Synthesis and Fluoride Detection Properties of a Coumarin Derivative

Abstract A new and simple colorimetric receptor 1 was prepared easily by one-step condensation of 3-acetyl-4-hydroxycoumarin and 8-aminoquinoline. Its absorbance at λ 296 nm significantly increased upon addition of Fe3+ with a turn-on mode. Furthermore, turn-off sensing happened when F– was added to the 1–Fe3+ complex formed in situ. The 1–Fe3+ complex showed high selectivity and low detection limit toward F– ion. Free Schiff base 1 was then given off for recognition Fe3+ again. The reversible “off-on-off” sensing occurred upon sequential addition of Fe3+ and F–.