THERMALLY-INDUCED TRANSFORMATIONS OF GALLIUM AND INDIUM ALKYL PHOSPHIDO COMPLEXES - DEALKYLSILYLATION ROUTES TO MP (M=GA, IN)

The dehalosilylation reaction of (Bu2GaCl)-Bu-n with 1 equiv of P(SiMe 3)(3) provided [(Bu2GaP)-Bu-n(SiMe3)(2)](2) (1) in good yield. A simil ar reaction between (BuGaCl2)-Bu-n and P(SiMe3)(3) gave [Bu-n(Cl)GaP(S iMe3)(2)](2) (2). Compound 1 was characterized by X-ray crystallograph y and possesses an approximately square planar Ga2P2 molecular core. B oth the P and the Ga centers are in distorted tetrahedral environments . Thermolysis of 1, at 400 degrees C, produced GaP and BuSiMe3 and no other crystalline products, as confirmed by thermogravimetric and spec troscopic analysis. The indium analogue of 1, [(Bu-n)(2)InP(SiMe3)(2)] (2) (3), was prepared from the reaction of (Bu-n)(2)InCl with P(SiMe3) (3). The thermolysis of 3 at 400 degrees C under nitrogen produced but ene, butane, and butyltrimethylsilane as organic products and a dark g rey solid. Powder X-ray diffraction of this solid revealed it to consi st of InP add metallic indium. Combination of In(Bu-n)(3) with P(SiMe3 )(3) produced the monomeric adduct (Bu-n)(3)In . P(SiMe3)(3) (4). The thermal reactivity of complex 4 was investigated at various temperatur es. At 130 degrees C in a sealed tube, the products of thermolysis are [(Bu-n)(2)InP(SiMe3)(2)](2) (3) and In-0. While complex 1 is a potent ial precursor to GaP via a dealkylsilylation mechanism, the indium ana logue 3 and the adduct 4 appear to have a more facile beta-hydrogen el imination pathway which makes them less suitable for the production of pure InP.