Syntheses, Characterization, Antimicrobial and DNA Cleavage Activity of Cr(III) Complexes with Coumarin based Schiff Base Ligands

Abstract

A series of biologically important complexes of chromium(III) have been synthesized by the reaction of 3-formyl-4-chlorocoumarin hydrazinecarbothioamide (L¹H) and 3-formyl-4-chlorocoumarin hydrazinecarboxamide (L²H) with CrCl₃·6H₂O in 1:1 and 1:2 molar ratio. All the complexes have been characterized by elemental analysis, molecular weight determination, melting point, conductivity measurements, electronic, IR, ¹H NMR, ¹³C NMR and EPR spectroscopic techniques and X-ray diffraction. In vitro biological screening effects of the compounds were tested against the pathogenic bacterial and fungal species. Further, free ligands and their metal complexes have been screened for their DNA cleavage activity. A comparative study of the biological activities of the Schiff base ligands and their Cr(III) complexes indicates that the complexes exhibit higher antimicrobial and DNA cleavage activity than the free ligands. Physico-chemical studies and spectral data suggested a hexa-coordinated environment around the central metal ion.