理學院: 化學研究所指導教授: 楊吉水洪雋為Hong, Jyun-WeiJyun-WeiHong2017-03-022018-07-102017-03-022018-07-102016http://ntur.lib.ntu.edu.tw//handle/246246/271958由於剛硬性二苯乙烯 (stiff stilbene) 具有高效率的光異構化性質以及烷基架橋所賦予的剛硬結構特性，使剛硬性二苯乙烯及其衍伸物被廣泛地運用在光驅動的分子開關或者需要高度結構限制的分子結構中。也因為剛硬性二苯乙烯光異構化現象顯著，使其為螢光性質非常微弱的分子；近十年以來，間位胺基效應被發現可成功的讓二苯乙烯分子獲得明顯的螢光提升，因間位胺基效應是否也能在剛硬性二苯乙烯上達到螢光上升的結果是我們非常感興趣的，除此之外，目前針對剛硬性二苯乙烯的光物理行為並沒有密切的研究，所以本論文利用在剛硬性二苯乙烯的間位加上N, N-二甲基胺基，除了探討間位胺基對於剛硬性二苯乙烯的影響外，也希望能藉由探討取代基效應，能夠對剛硬性二苯乙烯的光物理行為有更進一步的瞭解。本論文針對剛硬性二苯乙烯的兩個間位及順式與反式異構物做個別的探討，設計以下分子t-mASS1、c-mASS1、t-mASS2與c-mASS2，由X-ray晶體結構顯示，t-mASS1與t-mASS2的胺基分別為平面與扭曲結構，混成軌域的不同，使間位胺基效應於兩分子有明顯不同的影響力，於正己烷的螢光量子產率 (Φf) 分別為0.73與0.02。由於順式異構物的結構較扭曲，螢光相對較弱，c-mASS1與c-mASS2於正己烷的螢光量子產率分別為0.21與0.01。此外，順式二苯乙烯因光環化作用的影響，其衍生物普遍被認為屬低螢光性質，但c-mASS1於乙腈的螢光量子產率卻可達0.47。Because of the high efficiency in photoisomerization, stiff stilbene derivatives have been employed as photoswitches and sterically restricted substrates. As a result of efficient photoisomerization, stiff stilbenes are low fluorescent chromophores. Regarding the significant meta-amino effect on fluorescence enhancement of trans stilbene, we are interested in the fluorescence properties of stiff stilbene containing N, N-dimethylamino substituent at the meta positions. In this context, meta-amino stiff stilbenes are investigated. To have a full understanding of positional and cis/trans isomers, we designed four molecules, t-mASS1、c-mASS1、t-mASS2 and c-mASS2, for comparison. According to the crystal structures of t-mASS1 and t-mASS2, the N, N-dimethylamino group is planar in the former but twisted in the latter compound, leading to distinct meta amino effect. The fluorescence quantum yields (Φf) in n-hexane are 0.73 and 0.01 for t-mASS1 and t-mASS2, respectively. In addition, the fluorescence is lower for the cis than the trans isomers, partly due to the photocyclization ability. The Φf values of c-mASS1 and c-mASS2 in n-hexane are 0.21 and 0.01, respectively. An unusually high Φf (0.47) was observed for c-mASS1 in acetonitrile.10798345 bytesapplication/pdf論文公開時間: 2019/8/24論文使用權限: 同意有償授權(權利金給回饋本人)螢光剛硬性二苯乙烯光物理fluorescencestiff stilbenephotophysicsthesis10.6342/NTU201602170http://ntur.lib.ntu.edu.tw/bitstream/246246/271958/1/ntu-105-R03223149-1.pdf