Ultrafast electronic relaxation pathways of the molecular photoswitch quadricyclane

Authors

• Kurtis D. Borne, Kansas State University
• Joseph C. Cooper, University of Oxford
• Michael N. R. Ashfold, University of Bristol
• Julien Bachmann, Friedrich-Alexander-Universität Erlangen-Nürnberg
• Surjendu Bhattacharyya, Kansas State University
• Rebecca Boll5, European XFEL
• Matteo Bonanomi, Istituto di Fotonica e Nanotecnologie, Dipartimento di Fisica
• Michael Bosch, Friedrich-Alexander-Universität Erlangen-Nürnberg
• Carlo Callegari, Elettra – Sincrotrone Trieste S.C.p.A.
• Martin Centurion, University of Nebraska - LincolnFollow
• Marcello Coreno, Elettra – Sincrotrone Trieste S.C.p.A., Istituto di Struttura della Materia
• Basile F. E. Curchod, University of Bristol
• Miltcho B. Danailov, Elettra – Sincrotrone Trieste S.C.p.A.
• Alexander Demidovich, Elettra – Sincrotrone Trieste S.C.p.A.
• Michele Di Fraia, Elettra – Sincrotrone Trieste S.C.p.A.
• Benjamin Erk, Deutsches Elektronen-Synchrotron DESY
• Davide Faccialà, Istituto di Fotonica e Nanotecnologie
• Raimund Feifel, University of Gothenburg
• Ruaridh J. G. Forbes, SLAC National Accelerator Laboratory
• Christopher S. Hansen, University of New South Wales
• David M. P. Holland, Daresbury Laboratory
• Rebecca A. Ingle, University College London
• Roland Lindh, Uppsala University
• Lingyu Ma, Brown University
• Henry G. McGhee, University College London
• Sri Bhavya Muvva, University of Nebraska-LincolnFollow
• Joao Pedro Figueira Nunes, University of Nebraska-Lincoln
• Asami Odate, Brown University
• Shashank Pathak, Kansas State University
• Oksana Plekan, Elettra – Sincrotrone Trieste S.C.p.A.
• Kevin C. Prince, Elettra – Sincrotrone Trieste S.C.p.A.
• Primoz Rebernik, Elettra – Sincrotrone Trieste S.C.p.A.
• Arnaud Rouzée, Max-Born-Institut
• Artem Rudenko, Kansas State University
• Alberto Simoncig, Elettra – Sincrotrone Trieste S.C.p.A.
• Richard J. Squibb, University of Gothenburg
• Anbu Selvam Venkatachalam, Kansas State University
• Caterina Vozzi, Instituto di Fotonica e Nanotecnologie
• Peter M. Weber, Brown University
• Adam Kirrander, University of Oxford
• Daniel Rolles, Kansas State University

Document Type

Article

Date of this Version

12-11-2023

Citation

Nature Chemistry | Volume 16 | April 2024 | 499–505. https://doi.org/10.1038/s41557-023-01420-w

Comments

Open access.

Abstract

The light-induced ultrafast switching between molecular isomers norbornadiene and quadricyclane can reversibly store and release a substantial amount of chemical energy. Prior work observed signatures of ultrafast molecular dynamics in both isomers upon ultraviolet excitation but could not follow the electronic relaxation all the way back to the ground state experimentally. Here we study the electronic relaxation of quadricyclane after exciting in the ultraviolet (201 nanometres) using time-resolved gas-phase extreme ultraviolet photoelectron spectroscopy combined with non-adiabatic molecular dynamics simulations. We identify two competing pathways by which electronically excited quadricyclane molecules relax to the electronic ground state. The fast pathway (<100 femtoseconds) is distinguished by effective coupling to valence electronic states, while the slow pathway involves initial motions across Rydberg states and takes several hundred femtoseconds. Both pathways facilitate interconversion between the two isomers, albeit on different timescales, and we predict that the branching ratio of norbornadiene/ quadricyclane products immediately after returning to the electronic ground state is approximately 3:2.