Metal complexes of the type [Ni(HIm)(4)(4-NO(2)pcyd)(2)]center dot CH3OH, 1, [Ni(bpy)(2)(4-NO(2)pcyd)(2)]center dot CH3CH2OH, 2, [Ni(phen)(2)(4-NO(2)pcyd)(2)]center dot CH3OH, 3, (HIm = Imidazole, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, 4-NO(2)pcyd = 4-nitro phenylcyanamide) have been studied. The synthesis and characterization of complexes 1 and 2 and the biological activities of 1-3 have been investigated. The geometries of ligand 4-NO(2)pcyd, complexes 1 and 2 were confirmed by single crystal X-ray crystallography. The interaction of 1-3 with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) was investigated using UV-visible and fluorescence spectrophotometric methods. The photo induced cleavage studies show that the complexes possess photonuclease property against pUC19 DNA under UV-visible irradiation. The in vitro antimicrobial activity and cytotoxic potential of all the complexes were examined. (C) 2016 Elsevier B.V. All rights reserved.