Excellent BODIPY dye containing dimesitylboryl groups as PeT-based fluorescent probes for fluoride

A highly selective fluorescent probe BBDPB for F^- was realized on the basis of the boron-dipyrromethene (BODIPY) dye containing two dimesitylboryl (Mes₂B) moieties. The fluorophore displays highly efficient orange-red fluorescence with an emission peak of 602 nm and quantum efficiency (φ) of 0.65 in dichloromethane solution. Signaling changes were observed through UV/vis absorption and photoluminescence spectra. Obvious spectral changes in absorption and fluorescent emission bands were detected after adding F^- in company with an obvious solution color change from pink to deep blue. The effects of F^- on the electronic structure of BBDPB were studied in detail by performing theoretical calculations using the Gaussian 03 package. According to the theoretical calculation and contrast experiments, the binding of Mes₂B moieties with F^- would give rise to nonradiative photoinduced-electron-transfer (PeT) deactivation from Mes₂B moieties to BODIPY core and then quench the fluorescence. To implement this approach, an excellent solid-film sensing device was designed by doping BBDPB in polymethylmethacrylate (PMMA).