A Photochromic Dithienylethene That Turns Yellow by UV Irradiation

Abstract 1,2-Bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene which shows a reversible color change from colorless to yellow by UV irradiation was synthesized. The color of the photogenerated closed-ring forms was dependent on the substitution position of the thiophene rings to the perfluorocyclopentene moiety.