Synthesis, Crystal Structure and DNA-Binding Study of a New Zinc(II) Complex Based on 2,6-Bis(imino)pyridyl Ligand

Abstract

A new zinc complex [Zn(L1)Cl2]2‧CH3OH‧2H2O (complex 1), where L1 stands for 2,6-Bis{[(4-ethylphenyl)imino]ethyl}pyridine (L1) has been synthesized and characterized. The crystal structure of L1 and complex 1 have been determined by single-crystal X-ray diffraction. Both compounds crystallize in the monoclinic P21/c space group. For the ligand L1, the crystal parameters are a = 16.7487(7) A, b = 5.8177(3) A, c = 21.8427(10) A, β = 104.1350(10)° and Z = 4. For complex 1, the crystal parameters are a = 8.0216(14) A, b = 13.433(2) A, c = 24.640(4) A, β = 90.223(3)° and Z = 2. In the crystal structure of complex 1, L1 acts as a tridentate ligand and coordinated with Zn1 with three nitrogen atoms. Together with two chlorine atoms, Zn1 atom is five-coordinated in a trigonal bipyramidal geometry. Hydrogen bonds play great role in the crystal structure of complex 1 and form a two-dimensional network. Furthermore, the DNA-binding property of complex 1 with fish sperm DNA (FS-DNA) has been investigated by electronic absorption titration. The result suggests that complex 1 might interact with FS-DNA via groove binding mode. The single crystals of 2,6-Bis{[(4-ethylphenyl)imino]ethyl}pyridine (L1) and it’s Zinc(II) complex [Zn(L1)Cl2]‧CH3OH‧H2O (1) were determined. In the crystal structure of complex 1, Zn1 atom is five-coordinated in a trigonal bipyramidal geometry. A two-dimensional network is formed by hydrogen bonds. DNA-binding study indicated that complex 1 interact with FS-DNA via groove binding mode.