A novel tetranuclear copper(II) complex with 3,5-pyridinedicarboxylate bridges

An unprecedented tetranuclear complex bridged by 3,5-pyridinedicarboxylate (abbreviated as 3,5-PDC) with an empirical formula [Cu-2(2 2'-bpy)(3)(3,5-PDC)](2)(ClO4)(4) . 2(H2O), has been synthesized and spectrally characterized. X-ray structural analysis reveals that there are two types of copper(II) centers, one is penta-coordinate with a distorted pyramidal geometry, while the other is tetra-coordinate with a distorted square planar geometry. 3,5-PDC serves as a tridentate ligand linking three adjacent metals with its one nitrogen and two monodentate carboxylic donors. (C) 2004 Published by Elsevier Ltd.