X-ray Transient Absorption Reveals The ¹a_u (nπ*) State Of Pyrazine In Electronic Relaxation

Scutelnic, Valeriu

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https://hdl.handle.net/2142/111337 Copy

Description

Title

X-ray Transient Absorption Reveals The ¹a_u (nπ*) State Of Pyrazine In Electronic Relaxation

Author(s)

Scutelnic, Valeriu

Contributor(s)

• Leone, Stephen R.
• Coriani, Sonia
• Møller, Klaus
• Krylov, Anna
• Kobayashi, Yuki
• Haugen, Eric
• Xue, Tian
• Epshtein, Michael
• Yang, Zheyue
• Pápai, Mátyás
• Tsuru, Shota

Issue Date

2021-06-24

Keyword(s)

Dynamics and kinetics

Abstract

X-rays promote electrons from the core levels to vacant valence orbitals, thus endowing them with a unique element specificity. Moreover, the core level transitions can easily sense the shifts in the electron density in the proximity of the probed element. We produce soft X-rays around 280 eV driving high harmonics in a helium gas target with 1470 nm pulses. This table-top broad band X-ray source allows us to investigate the ultrafast dynamics in photoexcited pyrazine (C$_{4}$H$_{4}$N$_{2}$) with a new view of the electronic states involved. In addition to the previously characterized $^{1}$B$_{2u}$ ($\pi$$\pi$*) (S$_{2}$) and $^{1}$B$_{3u}$ (n$\pi$*) (S$_{1}$) states, the participation of the optically dark $^{1}$A$_{u}$ (n$\pi$*) state is assigned by a combination of experimental X-ray core-to-valence spectroscopy, electronic structure calculations and nonadiabatic dynamics simulations. The $^{1}$A$_{u}$ (n$\pi$*) state is populated about 200 femtoseconds after electronic excitation and plays a key role in the relaxation of pyrazine to the ground state.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111337

DOI

10.15278/isms.2021.RJ12

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