SYNTHESIS, CHARACTERIZATION AND THEORETICAL TREATMENT OF SANDWICH SCHIFF BASES COMPLEXES DERIVED FROM SALICYLALDEHYDE WITH SOME TRANSITION METALS AND STUDY OF ITS BIOLOGICAL ACTIVITY

Abstract

Cobalt (II),Nickel (II) and Copper (II) complexes of Schiff Bases derived from Salicylaldehyde and 3,3'-diamino-diphenyl methane (L1), 3,3'-diaminodiphenyl ether (L2), 3,3'-diamino-diphenyl Sulphone (L3), were prepared and characterized by different analytical and spectral methods : elemental analysis, IR, UV-VIS, atomic absorption, Molar conductivity measurements, molar ratio studies and melting points. The Schiff bases behave as neutral tetra dentate ligands. The chloro – complexes ligands (L1, L2 and L3) with (2:2) Molar ratio showed a Sandwich structural. All complexes display an octahedral geometry around the metal center. Conductance data of the complexes suggested them to be non-electrolytes. A theoretical treatment of the formation of complexes in the gas phase was studied, this was done using the HYPERCHEM-6 program for the Molecular mechanics and Semi-empirical calculations. The free ligand and its complexes have been tested for their antibacterial activities against Two type of human pathogenic bacteria:(Staphylococcus aureus),(Escherichia coli ). the first group are Gram positive while the second group are Gram negative (by using agar well diffusion method). Finally,it was found that compounds show different activity of inhibition on growth of the bacteria.