Neutral, Cationic and Hydride-substituted Siloxygermylenes.

The introduction of the labile trimethylsiloxy group to GeII centers in the presence of an N-heterocyclic carbene donor is reported. The new complex IPr⋅GeCl(OSiMe3 ) (IPr=[(HCNDipp)2 C:]; Dipp=2,6-iPr2 C6 H3 ) was readily converted into the structurally unique GeII siloxy(hydrido)germylene IPr⋅GeH(OSiMe3 )⋅BH3 by treatment with lithium borohydride. Additionally, the reactive siloxygermylene cation [IPr⋅Ge(OSiMe3 )]+ was synthesized and clean oxidative addition of CH2 Cl2 was demonstrated. The two-coordinate [IPr⋅Ge(OSiMe3 )]+ cation also promoted the catalytic hydroborylation of sterically hindered ketones under mild conditions, with enhanced reactivity stemming from an open coordination site at Ge.