Photodissociation dynamics of free radicals

自由基的光解离动力学

• 批准号: 07640694
• 负责人: TONOKURA Kenichi
• 金额: $ 1.47万
• 依托单位: Okazaki National Research Institutes
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640694/
• 关键词: vinyl radical; ion imaging; vinylchloride; dichloroethylene; 光解離; ラジカル; クロロエチレン

Photochemical reaction of free radicals plays an important role in the atmospheric and interstellar chemical reactions. The dissociation dynamics of C_nH_m have been studied by using two dimensional ion imaging method.In the photoexcitation into (pi, pi<@D1**@>D1) state of vinylchloride dissociates into vinyl radical and chlorine atom. The translational energy distribution consists of two components ; one is a Gaussian-like translational energy distribution with high anisotropy, beta=1.0(]SY.+-。[)0.2, while the other is a statistical distribution with low anisotropy, beta=0.3 (]SY.+-。[) 0.2. The dissociation rate constants for the low translational energy component is estimated to be 10<@D111@>D1- 10<@D112@>D1 s<@D1-1@>D1.In the case of ultraviolet photodissociation of dichloroethylenes, there exists secondary dissociation of C_2H_2Cl radical following to chlorine atom and acetylene. At 193 nm photoexcitation, about 100% of C_2H_2Cl radical undergo to the secondary dissociation.

自由基光化学反应在大气和星际化学反应中起着重要作用。用二维离子成像法研究了CnHm的解离动力学。在光激发(pi，pi&lt；@d1*@&gt；d1)状态下，氯乙烯解离为乙烯基和氯原子。平移能量分布由两个分量组成：一个是具有高各向异性的高斯型平移能量分布，β=1.0(]sy+-)。[)0.2，而另一种是低各向异性的统计分布，β=0.3(]sy+-。[)0.2.计算得到低平动能组分的解离速率常数为10&lt；@D111@&gt；d1-10&lt；@d112@&gt；d1 S&lt；@d1-1@&gt；d1。在二氯乙烯紫外光解离的情况下，氯原子和乙炔之后存在C_2H_2Cl自由基的二次解离。在193 nm光激发下，约100%的C_2H_2Cl自由基发生二次解离。