ANTIMICROBIAL STUDIES ON KNOEVENAGEL CONDENSATE β-DIKETONE COMPLEXES: SYNTHESIS AND CHARACTERIZATION

Abstract

Few novel Knoevenagel based metal (II) complexes were prepared by using Knoevenagel condensate β-diketone ligand (obtained by the condensation of acetylacetone and cinnamaldehyde) as primary ligand (L1) and 1,10-phenanthroline as co-ligand (L2). The proposed structure of these metal chelates have been characterized by elemental analysis, magnetic susceptibility, molar conductance measurements, UV-Vis., FT IR and 13NMR spectral studies. These complexes show higher molar conductance values, supporting their electrolytic nature. Spectroscopic and other analytical data of the complexes suggest square planar geometry around the central metal ion. The analytical data of the complexes accord well with the formula [ML1L2]Cl2; where M= Cu(II), Co(II), Zn(II) and Ni(II) ions..The antimicrobial activity of synthesized ligand and their complexes are tested against perceptive organisms such as two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and three Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae and Salmonella typhi) and five fungi (Aspergillus niger, Fusarium solani , Curvularia lunata, Rhizoctonia bataticola and Candida albicans). The complexes exhibit higher antimicrobial activities than free ligand and it has been investigated by Minimum Inhibition Concentration (MIC) method. Among the metal complexes, Cu (II) complex exhibit higher efficacy against all the pathogens.