Abstract
New mono- and binuclear copper(II) complexes with Schiff bases derived from the condensation of 2-amino-5-substituted-aryl-1,3,4-thiadiazole with substituted aryl aldehydes were synthesized. The complexes were characterized by elemental analyses, molar conductivity, magnetic moment, IR, H-1 NMR, electronic, ESR and mass spectrometry as well as thermal analyses. The conductivity data of the complexes confirmed their non-electrolytic nature. An octahedral geometry was suggested for complex 1, square-planar geometry proposed for complex 2 and square pyramidal structure suggested for complexes 3-7. The 3D molecular modeling of a representative complex was carried out on a CS Chem 3-D Ultra Molecular Modeling and Analysis Program. The synthesized complexes and ligands were screened in-vitro for their antimicrobial activity against gram-positive bacteria (Staphylococcus aureus), gram-negative bacteria (Escherichia coli) and fungi (Aspergillus flavus and Candida albicans). In most cases, metallation increased the antimicrobial activity compared with the free ligands. Also, the catalytic effect of the prepared complexes on the cathodic reduction of oxygen was studied.