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-triazacyclononane[CuL](2)(PF6)(3)- MeCN center dot H2O 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 P (1) over bar, with a = 13.2425(13), b = 14.0807(15), c = 17.6798(18), alpha = 86.296(2), beta = 72.773(2), gamma = 68.905(2)degrees, V = 2934.5(5) angstrom(3), Z = 2, D-c = 1.611 g/m(3), F(000) = 1456, M-r = 1423.09, mu = 0.920 mm(-1). The final R = 0.0671 and wR = 0.1874 for 6501 observed reflections with I > 2 sigma(I). The structural analysis shows that the complex cation ([CuL](2)(3+)) was formed by two complex cations, namely ([CuL3](2+) and [CuL-H3](+)) 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 IC50 is 5.22 mu mol.L-1.