C_2H_2~＋＋H_2→C_2H_3~＋＋H反应振动选态速率常数的理论研究

Theoretical Study on Vibrational State-Selected Rate Constants of the Reaction C_2H_2￣+ +H_2→C_2H_3￣+ +H

用从头计算法辅以能一梯度法优化了反应Ｃ_２Ｈ＋Ｈ_２→Ｃ_２Ｈ＋Ｈ的过渡态，用福井谦一的理论求出反应途径，用反应途径哈密顿理论及正则变分过渡态理论计算沿反应途径的动力学性质和反应速率常数。在此基础上对涉及振动激发的选态反应速率常数进行计算，所得结果与现有的实验结果相符合。

The reaction path of the reaction C2H2+ + H2→C2H3+ +H has been traced by Fukui' s theory of intrinsic reaction coordinate by using an ab initio MO method with the gradient technique. Furthermore, the dynamical properties along the reaction path and CVT rate constants with correction of tunneling effect and effect of curvature have been investigated by reaction path Hamiltonian theory and variational transition state theory. On this basis,the enhancement of rate constant by vibrational excitation of C-C stretching mode has beencalculated. The calculated vibrational enhancement is of the same order of magnitude with the experimentally estimated value.