,N'-o-phenylene-bis(salicylideneaminato)zinc(II), Zn(saloph), according to gas-phase electron diffraction and quantum-chemical calculations. J Mol Struct 978 (1-3):178-186

948 CAS RN: 2129100-39-4 MGD RN: 573360 GED supplemented by DFT computations

Tris[2,3,5,6-tetrafluoro-4-(trifluoromethyl)phenyl]borane C21BF21 C3

CF3

Bonds B–C(1) C(1)–C(2) C(1)–C(6) C(2)–C(3) C(5)–C(6) C(3)–C(4) C(4)–C(5) C(2)–F C(3)–F C(5)–F C(6)–F C(4)–C(7) C(7)–F(1) C(7)–F(2) C(7)–F(3)

re [Å] a,b 1.557(6) 1.395(2) 1 1.398(2) 1 1.392(2) 1 1.386(2) 1 1.394(2) 1 1.397(2) 1 1.324(1) 2 1.316(1) 2 1.317(1) 2 1.324(1) 2 1.542(5) 1.320(1) 2 1.329(1) 2 1.329(1) 2

Bond angles B–C(1)–C(2) B–C(1)–C(6) C(1)–C(2)–C(3) C(1)–C(6)–C(5) C(1)–C(2)–F C(1)–C(6)–F C(2)–C(3)–F C(6)–C(5)–F C(4)–C(7)–F(1) F(1)–C(7)–F(2) C(4)–C(7)–F(2)

θe [deg] a,b

Dihedral angle C(1')–B–C(1)–C(2)

τe [deg] a

F

F

F

F

F

F B

F

F3C

F F

F

F

CF3 F

120.7(1) 3 122.7(1) 3 124.1(2) 4 123.5(2) 4 123.1(2) 5 120.8(2) 5 122.1(2) 5 120.8(2) 5 112.2(2) 6 107.3(3) 109.8(2) 6

56.8(10)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties in units of the last significant digit are 3σ values. Parameters with equal superscripts were refined in one group; differences between parameters in each group were fixed at the values from B3LYP/6-311G(2df) computations. b

The GED experiment was carried out at Tnozzle = 436 K.

10 Molecules with Ten or More Carbon Atoms

865

Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated with quadratic and cubic force constants from computation at the level of theory as indicated above by taking into account nonlinear kinematic effects. Körte LA, Schwabedissen J, Soffner M, Blomeyer S, Reuter CG, Vishnevskiy YV, Neumann B, Stammler HG, Mitzel NW (2017) Tris(perfluorotolyl)borane - a boron Lewis superacid. Angew Chem Int Ed / Angew Chem 56 /129 (29 /29):8578-8582 /8701-8705

949 CAS RN: 119796-31-5 MGD RN: 540943 GED combined with MS and augmented by DFT computations

1,8-Bis[2-(trimethylsilyl)ethynyl]anthracene C24H26Si2 (see comment) H 3C H3C

Si

Bonds C(10)–C(10a) C(4a)–C(9a) C(1)–C(2) C(1)–C(11) C(11)≡C(12) C(12)–Si Si–C(13) C(9)–C(9a) C(4)–C(4a) C(3)–C(4) C(2)–C(3) C(1)–C(9a) C–H (anthracene) C–H (methyl)

rh1 [Å] a 1.396(3) b 1.436(3) 1.374(3) 1.420(6) b 1.210(5) b 1.830(4) b 1.862(4) 1.398(3) 1.431(3) 1.362(3) 1.421(3) 1.448(3) 1.081(7) b,c 1.089(5) b,c

Bond angles C(8a)–C(9)–C(9a) C(9a)–C(1)–C(2) C(4a)–C(4)–C(3) C(4a)–C(10)–C(10a) C(9a)–C(4a)–C(4) C(9a)–C(1)–C(11) C(12)–Si–C(13) C(1)–C(11)≡C(12) C(11)≡C(12)–Si

θh1 [deg] d

Dihedral angle C(13)–Si–C(12)...C(2)

τh1 [deg] d

119.8(7) 117.3(7) 120.2(3) 121.3(3)b 119.5(4) 120.7(3) 109.1(13) b 178.2(60) b 178.2(60) b 7(40) b

Reproduced with permission from the PCCP Owner Societies.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Independent parameter. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values.

CH3

H 3C H 3C

Si

C

C

C

C

CH3

866

10 Molecules with Ten or More Carbon Atoms

Different DFT methods, namely B3LYP and B3LYP-D2(D3) (with accounting for dispersion interactions), predicted two different equilibrium structures, characterized by different location of the –C–C≡C–Si(CH3)3 units: bent away from each other (C2 point-group symmetry) and unidirectionally bent (C1 symmetry). The barrier to internal rotation of the trimethylsilyl group, predicted to be 1.9 kJ mol-1 (B3LYP/6-31G*), is lower than the thermal energy of 3.4 kJ mol-1 at the temperature of the experiments (Teffusion cell = 408(12) K). Due to nonhindered rotation and bending of the substituent groups, these structures could not be distinguished in the GED analysis. Anharmonic vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were derived by MD simulations. Otlyotov AA, Lamm JH, Blomeyer S, Mitzel NW, Rybkin VV, Zhabanov YA, Tverdova NV, Giricheva NI, Girichev GV (2017) Gas-phase structure of 1,8-bis[(trimethylsilyl)ethynyl]anthracene: cog-wheel-type vs. independent internal rotation and influence of dispersion interactions. Phys Chem Chem Phys 19 (20):1309313100

950 CAS RN: 51777-38-9 MGD RN: 384573 GED augmented by DFT computations

Octakis[(trimethylsilyl)oxy]pentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane C24H72O20Si16 D4 (I) D2 (II) H 3C H 3C H 3C H 3C

CH3

CH3

Si

Si O

Si

H 3C H 3C H 3C H 3C H 3C

Bonds Si–O Si–C C–H Si(1)–O(3) Si(1)–O(16) Si(1)–O(10) Si(1)–O(24) Si(33)–O(24) Si(1)–O(3) Si(2)–O(3) Si(1)–O(10) Si(9)–O(10) Si(1)–O(16) Si(15)–O(16) Si(1)–O(24) Si(33)–O(24) Si(2)–O(21) Si(34)–O(21) Bond angles Si–C–H

I 1.6138(8) b,c 1.863(2) b,c 1.100(5) b,d 1.613(2) e 1.610(2) e 1.610(2) e 1.588(4) e 1.650(4) e

I 111.5(9) b,d

θe [deg] a

II 111.5(9) b,d

Si

O

Si

O Si

O Si O O

H 3C O

O

Si O O

Si O

O

O

CH3 CH3

Si

Si O

O

CH3 Si

Si

CH3

O

Si

Si

CH3

CH3

re [Å] a II 1.6138(8) b,c 1.863(2) b,c 1.100(5) b,d

1.611(2) e 1.613(2) e 1.614(3) e 1.610(3) e 1.609(2) e 1.611(2) e 1.588(4) e 1.649(4) e 1.587(4) e 1.648(4) e

O

O

CH3

O O

Si

CH3

CH3

CH3

CH3 CH3

10 Molecules with Ten or More Carbon Atoms

Si(1)–O(3)–Si(2) top Si(1)–O(24)–Si(33) ligand Si(1)–O(10)–Si(9) side Si(1)–O(3)–Si(2) top1 Si(1)–O(16)–Si(15) top2 Si(2)–O(21)–Si(34) ligand down Si(2)–O(24)–Si(33) ligand up O–Si–C C(2)–Si(33)–C(3) C(1)–Si(33)–C(2) C(2)–Si(33)–C(3) down1 C(1)–Si(33)–C(2) down2 C(85)–Si(34)–C(87) up1 C(86)–Si(34)–C(87) up2 X…Si(1)–O(24) g X…Si(2)–O(21) g up X…Si(1)–O(24) g down Si(1)…Si(2)…Si(6) Si(1)–O(10)–Si(9) side Dihedral angles X…Si(1)–O(24)–Si(33) g X…Si(2)–O(21)–Si(34) g down X…Si(1)–O(24)–Si(33) g up C(2)–Si(33)–O(24)–Si(1) C(2)–Si(33)–O(24)–Si(1) up C(87)–Si(34)–O(21)–Si(2) down O(3)–Si(1)…Si(2)…X g O(16)–Si(1)…Si(15)…X g

147.3(9) d 153.5(9) d 150.5(11) d

108.6(9) b,c,f 110.9(11) d 111.0(11) d

149.7(11) d

I -87.3(30) d -150.8(20) d -134.7(31) d

867

147.6(10) d 148.5(9) d 152.0(10) d 151.6(9) d 108.6(9) b,c,f 110.9(11) d 110.7(11) d 111.1(11) d 110.8(11) d 140.4(10) 143.1(8) 94.3(4) 148.5(9) d

τe [deg] a II

13.0(29) d 180.0(31) d 81.2(83) d 98.6(67) d 125.9(30) d 142.4(31) d

Reprinted with permission. Copyright 2011 American Chemical Society.

a

Parenthesized uncertainties in units of the last significant digit are the estimated standard deviations. Average value. c Assumed to be equal in both conformers. d Restrained to the value from B3LYP/6-311G* computation. e Dependent parameter. f Differences between the O–Si–C angles in each conformer were assumed at the value from computation as indicated above. g X is the point at the center of the square face formed by four Si atoms. b

Two conformers, I and II, with D4 and D2 symmetry, respectively, were predicted by B3LYP/6-311G* computations. The energy difference was estimated to be 1.2 kJ mol-1, the conformer I being more stable than the conformer II. The direction of the bend of the exocyclic OSiMe3 groups qualitatively describes the orientation of each conformer: the OSiMe3 groups on each of two opposite faces of the cage, being all bent in the same sense, define the 4-fold rotation symmetry for the D4 conformer, while for the D2 conformer, the OSiMe3 groups alternate in being bent “up” or “down” relative to these two faces. The GED experiment was carried out at Tnozzle of 230 and 250 K at the long and short nozzle-to-film distances, respectively. Local C3v symmetry, no tilt and staggered conformation relative to the Si–C rotational axis were assumed for the methyl groups. The best agreement between the experimental intensities and their theoretical counterpart was +2

obtained for 73( −3 )% of D4 conformer. Anharmonic vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were derived by semiempirical MD simulations with the PM6 geometry optimization.

868

10 Molecules with Ten or More Carbon Atoms

I

II Wann DA, Dickson CN, Lickiss PD, Robertson HE, Rankin DWH (2011) The gas-phase equilibrium structures of Si8O12(OSiMe3)8 and Si8O12(CHCH2)8. Inorg Chem 50 (7):2988-2994

10 Molecules with Ten or More Carbon Atoms

951 CAS RN: 2139349-54-3 MGD RN: 548500 GED supplemented by MW and augmented by QC computations

Bonds C(2)–C(3) C–C (oxadiamantyl) C–O Dihedral angle

ϕc

869

8,8'-Dioxa-1,1'-bis(pentacyclo[7.3.1.14,12.02,7.06,11]tetradecane) C26H34O2 C2 (I) C2 (II)

re [Å] a I II 1.632(5) b 1.633(5) b b 1.534(1) 1.533(1) b b 1.417(3) 1.419(3) b

I 86.5(14)

O

O

τe [deg] a

II -93.2(22)

Reprinted with permission. Copyright 2017 American Chemical Society.

I

II

a

Parenthesized uncertainties in units of the last significant digit are 1σ values. Average value. c Dihedral angle describing the relative orientation of the two oxadiamantyl fragments, C(1)–C(2)–C(3)–C(4). b

Two lowest energy conformers of the title compound, predicted by several DFT computations with various functionals (also including dispersion energy), were found to be present in the gas phase by combined analysis of the GED data (Tnozzle = 583 K) and rotational constants. The ratio of the conformers, differing in the values of the torsional angle around the central C–C bond, was determined to be I : II = 49(14) : 51(14) (in %). Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, and rovibrational corrections to the ground-state rotational constants, ∆Be = Be − B0, were calculated with quadratic and cubic force constants from B3LYP-D3/6-311G(d,p) and B97-D3/SVP computations by taking into account non-linear kinematic effects. The central C−C bond was found to be markedly long. Fokin AA, Zhuk TS, Blomeyer S, Perez C, Chernish LV, Pashenko AE, Antony J, Vishnevskiy YV, Berger RJF, Grimme S, Logemann C, Schnell M, Mitzel NW, Schreiner PR (2017) Intramolecular London dispersion interaction effects on gas-phase and solid-state structures of diamondoid dimers. J Am Chem Soc 139 (46):16696-16707

870

10 Molecules with Ten or More Carbon Atoms

952 [2,3,7,8,12,13,17,18-Octamethyl-21H,23H-porphinato-κN21,κN22,κN23,κN24]copper CAS RN: 15079-58-0 MGD RN: 367380 C28H28CuN4 GED combined with MS and D4h augmented by DFT computations H 3C CH3

Bonds Cu–N(1) N(1)–C(11) C(11)–C(17) C(11)–C(12) C(12)–C(13) C(12)–C(15) C–C C(17)–H C(15)–H

rh1 [Å] a 2.013(5) 1.378(4) 1.390(3) 1.455(3) 1.372(3) 1.503(3) 1.438 b 1.115(5) 1.126(5) b

Bond angles C(11)–N(1)–C(14) N(1)–C(11)–C(12) C(11)–C(12)–C(13) C(11)–C(17)–C(24) C(12)–C(13)–C(16) Cu–N(1)–C(11)

θh1 [deg] c

Dihedral angles C(11)–N(1)…N(3)–C(31) C(15)–C(12)–C(13)–C(14)

τh1 [deg] c

H 3C

CH3 N

N Cu

N

N

H 3C

CH3

H 3C

CH3

105.7(2) 110.8(2) 106.4(2) 125.5(3) 128.1(4) 127.1(1)

0.0 175(6)

Copyright 2010 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Average values. c Parenthesized uncertainties in units of the last significant digit are 3σ values.

The GED experiment was carried out at Teffusion cell=674(10) K. The best fit to experimental intensities was obtained for a formally planar structure of the heavy-atom skeleton. The methyl groups were found to possess the eclipsed configuration with respect to the C=C bond opposite to the nitrogen atom in the pyrrole ring. It was shown that alkyl substituents in pyrrole ring give a minor effect on the geometry of the coordination centre. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1 were calculated using harmonic force field from B3LYP/6-31G* computation. According to prediction of DFT computations at the level of theory as indicated above, the title molecule has planar skeleton. This work is a first molecular structure study of porphyrine metal complexes in the gas phase.

10 Molecules with Ten or More Carbon Atoms

871

Girichev GV, Giricheva NI, Golubchikov OA, Mimenkov YV, Semeikin AS, Shlykov SA (2010) Octamethylporphyrin copper, C28H28N4Cu - A first experimental structure determination of porphyrins in gas phase. J Mol Struct 978 (1-3):163-169

[2,3,7,8,12,13,17,18-Octamethyl-21H,23H-porphinato-κN21,κN22,κN23,κN24]tin 953 CAS RN: 1383808-53-4 MGD RN: 213422 C28H28N4Sn GED combined with MS and augmented by C4v DFT computations H 3C CH3

Distances C–H Sn–N(1) Sn…X d N(1)–C(1) C(1)–C(15) C(1)–C(2) C(2)–C(3) C(3)–C(6) N(1)…N(2)

rh1 [Å] a 1.097(6) b 2.301(9) c 1.025(30) 1.360(8) c 1.395(4) c,e 1.453(4) c,e 1.399(8) c,e 1.498(4) c,e 2.914(14)

Bond angles C(1)–N(1)–C(4) C(3)–C(4)–N(1) C(1)–C(2)–C(3) C(1)–C(15)–C(10) C(6)–C(3)–C(4) C(1)–N(1)–Sn N(1)–Sn–N(3) H–C(6)–C(3)

θh1 [deg] f

Dihedral angles C(1)...C(3)–C(2)...C(6) C(2)–C(3)–C(4)–N(1) C(4)–N(1)...N(3)–C(12) C(4)–N(1)–Sn–N(3) C(3)–C(4)–N(1)–Sn C(15)–C(1)...C(10)...Sn C(6)–C(3)–C(4)–N(1)

τh1 [deg] f

ra [Å] a 1.096(5) b 2.299(9) 1.358(8) 1.397(4) 1.454(4) 1.400(8) 1.498(4)

H3C

CH3 N

N Sn

N

N

H 3C

CH3

H 3C

CH3

107.3(6) 110.5(4) c 105.8(3) 126.7(9) 126.6(7) c 124.2(6) c 127.1(10) c 111.1(20) c

176.2(62) 2.2(27) 168.5(35) 103.2(19) c 153.8(25) c 157.2(51) c 178.4(46) c

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Average value. c Independent parameter. d Height of the SnN4 square pyramid. e Differences between the C−C bond lengths were assumed at the values from calculation at the level of theory as indicated below. f Parenthesized uncertainties in units of the last significant digit are 2.5σ values. The GED experiment was carried out at Teffusion cell = 706(10) K.

872

10 Molecules with Ten or More Carbon Atoms

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/ECP(Sn),cc-pVTZ(C,N,H) calculation. Girichev GV, Giricheva NI, Koifman OI, Minenkov YV, Pogonin AE, Semeikin AS, Shlykov SA (2012) Molecular structure and bonding in octamethylporphyrin tin(II), SnN4C28H28. Dalton Trans 41 (25):7550-7558

954 CAS RN: 344583-45-5 MGD RN: 548676 GED augmented by QC computations

Bond C(1)–C(1') Dihedral angle

ϕ

b

Hexadecahydro-1,1'(2H,2'H)-bi-3,5,1,7-[1,2,3,4]butanetetraylnaphthalene 1,1'-Bis(pentacyclo[7.3.1.14,12.02,7.06,11]tetradecane) C28H38 C2

re [Å] a 1.630(5)

τe [deg] a 86.5(22)

Reprinted with permission. Copyright 2017 American Chemical Society.

a b

Parenthesized uncertainties in units of the last significant digit are 1σ values. Dihedral angle describing the relative orientation of the two diamantyl fragments, C(2)–C(1)–C(1ʹ)–C(2ʹ).

Following to predictions of ab initio (MP2 and HF) and DFT (with various functionals also including dispersion energy) computations, the model of a single conformer with C2 point-group symmetry was used in the GED analysis. Vibrational corrections to the experimental internuclear distances, ∆re = ra − re, were calculated from the B97D3/SVP quadratic and cubic force fields taking into account non-linear kinematic effects. The central C−C bond was found to be markedly long. Fokin AA, Zhuk TS, Blomeyer S, Perez C, Chernish LV, Pashenko AE, Antony J, Vishnevskiy YV, Berger RJF, Grimme S, Logemann C, Schnell M, Mitzel NW, Schreiner PR (2017) Intramolecular London dispersion interaction effects on gas-phase and solid-state structures of diamondoid dimers. J Am Chem Soc 139 (46):16696-16707 955 CAS RN: 358335-01-0 MGD RN: 343449

7,10:19,22:31,34-Triepithio-5,36:12,17:24,29-triiminotribenzo[f,p,z][1,2,4,9,11,12,14,19,21,22,24,29]dodecaazacyclotriacontine C30H15N15S3

10 Molecules with Ten or More Carbon Atoms

GED combined with MS and augmented by DFT computations

Bonds N–C(1) C(1)–N(5) N(5)–C(7) C(7)–N(6) N(6)–N(6ʹ) C(7)–S C(1)–C(2) C(2)–C(2ʹ) C(2)–C(3) C(3)–C(4) C(4)–C(4ʹ)

rh1 [Å] a 1.400(17) 1.283(12) 1.368(17) 1.310(12) 1.338(20) 1.739(5) 1.491(18) 1.416(45) 1.368(18) 1.407(18) 1.382(45)

Bond angles C(1)–N(5)–C(7) N(5)–C(7)–N(6) N(5)–C(7)–S C(1)–C(2)–C(2') C(1)–C(2)–C(3) C(2)–C(3)–C(4) c C(3)–C(4)–C(4ʹ) c

θh1 [deg] b

873

D3h

122.9(15) 127.3(9) 119.3(8) 107.3(15) 130.7(20) 116.1(18) 121.9(14)

Copyright 2013 World Scientific Publishing Company. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.001r. b Parenthesized uncertainties in units of the last significant digit are 3σ values. c Definition of these angles seems to be misprinted in the original paper.

The title compound was evaporated at 797(5) K.

874

10 Molecules with Ten or More Carbon Atoms

Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Zhabanov YA, Zakharov AV, Shlykov SA, Trukhina ON, Danilova EA, Koifman OI, Islyaikin MK (2013) Molecular structure and tautomers of [30]trithia-2,3,5,10,12,13,15,20,22,23,25,30-dodecaazahexaphyrin. J Porphyrins Phthalocyanines 17 (3):220-228

956 CAS RN: 78053-62-0 MGD RN: 466820 GED combined with MS and augmented by DFT computations

Bonds C(1)–C(2) C(1)–C(9a) C(1)–C(11) C(4)–C(4a) C(9)–H C(10)–C(4a) C(11)≡C(12) C(12)–C(13) C(13)–C(18) C–C

re [Å] a 1.378(6) 1.443(6) 1.422(7) b 1.422(6) 1.085(5) b 1.393(6) b 1.205(8) b 1.424(7) 1.411(6) b 1.409(6) c

Bond angles C(1)–C(11)–C(12) C(4a)–C(10)–C(10a) C(9a)–C(4a)–C(4) C(11)≡C(12)–C(13) C(12)–C(13)–C(18)

θe [deg] d

Dihedral angle C(18)–C(13)…C(1)–C(2)

τe [deg] d

1,8-Bis(2-phenylethynyl)anthracene C30H18 C2 C

C

C

C

179.8(33) 121.8(7) b 119.2(4) b 178.9(33) 120.4(13) b

24.4(180) b

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Independent parameter. c Average value in the anthracene fragment. d Parenthesized uncertainties in units of the last significant digit are 3σ values. Five conformers, characterized by different orientations of the phenylethynyl fragments, were predicted by DFT computation at the B3LYP level of theory (with and without correction for dispersive interaction) in conjunction with cc-pVTZ basis set. Depending on the method of calculations, the lowest-energy conformer was predicted to have either C2 point-group symmetry, i.e. with co-directional rotated phenylethynyl groups, or Cs symmetry, i.e. with one phenyl group being coplanar with the anthracene plane and the other one perpendicular to this plane. In the GED analysis (Tnozzle = 498 K), the C2 conformer was found to be present as a single conformer. Anharmonic vibrational corrections to the experimental internuclear distances, ∆re = ra – re, were estimated by MD simulations.

10 Molecules with Ten or More Carbon Atoms

875

Lamm JH, Horstmann J, Stammler HG, Mitzel NW, Zhabanov YA, Tverdova NV, Otlyotov AA, Giricheva NI, Girichev GV (2015) 1,8-Bis(phenylethynyl)anthracene - gas and solid phase structures. Org Biomol Chem 13 (33):8893-8905

957 CAS RN: 147-14-8 MGD RN: 124610 GED combined with MS and augmented by DFT computations

[29H,31H-Phthalocyaninato-κN29,κN30,κN31,κN32]copper Copper phthalocyanine C32H16CuN8 D4h

Distances Cu–N(1) N(1)–C(1) C(1)–N(2) Cu…N(2) C(1)–C(2) C(2)–C(7) C(2)–C(3) C(3)–C(4) C(4)–C(5) C(3)–H

rh1[Å] a 1.949(5) 1.381(5) 1.325(5) 3.385(9) 1.459(5) 1.417(11) 1.399(4) b 1.397(4) b 1.429(18) 1.091(9) c

rg[Å] a 1.947(5) 1.381(5) 1.327(5)

Bond angles N(1)–Cu–N(4) N(1)–C(1)–N(2) C(8)–N(3)–C(9) C(1)–N(1)–C(8) N(1)–C(1)–C(2) C(1)–C(2)–C(7) C(2)–C(7)–C(6) C(2)–C(3)–C(4) C(3)–C(4)–C(5) C(2)–C(3)–H Cu–N(1)–C(1)

θh1 [deg] d

θg [deg] d

e

90.0 128.2(5) 121.9(7) 108.3(5) 109.5(5) 106.4(4) 121.3(2) 117.7(2) 121.1(4) 123.2(44)

Reproduced with permission of SNCSC [a].

N

N

1.460(5) N

1.399(4) 1.092(9) c

90.0 e 109.5(5) 109.5(5) 121.3(2)

123.2(44) 125.9(2)

N

N

Cu

N

N

N

876

10 Molecules with Ten or More Carbon Atoms

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Difference between the C(2)–C(3) and C(3)–C(4) distances was assumed at the value from UB3LYP computation. c Average value. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Assumed. Molecular structure from Ref. [b] was reinvestigated. The GED experiment was carried out at Teffusion cell = 770(5) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from UB3LYP/6-31G* computation. a. Tverdova NV, Girichev GV, Giricheva NI, Pimenov OA (2011) Accurate molecular structure of copper phthalocyanine (CuN8C32H16) determined by gas-phase electron diffraction and quantum-chemical calculations. Struct Chem 22 (2):319-325 b. Mastryukov V, Ruan C-Y, Fink M (2000) The molecular structure of copper- and nickel-phthalocyanine as determined by gas-phase electron diffraction and ab initio/DFT computations. J Mol Struct 556:225-237 [29H,31H-Phthalocyaninato-κN29,κN30,κN31,κN32]nickel Nickel phthalocyanine C32H16N8Ni D4h

958 CAS RN: 14055-02-8 MGD RN: 133514 GED combined with MS and augmented by DFT computations

Distances Ni–N(1) N(1)–C(1) C(1)–N(2) Ni...N(2) b C(1)–C(2) C(2)–C(7) b C(2)–C(3) C(3)–C(4) b C(4)–C(5) b C(3)–H

rh1 [Å] a 1.913(5) 1.385(4) 1.327(5) 3.385(8) 1.462(6) 1.399(3) 1.399(3) 1.395(3) 1.399(3) 1.103(10)

Bond angles N(1)–Ni–N(4) b Ni–N(1)–C(1) N(1)–C(1)–N(2) b C(8)–N(3)–C(9) b C(1)–N(1)–C(8) b N(1)–C(1)–C(2) C(1)–C(2)–C(7) b C(2)–C(7)–C(6) C(2)–C(3)–C(4) b C(3)–C(4)–C(5) b N(2)–C(1)–C(2) b C(2)–C(3)–H

θh1 [deg] c

rg [Å] a 1.905(5) 1.382(4) 1.332(5) 3.363(8) 1.463(6) 1.403(3) 1.398(3) 1.396(3) 1.400(3) 1.102(10)

90.0 126.6(2) 128.4(4) 120.1(5) 106.8(4) 110.0(4) 106.0(5) 121.2(1) d 117.4(1) 121.4(4) 121.2(4) 119.6(34) e

Copyright 2012 with permission from Elsevier [a].

N

N

N

N

N

Ni

N

N

N

10 Molecules with Ten or More Carbon Atoms

877

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Dependent parameter. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Difference between the C(2)–C(7)–C(6) and C(7)–C(6)–C(5) bond angles was assumed at the value from computation at the level of theory as indicated below. e Difference between the C(2)–C(3)–H and C(3)–C(4)–H bond angles was assumed at the value from computation at the level of theory as indicated below. Reinvestigation of molecular structure from Ref. [b]. The GED experiment was carried out at Teffusion cell = 776(5) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/ECP(Ni),cc-pVTZ(N,C,H) computation. a. Tverdova NV, Pimenov OA, Girichev GV, Shlykov SA, Giricheva NI, Mayzlish VE, Koifman OI (2012) Accurate molecular structure of nickel phthalocyanine (NiN8C32H16): Gas-phase electron diffraction and quantum-chemical calculations. J Mol Struct 1023:227-233 b. Mastryukov V, Ruan C-Y, Fink M, Wang Z, Pachter R (2000) The molecular structure of copper- and nickelphthalocyanine as determined by gas-phase electron diffraction and ab initio/DFT computations. J Mol Struct 556:225-337

959 CAS RN: 26201-32-1 MGD RN: 363264 GED combined with MS and augmented by DFT computations

Oxo[29H,31H-phthalocyaninato-κN29,κN30,κN31,κN32]titanium Titanyl phthalocyanine C32H16N8OTi C4v

Distances Ti=O Ti–N N(1)–C(1ʹ) N(2ʹ)–C(1ʹ) C(1ʹ)–C(2ʹ) C(2ʹ)–C(2) C(2ʹ)–C(3ʹ) C(3ʹ)–C(4ʹ) C(4ʹ)–C(4) C(3ʹ)–H C(4ʹ)–H N(1)...N(1ʹ) N(1)...N Ti…z(N) d

rh1[Å] a,b 1.595(9) 2.090(5) 1.383(7) 1.325(8) c 1.449(8) 1.400(21) c 1.407(9) 1 1.404(9) 1 1.388(24) c 1.063(5) 2 1.064(5) 2 2.813(9) 3.979(13) 0.641

Bond angles O=Ti–N Ti–N–C(1ʹ) N(1)–C(1ʹ)–N(2ʹ) N(1)–C(1ʹ)–C(2ʹ) C(1ʹ)–C(2ʹ)–C(2) C(1ʹ)–C(2ʹ)–C(3ʹ) C(2ʹ)–C(3ʹ)–C(4ʹ) C(3ʹ)–C(4ʹ)–C(4) C(2ʹ)–C(3ʹ)–H C(3ʹ)–C(4ʹ)–H

θh1 [deg] e 107.9(8) 124.3(7) 126.4(8) 108.5(9) 107.0(7) 131.6(13) 116.9(10) 121.7(7) 122(6) 122(14)

N

N

O

N

Ti

N N

N N

N

878

Dihedral angles O=Ti–N(1)–C(1ʹ) Ti–N(1)–C(1ʹ)–N(2ʹ) Ti–N(1)–C(1ʹ)–C(2ʹ) N–C(2)…C(1ʹ)–C(2ʹ) Ti–N(1ʹ)…N–C(1ʹ) N(2ʹ)–C(1ʹ)…C(5ʹ)–N(1ʹ) C(3ʹ)–C(2ʹ)–C(2)–C(1ʹ) C(2)–C(3)…C(3ʹ)–C(4ʹ)

10 Molecules with Ten or More Carbon Atoms

τh1 [deg] e 80(3) 21(7) -166(4) -176(7) 157(3) 178.1 f 179.3 f -179.6 f

Reproduced with permission from the PCCP Owner Societies.

a Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Difference between parameters with equal superscripts were fixed at the value from the computation at the B3LYP level of theory (with cc-pVTZ basis set for the C, N, O and H atoms; (8s7p6d2f1g/6s5p3d2f1g) basis set and an ECP for the Ti valence and core shells, respectively). c Dependent parameter. d Height of the TiN4 square pyramid, where N are the central nitrogen atoms. e Parenthesized uncertainties in units of the last significant digit are 3σ values. f Adopted from computation as indicated above.

The combined GED/MS experiment was carried out at Teffusion cell = 764(10) K. No any ions corresponding to oligomeric species of the title molecule were detected by MS. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force field from B3LYP computation. Zakharov AV, Shlykov SA, Zhabanov YA, Girichev GV (2009) The structure of oxotitanium phthalocyanine: A gas-phase electron diffraction and computational study. Phys Chem Chem Phys 11 (18):3472-3477

10 Molecules with Ten or More Carbon Atoms

879

960 Oxo[29H,31H-phthalocyaninato-κN29,κN30,κN31,κN32]vanadium CAS RN: 13930-88-6 Vanadyl phthalocyanine MGD RN: 513209 C32H16N8OV GED combined with MS and augmented by C4v DFT computations

Distances V(1)=O(2) b V(1)–N(3) b N(3)–C(7) b N(16)–C(7) b C(7)–C(19) b C(19)–C(20) C(19)–C(21) b C(21)–C(23) C(23)–C(24) C(21)–H b C(23)–H N(3)...N(4) N(3)...N(5) N(3)...O(2) hd

rh1 [Å] a 1.584(11) 2.048(7) 1.378(9) 1.322(7) 1.457(7) 1.395(19) 1.394(4) 1.390(4) c 1.406(4) c 1.091(11) 1.091(11) 3.931(17) 2.780(12) 2.920(19) 0.576(14)

Bond angles N(3)–V(1)=O(2) b N(3)–V(1)–N(6) V(1)–N(3)–C(7) b N(3)–C(7)–N(16) C(7)–N(16)–C(14) C(7)–N(3)–C(8) N(3)–C(7)–C(19) C(7)–C(19)–C(20) C(20)–C(19)–C(21) C(19)–C(21)–C(23) C(21)–C(23)–C(24) N(16)–C(7)–C(19) C(7)–C(19)–C(21) b C(19)–C(21)–H b C(21)–C(23)–H

θh1 [deg] e

rg [Å] a 1.585(11) 2.049(7) 1.378(9) 1.326(7) 1.460(7) 1.399(19) 1.395(4) 1.391(4) 1.408(4) 1.096(11) 1.096(11) 3.917(17) 2.773(12) 2.924(19)

106.3(11) 85.5(6) 124.7(7) 127.6(7) 123.6(10) 108.7(7) 108.8(7) 106.8(6) 121.5(4) 117.1(7) 121.5(10) 123.3(9) 131.7(9) 125.1(41) 124.0(41) f

Dihedral angles N(6)–V(1)–N(3)–C(8) b C(8)–C(20)–C(19)–C(21) b C(20)–C(8)–C(7)–N(3) b C(24)–C(22)–C(21)–C(19) b

τh1 [deg] e

173.1(34) 179.4 g 177.3(51) 180.2(124)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Independent parameter.

880

10 Molecules with Ten or More Carbon Atoms

c

Difference to the C(19)–C(21) bond length was fixed at the value computed at the level of theory as indicated below. d Distance from the V(1) atom to the N(3)N(5)N(4)N(6) plane. e Parenthesized uncertainties in units of the last significant digit are 3σ values. f Difference to the C(19)–C(21)–H bond angle was fixed at the value from computation at the level of theory as indicataed below. g Fixed at the computed value. The GED experiment was carried out at Teffusion cell of 733(5) and 741(5) K at the short and long nozzle-to-plate distances, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra− rh1, were calculated using quadratic force constants from B3LYP/cc-pVTZ computation. Tverdova NV, Girichev GV, Krasnov AV, Pimenov OA, Koifman OI (2013) The molecular structure, bonding, and energetics of oxovanadium phthalocyanine: An experimental and computational study. Struct Chem 24 (3):883-890

961 [2,8,12,18-Tetraethyl-3,7,13,17-tetramethyl-21H,23H-porphinato-κN21,κN22,κN23,κN24]copper CAS RN: 14055-18-6 Copper(II) etioporphyrin II MGD RN: 447160 C32H36CuN4 GED combined with MS and augmented D2 by DFT computations H 3C

Bonds Cu–N N–C(1) C(1)–C(2) C(1)–C(3) C(2)–C(2ʹ) C(2)–C(6) C(2ʹ)–C(4) C(4)–C(5)

rh1 [Å] a,b 2.015(4) 1.374(4) 1.453(4) 1.391(3) 1.375(3) 1.498(4) 1.502(4) 1.542(4)

Bond angles Cu–N–C(1) C(1)–N–C(1ʹ) N–C(1)–C(2) C(1)–C(3)–C(1ʹʹ) C(1)–C(2)–C(2ʹ)

θh1 [deg] b,c

Dihedral angle C(1)–N…Nʹʹ–Cʹʹ)

τh1 [deg]

H 3C

CH3

N

N

CH3

N

CH3

Cu N

H 3C

H 3C

CH3

127.10(1) 105.8(2) 110.8(3) 125.45(4) 106.3(5)

0.4 d

Copyright 2015 with permission from Elsevier.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Average value is given for the chemically equivalent parameters; differences between these parameters were fixed at the values from computations with PBE functional as indicated below. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Fixed.

10 Molecules with Ten or More Carbon Atoms

881

Six conformers, characterized by different orientations of the ethyl groups relative to the porphyrin skeleton, were predicted by DFT computations using B3LYP and PBE functionals in conjunction with basis sets pVTZ (for H,C,N atoms) and cc-pVTZ (for Cu). Four of these conformers were predicted to be higher in energy by up to 0.3 kJ mol–1 in respect to the lowest energy conformer, whereas the relative energy of the sixth conformer was predicted to be very high. The most stable conformer with diagonally located ethyl groups on one side of the macroheterocycle and adjacent ethyl groups on the other side has D2 overall symmetry. In the GED analysis (Teffusion cell = 583(5) K), the molecules were assumed to exist as a single conformer with D2 point-group symmetry. It was shown that the GED intensities were not sensitive to conformational composition. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from DFT computations. Pogonin AE, Tverdova NV, Ischenko AA, Rumyantseva VD, Koifman OI, Giricheva NI, Girichev GV (2015) Conformation analysis of copper(II) etioporphyrin-II by combined gas electron diffraction/mass-spectrometry methods and DFT calculations. J Mol Struct 1085:276-285

962 [2,8,12,18-Tetraethyl-3,7,13,17-tetramethyl-21H,23H-porphinato-κN21,κN22,κN23,κN24]zinc CAS RN: 161043-86-3 Zinc(II) etioporphyrin II MGD RN: 412865 C32H36N4Zn GED combined with MS and augmented D2 by DFT computations

Distances Zn–N

rh1 [Å] a,b 2.042(5)

882

10 Molecules with Ten or More Carbon Atoms

N…N N–C(1) C(1)–C(2) C(1)–C(3) C(2)–C(2') C(2)–C(6) C(2')–C(4) C(4)–C(5)

2.889(7) 1.374(5) 1.453(4) 1.396(4) 1.376(4) 1.497(5) 1.501(5) 1.541(5)

Bond angles Zn–N–C(1) C(1')–N–C(1) N–C(1)–C(2) C(1)–C(3)–C(1'') C(1)–C(2)–C(2')

θh1 [deg] b,c

Dihedral angle C(1)–N…N''–C''

τh1 [deg]

126.8(2) 106.3(3) 110.4(5) 127.0(4) 106.5(7)

H3C

H 3C

CH3

N

CH3

N Zn

N

H 3C

H 3C

N

CH3

CH3

0.3 d

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Average values are given for the chemically equivalent parameters; differences between these parameters were fixed at the values from PBE computations (with cc-pVTZ basis set). c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Fixed. The occurrence of six conformers, characterized by different orientations of the ethyl groups relative to the porphyrin skeleton, was predicted by B3LYP and PBE computations (with cc-pVTZ basis set). Four of these

10 Molecules with Ten or More Carbon Atoms

883

conformers were predicted to be higher in energies by up to 0.3 kJ mol–1 only in comparison to the lowest energy conformer, whereas the relative energy of the sixth conformer was predicted to be very high. The lowest energy conformer, characterized by diagonally located ethyl groups on one side of the macroheterocycle and adjacent ethyl groups on the other side, has D2 point-group symmetry. The GED experiment was carried out at Teffusion cell of 557(5) and 570(5) K at the short and long camera distances, respectively. In the GED analysis, the molecule was assumed to exist as a single conformer with D2 overall symmetry. It was shown that the conformational composition could not be determined. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra – rh1, were calculated using quadratic force constants from PBE computation. Tverdova NV, Pogonin AE, Ischenko AA, Rumyantseva VD, Koifman OI, Giricheva NI, Girichev GV (2015) Combined gas-phase electron diffraction/mass spectrometry and DFT study of the molecular structure of zinc(II) etioporphyrin-II. Struct Chem 26 (5-6):1521-1530

963 CAS RN: 94928-86-6 MGD RN: 371880 GED combined with XRD and augmented by QC computations

Tris[2-(2-pyridinyl-κN)phenyl-κC]iridium C33H24IrN3 C3 N

a

Bonds Ir–C(8) Ir–N(2) N(2)–C(7) C(7)–C(6) C(6)–C(5) C(5)–C(4) C(4)–C(3) C(3)–N(2) C(9)–C(10) C(10)–C(11) C(11)–C(12) C(12)–C(13) C(13)–C(8) C(8)–C(9) C(3)–C(9) C–H

rh1 [Å] 2.033(6) 2.158(7) 1.357 b 1.388 b 1.396 b 1.392 b 1.404 b 1.374 b 1.412 b 1.392 b 1.399 b 1.397 b 1.415 b 1.429 b 1.458(9) 1.128(8) c

Bond angles N(2)–Ir–N(2') C(8)–Ir–C(8')

θh1 [deg] a

Dihedral angle C(8)–C(9)–C(3)–N(2)

τh1 [deg] a

Ir N

N

98(1) 93(1)

-5(3)

Copyright Wiley-VCH Verlag GmbH & Co. KGaA. Reproduced with permission.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. Assumed at the mean value of the XRD structure multiplied by the refined scaling factor fCC=1.0072(6). c Average value. b

884

10 Molecules with Ten or More Carbon Atoms

The GED experiment was carried out at the nozzle temperature of about 658 K. Overall C3 symmetry and planarity of the pyridylene and phenylene rings were assumed. The hydrogen atoms were placed exactly on the bisector of the corresponding C−C−C or C−C−N angle. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/TZVPP/ECP computation. Berger RJF, Stammler HG, Neumann B, Mitzel NW (2010) fac-Ir(ppy)3: Structures in the gas-phase and of a new solid modification. Eur J Inorg Chem (11):1613-1617

964 CAS RN: 14319-08-5 MGD RN: 150351 GED combined with MS and augmented by DFT computations

Distances Al–O C–O C–C(r) C–C(t) C(t)–C(methyl) C(methyl)–H O...O

rh1[Å] a 1.891(4) 1.270(3) 1.406(3) 1.535(3) 1.543(3) 1.095(3) 2.699(5) b

Bond angles O–Al–O Al–O–C O–C–C(t) C–C(t)–C(1) C–C(t)–C(1') C(t)–C(methyl)–H

θh1 [deg] c

Dihedral angles

τh1 [deg] c

d

ϕ γe

Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO3,κO5]aluminum Tris(dipivaloylmethanato)aluminum C33H57AlO6 D3 C) C (H3 3 (H3C)3C O O

O

C(CH3)3

Al O

O O

C(CH3)3

(H3C)3C (H3C)3C

91.0(7) 129.1(8) 114.6(10) 112.1(12) 107.1(11) 110.5(10)

32.8(14) 16.8(20)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Dependent parameter. c Parenthesized uncertainties in units of the last significant digit are 3σ values. d Angle of the ligand rotation around the Al…C(r) axis; ϕ = 0° for D3h overall symmetry.

10 Molecules with Ten or More Carbon Atoms

885

e

Torsional angle of the C(CH3) group; γ = 0° for the eclipsed position of this group with respect to the C–C(r) bond.

The GED experiment was carried out at Teffusion cell = 651(5) K. The methyl and tert-butyl groups were assumed to have local C3v and C2v symmetry, respectively. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP computation (with 6-311G*(Al) and D95*(C,O,F) basis sets). Belova NV, Dalhus B, Girichev GV, Giricheva NI, Haaland A, Kuzmima NP, Zhukova TA (2011) The molecular structure of tris-2,2,6,6-tetramethyl-heptane-3,5-dione aluminium: gas-phase electron diffraction, quantum chemical calculations and X-ray crystallography. Struct Chem 22 (2):393-399

Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO,κO’)cobalt 965 CAS RN: 1438428-34-2 Tris(dipivaloylmethanato)cobalt MGD RN: 515774 C33H57CoO6 GED combined with MS and augmented by D3 DFT computations

Bonds Co–O O–C C–C(r) C–C(t) C(t)–Cʹ C(t)–Cʹʹ C(t)–Cʹʹʹ C(methyl)–H

rh1 [Å] a 1.891(4) 1.269(3) 1.411(5) 1.546(3) 1.538(3)b 1.546(3) b 1.547(3) b 1.095(3) c

Bond angles O–Co–O C–C(r)–C Co–O–C O–C–C(t) C–C(t)–C(methyl) C(t)–C(methyl)–H

θh1 [deg] d

Dihedral angles

τh1 [deg] d

f

ϕ γg φh τ1 i

rg [Å] a 1.890(4) 1.270(3) 1.415(5) 1.549(3) 1.540(3) 1.549(3) 1.549(3) 1.100(3)

95.2(5) 122.5(9) e 125.2(6) 115.1(8) 112.2(8) c 107.5(9) c

36.4(14) 19.6(25) 33.0(7) e 172.1(55)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Differences between the C–C(t) and C(t)–C(methyl) bond lengths were assumed at the values from B3LYP/6311G* calculation. c Averaged. Differences between similar parameters were assumed at the values computed as above.

886

10 Molecules with Ten or More Carbon Atoms

d

Parenthesized uncertainties in units of the last significant digit are 3σ values. Dependent parameter. f Torsional angle of the ligand relative to its C2 axis from the D3h overall symmetry. g Torsional angle of the tert-butyl group, γ = 0° when the C(t)–C(methyl) bond is eclipsing the C–C(r) bond. h Torsional angle of the upper and lower O…O…O triangles relative to each other from the D3h overall symmetry. i Torsional angle of the methyl group. e

The GED experiment was carried out at Teffusion cell = 465 K. In the GED analysis, the title molecule was assumed to have D3 symmetry. Vibrational corrections to the experimental internuclear distances, Δrh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/6-311G* computation. Tverdova NV, Girichev GV, Samdal S (2013) The molecular structures of tris(dipivaloylmethanato)chromium and tris(dipivaloylmethanato)cobalt determined by gas electron diffraction and density functional theory calculations. Struct Chem 24 (3):891-900

Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO,κO’)chromium 966 CAS RN: 1438428-35-3 Tris(dipivaloylmethanato)chromium MGD RN: 515589 C33H57CrO6 GED combined with MS and augmented by D3 DFT computations

Bonds Cr–O O–C C–C(r) C–C(t) C(t)–Cʹ C(t)–Cʹʹ C(t)–Cʹʹʹ C(methyl)–H

rh1 [Å] a 1.976(5) 1.287(3) 1.392(6) 1.547(3) 1.542(3) b 1.550(3) b 1.550(3) b 1.105(3) c

Bond angles O–Cr–O C–C(r)–C Cr–O–C O–C–C(t) C–C(t)–C(methyl) C(t)–C(methyl)–H

θh1 [deg] d

Dihedral angles

τh1 [deg] d

ϕf γg φh τ1 i

rg [Å] a 1.959(5) 1.292(5) 1.418(6) 1.549(3) 1.543(3) 1.552(3) 1.551(3) 1.109(3)

90.1(9) 122.3(9) e 127.0(1) 114.7(9) 113.7(15) c 107.9(10) c

34.9(18) 26.5(43) 29.8(10) e 173.4(164)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Differences between the C–C(t) and C(t)–C(methyl) bond lengths were assumed at the values from B3LYP/6311G* calculation.

10 Molecules with Ten or More Carbon Atoms

887

c

Average value. Parenthesized uncertainties in units of the last significant digit are 3σ values. e Dependent parameter. f Torsional angle of the ligand relative to its C2 axis from the D3h overall symmetry. g Torsional angle of the tert-butyl group, γ = 0° when the C(t)–C(methyl) bond is eclipsing the C–C(r) bond. h Torsional angle of the upper and lower O…O…O triangles relative to each other from the D3h overall symmetry. i Torsional angle of the methyl group. d

The GED experiment was carried out at Teffusion cell = 453 K. In the GED analysis, the title molecule was assumed to have D3 symmetry. Vibrational corrections to experimental internuclear distances, Δrh1 = ra − rh1, were calculated using quadratic force constants from B3LYP/6-311G* computation. Tverdova NV, Girichev GV, Samdal S (2013) The molecular structures of tris(dipivaloylmethanato)chromium and tris(dipivaloylmethanato)cobalt determined by gas electron diffraction and density functional theory calculations. Struct Chem 24 (3):891-900

Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO,κO’)indium 967 CAS RN: 34269-03-9 Tris(dipivaloylmethanato)indium MGD RN: 147948 C33H57InO6 GED combined with MS and augmented by D3 DFT computations

Distances In–O O–C C–C(r) C–C(t) C(t)–C(1) C(t)–C(1′) b C(1)–H C(r)–H O...O

rh1 [Å] a 2.127(4) 1.268(3) 1.411(3) 1.543(3) 1.552(3) 1.539(3) 1.085(3) 1.066(3) c 2.884(6) c

Bond angles O–In–O In–O–C O–C–C(t) C–C(t)–C(1) C–C(t)–C(1′) b C(t)–C(1)–H

θh1 [deg] d

Dihedral angles

τh1 [deg] d

ϕe φf γg

85.4(5) 128.5(9) 113.7(19) 112.2(15) 107.3(17) 110.7(18)

30.2(15) 24.9(12) c 20.1(27)

Reproduced with permission of SNCSC.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r.

888

10 Molecules with Ten or More Carbon Atoms

b

C(1′) atom is located out-of-plane of the chelate ring. Dependent parameter. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e Torsional angle of the ligand relative to its C2 axis from the D3h total overall symmetry. f Twist angle of the upper and lower O…O…O triangles relative to each other from the D3h overall symmetry. g Torsional angle of the tert-butyl group around the C(t)–C(3) axis, γ = 0° when the C(t)–C(1) bond is eclipsing the C(3)–C(r) bond. c

The GED experiment was carried out at Teffusion cell = 387(9) K. It was assumed that the title molecule has a threefold symmetry axis, each of the dipivaloylmethanatoindium fragments has local C2 symmetry, each of the tert-butyl groups has local Cs symmetry, and each of the methyl groups has local C3v symmetry. Vibrational corrections to the experimental internuclear distances, Δrh1 = ra − rh1, were calculated with quadratic force constants computed at the B3LYP level of theory (in conjunction with double-ζ Dunning basis set as well as using effective core potential for In). Belova NV, Girichev GV, Haaland A, Zhukova TA, Kuzmima NP (2013) The molecular structure of tris2,2,6,6-tetramethyl-heptane-3,5-dione indium: Gas-phase electron diffraction and quantum chemical calculations. Struct Chem 24 (3):901-908

968 CAS RN: 15631-58-0 MGD RN: 413260 GED combined with MS and augmented by DFT computations

Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO3,κO5)thulium Tris(dipivaloylmethanato)thulium C33H57O6Tm H3C CH3 D3 H 3C

H 3C CH3

H3C

CH3

a,b

Distances Tm–O C–O C–C(r) C–C(t) C(t)–C' C(t)–C'' C(methyl)–H C(r)–H O...O

rh1 [Å] 2.214(5) c 1.278(4) c 1.404(3) 1,c 1.534(3) 1 1.527(3) 1 1.537(3) 1 1.092(3) 2,c 1.075(3) 2 2.750(11)

Bond angles O–Tm–O Tm–O–C O–C–C(r) C–C(r)–C O–C–C(t) C–C(t)–C' C–C(t)–C'' C(t)–C(methyl)–H

θh1 [deg] a

Dihedral angles φd γe ϕf

τh1 [deg] a

76.8(7) c 136.0(8) c 122.7(9) 125.8(23) 115.7(10) c 113.0(7) c 107.2(13) c 112.0(13) c

22.5(18) c 19.1(27) c 16.9(20)

Copyright 2016 with permission from Elsevier.

O O

O

Tm O

O

CH3 CH3 CH3

O

H 3C H 3C

CH3 CH3 CH3

H 3C

H 3C

CH3

10 Molecules with Ten or More Carbon Atoms

889

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r for the internuclear distances and 3σ values for the angles. b Parameters with equal superscript were refined in one group; differences between parameters in each group were fixed at the values from PBE0/cc-pVTZ(C,O,H),PP(Tm) computation. c Independent parameter. d Pitch angle of ligand rotation around the C2 axis from D3h total symmetry. e Torsional angle of the tert-butyl group around the C(t)–C axis, γ = 0° when the C(t)–C' bond is eclipsed with respect to the C–C(r) bond. f Twist angle of the upper and lower O…O…O triangles relative to each other from the D3h total symmetry. The GED experiment was carried out at Teffusion cell = 400(8) K. It was assumed that the molecule has a threefold symmetry axis, each of the ligands has local C2 symmetry, each of the tert-butyl groups has local Cs symmetry, and each of the methyl groups has local C3v symmetry. Vibrational corrections, ∆rh1 = ra − rh1, were calculated using quadratic force constants from DFT calculation at the level of theory as indicated above. Pimenov OA, Belova NV, Sliznev VV (2017) The molecular structure of tris(dipivaloylmethanato) thulium: Gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 1132:167-174

969 2,14,26-Tris(1,1-dimethylethyl)-7,10:19,22:31,34-triepithio-5,36:12,17:24,29CAS RN: 1058217-51-8 triimino[f,p,z][1,2,4,9,11,12,14,19,21,22,24,29]dodecaazacyclotricontine MGD RN: 364630 C42H39N15S3 GED combined with MS and augmented C3h by DFT computations

C(CH3)3

Distances N(p)–C(p1) N(p)–C(p1ʹ) C(p1)–N(m) C(p1ʹ)–N(mʹ) N(m)–C(t) N(mʹ)–C(tʹ) C(t)–N(t) C(tʹ)–N(tʹ) N(t)–N(tʹ) C(t)–S C(tʹ)–S C(p1)–C(p2) C(p1ʹ)–C(p2ʹ) C(p2)–C(p2ʹ) C(p2)–C(b1) C(p2ʹ)–C(b1ʹ) C(b1)–C(b2) C(b1ʹ)–C(b2ʹ) C(b2)–C(b2ʹ) C(b2ʹ)–C(bt) z.....N(t) d N(t)…N(tʹ) C(bt)–C(m) C(bt)–C(m')

rh1[Å] a,b,c 1.396(13) 1 1.395(13) 1 1.283(9) 2 1.283(9) 2 1.321(20) 3 1.321(20) 3 1.343(35) 4 1.343(35)4 1.311(31) 1.745(6) 5 1.745(6) 5 1.489(18) 6 1.491(18) 6 1.367(4) 1.398(13) 7 1.397(13) 7 1.400(13) 8 1.409(13) 8 1.418(50) 1.521(12) 2.749(20) 3.822(17) 1.529(12) 9 1.521(12) 9

Bond angles N(p)–C(p1)–N(m) N(p)–C(p1ʹ)–N(mʹ)

θh1 [deg] b,e

130.8(19) 10 130.9(19) 10

N S

HN N

N

N

N

(H3C)3C

N

NH

S

N

N

N

N

N HN

S

N

(H3C)3C

890

C(p1)–N(m)–C(t) C(p1ʹ)–N(mʹ)–C(tʹ) N(m)–C(t)–N(t) N(mʹ)–C(tʹ)–N(tʹ) N(m)–C(t)–S N(mʹ)–C(tʹ)–S N(t)–C(t)–S N(tʹ)–C(tʹ)–S N(p)–C(p1)–C(p2) N(p)–C(p1ʹ)–C(p2ʹ) C(p1)–C(p2)–C(p2ʹ) C(p1ʹ)–C(p2ʹ)–C(p2) C(p1)–C(p2)–C(b1) C(p1ʹ)–C(p2ʹ)–C(b1ʹ) C(p2)–C(b1)–C(b2) C(p2ʹ)–C(b1ʹ)–C(b2ʹ) C(b1)–C(b2)–C(b2ʹ) C(b1ʹ)–C(b2ʹ)–C(b2) C(b1ʹ)–C(b2ʹ)–C(bt)

10 Molecules with Ten or More Carbon Atoms

120.7(17) 11 120.7(17) 11 129.4(17) 12 129.4(17) 12 120.3(17) 120.6(32) 110.1(22) 110.2(15) 105.8(13) 13 105.8(13) 13 108.5(12) 14 108.3(12) 14 129.7(19) 15 128.5(19) 15 115.8(17) 16 117.0(17) 16 123.4(13) 118.8(12) 131.5(37)

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.001r.

10 Molecules with Ten or More Carbon Atoms

891

b

Parameters with equal superscript were refined in one group; difference between parameters in each group was assumed at the value from B3LYP computation. c Differences between some C–C, C–N and N–N bond lengths were assumed at the values from computation as indicated above. d z is the center of the macrocycle. e Parenthesized uncertainties in units of the last significant digit are 3σ values. The combined GED/MS experiment was carried out at Teffusion cell = 742(10) K. No any ions corresponding to oligomeric species of the title molecule were detected by MS. It was found that the molecule has planar skeleton, except for two out-of-plane carbon atoms in each tert-butyl group, and the thiadiazole rings oriented in such a way that the sulfur atoms point outwards from the inner cavity. The structural parameters are presented for a model of the single conformer characterized by the staggered conformation of each of the tert-butyl groups with respect to the C(b2ʹ)–C(b2) bond. Vibrational corrections to the experimental intenuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. The second conformer, characterized by eclipsed conformations of the tert-butyl groups with respect to the C(b2ʹ)–C(b2) bond, was indicated to be present in the vapor. According to B3LYP computations, this conformer is higher in energy than the most stable conformer by 1.4 kJ mol−1. Zakharov AV, Shlykov SA, Danilova EA, Krasnov AV, Islyaikin MK, Girichev GV (2009) Thiadiazolecontaining expanded heteroazaporphyrinoids: A gas-phase electron diffraction and computational structural study. Phys Chem Chem Phys 11 (38):8570-8579

970 1,3,5,7,9,11,13,15-Octaphenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane CAS RN: 5256-79-1 MGD RN: 371516 C48H40O12Si8 GED combined with MS and augmented D4 by DFT computations

Ddistances Si(1)…0c b O(9)…0c b O(13)–Si(1) Si(1)–C(1) C–C C–H C(2)–C(3) C(5)–C(4) C(6)–C(5) C(3)–C(4) C(1)–C(6) C(1)–C(2) Si(1)–O(9) Si(1)–O(14)

rh1 [Å] a 2.737(1) 2.695(20) 1.634(8) 1.859(1) 1.395(2) c 1.073(2) c 1.384(5) d 1.402(27) d 1.385(5) d 1.385(5) d 1.395(5) d 1.395(5) d 1.645(19) d 1.641(24) d

Angles Si(1)…0c…X b,e O(13)–Si(8)–O(12) C(1)–Si(1)–O(13) C(2)–C(1)–Si(1) C(6)–C(1)–Si(1) C(3)–C(2)–C(1) C(5)–C(6)–C(1) C(4)–C(3)–C(2)

θh1 [deg] a 124.8 f 108.3(2) 110.2(16) 119.8(8) 122.2(9) 121.9(12) 120.8(13) 119.7(14)

Si

O

O Si

O

O Si

O

Si

O O

Si O

Si O O Si

O Si

O

892

10 Molecules with Ten or More Carbon Atoms

Si(1)–O(13)–Si(8) O(13)–Si(1)–O(14) O(13)–Si(1)–O(9) O(14)–Si(1)–O(9) Si(1)–O(9)–Si(6) O(13)–Si(1)–C(1) C(6)–C(5)–C(4) C(3)–C(4)–C(5) C(2)–C(1)–C(6)

149.8(24) d 108.9(7) d 110.3(5) d 108.3(6) d 147.5(45) d 110.2(49) d 120.4(33) d 119.3(14) d 118.0(10) d

Dihedral angles Si(1)…0c…X…Z b,e,g O(13)–Si(8)–O(12)…0c b C(1)–Si(1)–O(13)…0c b C(2)–C(1)–Si(1)–O(9) C(6)–C(1)–Si(1)–O(9) C(3)–C(2)–C(1)–C(6) C(5)–C(6)–C(1)–C(2)

τh1 [deg] a

45.4 f -60.1 f -179.7 f 37.0(48) -145.5(31) -0.21 f 0.23 f

Reproduced with permission from The Royal Society of Chemistry.

a

Parenthesized uncertainties are the estimated standard deviations in units of the last significant digit. 0c is the centre of the coordinate system. c Average value. d Dependent parameter. e X is a dummy atom on the positive x axis. f Adopted from B3LYP/cc-pVTZ computation. g Z is a dummy atom on the positive z axis. b

10 Molecules with Ten or More Carbon Atoms

893

The GED experiment was carried out at Teffusion cell=615(10) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using harmonic force constants from B3LYP/cc-pVTZ computation. Zakharov AV, Masters SL, Wann DA, Shlykov SA, Girichev GV, Arrowsmith S, Cordes DB, Lickiss PD, White AJP (2010) The gas-phase structure of octaphenyloctasilsesquioxane Si8O12Ph8 and the crystal structures of Si8O12(p-tolyl)8 and Si8O12(p-ClCH2C6H4)8. Dalton Trans 39 (30):6960-6966

971 [2,9,16,23-Tetrakis(1,1-dimethylethyl)-29H,31H-phthalocyaninato-κN29,κN30,κN31,κN32]CAS RN: 39001-64-4 copper MGD RN: 414219 C48H48CuN8 GED combined with MS and augmented Cs (main conformer) by DFT computations H 3C

Bonds Cu–N(1) N(1)–C(1) C(1)–N(2) C(7)–C(8) C(2)–C(7) C(4)–C(10) C(3)–H

rh1 [Å] a 1.964(5) 1.378(3) 1.318(4) 1.448(5) 1.405(3) 1.542(4) 1.084(4)

Bond angles Cu–N(1)–C(1) N(1)–C(8)–C(7) C(2)–C(7)–C(6) C(2)–C(3)–H C(10)–C(12)–H C(12)–C(10)–C(4)

θh1 [deg] b

Dihedral angles C(12)–C(10)–C(4)–C(5) C(12)–C(10)–C(4')–C(5')

τh1 [deg]

125.6 c 109.9(5) 120.6(2) 122.9(60) 112.2(73) 112.0(13)

CH3

CH3

H3C H 3C H 3C

N

N

N Cu

N N

N N

N

CH3 CH3 CH3

H 3C H 3C

CH3

0.0 c,d 180.0 c,d

Reproduced with permission of SNCSC. a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parenthesized uncertainties in units of the last significant digit are 3σ values. c Fixed. d See comment below. The GED experiment was carried out at Teffusion cell = 709(8) K. Two conformers of the C4h point-group symmetry and three conformers with Cs symmetry, differing by combinations of the staggered and eclipsed conformations of the four tert-butyl groups with respect to the C(4)– C(5) bond, were predicted by UB3LYP computations (with cc-pVTZ and 6-31G* basis sets). According to free Gibbs energy calculations, amounts of two C4h conformers, I and II, characterized by all eclipsed and all staggered tert-butyl groups, respectively, are negligible small (1 and 2%, respectively), whereas three Cs conformers with one, two and three eclipsed tert-butyl groups occur at 709 K in amounts 67, 22 and 8 %, respectively. The best fit to the GED intensities was obtained for the model of a single conformer with one eclipsed tert-butyl group (torsional angle τ(C(12)–C(10)–C(4)–C(5))=0°)) and three other staggered ones (τ(C(12)–C(10)–C(4')– C(5'))=180°). The phthalocyanine moiety was found to be close to planar, i.e. with approximately D4h local symmetry.

894

10 Molecules with Ten or More Carbon Atoms

Vibrational corrections to the experimental bond lengths, ∆rh1 = ra − rh1, were calculated using quadratic force constants from computation at the level as indicated above.

Pimenov OA, Giricheva NI, Blomeyer S, Mayzlish VE, Mitzel NW, Girichev GV (2015) Gas-phase structure and conformations of copper(II) 2,9,16,23-tetra-tert-butyl phthalocyanine. Struct Chem 26 (5-6):1531-1541 972 [2,3,7,8,12,13,17,18-Octakis[3-(trifluoromethyl)phenyl]-21H,23HCAS RN: 475146-85-1 porphyrazinato-κN21,κN22,κN23,κN24]magnesium MGD RN: 422858 Magnesium octakis(3-trifluoromethylphenyl)porphyrazine GED combined with MS and augmented C72H32F24MgN8 by DFT computations D4

Bonds Mg(1)–N(2) N(2)–C(10) C(10)–C(18) N(6)–C(10) C(18)–C(24) C(18)–C(26) C(26)–C(34)

rh1 [Å] a,b 1.979(5) 1.363(3) 1 1.466(3) 2 1.334(4) 1 1.380(7) c 1.469(3) 2 1.400(3) 3

10 Molecules with Ten or More Carbon Atoms

C(26)–C(42) C(34)–C(50) C(42)–C(58) C(50)–C(66) C(58)–C(66) C(58)–C(98) C(98)–F(2) C(34)–H

895

1.400(5) 3 1.390(3) 3 1.389(3) 3 1.389(3) 3 1.394(3) 3 1.510(5) 2 1.349(3) 1.087(7)

F

F

F F

F

F

F

F

N

Bond angles Mg(1)–N(2)–C(10) C(10)–N(2)–C(16) C(10)–N(6)–C(15) C(10)–C(18)–C(24) C(10)–C(18)–C(26) C(18)–C(26)–C(42) C(42)–C(58)–C(66) C(42)–C(58)–C(98) C(58)–C(98)–F(2)

θh1 [deg]

F

N

N

125.7(3) 109.2(4) 124.2(6) 106.5(2) 123.9(8) 121(2) 121(1) 119(1) 112(11)

F

N

F

F

N

Mg

Copyright 2015 with permission from Elsevier.

τh1 [deg] d,f 132.6(9) 35.6 g

F

N

N

F

N

F

F

F

F F

F

Dihedral angles C(24)–C(18)–C(26)–C(34) C(66)–C(58)–C(98)–F(1)

F

d,e

F

F

F

896

10 Molecules with Ten or More Carbon Atoms

a

Parenthesized uncertainties in units of the last significant digit are estimated total errors including 2.5σ and a systematic error of 0.002r. b Parameters with equal superscripts were refined in one group; differences between parameters in each group were assumed at the values from B3LYP/cc-pVTZ computation. c Dependent parameter. d Parenthesized uncertainties in units of the last significant digit are 3σ values. e All C−C−H and F−C−F angles were fixed to the values from computation at the level of theory as indicated above. f All other dihedral angles, describing almost planar porphyrazine macrocycle and phenyl rings and being close to either 0 or 180°, were assumed at the values from computations as as indicated above. g Assumed at the value from computation as as indicated above. According to predictions of B3LYP/cc-pVTZ computations, the title molecule has the trifluoromethylphenyl groups in alternating orientation and D4 overall symmetry. In the GED analysis, the conformation of the molecule was assumed according to the DFT prediction. The GED experiment was carried out at Teffusion cell = 667(10) K. Vibrational corrections to the experimental internuclear distances, ∆rh1 = ra − rh1, were calculated using quadratic force constants from computation at the level of theory indicated above. Zhabanov YA, Zakharov AV, Giricheva NI, Shlykov SA, Koifman OI, Girichev GV (2015) To the limit of gasphase electron diffraction: Molecular structure of magnesium octa(m-trifluoromethylphenyl)porphyrazine. J Mol Struct 1092:104-112

10 References

897

References: 862

863 864 865

866

867 868

869

870 871 872 873 874 875 876 877 878

879 880

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898

10 Molecules with Ten or More Carbon Atoms

881 882 883

884 885

886 887 888 889 890 891

892 893 894 895

896 897 898

899 900

901

Neeman EM, Avilés-Moreno JR, Huet TR (2017) The quasi-unchanged gas-phase molecular structures of the atmospheric aerosol precursor β-pinene and its oxidation product nopinone. Phys Chem Chem Phys 19(4):13819-13827 Loru D, Bermúdez MA, Sanz ME (2016) Structure of fenchone by broadband rotational spectroscopy. J Chem Phys 145(7):074311/1-074311/8 Vishnevskiy YV, Abaev MA, Rykov AN, Gurskii ME, Belyakov PA, Erdyakov SY, Bubnov YN, Mitzel NW (2012) Structure and bonding nature of the strained Lewis acid 3-methyl-1boraadamantane: A case study employing a new data-analysis procedure in gas electron diffraction. Chem Eur J 18 (34):10585-10594 Wann DA, Turner AR, Goerlich JR, Kettle LJ, Schmutzler R, Rankin DWH (2011) Gas-phase structures of 1-adamantylphosphines, PHn(1-Ad)3-n (n = 1-3). Struct Chem 22 (2):263-267 Wann DA, Masters SL, Robertson HE, Green M, Kilby RJ, Russell CA, Jones C, Rankin DWH (2011) Multiple bonding versus cage formation in organophosphorus compounds: The gas-phase structures of tricyclo-P3(CBut)2Cl and P≡C-But determined by electron diffraction and computational methods. Dalton Trans 40 (20):5611-5616 Alikhanyan AS, Didenko KV, Girichev GV, Giricheva NI, Pimenov OA, Shlykov SA, Zhurko GA (2011) Gas-phase structure and conformational properties of copper (I) pivalate dimer (CuC5H9O2)2. Struct Chem 22 (2):401-409 Medcraft C, Schnell M (2016) A comparative study of two bicyclic ethers, eucalyptol and 1,4cineole, by broadband rotational spectroscopy. Z Phys Chem 230(1):1-14 Pérez C, Krin A, Steber AL, López JC, Kisiel Z, Schnell M (2016) Wetting camphor: multiisotopic substitution identifies the complementary roles of hydrogen bonding and dispersive forces. J Phys Chem Lett 7(1):154-160 See 888. See 888. Masters SL, Rankin DWH, Cordes DB, Bätz K, Lickiss PD, Boag NM, Redhouse AD, Whittaker SM (2010) The gas-phase structure and some reactions of the bulky primary silane (Me3Si)3CSiH3 and the solid-state structure of the bulky dialkyl disilane [(Me3Si)3CSiH2]2. Dalton Trans 39 (39):9353-9360 Khaikin LS, Tikhonov DS, Grikina OE, Rykov AN, Stepanov NF (2014) Quantum-chemical calculations and electron diffraction study of the equilibrium molecular structure of vitamin K3. Russ J Phys Chem A / Zh Fiz Khim 88 / 88 (5 / 5):886-889 / 895- 898 Écija P, Cocinero EJ, Lesarri A, Fernández JA, Caminati W, Castaño F (2013) Rotational spectroscopy of antipyretics: conformation, structure, and internal dynamics of phenazone. J Chem Phys 138(11):114304/1-114304/7 Lee I-R, Gahlmann A, Zewail AH (2012) Structural dynamics of free amino acids in diffraction. Angew Chem Int Ed/Angew Chem 51/124(1/1):99-102/103-106 Shainyan BA, Belyakov AV, Sigolaev YF, Khramov AN, Kleinpeter E (2017) Molecular structure and conformational analysis of 1-phenyl-1-X-1-silacyclohexanes (X = F, Cl) by electron diffraction, low-temperature NMR, and quantum chemical calculations. J Org Chem 82 (1):461-470 See 895. Shlykov SA, Phien TD, Gao Y, Weber PM (2017) Structure and conformational behavior of Nphenylpiperidine studied by gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 1132:3-10 Shainyan BA, Kirpichenko SV, Kleinpeter E, Shlykov SA, Osadchiy DY (2015) Molecular structure and conformational analysis of 3-methyl-3-phenyl-3-silatetrahydropyran. Gas-phase electron diffraction, low temperature NMR and quantum chemical calculations. Tetrahedron 71 (23):3810-3818 Shainyan BA, Kirpichenko SV, Osadchiy DY, Shlykov SA (2014) Molecular structure and conformations of 1-phenyl-1-silacyclohexane from gas-phase electron diffraction and quantum chemical calculations. Struct Chem 25 (6):1677-1685 (a) Belova NV, Trang NH, Oberhammer H, Girichev GV (2017) Tautomeric and conformational properties of dipivaloylmethane. J Mol Struct 1132:63-69 (b) Giricheva NI, Girichev GV, Lapshina SB, Kuzmina NP (2000) Molecular structure of dipivaloylmethane and the intramolecular hydrogen bond problem. J Struct Chem (Eng. Transl.)/Zh. Strukt Khim 41/41(1/1):48-54/58-66 Shlykov SA, Phien TD, Gao Y, Weber PM (2015) Molecular structure and conformational properties of N-cyclohexylpiperidine as studied by gas-phase electron diffraction, mass spectrometry, IR spectroscopy and quantum chemical calculations. Struct Chem 26 (5-6):15011512

10 References

902 903 904 905 906 907 908

909 910 911 912 913 914

915 916 917 918 919

920 921

922 923 924 925 926

899

Wann DA, Robinson MS, Bätz K, Masters SL, Avent AG, Lickiss PD (2015) Structures of tetrasilylmethane derivatives (XMe2Si)2C(SiMe3)2 (X = H, Cl, Br) in the gas phase, and their dynamic structures in solution. J Phys Chem A 119 (4):786-795 See 902. See 902. Steber AL, Pérez C, Temelso B, Shields GC, Rijs AM, Pate BH, Kisiel Z, Schnell M (2017) Capturing the elusive water trimer from the stepwise growth of water on the surface of the polycyclic aromatic hydrocarbon acenaphthene. J Phys Chem Lett 8(23):5744-5750 See 905. Seifert NA, Steber AL, Neill JL, Pérez C, Zaleski DP, Pate BH, Lesarri A (2013) The interplay of hydrogen bonding and dispersion in phenol dimer and trimer: structures from broadband rotational spectroscopy. Phys Chem Chem Phys 15(27):11468-11477 Daly AM, Lavin CM, Weidenschilling ES, Holden AM, Kukolich SG (2011) Microwave spectra, ab initio and DFT calculations and molecular structure for (η7-cycloheptatriene)Ti(η5cyclopentadienyl) and (η7-cycloheptatriene)Cr(η5-cyclopentadienyl). J Mol Spectrosc 267(12):172-177 Ksenafontov DN, Moiseeva NF, Rykov AN, Shishkov IF, Oberhammer H (2013) Molecular structure of carphedon as studied by gas electron diffraction and quantum chemical calculations. Struct Chem 24 (1):171-179 See 905. Shipman ST, Neill JL, Suenram RD, Muckle MT, Pate BH (2011) Structure determination of strawberry aldehyde by broadband microwave spectroscopy: Conformational stabilization by dispersive interactions. J Phys Chem Lett 2(5):443-448 See 911. See 905. Girichev GV, Giricheva NI, Pelevina ED, Tverdova NV, Kuz'mina NP, Kotova OV (2010) Structure of a zinc(II) N,N'-ethylene-bis(acetylacetoniminate) molecule, ZnO2N2C12H18, according to gas electron diffraction data and quantum chemical calculations. J Struct Chem (Engl Transl) / Zh Strukt Khim 51 / 51 (1 / 1):23-31 / 29-37 Lesarri A, Shipman ST, Neill JL, Brown GG, Suenram RD, Kang L, Caminati W, Pate BH (2010) Interplay of phenol and isopropyl isomerism in propofol from broadband chirped-pulse microwave spectroscopy. J Amer Chem Soc 132(38):13417-13424 Phien TD, Shlykov SA, Shainyan BA (2017) Molecular structure and conformational behavior of 1-methyl-1-phenylsilacyclohexane studied by gas electron diffraction, IR spectroscopy and quantum chemical calculations. Tetrahedron 73 (8):1127-1134 Weisheim E, Reuter CG, Heinrichs P, Vishnevskiy YV, Mix A, Neumann B, Stammler HG, Mitzel NW (2015) Tridentate Lewis acids based on 1,3,5-trisilacyclohexane backbones and an example of their host-guest chemistry. Chem Eur J 21 (35):12436-12448 Knapp CE, Wann DA, Bil A, Schirlin JT, Robertson HE, McMillan PF, Rankin DWH, Carmalt CJ (2012) Dimethylalkoxygallanes: Monomeric versus dimeric gas-phase structures. Inorg Chem 51 (5):3324-3331 Schwabedissen J, Lane PD, Masters SL, Hassler K, Wann DA (2014) Gas-phase structures of sterically crowded disilanes studied by electron diffraction and quantum chemical methods: 1,1,2,2-tetrakis(trimethylsilyl)disilane and 1,1,2,2-tetrakis(trimethylsilyl)dimethyldisilane. Dalton Trans 43 (26):10175-10182 See 919. Rybkin VV, Tverdova NV, Girichev GV, Shlykov SA, Kuzmina NP, Zaitseva IG (2011) Composition of overheated vapors and molecular structure of monomeric trishexafluoroacetylacetonates of lanthanum, neodymium and samarium. J Mol Struct 1006 (13):173-179 See 921. See 921. Blomeyer S, Linnemannstöns M, Nissen JH, Paulus J, Neumann B, Stammler HG, Mitzel NW (2017) Intramolecular π-π interactions in flexibly linked partially fluorinated bisarenes in the gas phase. Angew Chem Int Ed / Angew Chem 56/129 (43/43):13259-13263/13443-13447 Belova NV, Oberhammer H, Girichev GV (2011) Tautomeric and conformational properties of dibenzoylmethane, C6H5-C(O)-CH2-C(O)-C6H5: Gas-phase electron diffraction and quantum chemical study. Struct Chem 22 (2):269-277 Tverdova NV, Girichev GV, Shlykov SA, Kuz'mina NP, Petrova AA, Zaitseva IG (2013) A study of the structure and energy of β-diketonates. XVIII. Molecular structure of chromium

900

10 Molecules with Ten or More Carbon Atoms

927 928 929

930 931 932 933 934

935 936 937 938

939 940 941 942 943 944 945 946 947

948 949

and cobalt tris-acetylacetonates according to quantum chemical calculations and gas electron diffraction. J Struct Chem (Engl Transl)/Zh Strukt Khim 54/54 (5/5):863-875/825-837 See 926. Berger RJF, Girichev GV, Giricheva NI, Petrova AA, Tverdova NV (2017) The structure of Mn(acac)3 - experimental evidence of a static Jahn-Teller effect in the gas phase. Angew Chem Int Ed / Angew Chem 56 /129 (49 / 49):15751-15754 / 15958-15961 Giricheva NI, Girichev GV, Kuzmina NP, Medvedeva YS, Rogachev AY (2009) Structure of the Cu(salen) molecule CuO2N2C16H14 according to gas-phase electron diffraction data and quantum chemical calculations. J Struct Chem (Engl Transl) / Zh Strukt Khim 50/50(1/1):5259/58-65 Girichev GV, Giricheva NI, Tverdova NV, Simakov AO, Kuz'mina NP, Kotova OV (2010) Geometric and electronic structure of an N,N'-ethylene-bis(salicylaldiminato)zinc(II) molecule, ZnO2N2C16H14. J Struct Chem (Engl Transl)/Zh Strukt Khim 51/51(2/2):223-230/237-245 See 924. See 924. Wann DA, Dickson CN, Lickiss PD, Robertson HE, Rankin DWH (2011) The gas-phase equilibrium structures of Si8O12(OSiMe3)8 and Si8O12(CHCH2)8. Inorg Chem 50 (7):2988-2994 Choujaa H, Cosham SD, Johnson AL, Kafka GR, Mahon MF, Masters SL, Molloy KC, Rankin DWH, Robertson HE (2009) Structural tungsten-imido chemistry: The gas-phase structure of W(NBut)2(NHBut)2 and the solid-state structures of novel heterobimetallic W/N/M (M = Rh, Pd, Zn) species. Inorg Chem 48 (5):2289-2299 Tverdova NV, Giricheva NI, Savelyev DS, Mikhailov MS, Vogt N, Koifman OI, Stuzhin PA, Girichev GV (2017) Molecular structure of tetrakis(1,2,5-thiadiazolo)-porphyrazinatozinc(II) in gaseous phase. Macroheterocycles 10(1): 27-30 Körte LA, Schwabedissen J, Soffner M, Blomeyer S, Reuter CG, Vishnevskiy YV, Neumann B, Stammler HG, Mitzel NW (2017) Tris(perfluorotolyl)borane - a boron Lewis superacid. Angew Chem Int Ed / Angew Chem 56 /129 (29 /29):8578-8582 /8701-8705 Berger RJF, Rettenwander D, Spirk S, Wolf C, Patzschke M, Ertl M, Monkowius U, Mitzel NW (2012) Relativistic effects in triphenylbismuth and their influence on molecular structure and spectroscopic properties. Phys Chem Chem Phys 14 (44):15520-15524 (a) Campanelli AR, Domenicano A, Ramondo F, Hargittai I (2011) Molecular structure and conformation of triphenylsilane from gas-phase electron diffraction and theoretical calculations, and structural variations in H4-nSiPhn molecules (n = 1-4). Struct Chem 22 (2):361-369 (b) Rozsondai B, Hargittai I (1987) The molecular structure of triphenylsilane from gas-phase electron diffraction. J Organomet Chem 334:269-276 See 907. Wann DA, Reilly AM, Rataboul F, Lickiss PD, Rankin DWH (2009) The gas-phase structure of the hexasilsesquioxane Si6O9(OSiMe3)6. Z Naturforsch B 64(11-12):1269-1275 Gahlmann A, Lee I-R, Zewail AH (2010) Direct structural determination of conformations of photoswitchable molecules by laser desorption-electron diffraction. Angew Chem/Angew Chem Int Ed 122/49 (37/37):6674-6677/6524-6527 See 941.

Pérez C, Steber AL, Rijs AM, Temelso B, Shields GC, Lopez JC, Kisiel Z, Schnell M (2017) Corannulene and its complex with water: a tiny cup of water. Phys Chem Chem Phys 19(22):14214-14223

See 943. Tverdova NV, Pelevina ED, Giricheva NI, Girichev GV, Kuzmina NP, Kotova OV (2011) Molecular structure of N,N'-o-phenylene-bis(salicylideneaminato)copper(II) studied by gasphase electron diffraction and quantum-chemical calculations. Struct Chem 22 (2):441-448 Tverdova NV, Pelevina ED, Giricheva NI, Girichev GV, Kuzmina NP, Kotova OV (2012) Molecular structures of 3d metal complexes with various Schiff bases studied by gas-phase electron diffraction and quantum-chemical calculations. J Mol Struct 1012:151-161 Girichev GV, Giricheva NI, Tverdova NV, Pelevina ED, Kuzmima NP, Kotova OV (2010) Molecular structure of N,N'-o-phenylene-bis(salicylideneaminato)zinc(II), Zn(saloph), according to gas-phase electron diffraction and quantum-chemical calculations. J Mol Struct 978 (1-3):178-186 See 936. Otlyotov AA, Lamm JH, Blomeyer S, Mitzel NW, Rybkin VV, Zhabanov YA, Tverdova NV, Giricheva NI, Girichev GV (2017) Gas-phase structure of 1,8-bis[(trimethylsilyl)ethynyl]-

10 References

950 951

952 953 954 955 956 957

958

959 960 961

962 963 964

965 966 967 968

901

anthracene: cog-wheel-type vs. independent internal rotation and influence of dispersion interactions. Phys Chem Chem Phys 19 (20):13093-13100 See 933. Fokin AA, Zhuk TS, Blomeyer S, Perez C, Chernish LV, Pashenko AE, Antony J, Vishnevskiy YV, Berger RJF, Grimme S, Logemann C, Schnell M, Mitzel NW, Schreiner PR (2017) Intramolecular London dispersion interaction effects on gas-phase and solid-state structures of diamondoid dimers. J Am Chem Soc 139 (46):16696-16707 Girichev GV, Giricheva NI, Golubchikov OA, Mimenkov YV, Semeikin AS, Shlykov SA (2010) Octamethylporphyrin copper, C28H28N4Cu - A first experimental structure determination of porphyrins in gas phase. J Mol Struct 978 (1-3):163-169 Girichev GV, Giricheva NI, Koifman OI, Minenkov YV, Pogonin AE, Semeikin AS, Shlykov SA (2012) Molecular structure and bonding in octamethylporphyrin tin(II), SnN4C28H28. Dalton Trans 41 (25):7550-7558 See 951. Zhabanov YA, Zakharov AV, Shlykov SA, Trukhina ON, Danilova EA, Koifman OI, Islyaikin MK (2013) Molecular structure and tautomers of [30]trithia-2,3,5,10,12,13,15,20,22,23,25,30dodecaazahexaphyrin. J Porphyrins Phthalocyanines 17 (3):220-228 Lamm JH, Horstmann J, Stammler HG, Mitzel NW, Zhabanov YA, Tverdova NV, Otlyotov AA, Giricheva NI, Girichev GV (2015) 1,8-Bis(phenylethynyl)anthracene - gas and solid phase structures. Org Biomol Chem 13 (33):8893-8905 (a) Tverdova NV, Girichev GV, Giricheva NI, Pimenov OA (2011) Accurate molecular structure of copper phthalocyanine (CuN8C32H16) determined by gas-phase electron diffraction and quantum-chemical calculations. Struct Chem 22 (2):319-325 (b) Mastryukov V, Ruan C-Y, Fink M (2000) The molecular structure of copper- and nickelphthalocyanine as determined by gas-phase electron diffraction and ab initio/DFT computations. J Mol Struct 556:225-237 (a) Tverdova NV, Pimenov OA, Girichev GV, Shlykov SA, Giricheva NI, Mayzlish VE, Koifman OI (2012) Accurate molecular structure of nickel phthalocyanine (NiN8C32H16): Gasphase electron diffraction and quantum-chemical calculations. J Mol Struct 1023:227-233 (b) See 957(a). Zakharov AV, Shlykov SA, Zhabanov YA, Girichev GV (2009) The structure of oxotitanium phthalocyanine: A gas-phase electron diffraction and computational study. Phys Chem Chem Phys 11 (18):3472-3477 Tverdova NV, Girichev GV, Krasnov AV, Pimenov OA, Koifman OI (2013) The molecular structure, bonding, and energetics of oxovanadium phthalocyanine: An experimental and computational study. Struct Chem 24 (3):883-890 Pogonin AE, Tverdova NV, Ischenko AA, Rumyantseva VD, Koifman OI, Giricheva NI, Girichev GV (2015) Conformation analysis of copper(II) etioporphyrin-II by combined gas electron diffraction/mass-spectrometry methods and DFT calculations. J Mol Struct 1085:276285 Tverdova NV, Pogonin AE, Ischenko AA, Rumyantseva VD, Koifman OI, Giricheva NI, Girichev GV (2015) Combined gas-phase electron diffraction/mass spectrometry and DFT study of the molecular structure of zinc(II) etioporphyrin-II. Struct Chem 26 (5-6):1521-1530 Berger RJF, Stammler HG, Neumann B, Mitzel NW (2010) fac-Ir(ppy)3: Structures in the gasphase and of a new solid modification. Eur J Inorg Chem (11):1613-1617 Belova NV, Dalhus B, Girichev GV, Giricheva NI, Haaland A, Kuzmima NP, Zhukova TA (2011) The molecular structure of tris-2,2,6,6-tetramethyl-heptane-3,5-dione aluminium: gasphase electron diffraction, quantum chemical calculations and X-ray crystallography. Struct Chem 22 (2):393-399 Tverdova NV, Girichev GV, Samdal S (2013) The molecular structures of tris(dipivaloylmethanato)chromium and tris(dipivaloylmethanato)cobalt determined by gas electron diffraction and density functional theory calculations. Struct Chem 24 (3):891-900 See 965. Belova NV, Girichev GV, Haaland A, Zhukova TA, Kuzmima NP (2013) The molecular structure of tris-2,2,6,6-tetramethyl-heptane-3,5-dione indium: Gas-phase electron diffraction and quantum chemical calculations. Struct Chem 24 (3):901-908 Pimenov OA, Belova NV, Sliznev VV (2017) The molecular structure of tris(dipivaloylmethanato) thulium: Gas-phase electron diffraction and quantum chemical calculations. J Mol Struct 1132:167-174

902

10 Molecules with Ten or More Carbon Atoms

969 970

971 972

Zakharov AV, Shlykov SA, Danilova EA, Krasnov AV, Islyaikin MK, Girichev GV (2009) Thiadiazole-containing expanded heteroazaporphyrinoids: A gas-phase electron diffraction and computational structural study. Phys Chem Chem Phys 11 (38):8570-8579 Zakharov AV, Masters SL, Wann DA, Shlykov SA, Girichev GV, Arrowsmith S, Cordes DB, Lickiss PD, White AJP (2010) The gas-phase structure of octaphenyloctasilsesquioxane Si8O12Ph8 and the crystal structures of Si8O12(p-tolyl)8 and Si8O12(p-ClCH2C6H4)8. Dalton Trans 39 (30):6960-6966 Pimenov OA, Giricheva NI, Blomeyer S, Mayzlish VE, Mitzel NW, Girichev GV (2015) Gasphase structure and conformations of copper(II) 2,9,16,23-tetra-tert-butyl phthalocyanine. Struct Chem 26 (5-6):1531-1541 Zhabanov YA, Zakharov AV, Giricheva NI, Shlykov SA, Koifman OI, Girichev GV (2015) To the limit of gas-phase electron diffraction: Molecular structure of magnesium octa(mtrifluoromethylphenyl)porphyrazine. J Mol Struct 1092:104-112

Compound Index In this index the molecular structures are listed in alphabetical order of the sum formulae in Hill system. Therefore, the molecular structures of the inorganic molecules, which are presented in Chapter 2, are given in the beginning and in the end of the compound index. In between there is a block of 818 compounds containing one or more carbon atoms (Chapters 3 to 10). Entry No. 1

Molecular formula AgArI

MGD Chemical name RN 537270 Silver iodide – argon (1/1)

2

AgClH2

405223 Chloro(dihydrogen-H,H)silver

3

AgClH2O

215060 Silver chloride – water (1/1)

4

AgClH2S

212935 Silver chloride – hydrogen sulfide (1/1)

5

AgClH3N

214142 Silver chloride – ammonia (1/1)

6

AgFH2O

216055 Silver fluoride – water (1/1)

7

AgHS

349976 Silver hydrogen sulfide

8

AgH2

216264 Silver (1+)ion – dihydrogen (1/1)

9

AgH2IO

549396 Silver iodide – water (1/1)

10

AgH2IS

333978 Silver iodide – hydrogen sulfide (1/1)

11

AgH3IN

478020 Silver iodide – ammonia (1/1)

12

AgH3IP

342860 Silver iodide – phosphine (1/1)

13

AlBr3

387274 Aluminum(III) bromide

14

AlCl3

562634 Aluminum(III) chloride

15

AlF3

571004 Aluminum(III) fluoride

16

AlI3

598735 Aluminum(III) iodide

17

Al2Br6

336201 Di-µ-bromotetrabromodialuminum

18

Al2Cl6

229733 Di-µ-chlorotetrachlorodialuminum

19

Al2I6

603842 Di-µ-iodotetraiododialuminum

20

ArH2

170896 Dihydrogen – argon (1/1)

21

AsCl3

242165 Arsenous trichloride

22

AsHO

307008 Oxoarsine

23

AsH2

458081 Arsino

24

AsH2O

214351 Arsenooxy

25

AsH3

246569 Arsine

26

AsP3

349429 1,2,3-Triphospha-4-arsatricyclo[1.1.0.02,4]butane

27

As2B10H10

345338 1,2-closo-Diarsadodecaborane(10)

28

AuClH2

405051 Chloro(dihydrogen-H,H)gold

29

AuH2IS

500773 Gold(I) iodide – hydrogen sulfide (1/1)

30

BFH

214523 Fluoroborane(2)

31

BFH2O

948395 Fluorohydroxyborane

32

BF2

313328 Difluoroborane(2)

33

BF2HO

139475 Difluorohydroxyborane

34

BH2

138061 Borane(2)

35

BH3O2

496859 Boronic acid

© Springer Nature Switzerland AG 2019 N. Vogt and J. Vogt, Structure Data of Free Polyatomic Molecules, https://doi.org/10.1007/978-3-030-29430-4

903

904

Compound Index

36

BH6N

314779 Ammonia – borane (1/1)

37

B2H6

405850 Diborane(6)

38

B7H9S2

514661 6,8-Dithianonaborane(9)

39

B9H9S

146061 1-Thia-closo-decaborane(9)

40

B10H10P2

345500 1,2-closo-Diphosphadodecaborane(10)

41

BeI2

378308 Beryllium diiodide

42

Be2O

313709 Diberyllium oxide (1+)ion

43

BrGeH

137088 Bromogermylene

44

BrHO

623091 Hypobromous acid

45

Br2Fe

608794 Iron(II) bromide

46

Br2Na2

155125 Di-µ-bromodisodium

47

Br3Dy

156110 Dysprosium(III) bromide

48

Br3Lu

482007 Lutetium(III) bromide

49

Br4Fe2

326244 Di-µ-bromodibromodiiron

50

Br6Dy2

361720 Di-µ-bromotetrabromodidysprosium

155

CAgIO

333770 Silver iodide – carbon monoxide (1/1)

156

CAgN

531762 Silver(I) cyanide

157

CAlN

139310 Aluminum isocyanide

158

CArClF3

490996 Chlorotrifluoromethane – argon (1/1)

159

CArS2

103743 Carbon disulfide – argon (1/1)

160

CAuN

157388 Gold(I) cyanide

161

CBF3O

264760 Carbonyltrifluoroborane

162

CBrClO

133170 Carbon monoxide – bromine chloride (1/1)

163

CBrF2N

117483 N-Bromodifluoromethylenimine

164

CBrNO

113029 Bromine isocyanate

165

CBrN3O6

677622 Bromotrinitromethane

166

CClF2N

774041 N-Chlorodifluoromethylenimine

167

CClNO

803460 Chlorine isocyanate

168

CCl2F2

890168 Dichlorodifluoromethane

169

CCl2NOP

482150 Phosphorisocyanatidous dichloride

170

CCl2O

584337 Carbonic dichloride

171

CCl4

956069 Tetrachloromethane

172

CCl12Si4

361142 1,1ꞌ,1ꞌꞌ,1ꞌꞌꞌ-Methanetetrayltetrakis[1,1,1-trichlorosilane]

173

CFN3O6

518715 Fluorotrinitromethane

174

CFO2

146940 Fluorooxomethoxy

175

CF2O

862182 Carbonic difluoride

176

CF3IKr

309002 Trifluoroiodomethane – krypton (1/1)

177

CF3IN2

411611 Trifluoroiodomethane – dinitrogen (1/1)

178

CF3N

684361 Fluorocarbonimidic difluoride

179

CF8S

806669 Pentafluoro(trifluoromethyl)sulfur

180

CFeN

142246 Iron cyanide

181

CFeO

134603 Iron monocarbonyl

182

CHBr3

728903 Tribromomethane

Compound Index

905

183

CHClF2

583666 Chlorodifluoromethane

184

CHF2N

119704 Carbonimidic difluoride

185

CHN

806196 Hydrogen cyanide

186

CHNO

550070 Hydrogen isocyanate

187

CHNS

901163 Hydrogen isothiocyanate

188

CHNS

159394 Thiocyanic acid

189

CHNS

212310 Thiofulminic acid

190

CHNS

212112 Isothiofulminic acid

191

CHNZn

208497 (Cyano-C)hydrozinc

192

CHO2

965214 Hydroxyoxomethyl

193

CH2ArCl2

216018 Dichloromethane – argon (1/1)

194

CH2BrI

426440 Bromoiodomethane

195

CH2Br2

970760 Dibromomethane

196

CH2ClF

745463 Chlorofluoromethane

197

CH2ClF3O

213471 Chlorotrifluoromethane – water (1/1)

198

CH2ClI

736000 Chloroiodomethane

199

CH2Cl2

822290 Dichloromethane

200

CH2Cl2Ne

468904 Dichloromethane – neon (1/1)

201

CH2FI

175818 Fluoroiodomethane

202

CH2F2

558307 Difluoromethane

203

CH2F3IO

309192 Trifluoroiodomethane – water (1/1)

204

CH2F3IS

308644 Trifluoroiodomethane – hydrogen sulfide (1/1)

205

CH2N2

598409 Cyanamide

206

CH2O2

396420 Dioxymethyl

207

CH2O2

554714 Dihydroxymethylene

208

CH2O2

116505 Carbon monoxide – water (1/1)

209

CH2O3

982954 Carbonic acid

210

CH2O5S

456155 Formic acid anhydride with sulfuric acid

211

CH3Br2PS

956600 Phosphorodibromidothious acid methyl ester

212

CH3ClF2O

216786 Chlorodifluoromethane – water (1/1)

213

CH3ClF2Si

349245 Chlorodifluoromethylsilane

214

CH3ClF3N

333597 Chlorotrifluoromethane – ammonia (1/1)

215

CH3ClZn

444170 Chloromethylzinc

216

CH3Cl2PS

129181 Phosphorodichloridothious acid methyl ester

217

CH3F3IN

309407 Trifluoroiodomethane – ammonia (1/1)

218

CH3IZn

404865 Iodomethylzinc

219

CH3N

145550 Hydrogen cyanide – dihydrogen (1/1)

220

CH3NO

472260 Formamide

221

CH3NOS

115926 Carbonyl sulfide – ammonia (1/1)

222

CH3NO5

430730 Formic acid – nitric acid (1/1)

223

CH3O

109538 Methoxy

224

CH3O3

342453 Hydroxyoxomethyl – water (1/1)

225

CH4ClFSi

469279 (Chloromethyl)fluorosilane

906

Compound Index

226

CH4ClP

124578 (Chloromethyl)phosphine

227

CH4N2S

888960 Thiourea

228

CH4O3

416679 Dioxymethyl – water (1/1)

229

CH4Zn

157616 Hydromethylzinc

230

CH5BrSi

123000 (Bromomethyl)silane

231

CH5ClO

454186 Chloromethane – water (1/1)

232

CH5ClSi

616327 (Chloromethyl)silane

233

CH5FSi

213643 (Fluoromethyl)silane

234

CH5N

392340 Methanamine

235

CH8BN

112752 Trihydro(methanamine)boron

236

CH9NO4

525663 Formamide – water (1/3)

237

CHeS2

358696 Carbon disulfide – helium (1/1)

238

CKrO4S

410085 Carbon monoxide – sulfur trioxide – krypton (1/1/1)

239

CNP

210930 Cyanophosphinylidene

240

CNPt

209758 Cyano-κC-platinum

241

CN2O2

116136 Carbon dioxide – dinitrogen (1/1)

242

CN2O2

147358 Carbon monoxide – dinitrogen monoxide (1/1)

243

CN2O2S

145341 Carbonyl sulfide – dinitrogen monoxide (1/1)

244

CN2Si

408446 (Cyanoimino)silylene

245

CN4O8

121400 Tetranitromethane

246

CNeS2

130653 Carbon disulfide – neon (1/1)

247

CNiO

149980 Nickel monocarbonyl

248

COPd

145261 Palladium monocarbonyl

249

COPt

145992 Platinum monocarbonyl

250

CO3S

131361 Carbon monoxide – sulfur dioxide (1/1)

251

CS2

477869 Carbon disulfide

252

CSi2

134049 Methanetetraylbisilylene

253

C2AgCl

454543 (2-Chloroethynyl)silver

254

C2Al

215095 Aluminum acetylide

255

C2As

209525 Arsinidyneethenylidene

256

C2BrFN2

125723 (Z)-N-Bromocarbonocyanidimidic fluoride

257

C2BrF2N

214375 2-Bromo-2,2-difluoroacetonitrile

258

C2ClCu

454371 (2-Chloroethynyl)copper

259

C2ClFO2

387587 2-Chloro-2-oxo-acetyl fluoride

260

C2ClNOS

514083 Chloroisothiocyanatooxomethane

261

C2Cl2FNS

541116 Thiocyanic acid dichlorofluoromethyl ester

262

C2Cl2F2O

136817 Chlorodifluoroacetyl chloride

263

C2Cl2N2S

363854 3,4-Dichloro-1,2,5-thiadiazole

264

C2Cl3NS

536898 Thiocyanic acid trichloromethyl ester

265

C2F3IO

308828 Trifluoroiodomethane – carbon monoxide (1/1)

266

C2F4

359202 Tetrafluoroethene

267

C2Ge

545300 2,3-Didehydro-1H-germiren-1-ylidene

268

C2HAg

349614 Ethynylsilver

Compound Index

907

269

C2HAl

210689 Ethynylaluminum

270

C2HArClF2

210708 2-Chloro-1,1-difluoroethene – argon (1/1)

271

C2HAu

404484 Ethynylgold

272

C2HClF2

596324 2-Chloro-1,1-difluoroethene

273

C2HCr

409154 Ethynylchromium

274

C2HCu

213225 Ethynylcopper

275

C2HNO

113877 Carbon monoxide – hydrogen cyanide (1/1)

276

C2HNSi

408631 (Ethynylimino)silylene

277

C2HN2

837580 Cyanomethylidyneammonium

278

C2HO3

350348 Hydroxyoxomethyl – carbon monoxide (1/1)

279

C2HZn

340392 Ethynylzinc

280

C2H2

630082 Ethyne

281

C2H2AgCl

320368 Chloro(η2-ethyne)silver

282

C2H2ArClF

328956 (Z)-1-Chloro-2-fluoroethene – argon (1/1)

283

C2H2ArF2

322583 (Z)-1,2-Difluoroethene – argon (1/1)

284

C2H2AuI

438715 Iodo-(η2-ethyne)gold

285

C2H2ClCu

341898 Chloro(η2-ethyne)copper

286

C2H2ClF

297190 1-Chloro-1-fluoroethene

287

C2H2ClFO

386161 Fluoroacetyl chloride

288

C2H2ClF3

342190 1-Chloro-2,2,2-trifluoroethane

289

C2H2ClF3

453792 Difluoromethane – chlorofluoromethane (1/1)

290

C2H2ClF3

209630 1,1,2-Trifluoroethene – hydrogen chloride (1/1)

291

C2H2ClF3O

410269 Chlorotrifluoroethene – water (1/1)

292

C2H2ClNS

466610 Thiocyanic acid chloromethyl ester

293

C2H2CuF

456942 (η2-Ethyne)fluorocopper

294

C2H2F2

169180 1,1-Difluoroethene

295

C2H2F2OS

212394 Difluoromethane – carbonyl sulfide (1/1)

296

C2H2F2O2

342270 Difluoromethane – carbon dioxide (1/1)

297

C2H2F3NO

456327 2,2,2-Trifluoroacetonitrile – water (1/1)

298

C2H2N2O

477673 1,2,5-Oxadiazole

299

C2H2N2O

298345 1,3,4-Oxadiazole

300

C2H2O

244539 Ketene

301

C2H2O4

450384 Formic acid – carbon dioxide (1/1)

302

C2H3ArN

128504 Acetonitrile – argon (1/1)

303

C2H3As

133551 Ethylidynearsine

304

C2H3AsCl2

372076 Ethenylarsenous dichloride

305

C2H3ClF2

215857 1-Chloro-1-fluoroethene – hydrogen fluoride (1/1)

306

C2H3ClF2

216450 (E)-1-Chloro-2-fluoroethene – hydrogen fluoride (1/1)

307

C2H3ClF3N

451135 Chlorotrifluoroethene – ammonia (1/1)

308

C2H3ClF4

416471 Chlorotrifluoromethane – fluoromethane (1/1)

309

C2H3Cl2F

498054 (E)-1-Chloro-2-fluoroethene – hydrogen chloride (1/1)

310

C2H3Cl3Ge

368794 Trichloroethenylgermane

908

Compound Index

311

C2H3F2NOSi

350152 Difluoroisocyanatosilane

312

C2H3F3

211730 1,1-Difluoroethene – hydrogen fluoride (1/1)

313

C2H3F3

209457 (1E)-1,2-Difluoroethene – hydrogen fluoride (1/1)

314

C2H3F3O

648779 2,2,2-Trifluoroethanol

315

C2H3NO

380562 Isocyanatomethane

316

C2H3P

647039 Ethynylphosphine

317

C2H4AgCl

213286 Chloro(η2-ethene)silver

318

C2H4ClCu

324459 Chloro(η2-ethene)copper

319

C2H4ClF

354452 Chloroethene – hydrogen fluoride (1/1)

320

C2H4ClFO

390924 Chlorofluoromethane – formaldehyde (1/1)

321

C2H4Cl2F2

414778 Dichloromethane – difluoromethane (1/1)

322

C2H4FNOSi

408250 Fluoroisocyanatomethylsilane

323

C2H4F2O

931585 2,2-Difluoroethanol

324

C2H4F2O

378357 Difluoromethane – formaldehyde (1/1)

325

C2H4F3N

827733 2,2,2-Trifluoroethanamine

326

C2H4N2O

411790 Oxirane – dinitrogen (1/1)

327

C2H4O

103640 Ethenol

328

C2H4O

601340 Oxirane

329

C2H4O2

455773 Acetic acid

330

C2H4O2

692601 Formic acid methyl ester

331

C2H4O2

916188 2-Hydroxyacetaldehyde

332

C2H4O3

531135 1,2,4-Trioxolane

333

C2H4O3

427910 Formic acid – formaldehyde (1/1)

334

C2H4O4S2

517233 1,3-Dithietane 1,1,3,3-tetraoxide

335

C2H4O5S

546241 Acetic acid anhydride with sulfuric acid

336

C2H5As

137771 Ethenylarsine

337

C2H5FO

871615 2-Fluoroethanol

338

C2H5FO3

495802 2-Fluoroacetic acid – water (1/1)

339

C2H5F2N

771272 2,2-Difluoroethylamine

340

C2H5N

752731 (E)-Ethanimine

341

C2H5N

152577 (Z)-Ethanimine

342

C2H5N

153875 Aziridine

343

C2H5N

113700 Ethyne – ammonia (1/1)

344

C2H5NO

563471 N-Methylformamide

345

C2H5NO

125575 Acetonitrile – water (1/1)

346

C2H5NO2

855690 Nitroethane

347

C2H5NO2

346789 Aminoacetic acid

348

C2H5NO3

214873 Formic acid – formamide (1/1)

349

C2H5N3O2

521142 Urea – hydrogen isocyanate (1/1)

350

C2H5P

132806 Ethenylphosphine

351

C2H6ArO

148797 1,1'-Oxybismethane – argon (1/1)

352

C2H6ArS

211428 1,1'-Thiobismethane – argon (1/1)

Compound Index

909

353

C2H6Br4Si2

516513 1,1,1,2-Tetrabromo-2,2-dimethyldisilane

354

C2H6ClFO

214560 1-Chloro-1-fluoroethane – water (1/1)

355

C2H6FN

834380 2-Fluoroethanamine

356

C2H6N2O2

158115 Oxybismethane – dinitrogen monoxide (1/1)

357

C2H6O

492191 Ethanol

358

C2H6O

633846 1,1ꞌ -Oxybismethane

359

C2H6OS

693554 Sulfinylbis(methane)

360

C2H6O4S

993920 Sulfuric acid dimethyl ester

361

C2H6S

211219 1,1'-Thiobismethane

362

C2H7N

735236 Ethanamine

363

C2H7P

120580 Dimethylphosphine

364

C2H8N2

301077 1,2-Ethanediamine

365

C2H8N2O3

494553 Formamide – water (2/1)

366

C2H8P2

137132 1,2-Ethanediylbisphosphine

367

C2H9NO

349792 Ethanol – ammonia (1/1)

368

C2H10BN

363448 Trihydro(N-methylmethanamine)boron

369

C2H10B10I2

468154 9,12-Diiodo-1,2-dicarbadodecaborane(12)

370

C2H12B10

625729 1,2-Dicarba-closo-dodecaborane(12)

371

C2H12B10

266279 1,7-Dicarba-closo-dodecaborane(12)

372

C2H12B10S2

517417 9,12-Dimercapto-1,2-dicarbadodecaborane(12)

373

C2H13B7

514464 6,8-Dicarbanonaborane(13)

374

C2N2

950901 Ethanedinitrile

375

C2N2S

808269 Sulfur dicyanide

376

C2OS3

155254 Carbon disulfide – carbonyl sulfide (1/1)

377

C2O3

126105 Carbon dioxide – carbon monoxide (1/1)

378

C2O3S

118885 Carbon dioxide – carbonyl sulfide (1/1)

379

C2P

209039 Phosphinidyneethenylidene

380

C2S4

216079 Carbon disufide dimer

381

C2Sc

359400 [(1,2-η)-Ethyne-1,2-diyl]scandium

382

C2Y

151267 [(1,2- η)-Ethyne-1,2-diyl]yttrium

383

C3

328932 1,2-Propadiene-1,3-diylidene

384

C3AsF9

302615 Tris(trifluoromethyl)arsine

385

C3ClF2NO

365720 3-Chloro-3,3-difluoro-2-oxopropanenitrile

386

C3ClF2NOS

514279 2-Chloro-2,2-difluoroacetyl isothiocyanate

387

C3ClF2NO2

383644 2-Chloro-2,2-difluoroacetyl isocyanate

388

C3ClF5O

213410 2,2,3,3,3-Pentafluoropropanoyl chloride

389

C3Cl3N3

931131 2,4,6-Trichloro-1,3,5-triazine

390

C3F6O

536352 2,2,3,3,3-Pentafluoropropanoyl fluoride

391

C3F7I

211232 1,1,1,2,2,3,3-Heptafluoro-1-iodopropane

392

C3Ge2

503032 1,2-Propadiene-1,3-diylidenebisgermylene

393

C3HF3O2

439306 Trifluoroethene – carbon dioxide (1/1)

394

C3HF6N

428482 1,1,1,3,3,3-Hexafluoro-2-propanimine

910

Compound Index

395

C3H2

102408 2-Cyclopropen-1-ylidene

396

C3H2ArF4

543552 2,3,3,3-Tetrafluoro-1-propene – argon (1/1)

397

C3H2ClF5O

141631 2-Chloro-1-(difluoromethoxy)-1,1,2-trifluoroethane

398

C3H2ClF5O

143507 2-Chloro-2-(difluoromethoxy)-1,1,1-trifluoroethane

399

C3H2Cl4O2

536708 2,2,2-Trichloroethyl chloroformate

400

C3H2F2O2

439724 1,1-Difluoroethene – carbon dioxide (1/1)

401

C3H2F4

137457 2,3,3,3-Tetrafluoro-1-propene

402

C3H2F6O

151520 1,1,1,3,3,3-Hexafluoro-2-propanol

403

C3H3BrF2

215126 Ethyne – bromodifluoromethane (1/1)

404

C3H3ClF2

214326 Ethyne – chlorodifluoromethane (1/1)

405

C3H3ClO2

133065 Carbonochloridic acid ethenyl ester

406

C3H3FO2

430938 Fluoroethene – carbon dioxide (1/1)

407

C3H3F3O

833242 1,1,1-Trifluoro-2-propanone

408

C3H3F3O2

815501 2,2,2-Trifluoroacetic acid methyl ester

409

C3H3F3O2

214399 2,2,2-Trifluoroethanol 1-formate

410

C3H3N

711080 2-Propenenitrile

411

C3H3NO

297780 2-Oxopropanenitrile

412

C3H3NO2

781911 Acetyl isocyanate

413

C3H3NO3

510938 2-Propyn-1-ol nitrate

414

C3H4ArO

354279 2-Propyn-1-ol – argon (1/1)

415

C3H4ClF

214210 Ethyne – chlorofluoromethane (1/1)

416

C3H4ClF5O2

435412 2-Chloro-2-(difluoromethoxy)-1,1,1-trifluoroethane – water (1/1)

417

C3H4F3I

330442 Ethene – trifluoroiodomethane (1/1)

418

C3H4F4O

538020 Oxirane – tetrafluoromethane (1/1)

419

C3H4F6O2

442673 1,1,1,3,3,3-Hexafluoro-2-propanol – water (1/1)

420

C3H4N2

214897 (2E)-2-Iminopropanenitrile

421

C3H4N2

119199 (2Z)-2-Iminopropanenitrile

422

C3H4N2

961946 1H-Pyrazole

423

C3H4N2

786562 1H-Imidazole

424

C3H4O

188501 2-Propenal

425

C3H4OS

209250 Thiirane – carbon monoxide (1/1)

426

C3H4O2

643366 2-Propenoic acid

427

C3H4O2

333200 Oxirane – carbon monoxide (1/1)

428

C3H4O2S

213620 Thiirane – carbon dioxide (1/1)

429

C3H4O3

647513 Formic acetic anhydride

430

C3H4O3

213434 Oxirane – carbon dioxide (1/1)

431

C3H5ClF2

320737 Fluoroethene – chlorofluoromethane (1/1)

432

C3H5ClO

704677 Propanoyl chloride

433

C3H5ClO

364838 (2Z)-3-Chloro-2-propenol

434

C3H5ClO2

208670 2-Chloropropanoic acid

435

C3H5ClO2

112531 2-Chloroacetic acid methyl ester

436

C3H5FO4

414601 Fluoroaectic acid – formic acid (1/1)

437

C3H5F3

417258 Fluoroethene – difluoromethane (1/1)

Compound Index

911

438

C3H5F3O2

214025 1,1,1-Trifluoro-2-propanone – water (1/1)

439

C3H5NO

468732 2-Propenenitrile – water (1/1)

440

C3H5P

147280 2-Propynylphosphine

441

C3H5P

152866 1,2-Propadienylphosphine

442

C3H6

257399 1-Propene

443

C3H6AgCl

461780 Cyclopropane – silver chloride (1/1)

444

C3H6ClCu

461952 Cyclopropane – copper(I) chloride (1/1)

445

C3H6ClNO

519080 (2Z)-1-Chloro-2-propanone oxime

446

C3H6ClNO

147672 (2E)-1-Chloro-2-propanone oxime

447

C3H6Cl2

704966 2,2-Dichloropropane

448

C3H6F4Si2

378530 1,1,3,3-Tetrafluoro-1,3-disilacyclopentane

449

C3H6NP

153088 Dimethylphosphinous cyanide

450

C3H6N2

113109 3-Aminopropanenitrile

451

C3H6O

691259 Propanal

452

C3H6O

344631 2-Propen-1-ol

453

C3H6OS

210143 Thiobismethane – carbon monoxide (1/1)

454

C3H6O2

279828 Formic acid ethyl ester

455

C3H6O2

124935 Oxiranemethanol

456

C3H6O3

146571 Glyceraldehyde

457

C3H6O3

546068 Ethanol – carbon dioxide (1/1)

458

C3H6S

111640 2-Propene-1-thiol

459

C3H6S

600410 2-Methylthiirane

460

C3H7BrSi

374101 1-Bromosilacyclobutane

461

C3H7FSi

123594 (Fluorosilyl)cyclopropane

462

C3H7NO2

652720 2-Nitropropane

463

C3H7NO2

688857 L-Alanine

464

C3H7P

148380 2-Propenylphosphine

465

C3H8N4

316748 1-Azido-N,N-dimethylmethanamine

466

C3H8OS

442311 Formaldehyde – thiobis[methane] (1/1)

467

C3H8O2

442490 Formaldehyde – oxybis[methane] (1/1)

468

C3H8O3

489506 Oxybis[methane] – formic acid (1/1)

469

C3H8O3

159032 2-Oxiranemethanol – water (1/1)

470

C3H8Si

727390 Silacyclobutane

471

C3H9Br3Si2

515400 1,1,1-Tribromo-2,2,2-trimethyldisilane

472

C3H9Cl3Si2

515215 1,1,1-Trichloro-2,2,2-trimethyldisilane

473

C3H9F3Si2

515031 1,1,1-Trifluoro-2,2,2-trimethyldisilane

474

C3H9N

340379 2-Propanamine

475

C3H9NO2

209445 2-Oxiranemethanol – ammonia (1/1)

476

C3H10Ge

763456 Trimethylgermane

477

C3H10O2

533779 2-Propanol – water (1/1)

478

C3H10Si2

396050 1,3-Disilacylopentane

479

C3H12Si2

514869 1,1,1-Trimethyldisilane

912

Compound Index

480

C3N2O3

482345 Carbonic diisocyanate

481

C3O3

400805 Carbon monoxide trimer

482

C3O3S3

134584 Carbonyl sulfide trimer

483

C3O5

552769 Carbon dioxide – carbon monoxide (2/1)

484

C3O5S

140923 Carbon dioxide – carbonyl sulfide (2/1)

485

C3Pd

487330 1,2-Propadienylidenepalladium

486

C3Pt

487120 1,2-Propadienylideneplatinum

487

C3S6

216461 Carbon disulfide trimer

488

C4Br4S

383299 2,3,4,5-Tetrabromothiophene

489

C4Br4Se

383109 2,3,4,5-Tetrabromoselenophene

490

C4ClF10P

388166 P,P-Bis(1,1,2,2,2-pentafluoroethyl)phosphinous chloride

491

C4Cl2N4

360932 (2Z,3Z)-2,3-Bis(chloroimino)butanedinitrile

492

C4HF10OP

523227 P,P-Bis(1,1,2,2,2-pentafluoroethyl)phosphinous acid

493

C4HF10P

516144 Bis(1,1,2,2,2-pentafluoroethyl)phosphine

494

C4HNO

134086 2-Propynenitrile – carbon monoxide (1/1)

495

C4HNO2

136239 2-Propynenitrile – carbon dioxide (1/1)

496

C4H2ClNO2S

214511 2-Chloro-3-nitrothiophene

497

C4H2Cl2S

363633 2,5-Dichlorothiophene

498

C4H2F6

157481 3,3,3-Trifluoro-2-(trifluoromethyl)-1-propene

499

C4H2F6O2

356236 2,2,2-Trifluoroacetic acid 2,2,2-trifluoroethyl ester

500

C4H2O2S2

142086 Ethyne – carbonyl sulfide (1/2)

501

C4H2O3

679480 2,5-Furandione

502

C4H3Ag

411426 (η2-Ethyne)silver acetylide

503

C4H3FN2O2

328378 5-Fluoro-2,4(1H,3H)-pyrimidinedione

504

C4H3F5

428088 1,1,2,2,3-Pentafluorocyclobutane

505

C4H3F7O

143685 1,1,1,3,3,3-Hexafluoro-2-(fluoromethoxy)propane

506

C4H3NO2

665950 1H-Pyrrol-2,5-dione

507

C4H4ClF

210874 1-Chloro-1-fluoroethene – ethyne (1/1)

508

C4H4ClF

477821 (Z)-1-Chloro-2-fluoroethene – ethyne (1/1)

509

C4H4ClNO2

156195 1-Chloro-2,5-pyrrolidinedione

510

C4H4F2

215440 (1E,3E)-1,4-Difluoro-1,3-butadiene

511

C4H4F2

145562 (1E,3Z)-1,4-Difluoro-1,3-butadiene

512

C4H4F2

215648 (1Z,3Z)-1,4-Difluoro-1,3-butadiene

513

C4H4F8

549218 1,1,1,2-Tetrafluoroethane dimer

514

C4H4N2

874501 Butanedinitrile

515

C4H4N2

974051 Pyridazine

516

C4H4N2

941449 Pyrimidine

517

C4H4N2O2

245327 2,4(1H,3H)-Pyrimidinedione

518

C4H4N2O3

327450 2,4,6(1H,3H,5H)-Pyrimidinetrione

519

C4H4O

651888 Furan

520

C4H4O3

438186 Dihydro-2,5-furandione

521

C4H4O4

309770 (2E)-2-Butenedioic acid

Compound Index

913

522

C4H4O4

151095 2-Propynoic acid – formic acid (1/1)

523

C4H5Cl

391287 Chloroethene – ethyne (1/1)

524

C4H5Cl3O2

537084 Acetic acid 2,2,2-trichloroethyl ester

525

C4H5FO2

368444 (2Z)-3-Hydroxy-2-butenoyl fluoride

526

C4H5F3

474660 1,1-Difluoroethene – fluoroethene (1/1)

527

C4H5F3O

214559 1,1,1-Trifluoro-2-butanone

528

C4H5F3O

493901 (2,2,2-Trifluoroethoxy)ethene

529

C4H5F3OS

145410 Trifluoroethanethioic acid S-ethyl ester

530

C4H5F3O2

397114 2,2,2-Trifluoroacetic acid ethyl ester

531

C4H5N

359607 3-Isocyano-1-propene

532

C4H5N

415960 1H-Pyrrole

533

C4H5NO

111024 Isocyanatocyclopropane

534

C4H5NO2

154097 2,5-Pyrrolidinedione

535

C4H6

623459 Cyclobutene

536

C4H6BN

215636 1,2-Dihydro-1,2-azaborine

537

C4H6ClF3O

492873 1,1ꞌ-Oxybismethane – 1-chloro-1,2,2-trifluoroethene (1/1)

538

C4H6F2

402337 Propyne – difluoromethane (1/1)

539

C4H6F2O4

430545 Acetic acid – difluoroacetic acid (1/1)

540

C4H6N2O3

208565 2,4(1H,3H)-Pyrimidinedione – water (1/1)

541

C4H6O

709570 3-Buten-2-one

542

C4H6O2

208910 Acetic acid ethenyl ester

543

C4H6O2

644652 Cyclopropanecarboxylic acid

544

C4H6O3

379077 2-Oxopropanoic acid methyl ester

545

C4H6O3

462961 Acetic anhydride

546

C4H6O3

402130 2-Oxiranecarboxylic acid methyl ester

547

C4H6O3

213803 2-Methyloxirane – carbon dioxide (1/1)

548

C4H6O4

214688 Butanedioic acid

549

C4H6O4

376087 2-Propenoic acid – formic acid (1/1)

550

C4H7Br

185037 Bromocyclobutane

551

C4H7Cl

794875 Chlorocyclobutane

552

C4H7F

220112 Fluorocyclobutane

553

C4H7N

103282 2-Isocyanopropane

554

C4H7N

497045 2-Methylpropanenitrile

555

C4H7NO

113750 2-Isocyanatopropane

556

C4H7NO

542790 (E)-2-Methyl-2-propenal oxime

557

C4H7NOSi

469083 (Isocyanatosilyl)cyclopropane

558

C4H7NSi

426612 1-Cyclopropylsilanecarbonitrile

559

C4H8

329873 Ethene dimer

560

C4H8Cl2Si

189269 1,1-Dichloro-1-silacyclopentane

561

C4H8F4

545846 1,1-Difluoroethane dimer

562

C4H8KrO

332632 Tetrahydrofuran – krypton (1/1)

563

C4H8O

223396 Butanal

914

Compound Index

564

C4H8O

426243 Cyclobutanol

565

C4H8OS

460482 Oxirane – thiirane (1/1)

566

C4H8O2

482056 1,4-Dioxane

567

C4H8O3

212173 2,3-Butanedione – water (1/1)

568

C4H8O4

483839 2-Hydroxyacetaldehyde dimer

569

C4H9FSi

333026 1-Fluoro-1-silacyclopentane

570

C4H9F3IN

745893 N,N-Dimethylmethanamine – trifluoroiodomethane (1/1)

571

C4H9F3O3SSi

372814 1,1,1-Trifluoromethanesulfonic acid trimethylsilyl ester

572

C4H9I

495250 2-Iodobutane

573

C4H9N

295331 Aminocyclobutane

574

C4H9N

347290 Pyrrolidine

575

C4H9NOS

448106 Thionitrous acid S-(1,1-dimethylethyl) ester

576

C4H9NO2

286395 2-Methyl-2-nitropropane

577

C4H9NSeSi

518900 Isoselenocynatotrimethylsilane

578

C4H9OP

441744 1-(Dimethylphosphino)ethanone

579

C4H10Cl2Si

372992 Dichlorodiethylsilane

580

C4H10Ge

211115 Cyclopropylmethylgermane

581

C4H10Ge

737266 Cyclobutylgermane

582

C4H10O

917542 2-Butanol

583

C4H10O3

141723 1,4-Dioxane – water (1/1)

584

C4H10O4

320922 2-Hydroxypropanoic acid methyl ester – water (1/1)

585

C4H10Si

126930 Cyclopropylmethylsilane

586

C4H10Si

968277 Cyclobutylsilane

587

C4H10Si

647120 Silacyclopentane

588

C4H11NO

533940 4-Amino-1-butanol

589

C4H11NO2

479377 N,N-Dimethylmethanamine – formic acid (1/1)

590

C4H11NO3

335580 2-Hydroxypropanoic acid methyl ester – ammonia (1/1)

591

C4H11NO3Si

370403 1-(Trimethylsilyl)methanol 1-nitrate

592

C4H12OS

460304 1,1ꞌ-Oxybismethane – 1,1’-thiobismethane (1/1)

593

C4H12O2

215821 2-Methyl-2-propanol – water (1/1)

594

C4H12O2

148447 Ethanol dimer

595

C4H12O3Si

327253 1-(1,1-Dimethylethyl)silanetriol

596

C4H12Si2

317653 1,2-Disilacyclohexane

597

C4H12Si2

317481 1,3-Disilacyclohexane

598

C4H12Si2

317303 1,4-Disilacyclohexane

599

C4N4S

539655 1,2,5-Thiadiazole-3,4-dicarbonitrile

600

C4S8

400608 Carbon disulfide tetramer

601

C5F8

194648 Octafluorocyclopentene

602

C5F12

226454 Dodecafluoropentane

603

C5H2F5NO

488602 2,3,4,5,6-Pentafluoropyridine – water (1/1)

604

C5H2F6O2

515111 (3Z)-1,1,1,5,5,5-Hexafluoro-4-hydroxy-3-penten-2-one

605

C5H2F10

352864 1,1,1,2,2,3,4,5,5,5-Decafluoropentane

Compound Index

915

606

C5H3ArF2N

430350 2,3-Difluoropyridine – argon (1/1)

607

C5H3ArF2N

430164 2,4-Difluoropyridine – argon (1/1)

608

C5H3ArF2N

429990 2,5-Difluoropyridine – argon (1/1)

609

C5H3ArF2N

429811 2,6-Difluoropyridine – argon (1/1)

610

C5H3ArF2N

429626 3,5-Difluoropyridine – argon (1/1)

611

C5H3F2N

329688 2,3-Difluoropyridine

612

C5H3F2N

329500 2,4-Difluoropyridine

613

C5H3F2N

330085 2,5-Difluoropyridine

614

C5H3F2N

577950 2,6-Difluoropyridine

615

C5H3F2N

352526 3,5-Difluoropyridine

616

C5H3F5O

372248 1,3,3,4,4-Pentafluoro-2-methoxycyclobutene

617

C5H4ArF

392259 2-Fluoropyridine – argon (1/1)

618

C5H4ArF

392051 3-Fluoropyridine – argon (1/1)

619

C5H4ClNO

532285 5-Chloro-2(1H)-pyridinone

620

C5H4ClNO

533036 5-Chloro-2-pyridinol

621

C5H4ClNO

533210 6-Chloro-2-pyridinol

622

C5H4FN

606499 2-Fluoropyridine

623

C5H4FN

240370 3-Fluoropyridine

624

C5H4O

375804 2,4-Cyclopentadien-1-one

625

C5H4OS

145328 Ethyne – carbonyl sulfide (2/1)

626

C5H5ArNNe

212984 Pyridine – argon – neon (1/1/1)

627

C5H5ArTl

211490 (η5-2,4-Cyclopentadien-1-yl)thallium – argon (1/1)

628

C5H5F3O4

259553 2-Propenoic acid – 2,2,2-trifluoroacetic acid (1/1)

629

C5H5N

183542 Pyridine

630

C5H5NNe2

212382 Pyridine – neon (1/2)

631

C5H5NOS

333419 1-Hydroxy-2(1H)-pyridinethione

632

C5H5NO4

487525 1H-Pyrrole-2,5-dione – formic acid (1/1)

633

C5H5N3O

539839 Pyrazinamide

634

C5H5N5

871302 9H-Purin-6-amine

635

C5H5N5O

209304 2-Amino-1,7-dihydro-6H-purin-6-one

636

C5H6

843315 Tricyclo[1.1.1.01,3]pentane

637

C5H6FNO

531381 2-Fluoropyridine – water (1/1)

638

C5H6FNO

493071 3-Fluoropyridine – water (1/1)

639

C5H6N2O2

413075 1-Methyl-2,4(1H,3H)-pyrimidinedione

640

C5H6N2O2

127415 5-Methyl-2,4-(1H,3H)-pyrimidinedione

641

C5H7ClO

944490 Cyclobutanecarbonyl chloride

642

C5H7N

344409 Cyanocyclobutane

643

C5H7NO

378726 Isocyanotocyclobutane

644

C5H8

183068 1,4-Pentadiene

645

C5H8

382254 Spiropentane

646

C5H8

504907 Bicyclo[1.1.1]pentane

647

C5H8ArO

158489 6-Oxabicyclo[3.1.0]hexane – argon (1/1)

916

Compound Index

648

C5H8N2

534125 Pyridine – ammonia (1/1)

649

C5H8N2O3

208750 5-Methyl-2,4(1H,3H)-pyrimidinedione – water (1/1)

650

C5H8O2

518531 2,4-Pentanedione

651

C5H8O2

369569 (3Z)-4-Hydroxy-3-penten-2-one

652

C5H8O3

533571 Cyclobutanone – formic acid (1/1)

653

C5H8O4

461417 Cyclopropanecarboxylic acid – formic acid (1/1)

654

C5H9F

212960 Fluorocyclopentane

655

C5H9F3O2Si

375165 2,2,2-Trifluoroacetic acid trimethylsilyl ester

656

C5H9NO

144750 2-Piperidinone

657

C5H9NO2

148042 Proline

658

C5H9NO3S

156785 2,2-Dimethylpropanenitrile – sulfur trioxide (1/1)

659

C5H9N3

130641 Histamine: 4-(2-Aminoethyl)imidazole

660

C5H9N3

552014 Histamine: 5-(2-Aminoethyl)imidazole

661

C5H9P

954389 2,2-Dimethylpropylidynephosphine

662

C5H10F2

216215 3,3-Difluoropentane

663

C5H10N2O

305851 2-(Dimethylamino)-2-methoxyacetonitrile

664

C5H10O

470555 Tetrahydro-2-methylfuran

665

C5H10O2

210259 5-Methyl-1,3-dioxane

666

C5H10O4

394148 2-Deoxy-ß-D-erythro-pentopyranose

667

C5H10O5

393766 α-D-Xylopyranose

668

C5H11BrSi

328563 1-Bromosilacyclohexane

669

C5H11ClSi

327996 1-Chlorosilacyclohexane

670

C5H11ISi

328182 1-Iodo-1-silacyclohexane

671

C5H11N

415529 Cyclopentanamine

672

C5H11N

404607 Piperidine

673

C5H11NO3

370593 2,2-Dimethyl-1-propanol 1-nitrate

674

C5H12F2O

543195 2-Methyl-2-propanol – difluoromethane (1/1)

675

C5H12N4O2

386068 N,N,N’,N’-Tetramethyl-N’-nitroguanidine

676

C5H12OSi

467970 3-Methyl-1-oxa-3-silacyclohexane

677

C5H12O2

545674 2-Propanone – ethanol (1/1)

678

C5H12SSi

467803 3-Methyl-1-thia-3-silacyclohexane

679

C5H13GaO2

382008 Dimethyl[2-(methoxy-κO)ethanolato-κO]gallium

680

C5H14O2

213679 2-Propanol – oxybismethane (1/1)

681

C5H14Si2

211281 1-Silylsilacyclohexane

682

C5H15NSi

516330 1,3-Dimethyl-1-aza-3-silacyclohexane

683

C6F6

428574 Hexafluorobenzene

684

C6F15P

370962 Tris(1,1,2,2,2-pentafluoroethyl)phosphine

685

C6HF5

781505 Pentafluorobenzene

686

C6H2N2

132289 2-Propynenitrile dimer

687

C6H3F2NO2

409916 2,6-Difluoropyridine – carbon dioxide (1/1)

688

C6H3F2NO2

495064 3,5-Difluoropyridine – carbon dioxide (1/1)

689

C6H3N3O6

363878 1,3,5-Trinitrobenzene

Compound Index

917

690

C6H3N3O9S

384192 2,4,6-Trinitrobenzenesulfonic acid

691

C6H4BrF

268537 1-Bromo-4-fluorobenzene

692

C6H4ClF

589658 1-Chloro-4-fluorobenzene

693

C6H4ClNO4S

387760 2-Nitrobenzenesulfonyl chloride

694

C6H4ClNO4S

152332 4-Nitrobenzenesulfonyl chloride

695

C6H4FNO4S

213065 2-Nitrobenzenesulfonyl fluoride

696

C6H4F2

957078 1,2-Difluorobenzene

697

C6H4F2

387089 1,3-Difluorobenzene

698

C6H4F2

600458 1,4-Difluorobenzene

699

C6H4F2O

148331 2,4-Difluorophenol

700

C6H5

149376 Phenyl

701

C6H5F

628720 Fluorobenzene

702

C6H5FO

898640 2-Fluorophenol

703

C6H5FO

335241 3-Fluorophenol

704

C6H5FS

541687 2-Fluorobenzenethiol

705

C6H5F4N

208608 Pyridine – tetrafluoromethane (1/1)

706

C6H5I

949411 Iodobenzene

707

C6H5INe

216657 Iodobenzene – neon (1/1)

708

C6H5NO2

390162 Nitrobenzene

709

C6H5NO2

427737 2-Pyridinecarboxylic acid

710

C6H5NO2

211569 Pyridine – carbon dioxide (1/1)

711

C6H5NO5S

213606 2-Nitrobenzenesulfonic acid

712

C6H5NO5S

344380 3-Nitrobenzenesulfonic acid

713

C6H6

595991 Benzene

714

C6H6

693879 Tris(methylene)cyclopropane

715

C6H6

117655 Ethyne trimer

716

C6H6F2O

147322 1,4-Difluorobenzene – water (1/1)

717

C6H6F3N

211244 Pyridine – trifluoromethane (1/1)

718

C6H6F4O2

368087 3,3,4,4-Tetrafluoro-1,2-dimethoxycyclobutene

719

C6H6He

144657 Benzene – helium (1/1)

720

C6H6He2

144450 Benzene – helium (1/2)

721

C6H6N2O4S

213796 2-Nitrobenzenesulfonamide

722

C6H6Ne

129170 Benzene – neon (1/1)

723

C6H6O3S

384014 Benzenesulfonic acid

724

C6H6O4

465164 3,4-Dimethoxy-3-cyclobutene-1,2-dione

725

C6H7FO

148435 Fluorobenzene – water (1/1)

726

C6H7F2N

215243 1,4-Difluorobenzene – ammonia (1/1)

727

C6H7F2N

418789 Pyridine – difluoromethane (1/1)

728

C6H7NO2

492690 Pyridine – formic acid (1/1)

729

C6H7P

329511 Phenylphosphine

730

C6H8

673555 (3E)-1,3,5-Hexatriene

731

C6H8

412503 Benzene – dihydrogen (1/1)

918

Compound Index

732

C6H8FN

418600 Pyridine – fluoromethane (1/1)

733

C6H8N2O2

419725 1,5-Dimethyl-2,4(1H,3H)-pyrimidinedione

734

C6H8N4

489727 1H-Imidazole dimer

735

C6H8O2

375160 2-Hydroxy-2-cyclohexen-1-one

736

C6H8O2

387956 1,3-Cyclohexanedione

737

C6H8O2

125434 1,4-Cyclohexanedione

738

C6H9N

182490 Cyclopentanecarbonitrile

739

C6H9N

409340 Isocyanocyclopentane

740

C6H9N

211430 Pyridine – methane (1/1)

741

C6H10

418220 Benzene – dihydrogen (1/2)

742

C6H10ArO

354102 7-Oxabicyclo[4.1.0]heptane – argon (1/1)

743

C6H10N2

540771 1-Piperidinecarbonitrile

744

C6H10N2O2

214154 2-Oxo-1-pyrrolidineacetamide

745

C6H10O2

383816 (3Z)-4-Hydroxy-3-methyl-3-penten-2-one

746

C6H10O2

796703 2-Oxepanone

747

C6H10O3

544733 Tetrahydro-4-hydroxy-4-methyl-2H-pyran-2-one

748

C6H11Br

992310 Bromocyclohexane

749

C6H11Cl

894493 Chlorocyclohexane

750

C6H11F

128701 Fluorocyclohexane

751

C6H11NO

213840 1-Methyl-4-piperidinone

752

C6H11NSSi

362894 2-(Trimethylsilyl)thiazole

753

C6H11NSi

505640 Silacylohexane-1-carbonitrile

754

C6H12

821476 Cyclohexane

755

C6H12

358868 Ethene trimer

756

C6H12F6Si2

317118 1,1,2,2-Tetramethyl-1,2-bis(trifluoromethyl)disilane

757

C6H12N2

468547 3,3-Dimethyl-1,5-diazabicyclo[3.1.0]hexane

758

C6H12N2

468351 6,6-Dimethyl-1,5-diazabicyclo[3.1.0]hexane

759

C6H12N4

300996 1,3,5,7-Tetraazatricyclo[3.3.1.13,7]decane

760

C6H12O

440298 Hexanal

761

C6H12O2

414035 Cyclobutanone – ethanol (1/1)

762

C6H12O6

389833 ß-D-Fructopyranose

763

C6H13FSi

372598 1-Fluoro-1-methylsilacyclohexane

764

C6H14Ge

216610 Cyclohexylgermane

765

C6H14Si

128067 Cyclohexylsilane

766

C6H16GaNO

208528 [2-(Dimethylamino)ethanolato-N,O]dimethylgallium

767

C6H16O2

308460 2-Methyl-2-propanol – 1,1'-oxybismethane (1/1)

768

C7F5N

145120 2,3,4,5,6-Pentafluorobenzonitrile

769

C7F14

374451 1,1,2,2,3,3,4,4,5,5,6-Undecafluoro-6-(trifluoromethyl)cyclohexane

770

C7H3F2N

132070 2,3-Difluorobenzonitrile

771

C7H3F2N

462310 2,4-Difluorobenzonitrile

772

C7H4BrClO

517050 2-Bromobenzoyl chloride

773

C7H4ClFO

516691 2-Fluorobenzoyl chloride

Compound Index

919

774

C7H4Cl2O

516875 2-Chlorobenzoyl chloride

775

C7H4FN

368628 2-Fluorobenzonitrile

776

C7H4FN

116124 3-Fluorobenzonitrile

777

C7H5F3

383969 (Trifluoromethyl)benzene

778

C7H5F3O

147506 (Trifluoromethoxy)benzene

779

C7H5N

597150 Cyanobenzene

780

C7H6F2

462715 1,3-Difluoro-2-methylbenzene

781

C7H6F2

462520 1,3-Difluoro-5-methylbenzene

782

C7H6F2

543005 1,4-Difluoro-2-methylbenzene

783

C7H6HeOS

213981 Benzene – carbonyl sulfide – helium (1/1/1)

784

C7H6NeOS

214166 Benzene – carbonyl sulfide – neon (1/1/1)

785

C7H6OS

135925 Benzene – carbonyl sulfide (1/1)

786

C7H6O2

341468 2-Hydroxybenzaldehyde

787

C7H6O3

210200 2-Hydroxybenzoic acid

788

C7H7F3

155647 Benzene – trifluoromethane (1/1)

789

C7H7F3O2

417640 (Trifluoromethoxy)benzene – water (1/1)

790

C7H7N

443227 Pyridine – ethyne (1/1)

791

C7H7NO

145248 N-Phenylformamide

792

C7H7NO

142603 (E)-Benzaldehyde oxime

793

C7H7NO

144006 Benzamide

794

C7H7NO2

513559 2-Hydroxybenzamide

795

C7H7NO3

548338 1-Methoxy-4-nitrobenzene

796

C7H7NO3S

457127 1-(Methylsulfinyl)-4-nitrobenzene

797

C7H7NO5S

415148 2-Nitrobenzenesulfonic acid methyl ester

798

C7H7NO5S

344563 4-Nitrobenzenesulfonic acid methyl ester

799

C7H8FN

375331 2-Fluorobenzenemethanamine

800

C7H8O2

211686 2-Methoxyphenol

801

C7H8O3

417455 Benzoic acid – water (1/1)

802

C7H8O3S

344169 4-Methylbenzenesulfonic acid

803

C7H9P

361928 (Phenylmethyl)phosphine

804

C7H10

117380 Ethynylcyclopentane

805

C7H10F3NO

540390 2,2,2-Trifluoro-1-(1-piperidinyl)ethanone

806

C7H10O

890586 3-Oxatricyclo[3.2.1.02,4]octane

807

C7H10O2

152006 Methoxybenzene – water (1/1)

808

C7H10O4

429430 2-Hydroxy-2-cyclohexen-1-one – formic acid (1/1)

809

C7H11N

856716 Cyclohexanecarbonitrile

810

C7H11NO

585703 Isocyanatocyclohexane

811

C7H11NO

209341 Methoxybenzene – ammonia (1/1)

812

C7H13F3Si

372421 1-Methyl-1-(trifluoromethyl)silacyclohexane

813

C7H17NSi

382881 1,3,3-Trimethyl-1-aza-3-silacyclohexane

814

C8F15N

216971 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Pentadecafluorooctanenitrile

815

C8H4N2

478528 1,4-Diisocyanobenzene

920

Compound Index

816

C8H4O3

413665 1,3-Isobenzofurandione

817

C8H4O8

503580 Ethyne – carbon dioxide (2/4)

818

C8H5F

498447 1-Ethynyl-3-fluorobenzene

819

C8H5F

508840 1-Ethynyl-4-fluorobenzene

820

C8H5NO2

505455 1H-Indole-2,3-dione

821

C8H5NO2

460107 1H-Isoindole-1,3(2H)-dione

822

C8H5N3

536536 3-Amino-1,2-benzenedicarbonitrile

823

C8H6

182188 Ethynylbenzene

824

C8H6F2

474474 1,2-Difluorobenzene – ethyne (1/1)

825

C8H6F15NOSi

467016 N-Methyl-N-[[tris(1,1,2,2,2-pentafluoroethyl)silyl]oxy]methanamine

826

C8H7F

411973 Fluorobenzene – ethyne (1/1)

827

C8H7NO2

904128 1-Ethenyl-3-nitrobenzene

828

C8H8

414951 Benzene – ethyne (1/1)

829

C8H8BN

487906 [1,2]Azaborino[1,2-a][1,2]azaborine

830

C8H8O

210585 Ethynylbenzene – water (1/1)

831

C8H8S

211361 Ethynylbenzene – hydrogen sulfide (1/1)

832

C8H9NO2

513732 2-Methoxybenzamide

833

C8H10

437177 1,2-Dimethylbenzene

834

C8H10O2

211508 1,2-Dimethoxybenzene

835

C8H10O2

211300 1,3-Dimethoxybenzene

836

C8H11N

925394 N,N-Dimethylbenzenamine

837

C8H12

141077 1,1ꞌ-Ethenylidenebiscyclopropane

838

C8H12

198832 Ethynylcyclohexane

839

C8H13NO

214676 8-Methyl-8-azabicyclo[3.2.1]octan-3-one

840

C8H13NO

208922 Benzeneethanamine – water (1/1)

841

C8H14F3N

418427 7-Azabicyclo[2.2.2]octane – trifluoromethane (1/1)

842

C8H16

539298 1,1,3,3-Tetramethylcyclobutane

843

C8H18O5

497672 1,4,7,10-Tetraoxacyclododecane – water (1/1)

844

C8H20O6

497856 1,4,7,10-Tetraoxacyclododecane – water (1/2)

845

C8H24B4N4S2

362704 N2,N2,N3,N3,N5,N5,N6,N6-Octamethyl-1,4,2,3,5,6-dithiatetraborinane

846

C9HF11O

385103 2,3,4,5,6-Pentafluoro-α,α-bis(trifluoromethyl)benzenemethanol

847

C9H3F9

420109 1,3,5-Tris(trifluoromethyl)benzene

848

C9H7N

193271 Quinoline

849

C9H8O

934410 (2E)-3-Phenylpropenal

850

C9H9Cl2N3

572627 N-(2,6-Dichlorophenyl)imidazolidin-2-imine

851

C9H10

127869 2,3-Dihydro-1H-indene

852

C9H10N2

131938 4-(Dimethylamino)benzonitrile

853

C9H10O

371694 1-(2-Methylphenyl)ethanone

854

C9H13N3Si

363067 1-(Trimethylsilyl)-1H-benzotriazole

855

C9H14O

443400 6,6-Dimethylbicyclo[3.3.1]heptan-2-one

856

C9H15NO

375539 9-Methyl-9-azabicyclo[3.3.1]nonan-3-one

857

C9H20Si

464801 1-(1,1-Dimethylethyl)silacyclohexane

Compound Index

921

858

C9H24Br4Si4

464604 Methanetetrayltetrakis(bromodimethylsilane)

859

C9H24Cl4Si4

464432 Methanetetrayltetrakis(chlorodimethylsilane)

860

C9H24F4Si4

464259 Methanetetrayltetrakis(fluorodimethylsilane)

861

C9H28Si4

464051 Methanetetrayltetrakis(dimethylsilane)

862

C10Cl10Fe

368272 1,1ꞌ,2,2ꞌ,3,3ꞌ,4,4ꞌ,5,5ꞌ-Decachloroferrocene

863

C10H5F5Fe

465533 1,2,3,4,5-Pentafluoroferrocene

864

C10H6Cl2O4S2

539121 1,5-Naphthalenedisulfonyl dichloride

865

C10H7ClO2S

343984 1-Naphthalenesulfonyl chloride

866

C10H7ClO2S

422140 2-Naphthalenesulfonyl chloride

867

C10H7FO2S

419541 2-Naphthalenesulfonyl fluoride

868

C10H9F7O

341500 Benzene – 1,1,1,3,3,3-hexafluoro-2-(fluoromethoxy)propane (1/1)

869

C10H9NO2S

447540 1-Naphthalenesulfonamide

870

C10H9NO2S

447355 2-Naphthalenesulfonamide

871

C10H10O2

381282 (2Z)-3-Hydroxy-1-phenyl-2-buten-1-one

872

C10H10O2

382358 (3Z)-4-Hydroxy-4-phenyl-3-buten-2-one

873

C10H11F3

460680 2,3-Dihydro-1H-indene – trifluoromethane (1/1)

874

C10H12N2

152147 1H-Indole-3-ethanamine

875

C10H14N2

216424 3-(2-Piperidinyl)pyridine

876

C10H14O

541325 6,6-Dimethylbicyclo[3.1.1]hept-2-ene-2-carboxaldehyde

877

C10H14O

359804 (1R,5R)-4,6,6-Trimethylbicyclo[3.1.1]hept-3-en-2-one

878

C10H14O4Zn

750995 Bis(2,4-pentanedionato-κO,κO’)zinc

879

C10H16

483483 2,2-Dimethyl-3-methylenebicyclo[2.2.1]heptene

880

C10H16

663598 2,6,6-Trimethylbicyclo[3.1.1]hept-2-ene

881

C10H16

507006 6,6-Dimethyl-2-methylenebicyclo[3.3.1]heptane

882

C10H16O

494368 1,3,3-Trimethylbicyclo[2.2.1]heptan-2-one

883

C10H17B

316921 3-Methyl-1-boratricyclo[3.3.1.13,7]decane

884

C10H17P

387225 Tricyclo[3.3.1.13,7]dec-1-ylphosphine

885

C10H18ClP3

886

C10H18Cu2O4

384376 3-Chloro-2,4-bis(1,1-dimethylethyl)-1,3,5-triphosphatricyclo[2.1.0.02,5]pentane 214340 Bis[µ-2,2-dimethylpropanato-O:O’]dicopper

887

C10H18O

486737 1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octane

888

C10H18O2

451319 1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one – water (1/1)

889

C10H20O3

451485 1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one – water (1/2)

890

C10H22O4

485765 1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one – water (1/3)

891

C10H30Si4

373915 1,1ꞌ,1ꞌꞌ-(Silylmethylidyne)tris[1,1,1-trimethylsilane]

892

C11H8O2

518346 2-Methyl-1,4-naphthalenedione

893

C11H12N2O

378900 1,2-Dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one

894

C11H12N2O2

210456 L-Tryptophan

895

C11H15ClSi

538935 1-Chloro-1-phenylsilacyclohexane

896

C11H15FSi

538740 1-Fluoro-1-phenylsilacyclohexane

897

C11H15N

540586 1-Phenylpiperidine

898

C11H16OSi

466449 3-Methyl-3-phenyl-1-oxa-3-silacyclohexane

899

C11H16Si

418010 1-Phenylsilacyclohexane

922

Compound Index

900

C11H20O2

144866 (4Z)-5-Hydroxy-2,2,6,6-tetramethyl-4-hepten-3-one

901

C11H21N

467599 1-Cyclohexylpiperidine

902

C11H30Br2Si4

466093 [Bis(bromodimethylsilyl)methylene]bis[trimethylsilane]

903

C11H30Cl2Si4

465926 [Bis(chlorodimethylsilyl)methylene]bis[trimethylsilane]

904

C11H32Si4

465730 [Bis(dimethylsilyl)methylene]bis[trimethylsilane]

905

C12H10

208436 1,2-Dihydroacenaphthylene

906

C12H12O

517779 1,2-Dihydroacenaphthylene – water (1/1)

907

C12H12O2

129586 Phenol dimer

908

C12H12Ti

152055 (η7-Cycloheptatrienylium)(η5-2,4-cyclopentadien-1-yl)titanium

909

C12H14N2O2

515960 2-Oxo-4-phenyl-1-pyrrolidineacetamide

910

C12H14O2

551251 1,2-Dihydroacenaphthylene – water (1/2)

911

C12H14O3

211000 (2R,3R)-rel-3-Methyl-3-phenyl-2-oxiranecarboxylic acid ethyl ester

912

C12H14O3

305433 (2R,3S)-rel-3-Methyl-3-phenyl-2-oxiranecarboxylic acid ethyl ester

913

C12H16O3

528991 1,2-Dihydroacenaphthylene – water (1/3)

914

C12H18N2O2Zn

356433 [4,4ꞌ -[1,2-Ethanediyldi(nitrilo-κN)]bis[2-pentanato-κO]]zinc

915

C12H18O

210376 2,6-Bis(1-methylethyl)phenol

916

C12H18Si

540193 1-Methyl-1-phenylsilacyclohexane

917

C12H18Si3

467225 (1α,3α,5α)-1,3,5-Triethynyl-1,3,5-trimethyl-1,3,5-trisilacyclohexane

918

C12H30Ga2O2

381823 Bis[µ-(2-methyl-2-propanolato)]tetramethyldigallium

919

C12H38Si6

517976 1,1,1,4,4,4-Hexamethyl-2,3-bis(trimethylsilyl)tetrasilane

920

C14H42Si6

518162 1,1,1,2,3,4,4,4-Octamethyl-2,3-bis(trimethylsilyl)tetrasilane

921

C15H3F18LaO6

211489 Tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato-κO2,κO4)lanthanum

922

C15H3F18NdO6

211662 Tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato-κO2,κO4)neodymium

923

C15H3F18O6Sm

211834 Tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato-κO2,κO4)samarium

924

C15H11F5

538578 1,2,3,4,5-Pentafluoro-6-(3-phenylpropyl)benzene

925

C15H12O2

385489 (2Z)-3-Hydroxy-1,3-diphenyl-2-propen-1-one

926

C15H21CoO6

343622 Tris(2,4-pentanedionato-κO,κO’)cobalt

927

C15H21CrO6

343818 Tris(2,4-pentanedionato-κO,κO')chromium

928

C15H21MnO6

540027 Tris(2,4-pentanedionato-κO2,κO4)manganese

929

C16H14CuN2O2

930

C16H14N2O2Zn

931

C16H15F5Si

364250 [[2,2ꞌ-[1,2-Ethanediylbis(nitrilo-κN)methylidyne]]bis[phenolatoκO]copper 362323 [[2,2ꞌ-[1,2-Ethanediylbis(nitrilo-κN)methylidyne]]bis[phenolatoκO]]zinc 538228 1-[2-(Dimethylphenylsilyl)ethyl]-2,3,4,5,6-pentafluorobenzene

932

C16H15F5Si

538394 1-[Dimethyl(2-phenylethyl)silyl]-2,3,4,5,6-pentafluorobenzene

933

C16H24O12Si8

934

C16H38N4W

384757 1,3,5,7,9,11,13,15-Octaethenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane 362519 Bis[(1,1-dimethylethyl)imino]bis(2-methylpropanaminato)tungsten

935

C16N16S4Zn

936

C18BF15

539471 [25H,27H-Tetrakis[1,2,5]thiadiazolo[3,4-b:3',4'-g:3'',4''-l:3''',4'''q]porphyrazin-14-SIV-ato-κN25,κN26,κN27,κN28]zinc 573175 Tris(2,3,4,5,6-pentafluorophenyl)borane

937

C18H15Bi

382703 Triphenylbismuthine

938

C18H16Si

151937 1,1ꞌ,1ꞌꞌ-Silylidynetrisbenzene

939

C18H18O3

398368 Phenol trimer

Compound Index

923

356605 1,3,5,7,9,11-Hexakis[(trimethylsilyl)oxy]tetracyclo[5.5.1.13,11.15,9]hexasiloxane 367195 1ꞌ,3ꞌ-Dihydro-1ꞌ,3ꞌ,3ꞌ-trimethyl-6-nitrospiro[2H-1-benzopyran-2,2ꞌ[2H]indole] 367029 (6Z)-6[(2Z)-2-(1,3-Dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)ethylidene]-4-nitro-2,4-cyclohexadien-1-one

940

C18H54O15Si12

941

C19H18N2O3

942

C19H18N2O3

943

C20H10

145598 Dibenzo[ghi,mno]fluoranthene

944

C20H12O

541509 Dibenzo[ghi,mno]fluoranthene – water (1/1)

945

C20H14CuN2O2

946

C20H14N2NiO2

947

C20H14N2O2Zn

366310 [[2,2ꞌ-[1,2-Phenylenebis[(nitrile-κN)methylidyne]bis[phenolato-κO]]copper 326521 [[2,2ꞌ-[1,2-Phenylenebis[(nitrile-κN)methylidyne]bis[phenolato-κO]]nickel 213970 [[2,2ꞌ-[1,2-Phenylenebis[(nitrilo-κN)methylidyne]bis[phenolato-κO]]zinc

948

C21BF21

573360 Tris[2,3,5,6-tetrafluoro-4-(trifluoromethyl)phenyl]borane

949

C24H26Si2

540943 1,8-Bis[2-(trimethylsilyl)ethynyl]anthracene

950

C24H72O20Si16

384573 Octacis[(trimethylsilyl)oxy]pentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane

951

C26H34O2

548500 8,8'-Dioxa-1,1'-bi(pentacyclo[7.3.1.14,12.02,7.06,11]tetradecane)

952

C28H28CuN4

953

C28H28N4Sn

954

C28H38

955

C30H15N15S3

956

C30H18

367380 [2,3,7,8,12,13,17,18-Octamethyl-21H,23H-porphinatokN21,kN22,kN23,kN24]copper 213422 [2,3,7,8,12,13,17,18-Octamethyl-21H,23H-porphinatokN21,kN22,kN23,kN24]tin 548676 Hexadecahydro-1,1'(2H,2'H)-bi-3,5,1,7[1,2,3,4]butanetetraylnaphthalene 343449 7,10:19,22:31,34-Triepithio-5,36:12,17:24,29-triiminotribenzo[f,p,z][1,2,4,9,11,12,14,19,21,22,24,29]dodecaazacyclotriacontine 466820 1,8-Bis(2-phenylethynyl)anthracene

957

C32H16CuN8

124610 [29H,31H-Phthalocyaninato-κN29, κN30, κN31, κN32]copper

958

C32H16N8Ni

133514 [29H,31H-Phthalocyaninato-κN29, κN30, κN31, κN32]nickel

959

C32H16N8OTi

363264 Oxo[29H,31H-phthalocyaninato-κN29, κN30, κN31, κN32]titanium

960

C32H16N8OV

513209 Oxo[29H,31H-phthalocyaninato-κN29, κN30, κN31, κN32]vanadium

961

C32H36CuN4

962

C32H36N4Zn

963

C33H24IrN3

447160 [2,8,12,18-Tetraethyl-3,7,13,17-tetramethyl-21H,23H-porphinatoκN21,κN22,κN23,κN24]copper 412865 [2,8,12,18-Tetraethyl-3,7,13,17-tetramethyl-21H,23H-porphinatoκN21,κN22,κN23,κN24]zinc 371880 Tris[2-(2-pyridinyl-κN)phenyl-κC]iridium

964

C33H57AlO6

150351 Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO3, κO5]aluminum

965

C33H57CoO6

515774 Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO, κO’)cobalt

966

C33H57CrO6

515589 Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO, κO')chromium

967

C33H57InO6

147948 Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO, κO')indium

968

C33H57O6Tm

413260 Tris(2,2,6,6-tetramethyl-3,5-heptanedionato-κO3, κO5)thulium

969

C42H39N15S3

970

C48H40O12Si8

971

C48H48CuN8

364630 2,14,26-Tris(1,1-dimethylethyl)-7,10:19,22:31,34-triepithio5,36:12,17:24,29-triimino[f,p,z][1,2,4,9,11,12,14,19,21,22,24,29]dodecaazacyclotricontine 371516 1,3,5,7,9,11,13,15-Octaphenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane 414219 [2,9,16,23-Tetrakis(1,1-dimethylethyl)-29H,31H-phthalocyaninatoκN29,κN30,κN31,κN32]copper

972

C72H32F24MgN8 422858 [2,3,7,8,12,13,17,18-Octakis[3-(trifluoromethyl)phenyl]-21H,23Hporphyrazinato-κN21,κN22,κN23,κN24]magnesium

924

Compound Index

51

ClCuH2O

215476 Copper(I) chloride – water (1/1)

52

ClCuH2S

213110 Copper(I) chloride – hydrogen sulfide (1/1)

53

ClCuH3N

453990 Copper(I) chloride – ammonia (1/1)

54

ClHZn

208682 Chlorohydrozinc

55

ClH2NaO

125110 Sodium chloride – water (1/1)

56

ClH3Si

190190 Chlorosilane

57

ClH4NaO2

139820 Sodium chloride – water (1/2)

58

ClH6NaO3

139647 Sodium chloride – water (1/3)

59

Cl2H4O

216239 Hydrogen chloride – water (2/1)

60

Cl2OS

607379 Thionyl chloride

61

Cl2V

102469 Vanadium(II) chloride

62

Cl3Er

146116 Erbium(III) chloride

63

Cl3Fe

770005 Iron(III) chloride

64

Cl3V

367910 Vanadium(III) chloride

65

Cl3Yb

361511 Ytterbium(III) chloride

66

Cl4Te

592061 Tellurium(IV) chloride

67

Cl6Fe2

253628 Di-µ-chlorotetrachlorodiiron

68

CrF2

105933 Chromium(II) fluoride

69

CrH2

210966 (Dihydrogen-κH,κH')chromium (1+) ion

70

CuFH2

379249 Copper(I) fluoride – dihydrogen (1/1)

71

CuFH3N

489334 Copper(I) fluoride – ammonia (1/1)

72

CuHS

152018 Copper hydrogen sulfide

73

CuH2IS

500969 Copper(I) iodide – hydrogen sulfide (1/1)

74

CuH3IN

489162 Copper(I) iodide – ammonia (1/1)

75

DyI3

216590 Dysprosium(III) iodide

76

Dy2I6

370789 Di-µ-iodotetraiododidysprosium

77

ErI3

216393 Erbium(III) iodide

78

FH2

436316 Fluoronium

79

F2N3OP

466277 Phosphorazidic difluoride

80

F2N3P

387410 Phosphorazidous difluoride

81

F2Na2

746515 Di-µ-fluorodisodium

82

FH3Si

133409 Fluorosilane

83

F3H3

142861 Hydrogen fluoride trimer

84

F3N

196598 Trifluoroamine

85

F3P

933660 Trifluorophosphine

86

F4P2S

916047 Thiophosphorous tetrafluoride

87

F4Te

208485 Tellurium(IV) fluoride

88

F6H3NS

457312 Sulfur hexafluoride – ammonia (1/1)

89

F10NS2

572234 Bis(pentafluoro-λ6-sulfanyl)amino

90

F15NS3

572420 1,1,1,1,1-Pentafluoro-N,N-bis(pentafluoro-λ6-sulfanyl) -λ6-sulfanamine

91

FeI2

105877 Iron(II) iodide

92

Fe2I4

554646 Di-µ-iododiiododiiron

93

GdI3

235278 Gadolinium(III) iodide

Compound Index

925

94

HISi

136196 Iodosilylene

95

HKS

360563 Potasium hydrogen sulfide

96

HNO

136067 Nitrosyl hydride

97

HNOS

471320 Thionitrous acid

98

HNO2

402835 Hydroperoxyimidogen

99

HNO3

578183 Nitric acid

100

HNSi

139487 Iminosilylene

101

HNSi2

408981 (Silylidyneamino)silylidyne

102

HN3

964414 Hydrazoic acid

103

HOSi

148933 Hydroxysilylidyne

104

HOY

359238 Yttrium monohydroxide

105

HOZn

208553 Zinc monohydroxide

106

HO2S

340588 Sulfur hydroxide oxide

107

HO3

152368 Hydrotrioxy

108

HPS

209328 Thioxophosphine

109

HPSi

211914 Phosphinidenesilylene

110

HSZn

322779 Zinc hydrogen sulfide

111

H 2I 2

144971 Hydrogen iodide dimer

112

H2I2Si

152123 Diiodosilane

113

H2Mg

211533 (Dihydrogen-κH,κH')magnesium (1+) ion

114

H2Mn

211324 (Dihydrogen-κH,κH')manganese (1+) ion

115

H 2N 2O

471122 Nitrosamine

116

H 2N 2O

119821 Water – dinitrogen (1/1)

117

H2Na

211871 Sodium (1+)ion – dihydrogen (1/1)

118

H2Ne

745402 Dihydrogen – neon (1/1)

119

H2NeO

215704 Water – neon (1/1)

120

H2OS

147752 Hydrogen thioperoxide

121

H2O2Si

474831 Dihydroxysilylene

122

H2O2Si

475016 Dioxasilacyclopropane

123

H2SSi

211270 Thioxosilane

124

H2Si

360354 Silylene

125

H2Xe

128393 Dihydrogen – xenon (1/1)

126

H2Zn

211140 (Dihydrogen-κH,κH')zinc (1+) ion

127

H3NSi2

408803 (Silylimino)silylene

128

H 3S

310283 Sulfonium

129

H6OSi

141391 Silane – water (1/1)

130

H10O15Si10

362102 Hexacyclo[9.9.13,9.15,17.17,15.113,19]decasiloxane

131

H12O6

139309 Water hexamer

132

H14O7

352342 Water heptamer

133

H18O9

352170 Water nonamer

134

H20O10

410651 Water decamer

135

HeN2O

150511 Dinitrogen monoxide – helium (1/1)

136

HoI3

146602 Holmium(III) iodide

926

Compound Index

137

I2Na2

161979 Di-µ-iododisodium

138

I3Pr

506753 Praseodymium(III) iodide

139

I3Tb

213201 Terbium(III) iodide

140

KrN2O

141089 Dinitrogen monoxide – krypton (1/1)

141

KrO3S

385428 Sulfur trioxide – krypton (1/1)

142

N2OXe

140900 Dinitrogen monoxide – xenon (1/1)

143

N 2O 4

535202 Nitrosyl nitrate

144

N2S2

401931 1λ4δ2-1,3,2,4-Dithiadiazete

145

N 8O 4

215882 Dinitrogen monoxide tetramer

146

OSSi

216633 Silicon oxide sulfide

147

O 2S

551982 Sulfur dioxide

148

O2S2

426704 (Z)-1λ4,2λ4-Disulfene-1,2-dione

149

O3SXe

429245 Sulfur trioxide – xenon (1/1)

150

O4Os

851468 Osmium tetroxide

151

O6Sb4

529385 2,4,6,8,9,10-Hexaoxa-1,3,5,7-tetrastibatricyclo[3.3.1.13,7]decane

152

P4

988018 Tetraphosphorous

153

SSi2

209826 Thiadisilacycloprop-2-yne

154

S2Si

332275 Dithiasilacyclopro-3-ylidene