Tracking polar solvation dynamics of a photoexcited organic chromophore with ultrafast X-ray scattering
Solvation plays a key role in many photochemical and biological processes. Yet, direct atomic-scale observation of solvent reorganization around photoexcited molecules containing only light atoms has so far remained elusive. Here, we use time-resolved X-ray scattering at an X-ray free-electron laser to track with a ~ 120 fs time resolution the photoinduced ultrafast rearrangement of polar acetonitrile solvent molecules around an organic hemithioindigo chromophore. The experiments reveal that the solvation shell reorganizes with a ~ 0.3 ps time constant driven by photoinduced charge transfer in the chromophore, and then reequilibrates over ~ 3 ps as the excited state population returns to the ground state. These results demonstrate the viability of using ultrashort X-ray pulses to directly visualize the motion of light atoms in solution, paving the way for atomic-scale understanding and control of photoinduced processes in biological and synthetic photoactive organic molecules.
Authors
- Kristoffer Haldrup (ORCID: https://orcid.org/0000-0002-0565-6397)
- Claudio Cirelli (ORCID: https://orcid.org/0000-0003-4576-3805)
- Bianca L. Hansen (ORCID: https://orcid.org/0000-0002-4279-780X)
- Asmus Ougaard Dohn (ORCID: https://orcid.org/0000-0002-5172-7168)
- Verena Markmann
- M. Nielsen (ORCID: https://orcid.org/0000-0002-8135-434X)
- Philip J. M. Johnson (ORCID: https://orcid.org/0000-0002-7251-4815)
- Emma V. Beale (ORCID: https://orcid.org/0000-0002-7814-734X)
- Elli Selenius (ORCID: https://orcid.org/0000-0003-4286-0861)
- Luca Laraia (ORCID: https://orcid.org/0000-0001-6692-3412)
- Mikkel Krell-Jørgensen (ORCID: https://orcid.org/0000-0003-0079-1810)
- Camila Bacellar (ORCID: https://orcid.org/0000-0003-2166-241X)
- David J. Gosztola (ORCID: https://orcid.org/0000-0003-2674-1379)
- Gianluca Levi (ORCID: https://orcid.org/0000-0002-4542-0653)
- K. Möller
- Morten Haubro (ORCID: https://orcid.org/0000-0003-3869-6405)
- Victor Lorentzen
- Kerstin Mitterer (ORCID: https://orcid.org/0009-0003-6939-6277)
- Magnus A. H. Christiansen
- Joseph G. F. Hoock
Institutions
- Argonne National Laboratory (US)
- University of Trieste (IT)
- University of Iceland (IS)
- Paul Scherrer Institute (CH)
- Technical University of Denmark (DK)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-04-13
- DOI
- https://doi.org/10.1038/s41467-026-71635-1
- Primary Topic
- Laser-Matter Interactions and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00