含氫鍵彎曲雙成份藍相液晶混合物之合成及研究

Abstract

本文實驗合成一系列吡啶基分子與羧酸基分子，利用H1-NMR EA作為結構鑑定。再藉由氫鍵鍵結形成彎曲狀超分子，並以POM 電性量測探討其液晶行為。 我們成功的以吡啶基分子與羧酸基分子形成超分子得到向列相(N)，並導入F官能基於羧酸基分子後，影響其超分子的液晶像溫度範圍。再將其掌性結構導入羧酸基分子中，使N相轉變為N*相。 接著，我們將吡啶基分子與含掌性結構且有F官能基羧酸基分子以不同的莫爾百分比混摻，在羧酸基分子過量的情形下，可因自身氫鍵而鍵結成棒狀的結構。在C9IIIPy-A2F*與C7IIIPy-A2F*的系列中，成功觀察到了BPI/II的藍相結構，在C9IIIPy-A2F*的羧酸基分子佔其莫爾百分比60% ~ 80%可以觀察到藍相，其中以70%具有較長的藍相，約8℃的溫度範圍。在C7IIIPy-A2F*的羧酸基分子佔其莫爾百分比60% ~ 70%時亦可觀察到藍相，其中以60%具有較長的藍相，約7℃的溫度範圍。

We synthesized a series of pyridine-based molecules and carboxylic acid molecules. The chemical structures of these compounds were characterized by H1-NMR and EA. They consisted of hydrogen bonding supramolecular diad mixtures. The liquid crystalline phases and mesomorphic behavior of all compounds were identified from the results of POM and Electro-optical measurement. Pyridyl molecules connected to a simple carboxylic acid molecule by a hydrogen bond have a nematic phase. The F functional group in carboxylic acid-based molecules affects their supramolecular liquid crystal temperature range. As the carboxylic acid molecules have chiral structure, the nematic phase switches to the chiral nematic phase. Next, we mixed pyridine-based molecules with carboxylic acid molecules with chiral structures and F functional groups in different molar percentage blends. In the case of excess carboxylic acid molecules, the carboxylic acid molecules will form a rod-like structure with another via a hydrogen bond. This series of C9IIIPy-A2F * and C7IIIPy-A2F * have blue phase (BPI /II). The series of C9IIIPy-A2F * have blue phase when carboxylic acid molecules are 60 mol% to 80 mol%. The blue phase temperature range is about 8℃. The series of C7IIIPy-A2F * also have blue phase when carboxylic acid molecules are 60 mol% to 70 mol%. The blue phase temperature range is about 7℃.