H_2S和CH_3SH与硅锡烯加成反应的理论研究

采用密度泛函理论方法研究了H2S及CH3SH与硅锡烯的加成反应的微观机理和势能剖面.计算结果表明,所研究反应由多步机理组成且反应的初始步骤为H2S或CH3SH对硅锡烯的亲核进攻.反应过程中Si(Sn)-S键总是先于Sn(Si)-H键形成.形成Si-S键的反应在动力学上比形成Sn-S键的反应有利,且主要由能量因素决定.CH3SH作为亲核反应试剂比H2S更活泼.

Theoretical Study on the Addition Reactions of H_2S and CH_3SH with Silastannene

The mechanism and potential energy surface of the addition reactions of H2 S and CH3 SH to silastannene were studied by using density functional theory(DFT).The obtained results show that all reactions consist of a multi-step mechanism and the initial step of the reactions is a nucleophilic attack of H2 S or CH3 SH toward silastannene.The formation of Si-S or Sn-S bond is always prior to that of Sn-H or Si-H bond in all studied reactions.The reactions involving a forming Si-S bond are more favorable than those containing a forming Sn-S bond kinetically,which is determined by energy factor.CH3 SH as a nucleophile is more reactive toward silastannene than H2 S.