Fluoride anion detection based on the excited state intramolecular proton transfer (ESIPT) of 2-(o-hydroxyphenyl)imidazole induced by the Si-O cleavage of its silyl ether

Two fluorescent chemo-sensors (SiOPI and SiOPIC) with masked excited-state intramolecular proton transfer (ESIPT) were synthesized and characterized. In the presence of fluoride anion, the masked ESIPT was activated by the cleavage of Si-O bond. These sensors are remarkable in regard to its high selectivity, high sensitivity, and fast response to fluoride anion, while not being affected by the presence of hydroxide anion.