SYNTHESIS STRUCTURAL CHARACTERIZATION, ANTIMICROBIAL AND CYTOTOXIC STUDIES ON SOME NOVEL TRANSITION COMPLEXES WITH NO BIDENTATE SCHIFF’S BASE LIGAND DERIVED FROM SULFAGUANIDINE WITH MOLECULAR ORBITAL CALCULATIONS

Some selected solid complexes of the Schiff base ligand HL derived from sulfa- guanidine with Cu(II), Ni(II), Co(II) and Zn(II) ions were synthesized and characterized by elemental analysis, FTIR, electronic, mass, and ESR spectral analyses, as well magnetic susceptibility, and molar conductance measurements. The disappearance of hydroxyl band ν(O-H) of the phenolic group, and the lowering shift of the stretching frequency of the ν(C=N) azomethine band in the ligand after complexation, indicate the coordination through the phenolic oxygen atom ( after deprotonation) and azomethine nitrogen atom of the Schiff base ligand HL. The lower values of molor conductance indicate the non-electrolytic nature of these complexes. The ESR spectrum of the copper complex of HL has octahedral geometry. The molecular structures were studied by PM3 method, also the heat formation, HOMO, LUMO and dipole moment were calculated to confirm the geometry of the ligand and the its complexes. The antimicrobial screening for the compounds underinvestigation HL and 1-4 was reported. The Schiff base ligand HL showed weaker to significant activity against some tested microorganisms. In the most cases, the increasing activity was exhibited upon coordination with metal (II)ions. In addition, calculated in silico, the pharmacokinetic parameters have promising futures for application of the ligand as drug.