Department of Advanced Materials Chemistry Graduate School of Engineering Science, Yokohama National University Tokiwadai, Hodogaya, Yokohama, 240-8501, Japan.
Chemphyschem. 2020 Jul 2;21(13):1375-1383. doi: 10.1002/cphc.202000309. Epub 2020 Jun 3.
A chiral and thermally irreversible photochromic fulgide derivative incorporating an (R)-binaphthol unit in its acid anhydride moiety was used for the photoswitching of the pitch length of cholesteric liquid crystals. Since the absorption maximum wavelengths of both thermally stable photoisomers are nearly in the UV region (quasi-stealth photochromism), it can be exposed to visible light without inducing photochromic reactions. Therefore, when the photoswitching molecule is added to a permanent cholesteric liquid crystal whose reflection light wavelength is in the visible region, the UV light-induced photochromic reaction of the photoswitching molecule changes the wavelength of the reflection light in the visible light region. We have succeeded in regulating the color of cholesteric liquid crystalline cells between red and blue upon UV light irradiation. Attempts to introduce this system in polymer dispersed cholesteric liquid crystals are also described.
一种手性和热不可逆的俘精酸酐衍生物，其酸酐部分含有（R）-联萘酚单元，用于胆甾相液晶的螺距长度的光致切换。由于两种热稳定的光异构体的吸收最大值波长都在紫外区（准隐形光致变色），因此可以在不引起光致变色反应的情况下暴露在可见光下。因此，当将光致变色分子添加到其反射光波长在可见光区的永久性胆甾相液晶中时，光致变色分子的紫外光诱导光致变色反应会改变可见光区反射光的波长。我们已经成功地在紫外光照射下将胆甾相液晶盒的颜色调节为红色和蓝色之间。还描述了将该系统引入聚合物分散胆甾相液晶中的尝试。
