Author Details
Muraleedharan Nair. M.K*, Ajitha. P.S, Rejimon. P.K
Postgraduate & Research Department of Chemistry,
Maharaja’s College, Ernakulam – 682011, Kerala, India
E-mail : mkmuraleedharan@hotmail.com
ABSTRACT
Nitrogen–Oxygen donor ligands, 2,3-dimethyl-4-(iminopyridoxyl)-1-phenyl-3-pyrazoline-5-one (L1), 5-(hydroxymethyl)-4-{(1-Z)-[2-N(2-hydroxylphenyl]ethanimidoyl)-2-methyl}pyridine-3-ol-hydrochloride(L2), 5-(hydroxymethyl)-4-{(1-Z)-[2-N(3-hydroxyl-phenyl]ethanimidoyl)-2-methyl}pyridine-3-ol-hydrochloride (L3) have been synthesized. New lanthanide(III) complexes of the three ligands [La(L1)2(NO3)3] (a), [La(L1)2Cl2]Cl (b), [La(L1)2ClO4](ClO4)2 (c), [La(L2)2(NO3)2]NO3 (d), [La(L2)2Cl3] (e), [La(L2)2(ClO4)](ClO4)2 (f), [La(L3)2(NO3)2]NO3 (g), [La(L3)2)Cl3] (h) and [La(L3)2(ClO4)2]ClO4 are synthesized and characterized by elemental analysis, molar conductivity, magnetic susceptibility measurements and spectroscopic studies. L1 and L2 act as tridentate chelating ligand where as L3act as a bidentate chelating ligand. The three Schiff base ligands and their metal complexes have been screened for antibacterial activity against six bacteria (E.coli, B. cereus, B. subtilis, S. aureus, S.typhi and K. pneumonia) and four fungi (A.niger, F. moneliforme, Pleurotus sajor caju and S.acremonium.). The antimicrobial studies suggest that the Schiff base ligand L2 was inactive towards all tested bacteria and fungi while L1 and L3 show moderate activity towards a few bacteria and fungi. All metal complexes showed significantly enhanced antibacterial and antifungal activity against microbial stains in comparison with free ligands.
Key words: Complexes, antimicrobial, antifungal activity, antibacterial, Schiff base