Syntheses, Crystal Structures and DNA-binding Properties of Cd(II), Co(II), Cu(II) and Zn(II) Complexes Containing Imidazolium Derivatives

Cd(II), Co(II), Cu(II) and Zn(II) complexes (1 similar to 4) based on 2-(2-pyridyl)benzimidazole (pbm) and 4,4'-oxybisbenzoic acid (H(2)odc) were synthesized. The formulas of these complexes are [Cd(pbm)(odc)(2)](1), [Co(pbm)(odc) 2 1 (2), [Cu(pbm)(odc)(2)](3) and [Zn(pbm)(odc)(2)](4) confirmed by single-crystal X-ray diffraction analysis, which shows that complexes 1, 2 and 4 belong to monoclinic system with space group P2(1)/n, while complex 3 belongs to monoclinic system with space group P2(1)/c. The binding properties of complexes 1 similar to 4 with CT-DNA are evaluated by ultraviolet spectrum, fluorescence spectra and viscosity measurements. The results indicate that complexes 1 similar to 4 have strong interaction with CT-DNA binding. These complexes exhibit an electrostatic or groove mode in respect of binding with DNA, which can effectively destroy DNA. And this binding mode may be applied to the interaction between the complexes and cancer cell DNA. Therefore, we hope to provide a theoretical and scientific basis for the research of anti-cancer drugs.