Synthesis, X-ray structure and magnetic properties of trinuclear copper(II) tridentate Schiff base complexes containing a partial cubane Cu3O4 core

Two copper(II) complexes with tridentate Schiff bases AE and SE, which are condensed from N,N-dimethylethylenediamine and acetylacetone or salicylaldehyde, respectively, have been synthesized, characterized by X-ray structural analysis, magnetic measurement, IR and UV spectra. Both of the complexes contain a partial cubane CU3O4 core consisting of [Cu(AE)] or [Cu(SE)], nonbonded ClO4- anions and water molecules. The two complexes comprise three [Cu(AE)] or [Cu(SE)] subunits, respectively, which are interconnected through two types of oxygen bridges afforded by the oxygen atoms of the ligands and the central OH- group. The average Cu-O distances involving hydroxy OH- are 2.053 Angstrom in complex 1 and 2.078 Angstrom in complex 2. Complex I exhibits an antiferromagnetic interactions between the copper ions with J= -2.40 cm(-1) and g = 2.038. Complex 2 exhibits a ferromagnetic interaction between the copper ions with J = 7.83 cm and g 2.02. (C) 2003 Elsevier Ltd. All rights reserved.