CH_3SH+CN微观反应机理的理论研究  

Theoretical study on the reaction mechanism of CH_3SH+CN

作　　者：边江鱼[1,2] 

机构地区：[1]长春师范学院化学学院,吉林长春130032 [2]东北师范大学化学学院,吉林长春130024

出　　处：《分子科学学报》2009年第5期338-342,共5页Journal of Molecular Science

基　　金：东北师范大学自然科学青年基金资助项目(20070311)

摘　　要：采用BMC-CCSD//B3LYP/6-311G(d,p)方法对CH3SH+CN反应机理进行了详细的理论研究.反应中涉及的各稳定点的构型、振动频率和零点能在B3LYP/6-311G(d,p)水平下计算得到,计算结果表明,该反应存在两种反应机理,5条可能的反应通道.SN2机理由于能垒太高,与直接氢抽提机理相比可以忽略.该反应的最可行通道为CN中的C原子进攻SH中的H原子经由一个前期和一个后期分子络合物生成产物CH3S和HCN.计算得到的反应焓变与已有实验值非常吻合.A detailed theoretical survey on the potential energy surface for the CN＋ CH3SH reaction is carried out at the BMC-CCSD//B3LYP/6-311G（d,p） level.The geometries,vibrational frequencies,and energies of all stationary points involved in the reaction are calculated at the B3LYP/6-311G（d,p） level.The results suggest that there are two different mechanisms and five pathways in the title reaction.SN2 substitution reactions are less favourable than the direct H-abstraction reactions kinetically and thermodynamically.The dominant channel is the C atom in CN attacking H atom in SH group to form HCN and CH3S with a pre-reaction complex and a post-reaction complex involved.The calculated reaction enthalpies are in reasonable agreement with the available experimental data.

关 键 词：CH3SH CN 密度泛函理论 反应机理 

分 类 号：O641[理学—物理化学]