Terphenyl based fluorescent chemosensor for Cu 2+ and F − ions employing excited state intramolecular proton transfer

Abstract

A new terphenyl based bifunctional fluorescent chemosensor 3a has been synthesized, which demonstrates selective optical recognition of Cu 2+ and F − ions in two contrasting modes. The compound shows highly selective ‘On–Off’ switchable behavior toward Cu 2+ ions and ‘On–Off–On’ behavior toward F − ions among various cations and anions tested. The detection limits of chemosensor for Cu 2+ and F − ions are found to be 100 nM and 10 nM, respectively.