Molecular precursors to group 13 nitrides, 14 Synthesis and structures of (N-3)(2)Ga[(CH2)(3)NMe2], (N-3)Ga[(CH2)(3)NMe2](2) and (N-3)(3)Ga(NR3) (R =CH3, C2H5)

The synthesis, properties and X-ray single crystal structure analysis of th e intramolecularly adduct-stabilised organogallium bisazide (N-3)(2)Ga[(CH2 )(3)NMe2] (1), the mono azide (N-3)Ga[(CH2)(3)NMe2](2) (2) and the trialkyl amine adducts of triazidogallium of the type (N-3)(3)Ga(NR3) (3a-d; R = alk yl) are reported. An unusual isomer Ib of compound 1 is described, which wa s obtained by slow cooling of the analytically pure neat liquid compound 1 to 0 degrees C. The new and unusual structure Ib can be regarded as a weak associate of dimers linked together by head-to-tail azide bridges. In contr ast, compounds 2 and 3a-b (R = CH3, C2H5) are monomeric in the solid state. The suitability of the volatile compounds 1 and 2 as single source precurs ors to grow GaN thin films by chemical vapour deposition is compared, showi ng that preferentially oriented crystalline films can be obtained from comp ound 2 on sapphire substrates at 600-700 degrees C in vacuo (0.1 Pa). Howev er the films have a grey rather than a transparent appearance, which is pre sumably due to N-deficiency owing to the lower N-content of the single mole cule precursor 2 relative to 1.