The study on gas phase dehydrogenation reactions of transition metal cation and ethylene

摘要: The reactivity of M+ (M = Os, Ir, Pt, Au) and ethylene is comparatively studied by the techniques of mass spectrometry in conjunction with theoretical calculations. Studies have shown that Os+, Ir+ and Pt+ can activate C–H bonds in ethylene to form OsC2H2+, IrC2H2+ and PtC2H2+ through dehydrogenation reaction, while Au+ cannot, which can be explained by the second HAT step. This is affected by the number of empty valence orbital of metals. In addition, for the activation capacity of Os+, Ir+, Pt+, the analysis of the free energy of rate-limiting step indicates the activation capacity is Os+ > Ir+ > Pt + . At the same time, the Os–C and C–C bonds of the first intermediate MC2H4+ are analysed, which shows that the stronger the interaction between M and the ligand C2H4 is, the shorter the C–C bond length in the ligand is, and the stronger the activation ability of the metal M may be.