| 摘要: | 離子液晶其性質相較於傳統有機分子為極大不同，它們是由有機離子所組成，而有機結構具有無限變化意喻其為「可設計化」或「可微調化」，故離子液晶本於其獨特性質可以結合液晶(例如分子自組裝、非等向性等物理性質)與離子液體(例如離子導電性及其他等等)在近廿年來引起了相當大關注，而未來必定也預期將有爆炸性發展。
雖然第一個離子液晶即為吡啶鹽早於1938年就發表，近廿年來氮原子基礎的離子液晶研究有銨鹽、咪唑鹽、吡咯鹽、哌啶鹽、哌嗪鹽、嗎啉鹽及吡啶鹽等依然熱烈，而吡啶鹽的研究多為烷基取代吡啶鹽，雖然得知有芳香基取代可以對液晶原穩固性有幫助，但其他研究之芳香基都非取代於氮原子上。本研究以Zincke反應合成出N-芳香基取代吡啶氯鹽，然後使用甲醇為相轉移溶劑之技巧並利用皮爾森之軟硬酸鹼理論，將此吡啶氯鹽置換其他軟性陰離子對，而對此系列物質作其液晶性質之研究。
除了單鏈線形單離子吡啶鹽系列物質之液晶性質之研究外，我們亦對三鏈扇形單離子吡啶鹽系列物質，甚至於單鏈線形及三鏈扇形雙離子聯吡啶鹽系列物質進行研究。此外，我們亦對於陰離子誘導液晶性質，包括單鏈線形及三鏈扇形相對陰離子的吡啶鹽系列物質進行探討。
;Ionic liquid crystals (ILCs) are entirely different properties from those of ordinary organic molecular compounds. They are composed of organic ions, and these organic compounds have unlimited structural variations which are “designable” or “fine-tunable”. Because ILCs’ unique properties that combine the characteristics of liquid crystals (i.e., self-assembling, anisotropic properties, etc.) with those of ionic liquids (i.e., ionic conductivities, and so forth) have been of great interest during the last two decades, we can expect explosive development in the future.
Although the first ILCs being pyridinium salts were reported in 1938, recently the fields of N-based ionic liquid crystals (i.e., Ammonium, Imidazolium, Pyrrolidinium, Piperidinium, Piperazinium, Morpholinium and Pyridinium cations) were also described with increasing interest. About pyridinium-based ILCs, many works are focusing on N-alkylpyridinium salts. Further the aryl- substituted pyridinium cations can make the rigid mesogens found in some works, but N-aryl substituents. So we synthesized the N-arylpyridinium chlorides via Zincke reaction. And we using methanol as a phase-transfer solvent replace the chloride anion into another soft anion by Pearson’s HSAB theory. Then we will describe that ILCs’ characteristics of these type substituents.
In addition to those N-(mono-alkoxyaryl)-pyridinium salts of linear mesogens, we made N-(tri-alkoxyaryl)-pyridinium salts of tapered mesogens, N-(mono- alkoxyaryl)-bipyridinium salts of linear mesogens, and N-(tri-alkoxyaryl)- bipyridinium salts of fan-shaped mesogens. Furthermore, we also concerned about the anion-induced mesogens of pyridinium salts. |
