Coherent structural trapping through wave packet dispersion during photoinduced spin state switching

Henrik T. Lemke, Kasper Skov Kjær, Robert Hartsock, Tim Brandt van Driel, Matthieu Chollet, James M. Glownia, Sanghoon Song, Diling Zhu, Elisabetta Pace, Samir F. Matar, Martin Meedom Nielsen, Maurizio Benfatto, Kelly J. Gaffney, Eric Collet, Marco Cammarata

Research output: Contribution to journalJournal articleResearchpeer-review

361 Downloads (Pure)


The description of ultrafast nonadiabatic chemical dynamics during molecular photo-transformations remains challenging because electronic and nuclear configurations impact each other and cannot be treated independently. Here we gain experimental insights, beyond the Born-Oppenheimer approximation, into the light-induced spin-state trapping dynamics of the prototypical [Fe(bpy)3]2+ compound by time-resolved X-ray absorption spectroscopy at sub-30-femtosecond resolution and high signal-to-noise ratio. The electronic decay from the initial optically excited electronic state towards the high spin state is distinguished from the structural trapping dynamics, which launches a coherent oscillating wave packet (265 fs period), clearly identified as molecular breathing. Throughout the structural trapping, the dispersion of the wave packet along the reaction coordinate reveals details of intramolecular vibronic coupling before a slower vibrational energy dissipation to the solution environment. These findings illustrate how modern time-resolved X-ray absorption spectroscopy can provide key information to unravel dynamic details of photo-functional molecules.
Original languageEnglish
Article number15342
JournalNature Communications
Number of pages8
Publication statusPublished - 2017

Bibliographical note

This work is licensed under a Creative Commons Attribution 4.0 International License.


  • Chemical physics
  • Other photonics
  • Photochemistry


Dive into the research topics of 'Coherent structural trapping through wave packet dispersion during photoinduced spin state switching'. Together they form a unique fingerprint.

Cite this