INVESTIGATION ON FORMATION AND CHARACTERISTIC REACTIONS OF DISTONIC CATION RADICALS

双色阳离子自由基的形成及特征反应研究

• 批准号: 13640537
• 负责人: KAWAMURA Yasuhiko
• 金额: $ 2.24万
• 依托单位: The University of Tokushima
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640537/
• 关键词: DISTONIC CATION RADICAL; 1,1-DIARYLETHENES; BENZOPHENONE OXIME ETHERS; PHOTOINDUCED ELECTRON TRANSFER; ONE-WAY GEOMETRICAL ISOMERIZATION; TWO-WAY GEOMETRICAL ISOMERIZATION; OXIDATIVE DECOMPOSITION; STERICALLY CONTROLLED REACTIONS; 1,1-ジアリールエテン; 水

Upon irradiation of 9, 10-dicyanoanthracene (DCA) contained in oxygen-saturated acetonitrile solution of unsymmetrically substituted benzophenone oxime O-methyl ethers, gave rise to the formation of one geometrical isomer around the C=N double bond. Considering the presence of a 1 to 1 mixture of the isomers in the starting material, the phenomenon is quite noteworthy. The same type of the reaction was also observed in the case of the corresponding olefinic compounds. On the basis of some controlled experiments, a superoxide radical is supposed to play a crucial role to show such an unprecedented photoisomerization. In line with the product study, we have performed the molecular orbital calculations to survey most plausible intermediate in the reaction. As a result, the requirements for leading the so-called one-way isomerization of the unsymmetrically 1, 1-disubstituted double bonds are as follows : (1) the presence of an aryl group having a strong electron-donating nature, (2) the pr … More esence of a sterically bulky group at the 2-position, and (3) the presence of another aryl group having a tendency of stabilization due to the formation of a benzylic radical. Computer simulations suggested to be a distonic cation radical as the most plausible intermediate for the reaction. Once a single electron transfer occurred between a photoexcited DCA and the substances, the ion radicals are formed. The resulting DCA anion radical reacted with oxygen to be transformed to a neutral DCA and superoxide. Meanwhile, the starting olefinic compound is altered to the corresponding cation radical. Since the cation radical has a distonic nature, the structure is a geometrically unsymmetrical one of which a cationic part is delocalized in the molecular framework consisted with the aryl group and the double bond. In the cation radical, the radical part is only delocalized at another vertically standing aryl group against the rest of the molecular framework. The superoxide reacted with the double bond and when it forms the dioxetane-like molecules, the recipient double bond cannot help rotating the predetermined direction owing to the presence of the vertically standing benzylic radical moiety. Mechanistic details and other reactions of the relevant diatonic cation radicals have been also studied Less

辐射后，在氧气饱和的乙腈溶液中包含的9二烷烷烃（DCA）的辐射后，未取代的苯二苯甲酸氧甲基O-甲基乙基溶液中，含有氧气的O-甲基乙醇，从而形成了C = N双键周围的一个几何异构体。考虑到起始材料中异构体的1-1混合物的存在，这一现象非常值得注意。在相应的烯烃化合物的情况下，还观察到了相同类型的反应。在一些受控的实验的基础上，预期超氧化物自由基发挥了至关重要的作用，以表现出这种前所未有的光异构化。根据产品研究，我们进行了分子轨道计算，以调查反应中最合理的中间体。结果，领导不对称的1个，1-脱亚成双键的所谓单向单向异构化的要求如下：（1）存在具有强烈电子的芳基群的存在，（2）在2位处的较大群体的较大群体，以及（3）在2位且（3）具有另一个质子的趋势的趋势，以及（3）具有较大的属性。 激进的。计算机模拟认为是反应的最合理的中间体是一种疏远的阳离子自由基。一旦将单个电子转移到光激发DCA和物质之间，就会形成离子自由基。所得的DCA阴离子与氧气反应，转化为中性DCA和超氧化物。平均值，将起始烯烃化合物变为相应的阳离子自由基。由于阳离子自由基具有独特的性质，因此该结构是几何不对称的，其中阳离子部分在分子框架中被定位于芳基框架和双键。在阳离子自由基中，根部仅在另一个垂直站立的芳基与分子框架的其余部分进行离域。超氧与双键反应，当它形成二乙烷样分子时，受体双键由于存在垂直固定的苯并二利自由基而无法帮助旋转预定的方向。机械细节和相关的双音阳离子自由基的其他反应也较少。

项目成果

Yasuhiko Kawamura: "One-and Two-Way Geometrical Isomerizations of 1, 1-Diarylketone Oxime O-Methyl Ethers Induced by Photosensitized Electron Transfer"Internat. J. Mod. Phys. B. Vol.17, Nos.1 & 2. 349-354 (2003)

Yasuhiko Kawamura：“光敏电子转移诱导的 1, 1-二芳基酮肟 O-甲基醚的单向和双向几何异构化”Internat。

Yasuhiko Kawamura: "One-Way Geometrical Isomerization of 1, 1-Diarylethenes Induced by Photosensitized Electron Transfer"Internat. J. Mod. Phys. B. Vol.17, Nos.1 & 2. 355-360 (2003)

Yasuhiko Kawamura：“光敏电子转移诱导的 1, 1-二芳基乙烯的单向几何异构化”Internat。

Yasuhiko Kawamura: "One-Way Geometrical Isomerization of 1,1-Diarylethenes Induced by Photosensitized Electron Transfer"Internat.J.Mod.Phys.B. Vol.17, Nos.1 & 2. 355-360 (2003)

Yasuhiko Kawamura：“光敏电子转移诱导的 1,1-二芳基乙烯的单向几何异构化”Internat.J.Mod.Phys.B。

Yasuhiko Kawamura: "Curious Oxygen Effect on Photosensitized Electron-Transfer Reactions of Benzophenone Oxime O-Methyl Ethers : One-Way Photoisomerization of an Iminic Double Bond"Tetrahedron Lett.. Vol.41, No.42. 8101-8106 (2000)

Yasuhiko Kawamura：“奇怪的氧对二苯甲酮肟 O-甲基醚光敏电子转移反应的影响：亚胺双键的单向光异构化”Tetrahedron Lett.. 第 41 卷，第 42 期。

Yasuhiko Kawamura: "One- and Two-Way Geometrical Isomerizations of 1,1-Diaryl-ketone Oxime O-Methyl Ethers Induced by Photosensitized Electron Transfer"Internat.J.Mod.Phys.B. Vol.17, Nos.1 & 2. 349-354 (2003)

Yasuhiko Kawamura：“光敏电子转移诱导的 1,1-二芳基酮肟 O-甲基醚的单向和双向几何异构化”Internat.J.Mod.Phys.B。