The V-shaped ligand bis(N-allylbenzimidazol-2-ylmethyl)benzylamine and its Ag(I) complex: Synthesis, crystal structure, DNA-binding properties and antioxidation

A novel dinuclear Ag(I) complex of the type, [Ag2L2](pic)2, was synthesized by the reaction of the V-shaped ligand bis(N-allylbenzimidazol-2-ylmethyl)benzylamine (L) with Ag(pic) (pic = picrate). Ligand L and Ag(I) complex were characterized on the basis of elemental analysis, UV–vis, IR, NMR spectroscopy and X-ray crystallography. Single-crystal X-ray revealed that two L coordinated to a central silver(I) cation in a near-linear fashion through their benzimidazol-1-yl nitrogen atoms, and a centrosymmetric dinuclear pore canal structure was constructed in the discrete [Ag2L22]2+ cation. The DNA-binding properties of the free ligand L and Ag(I) complex have been carried out by using electronic absorption, fluorescence, and viscosity measurements. The results support that ligand L and Ag(I) complex both bind to DNA via an intercalative binding mode, and the affinity for DNA is more strongly in case of Ag(I) complex when compared with ligand L. Moreover, Ag(I) complex also exhibited potential antioxidant properties in vitro studies.