Abstract: The Schiff base consisted of 3,5-diiodo-salicylalidehyde and o-diaminobenzene(L) and its Ni(Ⅱ) metal complex has been synthesized and characterized by 1H NMR, elemental analysis, UV spectra, IR spectra and molar conductance analysis. The main bond parameters of the complex were calculated by full-optimized molecular geometry using Gaussian03 program. The composition of the complex was determined to be Ni(Ⅱ)L. The binding mode between complex and DNA was investigated by UV spectra, viscosities, and DNA competitive binding with ethidium bromide(EB). The results showed that the intensity of absorption peaks increased when the complex interacted with ct-DNA, and its constant was Kb=1.129×105 L/mol. The complex will lead to dramatic decrease of fluorescent intensity of EB-NA. The relative viscosity of ct-DNA increased with the concentration increase of the complex. All indicated that the complex was intercalated into ct-DNA. In addition, the complex is assayed against M.luteus by the punch method.

Key words: Iodine-containing Schiff base, Ni(Ⅱ) complex, spectrum character, DNA Intercalative binding mode, antibacterial activity