Title : Synthesis, spectral characterization and biological studies of some transition metal complexes of an azo dye derived from phthalylhydrazide.
Abstract:
A novel heterocyclic azo derivative was synthesized by coupling diazotized 5-phthalylhydrazide with 2-naphthol. Microwave assisted synthesis was used for preparing the metal complexes. Unlike the classical method, this method required neither harsh conditions nor organic solvents and found to be eco-friendly. The ligand and the metal complexes of cobalt(II), nickel(II), zinc(II) and copper(II) were characterized on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, UV–vis, IR, 1H NMR and ESR. Spectral studies revealed that the ligand was coordinated to the metal ion in a tridentate fashion. The synthesis and photophysical characterization of new transition metal complexes with potential as long lifetime fluorescent probes of DNA structure and dynamics were reported recently. The fluorescence spectra of the ligand and the metal complexes in DMSO were recorded. In order to verify the quenching phenomenon of the metal complexes of azo dye the Time Correlated Single Photon Counting (TCSPC) measurements were conducted with the laser source at 300 nm. The average lifetime of the ligand and the metal complexes were also measured and it was observed in the range of 0.9-0.7 ns. From lifetime studies, it was obtained that binding a ligand to a metal in fact shorten the lifetime of the metal complexes. The DNA cleavage activity of the ligand and metal complexes were examined using gel electrophoresis. The copper(II) complex cleave DNA more efficiently in the presence of an oxidant than the ligand and other complexes.
