The location of organic guests within X-type faujasite zeolites via external heavy-atom induced phosphorescence

Abstract

Heavy-atom induced phosphorescence of naphthalene and related aromatic guest molecules included in X-type faujasite zeolites (M⁺X^-, M⁺ = Li,⁺ Na,⁺ K⁺, Rb⁺, Cs⁺, Tl⁺)_has been studied and evidence has been obtained for direct interactions between the heavy-atom cations present within the zeolite supercage and the included organic guest. As expected for an external heavy-atom perturbed excited state, both singlet and triplet excited state lifetimes and emission efficiencies depend upon the identity and accessibility of the cation. The use of photophysical probes to monitor the guest's local environment and approaches to monitoring guest diffusion processes within zeolites via. phosphorescence are discussed.