Reactivity of GaX3 with silylamines and thermal decomposition of the compounds [Cl2Ga{NH(SiMe3)}]2 and [Cl3Ga{NH(SiMe3)2}]

Abstract

The Lewis acid/base adducts [X₃Ga{NH(R)(R′)}] (X = Cl, R = R′ = SiMe₃ (1), SiMe₂Ph (2) and R = Bu^t, R′ = SiMe₃ (3); X = Br, R = R′ = SiMe₃ (4) or SiMe₂Ph (5)) were synthesised by the 1 ∶ 1 reaction of GaX₃ with NH(R)(R′) in hexane solution at room temperature. Dimeric complexes, of the type [X₂Ga{NH(R)}]₂ (X = Cl, R = SiMe₃ (6), R = SiMe₂Ph (7) and R = Bu^t (8); X = Br, R = SiMe₃ (9)) were prepared by the 1 ∶ 1 reaction of GaX₃ with NH(R)(R′) in CH₂Cl₂ solution. Compounds 1 and 8 have been structurally characterised. Polycrystalline GaN was obtained from the pyrolysis of compounds 1 and 6 under inert conditions (N₂, vacuum) above 500 °C, as shown by the X-ray powder diffraction patterns.