2-烷基-5-(4-烷氧基)苯基含氮杂环液晶合成与性能研究

含氮芳环作为液晶分子的极性介晶基团,能有效增大分子的偶极矩和分子间的作用力,有利于形成近晶相液晶态,提高分子的介电各向异性,降低液晶的驱动电压。本文试图以嘧啶、吡啶为中心结构单元来增大化合物的偶极矩,设计合成了二个系列含嘧啶、吡啶的双芳环液晶化合物nOBMm、nOBPm系列共7个化合物;它们都经过IR、1 H-NMR、13 CNMR和MS光谱对其分子结构鉴定,经过差热分析仪(DSC)和偏光显微镜(POM)对其液晶性能进行检测。实验结果表明,所有化合物的分子结构均正确,具有较宽的近晶相态,可作为铁电液晶和高分子聚合物分散液晶材料配方组分,为进一步研究低能耗铁电液晶和聚合物分散液晶材料提供了实验素材。

Synthesis and properties of 2-n-alkyl-5-(4-n-alkoxyl) phenyl nitrogen aromatic ring compounds used as liquid crystal

The nitrogen-containing aromatic ring serves as the polar mesogenic group of the liquid crystal molecule, which can effectively increase the dipole moment of the molecule and improve molecular dielectric anisotropy, reduce LCD drive voltage. It also increases the interaction between molecules, which is conducive to the formation of smectic phase states. In this paper, we designed and synthesized two series of two aromatic liquid crystal compounds, nOBMm and nOBPm series, with pyrimidine and pyridine as the central element to increase the dipole moment of the compounds. They were identified by IR, ¹H-NMR, ¹³C-NMR and MS spectra, and their liquid crystal properties were detected by differential thermal analyzer (DSC) and polarizing microscope (POM). Experimental results show that the molecular structure of all compounds are right, and they have been a wide smectic phases. It can be used as the effective component of ferroelectric liquid crystal materials or the polymer dispersed liquid crystal materials, and provides experimental materials for further study on large dielectric anisotropy ferroelectric liquid crystal or polymer dispersed liquid crystal materials.