Uchida Emi, Sakaki Kouji, Nakamura Yumiko, Azumi Reiko, Hirai Yuki, Akiyama Haruhisa, Yoshida Masaru, Norikane Yasuo
Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan).
Chemistry. 2013 Dec 16;19(51):17391-7. doi: 10.1002/chem.201302674. Epub 2013 Nov 8.
Photoinduced phase transitions caused by photochromic reactions bring about a change in the state of matter at constant temperature. Herein, we report the photoinduced phase transitions of crystals of a photoresponsive macrocyclic compound bearing two azobenzene groups (1) at room temperature on irradiation with UV (365 nm) and visible (436 nm) light. The trans/trans isomer undergoes photoinduced phase transitions (crystal-isotropic phase-crystal) on UV light irradiation. The photochemically generated crystal exhibited reversible phase transitions between the crystal and the mesophase on UV and visible light irradiation. The molecular order of the randomly oriented crystals could be increased by irradiating with linearly polarized visible light, and the value of the order parameter was determined to be -0.84. Heating enhances the thermal cis-to-trans isomerization and subsequent cooling returned crystals of the trans/trans isomer.
由光致变色反应引起的光诱导相变会在恒定温度下导致物质状态的变化。在此，我们报道了一种带有两个偶氮苯基团的光响应大环化合物（1）的晶体在室温下用紫外光（365 nm）和可见光（436 nm）照射时的光诱导相变。反式/反式异构体在紫外光照射下发生光诱导相变（晶体-各向同性相-晶体）。光化学产生的晶体在紫外光和可见光照射下在晶体和中间相之间表现出可逆的相变。通过用线偏振可见光照射，可以增加随机取向晶体的分子有序度，并且有序参数的值被确定为-0.84。加热会增强热顺反异构化作用，随后冷却会使反式/反式异构体的晶体恢复。
