A highly selective naked-eye and fluorescent probe for fluoride ion based on 1,8-naphalimide and benzothizazole

Based on benzothizazole and 1,8-naphalimide, a novel colorimetric and fluorescent probe (probe 1) for fluoride ion was synthesized by Schiff base reaction. The striking yellow-to-blue color change of the probe 1 in the CH3CN was observed with the naked eyes only in presence of F- among the eight anions (F-, Cl-, Br-, I-, NO3-, HSO4- H2PO4-, AcO-). Besides that, upon addition of F-, both of the absorption and emission peaks shifted to near-infrared region (NIR) (>600 nm) in UV-vis and fluorescent spectra, and the detection limit reached as low as 0.41 mu M. Furthermore, the H-1 NMR titration and theoretical calculation based on TD-DFT indicated that the fluoride ion induced deprotonation of the probe 1 through hydrogen bonding interaction between amino group of probe 1 and fluoride ion. (C) 2017 Elsevier Ltd. All rights reserved.