H与CF_3O_2自由基反应的理论研究

THEORETICAL STUDIES ON REACTION OF H WITH CF_3O_2 RADICAL

用从头算 (abinitio)方法和密度泛函理论 (DFT)对H与CF3O2 自由基的反应进行了研究 .在HF 6- 31G 和B3LYP 6 - 31G 基组水平上 ,对该反应过程中可能出现的中间体和过渡态的构型及能量进行了优化 ,并分析了反应过程中生成的产物 .对各过渡态 ,利用内禀反应坐标IRC来进行验证 .在B3LYP 6 - 31G 构型优化的基础上 ,用B3LYP 6 - 31 1G 和B3LYP 6 - 31 1 +G 计算了反应过程中各物种的总能量和相对能量 ,根据相对能量绘制的势能剖面图直观地反映了H +CF3O2 的反应机理 .由势能面得出 ,反应生成CF3O和OH的历程最容易发生 。

The ab initio MO method and density functional theory(DFT) have been used to study the CF-3O-2+H reaction. The configurations and energies of the possible intermediates and transition states for the reaction have been optimized at the HF/6-31G~* and B3LYP/6-31G~* levels, together with the analysis of the products. For the transition states, the calculation of internal reaction coordinate (IRC) has been used to validate them. On the basis of the optimized configurations at the B3LYP/6-31G~*level, the total energies and the relative energies for various species have been calculated using B3LYP/6-311G^(**)and B3LYP/6-311+G^(**), and the profile of potential energy surface by the relative energies reflects the reaction mechanism intuitively. According to the potential energy surface, the production of CF-3O and OH is the major reaction course, and this result agrees with the experiment.