Indian Institute of Science Education and Research-Kolkata, Mohanpur, Nadia 741252, India.
Phys Chem Chem Phys. 2011 Jan 28;13(4):1542-51. doi: 10.1039/c0cp01067g. Epub 2010 Dec 6.
An experimental and theoretical investigation of the dissociative electron attachment process in nitric oxide is presented. Measurements using the recently developed ion momentum imaging conclusively show the presence of two resonance features in the O(-) channel. These are found to dissociate to give N atoms in the (2)D and (2)P excited states respectively, thus settling the controversies regarding the possible dissociation limits of this process. Though the angular distribution of O(-) shows the resonances contributing to these dissociations are of Π symmetry and a mixture of Π and Σ or Δ symmetry respectively, our calculations using R-matrix theory show no direct electron attachment channel leading to O(-) through these resonances, as all the allowed resonances below 10 eV decay to either O + N(-) or O(-) + N((4)S) channels. We propose that indirect mechanisms through curve crossings lead to the experimentally observed results.
本文对一氧化氮中的电子离解过程进行了实验和理论研究。使用最近开发的离子动量成像技术进行的测量明确表明，在 O(-) 通道中存在两个共振特征。这些共振特征分别分解为 (2)D 和 (2)P 激发态的 N 原子，从而解决了关于该过程可能的离解极限的争议。尽管 O(-) 的角分布表明，对这些离解有贡献的共振是 Π 对称性，分别是 Π 和 Σ 或 Δ 对称性的混合物，但我们使用 R 矩阵理论进行的计算表明，没有直接的电子附加通道通过这些共振导致 O(-)，因为所有低于 10 eV 的允许共振都衰减到 O + N(-) 或 O(-) + N((4)S) 通道。我们提出，通过曲线交叉的间接机制导致了实验观察到的结果。
