Action of a fluorescent chemosensor for Cu2+ encapsulated in silica xerogel

The fluorescent chemosensor of the type Ant-NH-O-O-NH-Ant for Cu2+ ions has been designed by means of a supramolecular approach, as follows: two anthr acene (Ant) fragments as fluorophore subunits have been linked by a noncycl ic NH-O-O-NH quadridentate ligand as a receptor. The interaction of Cu2+ - receptor is signalled through the enhancement of the anthracene fluorescenc e when the receptor, i.e., the dioxodiamine chain subunit of the sensor is able to stop a photoinduced electron-transfer mechanism. The experiments wi th the chemosensor encapsulated in silica xerogel by the sol-gel processing are described.