Flexible H-bonded liquid-crystals with wide enantiotropic blue phases
摘要:
新型肉桂酸衍生 H 键液晶的对映体 BP*s 很容易制备。只需改变供体-受体比例,即(S)-4-(2-辛酰氧基)肉桂酸与 4-(4-丙基环己基)苯基异烟酸酯的比例,生成的 BP 温度范围就会随之扩大,最宽范围约为 10 °C,这在各向同性 BP 材料中是很少见的。密度-官能团理论计算的优化结果表明,肉桂酸衍生介质具有弯曲形状,因此有利于稳定各向同性蓝相。
Ferroelectric Liquid Crystals. Part 9. Laterally substituted phenyl benzoates incorporating atrans-1,4-disubstituted cyclohexane ring
作者:Stephen M. Kelly
DOI:10.1002/hlca.19890720319
日期:1989.5.3
About 65 diverse phenylbenzoatesincorporating a trans-1,4-disubstituted cyclohexanering and at least one lateral substituent have been synthesised. The dependence of the liquid-crystal transition temperatures of these materials on various lateral substituents (F, Cl, CN, and Br) in different positions of the esters has been investigated systematically. The influence of up to four F-atoms in various
Thermally, photochemically and electrically switchable reflection colors from self-organized chiral bent-core liquid crystals
作者:Manoj Mathews、Rafael S. Zola、Deng-ke Yang、Quan Li
DOI:10.1039/c0jm03479g
日期:——
We report the synthesis and characterization of two new chiral 1,3-phenylene based five ring bent-core mesogens that combine the unique electro-optic characteristics of banana-shaped molecules with chiroptic properties. Azobenzene moiety incorporated as a linking unit in one of the rigid arms renders trans–cis isomerization property to the molecules while chirality is introduced by tethering chiral aliphatic terminal chains. Both compounds can self-organize into helical superstructure, i.e. cholesteric mesophase, which can selectively reflect light. The novelty of the helical self-organized superstructure reported here lies in its low molecular weight single component molecular system that is truly multifunctional so that the reflection band is tunable by three different external stimuli, i.e. temperature, light and electric field. A red shift in reflection colors is obtained by changing the temperature on cooling and by UV irradiation while a blue shift is seen by electrical field application. Due to the high applicability of azobenzene-doped liquid crystalline systems, we also evaluated the efficiency of these chiral bent-core molecules as chiral transfer agents and found that they behave similar to rod-shaped dopants whose chirality is a consequence of the presence of one chiral center.
New mesogenic compounds exhibiting unique, so called orthoconic, behavior at the synclinic smectic SmC* phase have been obtained.
已获得表现出在同向螺旋相SmC*阶段具有独特的所谓正圆锥行为的新向列相化合物。
Ferroelectric Liquid Crystals. Part 2. Chiral phenyl benzoates incorporating atrans-1,4-disubstituted cyclohexane ring
作者:Stephen M. Kelly、Richard Buchecker
DOI:10.1002/hlca.19880710218
日期:1988.3.16
About forty novel phenylbenzoates also incorporating a trans-1,4-disubstituted cyclohexanering and a chiral centre have been prepared. The dependence of the liquid-crystal transition temperatures of this new class of compounds on lateral substituents, diverse central linkages, chain lengths, and position of the chiral centre has been studied systematically. The synthesis and liquid-crystal transition
Apolar Bimesogens and the Incidence of the Twist-Bend Nematic Phase
作者:Richard J. Mandle、Edward J. Davis、Craig T. Archbold、Constantin C. A. Voll、Jessica L. Andrews、Stephen J. Cowling、John W. Goodby
DOI:10.1002/chem.201500423
日期:2015.5.26
The nematictwist–bendphase (NTB) was, until recently, only observed for polar mesogenic dimers, trimers or bent‐core compounds. In this article, we report a comprehensive study on novel apolar materials that also exhibit NTB phases. The NTB phase was observed for materials containing phenyl, cyclohexyl or bicyclooctyl rings in their rigid‐core units. However, for materials with long (>C7) terminal