合成及鑑定含烷氧取代基之五個芳香環共軛的螢光材料

Abstract

本研究在於合成及探討含烷氧取代基之五個芳香環共軛的螢光材料。此類化合物及其類似的聚合物以Wittig-Hornor Reaction合成，由共軛及非共軛的柔軟基兩部分構成; 含五個共軛環的寡聚物模型分子(Oligomer model compounds)與其衍生的高分子作一特性的比較。藉由改變在分子長軸末端及側向上的取代基來作結構上修飾，並利用熱微差掃描卡計(DSC)和偏光顯微鏡(POM)做其相關液晶行為的量測。研究發現適當長度的側端和末端長碳鍊有助於液晶相（向列相）的生成，但過長則會使液晶相的範圍縮短。而化合物的光學及電學性質則由紫外光/可見光光譜儀、螢光光譜儀及 電致發光光譜儀量測; 共軛有機分子側端和末端長碳鍊的改變，對螢光體而言並沒有太大的影響。 最後利用具有液晶行為的螢光分子，偵測其在液晶相（nematic）時的螢光特性，證明其在放入平行配向cell中配向後發出的光為偏極光，成功地將液晶相製備出有機發偏極光的特性。

This report is to synthesize and investigate novel photoluminent materials containing five conjugated-rings with alkoxy-substituted side groups. These compounds and analogous polymers containing conjugated and flexible parts are synthesized by Witting-Hohner reaction . These model compounds having five conjugated-rings are compared with the derivative polymers . By modification of the side chains and end groups of the conjugated molecules, we are able to characterize their mesogenic behavior by DSC and POM. The measurements reveal that appropriate lengths of the side chains and end groups result in better liquid crystallinity (the nematic phase); however, the range of the mesogenic phase is reduced at longer lengthsof above chains. The optical and electric properties of the compounds are determined by UV-vis, photoluminescent (PL) and electroluminescent (EL). These measurements reveal that the tuning of side chains and end groups would not affect their fluorescence properties significantly. To conclude this report, we have developed novel fluorescent conjugated compounds possessing mesogenic properties, which can generate polarized light in the aligned nematic phase by using parallel alignment cells. We have succeed in producing polarized photoluminescent cells by application of the liquid crystalline phase.