星形液晶的分子结构对其有序排列的影响

Influence of Star-Shaped Liquid-Crystal Molecular Structure on Their Ordered Structure

以1,2,4-丁三醇(C)为手性中心,4’-(4-(三氟甲基苯甲酸基)联苯)羧酸(B1)、6-(4-(4-乙氧基苯甲酸基)苯)己二酸单酯(B2)为侧臂,采用N,N’-二环己基碳化二亚胺/4-二甲氨基吡啶(DCC/DMAP)成酯法,合成了均臂星形与杂臂星形液晶FJ0~FJ3。通过红外光谱、核磁共振、偏光显微镜、差示扫描量热、变温X射线衍射等手段对所合成的星形液晶的分子结构及其有序排列进行了研究。结果表明,手性中心使均臂星形液晶(FJ0和FJ3)产生螺旋状的有序排列,而杂臂星形液晶(FJ1和FJ2)并未受手性中心的影响形成螺旋结构,而是形成了一维有序的向列相结构。

Four star-shaped liquid crystals(FJ0 ~ FJ3),were synthesized using 1,2,4-butanetriol(C) as chiral core,4'-(4-(trifluoromethyl) benzoyloxy) biphenyl-4-carboxylic acid(B1) and 6-(4-(4-ethoxybenzoyloxy) henoxy)-6-oxohexanoic acid(B2) as side arms and N,N'dicyclo-hexyl carbodiimide /4-dimethylamino pyridine(DCC / DMAP) as dehydration agent.The chemical structures and ordered structure of star-shaped liquid crystal FJ0 ~ FJ3 were investigated by means of FT-IR,1H-NMR,POM,DSC,and XRD.Experiment results show that spiral ordered structures are formed by introducing chiral core to star-shaped liquid crystals(FJ0 and FJ3).But spiral structures could not be formed by introducing chiral core to heteroarm star-shaped liquid crystals(FJ1 and FJ2).FJ1 and FJ2 exhibit one dimensional arrangement of nematic phase.