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4321849 
Journal Article 
Atmospheric nucleation precursors catalyzed isomerization of CH2SH to CH3S: mechanisms and topological analysis 
Cao, Jia; Wang, ZhiX; Gao, LouJun; Fu, F 
2015 
1 
Structural Chemistry
ISSN: 1040-0400
EISSN: 1572-9001 
26 
1 
261-268 
WOS:000347954800026 
The isomerization of CH2SH to CH3S in the absence and presence of atmospheric nucleation precursors (H2O, HCOOH, and H2SO4) has been investigated at the G3XMP2//B3LYP/6-311+G(3df,2p) level. It is shown that the barrier heights for the isomerization are 28.74, 6.45, 12.96, and 19.23 kcal mol(-1), when the isomerization is performed in gas phase and with sulfuric acid, water, and formic acid as a precursor, respectively. The rate constants of the isomerization are calculated using the transition state theory with the Wigner tunneling correction over the temperature range of 298-800 K. The rate constant of sulfuric acid-catalyzed isomerization is 1.46 x 10(3) times at 298 K larger than that in gas phase. Sulfuric acid-catalyzed isomerization is expected to be favorable under atmospheric condition. Moreover, topology analysis has been carried out to characterize the nature of interactions in the isomerization. Enthalpies of formation (Delta H-f(298K)degrees), entropies (S-298K degrees), and heat capacities (Cp) of all the stabilized species have been calculated using CBS-QB3 method. These results can be used for atmosphere sulfur cycle modeling application. 
CH2SH; CH3S; Atmospheric nucleation precursors; Isomerization mechanism; Topological analysis