865-36-1

Upstream product

• 556-64-9 methyl thiocyanate 
• 530-48-3 1,1-Diphenylethylene 
• 14160-11-3 2-methyl-3-thioxo-2,3-dihydro-1H-isoindol-1-one 
• 287-53-6 1,3-Dithietan 
• 71870-75-2 1,3-dithiane-5,5-d2 
• 6008-60-2 2-Dicyanmethylen-1,3-dithietan 
• 5813-48-9 Methanesulfenyl chloride 
• 10152-76-8 allylmethyl sulfide 
• 5650-74-8 5-methyldihydrothiophen-2(3H)-one 
• 13882-12-7 S-methyl methanethiosulfinate 
• 431-47-0 trifluoroacetic acid-methyl ester 
• 71928-47-7 CH₂S^(1-) 
• 383-63-1 ethyl trifluoroacetate, 
• 17302-63-5 methanethiolate 

Downstream Products

• 10019-24-6 1,1,2,2-tetrakis(4-methoxyphenyl)ethene 
• 126797-41-9 (3aS,4aR,7R,8aR,9S,9aR)-9-Methoxy-7-phenyl-hexahydro-[1,3]dioxolo[4',5':5,6]pyrano[3,2-d][1,3]dioxine-2-thione 
• 126797-40-8 (3aR,4aR,7R,8aR,9S,9aR)-9-Methoxy-7-phenyl-hexahydro-[1,3]dioxolo[4',5':5,6]pyrano[3,2-d][1,3]dioxine-2-thione 
• 89000-82-8 1,2-O-thiocarbonate-3,5-di-O-benzyl-α/β-D-xylofuranose 
• 137812-07-8 4-methoxy-2H-thiopyran-6(3H,6H)-one 

Relevant academic research and scientific papers

Thermal Decomposition Mechanism for Ethanethiol

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

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

Thermal reactions of regioisomeric 1,2,4-trithiolane s-oxides

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.

Reaction of methylidyne CH(X2π) radical with CH4 and H2S: Overall rate constant and absolute atomic hydrogen production

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].

Thioformaldehyde S-sulfide (Thiosulfine)

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.

Dissociative photoionization of CH3SSCH3 in the region of ～8-25 eV

The dissociative photoionization of CH3SSCH3 has been investigated in the photon energy range of ～8-25 eV with a molecular beam/photoionization mass spectrometry/threshold photoelectron spectrometry system using synchrotron radiation as an ionization source. For dissociation above photon energy of 11.5 eV, six fragment ions of CH3+, C2H3+, SH3+, HCS+, S2+, and CH2S2+ were reported for the first time. The photoionization efficiency spectra for the parent ion and for 12 observed fragment ions, CH3+, C2H3+, SH3+, HCS+, CH2S+, CH2SH+, CH3SH+, CH3SH2+, CH3SCH2+, S2+, CH2S2+, and CH2S2H+, were measured; their branching ratios as a function of photon energy were derived. Ionization energy of 8.20±0.04eV for CH3SSCH3 and the appearance energy for each fragment ion were determined from the onsets of the photoionization efficiency spectra. Based on the appearance energy and existing thermochemical data, plausible structures of the fragment ions and their neutral counterparts are proposed. Fragmentation mechanisms that involve H migration and structural rearrangement in the dissociative photoionization processes are discussed.

Photochemistry of Phthaloylcsteine, its methyl ester and C-unprotected S-Alkyl derivatives

N-Phthaloyl cysteine derivatives 1a-d were photochemically transformed by elimination, decarboxylation, and via electron transfer cyclization to the products 2,3,4 and 6-8. The spin selectivities of the singlet and triplet pathways were investigated in acetonitrile and acetone . The excited singlets were prone to elimination and γ-H abstraction (e.g. formation of 5) whereas the triplets cyclized to thiazinoisoindoles. This behavior can be correlated with efficiencies of forward and return electron transfer stepsversus homolytic hydrogen abstraction as exemplified for the cysteine substrate.

Electron transfer as a possible initial step in nucleophilic addition elimination reactions between (radical) anions and carbonyl compounds in the gas phase

The reactions of the HO-, CH3S-, CH2S- and CH2=C(CH3)-CH2- ions with three ketones (CF3COR; R=CH3, CF3, C6H5) and three esters of trifluoroacetic acid (CF3CO2R; R=CH3, C2H5 and C6H5) have been studied with use of Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry. All four negative ions react exclusively by proton transfer with CF3COCH3. With the other substrates, the HO- ion reacts by various pathways, such as proton transfer, SN2 substitution, E2 elimination and attack on the carbonyl group. The CH3S- ion is unreactive towards CF3COC6H5 but is able to react by hydride transfer, SN2, E2 and/or carbonyl attack with the remaining neutral species. The CH2S- radical anion reacts by electron transfer to afford stable molecular radical anions of CF3COCF3 and CF3COC6H5, whereas the main reaction with the two esters, CF3CO2CH3 and CF3CO2C2H5, is dissociative electron transfer leading to CF3CO2- and CF3- ions. The CH2=C(CH3)-CH2- anion displays a more complex reactivity pattern involving electron transfer, SN2, E2 as well as attack on the carbonyl group. Direct evidence for the occurrence of electron transfer as the initial step in an overall BAC2 type process has not been obtained for the systems studied. The reaction of the CH2S- ion with CF3CO2C6H5 was observed, however, to yield exclusively a CF3COCHS-. radical anion. Based upon the absence of a BAC2 process in the reaction of CH2S- with the methyl and ethyl esters of trifluoroacetic acid in combination with the facile occurrence of electron transfer from this radical anion, it is suggested that the CF3COCHS-. ion is formed by an initial electron transfer followed by coupling between the CH2S molecule and the CF3CO2C6H5- radical anion and subsequent loss of C6H5OH from the collision complex.

Sulfenic acids in the gas phase: A photoelectron study

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.

Thermal decomposition of methylated γ-thiobutyrolactones: A photoelectron spectroscopic study

The thermal decomposition of γ-thiovalerolactone, α-methyl-γ-thiobutyrolactone and β-methyl-γ- thiobutyrolactone has been studied in a gaseous flow system, by monitoring the changes in the photoelectron spectra recorded during the course of the reactions. Three modes of decomposition were observed, two involve loss of carbon monoxide (decarbonylation) and one involves loss of carbonyl sulfide (decarboxylation). The decarbonylation reaction producing an olefin and a thioaldehyde and the decarboxylation producing an olefin are similar to those observed for the unsubstituted thiobutyrolactone. The third reaction, observed only in the methylated compounds, is decarbonylation with the formation of hydrogen sulfide and butadiene. It is proposed that the last reaction can be attributed to the relatively facile elimination reaction of a butenethiol intermediate.