Synthesis, crystal structures, antioxidant activities and DNA-binding studies of two manganese(II) complexes with 1,3-bis(1-ethylbenzimidazol-2-yl)-2-oxopropane ligands

Research paper by Huilu Wu, Furong Shi, Xiaoli Wang, Yanhui Zhang, Yuchen Bai, Jin Kong, Cuiping Wang

Indexed on: 30 Jan '14Published on: 30 Jan '14Published in: Transition Metal Chemistry


Two manganese(II) complexes, [Mn(Etobb)2](pic)2·2DMF (pic = picrate) 1 and Mn(Etobb)Cl22, where Etobb is 1,3-bis(1-ethylbenzimidazol-2-yl)-2-oxopropane, were synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structures of both complexes have been determined by X-ray single crystal diffraction. The coordination environment of the Mn(II) atom in complex 1 can be described as distorted, while complex 2 has as a distorted square-pyramidal geometry. For both complexes, π–π stacking interactions link the structures into 1D infinite networks. The interactions of free Etobb and its complexes with calf thymus DNA were investigated by using electronic absorption titration, ethidium bromide-DNA displacement experiments and viscosity measurements. Furthermore, the antioxidant activities of the complexes were determined by superoxide and hydroxyl radical scavenging methods in vitro; both complexes are able to suppress O2−·and HO·, and complex 1 is more effective than complex 2.