First gas-phase detection of dimethylgermylene and time-resolved study of some of its reactions

Using a laser flash photolysis/laser probe technique, applied to two different gaseous precursor molecules, we report absorption signals in the wavelength region 450–520 nm (maximum at 480 nm) which we attribute to GeMe2. Kinetic studies have been carried out, by time-resolved monitoring of GeMe2, of its reactions with O2, C2H4, CH2CHC(CH3)3, 1,3-C4H6, C3H8, Me3SiH and Me3GeH. The measurements show that GeMe2 is unreactive towards CH, SiH and GeH bonds but reacts fairly rapidly with π-bonded species. The reaction of GeMe2 with C2H4 has been found to be pressure-dependent, consistent with a third-body assisted association reaction forming 1,1-dimethylgermirane. These results represent the first rate constants measured in the gas-phase for any germylene. Differences with the solution reactivity of GeMe2 are discussed.