Hydroxythiazole‐Based Fluorescent Probes for Fluoride Ion Detection

This work describes the synthesis of five O ‐silyloxy‐1,3‐thiazoles and their use as fast‐response “turn‐on” probes for fluoride ion detection in polar aprotic solvents and in aqueous cetyltrimethylammonium bromide micellar medium. The fluoride‐triggered deprotection of these silyl ethers results in ca. 180‐nm shifts in the fluorescence emission wavelengths. All compounds are suitable for the detection of fluoride ions with a detection limit in DMSO of 10 –7 mol L –1 ; derivatives containing a 2‐pyridyl moiety in the thiazole system are more efficient than those with a 3‐ or 4‐pyridyl moiety. Typical anionic interferents, such as acetate or chloride, are not detected by O ‐silyloxy‐1,3‐thiazoles, making these compounds very specific for fluoride.