Synthesis, characterisation, DNA binding, cleavage and antibacterial studies of NiII, CuII and ZnII complexes of 2,4-dichloro-N-((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene)benzohydrazide

Department of Chemistry, Nizam College, Osmania University, Basheerbagh, Hyderabad-500 001, Telangana, India Department of Chemistry, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad-500 085, Telangana, India E-mail: vrr9@yahoo.com Manuscript received 26 February 2017, revised 13 March 2018, accepted 23 March 2018 Three mononuclear complexes of NiII, CuII and ZnII metal ions (M) with 2,4-dichloro-N-((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene)benzohydrazide (L) have been synthesized and characterized by elemental analysis, mag­netic susceptibility measurements, molar conductance, IR, 1H NMR, TGA, UV, LC-MS and ESR spectral studies. The ana­lytical and spectral data suggest that the ligand is tridentate and is coordinating to the metal ions through O, N, O donor atoms. The DNA binding behaviour of the complexes were studied by electronic absorption spectroscopy, fluo­rescence spectroscopy and viscosity measurements. It was found that the complexes bound to Calf thymus DNA through intercalative mode. The DNA cleavage activity of complexes was studied using of plasmid pBR322 DNA. The antibacte­rial studies were carried out against Gram-positive and Gram-negative bacteria, the results showed the metal com­plexes to be more active than the ligand