Bisbinaphthyl Macrocycle-Based Highly Enantioselective Fluorescent Sensors for α-Hydroxycarboxylic Acids

Bisbinaphthyl-based macrocycles are found to carry out highly enantioselective fluorescent recognition of α-hydroxycarboxylic acids. It is observed that within a certain concentration range, one enantiomer of the chiral acids can increase the fluorescence intensity of the macrocycles by 2−3-fold, while the other enantiomer scarcely enhances the fluorescence. Such unusually high enantioselective responses make these macrocycles very attractive as fluorescent sensors in determining the enantiomeric composition of α-hydroxycarboxylic acids.