Cu2+-cyclam complex functionalised with naphthylmethyl fluorescent signalling subunits as fluorescent chemosensors for sulfate in aqueous environment.

The fluorescent behaviour of the polyazacycloalkane containing naphthyl groups 1,4,8,11-tetrakis(naphthylmethyl)-1,4,8,11-tetraazacyclotetradecane (L1) and its Cu2+ complex in the presence of anions are compared in aqueous environment (THF:water 70:30 v/v, 0.1 mol dm−3 tetrabutylammonium perchlorate, 25°C). The emission fluorescent intensity of the L1–Cu2+ system is selectively enhanced in the presence of sulfate at acid pH.