CONTRIBUTIONS TO THE COORDINATION AND STRUCTURAL CHEMISTRY OF GALLIUM(III) AND INDIUM(III) HALIDES - COMPLEXES WITH BIDENTATE AND TRIDENTATE TERTIARY PHOSPHANES

The reactions of gallium and indium trihalides with 1,2-bis(diphenylph osphanyl)benzene (DP) and bis[(2-diphenylphosphanyl)phenyl]phenylphosp hane (TP) lead to a variety of molecular and ionic complexes. Treatmen t of InCl3 with DP results in [(DP)(2)InCl2](+)[InCl4](-) (1). With In Br3 or InI3 molecular 1:1 complexes (DP)InX3 (2: X = Br, 3: X = I) and ionic 1:2 complexes [(DP)InX2]+[InX4](-) (4: X = Br, 5: X = I) are ob tained. With GaBr3 and GaI3 only the ionic complexes [(DP)GaX2](+)[GaX 4](-) (6: X = Br, 7: X = I) are generated. According to single-crystal X-ray analyses the environment of the metal center is octahedral in t he cation of 1, square pyramidal in 3, and tetrahedral in the cations of 5 and 7. The reactions of TP with GaI3 or InI3 afford ionic complex es [(TP)MI2](+)[MI4](-) (8: M = Ga, 9: M = In). As shown by P-31-NMR s tudies and X-ray analyses, TP acts as a bidentate Ligand in both compl exes. The central phosphorus atom is not engaged in coordinative bondi ng. The P-31 resonances of all compounds appear at higher field as com pared to the free ligand. This phenomenon calls for further investigat ions and a detailed theoretical treatment.