Please use this identifier to cite or link to this item: https://doi.org/10.1016/S0166-1280(98)00494-1
Title: A Gaussian-2 ab initio study of [C2H5S]+ ions: II. Fragmentation pathways of CH3SCH+/2 and CH2CHSH+/2 revisited
Authors: Chiu, S.-W.
Cheung, Y.-S.
Ma, N.L. 
Li, W.-K.
Ng, C.Y.
Keywords: [C2H5S]+ ions
Gaussian-2 theory
Ion- molecule complexes
Ion-radical complexes
Unimolecular dissociations
Issue Date: 9-Aug-1999
Source: Chiu, S.-W.,Cheung, Y.-S.,Ma, N.L.,Li, W.-K.,Ng, C.Y. (1999-08-09). A Gaussian-2 ab initio study of [C2H5S]+ ions: II. Fragmentation pathways of CH3SCH+/2 and CH2CHSH+/2 revisited. Journal of Molecular Structure: THEOCHEM 468 (1-2) : 21-37. ScholarBank@NUS Repository. https://doi.org/10.1016/S0166-1280(98)00494-1
Abstract: Gaussian-2 ab initio method was performed to examine the five modes of unimolecular dissociation of CH3SCH+/2 (1+) and CH2CHSH2/+ (5+): 1+ → CH3 + H2CS+ (1); 1+ → CH3/+ + H2CS (2); 1+ → CH4 + HCS+ (3); 5+ → H2S + [C2H3]+(4); and 5+ → H3S+ + C2H2 (5). Both reactions 1 and 2, with endothermicities 359 and 395 kJ mol-1 respectively, proceed without a reverse barrier. Loss of CH4 from 1+ (reaction 3) proceeds via a transition state resembling an ion-radical complex CH3 H2CS+. The elimination reaction has an energy barrier of 332 kJ mol-1 Loss of H2S from 5+ (reaction 4) initially proceeds through either cleavage of the C-S bond or formation of the ion-molecule complex H2S/[C2H3]+ (8+/9+), followed by dissociation of the complex. The endothermicity of reaction 4 is calculated to be 245-261 kJ mol-1. Reaction 5, the lowest energy process among the dissociation pathways studied in this work, proceeds via intermediates 9+ and H3S+/C2H2 (10+). Its rate-determining step 5+ → 9+ has an energy barrier of 220 kJ mol-1.
Source Title: Journal of Molecular Structure: THEOCHEM
URI: http://scholarbank.nus.edu.sg/handle/10635/92941
ISSN: 01661280
DOI: 10.1016/S0166-1280(98)00494-1
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

SCOPUSTM   
Citations

9
checked on Feb 20, 2018

Page view(s)

36
checked on Feb 16, 2018

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.