PREPARATION, CHARACTERIZATION AND FACILE THERMOLYSIS OF [X2GAP(SIME3)2]2 (X = BR, I) AND (CL3GA2P)N - NEW PRECURSORS TO NANOCRYSTALLINE GALLIUM-PHOSPHIDE

[Br2GaP(SiMe3)2]2 and [I2GaP(SiMe3)2]2 have been prepared by the 1:1 mole ratio reaction of the corresponding gallium(III) halide with (Me3Si)3P. Direct introduction probe spectrometry indicates that the former product is dimeric in the gas phase; single-crystal X-ray analysis reveals that it is also dimeric in the solid state and it is isostructural with [Cl2GaP(SiMe3)2]2, but the crystals are not isomorphous. [Br2GaP(SiMe3)2]2 Crystallizes in the orthorhombic system, space group Pbca, with a = 13.803(2), b = 16.652(2), c = 13.636(2) angstrom, v = 3134(1) angstrom3, D(calc) = 1.725 g cm-3 for Z = 4; the mean Ga-P bond length the planar Ga-P-Ga-P core is 2.386 angstrom. Also described is the synthesis of (Cl3Ga2P)n via the 2:1 mole ratio reaction of GaCl3 and (Me3Si)3P. All of the title compounds undergo thermolysis at relatively low temperature to yield nanocrystalline GaP. Thermolysis has been studied by thermal gravimetric analysis, and the resultant air-stable powders have been characterized by X-ray diffraction and elemental analysis.