Synthesis, characterization, and DNA-binding of enantiomers of iron(II) Schiff base complexes
作者:Zhi-Guo Gu、Jing-Jing Na、Fei-Fei Bao、Xin-Xin Xu、Wen Zhou、Chun-Yan Pang、Zaijun Li
DOI:10.1016/j.poly.2012.12.027
日期:2013.3
Two pairs of iron(II) chiral enantiomers fac-Delta-[Fe(S-L1)(3)][ClO4](2) and fac-Lambda-[Fe(R-L1)(3)][ClO4](2) (Delta-1 and Lambda-1), fac-Delta-[Fe(S-L2)(3)][ClO4](2) and fac-Lambda-[Fe(R-L2)(3)][ClO4](2) (Delta-2 and Lambda-2), L1 = (R/S)-(+/-)-1-naphthyl-N-(pyridine-2-ylmethylene)ethanamine, L2 = (R/S)-(+/-)-2-naphthyl-N-(pyridine-2-ylmethylene)ethanamine were synthesized and characterized by elemental analysis, IR, UV-Vis, CD and H-1 NMR spectra. The X-ray structural analyses of Lambda-1 and Delta-2 revealed that the iron(II) complexes possess octahedral coordination geometry for N6 donor atoms by three bidentate ligands. R-L1 ligand induces the fac-Lambda isomer, while S-L2 ligand induces the fac-Delta isomer. The enantioselective binding of iron(II) chiral enantiomers to calf-thymus DNA (ct-DNA) has been investigated by methods of UV-Vis, fluorescence, and circular dichroism spectrometry. All the complexes could bind to ct-DNA and showed different binding affinities with the binding constants ranging from 0.91 x 10(5) to 1.43 x 10(5) M-1. Moreover, the Delta enantiomers exhibited more efficient DNA interaction with respect to the A enantiomers. (C) 2013 Elsevier Ltd. All rights reserved.