Computational study on the mechanism and kinetics for reaction of CH 3 SH + H with water vapor

Du, Benni; Zhang, Weichao

doi:10.1016/j.comptc.2017.08.018

Cited by 4 publications

(1 citation statement)

References 37 publications

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“…Chemical (or reactive) desorption is one of the possible desorption processes, which are efficient even at temperatures as low as 10 K (Garrod et al 2007;Dulieu et al 2013;He et al 2017;Wakelam et al 2017;Chuang et al 2018;Oba et al 2018;Nguyen et al 2020). Oba et al (2018) As Reactions (7) and (8) are exothermic, with activation barriers of 5.7 × 10 −2 and 4.0 × 10 −1 eV in the gas phase, respectively (Du & Zhang 2017), these reactions would require quantum tunneling to proceed on cold surfaces at temperatures as low as 10 K. After the formation of CH 3 S and/or CH 2 SH radicals, they would further react with additional H atoms to yield CH 3 SH again through Reaction (4). If chemical desorption occurs upon the formation of CH 3 SH, the CH 3 SH abundance will decline, as in the case of H 2 S in the H 2 S + H trials (Oba et al 2018).…”

Section: Introductionmentioning

confidence: 99%

Surface Reaction of Methyl Mercaptan (CH₃SH) with Hydrogen Atoms on Amorphous Solid Water

Nguyen

Oba

Sameera

et al. 2023

ApJ

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Methyl mercaptan (CH3SH) is one of the S-bearing organic compounds found in the interstellar medium (ISM). In this study, we investigated the surface reactions of solid CH3SH with H atoms on amorphous solid water using experimental and computational methods to examine their physicochemical behavior in the ISM. Consequently, the primary product was discovered to be CH4. As the computational studies show that the dominant reaction pathway is H + CH3SH → CH3 + H2S, the observed CH4 would result from H addition to CH3. As relatively minor routes, the H abstraction processes from the –CH3 and –SH functional groups of CH3SH, giving rise to CH2SH and CH3S radicals, are confirmed. Although these radicals may form CH3SH again by reactions with H atoms, the loss of CH3SH from the ice surface by chemical desorption would be minor.

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Section: Introductionmentioning

confidence: 99%

Surface Reaction of Methyl Mercaptan (CH₃SH) with Hydrogen Atoms on Amorphous Solid Water

Nguyen

Oba

Sameera

et al. 2023

ApJ

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Theoretical study on the atmospheric reaction of CH₃SH with O₂

Bian

Zhang

et al. 2018

Int J of Quantum Chemistry

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A detailed study on the reaction mechanism of CH3SH with O2 was carried out using quantum chemical methods. Eleven singlet pathways and four triplet pathways were found based on CCSD(T)//M06‐2x calculations. The nature of chemical bonding evolution was also studied using electron localization function and atoms in molecules analysis. Moreover, reaction rate constants were calculated between 200 and 800 K at the level of the transition state theory by Wigner tunneling correction. The results suggest that the main products should be CH2SO, H2O, CH3OH, SO, CH4, and SO2, respectively, basically coinciding with the experimental results. The corresponding feasible pathways are channels R7, R8, and R9, respectively, with an effective energy barrier of 56.21 kJ/mol. Obviously, given the low energy barrier similar to the main paths mentioned above, the products CH2SH and HO2 should assume a definite proportion in all possible products, although such species were not yet detected in experiment.

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From interstellar carbon monosulfide to methyl mercaptan: paths of least resistance

Lamberts

2018

A&A

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The 29 reactions linking carbon monosulfide (CS) to methyl mercaptan (CH 3 SH) via ten intermediate radicals and molecules have been characterized with relevance to surface chemistry in cold interstellar ices. More intermediate species than previously considered are found likely to be present in these ices, such as trans-and cis-HCSH. Both activation and reaction energies have been calculated, along with low-temperature (T > 45 K) rate constants for the radical-neutral reactions. For barrierless radical-radical reactions on the other hand, branching ratios have been determined. The combination of these two sets of information provides, for the first time, quantitative information on the full H + CS reaction network. Early on in this network, that is, early on in the lifetime of an interstellar cloud, HCS is the main radical, while later on this becomes first CH 2 SH and finally CH 3 S.

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Computational study on the mechanism and kinetics for reaction of CH 3 SH + H with water vapor

Cited by 4 publications

References 37 publications

Surface Reaction of Methyl Mercaptan (CH₃SH) with Hydrogen Atoms on Amorphous Solid Water

Surface Reaction of Methyl Mercaptan (CH₃SH) with Hydrogen Atoms on Amorphous Solid Water

Theoretical study on the atmospheric reaction of CH₃SH with O₂

From interstellar carbon monosulfide to methyl mercaptan: paths of least resistance

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Computational study on the mechanism and kinetics for reaction of CH 3 SH + H with water vapor

Cited by 4 publications

References 37 publications

Surface Reaction of Methyl Mercaptan (CH3SH) with Hydrogen Atoms on Amorphous Solid Water

Surface Reaction of Methyl Mercaptan (CH3SH) with Hydrogen Atoms on Amorphous Solid Water

Theoretical study on the atmospheric reaction of CH3SH with O2

From interstellar carbon monosulfide to methyl mercaptan: paths of least resistance

Contact Info

Product

Resources

About

Surface Reaction of Methyl Mercaptan (CH₃SH) with Hydrogen Atoms on Amorphous Solid Water

Surface Reaction of Methyl Mercaptan (CH₃SH) with Hydrogen Atoms on Amorphous Solid Water

Theoretical study on the atmospheric reaction of CH₃SH with O₂