SBDTC Derived Schiff Base Metal Complexation: Synthesis, Physicochemical, and Spectral Studies with Antibacterial Activity

A Schiff base ligand derived from condensation of S-benzyldithiocarbazate (SBDTC) and salicylaldehyde, and its U(VI), Th(IV) and Zr(IV) complexes have been synthesized. The compounds are characterized by elemental analysis, molar conductance, magnetic moments, UV-Vis, FT-IR and 1H NMR spectra. The Schiff base ligand coordinates via azomethine nitrogen, thiol sulfur and/or the phenolic OH group, and acts as bidentate in case of U(VI) and Zr(IV) ions and tridentate with Th(IV) ion. The U(VI) and Th(IV) complexes are 1 : 2 electrolytes whereas Zr(IV) complex is non-electrolytic. All the compounds have been tested for their antibacterial activity against four pathogenic bacteria, two Gram-negative Escherichia coli and Shigella dysenteriae and two Gram-positive Staphylococcus aureus and Bacillus subtilis using Kanamycin (K-30) as a standard. The U(VI) and Th(IV) complexes exhibit stronger antibacterial activity than the Zr(IV) complex against all tested organisms.