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

Abstract

Reactions of the tris(2-pyridyl)lead(II) compound [LiPb(2-py6OtBu)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-py6OtBu)2]2 (2), [LiGaR2(2-py6OtBu)2(THF)] (R = iPr (3), tBu (4)), [LiGatBu2(2-py6OtBu)2]2 (4'), and [LiGaMe(2-py6OtBu)3] (6), as well as corresponding indium complexes of general composition [LiInR(2-py6OtBu)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 [tBu3Ga{Pb(2-py6OtBu)3Li}] (5). In addition, the redox transmetalation route was used for the synthesis of [LiInI(2-py6OtBu)3(THF)] (9). The structures of all compounds have been verified by single-crystal X-ray diffraction analysis, NMR spectroscopy, and mass spectrometry.