Synthesis and Structures of Gallium Amido Imido Phenyl Clusters (PhGa)₄(NHⁱBu)₄(NⁱBu)₂ and (PhGa)₇(NHMe)₄(NMe)₅

The phenylgallium-containing clusters constructed with bridging imido and amido ligands, (PhGa)₄(NHⁱBu)₄(NⁱBu)₂ (1) (51% yield) and (PhGa)₇(NHMe)₄(NMe)₅ (2) (31% yield), were synthesized from the room-temperature reactions of bis(dimethylamido)phenylgallium, [PhGa(NMe₂)₂]₂, with isobutylamine and methylamine, respectively. The reaction of [PhGa(NMe₂)₂]₂ in refluxing isobutylamine (85 °C) afforded (Ph₂GaNHⁱBu)₂ as one of the products, while the reaction of [PhGa(NMe₂)₂]₂ with methylamine at 150 °C afforded compound 2 in only 9% yield. Compound 1 possessed an admantane-like Ga₄N₆ core, whereas compound 2 had a novel Ga₇N₉ core constructed with both chair- and boat-shaped Ga₃N₃ rings. The presence of several isomers of compounds 1 and 2 in solution is discussed along the structural similarities with other known gallium−nitrogen clusters and with gallium nitride.