The synthesis, photophysical properties and fluoride anion recognition of a novel branched organoboron compound

A novel two-branched organoboron compound, N,N-bis(7-dimesitylboryl-9,9-diethyl-9H-fluorene-2-yl)aniline, containing a phenylamino group as a π-electron donor, fluorene groups as π-bridges and dimesitylboryl groups as electron acceptors, was synthesized and its photophysical properties in various solvents as well as its fluoride anion recognition properties were investigated. The synthesised compound exhibited strong fluorescence in all solvents with the fluorescence changing from blue to orange on going from solvents of low polarity to those of high polarity. The compound was able to recognize fluoride anions in high sensitivity owing to strong interactions between boron atoms and fluoride anions.