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    Please use this identifier to cite or link to this item: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/51822

    Title: 形成螺旋筒型超分子堆疊之盤狀液晶製備與性質研究
    Other Titles: Preparation and studies of discotic liquid crystals exhibiting helical columnar supramolecular structures
    Authors: 葉懿賢;Yeh, Yi-hsien
    Contributors: 淡江大學化學學系碩士班
    徐秀福;Hsu, Hsiu-fu
    Keywords: 盤狀液晶;筒型;螺旋;螺烯;六苯并蔻;discotic;columnar liquid crystal;helical columnar;helicene
    Date: 2010
    Issue Date: 2010-09-23 16:10:44 (UTC+8)
    Abstract: 本論文以合成可形成螺旋筒型超分子堆疊之盤狀液晶為目的。第一部分合成分子本身具空間螺旋結構之六苯并蔻衍生物,以形成較平面六苯并蔻衍生物更具高秩序性的螺旋筒型超分子結構。第二部分設計單側臂具掌性側鏈之六側臂盤狀液晶分子,經由圓二色光譜儀及掃描式穿隧電流顯微鏡證實掌性側鏈可使其他五個側臂向特定方向偏轉,而形成類風扇葉體構形,使分子堆疊時傾向於同一螺旋方向之螺旋筒柱。更將所設計之掌性化合物摻混至不具掌性化合物中,可由一掌性分子影響其他非掌性分子而形成大範圍之掌性區域,使材料整體顯現掌性特性,而達到大幅放大掌性的功能。
    The goal of this thesis is preparing discotic liquid crystals exhibiting helical columnar supramolecular structures. In the first part, a helicene compound based on hexabenzocoronene (HBC) has been synthesized. Incorporation of the helical conformation onto the HBC has imposed a more ordered intracolumnar molecular packing than the reported planar HBC analogues. In the other part, a series of hexakis(phenylethynyl)benzene derivatives with chiral side-chains have been synthesized and studied. All compounds showed a columnar rectangular liquid crystalline phase within wide temperature ranges by differential scanning calorimetry, polarizing optical microscopy, and powder X-ray diffraction studies. Intramolecularly, the chiral chains of one side-arm have influenced the other five sidearms to induce a helical molecular conformation. Furthermore, intermolecularly, helical columns from propeller-like compounds were generated. Chiroptical studies by circular dichroism (CD) in liquid crystalline phases and scanning tunneling microscopy at liquid-solid interface confirmed intramolecular and intermolecular chiral inductions. Chiral induction by doping a chiral discogen into an achiral analogue was confirmed by increased CD signal intensity upon doping.
    Appears in Collections:[化學學系暨研究所] 學位論文

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