HNCS与Cl原子的反应机理及电子密度拓扑分析

在QCISD(T)/6-311++G(d,p)和B3LYP/6-311++G(d,p)级别上研究了HNCS与Cl原子的反应机理. 并应用经典过渡态理论和正则变分过渡态理论结合小曲率隧道效应, 计算了200-2500 K温度范围内各反应通道的速率常数. 结果表明, HNCS与Cl原子反应存在3个反应通道. 当温度低于294 K时, 生成HCl+NCS的夺氢反应(a)是优势通道, 温度高于294 K时, 生成HNC(Cl)S的加成反应(c)为主反应通道, Cl进攻N的反应通道(b)因能垒较高而难以进行.

Reaction Mechanism and Topological Analysis of Electronic Density for the Reaction of HNCS with Cl

The reaction mechanism of HNCS with Cl was investigated at the QCISD(T)/6-311++G(d,p) and B3LYP/6-311++G(d,p) levels of theory. Reaction rate constants were calculated over a temperature range of 200-2500 K using classical transition state theory and canonical variational transition state theory combined with a small-curvature tunneling correction. Results show that there are three reaction channels for the HNCS+Cl reaction. At temperatures lower than 294 K, hydrogen abstraction reaction (a) is the major channel and HCl+NCS are the main products, while addition reaction (c) is the major reaction process and HNC(Cl)S is the dominant product at temperatures higher than 294 K. Reaction channel (b), where Cl atom attacks N atom, is a difficult process because of the higher energy barrier.