Crystal structure, spectroscopic characterisation and magnetic properties of [Cu(BIP)(N-3)]center dot H2O (BIP=3,3-bis(2-imidazolyl)propionate), a copper(II) polymeric compound with asymmetrical mu-1,3-azido bridges

The structure and the spectroscopic and magnetic properties of [3,3-bis(2-i midazolyl)propionato]azidocopper(II) monohydrate are described. The compoun d is built of [Cu(BIP)N-3] entities which are connected through carboxylate groups from the BIP molecules-which act as a tridentate ligand-and asymmet rical mu -1,3-azido bridges, leading to a polymeric sheet-like structure. T he copper atom is involved in a CuN3ON' chromophore and lies in a distorted square-pyramidal environment. Both electronic and EPR spectra are indicati ve of an essentially d(x 2-y 2) ground state for the copper(II) ions. Magne tic susceptibility measurements in the range 1.8-200 K show very weak antif erromagnetic exchange between the copper(II) ions (2J = -0.48 cm(-1)). This feat-are is discussed on the basis of the relative orientation of the coor dination polyhedron around the metal atom and the bridging network. (C) 200 1 Elsevier Science B.V. All rights reserved.