New fluorescent chemosensors for cationic guests: 1,8-Bis(azacrown)anthracenes

Abstract

New macrocyclic ditopic anthracenyl receptors display large chelation-enhanced fluorescence (CHEF) effects upon the addition of linear dications +NH 3(CH 2) nNH 3 +. The amplitude of the effect, which is dependent on the chain length, was at a maximum for propylenediammonium cation. This 1,8-bisazacrown anthracene displays different binding affinities toward metal ions compared to those of 9-azacrown anthracene.