Synthesis, Spectroscopic Characterization, Thermal Investigation and Antimicrobial Activity of S, O and N-Donor Heterocyclic Schiff Base Ligands and their Co(II), Cd(II), Hg(II), Fe(III) and UO2(II) Metal Complexes

THE POLYDENTATE ligands 2,5-N, N-bis (dimethyl-1. phenyl-4-pyrazoline-5-one) furanidine; 2,5-N, N-bis (pyridine) furanidine and 2,5-N, N-bis (2-thiophenol) furanidine (L-1 -L-3), have been prepared and identified. The chemical behavior of these ligands towards some metal cations such as Co(II) Cd(II), Hg(II), Fe(III) and UO2(II) was studied. The isolated complexes are characterized using analytical data, IR, 1H-NMR, UV-visible, mass spectroscopy, magnetic susceptibility, thermal analysis and molar conductance measurements. Bonding of the ligands with the metal ions is deduced from IR spectra and the presence of the mononuclear complexes are inferred from the mass spectral study. An octahedral structure is proposed for the prepared metal complexes and some ligand field parameters (D-q, B, and beta) in addition to LFSE were calculated from electronic spectral data. All synthesized compounds were screened for their antimicrobial activity against gram positive and gram negative bacteria and fungi. The biological evalution study showed high to moderate bacterial activity compared with the ligands, their metal complexes and known antibiotics data.