Achiral bent-core azo compounds: effect of different types of linkage groups and their direction of linking on liquid crystalline properties
作者:N. G. Nagaveni、Arun Roy、Veena Prasad
DOI:10.1039/c2jm30709j
日期:——
We report, the design, synthesis and mesomorphic properties of six new homologous series of achiral bent-core compounds. In this study, we have investigated the effect of different types of linkage groups and their direction of linking, on the mesomorphic properties of azo functionalized compounds. The molecular structures of these newly synthesized compounds are characterized by spectroscopic methods. The liquid crystalline properties are studied using polarizing optical microscopy, differential scanning calorimetry, X-ray diffraction and electro-optical studies. We observed a variety of mesophases in these compounds, viz. N, B1, B2, SmA, SmAdPAetc. From our investigations, we found that the type and the direction of the linkage group affects the thermal range or even sometimes the nature of the mesophase itself. We have also carried out photo-induced studies on the B2 mesophase of some of the selected compounds and found that the reversal in the direction of linkage groups does affect the photochromic properties of the compounds.
我们报告了六个新的同源系列非手性弯曲核化合物的设计、合成和介观性质。在这项研究中,我们探讨了不同类型的连接基团及其连接方向对偶氮官能团化合物中间形态性质的影响。这些新合成化合物的分子结构是通过光谱方法表征的。使用偏振光学显微镜、差示扫描量热法、X 射线衍射和电光研究了液晶特性。我们在这些化合物中观察到了多种介相,即 N、B1、B2、SmA、SmAdPA 等。通过研究,我们发现连接基团的类型和方向会影响热范围,有时甚至会影响介相本身的性质。我们还对一些选定化合物的 B2 介相进行了光诱导研究,发现连接基团方向的逆转确实会影响化合物的光致变色特性。