SYNTHESIS, CHARACTERIZATION, AND ANTIMICROBIAL STUDIES OF SOME NOVEL TRANSITION METAL COMPLEXES WITH SCHIFF BASE LIGAND DERIVED FROM SULFONAMIDE

Some selected solid complexes of the Schiff base ligand HL derived from sulfa-guanidine with Ni(II), Co(II), Cu(II) and Zn(II) ions were synthesized and characterized by elemental analysis, FT IR, electronic, mass, TGA, DTA and ESR spectral analyses, as well as 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 molar conductance indicate the non-electrolytic nature of these complexes. The ESR spectrum of the copper complex of HL has tetrahedral 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 its complexes. The antimicrobial screening for the compounds under investigation HL and its complexes 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.