一种异丙烷桥键液晶材料的合成与性能

The Synthesis and Properties of a Liquid Crystal Compound Containing Isopropyl Bridge Bond

摘要:

以3-氟溴苯，对溴苯腈，丙基环己基甲基氯等为原料，经过格氏反应，Suzuki反应，witting反应，氢化反应等共七步反应最终合成出化合物2,6-二氟-4-[ 3 - 氟-4′-[1 - 甲基-2 -（4 - 丙基环己基）- 乙基] 联苯] 苯基二氟甲氧基-3,4,5-三氟苯（化合物（7）），其中格氏试剂与对溴苯腈的反应中溶剂选择二甲苯；锂化反应制备硼酸中，锂化反应时间选择2h；纯化后目标产物气相纯度为99.7%（mp：82.97-85.04℃），总收率约为30%，其结构经IR、1H-NMR及GC-MS确证。此化合物添加到液晶的基础配方中，能提高配方的双折射率 （Δn），降低其阀值电压（Vth）。

Abstract:

Using 1-bromo-3-fluorobenzene、4-bromobenzonitrile、1-(trans-4-propylcyclohexyl)-1-chloro-methane etc as starting materials, 2,6 - difluoro-4 - [3 - fluoro-4'-[1 - methyl - 2 - (4 -propylcyclohexyl) - ethyl]-biphenyl]phenyl difluoromethoxy-3, 4,5 - trifluorobenzene was synthesized by a method consisting of seven steps: Grignard reaction、Suzuki reaction、Witting reaction、hydrogenation reaction, etc. The reaction solvent of grignard reagent and 4-bromobenzonitrile was xylene；the optimum reaction time of lithiation reaction was 2h . The overall yield was about 30% and the purity reached 99.7%（GC）（mp：82.97-85.04℃）. Adding the compound into base composition of liquid crystal can improve the birefringence （Δ n），reduce the threshold voltage（Vth）.