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    高師機構典藏 NKNUIR > 理學院 > 化學系 > 博碩士論文 >  Item 987654321/1505
    Please use this identifier to cite or link to this item: http://ir.nknu.edu.tw/ir/handle/987654321/1505

    題名: 由4-羥基苯醋酸丁醋與4-烷氧基聯苯酸所構成之液晶化合物合成
    Synthesis of liquid crystal compounds composed of n-Butyl 4-hydroxyphenylacetate and 4-alkoxybiphenyl carboxylic acid.
    Authors: 張雅玲
    Ya-Ling Chang
    貢獻者: 蔡文亮
    Wen-Liang Tsai
    Keywords: 液晶化合物 4-羥基苯醋酸丁醋 4-烷氧基聯苯酸
    liquid crystal 4-alkoxybiphenyl carboxylic acid n-Butyl 4-hydroxyphenylacetate
    Date: 2007-05-18
    Issue Date: 2010-04-29 14:16:47 (UTC+8)
    Abstract: 本實驗室於2000年,依照Gray等人的方式合成芐基4-(4’-辛氧基聯苯-)4-羰氧基苯酸酯,發現該液晶分子出現層列A 相及層列C相。2003年,本實驗室把原本的芐基轉換為環己甲基及環戊甲基,研究結果顯示,此兩系列分子(C數為2~10)仍具有層列A相,部份分子亦具有層列C相(C數6~10)。
    本論文將非長鏈烷氧基端的另一側末端基改為丁氧基乙羰基,並同時改變結構中的長鏈烷基碳數,合成化合物1~10。實驗結果發現,末端基分子4-羥基苯醋酸正丁酯在常溫常壓下為透明黃色濃稠液體。此系列目標液晶分子均為雙變型液晶,共出現N相、SmA相、SmC相、SmB相及SmX相。10個化合物均具N相,隨烷氧長鏈碳數增加,所呈現之液晶相數目亦隨之增加,且更有利SmC相的形成。N相出現的溫度點隨著長鏈烷氧基碳數增加而出現奇偶效應(odd-even effect)。同時若將聯苯環位置更換為單一苯環則烷氧長鏈為8碳及9碳時,均不具液晶相。
    In 2000 our team have followed the procedures of Gray et.al. to synthesize the compound, benzyl 4-(4'-octoxybiphenyl-4-carbonyloxy) benzoate, and found that it do have mesogenic properties. It exhibits smectic A and smectic C phases. In 2003 two series of new liquid crystals containing cyclohexylmethanol and cyclopentyllmethanol were synthesized. Some of them exhibit a smectic A phase and others possess a smectic C phase.
    A series of liquid crystals containing butoxyacetylphenyl were synthesized and characterized . The compound of terminal group, 1-butyl-4-hydroxyphenylacetate , is a clear pale yellow liquid at room temperature. All the compounds of this series are enantiotropic liquid crystals and exhibit a N phase. Different liquid crystal phases such as nematic, smectic A, smectic C, smectic B and smecticX were observed in these compounds. Smectic C phase can only be formed when the flexible alkoxy chain is longer than n-pentoxyl group. The longer the alkoxy chain is, the more is the number of the liquid crystal phases . The clearing point of nematics decreases when the chain length is increased. An odd-even effect is observed. When the biphenyl ring of compounds 8 and 9 is substituted by the phenyl ring benzyl group , those compounds whose alkyl group is C8 H19 or C9 H19 don't have any liquid crystal phase.
    Appears in Collections:[化學系] 博碩士論文

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