Decomposition of monochlorogallane, [H2GaCl]n, and adducts with amine and phosphine bases: Formation of cationic gallane derivatives

Thermal decomposition of monochlorogal lane, [H2GaCl](n), at ambient temperatures results in the formation of subvalent gallium species. To Ga[HGaCl3], previously reported, has now been added a second mixed-valence solid, Ga-4-[HGaCl3](2)[Ga2Cl6] (1), the crystal structure of which at 150 K shows a number of unusual features. Adducts of monochlorogallane, most readily prepared from the hydrochloride of the base and LiGaH4 in appropriate proportions, include not only the 1:1 molecular complex Me3P center dot GaH2Cl (2), but also 2:1 amine complexes which prove to be cationic gallane derivatives, [H2Ga(NH2R)(2)]+Cl-, where R = Bu-t (3a) or Bu-s (3b). All three of these complexes have been characterized crystallographically at 150 K.