HNCO+OH->H2O+NCO的反应机理

采用从头算分子轨道法 (UHF/6 31G 水平 ,并用MP4加以相关能校正 )研究了HNCO OHH2 O NCO反应机理 .同时用Morokuma数值法获得了反应途径即内禀反应坐标 (IRC) .沿着IRC ,运用反应途径哈密顿理论 ,获得反应途径动态学信息 .在此基础上 ,根据过渡态理论和相应隧道效应校正 ,计算了在不同温度下的反应速率常数 ,得到了和实验相一致的结果 .计算结果表明 ,此反应是一步直接型的抽提H反应 .

Mechanism of Reaction HNCO+OH->H2O+NCO

The mechanism of the reaction HNCO +OH→H2 O +NCO has been studied by using ab initio MO method(at UMP4/6 31G** level) with energy gradient technique. The reaction path was traced with Fukui’s theory of intrinsic reaction coordinate (IRC). Along the IRC, some dynamics properties were investigated by applying reaction path Hamiltonian theory. On this basis, the rate constants of the reaction at different temperatures were calculated by transition state theory with correction of quantum effect. The theoretically calculated rate constants are in good agreement with experimental results. This shows that the reaction is a direct reaction of hydrogen abstraction with only one step.