H_3PO、H_2FPO分子消除反应的理论研究

A THEORETICAL STUDY ON THE SUBDUCTIONREACTION OF H_3 PO AND H_2FPO

本文用内禀反应坐标法(IRC)讨论了 H_3PO(RI)脱 H_2和 H_2FPO(R_2)脱 HF的1,1消除反应的机理.通过量子化学从头算和反应路径解析,得出了过渡态结构、反应势能曲线、活化能、反应热及沿反应坐标反应系的一些物理量的变化.对过渡态做了振动分析,给出了沿反应坐标分子间弹性碰撞阶段等信息.计算了沿反应的频率因子、活化熵和速率常数.得到了(Ⅱ)的消除反应较(Ⅰ)容易进行的结论.

In this paper,the mechanisms of subduction reaction of H_3PO dehydrogenation and H_2FPO dehydrogenfluoride into HPO are studied by means of intrinsic reaction coordinate(IRC) method.The reaction ergodographies of H_3PO and H_2FPO are analyazed by ab initio MO method at 4-31GF basis set.The structures of transition states,potential energy curves,activation ener- gies,heats of reaction and the change of smoe physical quantities of each reaction path have been determined and the vibrational analyses for the transition states have also been made.The theore- tioal results of both reaction pathes are studied by comparison and valuable information about the Collision angles and the boundary of elastic collision is obtaind.The frequenoy factor,activation entropies at T=500K and the rate constants of each reaction are caloulated.From those results, we come to the conolusion that the reaotion(Ⅱ)takes precedence of reaction(Ⅰ).