SPECTROSCOPIC, THEORETICAL AND BIOLOGICAL STUDIES OF BINUCLEAR Mn(II), Ni(II), Cu(II) AND Cd(II) COMPLEXES WITH POLYDENTATE LIGAND DERIVED FROM DEHYDROACETIC ACID AND DIETHYLENETRIAMINE

Abstract

A series of binuclear acyclic polydentate complexes of Mn(II), Ni(II), Cu(II) and Cd(II) ions with a ligand derived from the condensation of dehydroacetic acid and diethylenetriamine (3,3'-[iminobis(ethane-2,1-diylnitrilo-(1E)-eth-1-yl-1-ylidene)]bis(4-hydroxy-6-methyl-2H pyran-2-one)]), [Mn2LCl2(H2O4)] and [M2LCl2], M=Ni, Cd and Cu(II), have been prepared and characterized by1H and 13C NMR, FT-IR and UV-Visible spectroscopy and micro-elemental analysis, as well as with the measurement of the magnetic moments of solid complexes and molar conductivity in DMSO solution. The new acyclic poly dentate ligand 3,3'-[iminobis(ethane-2,1-diylnitrilo-(1E)-eth-1-yl-1- ylidene)]bis(4-hydroxy-6-methyl-2H-pyran-2-one)] are identified on the basis of (CHN) elemental analysis, 1H, 13C NMR, as well as FT IR and UV-Visible spectroscopy. The antimicrobial activity of the free ligand and its Mn(II), Ni(II), Cu(II) and Cd(II) complexes were tested against Staphylococcus aureus and Escherichia coli and fungicidal activity against Aspergillus Niger and Candida albicans. The minimum inhibitory concentration (MIC) method revealed that all metal complexes showed enhanced activity toward the selected micro-organisms compared with the free ligand H2L and Amoxicillin. The octahedral geometry is proposed for Mn(II) complex, square planar for Ni(II) and Cu(II) complexes and tetrahedral symmetry is suggested for Cd(II) complex