Original Articles
Saadi MD Al-Nuzal and Adil HA
Abstract
Three Schiff base, 2-(4-dimethylamino)phenyliminomethyl phenol (L1), (2-hydroxy-benzylidene-amino)benzoic acid (L2), and 2,2-((4-nitrobenzene-1,2-iyl)bis(nitrilomethyl-yildene)diphenol (L3), has been synthesized from salicylaldehyde and N,N-dimethyl p-phenylene diamine, 2-amino benzoic acid, and 3-Nitro-o-phenylenediamine. The chemical structures of the Schiff-base ligand and their metal complexes were confirmed by various spectroscopic and physical techniques viz. UV-vis., FT-IR, 1H NMR, 13C NMR, ESI-mass spectra, elemental analysis, flame atomic absorption spectroscopy (FAAS), molar conductance, and magnetic susceptibility measurements. Metal complexes of the Schiff base were prepared from chloride salts of Co(II), Mn(II), Cu(II) and Zn(II) in an alcoholic medium. On the basis of elemental and spectral studies, six-coordinated geometry was assigned to these complexes. In the light of these results, it is suggested that these ligand acts as neutral and polydentate ligands, hence coordinates to metal atom through azomethine nitrogen and oxygen atoms of phenol groups, as well as the carboxyl group of 2-amino benzoic acid. The proposed geometry for these complexes were suggested according UV-visible and FT-IR spectrophotometry, molar variation method, and molar conductivity measurement: (1) [M( L1)(H2O)3Cl] for Mn(II) and Cu(II), (2) [Co( L1)2].2H2O for Co(II) and Zn(II), (3) [M(L2)2].2H2O for Co(II), (4) [Mn(L2)(H2O)2Cl][Et3N] for Mn(II), (5) [M(L2)(H2O)] for Cu(II), (6) [M(L2)(H2O)3] for Zn(II), (7) [Mn(L3)] for Mn(II), (8) [Co(L3)(H2O)2] for Co(II) and Cu(II), and (9) [Zn2(L3)Cl2(H2O)2] for Zn(II). The free Schiff base and their complexes have been tested for their antibacterial activity against Escherichia Coli (G-), Staphylococcus aureus (G+), and Pseudomonas aeruginosa (G-) by using Agar well diffusion and the results were discussed.