Synthesis of thionaphthalimides and their dual Hg2+-selective signaling by desulfurization of thioimides

Abstract

A series of new thionaphthalimide derivatives were prepared, and their Hg2+-selective signaling behavior was investigated in aqueous acetonitrile solution. A monothionaphthalimide (anti) exhibited pronounced Hg2+-selective chromogenic signaling behavior through a solution color change from red to yellow, which was easily detectable by eye. It (anti) also showed prominent off-on type Hg2+-selective fluorescent signaling behavior. The signaling is due to the Hg2+-assisted desulfurization of the thioimide to its imide structure. The presence of other common metal ions did not interfere with the Hg2+-signaling of the monothionaphthalimide (anti). The detection limit of monothionaphthalimide (anti) for the determination of Hg2+ ions in 30% aqueous acetonitrile was estimated to be 2.7 mu M. (C) 2012 Elsevier Ltd. All rights reserved.