Highly Selective Fluorescent Probe Based on 2-(2′-Dansylamidophenyl)-Thiazole for Sequential Sensing of Copper(II) and Iodide Ions

A novel highly selective fluorescent probe based on 2-(2′-dansylamidophenyl)-4-phenylthiazole (1) is developed for sequential sensing of copper(II) and iodide ions in acetonitrile. The fluorescence mechanism is based on cation-induced inhibition of excited-state intramolecular hydrogen transfer, intramolecular charge transfer, and metal–ligand electron/charge transfer. Subsequent iodide-induced extrusion of copper(II) results in partial revival of fluorescence. Probe 1 and its ensemble with copper (II) show high selectivity for copper(II) and iodide ions, respectively, in acetonitrile solution.