Reactions of the Digallium Compound R2Ga-GaR2 [R = CH(SiMe3)(2)] with Water and Carboxylic Acids - Synthesis of mu-Hydroxo-mu-carboxylatodigallium Compounds with Retention of the Ga-Ga Bonds

Uhl W, Bock HR, Hepp A, Rogel F, Voss M

Abstract

Treatment of the digallium compound R2Ga-GaR2 [1, R = CH(SiMe3)2] with a broad variety of functionalized carboxylic acids in the presence of water yielded mu-hydroxo-mu-carboxylatodigallium compounds (2-10) containing intact Ga-Ga bonds in high to moderate yields. The compounds form dimeric formula units in which the unsupported Ga-Ga bonds are bridged by two hydroxo and two carboxylato ligands. Each gallium atom is terminally coordinated by a bulky alkyl group. NMR spectroscopy revealed mixtures of two isomeric compounds in solution in all cases. The second component may show a different bridging mode with each Ga-Ga bond bridged by a bidentate carboxylato ligand to form Ga2O2C five-membered heterocycles.