藉由具有質子之離子液體當催化劑改良含氧多環芳香碳氫化合物的合成與其性質之研究

Synthesis, Properties Of Oxygen-Containing Polycyclic Aromatic Hydrocarbons By Protic Ionic Liquid Catalyst

林義欽(Yi-Chin Lin)

指導教授 ： 劉陵崗

國立中正大學/理學院/化學暨生物化學系/碩士(2012年)

摘要

分子的發光基團決定了其本身的顏色，意即吸收特定紫外-可見光波段和使互補波段透射或反射。在本論文中，我們關注的是π-共軛多環芳香系統中，具有異原子架構的發光基團。
多環芳香碳氫化合物 (PAHs)，可以把它看成是石墨的一個小單位，能利用在各種不同的有機電子元件上。PAHs的芳香環上含有氮或氧異原子,且擁有特殊的化學或物理性質。在過去幾年中含氧原子的benzo[5,6]naphthaceno[1,12,11,10-jklmna]xanthylium (BNAX) 鹽類化合物成功的被合成出來。這些帶正電的PAHs具有優良的紫外-可見光區的吸收峰，並從其放光可看出有很高的量子產率。這類具有正電荷、分子體積巨大且含氧原子的PAHs至今還沒經過更深入的研究。
製備鹽類化合物BNAX還只是初步階段，整個過程還未能達到量產及最佳化。目前主要關注在改進多步的合成步驟及衍生物的製備。目前依據文獻製備化合物BNAX是從Claisen縮合反應，再經過氧化反應，最後是照光合環反應。而把具有拉電子或吸電子性質的官能基取代合成到PAHs上，將有助於了解具有何種性質的官能基會使各種PAH發光基團的光化學與光物理性質作何改變。
在本論文中，我們採用具有質子酸性的離子液體無溶劑系統，來替代強酸混合弱酸的反應系統，進行Claisen縮合反應；離子液體不僅能重複使用，產率也有所提昇。在照光合環反應的步驟中，我們藉由通入氧氣，大幅縮短反應的時間。從單晶X光、粒徑分析，與廷得耳效應等數據結果中，可以觀察到化合物BNAX的分子間作用力和聚集行為。

關鍵字

多環芳香碳氫化合物

並列摘要

A chomophore is the part of a molecule responsible for its color, i.e., absorbing certain UV-Vis wavelengths and transmitting or reflecting the complimentary wavelengths. In this dissertation, the chromophore of interest has a π-conjugated polycyclic aromatic system with heteroatoms in skeleton.
Large polycyclic aromatic hydrocarbons (PAHs), as subunits of graphene, have been exploited in various organic electronic devices. PAHs containing N or O heteroatoms in the aromatic framework exhibit unprecedented chemical and physical properties. Only very recently it became possible for the synthesis of salts of the O-containing benzo[5,6]naphthaceno[1,12,11,10-jklmna]xanthylium (BNAX). These positively charged PAHs exhibit nice UV-Vis absorption bands and are capable of emission with high quantum yields. They are presently also among the positively charged, large in size, O-containing PAHs that are yet to explore.
As preparation of BNAX salts is still at their infant stages, the whole process has not yet been scaled nor operationally optimized. The proposal herein is mainly concerned with the improvement of multiple stage synthesis and the preparation of derivatives. Currently the literature synthesis of BNAX starts with Claisen condensation, followed by oxidization and finalized with photocyclization. Substitution on PAHs with electron releasing or electron withdrawing groups will be synthesized to see what extent functional groups affect the photochemical and photophysical properties on PAH chromophores.
In this dissertation, we used the protic ionic liquid as catalyst under solvent-free condition to replace the mixed strong acid weak acid system to do the Claisen condensation. The ionic liquid route not only increases the yield, but also serves as recoverable and reusable catalyst. Under an oxygen atmosphere, the photocyclization step has been significantly cut short on the reaction time. From the results of single crystal X-ray diffraction, particle size analysis, and Tyndall effect data, we have indeed observed intermolecular interactions and aggregation behavior of BNAX and derivatives.

並列關鍵字

polycyclic aromatic hydrocarbons

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