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