具有Quinoxaline結構之雙金屬無機液晶材料

Columnar Bimetallomesogens: Copper Complexes Derived from Quinoxaline Ring

吳宇哲(Yu-Che Wu)

指導教授 ： 賴重光

國立中央大學/理學院/化學系/碩士(2006年)

摘要

系列一為具有quinoxaline結構之無機液晶，此系列以化合物2 2,3-bis(3.4-dialkoxylphenyl)quinoxaline-6-carboxylic-[(2-hydroxy-4-alkoxylphenylimino)methyl]-phenyl esters為配位基，與過渡金屬銅、鋅及鈀配位形成無機液晶，所得之化合物皆以1H、13C-NMR及元素分析鑑定，並以DSC、偏光顯微鏡及POWDER X-RAY鑑定其液晶相。
錯合物形成具有8-10根側鏈基之雙金屬盤狀液晶，其中銅及鈀錯合物具有寬廣液晶範圍，在液晶相時形成hexagonal columnar phases (Colh)相，結構為型變平面四邊形配位；鋅錯合物則不具有液晶相產生。

系列二為具有benzoxazole 及quinoxaline 結構之有機分子，經由DSC、偏光顯微鏡及POWDER X-RAY鑑定後可以得知，化合物在液晶相時形成hexagonal columnar phases (Colh)盤狀液晶，其發光性質亦利用UV-Vis及螢光光譜鑑定，化合物之螢光發光來源為quinoxaline環，量子產率約為26 %。

系列三中合成並比較4種含benzylidene-aniline及quinoxaline環結構有機液晶分子，化合物在液晶相時形成hexagonal columnar phases (Colh)盤狀液晶，且可以發現化合物的澄清點溫度、液晶相時的排列、發光性質皆受到取代基的影響。

關鍵字

盤狀液晶 ； 液晶 ； 無機液晶

並列摘要

In this thesis, we report the synthesis, characterization and mesomorphic properties of new mesogenic derivatives based on quinoxaline structure.

In series one , A new type of binuclear transition metal complexes derived from 2,3-bis(3.4-dialkoxylphenyl)quinoxaline-6-carboxylic-[(2 -hydrox y-4-alkoxylphenylimino)methyl]-phenyl esters was prepared and characterized. The mesomorphic properties of these copper comple -xes of were studied by differential scanning calorimetry (DSC) and polarized optical microscope (POM). These complexes have two metal centers as core group and have totally eight or ten alkoxy side chains appended around the central core forming a columnar molecule. All derivatives of copper(II) and palladium(II) compounds exhibited columnar mesophases over a wide range of temperatures. The geometries at metal centers is distorted square planar. The mesophases were identified as hexagonal columnar phases (Colh) based on the optical textures. Zinc(II) compounds don’t exhibited columnar mesophases.

In series two, we designed and characterized a series of new type of organic molecule derived from benzoxazole and quinoxaline rings with totally five side chains. Their mesomorphic properties were studied by differential scanning calorimeter (DSC) ,polarized optical microscopy (POM) and temperature dependent powder X-ray diffraction. Compounds exhibited columnar mesophases over a wide range of temperatures. Their luminescence properties were also studied by UV-Vis and fluorescence spectrometry. We found that fluorescent properties come form quinoxaline rings with Quantum yield about 26%.

In series three, we designed and characterized four kind of organic molecule derived from benzylidene-aniline and quinoxaline rings with totally five side chains. Their mesomorphic properties were studied by differential scanning calorimeter (DSC) ,polarized optical microscopy (POM) and temperature dependent powder X-ray diffraction. Compounds exhibited columnar mesophases over a wide range of temperatures. The clearing point, arrangement in mesophase, luminescence properties were found to be strongly dependent on the hydroxy group attached.

並列關鍵字

metallomesogens ； discotic liquid crystals ； liquid crystals

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