Temperature dependence of germylene reactions with acetylene, trimethylsilane, and phenylgermane

Gas-phase reaction rate constants have been determined over the temperature range 295–436 K for the reactions of germylene, GeH2, with acetylene (GeH2 addition across a triple bond), trimethylsilane (GeH2 insertion into a Si–H bond), and phenylgermane. The room-temperature rate constant for germylene reacting with benzene has been measured and is found to be a factor of ∼300 smaller than that for phenylgermane, indicating that the latter reacts by GeH2 insertion into the Ge–H bonds. A negative temperature dependence is observed in all cases. The activation energies, obtained from weighted linear fits to the data over the experimental temperature range, are −3.5±0.3, −11.0±0.4, and −3.6±0.3 kJ mol−1 for acetylene, trimethylsilane, and phenylgermane, respectively, while the respective frequency factors, log(A/cm3 molecule−1 s−1), are −10.5±0.1, −11.8±0.1, −10.1±0.1.