The chemistry of Group 13/15 compounds (III-V compounds) with the higher homologues of Group 15, Sb and Bi

Sb(SiMe3)(3) reacts with R3M (R = Alkyl, M = Al, Ga, In) to form simple Lewis acid-base adducts R3M <-- SbR3'. Reactions with R2MCl (R = Me, Et, t-Bu) do not give uniform reaction products. Ga and In derivatives react under dehalosilylation to give heterocyclic compounds of the type [R2MSb(SiMe3)(2)](x) (x = 2, 3). In contrast, Me2AlCl leads to the formation of the six-membered heterocycle [Me(Cl)AlSb(SiMe3)(2)](3). Sterically more demanding diorgano aluminum halides Et2AlCl and t-Bu2AlCl form simple adducts R2AlCl <-- Sb(SiMe3)(3) (R = Et, t-Bu). Heterocycles of the type [R2AlSbR2'](x) (x = 2, 3) are obtained by dehydrosilylation reactions between dialkyl aluminum hydrides R2AlH (R = Me, Et, i-Bu) and R-2' SbSiMe3 (R ' = SiMe3, t-Bu). This reaction pathway also leads to the first synthesis of an organometallic bismuthide of Group 13 elements, Al, Ga and In. [Me2AlBi(SiMe3)(2)](3) is formed by reaction of Me2AlH with Bi(SiMe3)(3) and its structure, as determined by X-ray crystallography, clearly reveals the formation of a six-membered heterocycle in the solid state. Monomeric aluminum stibides R2AlSbR2' <-- dimethylaminopyridine (dmap) are synthesized by reaction of the corresponding heterocycles [R2AlSbR2'](x), with dmap. Pyrolyses of Ga and In adducts, as well as Ga and In heterocycles, yield nanocrystalline GaSb and InSb through a P-hydride elimination pathway. Detailed metalorganic chemical vapor deposition investigations also demonstrate the potential of Al-Sb heterocycles [R2AlSb(SiMe3)(2)](2) (R = Et, i-Bu) to produce AlSb thin films. In addition, GaSb can be prepared ill solution by a dehalosilylation reaction between GaCl3 and Sb(SiMe3)(3). Depending on the solvent and its boiling point, nanoscale GaSb crystallites are obtained. Both the particle size and the composition can be controlled by the solvent. (C) 2001 Elsevier Science B.V. All rights reserved.