Résumé:
Three mixed complexes having formula [Cu(INAP)L(H2O)2] where INAP = deprotonated isonitrosoacetophenone
and L = deprotonated amino acid such as histidine, phenylalanine and tryptophan have been
synthesized. They have also been characterized using elemental analyses, molar conductance, UV–Vis, IR
and ESR spectra. The value of molar conductance indicates them to be non-electrolytes. The spectral studies
support the binding of the ligands with two N and two O donor sites to the copper (II) ion, giving an
arrangement of N2O2 donor groups. Density Functional Theory (DFT) calculations were applied to evaluate
the cis and trans coordination modes of the two water molecules. The trans form was shown to be
energetically more stable than the cis one.
The ESR data indicate that the covalent character of the metal–ligand bonding in the copper (II) complexes
increases on going from histidine to phenylalanine to tryptophan.
The electrochemical behavior of the copper (II) complexes was determined by cyclic voltammetry
which shows that the chelate structure and electron donating effects of the ligands substituent are
among the factors influencing the redox potentials of the complexes.
The antimicrobial activities of the complexes were evaluated against several pathogenic microorganisms
to assess their antimicrobial potentials. The copper complexes were found to be more active against
Gram-positive than Gram-negative bacteria
