Photochromism of Diarylethenes on Porous Aluminum Oxide: Fatigue Resistance and Redox Potentials of the Photochromes

The photochromism of three diarylethene derivatives was examined on porous aluminum oxide. Upon alternate irradiation with UV and visible light, the diarylethenes having thiophene rings decomposed easily, while a derivative having benzothiophene rings underwent a reversible photochromic reaction. The decomposition started from the closed-ring isomers of the dithienylethenes. The decomposition mechanism was discussed based on the oxidation potentials of the compounds.