Beltrán Eduardo, Cavero Emma, Barberá Joaquín, Serrano José Luis, Elduque Anabel, Giménez Raquel
Department of Organic Chemistry, Facultad de Ciencias-Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, Pedro Cerbuna 12, 50009, Spain.
Chemistry. 2009 Sep 14;15(36):9017-23. doi: 10.1002/chem.200901154.
Chiral polycatenar 1H-pyrazoles self-assemble to form columnar mesophases that are stable at room temperature. X-ray diffraction and CD studies in the mesophase indicate a supramolecular helical organization consisting of stacked H-bonded dimers. The liquid-crystalline compounds reported are 3,5-bis(dialkoxyphenyl)-1H-pyrazoles that incorporate two or four dihydrocitronellyl chiral tails. It can be observed that the grafting of these branched chiral substituents onto the 3,5-diphenyl-1H-pyrazole core has a beneficial role in inducing mesomorphism, because isomeric linear-chain compounds are not liquid crystalline; this is not the usual scheme of behavior. Furthermore, the molecular chirality is transferred to the columnar mesophase, because preferential helical arrangements are observed. Films of the compounds are luminescent at room temperature and constitute an example of the self-organization of nondiscoid units into columnar liquid-crystalline assemblies in which the functional molecular unit transfers its properties to a hierarchically built superstructure.
手性多链节1H-吡唑自组装形成在室温下稳定的柱状中间相。中间相的X射线衍射和圆二色性研究表明，存在由堆叠的氢键二聚体组成的超分子螺旋结构。报道的液晶化合物是3,5-双（二烷氧基苯基）-1H-吡唑，其含有两个或四个二氢香茅基手性链。可以观察到，将这些支链手性取代基接枝到3,5-二苯基-1H-吡唑核上对诱导介晶性具有有益作用，因为异构线性链化合物不是液晶；这不是通常的行为模式。此外，分子手性被传递到柱状中间相，因为观察到了优先的螺旋排列。这些化合物的薄膜在室温下发光，并且构成了非盘状单元自组装成柱状液晶组装体的一个例子，其中功能性分子单元将其性质传递到分层构建的超结构中。
