具有ESIPT與ESDPT性質化合物之合成與研究

第一部分關於具有雙路徑激發態質子轉移的 3-hydroxyflavone 衍生物， 3-hydroxy-2-(pyridin-2-yl)-4H-chromen-4-one, 在其質子轉移機制上所做的研究。雙路徑質子轉移在 3-hydroxyflavone 衍生物中，此分子為首例，透過分子的設計，質子轉移的路徑可以發生在 hydroxyl group 和 pyridinic group 之間或是 hydroxyl group 和 carbonyl group 之間。固態時，由 X-ray 的分析結果可知，僅前者會發生，而在溶液態時，兩個路徑皆可進行，但前者因 pyridinic group 會旋轉而不放光。透過酸鹼控制或保護基的引入﹙於溶液態時﹚，可將 pyridinic group protonate 或 protect 起來，此時質子轉移僅只能發生在 hydroxyl group 和 carbonyl group 之間。雙路徑質子轉移，在經過適當的調控後，可切換回以往的單一路徑，進而在螢光光譜或吸收光譜上呈現出差異。第二部分則是研究激發態質子轉移的反應,其中包括了溶液態的分子間與分子內的質子轉移現象,再研究雙質子轉移的反應我們設計了一個6HIQ與7-azaindole (7AI)分子有非常類似的質子提供與接受團,因此彼此可以互相形成非對稱性的二聚體結構,但6HIQ的可見紫外光吸收比7AI還要再更紅位移100nm左後,因此我們可以選擇性的激發6HIQ分子產生非對稱性的雙質子轉移,來光察到雙質子轉移過程中所存在的中間體,此項發現可以有力的證明在非對稱的雙質子轉移系統,其轉移反應是兩個質子以兩個步驟(two-step)進行的

關鍵字

激發態分子內質子轉移；電荷轉移；質子轉移； 3-羥基黃酮

並列摘要

The dual function of the excited-state intramolecular proton transfer (ESIPT) in the newly synthesized 3-hydroxy-2-(pyridin-2-yl)-4H-chromen-4-one has been recognized. One of the two ESIPT routes typically happens between the hydroxyl group and the carbonyl group in a five-membered ring configuration. The other occurs between the hydroxyl group and the pyridinic group in a six-membered ring configuration. The switchable ESIPT implies the potential applications of the pH fluorescent indicator and the anion chemosensor. The dual function in the 3-hydroxyflavone derivative is believed to further spark large interests for the utilization of the ESIPT in a more practical way. On the other hand, the ESPT dyanmcis via intermolecular hydrogen bonding has also been reviewed. Particually, a four 6HIQ is strategically designed and synthesized; it possesses a central moiety of 7-azaindole (7AI) and undergoes excited-state double proton transfer (ESDPT). Despite a barrierless type of ESDPT in the 6HIQ dimer, femtosecond dynamics and a kinetic isotope effect provide indications for a stepwise ESDPT process in the 6HIQ/7AI heterodimer.

並列關鍵字

ESIPT ； ESDPT ； excited-state intramolecular proton transfer ； 3-hydroxyflavone

參考文獻

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具有ESIPT與ESDPT性質化合物之合成與研究

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