第一部份，以二級胺(或烯胺)、酮類與四羥基香豆素為起始物，利用假性四組成(或三組成)反應得到哌喃稠合香豆素之雜環化合物，並經由單晶確定其結構，接著探討其潛在之分子開關性質。 第二部份，合成 3-benzoyl-4-benzylamino-7-dimethylaminocoumarin 化合物並利用單晶與氫光譜圖探討其固態下與溶液下之分子的構型。結果發現此化合物在固態下主要構型以- aromatic stacking為主；溶液下則以分子內氫鍵為主。改變其分子內周圍不同取代來證明分子內兩個苯環的堆疊效應是具有相當敏感度。在光化學探討方面，經由照射紫外光照射下不需加入光敏感試劑即可將7號位置上的二甲基胺會被氧化成醯胺類化合物並且推論其反應機構。最後將分子重新設計後得香豆素與吡咯稠和雜環化合物並探討其氧化還原開關與電致變色性質。其氧化還原開關再氧化是利用紫外光照光利用空氣中的氧氧化，還原則是利用氫化反應，並有顏色與螢光變化做為兩個容易觀察之輸出性質。 In part one, an efficient base-mediated three-component reaction of 4-hydroxycoumarin, acetone, and amine (or enamine) for the synthesis of various substituted pyranocoumarins was described. This methodology was further applied to the design and synthesis of a potential thermochromic colorant. In part two, 3-benzoyl-4-benzylamino-7-dimethylaminocoumarin was synthesized and its conformation in solid state and solution was determined. While the X-ray crystal analysis showed an aromatic - stacking interaction in solid state, the proton NMR studies suggested the presence of an intramolecular hydrogen bonding in solution. Adjacent functional group modifications through N-methylation, reduction of carbonyl group, or replacing the coumarin moiety to dimedone, all resulted in disrupting the - aromatic stacking conformation. Upon UV irradiation, the 7-methylamino group can be oxidized by molecular oxygen to the corresponding formamide in the absence of any external photosensitizers. Further, two coumarin/pyrrole-fused heterocycles were synthesized to explore their photochemical and redox-switching properties. Photooxidation of the prepared colorless pyrrolocoumarin resulted in a distinct change to red and a sharp decrease in fluorescence intensity. The photooxidized product can be swiftly reverted to the original form by either NaCNBH3 reduction or hydrogenation.
