Tetraazido complexes of aluminium, gallium, and indium

The new tetraazido complexes of aluminium, gallium, and indium [thf(2)Na][t hf(2)Al(N-3)(4)] (1), [py(2)Na][py(2)In(N-3)(4)] (2), and Na[Ga(N-3)(4)] (3 ) have been synthesized from MCl3 and NaN3 by salt metatheses and character ized by X-ray diffraction analysis. In compounds 1 and 2, the Group 13 meta l atom and the sodium atom are each hexacoordinated by four azido groups an d two additional solvent molecules. The azido groups act as mu(1,3)-bridgin g ligands between the Group 13 metal and sodium, thereby forming network st ructures. In contrast, complex 3 is solvent-free and exhibits a tetracoordi nated gallium centre and a heptacoordinated sodium atom. The structure of 3 has also been investigated by means of X-ray powder data and the Rietveld method and the results are compared with the single-crystal data.