New Transition Metal Complexes with a Multidentate Schiff-base: Synthesis , Characterize and Biological studies

Abstract

5,5, '-(1 Abstract : The new polydentate Schiff-base ligand E,1'E)-(1,4-phenylene bis(methan-1-yl-1-ylidene))bis(azan-1-yl-1-ylidene)bis(1,3,4-thiadiazole-2-thiol) H2L and its binuclear metal complexes with Co(II) , Ni(II) and Cd(II) are reported. The reaction of thiosemicarbazide with anhydrous sodium carbonate in mole ratios of 1:1 gave the precursor 2-amino-5-mercapto-1,3,4-thiadiazole. Condensation reaction of precursor with Benzen1,4-dicarboxaldehyde in mole ratios of 2:1 gave the new N2S4 Schiff-base ligand H2L.The complexes were prepared from the reaction of the corresponding metal chloride with the ligand .The ligand and its metal complexes were characterised by spectroscopic methods (FTIR, UV-Vis,1H.NMR, A.A), chloride content, conductance and melting point measurements.These studies revealed tetrahedral geometries for Co(II) and Cd(II) complexes of general formulae [M2(L2)] and square planar for Ni(II) complex.Biological activity of the ligand and its metal complexes against gram positive bacterial strain Bacillus (G+) and gram negative bacteria Ecoli (G-) The effects of prepared compounds depend on the type of tested bacteria. It is clear that, the ligand and its metal complexes have a potential effect on the gram negative (G-) of the tested bacteria.