Ethene thiol: A vibrational analysis

Almond, V.; Charles, S.W.; Macdonald, John N.; Owen, Noel L.

doi:10.1016/0022-2860(83)90094-7

Cited by 24 publications

(22 citation statements)

References 17 publications

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“…Experimental studies on vinyl mercaptan are limited. Photoelectron (Chin et al 1994) and low-resolution vibrational spectra (Almond et al 1977(Almond et al , 1983 have been reported, while pure rotational spectra of the two isomers in the ground and several excited vibrational states have only been measured up to 50 GHz (Almond et al 1977;Tanimoto & Saito 1977;. Isotopic investigations of the microwave spectra of the SD isotopologues 1 (Tanimoto & Saito 1977;, and extensive studies of deuterated variants of the syn isomer (Almond et al 1985) that followed, enabled a determination of a partial geometry; owing to the absence of experimental data for isotopic species involving substitution at any of the three heavy atoms, a complete structure has not been reported.…”

Section: Syn Antimentioning

confidence: 99%

“…Vinyl mercaptan exists in the gas phase in two distinct rotameric forms, the planar syn and quasi-planar anti isomers (Fig. 1), with the former only slightly more stable than the latter by about 0.6 kJ/mol (Almond et al 1983(Almond et al , 1985Plant et al 1992), which yields a syn/anti ratio at room temperature of about 1.2. It is worth noting that while the equilibrium structure of the anti isomer is non-planar, with a calculated SH torsional angle of about 130-150 • , the barrier to linearity (0.14 kJ/mol) is small compared to the zero-point vibration, which results in a vibrationally-averaged planar structure Almond et al 1985).…”

Section: Introductionmentioning

confidence: 99%

“…It is worth noting that while the equilibrium structure of the anti isomer is non-planar, with a calculated SH torsional angle of about 130-150 • , the barrier to linearity (0.14 kJ/mol) is small compared to the zero-point vibration, which results in a vibrationally-averaged planar structure Almond et al 1985). As a consequence, both isomers can be considered as belonging to the C s point group symmetry (Almond et al 1983).…”

Section: Introductionmentioning

confidence: 99%

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Submillimeter spectroscopy and astronomical searches of vinyl mercaptan, C₂H₃SH

Martin‐Drumel

Lee

Беллоче

et al. 2019

A&A

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Context. New laboratory investigations of the rotational spectrum of postulated astronomical species are essential to support the assignment and analysis of current astronomical surveys. In particular, considerable interest surrounds sulfur analogs of oxygencontaining interstellar molecules and their isomers. Aims. To enable reliable interstellar searches of vinyl mercaptan, the sulfur-containing analog to the astronomical species vinyl alcohol, we have investigated its pure rotational spectrum at millimeter wavelengths. Methods. We have extended the pure rotational investigation of the two isomers syn and anti vinyl mercaptan to the millimeter domain using a frequency-multiplication spectrometer. The species were produced by a radiofrequency discharge in 1,2-ethanedithiol. Additional transitions have been re-measured in the centimeter band using Fourier-transform microwave spectroscopy to better determine rest frequencies of transitions with low-J and low-K a values. Experimental investigations were supported by quantum chemical calculations on the energetics of both the [C 2 ,H 4 ,S] and [C 2 ,H 4 ,O] isomeric families. Interstellar searches for both syn and anti vinyl mercaptan as well as vinyl alcohol were performed in the EMoCA (Exploring Molecular Complexity with ALMA) spectral line survey carried out toward Sagittarius (Sgr) B2(N2) with the Atacama Large Millimeter/submillimeter Array (ALMA). Results. Highly accurate experimental frequencies (to better than 100 kHz accuracy) for both syn and anti isomers of vinyl mercaptan have been measured up to 250 GHz; these deviate considerably from predictions based on extrapolation of previous microwave measurements. Reliable frequency predictions of the astronomically most interesting millimeter-wave lines for these two species can now be derived from the best-fit spectroscopic constants. From the energetic investigations, the four lowest singlet isomers of the [C 2 ,H 4 ,S] family are calculated to be nearly isoenergetic, which makes this family a fairly unique test bed for assessing possible reaction pathways. Upper limits for the column density of syn and anti vinyl mercaptan are derived toward the extremely molecule-rich star-forming region Sgr B2(N2) enabling comparison with selected complex organic molecules.

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Section: Syn Antimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Submillimeter spectroscopy and astronomical searches of vinyl mercaptan, C₂H₃SH

Martin‐Drumel

Lee

Беллоче

et al. 2019

A&A

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“…It has been shown experimentally that H 2 S and acetylene are major and minor products, respectively, of the thermal decomposition of thiirane. , Ultraviolet photolysis of a mixture of H 2 S and acetylene is actually used for the preparation of THI, ,, but it is unlikely that the fragmentation occurs directly without any intermediate. One reasonable hypothesis is that an intermediate biradical, similar to I2′, is formed upon the transfer of a hydrogen atom from one of the CH 2 residues to the sulfur atom.…”

Section: Resultsmentioning

confidence: 99%

“…Being the simplest compound containing a SH group adjacent to a CC double bond, VTH has been used as a model system for theoretical investigations on the π-donating ability of heteroatoms and on the importance of σ conjugative interaction in rotational isomerism . The conformation of this molecule, especially concerning internal rotation around the C–S bond, was studied experimentally and theoretically several times. − Microwave and infrared spectroscopic data suggest that VTH exists in the planar syn (VTHs) and nearly planar anti (VTHa) conformations, with the syn conformer being the predominant species. − Planar trans VTH is actually a transition state separating two equivalent VTHa conformers. VTH can be customarily produced by thermolysis of thiirane (THI) under reduced pressure in a flow system .…”

Section: Introductionmentioning

confidence: 99%

Isomerization and Fragmentation Reactions on the [C₂SH₄] Potential Energy Surface: The Metastable Thione S-Methylide Isomer

et al. 2021

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Thione S-methylide, parent species of the thiocarbonyl ylide family, is a 1,3dipolar species on the [C 2 SH 4 ] potential energy surface, not so much studied as its isomers, thiirane, vinyl thiol, and thioacetaldehyde. The conrotatory ring-closure reaction toward thiirane was studied in the 90s, but no complete analysis of the potential energy surface is available. In this paper, we report a computational study of the reaction scheme linking all species. We employed several computational methods (density functional theory, CCSD(T) composite schemes, and CASSCF/CASPT2 multireference procedures) to find the best description of thione S-methylide, its isomers, and transition states. The barrier from thiirane to thione Smethylide amounts to 52.2 kcal mol −1 (against 17.6 kcal mol −1 for the direct one), explaining why thiocarbonyl ylides cannot be prepared from thiiranes. Conversion of thiirane to vinyl thiol implies a large barrier, supporting why the reaction has been observed only at high temperatures. Fragmentations of thiirane to S( 3 P) or S( 1 D) and ethylene as well as decomposition to hydrogen sulfide plus acetylene were also explored. Triplet and singlet open-shell species were identified as intermediates in the fragmentations, with energies lower than the transition state between thiirane and vinyl thiol, explaining the preference of the latter at low temperatures.

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