Design of Reactivity of Organic Cation Radicals Generated by Photoinduced Electron Transfer

光致电子转移产生的有机阳离子自由基的反应性设计

• 批准号: 06640708
• 负责人: AKABA Ryoichi
• 金额: $ 1.34万
• 依托单位: Gunma College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640708/
• 关键词: Cation Radical; Photoinduced Electron Transfer; 2, 4, 6-Triphenylpyrylium Salt; Oxygenation; C-C Bond Cleavage; Deprotonation; Olefin Cation Radical; Laser Flash Photolysis; 光電子移動反応

The present study deals with the design of reactivity of organic cation radicals generated by photosensitized electron transfer in solution. The sensitizers employed are 2, 4, 6-triphenylpyrylium salt (TPP), 2, 4, 6-triphenylthiapyrylium salt (STPP), and 9, 10-dicyanoanthracene (DCA) 1. Firstly, cation radicals of diarylethanals were generated by TPP, STPP and/or DCA, and the products were compared. Laser flash photolysis has also been carried out to elucidate the reactive intermediates involved. The results suggest that the reacivity of diarylethanal having 4, 4-dimethoxy groups in the presence of oxygen is quite different between DCA and TPP sensitized reactions.2. Secondary, tetrakis (4-methylphenyl) ethanone was investigated with DCA and TPP as sensitizers, and it was found that the C-C bond cleavage occurred in both reactions with different mechanisms for the product formation of same kinds.3. Thirdly, Deprotonation of 9, 10-dihydroanthracene was studied in the presence of oxygen with DCA and TPP sensitization. We have found that TPP sensitized oxygenation gave anthracene whereas DCA sensitization gave anthrone as a primary, major product. The results were interpreted in terms of the acidity of superoxide radical anion (O_2^-.) involved in DCA sensitized oxygenation, which is absent in the TPP sensitized oxygenation. 4. Lastly, TPP and DCA sensitized oxygenation were carried out for stilbene (ST), triphenylethylene (TPE), and tetraphenylethylene (TEPE), and comparison of products revealed that TEPE does not react with molecular oxygen while ST and TPE react. All olefins studied were found to react with O_2^-. The observed difference of reactivity of olefin cation radicals were discussed in terms of stability of intermediate peroxy radical cations and dioxetane cation radicals.

本文研究了光敏电子转移在溶液中产生的有机阳离子自由基的反应性设计。采用的增敏剂有2,4,6 -三苯基吡啶盐（TPP）、2,4,6 -三苯基噻吩盐（STPP）和9,10 -二氰蒽（DCA） 1。首先，对TPP、STPP和/或DCA生成的二芳醛的阳离子自由基进行了比较。还进行了激光闪光光解以阐明所涉及的反应中间体。结果表明，具有4,4 -二甲氧基的二乙基乙醛在氧存在下的反应性在DCA和TPP增敏反应中有很大差异。其次，以DCA和TPP为增敏剂对四（4-甲基苯基）乙酮进行了研究，发现两种反应的C-C键裂解机制不同，形成了同类产物。再次，用DCA和TPP增敏法研究了9,10 -二氢蒽在氧存在下的去质子化反应。我们发现TPP增敏的氧化产生蒽，而DCA增敏的主要产物是蒽酮。结果可以用DCA敏化氧化过程中参与的超氧阴离子（O_2^-）的酸度来解释，而TPP敏化氧化过程中没有。4. 最后，对二苯乙烯（ST）、三苯基乙烯（TPE）和四苯基乙烯（TEPE）进行了TPP和DCA增敏氧化，产物比较表明，TEPE与分子氧不发生反应，而ST和TPE发生反应。所有的烯烃都能与O_2^-反应。从中间过氧自由基和二氧乙烷阳离子自由基的稳定性方面讨论了烯烃阳离子自由基反应性的差异。

项目成果

R.Akaba et al.,: "Evidence for Proton Transfev in Radical Ion Pairs." J.Chem.SOL.,Chem.Commun.,に投稿予定.

R.Akaba 等人：“自由基离子对中质子传递的证据”将提交给 J.Chem.SOL.、Chem.Commun.。

R. Akaba et al.,: "Deprotonation of Drganit Radical Cations, Evidence for" J. Phys. Org. Chem.,. (印刷中). (1996)

R. Akaba 等人，“Drganit 自由基阳离子的去质子化，证据”J. Phys.，（出版中）。

R. Akaba et al. ,: "Deprotonation of Organic Radical Cations. Chemical Evidence for Proton Transfer between 9, 10-Dihydroanthracene Radical Cations and Superoxide Radical Anions" Journal of Physical Organic Chemistry. (1996)

R.阿卡巴等人。

Ryoichi, Akaba Mitsuru, Iwasaki Tsuyoshi, Matsumura Masaki, Kamata Hiroki, Itoh: "Deprotonation of Organic Radical Cations. Chemical Evidence for Proton Transfer between 9, 10-Dihydroanthracene Radical Cations and Superoxide Radical Anions" Journal of Phy

Ryoichi、Akaba Mitsuru、Iwasaki Tsuyoshi、Matsumura Masaki、Kamata Hiroki、Itoh：“有机自由基阳离子的去质子化。9, 10-二氢蒽自由基阳离子和超氧自由基阴离子之间质子转移的化学证据” Phy 杂志

R. Akaba et al.,: "C-H Bond Cleavage of Organic Radical Cations." J. Am. Chem. Sol.,. (投稿予定).

R. Akaba 等人：“有机自由基阳离子的 C-H 键裂解”。