Article 32

Abstract

The Schiff base (LH 2) was prepared by the equimolar reaction of o-phenylenediamine with mhydroxybenzaldehyde under reflux conditions. The metal (II) complexes were prepared by reacting the Schiff base with the metal (II) salts of Fe, Co, and Cu. NMR, IR, UV/Vis, CHN elemental analysis and magnetic moments were used to characterize the compounds. The formulas of the metal complexes were proposed using CHN analysis. In the metal (II) complexes the bands due to υ (O-H) and v (C-O) were shifted to lower wavenumbers and the new medium band assigned to v(M-O)indicated the coordination of the ligand to the metal ions through the phenolate oxygen. In the UV region, the intra ligand π→π* (phenyl ring) and n→π* (-C=N) transitions appeared as medium bands at 299 and 316 nm in the ligand. The metal (II) complexes also exhibit these bands as well as d→d transitions, which suggested tetrahedral coordination of the ligands to the metal ions. The magnetic moments obtained supported the tetrahedral geometries for the paramagnetic metal complexes. The inhibitory activity of the test compounds against Staphylococcus aureus and Pseudomonas aeruginosa observably improved upon chelation. The ligand and metal (II) complexes exhibited better antifungal (12-18 mm) than antibacterial activity (8-18 mm).The positive controls, Gentamicin and Ketoconazole, showed diameters of zones of inhibition at 22-26 mm and 28 mm respectively.