Molecular composites that possess unique emission properties have been prepared by introducing luminescent molecules into sol-gel based silica glasses. The lumophores chosen for study are terbium(III) and europium(III) ions whose emissions are quenched in aqueous and sol-gel environments owing to coordination of water molecules to the lanthanide ion. To overcome the quenching process the ions have been encapsulated within cryptands. The resulting terbium(IU) and europium(III) cryptates possess long-lived excited states in both aqueous solution and solgel glassy matrices. Measurements of the excited state dynamics of these molecularly engineered composites demonstrate the feasibility of tailoring molecules to retain their excited state properties in sol-gel derived glasses.
