[EN] DIARYLETHENE COMPOUND, TEMPERATURE INDICATOR, TEMPERATURE DISPLAY DEVICE, AND PACKAGE<br/>[FR] COMPOSÉ DE DIARYLÉTHÈNE, INDICATEUR DE TEMPÉRATURE, DISPOSITIF D'AFFICHAGE DE TEMPÉRATURE ET BOÎTIER<br/>[JA] ジアリールエテン化合物、温度インジケータ、温度表示デバイス及び包装体
Photochromism of 1,2-Bis(2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene in a Single-Crystalline Phase. Conrotatory Thermal Cycloreversion of the Closed-Ring Isomer
1,2-Bis(2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene (1a) was found to undergo a thermally reversible photochromic reaction in solution as well as in the single-crystalline phase. Upon irradiation with ultraviolet light the hexane or toluene solution containing 1a and single-crystal 1a turned blue along with the formation of closed-ring isomer (1b). The blue solution and single crystal returned