A Metal–Macrocycle Complex as a Fluorescent Sensor for Biological Phosphate Ions in Aqueous Solution

Abstract

AbstractWe synthesized tetraazamacrocycles 1 and 2 bearing two anthryl groups as sidearms, both of which exhibited high selectivity for the ZnII ion in switching‐on‐type responses in aqueous solution. For ligand 1, ZnII is coordinated by four nitrogen atoms of the macrocycle and two amino groups on the pendent arms, which results in proximity between the twofluorophores. So, 1‐ZnII shows obvious excimer emission in aqueous solution. When PPi or ATP was added (pH 7.4), the excimer emission of 1‐ZnII was quenched, whereas monomer emission was revived. To the best of our knowledge, no other known sensor has this characteristic under physiological pH conditions. At the same time, the obvious different fluorescence response of 1‐ZnII for PPi and ATP in water shows that receptor 1‐ZnII can be used as a selective fluorescent chemosensor for PPi and ATP anions.