第一部分：2,6-雙氮雜吲哚與2,6-雙氮雜色胺酸在水溶液中的激發態三質子轉移反應之合成與研究 第二部分：利用熱活化延遲螢光分子於能量儲存系統之設計與研究

Part 1: Synthesis and Study of The Excited-State Triple Proton Transfer Reaction of 2,6-Diazaindoles and 2,6-Diazatryptophan in Aqueous Solution. Part 2: Design and Study of Exploiting Thermally Activated Delayed Fluorescence (TADF) Molecules in Energy Storage.

陳奕涵(I-Han Chen)

指導教授 ： 周必泰

國立臺灣大學/理學院/化學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201702404

摘要

第一部分2,6-雙氮雜吲哚與2,6-雙氮雜色胺酸在水溶液中的激發態三質子轉移反應之合成與研究

我們策略性地設計與合成3-甲基-2,6-雙氮雜吲哚((2,6-aza)Ind) 來探測水溶液中，由水分子催化的激發態質子轉移。一但經電子激發時(λmax ∼ 300 nm) ，(2,6-aza)Ind)在中性水中歷經N (1) –H 到N (6)長距離的質子轉移，產生正常的放光(340 nm)和質子轉移互變異構物的放光(480 nm)，總量子產率為0.25。經由水催化的質子轉移速率顯示顯著的氫/氘動力學同位素效應，在水中的質子轉移速率為8.3 × 108 s−1 而在重水中則是4.7 × 108 s−1。由質子清單(Proton inventory)實驗指出(2,6-aza)Ind)涉及兩個水分子與三個質子的參與，其以一致的、異步的形式進行激發態三質子轉移(ESTPT)。此研究結果第一次展示了氮雜吲哚在純水中三質子轉移的基本原理，且為2,6-雙氮雜色胺酸打下了基礎，2,6-雙氮雜色胺酸是色胺酸的類似物具有和(2,6-aza)Ind)相似的三質子轉移特性，可用於探測蛋白質中的微水環境。

第二部分利用熱活化延遲螢光分子於能量儲存系統之設計與研究

分子太陽能熱能儲存系統是基於將太陽能可逆地轉換成化學能的分子開關。其中，降冰片二烯(NBD)-四環庚烷(QC)系統最被廣為研究。在此篇論文，我們將熱活化延遲螢光材料(TADF)與降冰片二烯(NBD)-四環庚烷(QC)系統結合在一起。我們策略性地設計與合成PXZ-NBD 作為新型且高效的能量儲存感光劑，其以PXZ-TRZ 基團作為TADF 的核心。PXZ-NBD 分子的吸收光譜位於太陽光的範圍(~460 奈米)。而當照射時間增加，放光光譜會隨之改變，是由於降冰片二烯(NBD)的三重態能量與PXZ-TRZ 的三重態能量接近，所以如果我們用紫外光/可見光照射PXZ-NBD，能量可以從PXZ-TRZ 基團傳到NBD，然後儲存能量於QC。PXZ-QC每莫耳可儲存的熱能為177 千焦耳，且於25℃下PXZ-QC 的半衰期為55 天。

關鍵字

質子轉移 ； 激發態三質子轉移 ； 能量儲存 ； 熱活化延遲螢光

並列摘要

Part 1 Synthesis and Study of The Excited-State Triple Proton Transfer Reaction of 2,6-Diazaindoles and 2,6-Diazatryptophan in Aqueous Solution.

3-Me-2,6-diazaindole ((2,6-aza)Ind) was strategically designed and synthesized to probe water molecule catalyzed excited-state proton transfer in aqueous solution. Upon electronic excitation (λmax ∼ 300 nm), (2,6-aza)Ind undergoes N(1)−H to N(6)long-distance proton transfer in neutral H2O, resulting in normal (340 nm) and proton-transfer tautomer (480 nm) emissions with an overall quantum yield of 0.25. The rate of the water-catalyzed proton transfer shows a prominent H/D kinetic isotope effect, which is determined to be 8.3 × 108 s−1 and 4.7 × 108 s−1 in H2O and D2O, respectively. Proton inventory experiments indicate the involvement of two water molecules and three protons, which undergo a relay type of excited-state triple proton transfer (ESTPT) in a concerted, asynchronous manner. The results demonstrate for the first time the fundamental of triple proton transfer in pure water for azaindoles as well as pave a new avenue for 2,6-diazatryptophan, an analogue of tryptophan exhibiting a similar ESTPT property with (2,6-aza)Ind, to probe biowaters in proteins.

Part 2 Design and Study of Exploiting Thermally Activated Delayed Fluorescence (TADF) Molecules in Energy Storage.

Molecular solar thermal (MOST) energy storage systems are based on molecular switches that convert resistant convert solar energy into chemical energy. In MOST energy storage systems, the norbornadiene (NBD) -quadricyclane(QC) system was most widely studied. Herein, we linked the thermal activated delayed fluorescence (TADF) materials with NBD– QC system. PXZ-NBD was strategically designed and synthesized as the new novel, efficient energy storage sensitizer contain a Thermally
Activated Delayed Fluorescence (TADF) core (phenoxazine–
2,4,6-triphenyl-1,3,5-triazine (PXZ-TRZ) ). The molecular PXZ-NBD had an optimized absorption spectrum (onset ~ 460 nm) with respect to the solar emission spectrum to achieve maximal efficiency. Then, the emission would be changed when the irradiated time increase, it was due to the NBD triplet state energy was near the TADF core triplet state energy, so when the UV/Vis light irradiated, the energy transferred from PXZ-TRZ core to the NBD site then to storage the energy. The quantitative
photo-thermal conversion between the PXZ-NBD and PXZ-QC with high energy storage densities 177 kJ/mol, and the half-life of the photoisomer is 55 days in 25℃.

並列關鍵字

Excited State Triple Proton Transfer ； Energy Storage ； Thermally Activated Delayed Fluorescence

參考文獻

Chapter 1 Synthesis and Study of The Excited-State Triple Proton Transfer Reaction of 2,6-Diazaindoles and 2,6-Diazatryptophan in Aqueous Solution.

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