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Updated: Jul 12, 2026
10:40
High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Photoinduced Enhancement of Chemical Shift Sensitivity to Local Vibrations
Ana Martínez Gutiérrez1, Oliver Alexander2, Pablo Estévez Alonso1
1Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (ICMM-CSIC) , 28049Madrid, Spain.
Journal of the American Chemical Society
|July 10, 2026
Summary
Novel time-resolved X-ray photoelectron spectroscopy (tr-XPS) reveals how electronic excitation and nuclear motion influence chemical environments in real-time. The nitrogen site in fluoropyridine is sensitive to electronic changes and vibrations, unlike the fluorine site.
Area of Science:
- Chemical Physics
- Ultrafast Spectroscopy
- Molecular Dynamics
Background:
- Time-resolved X-ray photoelectron spectroscopy (tr-XPS) with free-electron lasers allows real-time monitoring of chemical environments.
- Core-electron binding energy shifts reveal the interplay between electronic excitation and nuclear motion.
- This interplay is crucial for understanding molecular dynamics but remains largely unexplored.
Purpose of the Study:
- Investigate the link between electronic excitation and nuclear motion in fluoropyridine.
- Monitor the evolving chemical environment at N and F atomic sites during excited-state relaxation.
- Understand how photoexcitation affects site-specific responses to vibrations.
Main Methods:
- Combined theoretical and experimental study of fluoropyridine (C5H4FN).
- Utilized time-resolved X-ray photoelectron spectroscopy (tr-XPS).
- Analyzed core-electron binding energy shifts at N and F sites during S1 state relaxation via a conical intersection.
Main Results:
- The fluorine site showed minimal sensitivity to the electronic excited state, responding mainly to vibrational relaxation.
- The nitrogen site exhibited a measurable energy shift upon S1 excitation, enhancing its sensitivity to local vibrations.
- Photoinduced charge redistribution at the N site increased Coulomb interaction with an adjacent carbon atom.
Conclusions:
- The nitrogen site's enhanced sensitivity is linked to photoinduced charge redistribution and Coulomb interactions.
- Different atomic sites respond distinctively to electronic excitation and vibrational relaxation.
- This study provides insights into ultrafast dynamics and conical intersection pathways in complex molecular systems.
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