Reaction-Based Sensing of Fluoride Ions Using Built-in Triggers for Intramolecular Charge Transfer and Photoinduced Electron Transfer

Two Bodipy derivatives with silyl-protected phenolic functionalities signal fluoride concentrations both in solution and in a poly(methyl methacrylate) matrix. The exact location of the nascent phenolate group Is Important. If it is at the meso position, photoinduced electron transfer is triggered; however, if it is in full conjugation via a styryl moiety to the Bodipy core, strong Intramolecular charge transfer is triggered, resulting in a large red shift in the absorbance peak. In either case, a selective methodology for fluoride sensing is the invariable result.