A six-coordinate picrate cadmium(II) complex with a new V-shaped ligand 1,3-bis(1-ethylbenzimidazol-2-yl)-2-thiapropane: synthesis, crystal structure, and DNA-binding properties

Abstract

A V-shaped ligand 1,3-bis(1-ethylbenzimidazol-2-yl)-2-thiapropane (L) and its picrate cadmium(II) complex have been synthesized and characterized systematically. In [Cd(L)₂](pic)_2, the Cd(II) is six-coordinate with N₄S₂ donors of two ligands, forming a slightly distorted octahedron. DNA binding properties were investigated by electronic absorption spectroscopy, fluorescence spectroscopy, and viscosity measurements. The compounds bind to DNA via intercalation and the order of binding affinity is ligand>complex.

Keywords:

• 1,3-Bis(1-ethylbenzimidazol-2-yl)-2-thiapropane
• Cadmium(II) complex
• Crystal structure
• DNA binding property
• Intercalation mode

Acknowledgments

We are grateful for the financial support and grant from “Qing Lan” Talent Engineering Funds and Student's Science and Technology Innovation Funds (grant no. DXS2008-041) by the Lanzhou Jiaotong University. The grant from the “Long Yuan Qing Nian” of Gansu Provinces is also acknowledged.