Synthesis, characterization and biological studies of sulfadiazine drug based transition metal complexes

Radha S, Mothilal K. K, Thamar

Abstract

The metal complexes of sulfadiazine drug have gained considerable importance due to their pronounced biological activity. A series of transition metal complexes of the above drug have been prepared and characterized by elemental analysis, molar conductance, electronic spectra, FT-IR, thermogravimetric analysis, proton NMR and cyclic voltammetry techniques. The electronic spectra of the ligand and complexes revealed the octahedral geometry for Ni(II) and Co(II)complexes and distorted octahedral geometry for Cu(II)complex. The corresponding infrared spectra suggest that the ligand behaves bidentate and confirm the presence of water molecules in the coordination sphere. The NMR spectral studies established changes in chemical shift of sulfa-imino proton and free –NH2group of ligand indicating complexation involving these groups. The thermal stability of the complexes has been studied by thermogravimetric and differential scanning calorimetry, which support the presence of water ligand and metal. The complexes exhibit an octahedral geometry around the metal Centre. The cyclicvoltammetric studies of the metal complexes showed that all but the cobalt complex exhibit an irreversible electron transfer redox processes. The cobalt complex, however, revealed a quasi-reversible behavior. The antimicrobial studies of synthesized metal complexes and ligand were screened for antibacterial activity against bacteria such as Escherchia coli, Staphylococcus aureus, Pseudomonousaureginosa and antifungal activity against P. Aeruginosa and Candida albicans species. Metal complexes of sulfadiazine drug exert a greater effect on the antimicrobial activities than the ligand drug