On the luminescence of luminol in DMSO in the presence of potassium superoxide-18-crown-6-ether and fluorescein

Luminol solution in DMSO in the presence of [18C6…K]+ O2radical dot− supramolecular complex (achieved from KO2 and 18-Crown-6 (18C6)-ether) is chemiluminescent, and its intensity depends on the complex concentration. Using fluorescein (Fl) as an energy acceptor in this system, the luminescence energy transfer process from chemically excited species, aminophtalate dianion, to Fl could be evidenced. On the basis of Förster theory, the critical energy transfer distance, for both fluorescence and chemiluminescence, has been determined. The values are comparable: 22.41 Å (for chemiluminescence) and 20.88 Å (for fluorescence).