具C3對稱軸的六苯并寇衍生物的製備及液晶性質探討

Synthesis and Properties of Hexabenzocoronene Derivatives with a C3 Rotation Axis

邱奕儒(Yi-Ju Chiu)

指導教授 ： 徐秀福

淡江大學/理學院/化學學系碩士班/碩士(2010年)

https://doi.org/10.6846/TKU.2010.00450

摘要

本論文主要合成盤狀筒型液晶材料，以六苯并寇為中心核設計出具C3對稱軸的六苯并寇衍生物，希望藉由結構的設計達到改善分子排列緊密度的目的。將文獻已發表的六苯并寇衍生物結構做兩種修飾：(一)六苯并寇外圍分別連接兩種不同長度的側鏈，利用長短鏈交錯，達到類似齒輪卡接模式使筒柱間呈最密排列；(二) 在分子核外特定位置引入高電負度的氟原子使芳香分子核間因局部偶極作用力互補對應堆疊，達到筒柱內及筒柱間的高序排列，預期可使電子傳導率提升。合成出的化合物皆具有筒型液晶相，並利用偏光顯微鏡、熱微差掃描儀及粉末X光繞射儀鑑定其性質。引入長短交錯的烷鏈，藉由粉末X光繞射證實，長短鏈的引入雖使分子與分子彼此靠近，但利用Scherrer equation計算筒柱間及筒柱內分子排列延伸性，發現並未較不具長短鏈之文獻化合物佳。而引入氟原子後筒柱間的分子排列延伸長度與引入長短鏈交錯的化合物相同，但筒柱內有較多的盤狀單元延伸。

關鍵字

盤狀筒型液晶 ； 六苯并寇

並列摘要

In the thesis, hexa-peri-hexabenzocoronene-(HBC)-based derivatives of discotic columnar liquid crystal materials with a C3 symmetry were synthesized. HBC-based derivatives were modified via two means of structural design to induce denser molecule stacking. All compounds showed a columnar liquid crystalline phase by differential scanning calorimetry, polarizing optical microscopy, and powder X-ray diffraction studies. First, two different lengths of side-chains were attached onto a hexabenzocoronene to achieve the closest stacking by stagger molecular gears. Powder X-ray diffraction results showed a closer intercolumnar packing; however, the intra- and inter-columnar repeating units calculated by Scherrer equation are of the same order as those of HBC with the same length of alkyl chains. Second, the HBC core was introduced high electronegative fluorine atoms. Complementary intercore interactions by local dipole moment make highly ordered arrangement within column possible. Herein, the correlation length within columns was found to be longer than that of analogous HBC compounds without fluorine atoms.

並列關鍵字

columnar liquid crystal ； hexa-peri-hexabenzocoronene ； C3 rotation axis

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