摘要: | II 中文摘要 系列一:合成出一系列bis-(1,3,4-oxadiazoles)的有機液晶分 子。所得之化合物經由1H- 和13C-NMR 光譜及元素分析(EA)加以鑑定 及結構與純度。而液晶現象的觀察,藉由熱差式掃瞄卡計儀(DSC)和 偏光顯微鏡(POM)來判斷。實驗結果顯示,不論其為meta 位置或para 位置之化合物,當側鏈基數目為6 時,均為Colh液晶相。然而meta 位置之化合物,當側鏈基碳數為8 至16 都是Colh液晶相,且液晶相 溫度範圍較寬廣,流動性也較佳。除了研究液晶相關性質,也做了一 些其他物性之探討。 系列二:合成一系列salicylaldimine 之配位基,此配位基在與 金屬(Pd、Cu)配位,形成錯合物。實驗結果得知,側鏈取代基為拉電 子基且接近苯環,會使液晶相溫度範圍縮短。進而發現,改變中心硬 段部分而合成benzoxazole 之錯合物,當側鏈基含有萘環時,其具有 N 液晶相。 In this work two series of heterocyclic compounds in which two unsaturated five-membered ring based on 1,3,4-oxadiazole utilized as the core center were generated and their mesomorphic properties investigated. Some of this type of oxadiazole-based materials have been studied and found to show novel properties, and these physical studies were focused on electron-transporting capability or photoconducting for advanced electronic devices. However, examples of mesomorphic 1,3,4-oxadiazole derivatives were relatively scarce. 1,3,4-oxadiazole derivatives were though considered as one of non-linear mesogenic compounds. Here we report the first example derived from bis(1,3,4-oxadiazole) that exhibit a columnar phase. Results indicated that all derivatives of 1,4-bis[2-(3,4,5 -trialkoxylphenyl)-1,3,4-oxadiazol-5-yl]benzenes and 1,3-bis[2-(3,4,5 -trialkoxylphenyl)-1,3,4-oxadiazol-5-yl]benzenes were columnar mesophases. |