Abstract

SYNTHESIS, CHARACTERIZATION, AND BIOLOGICAL EVALUATION OF SOME 3D-METAL COMPLEXES OF MACROCYCLIC LIGAND DERIVED FROM SUBSTITUTED CARBOHYDRAZONE AND THIOSEMICARBAZIDE MOIETY

Richa Kothari*

Abstract

The present paper deals with the synthesis and characterization of transition metal complexes of Schiff base derived from condensation of substituted carbohydrazone with thiosemicarbazide moiety in 1:1molar ratio. Using this tridentate ligand, complexes of Manganese (II), Cobalt (II), Nickel(II), Copper(II) and Zinc(II) complexes with general formula ML2 have been synthesized. The synthesized complexes were characterized by several techniques using molar conductance, elemental analysis, magnetic susceptibility, FT-IR spectroscopy, electronic spectra and mass spectra. The elemental analysis data suggest the stoichiometry to be 1 : 2 [M : L]. All the complexes are nonelectrolytic in nature as suggested by molar conductance measurements. Infrared spectral data indicate the coordination between the ligand and the central metal ion through sulfur and azomethine nitrogen atoms. Spectral studies suggest tetrahedral geometry for Mn(II), Ni(II) complexes, square pyramidal geometry for Cu(II) complex and distorted octahedral geometry for Co(II) and Zn (II) complexes. The pure drug, synthesized ligand, and metal complexes were screened for their anti-bacterial and anti-oxidant activities against gram positive and gram negative bacteria like E.Coli, S. aureus, P. aerogenosa, B. Subtilis species and ascorbic acid. It was observed that Schiff base and its metal complexes shows enhanced biological activity as compared to ligand or metal salts.

Keywords: Schiff base, Thiosemicarbazide moiety, Metal Complexes, substituted carbohydrazone, molar conductance, fluorescence spectroscopy, Invitro microbial activity and antioxidant activity.