Highly efficient fluorescent BODIPY dyes for reaction-based sensing of fluoride ions

A series of red-emitting boron-dipyrromethene dyes (BODIPY) for reaction-based sensing of fluoride ion have been prepared by functionalization of the methyl groups located in the 3,5 substitution positions of BODIPY dyes. These highly colored dyes display absorption and emission wavelengths in the range of 585-670 nm and 614-687 nm, respectively. The presence of trihexylsilyl (THS) and trimethylsilyl (TMS) make them sensitive to fluoride ions, which induces strongly large blue-shift (70-117 nm) and significant increase (6-40 fold) of the fluorescence intensity in the emission spectra. Their optical properties, response time and limit of detection depend on the styryl substituents. To the best of our knowledge, one of the red-emitting probes exhibits the largest blue-shift ever observed of the fluorescence band when subjected to F- (117 nm), along with a 40-fold enhancement of fluorescence intensity. (C) 2015 Elsevier B.V. All rights reserved.