Synthesis and mesomorphic properties of new V-shaped shape-persistent nematogens containing a thiazole or a thiadiazole bending unit
摘要:
我们合成了两个系列的新型 V 形分子,其中包含一个中央噻唑或噻二唑弯曲单元。这种设计基于形状持久的苯乙炔支架,这些支架以高区域选择性逐步连接到顶角约为 160°的非对称碘和溴官能化弯曲核心。分子工程的结果是,材料完全呈现向列液晶相(单向或对映)。通过偏振光学显微镜(POM)、差示扫描量热法(DSC)和 X 射线衍射法对相行为进行了研究。
Synthesis and mesomorphic properties of new V-shaped shape-persistent nematogens containing a thiazole or a thiadiazole bending unit
摘要:
我们合成了两个系列的新型 V 形分子,其中包含一个中央噻唑或噻二唑弯曲单元。这种设计基于形状持久的苯乙炔支架,这些支架以高区域选择性逐步连接到顶角约为 160°的非对称碘和溴官能化弯曲核心。分子工程的结果是,材料完全呈现向列液晶相(单向或对映)。通过偏振光学显微镜(POM)、差示扫描量热法(DSC)和 X 射线衍射法对相行为进行了研究。
The synthesis and thermotropic properties of novel V-shaped molecules having a central 1,3,4-thiadiazole core with a bend-angle of 160 are reported. The compounds consist of a shape-persistent oligo(phenylene ethynylene) scaffold with lateral alkyloxy substituents. One of the terminal aromatic units possesses an alkoxy chain capped by an ethyl ester group while the second terminus is a pyridyl group. They exhibit enantiotropic nematic phases and are characterized by polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction. Results from conoscopy indicate a biaxial nature of the nematic phase near room temperature. DFT calculations of dipole moments and molecular polarizabilities are used to substantiate the experimental findings.