Copper(II) complexes of new biomimetic polydentate amide ligands: a spectroscopic study

Complexes of Cu(II) with N,N'-bis(3-carboxy-1-oxopropanyl)-1,2-ethylenediamine(C10H16N2O6,L-1), N,N'-bis(3-carboxy-1-oxopropanyl) -1,2-phenylenediamine(C14H16N2O6,L-2), N,N'-bis(2-carboxy-1-oxophenelenyl)-1,2-phenylenediamine(C22H16N2O6,L-3) and N,N'-bis(3-carboxy-1-oxoprop-2-enyl)-1,2-phenytenediamine(C14H12N2O6,L-4) have been prepared and characterised by elemental analyses, vibrational spectra, magnetic susceptibility measurements, ligand field spectra, EPR spectra, thermal studies and X-ray diffraction spectra. Vibrational spectra indicate coordination of amide and carboxylate oxygens of the ligands giving a MO4 square planar chromophore. Ligand field and EPR spectra support square planar geometry around Cu(II). [Cu(L-1)] complex has the maximum activation energy and [Cu(L-3)] complex has the minimum activation energy. (C) 2004 Elsevier B.V. All rights reserved.