应用化学2017，Vol.34Issue(6)：676-684,9.DOI:10.11944/j.issn.1000-0518.2017.06.160397
三氟丙炔基类液晶的合成及性能
Synthesis and Properties of Liquid Crystals with 3,3,3-Trifluoropropynyl Terminal Group
摘要
Abstract
Sixteen liquid crystals with 3,3,3-trifluoropropynyl terminal group were reported.The target compounds were synthesized via a series of reactions including the zinc reagent's reaction, Suzuki cross-coupling, and the elimination reaction of HCl.The total yields are more than 67%, and the gas chromatograph(GC) purities are more than 99.5%.The structures of the target compounds were characterized by infrared spectroscopy(IR), nuclear magnetic resonance(NMR) and mass spectrometry(MS).Moreover, their thermal properties were investigated by differential scanning calorimetry(DSC) and polarizing microscope(POM).The results show that the biphenyl type of compounds exists no liquid crystal phase while the terphenyl compounds have a smectic A phase.The melting points drop with the increase in the number of alkyl chain carbon.In terms of physical properties, these compounds have large Δε value(12.61~21.94), and the value of Δε is increased by trifluoromethyl and lateral fluorine substitution.The Δn value is about 0.19~0.29 with the increase of the number of benzene rings.The γ1 value is in the range from 49.9 to 468.0 mPa·s, which goes up with the increase of the number of benzene rings.Compounds 4n have high Δε(>19.2), high ε⊥(>10.3), and low Δε/ε⊥(<2).The influence of the position of the acetylenic bond on the properties of this kind of liquid crystal was discussed by simulation.All of the above properties of these liquid crystals have been proved to be useful for tuning the birefringence and the dielectric anisotropy of the liquid crystal mixtures, and these liquid crystals also have good value for FFS(fringe-field switching) display mode by the improvement of molecular structure.关键词
液晶/边缘场开关显示模式/三氟丙炔基/介电各向异性/双折射率/旋转粘度Key words
liquid crystal/liquid crystal mode of fringe-field switching/trifluoropropynyl/dielectric anisotropy/birefringence/rotational viscosity分类
化学化工引用本文复制引用
宋宽广,李建,高潮,胡明刚,安忠维..三氟丙炔基类液晶的合成及性能[J].应用化学,2017,34(6):676-684,9.基金项目
国防基础科研基金资助项目(B1120132028) （B1120132028）
Supported by Defense Industrial Technology Development Program of China(No.B1120132028) （No.B1120132028）
