Synthesis, characterization and biological activity Screening of metal (ii) complexes of some nitrogen and dioxygen donor ligands.

Abstract

A series of Ni(II) and Cu(II) complexes of Schiff base ligands derived from 4-aminobenzoic acid, 2-aminophenol, salicylaldehyde and 1H-indole-2,3-dione have been synthesized and characterized by elemental analysis, FT-IR, UV-vis and NMR spectroscopic analyses. Elemental analysis data were in agreement with a metal:ligand ratio of 1:1 for the complexes formed with HL1, HL3 and HL4 in a tetrahedral geometry fashion while those with HL2 results in complexes with metal:ligand ratio of 1:2 in octahedral arrangement. The antimicrobial activity of the Schiff base ligands and their metal complexes were investigated on the strains of gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella typhi) as well as on the fungi strains (Candida albicans, Aspergillus niger, Rhizopus stolonifer and Penicillium notatum) using disc diffusion method. The results showed that the zones of inhibition of the metal complexes for both species were higher than that of the Schiff base ligands. This indicates that the metal complexes can be applied in drug design to control bacterial and fungal diseases.