Sudies on Ionic Intermediates by Flash Photolysis

闪速光解法研究离子中间体

• 批准号: 04640498
• 负责人: OKUYAMA Tadashi
• 金额: $ 1.28万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04640498/
• 关键词: Flash photolysis; Laser photolysis; Photoreaction; Radical cation; Carbocation; Electron transfer; Unstable intermediate; 置換基効果

Reactivity of dithiolanylium ions generated by flash photolysisi of 2-methoxy-2-aryl-1,3-dithiolane carrying various ring substituents were examined in aqueous solution. The isolated perchlorate salts of some of these carbocations were also studied for comparison. The substuent effect analyzes according to the Yukawa-Tsuno equation show that the transition state for the hydration of the carbocation is claser to the initial state rather than the product. Photolysis of 2-ethoxy-1,3-dithiolane in the presence of 9-cyanoanthracene (9CA) as an electron acceptor in methanol gave products of ring opening, that may result form the radical cation of the dithiolane.Laser photolysis (YAG, 266 nm) of various 9-alkoxy-9(p-methoxyphenyl)xanthene in aqueous solution whowed formation and decay of the 9-arylxanthenylium ion. The rate of the decay of the cation is dependent on the alkoxyl group, shwing that the decay occurs form the ion pair of the xanthenylium ion and the alkoxide anion.Photolysis of 9-benzylxanfhene in the presence of 9CA resulted in a complex mixture of pfoducts, but its photolysis in aqueous K_2S_2O_8 solution gave xanthone via xanthenol. The laser photolysis of 9-benzylxanthene showed a transient formation of xanthenylium ion. These results show that the raction mechanism involves an electron transfer form the xanthene to SO_<4->・and cleavage to five benxyl radical and xanthenylium ion which is hydrated to xanthenol. The xanthenol formed can rapidly be oxidezed to xanthenone.

在水溶液中检查了由2-甲氧基-2-芳基-1,3-二硫代携带各种环的2-氧基-2-二硫代二硫代二硫代离子的反应性。还研究了其中一些碳聚球的分离的高氯酸盐盐进行比较。根据Yukawa-tsuno方程的微观效应分析表明，碳酸盐水合的过渡状态是将其碎屑到初始状态而不是产物。 2-乙氧基-1,3-二硫代的光解在9-甲烷烃（9CA）的存在下作为甲醇中的电子受体的光解会产生打环的产物，这可能会导致二硫代的激进阳离子的阳离子阳离子。 9-芳基氯苯基离子。阳离子的衰变速率取决于烷氧基群，降低衰变形成了叶丁基离子的离子对和烷氧化物阴离子的离子对。在9CA的存在下，9-CA的9CA的光解会导致其在pfoducts中，但在pfoducts中产生了squos_2s_2s_2s_2s_2s2s_2s2s_2s2s2s_2s2s22s_22黄苯酚。 9-苯乙烯的激光光解会显示出木马离子的瞬时形成。这些结果表明，赛车机制涉及将电子转移形成xanthenylium离子至SO_ <4-> ・，并切割至五个苯甲酰基和黄苯基离子，该离子水合为xanthenol。形成的黄尼酚可以迅速被氧化物氧化为黄褐酮。

项目成果

奥山 格: "Kinetics and mechanism of 2-aryl-1,3-dithiolan-2-ylium ions in aqueous solution" Bull.Chem.Soc.Jpn.67(発表予定). (1994)

Itaru Okuyama：“水溶液中 2-aryl-1,3-dithiolan-2-ylium 离子的动力学和机理”Bull.Chem.Soc.Jpn.67（待提交）。

奥山 格: "Flash Photolytic Generation of a dithio Carbocation from 1,3-Dithiolane Derivatives" Bulletin of the Chemical Society of Japan. 64. 2751-2756 (1992)

Itaru Okuyama：“从 1,3-二硫杂环戊烷衍生物中快速光解生成二硫代碳阳离子”，日本化学会通报 64. 2751-2756 (1992)。

Tadashi Okuyama, Tonoki Takino, Takuya Sueda, and Masahito Ochiai: "Solvolysis of a cyclohexenyliodonium salt. Remakable nucleofuge and return form intimate ion pair" J.Am chem Soc.(in press).

Tadashi Okuyama、Tonoki Takino、Takuy​​a Sueda 和 Masahito Ochiai：“环己基碘鎓盐的溶剂分解。Remakable 离核并返回形成亲密离子对”J.Am chem Soc.（出版中）。

奥山 格: "Solvolysis of a cyclohexenyliodonium salt:Remarkable nucleofuge and return from intimate ion pair" J.Am.Chem.Soc.116(発表予定). (1994)

Itaru Okuyama：“环己基碘鎓盐的溶剂分解：显着的离核和从亲密离子对返回”J.Am.Chem.Soc.116（待提交）。

Tadashi Okuyama and Hitomi Jinsenji: "kinetics and mechanism of 2-aryl-1,3-dithiolan-2-ylium ions in aqueous slution" Bull. chem. Soc. Jpn.(in press).

Tadashi Okuyama 和 Hitomi Jinsenji：“水溶液中 2-芳基-1,3-二硫杂环戊烷-2-基鎓离子的动力学和机理”公牛。