Synthesis and characterization of <img src='/image/spc_char/micro.gif' border=0>-phenoxo-bridged binuclear copper(II) complexes derived from binucleating ligands

Abstract

The new pentadentate binucleating symmetrical ligand 2,6-bis [N-(3,5-dichloro-2-hydroxybenzyl)-N-cyclohexylamino-methyl]-4-methylphenol (H₃L¹) has been prepared and its binuclear copper(II) complexes of the general formula [Cu₂L(X)], where X = OH (perchlorato counter ion complexes), OAc, NO₃ have been prepared. Their spectral properties and catecholase activities were studied. New unsymmetrical ligands and their complexes have also been synthesized. The phenolate oxygen atom of the binucleating ligands behaves as a bridging group. Conductivity studies showed that all the complexes are neutral. ESR spectra of the complexes show a broad band centred at 3500 G with no hyperfine splittings. The observed room temperature magnetic studies were found to be less than spin only value for d⁹ system. The rate constants of the complexes for the oxidation of catechol to <i style="">o</i>-quinone were in the range of 0.72<img src='/image/spc_char/cross.gif' border=0>10^-3 to 15.0<img src='/image/spc_char/cross.gif' border=0>10^-3 min^-1.