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

Abstract

Complexes of Cu(II) with N,N′-bis(3-carboxy-1-oxopropanyl)-1,2-ethylenediamine(C 10H 16N 2O 6,L 1), N,N′-bis(3-carboxy-1-oxopropanyl)-1,2-phenylenediamine(C 14H 16N 2O 6,L 2), N,N′-bis(2-carboxy-1-oxophenelenyl)-1,2-phenylenediamine(C 22H 16N 2O 6,L 3) and N,N′-bis(3-carboxy-1-oxoprop-2-enyl)-1,2-phenylenediamine(C 14H 12N 2O 6,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 MO 4 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.