Department of Chemistry, College of Chemical and Environmental Engineering, Harbin University of Science and Technology, Harbin 150080, People's Republic of China.
J Comput Chem. 2010 Nov 30;31(15):2794-803. doi: 10.1002/jcc.21572.
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.
OH + CH(3)SCH(3) → 产物、CF(3) + CH(3)SCH(3) → 产物和 CH(3) + CH(3)SCH(3) → 产物的多通道反应通过直接动力学方法进行研究。在 MP2/6-31+G(d,p)水平上获得了优化的几何形状、频率和最小能量路径，并且通过 MC-QCISD（单点）方法进一步细化了能量信息。通过改进的正则变分过渡态理论，结合小曲率隧道贡献，在 200-3000 K 的温度范围内计算了八个反应通道的速率常数。总速率常数与可用的实验数据和三参数表达式 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)（单位为 cm(3) molecule(-1) s(-1)) 在 200-3000 K 的温度范围内给出。我们的计算表明，在整个温度范围内，氢提取通道是主要通道，其他通道是次要通道。
