Cu2+- and Hg2+-Selective Chemosensing by Dioxocyclams Having Two Appended Pyrenylacetamides

Abstract

Two new chemosensors 1 and 2 derived from 5,12- and 5,7-dioxocyclams were prepared and their signaling behaviors toward transition metal ions were investigated. Chemosensors 1 and 2 showed very efficient responses toward Cu2+ and Hg2+ ions. Ratiometric analysis of the fluorescence changes in pyrene monomer and excimer emissions clearly demonstrated the Cu2+- and Hg2+-selective signaling behavior. The signaling mechanism of the chemosensors is due to conformation changes upon complexation with metal ions and the inherent quenching nature of the complexed Cu2+ and Hg2+ ions themselves.