The effect of a thiophene ring in the outer position on mesomorphic properties of the bent-shaped liquid crystals
作者:Václav Kozmík、Petr Polášek、Arnošt Seidler、Michal Kohout、Jiří Svoboda、Vladimíra Novotná、Milada Glogarová、Damian Pociecha
DOI:10.1039/c0jm00375a
日期:——
Novel bent-shaped compounds with the naphthalene central core possessing an outer thiophene unit in the lengthening arm were synthesized. Mesomorphic behaviour of new materials was studied using optical polarising microscopy, DSC, and electrooptic methods. The structures of mesophases were identified by X-ray diffraction and the structural parameters established. In the case of the thiophene unit in one molecular arm (the phenyl in the opposite arm) we succeeded in obtaining mesogenic properties for all types of lateral substitutions on the central naphthalene core. All non-substituted compounds and materials with the central core substituted by CH3 or Cl exhibited the B2 phase. The B7 phase has been observed for all compounds with CN-substituted central core. Materials with the thiophene unit in both lengthening arms were not liquid crystalline except for the CN-substituted compound exhibiting the B7 phase. Mesomorphic properties of compounds with the thiophene are compared with those detected on analogous materials with the phenyl ring.
我们合成了具有萘中心核的新型弯曲形化合物,在加长臂中具有一个外部的噻吩单元。我们使用光学偏振显微镜、DSC和电光方法研究了新材料的介形行为。通过X射线衍射确定了介形结构,并确定了结构参数。对于分子臂中的噻吩单元(另一臂中的苯基),我们成功获得了中心萘核上所有类型侧向取代的介形特性。所有未取代的化合物和中心核被CH3或Cl取代的材料都表现出B2相。对于所有中心核被CN取代的化合物,我们观察到了B7相。除了表现出B7相的CN取代化合物外,在两个加长臂中具有噻吩单元的材料不是液晶。我们将具有噻吩的化合物的介形特性与具有苯环的类似材料上的介形特性进行了比较。