含乙撑桥键二苯炔四环液晶的合成及性能

摘要

以4-烷基反式环己基甲酸为原料,经格氏、黄鸣龙、碘代及“一锅法”Sonogashira 偶联等反应,制备了10个含乙撑桥键二苯炔四环液晶化合物,其结构经 IR, NMR 和 MS 确认.利用差示扫描量热仪(DSC)、偏光显微镜(POM)和阿贝折光仪对目标化合物进行了性能测试.结果表明,目标化合物具有高清亮点(220~240℃)、宽向列相区间(59.6~99.6℃)和大光学各向异性(△n>0.3),其性能可满足液晶光学的应用要求.%Ten four-ring liquid crystals with ethylene and internal alkyne bridge were synthesized via Grignard reaction, Huang Minglong reduction, iodination, “one-pot” Sonogashira cross-coupling reaction with trans-4-alkyl-cyclohexane-carboxylic-acid as the starting substrate. The structures of the compounds were confirmed by infrared spectrometry(IR), nuclear magnetic resonance(NMR) and mass spectra(MS). The differential scan-ning calorimetry(DSC), polarising optical microscopy(POM) and Abbe refractometer were used to measure their properties. The results show that the compounds possess high clearing point (220-240 ℃), broad nematic phase(59. 6-99. 6 ℃) and high birefringence(△n>0. 3). These properties match the requirement of liquid crystal optics.