Bis(2-pyridyl) and Tris(2-pyridyl) Compounds of Gallium and Indium via a Redox-Transmetalation Route

Reactions of the tris(2-pyridyl)lead(II) compound [LiPb(2-py^6O)₃] (1) with trialkyl compounds of the group 13 elements gallium and indium resulted in the bis(2-pyridyl) and tris(2-pyridyl) gallate complexes [LiGaEt₂(2-py^6O)₂]₂ (2), [LiGaR₂(2-py^6O)₂(THF)] (R = Pr (3), Bu (4)), [LiGaBu₂(2-py^6O)₂]₂ (4'), and [LiGaMe(2-py^6O)₃] (6), as well as corresponding indium complexes of general composition [LiInR(2-py^6O)₃] (R = Me (7), Et (8)). The formation of these compounds can be assumed as a rapid degradation of initially formed Pb-M adducts (M = Ga or In) as found for [Bu₃Ga{Pb(2-py^6O)₃Li}] (5). In addition, the redox transmetalation route was used for the synthesis of [LiInI(2-py^6O)₃(THF)] (9). The structures of all compounds have been verified by single-crystal X-ray diffraction analysis, NMR spectroscopy, and mass spectrometry.