Two new end-on azido bridged dinuclear copper(II) and cobalt(III) complexes derived from the (E)-N′-((pyridin-2-yl)methylene) acetohydrazide Schiff base ligand:: Characterisation, crystal structures and magnetic study

Metal complexes of Schiff bases derived from an aromatic hydrazide are well characterised and have been reported several times. Single crystal structures of metal hydrazone complexes derived from an aliphatic hydrazide are very rare and still remain unexplored. In this paper we report two new end-on azido bridged dinuclear copper(II) and cobalt(III) hydrazone complexes derived from an aliphatic hydrazide. The Schiff base [LH = CH3C(O)NHN=CHC5H4N] has resulted from the condensation of acetic hydrazide and pyridine-2-carboxaldehyde. The ligand and the complexes [Cu-2(L)(2)(mu(1,1)-N-3)(2)] (1) and [Co-2(L)(2)(mu(1,1)-N-3)(2)(N-3)(2)] (2) are characterised by elemental analysis, IR and UV-Vis spectral studies and in addition mass spectroscopy has been also carried out for LH. The structures of 1 and 2 have been established by X-ray crystallography. Variable temperature magnetic susceptibility measurement studies of 1 indicate the chi T-M values remain constant in the whole range of temperature 10 to 300 K at a value close of 0.75 cm(3) K mol(-1), which is in good agreement with the one expected for two uncoupled copper(II) centers. (C) 2008 Elsevier Ltd. All rights reserved.