30699-99-1Relevant articles and documents
Thermal reactions of regioisomeric 1,2,4-trithiolane s-oxides
Mloston, Grzegorz,Romanski, Jaroslaw,McKee, Michael L.,Reisenauer, Hans Peter,Schreiner, Peter R.
, p. 2132 - 2137 (2010)
The products of the gas-phase pyrolysis of two regioisomeric 1,2,4-trithiolane S-oxides were collected in an argon matrix at 1OK and studied by means of spectroscopic as well as computational methods. Whereas the main products of the pyrolysis of the symmetrical S-oxide were identified as thioformaldehyde S-oxide and thioformaldehyde S-sulfide, the non-symmetrical S-oxide gave predominantly dithioformic acid, which exists as a mixture of s-cis and s-trans conformers. We present a rationalization of the reaction pathways including density functional theory computations.
Sulfenic acids in the gas phase: A photoelectron study
Lacombe,Loudet,Banchereau,Simon,Pfister-Guillouzo
, p. 1131 - 1138 (1996)
Thermolysis of methyl methanethiosulfinate and methyl tert-butyl sulfoxide has been studied by photoelectron (PE) spectroscopy. The electronic structure of methanesulfenic acid (1) generated from both compounds has been determined, and the thermal stability of 1 was checked. 1 appears rather stable in the gas phase, giving rise to thioformaldehyde and water at high temperature. Thermolysis of vinyl tert-butyl sulfoxide gives rise to ethanethial S-oxide (6). At the thermolysis onset, sulfine 6 is observed in a mixture with a compound identified as ethenesulfenic acid (4). These results imply either an easy isomerization of 4 to 6, in agreement with previous theoretical evaluations, or an alternative thermolysis pathway of the starting sulfoxide, directly leading to sulfine 6. The obtained PE spectra complement previous microwave and/or mass spectrometry data and provide a further insight in the electronic structure and thermal stability of sulfenic acids 1 and 4. The experimental ionization potentials are compared throughout this study with ab-initio calculated vertical ionization potentials either within Koopmans' approximation or by difference between the ionic and ground state energies.
Reaction of methylidyne CH(X2π) radical with CH4 and H2S: Overall rate constant and absolute atomic hydrogen production
Fleurat-Lessard, Paul,Rayez, Jean-Claude,Bergeat, Astrid,Loison, Jean-Christophe
, p. 87 - 99 (2002)
The CH + CH4 and H2S reactions were studied, at room temperature, in a low-pressure fast-flow reactor. CH (X2π, v = 0) radicals were obtained from the reaction of CHBr3 with potassium atoms. The overall rate constants were found at 330 K to be (0.76 ± 0.20) x 10-10 and (2.8 ± 0.8) x l0-10 cm3 molecule-1 s-1, respectively. The absolute atomic hydrogen productions were determined by resonance fluorescence in the vacuum ultraviolet: H production from the CH + CH4 reaction is 100% and from the CH + H2S reaction is 99-4+1%, the H production from the CH + H2 reaction being the reference. Ab initio studies of the different stationary points relevant to the CH + CH4 reaction have been performed at the CCSD(T)/cc-pVTZ level and comparison is made with experimental results. The experimental results for the CH + H2S reaction is compared with those of a recent theoretical study [Chem. Phys. 242 (1999) 1].
Sub-Doppler spectroscopy of thioformaldehyde: Excited state perturbations and evidence for rotation-induced vibrational mixing in the ground state
Clouthier, Dennis J.,Huang, G.,Adam, A. G.,Merer, A. J.
, p. 7300 - 7310 (1994)
High-resolution intracativity dye laser spectroscopy has been used to obtain sub-Doppler spectra of transitions to 350 rotational levels in the 401 band of the 1A2- 1A1 electronic transition of thioformaldehyde.Ground state combination differences from the sub-Doppler spectra, combined with microwave and infrared data, have been used to improve the ground state rotational and centrifugal distortion constants of H2CS.The upper state shows a remarkable number of perturbations.The largest of these are caused by nearby triplet levels, with matrix elements of 0.05-0.15 cm-1.A particularly clear singlet-triplet avoided crossing in Ka' = 7 has been shown to be caused by interaction with the F1 component of the 3162 vibrational level of the 3A2 state.At least 53percent of the S1 levels show evidence of very small perturbations by high rovibronic levels of the ground state.The number of such perturbations is small at low J, but increases rapidly beyond J=5 such that 40percent-80percent of the observed S1 levels of any given J are perturbed by ground state levels.Model calculations show that the density and J dependence of the number of perturbed levels can be explained if three is extensive rotation-induced mixing of the vibrational levels in the ground state.
FORMATION OF REACTIVE THIOALDEHYDES BY VACUUM GAS-PHASE DEHYDROCYANATION OF THIOCYANOHYDRINS; CHARACTERIZATION BY MS/MS SPECTROMETRY.
Wazneh, L.,Guillemin, J. C.,Guenot, P.,Vallee, Y.,Denis, J. M.
, p. 5899 - 5900 (1988)
Methanethial 2a and ethanethial 2b are obtained by a vacuum gas-phase dehydrocyanation of the corresponding thiocyanohydrins and characterized by mass spectroscopy experiments.
Perturbations in the 1A2 State of Thioformaldehyde Produced by High Vibrational Levels of the Ground State
Fung, K. H.,Ramsay, D. A.
, p. 395 - 397 (1984)
Measurements have been made of the asymmetry doublings in the lines of the rR3 branch of the 401 band of the 1A2- 1A1 system of thioformaldehyde by using the technique of intermodulated fluorescence.Line widths of ca. 5 MHz have been achieved and many small irregular perturbations up to ca. 300 MHz have been observed.These perturbations are not magnetically sensitive and must be caused by high vibrational levels of the ground state.The mixing of ground- and excited-state rovibronic levels produces irregularities in the fluorescence efficiencies of the latter.
COLLISIONAL RELAXATION OF H2CS (A1A2, v'4=1)
Kawasaki, Masahiro,Kasatani, Kazuo,Uchida, Toyohisa,Sato, Hiroyasu
, p. 325 - 328 (1983)
Fluorescence spectra of single vibronic levels of the first excited singlet state of H2CS have been measured under effusive flow conditions as a function of pressure.Weak non-resonance bands grow in with increasing pressure, demonstrating the existence of collisional vibrational relaxation of the 41 level to the 40 level.
Thermal Decomposition Mechanism for Ethanethiol
Vasiliou, AnGayle K.,Anderson, Daniel E.,Cowell, Thomas W.,Kong, Jessica,Melhado, William F.,Phillips, Margaret D.,Whitman, Jared C.
, p. 4953 - 4960 (2017/07/17)
The thermal decomposition of ethanethiol was studied using a 1 mm x 2 cm pulsed silicon carbide microtubular reactor, CH3CH2SH + Δ → Products. Unlike previous studies these experiments were able to identify the initial ethanethiol decomposition products. Ethanethiol was entrained in either an Ar or a He carrier gas, passed through a heated (300-1700 K) SiC microtubular reactor (roughly ≤100 μs residence time) and exited into a vacuum chamber. Within one reactor diameter the gas cools to less than 50 K rotationally, and all reactions cease. The resultant molecular beam was probed by photoionization mass spectroscopy and IR spectroscopy. Ethanethiol was found to undergo unimolecular decomposition by three pathways: CH3CH2SH → (1) CH3CH2 + SH, (2) CH3 + H2C=S, and (3) H2C=CH2 + H2S. The experimental findings are in good agreement with electronic structure calculations. (Chemical Equation Presented).
Gas-phase and matrix-isolation photochemistry of methyl thioglycolate, CH3OC(O)CH2SH: Influence of the presence of molecular oxygen in the photochemical mechanisms
Bava, Yanina B.,Tamone, Luciana M.,Juncal, Luciana C.,Seng, Samantha,Tobón, Yeny A.,Sobanska, Sophie,Picone, A. Lorena,Romano, Rosana M.
, p. 101 - 107 (2017/05/17)
The photochemistry of methyl thioglycolate (MTG), CH3OC(O)CH2SH, in gas phase and in matrix isolation conditions was studied by means of FTIR spectroscopy, and the influence of the presence of molecular oxygen on the photochemical me
Thioformaldehyde S-sulfide (Thiosulfine)
Mlosto, Grzegorz,Romaski, Jaroslaw,Reisenauer, Hans Peter,Maier, Gnther
, p. 393 - 396 (2007/10/03)
Matrix isolation spectroscopy allows the direct identification of ylide 1 and its cyclic isomer 2. They were obtained by pyrolysis of 1,2,4-trithiolane under high vacuum; the cyclic compound forms from 1 by thermal ring closure in a kinetically controlled reaction.
