Preparation and Antibacterial Activity of Copper and Cobalt Complexes of 4-Chloro-3-nitrobenzoate with a Nitrogen Donor Ligand

Copper and. cobalt complexes with 4-chloro-3-nitrobenzoate (C1NBz) and the nitrogen ligands 1, 3-diaminopropane (1, 3-DAP) or o-phenylenediamine (o-PDA), were prepared and characterized. The complexes [Cu(C1NBz)2(1, 3-DAP)] (1), [Cu(C1NBz)(o-PDA)]Cl (2), [Co(C1NBz)2(1, 3-DAP)] (3) and [Co(CINBz)2(o-PDA)21 (4) were characterized by FTIR, UV-Visible absorption, elemental analysis and thermal analysis. Complex [Cu(C1NBz)(o-PDA)1CI (2) shows high antibacterial activity as indicated by its ability to inhibit the growth of Staphylococcus aureus, Enterococcus faecalis. Carboxylate ligand are of great interest due to their various coordination modes to transition metals. 1-4) Mononuclear carboxylate copper and nickel complexes in the presence of nitrogen donor ligands have been isolated in neutral or cationic form. 5-9) The antifungal and antibacterial properties of a range of copper(II) complexes have been evaluated against several pathogenic fungi and bacteria. 10-13) In addition to its ability to combat infection or neoplastic disease, an antibiotic must exhibit selective toxicity, chemical stability, and optimun rates of bio-transformation and elimination. 14, 15) In this paper we report the synthesis of copper(II) and cobalt(II) complexes with mixed ligands: 4-chloro-3-nitrobenzoic acid (C1NBz) and 1, 3-diamino propane (1, 3-DAP) or o-phenylenediamine (o-PDA). The antimicrobial efficiency of the complex (2) [Cu(C1NBz)(o-PDA)]Cl has been tested on four different bacteria.