0000000000018671

AUTHOR

Philippe Guionneau

0000-0003-4693-7715

showing 6 related works from this author

Spin crossover properties of the [Fe(PM-BiA)2(NCS)2] complex - phases I and II

2003

International audience; In the present review, we reexamine the photomagnetic properties of the [Fe(PM-BiA)2(NCS)2], cis-bis(thiocyanato)-bis[(N-2'-pyridylmethylene)-4-(aminobiphenyl)]iron(II), compound which exhibits, depending on the synthetic method, an exceptionally abrupt spin transition (phase I) with a very narrow hysteresis (T1/2O = 168 K and T1/2N = 173 K) or a gradual spin conversion (phase II) occurring at 190 K. In both cases, light irradiation in the tail of the 1MLCT-LS absorption band, at 830 nm, results in the population of the high-spin state according to the light-induced excited spin-state trapping (LIESST) effect. The capacity of a compound to retain the light-induced HS…

PopulationAnalytical chemistrySpin transition02 engineering and technology010402 general chemistry01 natural sciencesLIESSTSpin crossoverPhase (matter)educationKinetic relaxationeducation.field_of_studyCondensed matter physicsChemistryGeneral ChemistryIron(II)[CHIM.MATE]Chemical Sciences/Material chemistry021001 nanoscience & nanotechnologyPhotomagnetismSpin crossover0104 chemical sciencesKinetic relaxation.HysteresisExcited state0210 nano-technologyPhotomagnetism
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Synthesis and characterization of 4,6-O-butylidene-N-(2-hydroxybenzylidene)-beta-D-glucopyranosylamine: crystal structures of 4,6-O-butylidene-alpha-…

2002

4,6-O-Butylidene-N-(2-hydroxybenzylidene)-β-D-glucopyranosylamine was synthesized and characterized using analytical, spectral and single-crystal X-ray diffraction methods. 1H and 13C NMR studies showed the presence of the β-anomer, which has also been confirmed by the crystal structure. The molecular structure of this compound showed the presence of the tridentate ONO ligation-core. Both precursors, 4,6-O-butylidene-α-D-glucopyranose and 4,6-O-butylidene-β-D-glucopyranosylamine were characterized using single crystal X-ray diffraction. The α-anomeric nature of the former and β-anomeric nature of the latter were proposed based on 1H NMR studies and were confirmed by determining the crystal …

Models MolecularMagnetic Resonance SpectroscopyStereochemistryCharacterizationCyclohexane conformationCrystal structureGlycosyl amines010402 general chemistryCrystallography X-Ray01 natural sciencesBiochemistryAnalytical ChemistrySingle-crystal X-ray diffractionX-Ray DiffractionCarbohydrate ConformationMoleculePyransGlucosamineMolecular Structure010405 organic chemistryChemistryHydrogen bondOrganic ChemistryHydrogen BondingGeneral Medicine[CHIM.MATE]Chemical Sciences/Material chemistry3. Good health0104 chemical sciencesCrystallographyIntramolecular forceX-ray crystallographyProton NMRCrystal StructureSingle crystal
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Effect of metal dilution on the light-induced spin transition in [FexZn1-x(phen)2(NCS)2] (phen = 1,10-phenanthroline)

2008

International audience; The thermal and light-induced spin transitions in [FexZn1-x(phen)2(NCS)2] (phen = 1,10-phenantholine) have been investigated by magnetic susceptibility, photomagnetism and diffuse reflectivity measurements. These complexes display a thermal spin transition and undergo the light-induced excited spin state trapping (LIESST) effect at low temperatures. For each compound, the thermal spin transition temperature, T1/2, and the relaxation temperature of the photo-induced high-spin state, T(LIESST), have been systematically determined. It appears that T1/2 decreases with the metal dilution while T(LIESST) remains unchanged. This behaviour is discussed on the basis of the ki…

Spin statesPhenanthrolineAnalytical chemistrySpin transition010402 general chemistry01 natural sciencesLIESSTInorganic ChemistryMagnetic susceptibilitychemistry.chemical_compoundChemical compoundsDiffuse reflectivity measurements010405 organic chemistryMetalRelaxation (NMR)[CHIM.MATE]Chemical Sciences/Material chemistryPhotomagnetismMagnetic susceptibility3. Good health0104 chemical scienceschemistryExcited statePhysical chemistryCondensed Matter::Strongly Correlated ElectronsLIESSTPhotomagnetism
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Synthesis, crystal structure, magnetic properties and 57Fe Mossbauer spectroscopy of the new trinuclear [Fe3(4-(2'-hydroxyethyl)-1,2,4- triazole)6(H2…

2000

Hyetrz = 4-(2prime-hydroxyethyl)-1,2,4-triazole represents the first structurally characterized iron(II) spin crossover compound for which the structure has been solved above and below room temperature in both spin states. The compound crystallizes in the trigonal system, space group R3, a = 12.763(1) b= 67.144(1), V = 1684.3(1) 3, Z = 6 at 120K. At 330K the space group is retained and a = 13.0183(3) b=67.376(3), V = 1805.8(1) 3. The molecular structure consists of trinuclear FeII entities linked together by an unprecedented three-dimensional network of hydrogen bonds. This compound shows a gradual spin crossover behavior centered around room temperature, which has been followed by temperat…

Inorganic ChemistryCrystallographySpin statesHydrogen bondChemistrySpin crossoverMössbauer spectroscopyMoleculeCrystal structureSpectroscopyMagnetic susceptibility
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Mn(IV) and Co(III)-complexes of –OH-rich ligands possessing O2N, O3N and O4N cores: syntheses, characterization and crystal structures

2003

Mn(IV) and Co(III) complexes of tridentate –OH–rich ligands possessing O2N, O3N and O4N donor sets were synthesized, characterized and their structures were established by single crystal X-ray diffraction, where the binding core is O4N2. In the structurally characterized complexes, the coordination geometry about the metal ion was found to be distorted octahedral.

Manganese(IV) complexCrystal structure010402 general chemistry01 natural sciencesHydrogen bondsInorganic ChemistryMetalMagnetic momentMaterials ChemistryPhysical and Theoretical ChemistryCobalt(III) complexCoordination geometryMagnetic moment010405 organic chemistryHydrogen bondChemistryCrystal structure[CHIM.MATE]Chemical Sciences/Material chemistry0104 chemical sciences3. Good healthCharacterization (materials science)CrystallographyOctahedronvisual_artvisual_art.visual_art_mediumSingle crystal
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Experimental and Theoretical Studies on Magnetic Exchange in Silole-Bridged Diradicals.

2006

International audience; Five bis(tert-butylnitroxide) diradicals connected by a silole [2,5-R2-3,4-diphenylsilole; R = Me3CN(®O.bul.)Z; Z = p-C6H4 (7a), p-C6H4C6H4-p (7b), 1,4-naphthalenediyl (7c), m-C6H4 (7d)] or a thiophene [2,5-R2-thiophene; R = p-Me3CN(®O.bul.)C6H4 (12)] ring as a coupler were studied. Compd. 12 crystallizes in the orthorhombic space group Pna21 with a 20.752(5), b 5.826(5), and c 34.309(5) .ANG.. X-ray crystal structure detn., electronic spectroscopy, variable-temp. EPR spectroscopy, SQUID measurements and DFT computations (UB3LYP/6-31+G*) were used to study the mol. conformations and electronic spin coupling in this series of mols. Whereas compds. 7b, 7c, and 7d are q…

Models MolecularFree RadicalsSiloleCrystal structure010402 general chemistryRing (chemistry)01 natural sciencesDFTCatalysislaw.inventionchemistry.chemical_compoundNitroxide diradicalMagnetic interactionslawComputational chemistryThiopheneAntiferromagnetismOrganosilicon CompoundsSinglet stateTriplet stateElectron paramagnetic resonance010405 organic chemistryChemistry[CHIM.ORGA]Chemical Sciences/Organic chemistryOrganic ChemistryElectron Spin Resonance SpectroscopyGeneral Chemistry0104 chemical sciences[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryCrystallographyModels ChemicalButanesDiamagnetismEPR spectroscopy
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