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 Lew is 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 d ehalosilylation to give heterocyclic compounds of the type [R2MSb(SiMe3)(2) ](x) (x = 2, 3). In contrast, Me2AlCl leads to the formation of the six-mem bered heterocycle [Me(Cl)AlSb(SiMe3)(2)](3). Sterically more demanding dior gano 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 h ydrides 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 bi smuthide of Group 13 elements, Al, Ga and In. [Me2AlBi(SiMe3)(2)](3) is for med by reaction of Me2AlH with Bi(SiMe3)(3) and its structure, as determine d 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 correspondi ng heterocycles [R2AlSbR2'](x), with dmap. Pyrolyses of Ga and In adducts, as well as Ga and In heterocycles, yield nanocrystalline GaSb and InSb thro ugh a P-hydride elimination pathway. Detailed metalorganic chemical vapor d eposition investigations also demonstrate the potential of Al-Sb heterocycl es [R2AlSb(SiMe3)(2)](2) (R = Et, i-Bu) to produce AlSb thin films. In addi tion, GaSb can be prepared ill solution by a dehalosilylation reaction betw een GaCl3 and Sb(SiMe3)(3). Depending on the solvent and its boiling point, nanoscale GaSb crystallites are obtained. Both the particle size and the c omposition can be controlled by the solvent. (C) 2001 Elsevier Science B.V. All rights reserved.