Coordinating behaviour of 3-methyl[1,2,3]triazolo[1,5-a]pyridine (tzpy):: crystal and molecular structure and electronic properties of [Cu(tzpy)2(ONO2)2(OH2)]

The crystal and molecular structure of [Cu(tzpy)(2)(ONO2)(2)(OH2)] (tzpy = 3-methyl[1,2,3]triazolo[1,5-a]pyridine) has been determined by X-ray diffraction methods. The crystal structure is built up of discrete [Cu(tzpy)(2)(ONO2)(2)(OH2)] entities linked through hydrogen bonds. The coordination geometry around the copper atom can be described as an elongated and strongly distorted octahedron displaying a 4 + 1 + 1* coordination mode (CuN2O2O'O " chromophore) with one of the nitrate groups acting as bidentate and involved in a weak off-the-z-axis coordination. Spectroscopic properties are interpreted on the basis of the above stereochemistry. (C) 1999 Elsevier Science Ltd. All rights reserved.