Fluorescent Anion Receptor with Two Methylene Bridged Bis-imidazolium Ring on Anthracene

摘要

Artificial receptors for selective anion recognition is an area of intensive investigation as anions play a fundamental role in a wide range of chemical and biological process.Receptors based on guest anion induced changes of color or fluorescence seems to be attractive due to their high sensitivity and low detection limit.In many cases,hydrogen bonds are utilized as anion recognition element as host-guest complementarity could be achieved from the directionality of hydrogen bonds.The orientation of hydrogen bonds can differentiate anionic guests with different geometries.While most of hydrogen bond anion receptors utilize N-H...X~- or O-H...X~- hydrogen bonds,1,3-disubstituted imidazolium groups are recently introduced as new anion binding hydrogen bond moiety by forming (C-H)~+...X~- hydrogen bonds between C(2)-H in imidazolium rings and the guest anion.Depending on the spatial arrangement of 1,3-disubstituted imidazolium groups,halide,dihydrogen phosphate,dicarbox-ylate,sulfate selective receptors have been reported.