• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Advanced Functional Materials >Ferrocene-Containing Optically Active Liquid-Crystalline Side-Chain Polysiloxanes with Planar Chirality
【24h】

Ferrocene-Containing Optically Active Liquid-Crystalline Side-Chain Polysiloxanes with Planar Chirality

机译：平面手性含二茂铁的旋光性液态液晶侧链聚硅氧烷

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Optically active liquid-crystalline side-chain polysiloxanes have been prepared by grafting planar chiral ferrocene-based vinyl monomers onto commercially available polyhydrosiloxane. Two ferrocene monomers have been synthesized: a linear-type monomer, which displays a monotropic chiral smectic C (S_(C~*)) phase and enantiotropic smectic A (S_A) and chiral N (N~*) phases, and a laterally branched monomer, which shows an enantiotropic N~* phase. X-ray diffraction analysis indicates a mono-molecular organization of the monomeric units within the smectic layers. The polymers retain the liquid-crystalline phases of their corresponding monomers. The UV-vis and circular dichroism (CD) spectra are in agreement with the structure of the monomers and polymers. The molar absorption coefficient (ε) and molar circular dichroic absorption coefficient (Δε) values of the polymers are proportional to the number of monomeric units grafted onto them. The absolute configuration of the ferrocene carboxylic acid intermediate, used to synthesize the monomers, has been determined on the basis of CD spectra. The helical twisting power (HTP) of the nematogenic monomer and polymer have been determined in E7, and indicate that such materials could be used as chiral dopants. Finally, this study demonstrates that the nature of chiral phases can be controlled by structural engineering of the organic groups only, with ferrocene acting as the source of chirality.
机译：光学活性的液晶侧链聚硅氧烷是通过将平面手性二茂铁基乙烯基单体接枝到可商购的聚氢硅氧烷上而制备的。合成了两种二茂铁单体：线性型单体，具有单向性手性近晶C（S_（C〜*））相和对映性近晶A（S_A）和手性N（N〜*）相，以及侧向支化单体，表现出对映的N〜*相。 X射线衍射分析表明近晶层内的单体单元为单分子组织。聚合物保留其相应单体的液晶相。紫外可见光谱和圆二色性（CD）光谱与单体和聚合物的结构一致。聚合物的摩尔吸收系数（ε）和圆形二色性摩尔吸收系数（Δε）值与接枝到它们上的单体单元的数量成正比。已经基于CD光谱确定了用于合成单体的二茂铁羧酸中间体的绝对构型。已在E7中确定了产线单体和聚合物的螺旋扭曲力（HTP），表明这种材料可用作手性掺杂剂。最后，该研究表明手性相的性质只能通过有机基团的结构工程来控制，其中二茂铁作为手性的来源。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号