REDOX SWITCHING OF ANTHRACENE FLUORESCENCE THROUGH THE CU-II CU-I COUPLE/

Fluorescence of the anthracene fragment of the supramolecular system 1 is reversibly switched on/off through the Cu-I/Cu-II redox couple ins ide the appended tetrathia ring. The OFF state is generated through a thermodynamically favored electron transfer process from anthracene ex cited state An to Cu-II, which quenches fluorescence. The Cu-I-to-*An electron transfer process is not thermodynamically favored, and fluor escence is revived (ON state). On/off switching of anthracene fluoresc ence can be carried out at will, by consecutively varying the potentia l of the working electrode in a controlled-potential electrolysis expe riment.