LIU Yan1,2*, LU Yanxia1, WANG Weina1
(1 School of Chemistry and Chemical Engineering, Key Laboratory for Macromolecular Science of Shaanxi Province, Shaanxi Normal University, Xi′an 710119, Shaanxi, China; 2 College of Chemistry and Materials, Shaanxi Engineering Research Center of Coal Conversion Alcohol, Weinan Normal University, Weinan 714099, Shaanxi, China)
Abstract:
The reaction mechanisms of CH3SS and HO2 radicals were studied by using the density functional method MPW1PW91/6-311G(d,p). Optimized geometries of reactants, intermesiate, transition states and products were verified by the analysis of vibration frequency and intrinsic reaction coordinate (IRC). High accurate energy information was provided by the QCISD(T)/6-311G(d,p)// MPW1PW91/6-311G(d,p)+ZPE method. It is found that CH3SS could react with HO2 radical and produce 12 decomposed products by through 9 reaction paths. The Path R→3IM1→TS1a→P1(CH3SSH+3O2) would be the favorable reaction due to the lowest energy barrier of 25.15 kJ/mol. The fitted Arrhenius expression for the calculated CVT/SCT rate constant for the rate controlling step in the favorable pathway is kCVT/SCT=1.03×1010T0.51exp(-402.7/T)s-1 in the temperature range of 200~2 000 K.
KeyWords:
CH3SS; HO2 radical; density functional theory; reaction mechanism
