A5035016002- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Inorganic Fluorides and Related Compounds
- Crystal Structures and Properties
- Metal-Organic Frameworks: Synthesis and Applications
- Inorganic Chemistry and Materials
- Crystallography and molecular interactions
- Chemical Synthesis and Characterization
- Solid-state spectroscopy and crystallography
- Advanced Condensed Matter Physics
- Magnetism in coordination complexes
- Fluorine in Organic Chemistry
- Electrocatalysts for Energy Conversion
- Ammonia Synthesis and Nitrogen Reduction
- Methane Hydrates and Related Phenomena
- Advanced Battery Materials and Technologies
- Luminescence Properties of Advanced Materials
- Advancements in Battery Materials
- Synthesis and Catalytic Reactions
- Advanced Photocatalysis Techniques
- Synthetic Organic Chemistry Methods
- Asymmetric Synthesis and Catalysis
- Layered Double Hydroxides Synthesis and Applications
- Catalytic Processes in Materials Science
- Zeolite Catalysis and Synthesis
Institut des Molécules et Matériaux du Mans
2015-2024
Le Mans Université
2015-2024
Centre National de la Recherche Scientifique
2011-2024
Centre Hospitalier du Mans
2015-2020
Institute of Materials, Minerals and Mining
2015
Université Nantes Angers Le Mans
2014
University of Maine
2007-2014
Fluor (United States)
2002-2012
Centre de Gestion Scientifique
2004-2007
Laboratoire de Synthèse Organique
2006
The lamellar compound ${\mathrm{CuInP}}_{2}{\mathrm{S}}_{6}$ is presented as an unusual example of a collinear, two-sublattice ferrielectric system. Single-crystal x-ray diffraction used to study the thermal evolution polar character its structure. results are consistent with occurrence first-order, order-disorder transition at ${T}_{c}=315\mathrm{K}$ and provide indirect evidence for copper hopping motions. Estimates spontaneous polarization calculated various temperatures from atomic...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTParaelectric-Ferroelectric Transition in the Lamellar Thiophosphate CuInP2S6A. Simon, J. Ravez, V. Maisonneuve, C. Payen, and B. CajipeCite this: Chem. Mater. 1994, 6, 9, 1575–1580Publication Date (Print):September 1, 1994Publication History Published online1 May 2002Published inissue 1 September 1994https://pubs.acs.org/doi/10.1021/cm00045a016https://doi.org/10.1021/cm00045a016research-articleACS PublicationsRequest reuse permissionsArticle...
The development of electrocatalysts for the oxygen evolution reaction (OER) is one principal challenges in area renewable energy research. Within this context, mixed-metal oxides have recently emerged as highest performing OER catalysts. Their structural and compositional modification to further boost their activity crucial wide-spread use electrolysis technologies. In work, we investigated a series F-containing materials catalysts probe possible benefits high electronegativity fluoride...
Pure tysonite La1-xBaxF3-x solid solutions for x < 0.15 were prepared by state synthesis in a platinum tube under an azote atmosphere with subsequent quenching 0.07 ≤x 0.15. The studied X-ray, electron and neutron diffractions (19)F NMR impedance spectroscopy. evolution of the cell parameters obeying Vegard's rule was determined 0 x≤ atomic position accurately refined = 0.03, 0.10. chemical pressure induced large Ba(2+) cations leads to increase unit parameters. Fluorine environment...
Abstract ac electrical measurements are reported for the paraelectric phases of ferroelectric CuInP2S6 and antiferroelectric CuCrP2S6. A complex permittivity analysis confirms previous dielectric results CuInP2S6. Arrhenius behaviors with nearly identical activation energies were observed dc conductivities modulus relaxation frequencies. hopping mechanism Cu(I) transport in these materials is thus suggested.
Evolution with <italic>x</italic> of RT ionic conductivity RE<sub>1−x</sub>AE<sub>x</sub>F<sub>3−x</sub> showing that Ce<sub>1−x</sub>Sr<sub>x</sub>F<sub>3−x</sub> is the best F<sup>−</sup> tysonite conductor discussed.
The development of earth-abundant catalysts for the oxygen evolution reaction (OER) in acidic media represents a significant challenge context polymer electrolyte membrane (PEM)-based electrolysis. In this scope, transition metal oxides constitute an emerging alternative to Ir and Ru oxides. Notably, Mn are among few that have sufficient stability electrolytes, but their performance still lacks behind Ir/Ru To end, modification oxides' structure, crystallinity (or amorphous structure),...
We present a systematic survey of the structural chemistry crystalline hybrid fluorides. About hundred different metal fluoride building units are represented in these systems, predominantly as anionic moieties, ranging from simple tetrahedral or octahedral dimers to larger oligomeric species, complex chains, layers and, ultimately, three-dimensional frameworks. Although few compositional spaces have been moderately well explored and certain key features their chemistries understood,...
Pure tysonite Sm1–xCaxF3–x solid solutions for 0.05 ≤ x 0.17 have been prepared by the solid-state route. For first time, partial solution is investigated on basis of structural features and ionic conductivity measurements. Powder X-ray diffraction Rietveld refinements show an unexpected decrease hexagonal unit cell volume related to creation fluorine vacancies. The local environment F1, which mainly responsible conductivity, changes with Ca content: distortion F1(Sm,Ca)4 tetrahedral site...
The [4 + 2] acido-catalyzed heterocycloaddition between new β-substituted N-vinyl-1,3-oxazolidin-2-ones (with R' = Me, Ar, CH2 Ar) and β,γ-unsaturated α-ketoesters (R afforded heteroadducts with high levels of endo facial selectivities. A complete reversal differentiation was achieved by varying the Lewis acid, leading to stereoselective formation either endo-α or endo-β adducts.
This work suggests a simple and scalable synthetic route to prepare multimetallic oxyfluorides, without requiring high temperature, pressure, specific atmosphere (F2, N2, Ar, vacuum, etc.). For that, tunable compositions of Ni2+–Co2+–Fe3+-based oxyfluorides Co(1–x)/2Nix/2Fe0.5O0.5F1.5 have been prepared by calcination at moderate temperature under ambient air Co1–xNixFeF5(H2O)7 precursors, beforehand through coprecipitation room across the whole range solid solution (0 ≤ x 1). Structural...
Under smooth Eu(fod)(3)-catalyzed conditions, the inverse-electron demand hetero-Diels-Alder reactions between enantiopure N-vinyl-2-oxazolidinones 1a-f and representative beta,gamma-unsaturated alpha-ketoesters proceed with a high degree of endo facial diastereoselectivity. The elucidation stereostructure these adducts, performed by X-ray analysis or chemical correlation, shows that endo-selective cycloaddition process is facially controlled in favor (2S,4S)-adduct when starting from...
ZnAlF5·[TAZ], the first aluminium fluorinated metal–organic framework with cationic {Zn(1,2,4 triazole)}2+ linkers has been synthesized. The structure is accurately determined by coupling direct space methods on laboratory powder X-ray diffraction data solid-state nuclear magnetic resonance experiments and ab initio calculations, found to be analogous that of MIL-53(Al).
Abstract The transition to an antiferroelectric or ferroelectric phase in the lamellar compound CuMP2S6 (M= Cr In) is shown be triggered by appearance of ordered copper sublattice. Cu(I) ions CuCrP2S6, which are distributed over several sites at room temperature, freeze into intermediate quasi-antipolar state between 190 and 175K, then form array alternating up down dipoles below 150K. Evidence for these transitions were obtained using calorimetry, diffraction electric permittivity...
The synthesis and the electrochemical properties of iron hydroxyfluorides with an open structure, prepared from thermal decomposition Fe2+Fe3+F5(H2O)2 Fe2+Fe23+F8(H2O)2 under ambient air, are reported. combination thermogravimetric analyses, X-ray thermodiffraction (XRD), infrared spectroscopy has evidenced two unstable lacunar oxyfluorides that transform rapidly into air. Their formulations structural features have been determined powder XRD, Mössbauer spectrometry, pair distribution...
A novel two-step strategy to prepare amorphous oxyfluorides, containing both divalent and trivalent 3d-metals, as cathode materials for lithium batteries is presented. The first step involves the preparation of hydrated fluorides M2+M3+2F8(H2O)2 (M2+ = Mn, Fe, Co, Ni, Cu; M3+ V, Fe) by microwave-assisted solvothermal synthesis. Besides MnFe2F8(H2O)2 CuFe2F8(H2O)2 phases, three new compounds, Fe1.3V1.7F8(H2O)2, CoFe2F8(H2O)2, NiFe2F8(H2O)2, which are isostructural with Fe3F8(H2O)2, have been...