Synthesis, characterization and DNA photocleavage study of a novel dehydroacetic acid based hydrazone Schiff’s base and its metal complexes

Abstract

A series of some novel colored complexes of Co(II), Ni(II), Cu(II), Mn(II) and Zn(II) with a novel dehydroacetic acid based hydrazone Schiff’s base has been synthesized and evaluated for their DNA photocleavage potential. The ligand utilized in the present investigation was synthesized via a condensation reaction between cyanoacetic acid hydrazide and dehydroacetic acid. Further, the ligand was treated with different metal acetates of first transition series in 1:1 and 1:2 (metal to ligand) ratios, respectively, to obtain metal complexes with different ligand to metal stoichiometry. Ligand as well as all the synthesized metal complexes were characterized on the basis of data obtained from the techniques like 1H and 13C NMR, IR spectroscopy, mass spectrometry, UV visible spectroscopy, elemental analysis and molar conductance. 1H NMR spectrum of Zn(II) complexes showed the coordination of enolic oxygen atom without deprotonation, but in case of DLCu, the deprotonation of enolic proton was occurred prior to coordination. IR data revealed the participation of a carbonyl oxygen atom of ligand in coordination with metal ions. UV visible data confirmed the square-planar and octahedral geometry of the complexes. Mass spectrum showed the formation of both 1:1 and 1:2 metals to ligand stoichiometry. Most of metal complexes exhibited very good DNA photocleavage activities.