CH3SCH3在Fe＋作用下的脱烷基化反应机理的理论研究  

Theoretical Study on the Mechanism of Fe^+-mediated Demethanation of CH_3SCH_3 under Atmospheric Conditions

作　　者：张士国[1,2] 卞贺[2] 李大枝[1] 于宏超[2] 夏道宏[2] 

机构地区：[1]滨州学院化学与化工系,滨州市材料化学重点实验室,滨州256603 [2]中国石油大学华东化学化工学院,东营257061

出　　处：《分子催化》2010年第5期443-449,共7页Journal of Molecular Catalysis(China)

基　　金：山东省自然科学基金(ZR2009BL002)

摘　　要：采用密度泛函理论的B3LYP方法,在6-311++G(d,p)和DGDZVP基组水平上研究了CH3SCH3在Fe+作用下的脱烷基化的四重态和六重态微观反应机理,全参数优化了反应势能面上各驻点的几何构型,振动分析和内禀反应坐标(IRC)分析结果证实了中间体和过渡态的真实性.找到了三条可能的反应通道,对结果的分析表明:对于六重态的反应体系,二甲硫醚的脱甲烷化反应主要经历了四个基本步骤,即先驱复合物、C—S活化、(-H转移和非反应性的分裂.对于四重态的Fe+/CH3SCH3反应体系,含有C—S和C—H插入反应的两个路径都可以导致脱甲烷反应的发生,其中C—S插入反应路径的能垒较低,是主要反应通道.The demethanation reactions of dimethyl sulfide by Fe＋ on both quartet and sextet potential energy surfaces have been investigated using density functional theory（B3LYP） in conjunction with the DGDZVP and 6-311＋G（d,p） basis sets.Geometries of the stationary points were completely optimized.The transition states were validated by the vibrational analysis and the internal reaction coordinate（IRC） calculations.The vibration analysis and the IRC analysis testified the authenticity of intermediates and transition states.The calculation results indicate that,along the energetically preferable sextet pathway,the demethanation reaction can occur through four elementary steps,that is,encounter complexation,C-S activation,β-H shift,and nonreactive dissociation.Whereas along the quartet PES,both the C-S and methyl C-H activation could result in the demethanation reaction,of which,the reaction involving C-S activation is calculated to be the main pathway with relative lower energy barriers and intermediates.

关 键 词：二甲基硫醚 脱烷基化 反应机理 密度泛函 

分 类 号：O641.12[理学—物理化学]