Synthesis, crystal structure and nuclease activity of a new Mn(II) complex involving 2-(2-1H-imidazolyl)-1H-imdazolium ligand

A new Mn(II) complex of Mn(H3biim)2(NCS)2Cl2 (H3biimdouble bond; length as m-dash2-(2-1H-imidazolyl)-1H-imidazolium) was synthesized and characterized by elemental analyses and X-ray single crystal diffraction. In the X-ray crystallography structure, the Manganese (II) ion is coordinated by two nitrogen atoms of two 2-(2-1H-imidazolyl)-1H-imdazolium, two nitrogen atoms of two thiocyanate ions and two Cl−. The interaction of the complex with calf thymus DNA was investigated through fluorescence spectroscopy and viscosity measurement. These results show that the Mn(II) complex can electrostatically bind to the phosphate group of DNA backbone. Furthermore, the complex is able to promote pBR322 DNA cleavage at pH = 7.2 and 37 °C. The hydrolytic cleavage of DNA by the complex was supported by the evidence from free radical quenching, anaerobic experiment.