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    請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/6103


    題名: 以1,3,4-thiadiazole為架構之不對稱無機液晶材料;Synthesis and Characterization of Copper(Ⅱ) Complexes Derived from 1,3,4-Thiadiazole-based Containing Asymmetric Cores
    作者: 廖政宗;Cheng-Tsung Liao
    貢獻者: 化學研究所
    關鍵詞: 液晶;liquid crystal;thiadiazole
    日期: 2005-06-24
    上傳時間: 2009-09-22 10:13:16 (UTC+8)
    出版者: 國立中央大學圖書館
    摘要: 近幾年來含雜環的液晶分子已經被廣泛的研究,而本篇論文系列一設計並合成含thiadiazole之不對稱的配位基及其相對應金屬錯合物,系列二則為含Benzoxazole之對稱二聚物結構。本實驗所合成之化合物皆由1H與13C-NMR光譜及元素分析(EA)來鑑定分子的結構與純度,液晶相性質由偏光顯微鏡來觀察偏光紋理圖,再以熱差式掃描卡計儀測定相變化,最後以變溫粉末X-ray繞射鑑定其液晶相的結構。 系列一的實驗結果顯示配位基與錯合物皆呈現了桿狀的液晶相,其液晶相為N、SmA與SmC,可以發現這些化合物的液晶相性質跟侧鏈基的碳鏈長短有關,隨著碳鏈的減少澄清點與熔點的溫度增加,另外錯合物的澄清點明顯比配位基來的高許多。 系列二的實驗結果顯示了所有的化合物皆為規則度較好的SmC相,且當固定中間橋接基時,隨著側鏈基碳鏈增加澄清點溫度相上升,而令人值得注意的是此系列的分子有明顯的奇偶效應。 The design and synthesis of liquid crystals (LCs) containing heterocyclic units have been the subject of much research in recent years. Series Ⅰ: design and synthesis of Copper(Ⅱ) complexes derived from 1,3,4- thiadiazole-based containing asymmetric cores. Series Ⅱ: a novel system of symmetric dimmer liquid crystals containing benzoxazole units. All compounds were all characterized by 1H and 13C-NMR spectroscopy , their mesomorphic properties were studied by differential scanning calorimeter (DSC) ,polarized optical microscopy (POM) and temperature dependent powder X-ray diffraction. Experimental data indicated that series Ⅰ, all compounds exhibited, nematic(N), smectic A (SmA) and/or smectic C (SmC) phases, as expected by rod-like molecules. In addition, the mesomorphic properties observed by these compounds were found to be strongly dependent on the carbon chain length of terminal side chains. Both the melting and clearing points were increased with decreasing the carbon chain length. The transition temperatures of these rod-like metallo- mesogens are higher than those of the corresponding metal-free ligands. In the series Ⅱ, all compounds exhibited smectic C (SmC) phase, and when we fix the carbon number of the spacer, clearing points increased with increasing the carbon number of side chain. Odd-even effect could also be observed obviously in series Ⅱ.
    顯示於類別:[化學研究所] 博碩士論文

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