Helical Polyacetylenes Synthesized in Helical Sense and Pitch Controllable Chiral Nematic Liquid Crystal with Unprecedented Temperature Dependence
Helical Polyacetylenes Synthesized in Helical Sense and Pitch Controllable Chiral Nematic Liquid Crystal with Unprecedented Temperature Dependence
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DOI：
10.1021/ma0703655
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发表时间：
2007-06
期刊：
影响因子：
5.5
通讯作者：
M. Goh;T. Matsushita;M. Kyotani;K. Akagi
中科院分区：
文献类型：
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作者：
M. Goh;T. Matsushita;M. Kyotani;K. Akagi
我们合成了两种新型手性化合物D-1和D-2−D-5，其中D-1是含(S)构型的不对称中心手性化合物，D-2−D-5是所谓的双手性化合物，由(S)构型的轴向手性双萘基部分和(S)-、(S)-、(R)-和外消旋构型的不对称中心部分组成，分别与6、12、12和12的亚甲基间隔物相连。采用这些手性化合物作为手性掺杂剂，诱导出了手性向列相液晶（N*-LCs）。含有双手性掺杂剂D-3的N*-LC，简称为带D-3的N*-LC（体系2），在偏光显微镜（POM）下，当温度从0℃升高到30℃时，其螺旋螺距（螺旋扭转功率）显著增加。这是由于具有相反螺旋方向的双手性基团之间的扭力大大抵消，尽管它们都具有相同的(S)构型。同时，N*-LC包括两种类型…
We have synthesized two types of novel chiral compounds, D-1 and D-2−D-5, where D-1 is an asymmetric center-containing chiral compound of (S)-configuration, and D-2−D-5 are so-called double chiral compounds consisting of axially chiral binaphthyl moiety of (S)-configuration and asymmetric center moieties of (S)-, (S)-, (R)- and racemic configuration, linked with methylene spacers of 6, 12, 12 and 12, respectively. These chiral compounds were adopted as chiral dopants to induce chiral nematic liquid crystals (N*-LCs). The N*-LC including the double chiral dopant D-3, abbreviated as N*-LC with D-3 (system 2), showed an extraordinary increase in helical pitch (decrease in helical twisting power) in polarizing optical microscope (POM) when the temperature increased from 0 to 30 °C. This is due to a substantial cancellation in twisting power between the double chiral moieties having opposite screw directions, although both of them have the same (S)-configuration. Meanwhile, the N*-LC including the two types of...