Hirose Takashi, Matsuda Kenji, Irie Masahiro
Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, Japan.
J Org Chem. 2006 Sep 29;71(20):7499-508. doi: 10.1021/jo060505t.
Diarylethene derivatives with hexaethylene glycol side chains were synthesized and their self-assembling and photochromic reactivity were investigated. The diarylethenes showed photochromism in organic solvents and even in water. The aqueous solution of the compounds turned turbid quickly upon heating. The clouding behavior was investigated using 1H NMR spectroscopy, dynamic light scattering, and absorption spectroscopy. It was revealed that, in the aqueous solution, the compounds self-assembled into aggregates, and the aggregates were loosened by raising the temperature. The cloud-point temperature of the closed-ring isomer was 5-7 degrees C lower than that of the open-ring isomer. When asymmetric methyl groups were introduced in the amphiphilic side chains, induced circular dichroism (ICD) was observed upon irradiation with UV light in water. This ICD was explained by the difference in the self-assembling behavior between the open- and the closed-ring isomers. It was suggested that the closed-ring isomers assembled into a chiral nanostructure.
合成了带有六甘醇侧链的二芳基乙烯衍生物，并研究了它们的自组装和光致变色反应活性。这些二芳基乙烯在有机溶剂甚至水中都表现出光致变色现象。化合物的水溶液加热后迅速变浑浊。使用核磁共振氢谱、动态光散射和吸收光谱对这种浑浊行为进行了研究。结果表明，在水溶液中，这些化合物自组装成聚集体，并且通过升高温度聚集体会变得松散。闭环异构体的浊点温度比开环异构体低5 - 7摄氏度。当在两亲性侧链中引入不对称甲基时，在水中用紫外光照射会观察到诱导圆二色性（ICD）。这种ICD可以通过开环和闭环异构体之间自组装行为的差异来解释。有人认为闭环异构体组装成了手性纳米结构。
