1,10-邻菲啰啉并咪唑衍生物阴离子受体的合成及识别性能

Abstract

Anion play important roles in a wide range of chemical, biological and environmental processes. So anion binding and sensing became an active research field in supramolecular chemistry with potential applications in biomedical and environmental monitoring, anion exchange as well as anion transport. Artificial neutral receptors for anions are designed and synthesized in which color metric sensors are paid a good deal of attention for they could efficiently change their photo physical properties in the presence of anions. Imidazole and phenol are recently used in the design of neutral receptors for anions due to their ability to act as H-bond donors. Two anion receptors of 1H-imidazo[4,5-f][1,10]phenanthroline derivatives,2-(2-hydroxyphenyl)-1H-imidazo[4,5-f][1,10]phenan-throline (1) and 2-(2-hydroxy-5-bromophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (2) were designed and synthesized, and the structure of compound 2 was confirmed by single crystal X-ray diffraction analysis. Anion sensing and the mechanism studies were carried out by UV-Vis spectrophotometric titration and 1H NMR titration. The receptors exhibited sensing towards CH3COO(superscript -),F(superscript -)and H2PO4(superscript -) with color of the solution changed from pale yellow to yellow, and weakly sensing towards Cl(superscript -)with inconspicuous response towards Br(superscript -)and I(superscript -) in DMSO. The receptors formed hydrogen bond supramolecular with anions F(superscript -),H2PO4(superscript -) and CH3COO(superscript -) as 1∶1 within[receptor]/=1. As flowed with the molar ratio exceeded 1, the proton of 1H-imidazo deprotoned and linked with the anion. The receptors formed hydrogen bond supramolecular with Cl(superscript -).