Synthesis and antimicrobial activities of metal(II) complexes with bis(2,4-diiodo-6-propyliminomethyl-phenol)-pyridine

Seven new mononuclear complexes have been synthesized from 2,4-diiodo-6-propyliminomethyl-phenol in pyridine and Cu(OAc)2 center dot H2O, Ni(OAc)2 center dot 4H2O, Co(OAc)2 center dot 4H2O, Zn(OAc)2 center dot 2H2O, Cd(OAc)2 center dot 2H2O, Mn(OAc)2 center dot 4H2O, and Hg(OAc)2. The complexes were characterized by UV, IR, ESI-MS, and elemental analyses; bis(2,4-diiodo-6-propyliminomethyl-phenol)-pyridine-copper(II) (1) was characterized by X-ray crystallography. The central metal in each complex is five-coordinate by two nitrogens and two oxygens from two 3,5-diiodosalicylaldehyde Schiff-base ligands and one nitrogen from pyridine. The 3,5-diiodosalicylaldehyde Schiff base is bidentate. All the complexes were assayed for antibacterial (Bacillus subtilis, Staphylococcus aureus, Streptococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Enterobacter cloacae) activities by the MTT method. Complex 1 showed the most favorable antimicrobial activity with minimum inhibitory concentrations of 6.25, 3.125, 6.25, 3.125, 6.25, 3.125 mu g mL-1 against B. subtilis, S. aureus, S. faecalis, P. aeruginosa, E. coli, and E. cloacae, respectively.