Sulfur-Containing Schiff Base Complexes of Iron(III) and Lead(II): Synthesis, Characterization, Antimicrobial Activity, and Their Electrochemical Behaviors

The sulfur–nitrogen donor ligands, thiosemicarbazones of 5-nitro-1H-indole-2,3-dione and 6-nitro-1H-indole-2,3-dione and 5-chloro-1H-indole-2,3-dione, have been prepared by the condensation of thiosemicarbazide with respective ketones in 1:1 molar ratio in ethanol medium. Lead and iron complexes were prepared by the reaction of lead(II) chloride and iron(III) chloride with the ligands in a 1:2 molar ratio, respectively. The newly synthesized complexes have been characterized by elemental analysis, melting point determinations, and UV, ESR, and IR spectral studies. In all the complexes, the monobasic bidentate nature of the ligand is evident. Based on analytical and spectral data, hexacoordinated structure for lead and pentacoordinated structure for iron complexes have been proposed. Antibacterial and antifungal studies of these compounds against various pathogenic bacterial and fungal strains have been carried out. One of the ligands and its metal complexes were screened for their antifertility activity. ...