title: Theoretical studies on the reactions CH3SCH3 with OH, CF3, and CH3 radicals.
abstract: The multiple-channel reactions OH + CH(3)SCH(3) → products, CF(3) + CH(3)SCH(3) → products, and CH(3) + CH(3)SCH(3) → products are investigated by direct dynamics method. The optimized geometries, frequencies, and minimum energy path are all obtained at the MP2/6-31+G(d,p) level, and energetic information is further refined by the MC-QCISD (single-point) method. The rate constants for eight reaction channels are calculated by the improved canonical variational transition state theory with small-curvature tunneling contribution over the temperature range 200-3000 K. The total rate constants are in good agreement with the available experimental data and the three-parameter expressions k(1) = 4.73 × 10(-16)T(1.89) exp(-662.45/T), k(2) = 1.02 × 10(-32)T(6.04) exp(933.36/T), k(3) = 3.98 × 10(-35)T(6.60) exp(660.58/T) (in unit of cm(3) molecule(-1) s(-1)) over the temperature range of 200-3000 K are given. Our calculations indicate that hydrogen abstraction channels are the major channels and the others are minor channels over the whole temperature range.
authors.affiliation: Department of Chemistry, College of Chemical and Environmental Engineering, Harbin University of Science and Technology, Harbin 150080, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Gui-Ling
authors.initials: GL
authors.lastname: Zhang
authors.forename: Jing-Yao
authors.initials: JY
authors.lastname: Liu
authors.forename: Miao
authors.initials: M
authors.lastname: Sun
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Ze-Sheng
authors.initials: ZS
authors.lastname: Li
mesh_terms: D000465:Algorithms; D005466:Fluorocarbons / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D017665:Hydroxyl Radical / Q000737:chemistry*; D007700:Kinetics; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008956:Models, Chemical; D013463:Sulfuric Acid Esters / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D005466:Fluorocarbons; D005740:Gases; D013463:Sulfuric Acid Esters; C051224:methyl radical; D017665:Hydroxyl Radical; D006859:Hydrogen; C007482:dimethyl sulfate; D008697:Methane