A near-Infrared Fluorescent Chemodosimeter for Ratiometric Detecting Fluoride Based on Desilylation Reaction.

A new chemodosimeter based on dicyanomethylene-4H-chromene chromophore (probe 1) was developed as a ratiometric fluorescent probe in near-infrared range for F with good selectivity in acetonitrile. Probe 1 could be used to directly visualize F by the naked eye and showed more than 621-fold fluorescence enhancement at 715 nm upon reaction with F upon excitation at 625 nm. The recognition of probe 1 to fluoride was featured by F-induced red-shifts of both absorption (185 nm) and fluorescence peaks (132 nm) based on internal charge transfer (ICT) in acetonitrile. The desilylation reaction of 1 by F was proposed for its dual absorption and emission ratiometric detection of fluoride. [ABSTRACT FROM AUTHOR]