Phenylgermane as a suitable precursor for laser flash photolysis measurements of germylene kinetics

R. Becerra, S.E. Boganov, M.P. Egorov, O.M. Nefedov and R. Walsh [Chem. Phys. Lett. 260 (1996) 433] reported the first direct kinetic measurements of germylene, GeH2, using two precursors, 3,4-dimethylgermacyclopentene and phenylgermane. They report that phenylgermane produces anomalously low reaction rate constants. We have re-examined this issue and measure rate constants using phenylgermane that agree with the values reported by Becerra et al. using the precursor 3,4-dimethylgermacyclopentene. The first direct rate constant measurement for GeH2 + phenylgermane is reported. All rate constants are found to be independent of the total pressure (measured to 50 Torr). Photolysis of phenylgermane at 248 and 193 nm yields the same values for the rate constants within the experimental uncertainty, suggesting that relaxation of vibrationally excited germylene is not altering the measured reaction rate constants. (C) 1999 Elsevier Science B.V. All rights reserved.