Bisbinaphthyl macrocycle-based highly enantioselective fluorescent sensors for alpha-hydroxycarboxylic acids.

[structure: see text] Bisbinaphthyl-based macrocycles are found to carry out highly enantioselective fluorescent recognition of alpha-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 alpha-hydroxycarboxylic acids.