Antioxidant, In-vitro Antibacterial and DNA-cleavage activities of Nickel (II) Complex derived from N, N'-(1, 2 Phenylenebis (Methanylylidene)) bis(4-Nitroaniline)

New mononuclear Nickel (II) complex with Schiff base derived from the condensation of o-phthalaldehyde with p-nitroaniline were synthesized. The ligand and its complex were characterized by elemental analysis, molar conductivity, magnetic moment, IR, 1H NMR, and electronic spectra. The conductivity data confirmed the non-electrolytic nature of the complex. The spectral and analytical data suggested a distorted octahedral geometry for Ni(II) complex. The synthesized complex with ligand have been screened for antimicrobial activity against two gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram-negative bacteria (Escherichia coli and klebsiella pneumoniae). The obtained results showed that Ni(II) complex is more potent than free ligand. DNA cleavage studies of Ni(II) complex have been investigated by gel electrophoresis using super coiled pUC18DNA. The experimental results revealed that the Ni(II) complex cleaved pUC18DNA. in an efficient manner than the parent ligand. In addition, the antioxidant activity of the ligand and its metal complex were investigated through scavenging effects for DPPH radical indicating that the compound show stronger antioxidant activity than free ligand but lower when compared to standard oxidants such as vitamin C. Keywords: Mononuclear, Antimicrobial studies and DNA cleavage.