The Millimeter-Wave Spectrum and Structure of Vinyl Chloride

doi:10.1006/jmsp.1996.0137

Journal of Molecular Spectroscopy

Volume 177, Issue 2, June 1996, Pages 232-239

https://doi.org/10.1006/jmsp.1996.0137 Get rights and content

Abstract

The ground state rotational spectra of[formula]and[formula]have been measured in the millimeter-wave and submillimeter-wave ranges. These new data have been used to improve notably the accuracy of the rotational and centrifugal distortion constants. Finally anab initiostructure has been calculated and a near-equilibrium structure has been estimated using offsets derived empirically.

References (0)

Cited by (18)

Chlorine nuclear quadrupole coupling in chlorodifluoroacetyl chloride: Theory and experiment
2010, Journal of Molecular Spectroscopy
Citation Excerpt :
For calculation of approximate equilibrium molecular structures, Demaison et al. have shown in a series of papers [8–11] that errors inherent in relatively modest ab initio calculations of bond lengths are largely systematic and can be empirically corrected, and that accurate interatomic angles may be obtained at the MP2 level of theory in conjunction with fairly large triple-zeta bases.
A potential energy scan of chlorodifluoroacetyl chloride, ${CF}_{2} Cl$ C(O)Cl, at the MP2/6-311+G(d) level of theory predicts stable gauche and trans conformers, with $E_{gauche} < E_{trans}$ . Ab initio calculations were made of approximate equilibrium structures of these and, on these structures, calculations were made of ³⁵Cl and ³⁷Cl nuclear quadrupole coupling constant tensors. Coupling constants here predicted, as well as rotational constants and molecular dipole moments, are applied to aid analyses of experimental microwave spectra. Chirped pulse Fourier transform microwave spectroscopy has been used to rapidly record the rotational spectra of four isotopologues of the title molecule, ${CClF}_{2} C (O) Cl$ , namely ³⁵Cl³⁵Cl, ³⁵Cl³⁷Cl, ³⁷Cl³⁵Cl, and ³⁷Cl³⁷Cl. Only the gauche conformer was observed under the experimental conditions. For the four isotopologues a total of 464, 219, 197, and 77 transitions have been recorded, respectively. With the exception of the ³⁷Cl³⁷Cl isotopologue sufficient data was available to determine all Cl quadrupole coupling tensors. Comparisons between the theoretical and experimental results are made.
Microwave and high resolution infrared spectra of vinyl chloride, ab initio anharmonic force field and equilibrium structure
2005, Journal of Molecular Spectroscopy
Citation Excerpt :
The experimental data do not permit to determine the constants ϕJK and ϕK. For this reason, they were fixed at zero in the original work [7]. However, they are correlated with the other sextic constants (mainly ΦJK), which makes a comparison with the ab initio constants meaningless.
The quadratic, cubic, and semi-diagonal quartic force field of vinyl chloride has been calculated at the MP2 level of theory employing a basis set of triple-ζ quality. The spectroscopic constants derived from this force field are compared with the experimental values. To make this comparison more complete, the rotational constants of the lowest excited state, v₉ = 1 at 395 cm⁻¹ have been determined by microwave spectroscopy and the ν₁₂ band (around 618 cm⁻¹) has been investigated by high-resolution infrared Fourier transform spectroscopy. The equilibrium structure has been derived from experimental ground state rotational constants and ab initio rovibrational interaction parameters. This semi-experimental structure is in excellent agreement with the ab initio structure calculated at the CCSD(T) level of theory using a basis set of quintuple-ζ quality and a core correlation correction. The experimental mass-dependent r_m structures are also determined and their accuracy is discussed. The recommended equilibrium geometry is: r (CC) = 1.3262(10), r (CCl) = 1.7263(10), r (CH_g) = 1.0784(10), r (CH_c) = 1.0795(10), r (CH_t) = 1.0797(10), ∠(CCCl) = 122.77(10)°, ∠(CCH_g) = 123.86(10)°, ∠(CCH_c) = 121.80(10)°, ∠(CCH_t) = 119.29(10)°.
Infrared and Raman spectra, conformational stability, ab initio calculations and vibrational assignments for trans-3-chloropropenoyl chloride
2000, Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
The infrared (3500–30 cm⁻¹) spectra of gaseous and solid and the Raman (3500–200 cm⁻¹) spectra of the liquid with quantitative depolarization ratios and solid trans-3-chloropropenoyl chloride (trans-ClCHCHCClO) have been recorded. These data indicate that both the anti (carbonyl bond trans to the carbon–carbon double bond) and syn conformers are present in the fluid states but only the anti conformer is present in the crystalline state. The mid-infrared spectra of the sample dissolved in liquid xenon as a function of temperature (−55 to −100°C) have been recorded. Utilizing conformer pairs at 870 and 725 cm⁻¹, 1215 and 1029 cm⁻¹, and 1215 and 1228 cm⁻¹, the enthalpy difference has been determined to be 136±5 cm⁻¹ (389±14 cal mol⁻¹) with the anti conformer the more stable form. Optimized geometries and conformational stabilities were obtained from ab initio calculations at the levels of RHF/6-31G(d), MP2/6-31G(d), MP2/6-311++G(d,p), MP2/6-311++G(2d,2p) and MP2/6-311++G(2df,2pd) with only the latter two calculations predicting the anti rotamer to be the more stable form. The vibrational frequencies, harmonic force constants and infrared intensities were obtained from the MP2/6-31G(d) calculations, whereas the Raman activities and depolarization values were obtained from the RHF/6-31G(d) calculations. The spectra are interpreted in detail and the results are compared with those obtained for some related molecules.
High-lying Rydberg states and ionization energy of vinyl chloride studied by two-photon resonant ionization spectroscopy
2000, Chemical Physics Letters
Citation Excerpt :
The spectroscopy [1–9]and photodissociation dynamics [10–17]of vinyl chloride (C2H3Cl) have been intensively examined in the past decades.
High-lying Rydberg states of jet-cooled vinyl chloride at 9.3–10 eV are investigated using 2+1 resonance-enhanced multiphoton ionization spectroscopy. Four Rydberg series are observed and tentatively assigned as due to the transitions of π→ns, npσ, npπ, and nf Rydberg orbitals associated with quantum defects of 0.94, 0.89, 0.48, and 0.02, respectively. All of the four series converge to the same ionization energy limit corresponding to the ground state of vinyl chloride cation. The adiabatic ionization energy of vinyl chloride is determined to be 80 720±6 cm⁻¹, in excellent agreement with previously reported values.
Terahertz rotational spectra of NH<inf>2</inf>OH in the ground and some low excited vibrational states
2000, Journal of Molecular Structure
Citation Excerpt :
The details of those NAIR and Cologne spectrometers are given elsewhere [6,7]. At the University of Lille, the mmW and sub-mmW spectra in the region from 150 to 500 GHz were observed by a Carcinotron-based spectrometer [8], and those from 500 to 1800 GHz by a laser-side-band spectrometer [9]. Essentially the same procedures were applied in the three laboratories for the production and the handling of the sample in the present study.
The rotational spectra of hydroxylamine, NH₂OH, have been measured for the ground and some excited vibrational states, with high precision in the mmW (millimeter wave) and sub-mmW region, up to 1.8 THz, using BWO based spectrometers and a laser-side-band FIR spectrometer. No tunnel splitting has been observed and it is concluded that the barrier to the tunneling motion is very high. The observed line positions have been analyzed with Watson's S-reduced Hamiltonian with extension to higher order terms up to J¹⁰ order.
Chapter 1 Molecular structure determination from spectroscopic data using scaled moments of inertia
1999, Vibrational Spectra and Structure
This chapter demonstrates the scaled moment of inertia (r^ρ_m) structure method to yield an excellent approximation to the theoretically significant equilibrium (r_e) structure. A practical variant of Watson's r_m procedure, the method requires only the spectroscopic data necessary to perform a complete ground state substitution (r_s) structure determination. The resulting r^ρ_m structure appears to be invariably a more reliable estimate of the true r_e structure than is the r_s structure. For polyatomic molecules, the heavy-atom distance parameters are expected to be within 0.001–0.002 A of the r_e value in most cases. For hydrogen-containing molecules, a special empirical correction is needed to handle the data for the hydrogen isotopomers. This correction ensures that the quality of the heavy-atom parameters remains high, and leads to H-atom parameters of reduced, but useful, accuracy (0.002–0.004 A). The new procedure permits for the first time the practical estimation of reliable near-r_e structures for polyatomic organic molecules from gas-phase spectroscopic ground state rotational constants. Along with gas electron diffraction and modem high-quality ab initio computations, the r^ρ_m methodology provides a reliable new tool for the high-precision structure determination of modest-sized polyatomic organic molecules.

View all citing articles on Scopus

¹: Current address: Institut für Physikalische Chemie, Rheinisch-Westfälische Technische Hochschule, Templergraben 59, D-52056 Aachen, Germany.

View full text

Regular ArticleThe Millimeter-Wave Spectrum and Structure of Vinyl Chloride

Abstract

Regular Article
The Millimeter-Wave Spectrum and Structure of Vinyl Chloride