Ultrafast photochemistry and electron-diffraction spectra in n → (3s) Rydberg excited cyclobutanone resolved at the multireference perturbative level

V K Jaiswal; F Montorsi; F Aleotti; F Segatta; Daniel Keefer; Shaul Mukamel; A Nenov; I Conti; M Garavelli

doi:10.1063/5.0203624

Ultrafast photochemistry and electron-diffraction spectra in n → (3s) Rydberg excited cyclobutanone resolved at the multireference perturbative level

J Chem Phys. 2024 Apr 28;160(16):164316. doi: 10.1063/5.0203624.

Authors

V K Jaiswal¹, F Montorsi¹, F Aleotti¹, F Segatta¹, Daniel Keefer², Shaul Mukamel³, A Nenov¹, I Conti¹, M Garavelli¹

Affiliations

¹ Dipartimento di Chimica industriale "Toso Montanari," Università di Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy.
² Molecular Spectroscopy Department, Max Planck Institute for Polymer Research, Mainz 55128, Germany.
³ Department of Chemistry and Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA.

PMID: 38686819
DOI: 10.1063/5.0203624

Abstract

We study the ultrafast time evolution of cyclobutanone excited to the singlet n → Rydberg state through non-adiabatic surface-hopping simulationsperformed at extended multi-state complete active space second-order perturbation (XMS-CASPT2) level of theory. These dynamics predict relaxation to the ground-state with a timescale of 822 ± 45 fs with minimal involvement of the triplets. The major relaxation path to the ground-state involves a three-state degeneracy region and leads to a variety of fragmented photoproducts. We simulate the resulting time-resolved electron-diffraction spectra, which track the relaxation of the excited state and the formation of various photoproducts in the ground state.