BODIPY-based fluorescent sensors with tunable binding ability to fluoride and hydrogen sulfate anions

Abstract

The binding and sensing abilities of BODIPY based fluorescent sensors 1 and 2 towards various anions have been studied by absorption, emission and ¹H NMR titrations spectroscopy. Sensor 1 shows selective response toward fluoride anions through hydrogen bonding interaction, while sensor 2 acts as a highly selective ‘‘Off–On’’ fluorescent sensor for hydrogen sulfate anion in DMSO solvent. The fluorescence response of sensor 2 towards HSO₄^- may be due to the suppressed PET (photo-induced electron transfer) process induced by the multiple hydrogen bonding interactions between sensor 2 and HSO₄^-.