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arXiv · 2604.02534

Angle-resolved photoelectron spectroscopy of the DABCO molecule probed with VUV radiation

Audrey Scognamiglio·Lou Barreau·Constant Schouder·Denis Cubaynes·Bérenger Gans·Éric Gloaguen·Gustavo A. Garcias·Laurent Nahon·Lionel Poisson
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Abstract

We report a study of the diazabicyclo[2.2.2]octane (DABCO) molecule photoionized using VUV synchrotron radiation in combination with an ion--electron coincidence spectrometer. We determine accurately the adiabatic ionization energy to $7.199\pm0.006$~eV. Two vibrational progressions of DABCO cation ground state are resolved at $847~\text{cm}^{-1}\pm27~\text{cm}^{-1}$ and $1257~\text{cm}^{-1}\pm67~\text{cm}^{-1}$, which we assign to modes of $e'$ symmetry. Analysis of the photoelectron angular distribution shows that the anisotropy parameter depends on the vibrational excitation. This dependence of the $\beta$ parameter with the vibrational excitation is attributed to the scattering of the outgoing wavefunction mediated by high-lying Rydberg states.

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Audrey Scognamiglio, Lou Barreau, Constant Schouder, Denis Cubaynes, Bérenger Gans, Éric Gloaguen, Gustavo A. Garcias, Laurent Nahon, Lionel Poisson. 2026-04-02. Angle-resolved photoelectron spectroscopy of the DABCO molecule probed with VUV radiation. https://arxiv.org/abs/2604.02534

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