Synthesis, Characterization of New Copper Complexes of Thiosemicarbazone Derivatives and their Biological Activities

Abstract

Cu(II)complexes of ligand 2-[2-(4-chorophenylamino acetyl-N-phenyl hydrazine carbothioamide (H2L1) and 2-(4-methyl-chloro- phenylaminoacetyl- -N-phenyl hydrazine carbothioamide (H2L2) have been synthesized and characterized by using IR spectra, 1H NMR, elemental analyses, molar conductance, UV-Visible spectra, fluorescence spectra and thermal analysis (DTA/TG). The study revealed that the ligands behave as a neutral bidentate or monobasic bidentate or tridentate and coordination takes place via NH, C=O, and C-S. The thermal stability of the copper(II) complexes was investigated by thermogravimetry (TG), differential thermal analysis (DTA) techniques. Results were correlated to their structure. The thermal study revealed that Cu(II)complex(2) shows higher thermal stability as compared with all copper complexes. DNA binding properties of the copper(II) complexes with DNA have been investigated by absorption spectra and fluorescence spectra measurements. Results also showed that Cu(II) complex(1) exhibited chelating activity when incubated with isolated DNA. According to the electophoretic mobility, complex(1) showed the highest binding affinity with DNA and the observed enhancement of fluorescence may be utilized in sensing DNA. The anti-bacterial activities have also been studied, all complexes showed good anti-bacterial activity against gram positive and gram negative bacteria.