title: Two-Step Photon Absorption Driving the Chemical Reaction in the Model Ruthenium Nitrosyl System [Ru(py)4Cl(NO)](PF6)2·(1)/2H2O.
abstract: Various systems containing the [ML5NO] molecule, where M = Fe, Ru, ... and L = F, Cl, ..., exhibit switching under continuous light (CW) irradiation between the ground-state nitrosyl (GS), isonitrosyl (MSI), and side-on (MSII) configurations. The metastable populations, however, are often limited to a few percent. The [Ru(py)4Cl(NO)](PF6)2·(1)/2H2O system is thus a remarkable model compound as the GS to MSI transformation is nearly complete in a single crystal. A predominant two-step photon absorption process during GS to MSI switching under blue light is revealed by visible absorption spectroscopy, although a low concentration of the transient species hinders the determination of this process by the structural signature. During the depopulation of MSI, both two-step and direct processes are evidenced under red CW irradiation. Different intermediate visible spectra revealing transient species during GS to MSI and the reverse photochemical processes are discussed in relation to MSII properties.
authors.affiliation: Institut de Physique de Rennes, UMR UR1-CNRS 6251, Université Rennes 1 , avenue du général Leclerc, Rennes 35042 Cedex, France.
authors.forename: Liya
authors.initials: L
authors.lastname: Khadeeva
authors.affiliation: Institut de Physique de Rennes, UMR UR1-CNRS 6251, Université Rennes 1 , avenue du général Leclerc, Rennes 35042 Cedex, France.
authors.forename: Wawrzyniec
authors.initials: W
authors.lastname: Kaszub
authors.affiliation: Institut de Physique de Rennes, UMR UR1-CNRS 6251, Université Rennes 1 , avenue du général Leclerc, Rennes 35042 Cedex, France.
authors.forename: Maciej
authors.initials: M
authors.lastname: Lorenc
authors.affiliation: Laboratoire de Chimie de Coordination, CNRS UPR 8241 , 205 route de Narbonne, Toulouse 31077 Cedex, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Malfant
authors.affiliation: Institut de Physique de Rennes, UMR UR1-CNRS 6251, Université Rennes 1 , avenue du général Leclerc, Rennes 35042 Cedex, France.
authors.forename: Marylise
authors.initials: M
authors.lastname: Buron-Le Cointe