物理化学学报 >> 2015, Vol. 31 >> Issue (9): 1699-1707.doi: 10.3866/PKU.WHXB201507202

理论与计算化学 上一篇    下一篇

锗硅烯与CH3OH加成反应机理及区域选择性

曾小兰,王岩*()   

  • 收稿日期:2015-05-07 发布日期:2015-09-06
  • 通讯作者: 王岩 E-mail:wangyanxytc@163.com
  • 基金资助:
    河南省基础与前沿技术研究计划(142300410194)

Mechanism and Regioselectivity of Addition Reactions of CH3OH to Germasilenes

Xiao-Lan. ZENG,Yan. WANG*()   

  • Received:2015-05-07 Published:2015-09-06
  • Contact: Yan. WANG E-mail:wangyanxytc@163.com
  • Supported by:
    Henan Provincial Fundamental and Frontier Technological Research Program, China(142300410194)

摘要:

采用密度泛函理论方法,在B3LYP/6-311++G(d, p)水平,研究了几种锗硅烯与CH3OH的加成反应的微观机理和势能剖面,分析了锗硅烯中Si=Ge双键的极性对加成反应区域选择性的影响.研究结果表明,锗硅烯可分别与CH3OH的单聚体或二聚体发生加成反应.所有加成反应均从初始亲核或亲电复合物的形成开始.母体锗硅烯H2Si=GeH2与CH3OH二聚体的加成反应比其与CH3OH单聚体的相应反应在动力学上更容易些,但在其它锗硅烯与CH3OH的反应中情况则相反.用Ph或SiMe3基团取代H2Si=GeH2中的H原子在动力学上使反应变得不利且SiMe3基团的影响更显著.加成反应的区域选择性与锗硅烯中Si=Ge双键的极性以及Si-O(Ge-H)和Ge-O (Si-H)键的相对强弱都有关.

关键词: 锗硅烯, 加成反应, 反应机理, 密度泛函理论, 区域选择性

Abstract:

Density functional theory (DFT) calculations of the reaction mechanisms and potential energy surfaces for the addition reactions of CH3OH to several germasilenes were performed at the B3LYP/6-311++G(d, p) level. The effect of the polarity of the Si=Ge double bond in germasilenes on the regioselectivity of the addition reactions was also investigated. The results indicate that germasilenes can react with a monomer or dimer of CH3OH. All reactions start with formation of nucleophilic or electrophilic complexes. The dimer of CH3OH adds to H2Si=GeH2 kinetically more easily than the monomer. However, the situation is generally the opposite for substituted germasilenes. There is a kinetic disadvantage of substituting phenyl (Ph) or SiMe3 groups for H atoms in H2Si=GeH2 in the addition reactions, and the effect of the SiMe3 group is more remarkable than that of the Ph substituent. Both the polarity of the Si=Ge double bond and the strength of the Si-O (Ge-H) and Ge-O (Si-H) bonds affect the regioselectivity of the addition reactions.

Key words: Germasilene, Addition reaction, Reaction mechanism, Density functional theory, Regioselectivity

MSC2000: 

  • O641