Formation and Structural Characterization of the Mixed-Metal Pnicogen-Bridged Four-Membered Ring Compounds (Et2O)2Li[μ-E(SiMe3)2]2GaH2 (E = P, As)

Two compounds with novel connectivities, (Et2O)2Li[μ-E(SiMe3)2]2GaH2 (E = P (1), As (2)), formally lithium pnictidogallates, were synthesized in the reactions between LiGaH4 and E(SiMe3)3 in diethyl ether via trimethylsilane elimination. No reaction took place for E = N under comparable conditions. Structural characterizations showed 1 and 2 to be isomorphous in the solid state and feature the planar four-membered rings of the {Li[μ-E]2Ga} core.