Study on non-dissociative bimolecular reactions characteristic of contact molecular pairs

接触分子对非解离双分子反应特性研究

• 批准号: 17350005
• 负责人: SHIBUYA Kazuhiko
• 金额: $ 9.73万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17350005/
• 关键词: ozone; water complex; photochemistry; hydroxyl radical; atmospheric chemistry; O(^1D); IR spectroscopy; reaction mechanism; 化学物理; 環境変動; 自然現象観測・予測; 地球化学; 地球科学

Ozone-water complex has been suggested as one of the hydroxyl radical sources in the Earth's troposphere. Complexation with water vapor might change the O_3 photochemistry, which might play a crucial role in the production of hydroxyl radical. We have characterized the spectroscopy of O_3-H_2O complex. In this research, the photochemistry of ozone-water complex isolated in cryogenic matrices was studied. Neon, argon, and krypton were employed as matrix media to study the so-called matrix cage effect and to develop the solid state chemistry to the gas phase reaction. Wavelength dependence of photochemistry was studied by using UV and visible light.Ozone ν_3 fundamental region was chosen to monitor the occurrence of ozone photo-dissociation within the monomer and ozone-water complex, because the ν_3 fundamental of the ozone-water complex was fully separated from the monomer ν_3 band. In a neon matrix, the irradiation by 355 nm led to the decreases of ozone monomer and ozone water complex and to the formation of hydrogen peroxide. Apparently the photo-dissociation of ozone was found to take place even at 355 nm. In argon and krypton matrices, the formation of hydrogen peroxide-water complex was also observed, which is thought to be formed from an inter-cage reaction of cage-exited O(^1D) atom with water dimer in a different cage. A hydrogen peroxide formation yield in a neon matrix is estimated to be almost unity, whereas those in argon and krypton exceed unity because of the inter-cage reaction. We concluded that neon is most appropriate media for studying the photochemistry of ozone-water complex. Wavelength dependence was studied in the solid neon. The 254- and 313-nm irradiations gave the similar results at the 355 nm irradiation, but the 365- and 633-nm irradiation did not induce any photochemical reaction. We will discuss the photochemical mechanism (dependence of wavelength and matrix cage) and the implication of the atmospheric ozone chemistry.

臭氧-水复合物被认为是地球对流层中羟基自由基的来源之一。与水蒸气的络合作用可能改变O_3的光化学性质，这可能在羟基自由基的产生中起重要作用。我们对O_3-H_2O络合物的光谱进行了表征。在这项研究中，臭氧-水复合物在低温基质中的光化学分离进行了研究。采用氖、氩和氪作为基质介质来研究所谓的基质笼效应，并将固态化学发展到气相反应。用紫外光和可见光研究了光化学的波长依赖性，由于臭氧-水复合物的ν_3基频与单体ν_3带完全分离，因此选择臭氧ν_3基频区来监测单体和臭氧-水复合物中臭氧的光解。在氖基质中，355 nm的辐照导致臭氧单体和臭氧水复合物的减少以及过氧化氢的形成。显然，甚至在355 nm处也发现臭氧的光解。在氩和氪中，也观察到过氧化氢-水复合物的形成，这被认为是由笼激发的O（^1D）原子与不同笼中的水二聚体的笼间反应形成的。氖基质中的过氧化氢生成产率估计几乎为1，而氩和氪中的过氧化氢生成产率由于笼间反应而超过1。因此，氖是研究臭氧-水复合物光化学的最适宜介质。在固体氖中研究了波长依赖性。254-和313-nm的照射在355 nm的照射下得到类似的结果，但365-和633-nm的照射没有诱导任何光化学反应。我们将讨论光化学机制（波长和矩阵笼的依赖性）和大气臭氧化学的含义。

项目成果

Evidence for a non-planar conformer and conformational isomerization of o-fluoroanisole in a low-temperature Ar matrix

• DOI: 10.1016/j.cplett.2005.04.086
• 发表时间: 2005-06-20
• 期刊: CHEMICAL PHYSICS LETTERS
• 影响因子: 2.8
• 作者: Isozaki, T;Sakeda, K;Shibuya, K
• 通讯作者: Shibuya, K

Enhanced intersystem crossing of S1-T1 and T1-S0 in coronene-galvinoxyl systems as studied by a pulsed ESR method

通过脉冲 ESR 方法研究晕苯-加尔万氧基体系中 S1-T1 和 T1-S0 的增强系间窜越

• 发表时间: 2006
• 期刊: Photobio. A: Chem. 183
• 作者: Hajime Terazono;Akio Kawai;Kazuhide Tsuji;Kazuhiko Shibuya J. Photochem.
• 通讯作者: Kazuhiko Shibuya J. Photochem.

Electron spin dynamics in radical and electronically-excited molecular pair interaction as studied a time-resolved ESR method

通过时间分辨 ESR 方法研究自由基和电子激发分子对相互作用中的电子自旋动力学

• 发表时间: 2006
• 期刊: J. Photochem. Photobio. C : Photochemistry Reviews 7
• 作者: A.Kawai;K.Shibuya
• 通讯作者: K.Shibuya

Jet Spectroscopy of Arylmethyl Radicals in the Visible Region : Assignment of Low-Frequency Vibrational Modes in Diphenylmethyl and Chlorodiphenylmethl Radicals

可见光区域芳甲基自由基的喷射光谱：二苯甲基和氯二苯甲基自由基的低频振动模式的分配

• 发表时间: 2006
• 期刊: Phys. Chem. Chem. Phys. 8
• 作者: M.Tsuge;S.Hamatani;A.Kawai;K.Tsuji;K.Shibuya
• 通讯作者: K.Shibuya

Electron spin dynamics in radical, electronically-excited molecular pair interaction as studied a time-resolved ESR method

通过时间分辨 ESR 方法研究自由基、电子激发分子对相互作用中的电子自旋动力学

• 发表时间: 2006
• 期刊: J.Photochem.Photobio.C : Photochemistry Reviews 7
• 作者: A.Kawai;K.Shibuya
• 通讯作者: K.Shibuya