Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 4038-4046 |
| Seitenumfang | 9 |
| Fachzeitschrift | Journal of Physical Chemistry Letters |
| Jahrgang | 16 |
| Ausgabenummer | 16 |
| Frühes Online-Datum | 15 Apr. 2025 |
| Publikationsstatus | Veröffentlicht - 24 Apr. 2025 |
Abstract
The photophysics of nucleobases has been the subject of both theoretical and experimental studies over the past decades due to the challenges posed by resolving the steps of their radiationless relaxation dynamics, which cannot be described in the framework of the Born-Oppenheimer approximation (BOA). In this context, the ultrafast dynamics of 2-thiouracil has been investigated with a time-resolved NEXAFS study at the Free Electron Laser FLASH. Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS) can be used to observe electronic transitions in ultrafast molecular relaxation. We performed time-resolved UV-pump/X-ray probe absorption measurements at the sulfur 2s (L1) and 2p (L2/3) edges. We are able to identify absorption features corresponding to the S2 (ππ*) and S1 (nπ*) electronic states. We observe a delay of 102 ± 11 fs in the population of the nπ* state with respect to the initial optical excitation and interpret the delay as the time scale for the S2 → S1 internal conversion. We furthermore identify oscillations in the absorption signal that match a similar observation in our previous X-ray photoelectron spectroscopy study on the same molecule.
ASJC Scopus Sachgebiete
- Werkstoffwissenschaften (insg.)
- Allgemeine Materialwissenschaften
- Chemie (insg.)
- Physikalische und Theoretische Chemie
Zitieren
- Standard
- Harvard
- Apa
- Vancouver
- BibTex
- RIS
in: Journal of Physical Chemistry Letters, Jahrgang 16, Nr. 16, 24.04.2025, S. 4038-4046.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Direct Observation of the ππ* to nπ* Transition in 2-Thiouracil via Time-Resolved NEXAFS Spectroscopy
AU - Lever, Fabiano
AU - Picconi, David
AU - Mayer, Dennis
AU - Ališauskas, Skirmantas
AU - Calegari, Francesca
AU - Düsterer, Stefan
AU - Feifel, Raimund
AU - Kuhlmann, Marion
AU - Mazza, Tommaso
AU - Metje, Jan
AU - Robinson, Matthew S.
AU - Squibb, Richard J.
AU - Trabattoni, Andrea
AU - Ware, Matthew
AU - Saalfrank, Peter
AU - Wolf, Thomas J.A.
AU - Gühr, Markus
N1 - Publisher Copyright: © 2025 The Authors. Published by American Chemical Society.
PY - 2025/4/24
Y1 - 2025/4/24
N2 - The photophysics of nucleobases has been the subject of both theoretical and experimental studies over the past decades due to the challenges posed by resolving the steps of their radiationless relaxation dynamics, which cannot be described in the framework of the Born-Oppenheimer approximation (BOA). In this context, the ultrafast dynamics of 2-thiouracil has been investigated with a time-resolved NEXAFS study at the Free Electron Laser FLASH. Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS) can be used to observe electronic transitions in ultrafast molecular relaxation. We performed time-resolved UV-pump/X-ray probe absorption measurements at the sulfur 2s (L1) and 2p (L2/3) edges. We are able to identify absorption features corresponding to the S2 (ππ*) and S1 (nπ*) electronic states. We observe a delay of 102 ± 11 fs in the population of the nπ* state with respect to the initial optical excitation and interpret the delay as the time scale for the S2 → S1 internal conversion. We furthermore identify oscillations in the absorption signal that match a similar observation in our previous X-ray photoelectron spectroscopy study on the same molecule.
AB - The photophysics of nucleobases has been the subject of both theoretical and experimental studies over the past decades due to the challenges posed by resolving the steps of their radiationless relaxation dynamics, which cannot be described in the framework of the Born-Oppenheimer approximation (BOA). In this context, the ultrafast dynamics of 2-thiouracil has been investigated with a time-resolved NEXAFS study at the Free Electron Laser FLASH. Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS) can be used to observe electronic transitions in ultrafast molecular relaxation. We performed time-resolved UV-pump/X-ray probe absorption measurements at the sulfur 2s (L1) and 2p (L2/3) edges. We are able to identify absorption features corresponding to the S2 (ππ*) and S1 (nπ*) electronic states. We observe a delay of 102 ± 11 fs in the population of the nπ* state with respect to the initial optical excitation and interpret the delay as the time scale for the S2 → S1 internal conversion. We furthermore identify oscillations in the absorption signal that match a similar observation in our previous X-ray photoelectron spectroscopy study on the same molecule.
UR - http://www.scopus.com/inward/record.url?scp=105002769831&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.5c00544
DO - 10.1021/acs.jpclett.5c00544
M3 - Article
C2 - 40232202
AN - SCOPUS:105002769831
VL - 16
SP - 4038
EP - 4046
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 16
ER -