Dynamic molecular design for liquid-crystalline materials with a fast response speed

1.显示器件向列相液晶的研究进展：制备了一种新型的U型液晶分子，其中两个极性介晶基团通过catechol，1-{6-(3，4-difluorophenyloxy)hexyloxy}-2-{6-[4-(4-fluorophenyl)phenyloxy]hexyloxy}benzene，连接在一起，并研究了其电光性质。由宿主液晶(LC)和10wt%的U形化合物组成的向列相混合物的阈值电压明显低于宿主LC。发现该化合物显著降低了阈值电压，这是由于介电各向异性的增加。U型体系是一种降低液晶材料阈值电压的新途径。2.新型蓝相区手性液晶：我们设计了具有分子双轴性的手性液晶低聚物。我们准备了一系列同源的(R)-2，2‘-bis{6-[4-(2-(2-fluoro-4-butyloxyphenyl)pyrimidine-5-yl)phenyloxy]alkyloxy}-1，1’-…更多的是联苯醚。具有偶数个原子的联萘衍生物具有手性向列相，而具有奇数个原子的联萘衍生物在各向同性相和SMA相之间的相对较宽的温度范围内呈现蓝色相。3.具有层次结构的液晶低聚物：合成了一系列3，4-二羟基苯甲酸与3，4-二羟基苯甲酸相连的具有三个介晶基团的新型λ-形介晶化合物。发现4-氰基-4‘-联苯基-4’-3，4-bis{6-[4-(5-octylpyrimidm-2-yl)phenyloxy]hexyloxy}behzoate实现了无公度的形状记忆合金(SmA)相。我们制备了一系列同系的双致液晶α-(4-cyanobiphenyl-4‘-yloxy)-ω-[4-(5-alkylpyrimidine-2-yl)phenyl-4“-oxy]alkane(MPYnOCB)。发现在具有不同奇数间隔的双致液晶之间的某些二元混合物中产生了交指反斜近晶C(SmCanti)相。此外，在同向排列的样品的SmCanti相中观察到了条纹图案。该条纹图案随着样品温度的变化而扩展。较少

1.Development of nematic liquid crystals for display devices : A novel U-shaped liquid-crystalline molecule where two polar mesogenic groups are connected via catechol,1-{6-(3,4-difluorophenyloxy)hexyloxy}-2-{6-[4-(4-fluorophenyl)phenyloxy]hexyloxy}benzene, was prepared and the electrooptic properties were investigated. The threshold voltage of a nematic mixture consisted of a host liquid crystal (LC) and 10wt% of the U-shaped compound was found to be markedly lower than that of the host LC. Marked reduction in threshold voltage by the compound was found to be attributed to the increase in dielectric anisotropy. The U-shaped system is a novel approach for the reduction in the threshold voltage of liquid-crystalline materials.2.Novel chiral liquid crsyatls with a broad blue phase region : We designed chiral liquid crystal oligomers possessing molecular biaxiality. We prepared a homologous series of (R)-2,2'-bis{6-[4-(2-(2-fluoro-4-butyloxyphenyl)pyrimidine-5-yl)phenyloxy]alkyloxy}-1,1'- … More binaphthyl. The binaphthyl derivatives with an even number of atoms in the spacers showed a chiral nematic phase, however, those with an odd number of atoms showed a blue phase in a relatively wide temperature range between the isotropic and SmA phases. Then, we prepared a T-shaped compound, (R)-1-methylhepthy1-4'-{4-octyloxy-2-{11-[4-(5-octylpyrimidin-2-yl)phenoxy]undecanoyloxy}benzoyloxy}biphenyl-4-carboxylate, which was found to show a blue phase with a wide temperature range on cooling.3.Liquid crystal oligomers with a hierarchical structure : A homologous series of novel λ-shaped mesogenic compounds in which three mesogenic groups are connected to 3,4-dihyrdoxybenzoic acid has been prepared. 4-Cyanobiphenyl-4'-yl 3,4-bis{6-[4-(5-octylpyrimidm-2-yl)phenyloxy]hexyloxy}behzoate was found to realize an incommensurate SmA (SmAinc) phase. We prepared a homologous series of bimesogenic liquid crystals, α-(4-cyanobiphenyl-4'-yloxy)-ω-[4-(5-alkylpyrimidine-2-yl)phenyl-4"-oxy]alkane (mPYnOCB). The interdigitated anticlinic smectic C (SmCanti) phase was found to be induced for some binary mixtures betweeen the bimesogenic compounds with a different odd-numbered spacer. Furthermore, a striped pattern was observed in the SmCanti phase of a homeotropically aligned sample. The striped pattern was propagated when the temperature of the sample was varied. Less