Photochromic nafion films containing cationic diarylethenes

Abstract Transparent photochromic films were conveniently prepared by incorporating two different cationic diarylethenes into an ion-exchange Nafion film. The colorless films changed to dark blue or violet upon UV light irradiation, and subsequently switched to colorless under visible light. The films exhibited high photochromic durability compared with that in solution. The diarylethene molecules were also significantly more stable to photochromic reaction in the Nafion film than in the solution state.