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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/71290

    Title: 含不對稱多雜環分子之液晶相行為探討
    Authors: 胡倩瑜;Hu,Chien-Yu
    Contributors: 化學學系
    Keywords: 液晶;雜環;liquid crystal;pyrazole;oxadiazole;isoxazole
    Date: 2016-07-13
    Issue Date: 2016-10-13 12:40:34 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 系列一主要是探討含多雜環分子液晶表現,微觀去觀察雜環如何影響液晶行為,成功合成出含有isoxazole、oxadiazole、pyrazole兩兩組合成的不對稱雜環且位相不同之1a、1b;2a、2b; 3a、3b化合物,證實相異雜環對於液晶有極大影響,且分子中間三雜環越趨向線性之結構,其液晶行為表現較佳。透過2b單晶結構,研究雜環可以誘導出何種作用力並模擬出液晶相時排列,利用成功養出的3a單晶結構,得知雜環之間作用力,也進而得知分子形狀會影響液晶表現。
    ;In the first series, for new series of unsymmetric isoxazoles、pyrazoles and 1,3,4-oxadiazoles were prepared, characterized and their mesomorphic properties investigated. Isoxazoles were obtained by condensationcyclization of –diketones with hydroxylamine hydrochloride in refluxing THF,and pyrazoles obtained by condensationcyclization of –diketones with hydrazine in refluxing THF,while 1,3,4-oxadiazoles were obtained from hydrazine–carboxylate in refluxing POCl3.The data indicated that all compounds with meta-substituted benzene1b、3bwere not mesogenic. Interestingly, the other series of compounds with para-substituted benzene1a、2a、3aexhibited N/ SmC /SmA phases. The formation of mesophases in 1a、2a、3a might be attributed to the better linear molecular shapes. In contrast, all compounds 1b、3b were more likely bent-shaped,for mesomorphic.
    In the second series, a system of isoxazole containing function group of hydroxyl, performed reaction of condensation reaction then exhibition mesomorphic properties was synthesize and examined. 4a exhibited SmX/SmC phase. Results indicated that increasing the pryazoles would raise the isotropic temperatures and increasing the OH function group would supply hydrogen bonds for molecular arrangement regularity. These mesomorphic properties were studied and identified by polarization microscopy, differential scanning calorimetry, and X-ray diffraction methods.
    Appears in Collections:[化學研究所] 博碩士論文

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