Room temperature observation of GeH2 and the first 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 wavenumber region 17109-17120 cm(-1), attributable to previously unobserved rotational transitions in the vibronic spectrum of GeH2. By time-resolved monitoring of GeH2, rate constants have been obtained for its reactions with O-2, C2H2, i-C4H8, 1,3-C4H6, C3H8 and Me(3)SiH. The measurements show that GeH2 is unreactive towards C-H bonds but inserts readily in Si-H bonds, as well as reacting rapidly (close to the collision rate), with pi-bonds. These results represent the first direct kinetic measurements on GeH2. Comparisons show that it is slightly less reactive than SiH2.