Synthesis, magnetic and spectral studies of chromium(III), manganese(III), iron(III) and cobalt(III) complexes of thiosemicarbazones derived from benzil α-monoxime and unsubstituted/substituted thiosemicarbazides as biological agents

Abstract

Cr(III), Mn(III), Fe(III) and Co(III) complexes of thiosemicarbazones, derived from benzil α-monoxime and thiosemicarbazides (BMTH₂), benzil α-monoxime and phenyl thiosemicarbazides (BMPTH₂), benzil α-monoxime and 4-bromophenyl thiosemicarbazides (BMBTH₂), benzil α-monoxime and 4-chlorophenyl thiosemicarbazides (BMCTH₂) and benzil α-monoxime and 4-nitrophenyl thiosemicarbazides (BMNTH₂), have been prepared. These complexes have been characterized by elemental analyses, magnetic susceptibilities, molar conductance measurements, electronic, IR, ¹H and ¹³C NMR spectra (in the case of Co(III) complexes), FAB mass spectra and thermogravimetric analysis to arrive at the geometry of the ligand environment around the metal ion and to elucidate the bonding sites of the ligands with the central metal. The complexes contain two monoprotonic tridentate ligands with NNS donor sites. Coordination to metal ion the oxime nitrogen, imine nitrogen and thione sulfur is confirmed in the complexes by IR spectral studies. The antifungal and antibacterial activities of the ligands and complexes have been screened.

Keywords:

• Thiosemicarbazones
• Mononuclear complexes
• Spectral
• Biological activity

Acknowledgements

We are grateful to the Council of Scientific and Industrial Research, New Delhi, India for financial assistance.