title: Fast and slow excited-state intramolecular proton transfer in 3-hydroxychromone: a two-state story?
abstract: The photodynamics of 3-hydroxychromone in its first-excited singlet electronic state (bright state of ππ* character) is investigated with special emphasis given to two types of reaction pathways: the excited-state intramolecular-proton-transfer coordinate and the hydrogen-torsion coordinate linking the excited cis and trans isomers. A newly-found conical intersection with the second-excited singlet electronic state (dark state of nπ* character) is suspected to be, to some extent, the reason for the slower rate constant. This hypothesis based on quantum-chemistry calculations is supported by quantum-dynamics simulations in full dimensionality. They show significant transfer of electronic population and provide consistently a vibronic interpretation for the forbidden band in the UV absorption spectrum.
authors.affiliation: Laboratoire de Chimie Physique (UMR 8000), CNRS, Université Paris-Sud, F-91405 Orsay, France. perveaux@tugraz.at and Institut Charles Gerhardt (UMR 5253), CNRS, Université de Montpellier, F-34095 Montpellier, France.
authors.forename: Aurelie
authors.initials: A
authors.lastname: Perveaux
authors.affiliation: Laboratoire de Chimie Physique (UMR 8000), CNRS, Université Paris-Sud, F-91405 Orsay, France. perveaux@tugraz.at.
authors.forename: Maxime
authors.initials: M
authors.lastname: Lorphelin
authors.affiliation: Institut Charles Gerhardt (UMR 5253), CNRS, Université de Montpellier, F-34095 Montpellier, France.
authors.forename: Benjamin
authors.identifier: http://orcid.org/0000-0002-9943-1905
authors.initials: B
authors.lastname: Lasorne
authors.affiliation: Laboratoire de Chimie Physique (UMR 8000), CNRS, Université Paris-Sud, F-91405 Orsay, France. perveaux@tugraz.at.
authors.forename: David
authors.identifier: http://orcid.org/0000-0002-8258-3531
authors.initials: D
authors.lastname: Lauvergnat