Dynamic Photoswitching of Helical Inversion in Liquid Crystals Containing Photoresponsive Axially Chiral Dopants
Dynamic Photoswitching of Helical Inversion in Liquid Crystals Containing Photoresponsive Axially Chiral Dopants
复制标题
DOI：
10.1021/ja2088053
复制
发表时间：
2012-02-29
影响因子：
15
通讯作者：
Akagi, Kazuo
中科院分区：
文献类型：
--
作者：
Hayasaka, Hiroyuki;Miyashita, Tatsuaki;Akagi, Kazuo
手性开关是纳米材料中电子和光学性质的动态控制的一个有趣的现象。由于液晶在电光显示、光数据存储以及有机分子和聚合物的不对称合成中的潜在应用，光化学切换液晶（LC）中的手性的能力特别有吸引力。在这里，我们提出了一个动态的光开关的螺旋反转的手性液晶（N*-LC），含有光响应的轴向手性掺杂剂。合成了具有两个轴向手性联萘基团的新型光响应手性二噻吩基乙烯衍生物。联萘环的二面角通过二噻吩基乙烯部分的开放和闭合形式之间的光异构化而改变。二噻吩基乙烯衍生物作为手性掺杂剂诱导的N*-LC表现出可逆的光开关行为，包括N*-LC中的螺旋反转以及N*-LC和NH3-LC之间的相变。本发明的化合物是第一种通过二噻吩基乙烯部分的开放和封闭形式之间的光异构化在N*-LC中诱导螺旋反转的手性掺杂剂。
Chirality switching is intriguing for the dynamic control of the electronic and optical properties in nanoscale materials. The ability to photochemically switch the chirality in liquid crystals (LCs) is especially attractive given their potential applications in electro-optic displays, optical data storage, and the asymmetric synthesis of organic molecules and polymers. Here, we present a dynamic photoswitching of the helical inversion in chiral nematic LCs (N*-LCs) that contain photoresponsive axially chiral dopants. Novel photoresponsive chiral dithienylethene derivatives bearing two axially chiral binaphthyl moieties are synthesized. The dihedral angle of the binaphthyl rings changes via the photoisomerization between the open and closed forms of the dithienylethene moiety. The N*-LCs induced by the dithienylethene derivatives that are used as chiral dopants exhibit reversible photoswitching behaviors, including a helical inversion in the N*-LC and a phase transition between the N*-LC and the nematic LC. The present compounds are the first chiral dopants that induce a helical inversion in N*-LC via the photoisomerization between open and closed forms of the dithienylethene moiety.