多氟二苯乙炔类负性液晶化合物的合成

Synthesis of Multifluorotolane Negative Dielectric Ansotropy Liquid Crystals

以烷基环己基酮、1,2-二氟苯为起始原料(或以2,3-二氟烷基苯为起始原料),采用正丁基锂低温下制得金属锂化试剂,再经过系列反应制得4-烷基环己基-2,3-二氟碘苯(或4-烷基-2,3-二氟碘苯),其与4-乙氧基-2,3-二氟苯乙炔发生Sonogashira偶联反应,合成出了3种2,3,2′,3′-四氟二苯乙炔类液晶化合物。进行了产品的结构标定以及参数测定,确定该类化合物有较大的光学各向异性(Δn)和负值较大的介电各向异性(Δε),并且具有较宽的相变温度范围,可以用于改善液晶材料的响应速度和驱动电压。

This article reported three derivatives of 2,3,2′,3′ -terafluotolanes, which are prepared with 1-ethoxy-4-ethynyl-2,3-difluorobenzene and 1-alkylcyclohexyl-2,3-difluoro-4-iodobenzene （or 1-alkyl-2,3-difluoro-4-iodobenzene） by Sonogashira reactions.And the iodides are prepared with metal lithium reagents in low temperature from n-BuLi, alkylcyclohexanone and 1,2-difluorobenzene（or 1-alkyl-2,3-difluobenzene ） by a series of reactions. These compounds not only have large optical anisotropy（Δn） and large negative dielectric ansotropy（ΔE） ,but also have wider nematic phase temperature rang by a series photoelectricity test and DSC analysis. These materials can improve the respond time and drive voltage in LCD.