PREPARATION OF NEW SERIES OF TETRADENTATE SCHIFF BASE COMPLEXES AND STUDING THEM SPECTROSCOPICALLY, BIOLOGICALLY AND THEORETICALLY

Abstract

This new Schiff base ligand (L) were prepared from condensation reaction of 3-amino-4-(1-methoxy-1-oxo-3-phenylpropan-2-ylamino)-4-oxo butanoic acid(aspartame) with 4-(dimethyl amino benzaldehyde). A series of complexes of divalent, trivalent and tetravalent ions were prepared. The ligand and the prepared complexes of cobalt, nickel, copper, palladium, platinum and gold have been characterized by several techniques such as C.H.N.O, FT-IR, molar conductivity, UV– visible, magnetic moment, ¹H-NMR and ¹³C-NMR. Experimental findings demonstrated that the ligand formed tetra-dentate coordination with the metal ions. The biological activity was studied by using two types of gram positive Staphylococcus aureus, Bacillus subtilis, and gram negative bacteria E. coli, Klebsiella with one type of fungi candida at a concentration of 0.02 M. The results showed that the prepared metal complexes and ligand are more effective than the standard drug in bacteria and fungi. The molar ratio method was used to calculate the ratio of metal to ligand. The experimental results have proven its interaction in a ratio of (1:1). Additionally, the hyper-Chem 8.0.7 program was used to calculate the binding energy and the standard heat of formation of the ligand(L) and all prepared complexes, in addition to calculating the vibration frequency of the ligand, also HOMO and LUMO.