Resonances in nitrobenzene probed by the electron attachment to neutral and by the photodetachment from anion

0560527 - ÚFCH JH 2023 RIV US eng J - Journal Article
Ranković, Miloš - Nag, Pamir - Anstoter, C. S. - Mensa-Bonsu, G. - Kumar, Ragesh Thelakkadan Puthiyaveettil - Verlet, J.R.R. - Fedor, Juraj
Resonances in nitrobenzene probed by the electron attachment to neutral and by the photodetachment from anion.
Journal of Chemical Physics. Roč. 157, č. 6 (2022), č. článku 064302. ISSN 0021-9606. E-ISSN 1089-7690
R&D Projects: GA ČR(CZ) GA20-11460S
Institutional support: RVO:61388955
Keywords : transient anions * electron attachment * resonance
OECD category: Physical chemistry
Impact factor: 4.4, year: 2022
Method of publishing: Open access

We probe resonances (transient anions) in nitrobenzene with the focus on the electron emission from these. Experimentally, we populate resonances in two ways: either by the impact of free electrons on the neutral molecule or by the photoexcitation of the bound molecular anion. These two excitation means lead to transient anions in different initial geometries. In both cases, the anions decay by electron emission and we record the electron spectra. Several types of emission are recognized, differing by the way in which the resulting molecule is vibrationally excited. In the excitation of specific vibrational modes, distinctly different modes are visible in electron collision and photodetachment experiments. The unspecific vibrational excitation, which leads to the emission of thermal electrons following the internal vibrational redistribution, shows similar features in both experiments. A model for the thermal emission based on a detailed balance principle agrees with the experimental findings very well. Finally, a similar behavior in the two experiments is also observed for a third type of electron emission, the vibrational autodetachment, which yields electrons with constant final energies over a broad range of excitation energies. The entrance channels for the vibrational autodetachment are examined in detail, and they point to a new mechanism involving a reverse valence to non-valence internal conversion. Published under an exclusive license by AIP Publishing.
Permanent Link: https://hdl.handle.net/11104/0333440