Design, Synthesis, and Evaluation of New Ferroelectric Liquid Crystals

由于铁电液晶材料有望应用于高速开关显示器，因此铁电液晶的合成研究得到了广泛的开展。具有大的自发极化（Ps）和短的响应时间的FLC的合成设计导致在苄基位置具有手性中心和极性基团的光学活性化合物。FLC混合物掺杂的氰基环丙烷，氟环丙烷，γ-内酯，四氢呋喃，或1，3-二氧六环衍生物表现出大Ps。发现Ps的符号与化合物手性中心的绝对构型有很好的相关性。设计和合成的FLC的快速开关导致光学活性的氟取代的化合物，如氟烷基醚，氟烷基酯，氟链烷酸酯，和1-芳基氟代烷烃。特别是具有2-氟烷氧基、3-氟烷氧基或3-氟烷基作为手性链的苯基嘧啶实现了短响应时间。含有2，3-二氟烷氧基或2-氟-2-甲基烷酰氧基的化合物也被发现表现出大的Ps '。

Synthetic studies of ferroelectric liquid crystals (FLCs) have been extensively carried out, since FLC materials are expected to be applicable to displays with high speed switching. Synthetic design of FLCs with a large spontaneous polarization (Ps) and a short response time led to optically active compounds having a chiral center and a polar group at benzylic position. FLC mixtures doped with a cyanocyclopropane, fluorocyclopropane, gamma-lactone, tetrahydrofuran, or 1,3-dioxane derivative exhibited large Ps. The sign of Ps was found to well correlate to the absolute configuration of the chiral center of the compound. Design and synthesis of FLCs for fast switching led to optically active fluorine-substituted compounds like fluoroalkyl ethers, fluoroalkyl esters, fluoroalkanoic acid esters, and 1-arylfluoroalkanes. Especially phenylpyrimidines having 2-fluoroalkoxyl, 3-fluoroalkoxyl, or 3-fluoroalkyl group as a chiral chain realized short response time. Compounds containing 2,3-difluoroalkoxyl or 2-fluoro-2-methylalkanoyloxy group also were found to exhibit large Ps'.