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化学学报
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化学学报 ›› 2005, Vol. 63 ›› Issue (4): 295-300. 上一篇    下一篇

研究论文

Cl原子与CH2SH自由基反应机理及电子密度拓扑研究

孙翠红1,2，曾艳丽1,3，孟令鹏1，郑世钧*,1   

  1. (1河北师范大学计算量子化学研究所 石家庄 050091)
    (2石家庄学院化学系 石家庄 050000)
    (3中国科学院研究生院化学系 北京 100039)
  • 投稿日期:2004-02-09 修回日期:2004-10-29 发布日期:2010-12-10
  • 通讯作者: 郑世钧

Reaction Mechanisms and Topological Studies of ElectronDensity on the Reaction of CH2SH Radical and Cl Atom

SUN Cui-Hong1,ZENG Yan-Li1,2,MENG Ling-Peng1,ZHENG Shi-Jun*,1   

  1. (1 Institute of Quantum Chemistry, Hebei Normal University, Shijiazhuang 050091)
    (2 Department of Chemistry, College of Shijiazhuang, Shijiazhuang 050000)
    (3 Department of Chemistry, Graduate School, Chinese Academy of Sciences, Beijing 100039)
  • Received:2004-02-09 Revised:2004-10-29 Published:2010-12-10
  • Contact: ZHENG Shi-Jun

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采用MP2(Full)/6-311G(d,p)和B3LYP/6-311G(d,p)找到了反应Cl＋CH2SH→HCl＋CH2S的两个可能的反应通道, 得到了各反应通道的反应物、中间体、过渡态和产物的优化构型、谐振频率. 对反应进程中若干关键点进行了电子密度拓扑分析, 讨论了反应进程中键的断裂、生成和化学键的变化规律, 找到了该反应的结构过渡区(结构过渡态)和能量过渡态, 发现了反应热与结构过渡区之间的关系.

关键词: 自由基反应, 能量过渡态, 结构过渡态, 结构过渡区, 电子密度拓扑分析

Two possible reaction channels for the reaction of CH2SH＋Cl have been studied at the MP2(Full)/6-311G(d,p) and B3LYP/6-311G(d,p) levels. Geometries of the reactants, intermediates, transition states and products were optimized and IRC calculations were carried out. The computed results show that the reaction proceeds through the addition of a Cl atom to CH2SH by either Cl—C or Cl—S combination to form initial intermediates. The cleavage and formation of the chemical bonds in the reaction pathways have been discussed by the topological analysis of electronic density. The “energy transition state” and the “structure transition state” in both channels of the studied reaction have been found. The calculated results suggest the relationship between the reaction enthalpy and the “structure transition region”.

Key words: radical reaction, energy transition state, structure transition state, structure transition region, topological analysis of electronic density