Modification of photochemical reactivity by zeolites: location of guests within faujasites by heavy-atom-induced phosphorescence

Heavy-atom-induced phosphorescence of naphthalene included in faujasites has been observed and evidence obtained for the existence of direct interaction between the heavy metal cations present within the zeolite supercage and the included aromatic guest. Naphthalene when included in faujasites exchanged with rubidium and cesium as cations exhibits intense phosphorescence and possesses short singlet and triplet lifetimes. When adsorbed in faujasites exchanged with lithium, sodium and potassium as cations, naphthalene gives intense fluorescence and weak phosphorescence with long singlet and triplet lifetimes