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 GeMe(2). Kinetic studies have been carried out, by time-resolved monitoring of GeMe(2), of its reactions with O-2, C2H4, CH2 = CHC(CH3)(3), 1,3-C4H6, C3H8, Me(3)SiH and Me(3)GeH. The measurements show that GeMe(2) is unreactive towards C-H, Si-H and Ge-H bonds but reacts fairly rapidly with pi-bonded species. The reaction of GeMe(2) 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 GeMe(2) are discussed.