Intersystem Crossing and Nonadiabatic Product Channels in the Photodissociation of N2O4 at 193 nm
Intersystem Crossing and Nonadiabatic Product Channels in the Photodissociation of N2O4 at 193 nm
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193 nm N2O4 光解离中的系间交叉和非绝热产物通道
DOI：
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发表时间：
2000
期刊：
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通讯作者：
L. Butler
中科院分区：
文献类型：
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作者：
J. A. Mueller;Melita L. Morton;S. Curry;J. Abbatt;L. Butler
本文介绍了在193nm光解N2O4产物的速度和角分布的测量。数据显示只有N - N键裂变，没有明显分支到N - O键裂变或no消除产物。N - N键裂变产物的平动能分布呈双峰分布，表明至少有两种不同的NO2 + NO2产物通道对所观察到的产物有显著贡献。两种产品通道的各向异性参数均为β = 1.7±0.2。利用Franck - condon样突变分析，我们初步将观察到的两个断裂通道划分为NO2(X2A1) + NO2（14B2/14A2）和NO2(X2A1) + NO2（22B2）。为了进一步表征该系统，我们提出了N2O4相关激发态的从头计算（在单激发的组态相互作用水平上）。考虑的数据和计算提出了一个在Franck - Condon区域存在自旋-轨道耦合的产物分支模型。
This paper presents velocity and angular distribution measurements of the products of N2O4 photodissociated at 193 nm. The data show evidence for only N−N bond fission, with no significant branching to N−O bond fission or NO elimination products. The translational energy distribution of the N−N bond fission products is bimodal, indicating that at least two different NO2 + NO2 product channels contribute significantly to the observed products. Both product channels have an anisotropy parameter of β = 1.7 ± 0.2. Using a Franck−Condon-like sudden analysis, we tentatively assign the two fragmentation channels observed as NO2(X2A1) + NO2(14B2/14A2) and NO2(X2A1) + NO2(22B2). To further characterize the system we present ab initio calculations (at the level of configuration interaction with single excitations) of the relevant excited states of N2O4. The data considered together with the calculations suggest a model for the product branching in which there is spin−orbit coupling in the Franck−Condon region bet...