title: Sequential Activation of Molecular Breathing and Bending during Spin-Crossover Photoswitching Revealed by Femtosecond Optical and X-Ray Absorption Spectroscopy.
abstract: We study the basic mechanisms allowing light to photoswitch at the molecular scale a spin-crossover material from a low- to a high-spin state. Combined femtosecond x-ray absorption performed at LCLS X-FEL and optical spectroscopy reveal that the structural stabilization of the photoinduced high-spin state results from a two step structural trapping. Molecular breathing vibrations are first activated and rapidly damped as part of the energy is sequentially transferred to molecular bending vibrations. During the photoswitching, the system follows a curved trajectory on the potential energy surface.
authors.affiliation: Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Marco
authors.initials: M
authors.lastname: Cammarata
authors.affiliation: Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Roman
authors.initials: R
authors.lastname: Bertoni
authors.affiliation: Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Maciej
authors.initials: M
authors.lastname: Lorenc
authors.affiliation: Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Cailleau
authors.affiliation: Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Sergio
authors.initials: S
authors.lastname: Di Matteo
authors.affiliation: CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr. A. Schweitzer, Pessac 33608, France.
authors.forename: Cindy
authors.initials: C
authors.lastname: Mauriac
authors.affiliation: CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr. A. Schweitzer, Pessac 33608, France.
authors.forename: Samir F
authors.initials: SF
authors.lastname: Matar
authors.affiliation: LCLS, SLAC National Laboratory, Menlo Park, California 94025, USA.
authors.forename: Henrik
authors.initials: H
authors.lastname: Lemke
authors.affiliation: LCLS, SLAC National Laboratory, Menlo Park, California 94025, USA.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Chollet
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Ravy
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Laulhé
authors.affiliation: CNRS, Université de Bordeaux, ICMCB, 87 Avenue du Dr. A. Schweitzer, Pessac 33608, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Létard
authors.affiliation: Institut de Physique de Rennes, UMR CNRS 6251, Université Rennes 1, 35042 Rennes Cedex, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Collet