GALLIUM AND INDIUM COMPOUNDS CONTAINING 3 DIFFERENT SUBSTITUENTS - CRYSTAL AND MOLECULAR-STRUCTURE OF [(ME3CCH2)CLGAPPH2]3

Three new heavier group 13 element compounds containing three differen t substituents, (Me3CCH2)ClGaPPh2, (Me3CCH2)BrGaPPh2 and (Me3CCH2)ClIn PPh2, have been prepared and characterized. All compounds were charact erized by partial elemental analysis, cryoscopic molecular weight stud ies in benzene solution, and NMR and IR spectroscopic data. All three compounds exist as trimeric molecules in solution. NMR spectral data w ere consistent with the presence of multiple isomers of the trimers. T he compound [(Me3CCH2)ClGaPPh2]3 Crystallizes in the acentric space gr oup Pn2(1)a with a = 17.741(9)angstrom, b = 13.942(6) angstrom and c = 21.574(8) angstrom. Diffraction data were collected on an Enraf-Noniu s CAD-4 diffractometer. and the structure was refined to R = 4.6% and R(w) = 6.0% for those 2971 reflections with [F(o) greater-than-or-equa l-to 5sigma(F(o))]. The GaP six-membered ring has a typical chair conf ormation with the bulky neopentyl groups occupying the E,A,A, position s. Distances of interest include Ga-Cl = 2.209(4), 2.219(4) and 2.220( 4) angstrom and Ga-P(bridging) which range from 2.414(3) angstrom to 2 .433(4) angstrom.