The dramatic influence of the location of bend and of lateral fluoro substitution on the mesomorphic properties of angular chiral esters based on a 1,3-disubstituted benzene ring
The dramatic influence of the location of bend and of lateral fluoro substitution on the mesomorphic properties of angular chiral esters based on a 1,3-disubstituted benzene ring
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弯曲位置和侧向氟取代对基于 1,3-二取代苯环的角手性酯的介晶性质的显着影响
DOI：
10.1039/b923267b
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发表时间：
2010
影响因子：
--
通讯作者：
Fergusson K
中科院分区：
文献类型：
--
作者：
Fergusson K
详细介绍了一系列以1，3-二取代苯为基元的三环和四环手性酯的合成及其介晶性质。这些材料都偏离了液晶的通常线性分子结构，因此本质上都是有角的。其中一些材料在分子末端有弯曲，在那里链偏离了正常的线性排列，因此“曲棍球棒”分子结构可能是一个准确的描述。其他材料有一个真正的双核心结构，其中弯曲是朝着分子的中心，因此最好被称为“回旋镖”形状。在所有的情况下，有趣的中间相形态和转变温度的比较，发现，无论是在各种角材料，并与他们的线性类似物。特别是，在新的角材料的横向氟取代的转变温度的影响被发现是完全不同的已知的线性类似物中发现的。这项工作的一部分，一个更大的正在进行的研究计划，以调查介晶和手性相关的性能的角度液晶。研究表明，当弯曲靠近分子中心时，母体化合物中不可能有介晶性，然而，此类化合物的侧向氟取代有利于液晶相的产生。当分子弯曲是由于芯末端的末端单元时，则产生令人惊讶的高清亮点，并且发现这种材料显示出高倾斜角的潜力和朝向螺旋中间相的强烈趋势。这些后面的实施例的横向氟取代一致地导致显著更高的清亮点，这与先前在已知的线性分子结构的液晶中报道的行为形成鲜明对比。
The synthesis and mesomorphic properties of a range of 3-ring and 4-ring chiral esters based on a 1,3-disubstituted benzene unit are detailed. These materials all deviate from the usual linear molecular architecture of liquid crystals, and hence are all angular in nature. Some of these materials have the bend right at the end of the molecule where the chain deviates from the normal linear arrangement, and hence a ‘hockey stick’ molecular architecture is perhaps an accurate description. Other materials have a genuine bent-core construction where the bend is towards the centre of the molecule, and hence are best termed as ‘boomerang’ shape. In all cases, interesting comparisons of mesophase morphology and transition temperatures were found, both between the various angular materials and with their linear analogues. In particular, the influence on transition temperatures of lateral fluoro substitution in the novel angular materials was found to be wholly different to that found in the known linear analogues. The work forms part of a larger on-going research programme to investigate the mesomorphic and chirality-dependent properties of angular liquid crystals. The research revealed that no mesomorphism in parent compounds is possible when the bend is close to the centre of the molecule, however, lateral fluoro substitution of such compounds facilitates the generation of liquid crystal phases. Where the molecular bend is as a consequence of the terminal unit at the end of the core, then surprisingly high clearing points resulted, and such materials were found to show the potential for a high tilt angle, and a strong tendency towards helical mesophases. Lateral fluoro substitution of these latter examples resulted consistently in significantly higher clearing points, which is in marked contrast to the behaviour reported previously in known liquid crystals of linear molecular architectures.
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DOI：
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发表时间：
1997
期刊：
影响因子：
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作者：
A. Seed;M. Hird;P. Styring;H. Gleeson;J. T. Mills
通讯作者：
J. T. Mills
带有全氟丁酰氧基端链的高倾斜反铁电酯：侧向氟取代基对介晶行为、倾斜角和自发极化的影响
DOI：
--
发表时间：
2006
期刊：
影响因子：
--
作者：
Andrew I. Stipetic;J. Goodby;M. Hird;Y. Raoul;H. Gleeson
通讯作者：
H. Gleeson
影响因子：
8.6
作者：
R. A. Reddy;V. Raghunathan;B. K. Sadashiva
通讯作者：
R. A. Reddy;V. Raghunathan;B. K. Sadashiva
胆甾型结构-II 化学意义
DOI：
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发表时间：
1966
期刊：
影响因子：
--
作者：
J. L. Fergason;N. N. Goldberg;R. Nadalin
通讯作者：
R. Nadalin
影响因子：
--
作者：
Hird, M;Goodby, JW;Toyne, KJ
通讯作者：
Toyne, KJ