College of Chemical and Environmental Engineering, Harbin University of Science and Technology, Harbin 150080, People's Republic of China.
J Mol Model. 2013 Apr;19(4):1515-25. doi: 10.1007/s00894-012-1704-9. Epub 2012 Dec 21.
Theoretical investigations were carried out on the multi-channel reactions CF3 + SiHF3, CF3 + SiHCl3, CH3 + SiHF3, and CH3 + SiHCl3. Electronic structures were calculated at the MP2/6-311+G(d,p) level, and energetic information further refined by the MC-QCISD (single-point) method. The rate constants for major reaction channels were calculated by the canonical variational transition state theory with small-curvature tunneling correction over the temperature range of 200-1,500 K. The theoretical rate constants were in good agreement with the available experimental data and were fitted to the three parameter expression: k 1a(T) = 2.93 × 10(-26) T (4.25) exp (-318.68/T), and k 2a(T) = 3.67 × 10(-22) T (2.72) exp (-1,414.22/T), k 3a (T) = 7.00 × 10(-24) T (3.27) exp (-384.04/T), k 4a(T) = 6.35 × 10(-22) T (2.59) exp (-603.18/T) (in unit of cm(3)molecule(-1)s(-1)) are given. Our calculations indicate that hydrogen abstraction channel is the major channel due to the smaller barrier height among four channels considered.
对 CF3 + SiHF3、CF3 + SiHCl3、CH3 + SiHF3 和 CH3 + SiHCl3 的多通道反应进行了理论研究。在 MP2/6-311+G(d,p)水平上计算了电子结构，并通过 MC-QCISD（单点）方法进一步细化了能量信息。在 200-1500 K 的温度范围内，通过正则变分过渡态理论和小曲率隧道校正计算了主要反应通道的速率常数。理论速率常数与可用的实验数据吻合良好，并拟合为三参数表达式：k1a(T) = 2.93 × 10(-26) T (4.25) exp (-318.68/T)，k2a(T) = 3.67 × 10(-22) T (2.72) exp (-1414.22/T)，k3a(T) = 7.00 × 10(-24) T (3.27) exp (-384.04/T)，k4a(T) = 6.35 × 10(-22) T (2.59) exp (-603.18/T)（单位为 cm(3)molecule(-1)s(-1)）。我们的计算表明，由于四个通道中考虑的氢提取通道的势垒高度较小，因此氢提取通道是主要通道。
