Multistate Photochromism of 1-Phenylnaphthalene-Bridged Imidazole Dimer That Has Three Colorless Isomers and Two Colored Isomers
Multistate Photochromism of 1-Phenylnaphthalene-Bridged Imidazole Dimer That Has Three Colorless Isomers and Two Colored Isomers
复制标题
具有三种无色异构体和两种有色异构体的 1-苯基萘桥咪唑二聚体的多态光致变色
DOI：
10.1021/jp411190d
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Jiro Abe
中科院分区：
文献类型：
--
作者：
Tetsuo Yamaguchi;Sayaka Hatano;Jiro Abe
合成了一种新型的含1-苯基萘的桥联咪唑二聚体，并对其光化学和热化学性质进行了研究.该分子显示出独特的多态光致变色性，其中稳定的无色1，2 ′-异构体A和B通过短寿命双自由基光化学异构化为无色2，2 ′-异构体，在25 °C下半衰期为180 ns。2，2 ′-异构体在高温下通过有色异构体热还原为1，2 ′-异构体A和B。分离出1，2 ′-异构体A和B、2，2 ′-异构体和有色异构体，并通过X-射线晶体学分析确定了它们的分子结构。这些异构体在室温下是稳定的，并且可以通过光照射几乎完全转化为2，2 ′-异构体。本研究为设计一种新型的负性光致变色分子提供了有用的策略，该分子可通过可见光照射来改变分子的性质。
A new type of the bridged imidazole dimer with a 1-phenylnaphthalene moiety that bridges two diphenylimidazole units at the 2- and 2′-positions was synthesized and the photochemical and thermochemical properties were investigated. This molecule shows unique multistate photochromism, in which the stable colorless 1,2′-isomers A and B photochemically isomerize to the colorless 2,2′-isomer through the short-lived biradical with a half-life of 180 ns at 25 °C. The 2,2′-isomer thermally returns to the 1,2′-isomers A and B through the colored isomer at elevated temperatures. The 1,2′-isomers A and B, the 2,2′-isomer, and the colored isomer were isolated, and their molecular structures were determined by X-ray crystallographic analysis. These isomers are stable at room temperature and can be almost fully converted to the 2,2′-isomer by light irradiation. This study serves the useful strategy for the molecular design of a new type of negative photochromic molecules applicable to switch molecular properties by visible light irradiation.