CH_3SS与XO(X=F,Cl,Br)反应过程的电子密度拓扑研究

Topological Analysis of Electronic Density on the Reactions of CH_3SS with XO(X=F,Cl and Br)

利用MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p)对CH3SS与XO(X=F,Cl,Br)的反应机理进行了研究.着重从电子密度拓扑分析角度讨论了化学键的生成和断裂.计算结果表明单线态反应为主要反应通道,且由于该通道的反应能垒低、放热明显,说明CH3SS与XO在大气中比较容易进行.电子密度拓扑分析表明,在单线态抽氢反应通道中存在着四元环状过渡结构,随着反应进行,此四元环状过渡结构通过一个T-型结构变为三元环状过渡结构,最后环状结构消失得到产物.

The reaction mechanism of CH3SS with XO （X=F, CI, Br） has been studied at MP2/6-311 ＋ ＋ G（d,p）//B3LYP/6-31 1 ＋ ＋G（d,p） level. The breakage and formation of the chemical bonds in the main reaction channel have been discussed by the topological analysis method of electronic density. The calculated results show that because of the low energy barrier and high exothermicity, the reaction of CH3SS with XO could occur easily in the atmosphere. Furthermore, the topological analysis shows that a four-membered ring structure exists in the hydrogen abstract channel, it turns to a three-membered ring structure by a T-shaped structure, then the ring structure disappears and the products are gained.