Synthesis, spectral characterization and biological studies of Cu (II), Co (II) and Ni (II) complexes of azo dye ligand containing 4‒amino antipyrine moiety

Abstract

A series of biologically active azo dye ligands, HL1 and HL2 have been synthesized by conventional diazo-coupling reaction at 0–5 °C. The synthesized azo dye ligands were utilised for metallization with different metal salts like Cu (II) Co (II) and Ni (II) in1:1stoichiometric ratio as ligand: metal. The structural features of the synthesized compounds were established by spectral (FTIR, 1H NMR, 13C NMR, LC-MS, UV–vis, ESR, powder XRD) elemental analysis, magnetic susceptibility and molar conductivity studies. On the basis of physicochemical and spectroscopic data, the octahedral geometry is assigned for all the metal complexes. The molar conductivity measurement proved that all the complexes are non-electrolytic in nature. Thermal decomposition confirmed the existence of lattice and the coordinated water molecule in the complex. The binding studies of all the synthesized complexes against CT-DNA suggest that the intercalation binding mode. A DNA nuclease activity exhibited that all compound cleaved pBR322 DNA in an efficient manner. Consequently, the anticancer activities of the new complexes were tested against A-549 (lung carcinoma), MDA-MB 231 (breast adenocarcinoma) and HEK293 (normal embryonic kidney) cells were assessed by MTT assay.