Synthesis and structural characterization of bis(2,2′-bpy)bis(azide)cobalt(III) nitrate dihydrate

The title complex [Co-III(2, 2' -bpy)(2)(N-3)(2)].NO3-2H(2)O was obtained by an auto-oxidization reaction of cobalt nitrate with 2, 2' -bpy and sodium azide in aqueous solution at room temperature, and violet single crystals were prepared in ethanol solution. The structure was determined by X-ray crystallography. The crystal is of triclinic, space group P (1) over bar with a = 8.285(4), b = 11.990(8), c = 12.596(7) Angstrom, alpha = 86.630(3), beta = 86.280(5), gamma = 71.130(10)degrees, C20H2CoN11O5, M-r = 553.40, Z = 2, V = 1180.6(12) Angstrom(3), F(000) = 568, D-c = 1.557 g/cm(3), mu = 0.784 mm(-1), R = 0.0403 and wR = 0.1008. The title complex consists of a [CoIII (2, 2'-bpy)(2)(N-3)(2)](+) cation, a NO3- anion and two lattice water molecules. The center Co-III ion coordinated by two chelating 2, 2'-bpy ligands and two terminal azide groups with a CoN6 coordination environment exhibits a distorted octahedral geometry.