Thermally Reversible Photochromic Systems.Photochromism of a Dipyrrolylperfluorocyclopentene
A diarylethene having 2-cyanopyrrole rings turned blue upon UV irradiation in ethyl acetate. The colored form was unstable and returned to the colorless open-ring form with a half-life time of 37 s at room temperature. The activation energy of the thermal fading was obtained to be 32.5 kJ / mol, which is less than half of that of spironaphthoxazine.
- Chemistry letters
Chemistry letters 1999(8), 835-836, 1999-08-05
The Chemical Society of Japan