Central Institute of Aviation Motors, 2, Aviamotornaya St., 111116 Moscow, Russia.
Phys Chem Chem Phys. 2011 Sep 28;13(36):16424-36. doi: 10.1039/c1cp21269a. Epub 2011 Aug 15.
A comparative analysis of predictive ability of three approaches to estimate the rate constants of reactions of H(2), H, H(2)O and CH(4) with electronically excited O(2)(a(1)Δ(g)) and O(2)(b(1)Σ(g)(+)) molecules is conducted. The first approach is based on a detailed ab initio study of potential energy surfaces. The second one is known as the "bond energy-bond order" method, and the third approach is a modification of the updated method of vibronic terms that makes it possible to evaluate the activation energy of reactions involving electronically excited species. The comparison showed that the estimates of the energy barrier by the updated method of vibronic terms for some reactions can be in good agreement with ab initio calculations and available experimental data. It was revealed that reactions of O(2)(b(1)Σ(g)(+)) molecules with H(2), H(2)O and CH(4) molecules and with the H atom result in the formation of electronically excited species. The reactivity of O(2)(b(1)Σ(g)(+)) molecules is smaller than that of O(2)(a(1)Δ(g)) ones, but much higher as compared to the reactivity of ground state O(2) molecules. For each reaction under study involving oxygen molecules in the excited electronic states O(2)(a(1)Δ(g)) and O(2)(b(1)Σ(g)(+)) the recommended temperature-dependent rate constants are presented.
对三种方法预测 H(2)、H、H(2)O 和 CH(4)与电子激发态 O(2)(a(1)Δ(g))和 O(2)(b(1)Σ(g)(+))分子反应速率常数的能力进行了比较分析。第一种方法基于对势能面的详细从头算研究。第二种方法称为“键能-键序”方法，第三种方法是对涉及电子激发态的反应的振动态项的更新方法的修改，使其能够评估反应的活化能。比较表明，对于一些反应，振动态项的更新方法估计的能垒可以与从头算计算和可用的实验数据很好地吻合。结果表明，O(2)(b(1)Σ(g)(+))分子与 H(2)、H(2)O 和 CH(4)分子以及 H 原子的反应导致电子激发态物种的形成。O(2)(b(1)Σ(g)(+))分子的反应性小于 O(2)(a(1)Δ(g))分子，但比基态 O(2)分子的反应性高得多。对于研究中涉及到的每个反应，都给出了推荐的温度相关速率常数。
