Gallium-Gallium Bonds Bridged by Functionalized Carboxylato Ligands

Uhl W, Bock HR, Kosters J, Voss M

Zusammenfassung

Treatment of the tetraalkyldigallium compound R2Ga-GaR2 [R = CH(SiMe3)(2)] (1) with a large number of different functionalized carboxylic acids afforded dicarboxylatodigallium compounds R2Ga2(mu-O2C-R)(2), in which two carboxylato ligands bridge the Ga-Ga bonds. The chelating ligands have additional nitrogen, oxygen or phosphorus donor atoms and may be suitable to act as Lewis-bases to yield supramolecular aggregates in future investigations. Four compounds have been characterized by crystal structure determinations. One gave unprecedented dimeric formula units in the solid state by Ga-N interactions. The similar reaction with isonicotinic acid resulted in the cleavage of the Ga-Ga bond. A tetragallium compound was formed in which four isolated metal atoms were bridged by four organic ligands to give a square molecular core.