盤狀分子引入單一氟原子與具掌性側鏈室溫液晶分子排列之探討

Investingation of mesogenic properties on introduing dipole onto disc-shaped molecules based on pentaphenynylbenzenes with chiral side arms

黃苑榕(Yuan-Jung Huang)

指導教授 ： 徐秀福

淡江大學/理學院/化學學系碩士班/碩士(2015年)

https://doi.org/10.6846/TKU.2015.00809

摘要

本論文以盤型液晶分子為主架構，一部分以六炔苯基苯中引入高電負度之氟原子與掌性側鏈，利用分子間的氫鍵與掌性側鏈的緊密排列，產生堆疊整齊之筒形液晶，在不失去液晶分子的特性，再修飾不同位置與不同數目之氟原子，進而提升澄清點與降低熔點，可達到寬廣的液晶溫度範圍。另一部分以五炔苯基苯中引入不同鹵素，其凡德瓦半徑越小，分子在室溫成液相，反之則形成液晶相；在第六位置引入鄰氟苯烷氧鏈，因比前一部分氟原子數目的減少，進而氫鍵減弱，使其呈盤形向列型液晶。

關鍵字

六炔苯基苯 ； 盤型液晶 ； 膽固醇液晶

並列摘要

In the study, fluorine atoms with high electronegativity and the chiral side chain were introduced onto hexa(difluoroalkoxyphenyl)benzenes to show columnar liquid crystal phase due to hydrogen bonding and the close packing of chiral chain. The melting point lowerd and clearling points raised by modifying fluorine atoms with different numbers and positions. On the other part, different halogen atoms were induced on 1,2,3,4,5-pentaylpentakis(ethyne-2,1-diyl))pentabenzene. The clearing point increased with larger van der waals radius of halogen atom. The compound which was introduced one 2-fluoro-4-alkoxychainbenzene exhibited discotic nematic liquid crystal phase due to the weak hydrogen bonding from smaller numbers of fluorine atoms.

並列關鍵字

hexa(difluoroalkoxyphenyl)benzenes ； discotic nematic

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