Precursor chemistry of Group III nitrides - Part XVI. Synthesis and structure of monomeric penta-coordinated intramolecularly adduct-stabilized amidobisazides of aluminum, gallium and indium with an all-nitrogen coordinationsphere: OMCVD of GaN using (N-3)(2)Ga{N[CH2CH2(NEt2)](2)}

New intramolecularly Lewis-base-stabilized halogeno alanes, gallanes and in danes of the general formula (X)(2)M(N[(CH2)(n)(R')(2)](3)) (1-6) and (X)(2 )M(N(Et)[(CH2)(2)N(R')(2)]) (7-9) (n = 2, 3; R' = Me, Et; X = Cl, Br; E = A l, Ga and In) as well as the azido derivatives (N-3)(2)Ga(N[(CH2)(2)N(Et)(2 )]) (10) and (N-3)(2)Ga(N(Et)[CH2)(2)N(Me)(2)]) (11) as representative exam ples of the homologous series were synthesised via standard salt metathesis routes and fully characterised by means of elemental analysis, NMR and IR spectroscopy. Compounds 1, 2, 3 and 10 were studied by X-ray crystallograph y revealing monomeric structures in the solid state. Compound 10 allowed th e growth of crystalline GaN thin films on sapphire substrates at 750 degree s C in the absence of ammonia using the technique of organometallic chemica l vapour deposition at reduced pressure. The films were analysed by XRD and Raman spectroscopy showing a preferred orientation of the crystallites per pendicular to the c-plane of the sapphire substrate. (C) 2000 Elsevier Scie nce S.A. All rights reserved.