Synthesis, Characterization And DNA Binding Studies Of Some Novel Complexes

In the paper, synthesis method and applications of benzimidazole complexes on the medicine and drygoods etc are introduced. Experimental methods for studying mechanisms of benzimidazole complexes binding to DNA are reviewed, including UV, Fluorescence, Viscosity measurement and electrochemistry method.2,6-bis(benzimidazy-2')pyridine has been synthesized rapidly by microwave irradiation, The yields are the same as conventional synthesis, and the reaction rate in this condition is 80 times as that in conventional synthesis condition, so the reaction time is greatly reduced. Moreover the optimum synthesized condition under microwave irradiation has been explored. The four complexes of Zinc(Ⅱ), nickel(Ⅱ), cadmium(Ⅱ), chromium(Ⅲ) with 2,6-bis(benzimidazy-2')pyridine were synthesized in the conventional condition, characterized by UV, TG-DSC, infrared spectroscopy and fluorescence spectra, investigated about electrochemical behaviors through cyclic voltammetry and differential pulse voltammetry techniques. The cyclic voltammetry of the complexes have showed all irreversible redox couple. In addition, UV spectra are very sensitive to solution pH, especially the complex of Zinc(Ⅱ). With the increasing of the pH value, the maximum absorption the complex of Zinc(Ⅱ) at 311 nm decreases and appears red shift, then a new shoulder appears at 362 nm for the ligand π-π* transitions, and the absorbance increases. Since the complexe acts as dibasic acids, in which N-H protons on benzimidazole moieties are responsible for a deprotonation site. Both reduction potentials are strongly dependent on the solution pH, which leads to the basis of a proton-induced molecular switch. In inverse, the deprotonation of N-H protons can influence the electric charge distribution, electrochemical behaviors and the spectra property.