Choi Suk-Won, Kang Sungmin, Takanishi Yoichi, Ishikawa Ken, Watanabe Junji, Takezoe Hideo
Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Tokyo, Japan.
Chirality. 2007 May 5;19(4):250-4. doi: 10.1002/chir.20358.
Enantioselective segregation has been attained in the Bx phase of a novel substituted oxadiazole achiral banana-shaped liquid crystal (LC) without introducing any chiral species. This bent-core molecule exhibits LC polymorphism; the higher temperature nematic (N) phase and the lower temperature banana smectic phase (Bx phase), in which spontaneous chiral segregation with (+) and (-) chiral domains occurs with equal probabilities. In twisted cell geometries, extrinsically induced twisted N structures are formed and result in intrinsically chiral conglomerate when the temperature is decreased from N to Bx. The observed optical activity in homochiral Bx phase is comparable to those theoretically predicted and is proportional to the cell thickness.
在一种新型取代恶二唑非手性香蕉形液晶（LC）的Bx相中实现了对映选择性分离，且未引入任何手性物质。这种弯曲核分子表现出液晶多态性；较高温度的向列相（N相）和较低温度的香蕉近晶相（Bx相），其中（+）和（-）手性畴的自发手性分离以相等的概率发生。在扭曲的盒状几何结构中，当温度从N相降低到Bx相时，会形成外在诱导的扭曲N结构，并导致内在手性聚集体。在手性纯的Bx相中观察到的旋光性与理论预测值相当，且与盒厚度成正比。
