Fluorescent chemosensors of carbohydrate triols exhibiting TICT emissions

4-4'-Disubstituted biphenyl boronic acids (BBAs) are push-pull fluorophores with turn-on'' fluorescence properties. Upon carbohydrate triol binding, BBA boronate esters can participate in photon-induced electron transfer, giving a twisted intramolecular charge transfer (TICT) complex. The resulting TICT emissions distinguish between carbohydrates that bind to boron as a diol versus triol unit, thereby revealing stereochemical information about the carbohydrate.