COOPERATIVITY AND TRANSFER OF CHIRALITY IN LIQUID-CRYSTALLINE POLYMERS
COOPERATIVITY AND TRANSFER OF CHIRALITY IN LIQUID-CRYSTALLINE POLYMERS
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DOI：
10.1002/anie.199401881
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发表时间：
1994-02-01
期刊：
影响因子：
--
通讯作者：
ZENTEL, R
中科院分区：
文献类型：
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作者：
WULFF, G;SCHMIDT, H;ZENTEL, R
对手性液晶化合物的兴趣是由于液晶相的超结构中的手性可以由分子水平的手性诱导的事实。这可以导致形成具有从几百nm到几μ m的节距的螺旋超结构。这些相的材料性质也是特别感兴趣的，例如，通过近晶C* 相的选择性光反射或铁电性。低分子量化合物的这种热致相是众所周知的，侧链聚合物的那些也是众所周知的。在后一种情况下，手性基团主要存在于分支基团中。它很少出现在间隔物或基质中。另一方面，在主链中具有手性的热致性侧链聚合物是未知的。我们的目的是合成液晶聚乙烯基化合物，它具有由主链的构型产生的手性。[4.因此，可以研究手性聚合物链与非手性介晶的偶联和去偶联。由此，我们发现了主链上独特的立体化学中心的基团结构与手性转移到介晶上之间令人惊讶的独特关系（图1）。a B f
The interest in chiral liquid-crystalline compounds is due to the fact that chirality in the superstructure of the liquid-crystalline phase can be induced by chirality at a molecular level. This can result in the formation of helical superstructures with pitches from several hundred nm to several pm. The material properties of such phases are also of particular interest, for example, the selective reflection of light by the cholesteric phase or the ferroelectricity of the smectic C* phase. Such thermotropic phases of compounds of low molecular weight are wellknown, as are those of side chain polymers.['] In the latter case, the chiral group is mainly found in the branch group.['] It is rarely seen in the spacer [''or in the me~ ogen.[~ l On the other hand, thermotropic side chain polymers with chirality in the main chain are as yet unknown. Our intention was to synthesize liquid-crystalline polyvinyl compounds, which have chirality that arises from the configuration of the main chain.[4.'I It is thus possible to investigate the coupling and decoupling of the chiral polymer chains with the achiral mesogens. From this we found a surprisingly distinct relationship between the structure of the groups at the uniquely defined stereochemical centers of the main chain and the transfer of chirality onto the mesogens (Fig. 1). a b f