Synthesis, structure, and DNA-binding properties of manganese(II) and nickel(II) complexes with tris(N-ethylbenzimidazol-2-ylmethyl)amine ligand

Abstract

Tris(N-ethylbenzimidazol-2-ylmethyl)amine (Etntb), [Mn(Etntb)(DMF)(H₂O)](pic)₂ (1), and [Ni(Etntb)(DMF)(H₂O)](pic)₂ (2) (pic = picrate) have been synthesized and characterized by elemental analyses, molar conductivities, UV–Visible spectra, and IR spectra. Single-crystal X-ray diffraction revealed that the complexes have the same arrangement with distorted octahedral coordination geometries. DNA-binding properties of the free ligand, 1, and 2 have been investigated by electronic absorption, fluorescence, and viscosity measurements. The results suggest that the ligand and its complexes bind DNA via intercalation, and their binding affinity for DNA follows the order 2 > 1 > ligand.

Graphical Abstract

Keywords:

• Tris(N-ethylbenzimidazol-2-ylmethyl)amine
• Mn(II) and Ni(II) complexes
• Crystal structure
• DNA binding

Funding

The present research was supported by the National Natural Science Foundation of China [grant number 21367017]; the Fundamental Research Funds for the Gansu Province Universities [grant number 212086]; National Natural Science Foundation of Gansu Province [grant number 1212RJZA037]; and “Qing Lan” Talent Engineering Funds for Lanzhou Jiaotong University.