title: Room Temperature Magnetic Switchability Assisted by Hysteretic Valence Tautomerism in a Layered Two-Dimensional Manganese-Radical Coordination Framework.
abstract: The manganese-nitronyl-nitroxide two-dimensional coordination polymer {[Mn2(NITIm)3]ClO4}n(1) (NITImH = 2-(2-imidazolyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-3-oxide-1-oxyl) undergoes an unusual hysteretic thermo-induced valence tautomeric transition near room temperature, during which the manganese(II) ions are oxidized to manganese(III) and two of the three deprotonated radicals (NITIm-) are reduced to their diamagnetic aminoxyl form (denoted NITRed2-). Upon cooling, the high-temperature species {[MnII2(NITIm)3]ClO4}n(1HT) turns into the low-temperature species {[MnIII2(NITRed)2(NITIm)]ClO4}n(1LT) around 274 K, while on heating the process is reversed at about 287 K. This valence tautomeric phenomenon is supported by temperature-dependent magnetic susceptibility measurements, differential scanning calorimetry (DSC), crystal structure determination, UV-vis absorption, X-ray absorption (XAS), and emission (XES) and electron paramagnetic resonance (EPR) spectroscopies in the solid state.
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, F-69622, Villeurbanne, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Lannes
authors.affiliation: Département de Chimie Physique, Université de Genève , 30 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
authors.forename: Yan
authors.initials: Y
authors.lastname: Suffren
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, F-69622, Villeurbanne, France.
authors.forename: Jean Bernard
authors.initials: JB
authors.lastname: Tommasino
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, F-69622, Villeurbanne, France.
authors.forename: Rodica
authors.initials: R
authors.lastname: Chiriac
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, F-69622, Villeurbanne, France.
authors.forename: François
authors.initials: F
authors.lastname: Toche
authors.affiliation: Univ Lyon, ENS de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342, Lyon, France.
authors.forename: Lhoussain
authors.initials: L
authors.lastname: Khrouz
authors.affiliation: Département de Chimie Moléculaire (UMR 5250), Université Joseph Fourier , Grenoble, France.
authors.forename: Florian
authors.initials: F
authors.lastname: Molton
authors.affiliation: Département de Chimie Moléculaire (UMR 5250), Université Joseph Fourier , Grenoble, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Duboc
authors.affiliation: BM30B/FAME Beamline, European Synchrotron for Research Facility (ESRF) , Grenoble, France.|Observatoire des Sciences de l'Univers de Grenoble (OSUG), CNRS UMS 832, 414 rue de la piscine, 38400 Saint Martin d'Hères, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Kieffer
authors.affiliation: BM30B/FAME Beamline, European Synchrotron for Research Facility (ESRF) , Grenoble, France.|Institut Néel, UPR 2940 CNRS, Grenoble, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Hazemann
authors.affiliation: Département de Chimie, Université de Montréal , Montréal, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Reber
authors.affiliation: Département de Chimie Physique, Université de Genève , 30 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hauser
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, F-69622, Villeurbanne, France.
authors.forename: Dominique
authors.identifier: 0000-0002-1831-7693
authors.initials: D
authors.lastname: Luneau