锗硅烯与H_2O加成反应的计算研究

采用密度泛函理论方法研究了两种锗硅烯(H2Ge=Si H2及Ph2Ge=Si Ph2)与H2O的加成反应的微观机理和势能剖面,分析了加成反应中区域选择性的起源.计算结果表明,H2O的单聚体、二聚体及三聚体均可作为亲核试剂与锗硅烯发生加成反应.形成Si—O键和Ge—O键的反应均为复杂反应,且Si(Ge)—O键比Ge(Si)—H键优先形成.加成反应的区域选择性由动力学因素决定.H2O作为亲核试剂的反应活性低于CH3OH.

Computational Study on the Addition Reactions of Germasilenes with H_2O

The mechanism and potential energy surface for the addition reactions of two germasilenes( H_2Ge = SiH_2 and Ph_2Ge = SiPh_2) with H_2O were investigated by using density functional theory( DFT),and the origin of the regioselectivity for addition reactions was analyzed. The results indicated that the monomer,dimer or trimer of H_2O may react with germasilenes as nucleophilic reagent. Both the reactions involving a forming Si—O or Ge—O bond are complicated reactions,and the formation of Si( Ge) —O bond precedes that of Ge( Si) —H bond. The regioselectivity of addition reactions is decided by kinetic factor. Behaving as a nucleophilic reagent,H2 O is less reactive toward germasilene than CH_3OH.