A Novel Copper(Ⅱ) Complex of Asymmetrically N-Functionalized 1,4,7-Triazacyclononane Ligand: Syntheses,Structure, Electrochemical Property and Biological Activities

A novel copper(Ⅱ) complex derived from 1,4,7-triazacyclononaneCuL]_2(PF_6)_3×MeCN×H_2 O was synthesized and crystallographically characterized {L = 1,4-bis(2-carbamoylethyl)-7-benzimidazole-2-yl-methyl-1,4,7-triazacyclononane}. It crystallizes in triclinic, space group P1, with a = 13.2425(13), b = 14.0807(15), c = 17.6798(18), α = 86.296(2), β = 72.773(2), γ= 68.905(2)o, V = 2934.5(5) ?~3, Z = 2, D_c = 1.611 g/m~3, F(000) = 1456, M_r = 1423.09, m = 0.920 mm~(-1). The final R = 0.0671 and wR = 0.1874 for 6501 observed reflections with I 2σ(I). The structural analysis shows that the complex cation(CuL]_2~(3+)) was formed by two complex cations, namely(CuL~3]~(2+) and CuL_(-H)~3]~+) through a hydrogen bond. In each complex cation, the Cu(Ⅱ) lies in a distorted square pyramidal geometry. The redox behavior was studied by cyclic voltammetry(CV) in aqueous solution which indicates a reversible one electron redox reaction. The result of UV absorption, ethidium bromide(EB) fluorescence spectra indicated that the complex binds to CT-DNA in an intercalative mode. Superoxide dismutase(SOD) activity of the complex was determined by photoreduction of NBT, and the value of IC_(50) is 5.22 μmol·L~(-1).