Formation, Structural Characterization, and Thermal Decomposition of the Adducts X3Ga·P(SiMe3)3 (X = Cl, Br, I)

The adducts X 3 Ga·P(SiMe 3 ) 3 [X = Cl ( 1 ), Br ( 2 ), I ( 3 )] were prepared in high yields from the combination of the respective gallium trihalides with P(SiMe 3 ) 3 in hydrocarbon solvents at ambient temperature. The adducts were characterized by NMR, MS, elemental analysis, and single-crystal X-ray structure determinations. Particularly, the 1 H NMR study of 1 − 3 helped to correct our previously published results regarding monomer−dimer equilibria of the related [X 2 GaP(SiMe 3 ) 2 ] 2 in solution. The crystal structure determinations showed that 1 and 2 were solvated, 1 ·C 6 H 5 Cl and 2 ·C 7 H 8, respectively, and that 3 was solvent-free. The thermal decomposition of 1 − 3 was studied by TGA along with a determination of the volatiles from pyrolysis and analysis of the final solid product. The pyrolyses of 1 − 3 at 450 °C under vacuum resulted mainly in nanocrystalline GaP with 4−5 nm particle average sizes as determined by X-ray powder diffraction (XRD) and, for pyrolysis of 2, by transmission electron microscopy (TEM); in addition, small quantities of amorphous Si/C/H containing phases were also formed.