Photosensitive phasmid-like liquid crystalline materials with unusual mesomorphic behavior
作者:Nagendrappa Gowdru Nagaveni、Meenal Gupta、Arun Roy、Veena Prasad
DOI:10.1039/c0jm01858a
日期:——
We report on the synthesis and mesomorphic properties of five new series of azo functionalized phasmid-like compounds formed by covalent bonding. They consist of both symmetric and non-symmetric molecules. Most of these compounds are found to be liquid crystalline, with unusual behavior. They exhibit mainly nematic, columnar and smectic mesophases. In addition to these phases, in few cases, we observed some higher order mesophases as well. The nature of these mesophases is investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. We obtained unconventional XRD patterns for the nematic phase in some of these compounds. Based on the experimental results, we propose a model for the molecular arrangement in the columnar phase to be center rectangular. Dielectric and optical transmission measurements in the mesophases of one of the representative compounds are also reported. We have made a qualitative investigation into the photosensitivity of the mesophases of one of these compounds.
我们报告了五系列新型偶氮官能化相虫类化合物的合成及其介质性质。这些化合物包括对称和非对称分子。大多数化合物被发现为液晶,具有异常行为。它们主要表现出向列相、柱状相和液晶层相。除了这些相,少数情况下,我们还观察到一些高阶介质相。这些介质相的性质通过偏振光学显微镜(POM)、差示扫描热量法(DSC)和X射线衍射(XRD)研究进行了调查。我们在一些化合物的向列相中获得了非常规的XRD图谱。根据实验结果,我们提出了柱状相中分子排列的模型为中心矩形。此外,还报告了代表性化合物在介质相中的介电和光透射测量。我们对其中一个化合物的介质相的光敏性进行了定性研究。