含氫鍵彎曲雙成份藍相液晶混合物之合成及研究

Synthesis and Study of Blue Phase Liquid Crystalline Mixtures Consisting of H-Bonded Bent-Core Diads

周予強(Yu-Chiang Chou)

指導教授 ： 林宏洲 ； 楊勝雄

國立交通大學/光電學院/影像與生醫光電研究所/碩士(2012年)

https://doi.org/10.6842/NCTU.2012.00722

摘要

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。

關鍵字

氫鍵 ； 彎曲狀液晶 ； 超分子 ； 藍相液晶

並列摘要

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℃.

並列關鍵字

hydrogen bond ； bent-core liquid crystal ； supramolecular ； blue phase liquid crystal

參考文獻

[4] S. Kumar, Liquid crystals: experimental study of physical properties and phase transitions, New York, 2001, p.49.

[7] N. A. Clark and S. T. Lagerwall, Appl. Phys. Lett. 1980, 36, 899

[10] R. A.Reddy, C. Tschierske. J. Mater. Chem., 2006, 16, 907.

[12] T. Kato, J M J. Frechet. J. Am. Chem. Soc., 1989, 111, 8533.

[13] T. Kato, Structure &Bonding, 96; Berlin :Springer2 Verlag, 2000, 85