A selective 'turn-on' fluorescent sensor for Hg~(2+) based on 'reactive' 7-hydroxycoumarin compound

摘要

A simple 7-hydroxycoumarin-based compound LI was rationally designed and synthesized behaving as a highly selective fluorescent sensor for Hg~(2+) in aqueous media. It shows selective and "turn-on" fluorescence upon addition of Hg~(2+). Fluorescence titration and 'H NMR investigation reveal that the fluorescence enhancement of LI upon Hg~(2+) addition is promoted by Hg~(2+)-induced cyclization of LI to a more rigid dihydrobenzofuran derivative.