Search

Your search keyword '"Institute of Materials Chemistry"' showing total 8 results
Start Over Author "Institute of Materials Chemistry" Language undetermined
8 results on '"Institute of Materials Chemistry"'

1. Efficient and accurate calculation of band gaps of halide perovskites with the Tran-Blaha modified Becke-Johnson potential

Author

Mikael Kepenekian, Xavier Rocquefelte, Fabien Tran, Gaëlle Bouder, Boubacar Traore, Claudine Katan, William Lafargue-Dit-Hauret, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Fonctions Optiques pour les Technologies de l'informatiON (Institut FOTON), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS), Institute of Materials Chemistry, Vienna University of Technology (TU Wien), 2017-A0010907682, Grand Équipement National De Calcul Intensif, 687008, Horizon 2020, F41, Austrian Science Fund, ANR-15-CE05-0018,TRANSHYPERO,Vers une compréhension des propriétés de transport électronique des cellules solaires basées sur les pérovskites hybrides(2015), European Project: 687008,H2020,H2020-FETOPEN-2014-2015-RIA,GOTSolar(2016), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)

Subjects
Materials science, hybrid organic-inorganic, Band gap, band structure, perovskites, Halide, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, Electronic structure, Large range, electronic structure, 021001 nanoscience & nanotechnology, DFT, 01 natural sciences, 7. Clean energy, Computational physics, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Pseudopotential, 0103 physical sciences, Density functional theory, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Hop (telecommunications), 010306 general physics, 0210 nano-technology, Electronic band structure
Abstract

This work was granted access to the HPC resources of [TGCC/CINES/IDRIS] under allocation 2017-A0010907682 made by GENCI.; International audience; We report on a reoptimization of the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential dedicated to the prediction of the band gaps of 3-dimensional (3D) and layered hybrid organic-inorganic perovskites (HOP) within pseudopotential-based density functional theory methods. These materials hold promise for future photovoltaic and optoelectronic applications. We begin by determining a set of parameters for 3D HOP optimized over a large range of materials. Then we consider the case of layered HOP. We design an empirical relationship that facilitates the prediction of band gaps of layered HOP with arbitrary interlayer molecular spacers with a computational cost considerably lower than more advanced methods like hybrid or GW. Our study also shows that substituting interlayer molecular chains of layered HOP with Cs atoms is an appealing and cost-effective route to band gap calculations. Finally, we discuss on the pitfalls and limitations of TB-mBJ for HOP, notably its tendency to overestimate the effective masses due to the narrowing of the band dispersions. We expect our results to extend the use of TB-mBJ for other low-dimensional materials.

Published
2019

2. Synthesis, Structures and Conformational Studies of 1,2-Dimethyl[2.10]metacyclophan-1-enes

Author

Shofiur Rahman, Thamina Akther, Taisuke Matsumoto, Carl Redshaw, Pierre Thuéry, Junji Tanaka, Paris E. Georghiou, Takehiko Yamato, Monarul Islam, Department of Applied Chemistry, Saga University [Japon], Memorial University of Newfoundland = Université Memorial de Terre-Neuve [St. John's, Canada] (MUN), Institute of Materials Chemistry and Engineering (Japan), Kyushu University, Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF) (LCMCE), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), University of Hull [United Kingdom], and Memorial University of Newfoundland [St. John's]

Subjects
[CHIM.ORGA]Chemical Sciences/Organic chemistry, 010405 organic chemistry, Stereochemistry, Hydrogen bond, Substituent, General Chemistry, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, Coupling reaction, 0104 chemical sciences, Acylation, chemistry.chemical_compound, chemistry, Intramolecular force, [CHIM.CRIS]Chemical Sciences/Cristallography, Boron tribromide, Hexamethylenetetramine, Demethylation
Abstract

International audience; A series of 1,2‐dimethyl[2.10]metacyclophan‐1‐enes (MCP‐1‐enes) containing different substituent groups has been synthesized to illustrate their conformational behavior. 4,22‐dimethoxy‐1,2‐dimethyl[2.10]MCP‐1‐ene 3 was synthesized by a Grignard coupling reaction, Friedel‐Crafts acylation reactions and McMurry coupling reaction from 1,10‐dibromodecane. The formation of 4,22‐dihydroxy‐1,2‐dimethyl[2.10]MCP‐1‐ene 4 was carried out by demethylation of compound 3 with boron tribromide at room temperature. The syn type conformation of 4 was characterized by X‐ray diffraction and was found to form both intramolecular and intermolecular hydrogen bonds between the two hydroxyl groups. From this reaction an interesting compound [10]tetrahydrobenzofuranophane 5 was afforded on prolonging the reaction time. 5,21‐diformyl‐4,22‐dihydroxy‐1,2‐dimethyl[2.10]MCP‐1‐ene 6 has been prepared from 4,22‐dihydroxy‐1,2‐dimethyl[2.10]MCP‐1‐ene 4 by using the Duff method in the presence of hexamethylenetetramine. Structural analysis by 1H NMR spectroscopy and X‐ray diffraction confirmed that both the solution and the crystalline state of compound 6 adopts an anti‐conformation which forms an intramolecular hydrogen bond between the formyl group and the hydroxyl group, which is an interesting finding for long carbon chain MCP compounds.

Published
2016

3. Aerogels from Cellulose Phosphates of Low Degree of Substitution: A TBAF·H2O/DMSO Based Approach

Author

Christian Bruno Schimper, Thomas Rosenau, Hubert Hettegger, Martin Wendland, Marie-Alexandra Neouze, Paul Pachschwoell, Falk Liebner, Jean-Marie Nedelec, University of Natural Resources and Life Sciences (BOKU), Vienna University of Technology, Institute of Materials Chemistry, Getreidemarkt 9/165, A-1060 Vienna, Institut de Chimie de Clermont-Ferrand (ICCF), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA), University Aveiro, Department of Chemistry and CICECO Aveiro Institute of Materials, Campus Universitário de Santiago, 3810-193 Aveiro, and Universität für Bodenkultur Wien = University of Natural Resources and Life [Vienne, Autriche] (BOKU)

Subjects
cellulose phosphate aerogel, Pharmaceutical Science, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Article, Phosphates, Analytical Chemistry, lcsh:QD241-441, chemistry.chemical_compound, tetrabutylammonium fluoride, Biopolymers, lcsh:Organic chemistry, supercritical carbon dioxide, Cellulose phosphate, interconnected porosity, Drug Discovery, [CHIM]Chemical Sciences, Dimethyl Sulfoxide, Physical and Theoretical Chemistry, Cellulose, Porosity, Dissolution, Supercritical carbon dioxide, Organic Chemistry, cellulose phosphate, Water, TBAF/DMSO, 021001 nanoscience & nanotechnology, Nanostructures, 0104 chemical sciences, Quaternary Ammonium Compounds, Solvent, Chemical engineering, chemistry, Chemistry (miscellaneous), Cellulosic ethanol, Solvents, engineering, Molecular Medicine, Biopolymer, 0210 nano-technology, Gels
Abstract

Biopolymer aerogels of appropriate open-porous morphology, nanotopology, surface chemistry, and mechanical properties can be promising cell scaffolding materials. Here, we report a facile approach towards the preparation of cellulose phosphate aerogels from two types of cellulosic source materials. Since high degrees of phosphorylation would afford water-soluble products inappropriate for cell scaffolding, products of low DSP (ca. 0.2) were prepared by a heterogeneous approach. Aiming at both i) full preservation of chemical integrity of cellulose during dissolution and ii) utilization of specific phase separation mechanisms upon coagulation of cellulose, TBAF&middot, H2O/DMSO was employed as a non-derivatizing solvent. Sequential dissolution of cellulose phosphates, casting, coagulation, solvent exchange, and scCO2 drying afforded lightweight, nano-porous aerogels. Compared to their non-derivatized counterparts, cellulose phosphate aerogels are less sensitive towards shrinking during solvent exchange. This is presumably due to electrostatic repulsion and translates into faster scCO2 drying. The low DSP values have no negative impact on pore size distribution, specific surface (SBET &le, 310 m2 g&minus, 1), porosity (&Pi, 95.5&ndash, 97 vol.%), or stiffness (E&rho, &le, 211 MPa cm3 g&minus, 1). Considering the sterilization capabilities of scCO2, existing templating opportunities to afford dual-porous scaffolds and the good hemocompatibility of phosphorylated cellulose, TBAF&middot, H2O/DMSO can be regarded a promising solvent system for the manufacture of cell scaffolding materials.

Published
2020

4. Emulsion and Foam Templating-Promising Routes to Tailor-Made Porous Polymers

Author

Cosima Stubenrauch, Wiebke Drenckhan, Alexander Bismarck, Angelika Menner, Institut für Physikalische Chemie [Stuttgart], Universität Stuttgart [Stuttgart], Institute of Materials Chemistry and Research, University of Vienna, Institut Charles Sadron (ICS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
chemistry.chemical_classification, Materials science, Dispersity, Nanotechnology, 02 engineering and technology, General Chemistry, Polymer, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Bridge (interpersonal), Catalysis, 0104 chemical sciences, Template, chemistry, Emulsion, 0210 nano-technology, Porosity
Abstract

International audience; Emulsions, foams, and foamed emulsions have been used successfully as templates for the synthesis of macroporous polymers. Based on this knowledge this Minireview presents strategies to use, optimise, and upscale these templating methods to synthesise tailor‐made porous polymers. The uniqueness of such polymers lies in the ability to tailor their structures and, therefore, their properties. However, systematic studies on structure–property relations are lacking mainly because the templating scientific community is “split into two”: the polydisperse and monodisperse camps. Thus, it is time to build a bridge between the camps, that is, to synthesise porous polymers with very different structures from the same precursors to determine the relationship between the structure and the properties.

Published
2018

5. Reproducibility in density functional theory calculations of solids

Author

Patrik Thunström, Ulrike Nitzsche, Georg Kresse, Stefan Goedecker, Stewart J. Clark, Claudia Draxl, José A. Flores-Livas, Martin Schlipf, Xavier Gonze, P. J. Hasnip, Klaus Koepernik, Marc Torrent, Matthias Scheffler, F. Jollet, Alexandre Tkatchenko, Martijn Marsman, Jonathan R. Yates, Volker Blum, Paolo Giannozzi, Gustav Bihlmayer, D. R. Hamann, Oscar Grånäs, Torbjörn Björkman, Nicola Marzari, Matteo Giantomassi, Keith Refson, Yaroslav Kvashnin, Natalie Holzwarth, Michiel van Setten, Guo-Xu Zhang, Taisuke Ozaki, Stefano de Gironcoli, Ivano E. Castelli, Stefaan Cottenier, Chris J. Pickard, J. K. Dewhurst, David Vanderbilt, Manuel Richter, Thierry Deutsch, Veronique Van Speybroeck, Gian-Marco Rignanese, Ward Poelmans, Kurt Lejaeghere, Sangeeta Sharma, Damien Caliste, Lorenzo Paulatto, Igor Di Marco, Francesca Tavazza, Emine Kucukbenli, Peter Blaha, Francois Gygi, Stefan Blügel, Andrea Dal Corso, Dominik B. Jochym, Lars Nordström, Karlheinz Schwarz, Luigi Genovese, Santanu Saha, Diana Iusan, Matt Probert, John M. Wills, Andris Gulans, Daniel M. Jones, E. K. U. Gross, Inka L. M. Locht, Sven Lubeck, Marcin Dulak, Kevin F. Garrity, Olle Eriksson, Center for molecular modeling, Universiteit Gent = Ghent University (UGENT), Institute of Materials Chemistry, Vienna University of Technology (TU Wien), Laboratory of Atomistic Simulation (LSIM ), Modélisation et Exploration des Matériaux (MEM), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Physics [Durham], Durham University, Department of Physics and Astronomy [Uppsala], Uppsala University, Max-Planck-Institut für Mikrostrukturphysik (MPI-HALLE), Max-Planck-Gesellschaft, University of Udine Italy, University of Basel (Unibas), Institut de la matière condensée et des nanosciences / Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain = Catholic University of Louvain (UCL), University of Oxford, Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Department of Materials Science and Metallurgy [Cambridge University] (DMSM), University of Cambridge [UK] (CAM), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), European Project: 329386,EC:FP7:PEOPLE,FP7-PEOPLE-2012-IEF,EXMAMA(2013), European Project: 676580,H2020,H2020-EINFRA-2015-1,NoMaD(2015), Universiteit Gent = Ghent University [Belgium] (UGENT), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), University of Oxford [Oxford], Pickard, Christopher [0000-0002-9684-5432], and Apollo - University of Cambridge Repository

Subjects
REGULAR APPROXIMATIONS, DFT, first principles, delta test, Materialkemi, 02 engineering and technology, generalized-gradient approximation, augmented-wave method, regular approximations, pseudopotentials, silicon, state, 1st-principles, crystals, science, energy, 01 natural sciences, 1st-Principles, ENERGY, Materials Chemistry, Statistical physics, Pseudopotentials, validation, [PHYS]Physics [physics], Physics, Multidisciplinary, 0104 Statistics, SCIENCE, Condensed Matter Physics, 021001 nanoscience & nanotechnology, STATE, Generalized-Gradient Approximation, Density functional theory, 0210 nano-technology, Den kondenserade materiens fysik, Theory of Condensed Matter, Augmented-Wave Method, 010402 general chemistry, AUGMENTED-WAVE METHOD, Settore FIS/03 - Fisica della Materia, Theoretical physics, Generalized gradient, Clinical Research, SILICON, Basis set, GENERALIZED-GRADIENT APPROXIMATION, Reproducibility, ta114, 1ST-PRINCIPLES, PSEUDOPOTENTIALS, 0104 chemical sciences, CRYSTALS, Formalism (philosophy of mathematics), Physics and Astronomy, numerical simulation, Pairwise comparison
Abstract

NTRODUCTION The reproducibility of results is one of the underlying principles of science. An observation can only be accepted by the scientific community when it can be confirmed by independent studies. However, reproducibility does not come easily. Recent works have painfully exposed cases where previous conclusions were not upheld. The scrutiny of the scientific community has also turned to research involving computer programs, finding that reproducibility depends more strongly on implementation than commonly thought. These problems are especially relevant for property predictions of crystals and molecules, which hinge on precise computer implementations of the governing equation of quantum physics. RATIONALE This work focuses on density functional theory (DFT), a particularly popular quantum method for both academic and industrial applications. More than 15,000 DFT papers are published each year, and DFT is now increasingly used in an automated fashion to build large databases or apply multiscale techniques with limited human supervision. Therefore, the reproducibility of DFT results underlies the scientific credibility of a substantial fraction of current work in the natural and engineering sciences. A plethora of DFT computer codes are available, many of them differing considerably in their details of implementation, and each yielding a certain “precision” relative to other codes. How is one to decide for more than a few simple cases which code predicts the correct result, and which does not? We devised a procedure to assess the precision of DFT methods and used this to demonstrate reproducibility among many of the most widely used DFT codes. The essential part of this assessment is a pairwise comparison of a wide range of methods with respect to their predictions of the equations of state of the elemental crystals. This effort required the combined expertise of a large group of code developers and expert users. RESULTS We calculated equation-of-state data for four classes of DFT implementations, totaling 40 methods. Most codes agree very well, with pairwise differences that are comparable to those between different high-precision experiments. Even in the case of pseudization approaches, which largely depend on the atomic potentials used, a similar precision can be obtained as when using the full potential. The remaining deviations are due to subtle effects, such as specific numerical implementations or the treatment of relativistic terms. CONCLUSION Our work demonstrates that the precision of DFT implementations can be determined, even in the absence of one absolute reference code. Although this was not the case 5 to 10 years ago, most of the commonly used codes and methods are now found to predict essentially identical results. The established precision of DFT codes not only ensures the reproducibility of DFT predictions but also puts several past and future developments on a firmer footing. Any newly developed methodology can now be tested against the benchmark to verify whether it reaches the same level of precision. New DFT applications can be shown to have used a sufficiently precise method. Moreover, high-precision DFT calculations are essential for developing improvements to DFT methodology, such as new density functionals, which may further increase the predictive power of the simulations.

Published
2016

6. Structure evolution of layered double hydroxides activated by ultrasound induced reconstruction

Author

R.J. Chimentão, Didier Tichit, Karin Föttinger, F. Gispert-Guirado, Mayra G. Álvarez, Noelia Barrabés, Francesc Medina, Evgeny Kleymenov, Enginyeria Química, Universitat Rovira i Virgili., EMaS-Centro de Investigación en Ingeniería de Materiales y micro/nano Sistemas, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Institute of Materials Chemistry, Vienna University of Technology (TU Wien), Servei de Recursos Científics i Tècnics, Paul Scherrer Institute (PSI), Spanish Government's Ministry of Science and Innovation (project CTQ2006-08196 and CTQ2008-03043-E, ACENET), and CSIC-MICINN financial support to the Experiment 25-01-775 at the Splinebeamline at the ESRF

Subjects
education.field_of_study, Materials science, Sonication, Thermal decomposition, Population, Inorganic chemistry, Layered double hydroxides, Geology, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, engineering.material, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, XANES, 0104 chemical sciences, Crystallinity, Geochemistry and Petrology, Phase (matter), engineering, Crystallite, 0210 nano-technology, education
Abstract

International audience; Reconstruction of mixed oxides resulting from the thermal decomposition at 723 K of ZnAl and ZnMgAl layered double hydroxides (LDHs) has been studied performing mechanical stirring or ultrasonic treatments for different periods of time in aqueous media. Thesematerialswere fully characterized by several physico-chemicalmethods including powder X-Ray diffraction and Rietveld refinements, XANES and XASF spectroscopies. The results show that the crystallinity increases in the LDH samples after the reconstruction. The crystallite sizes of the reconstructed LDHs increase in comparison to the as-prepared LDHs and this effect is improved upon ultrasound treatments. Moreover, reconstructed samples did not completely recover the original structure and ZnO phase was formed at the expense of an amorphous phase present in the as-prepared LDH. The application of ultrasound favors the formation of ZnO. Incorporation ofMg as ternary cation to obtain Mg/Zn/Al LDH decreases the crystallinity and leads to more disordered materials. The Mg/Zn/Al LDHs present lower amount of amorphous phase than ZnAl LDHs which also decreases in the reconstructed samples. But, in contrast to the behavior observed for Zn/Al, ultrasonication alters the crystallinity and increase of the amount of amorphous phasewhen sonication timeincreases. The basicity (number, strength and nature of sites) increases after reconstruction of themixed oxides into the LDH structures as well as with the sonication time; while the opposite trend was observed for the acid sites. Moreover the basicity is greatly enhanced upon introduction ofMg in the LDH. The changes in the population of acid-base sites affect the behavior of the catalysts in the carbonylation of glycerol.

Published
2013

7. One-electron oxidized copper(II) salophen complexes: phenoxyl versus diiminobenzene radical species

Author

Fumito Tani, Benoit Baptiste, Hervé Vezin, Olivier Jarjayes, Fabrice Thomas, Christian Philouze, Kazuaki Tsukidate, Amélie Kochem, Yuichi Shimazaki, Maylis Orio, Département de Chimie Moléculaire - Chimie Inorganique Redox Biomimétique (DCM - CIRE), Département de Chimie Moléculaire (DCM), Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), College of Science, Ibaraki University Bunkyo, Institute for Materials Chemistry and Engineering, Kyushu University [Fukuoka], Département de Chimie Moléculaire - Chimie Inorganique Redox (DCM - CIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Kyushu University

Subjects
Free Radicals, Radical, chemistry.chemical_element, Electrons, Electron, salophen, 010402 general chemistry, Photochemistry, Crystallography, X-Ray, 01 natural sciences, Catalysis, Polymer chemistry, Organometallic Compounds, Redox active, Molecular Structure, 010405 organic chemistry, Organic Chemistry, Benzene, General Chemistry, radicals, Copper, Salicylates, 3. Good health, 0104 chemical sciences, X-ray diffraction, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, chemistry, X-ray crystallography, density functional calculations, Quantum Theory, Imines, Oxidation-Reduction
Abstract

Where is the radical? The π-system of the diiminobenzene bridge adds a putative oxidation site to prophenoxyl copper(II) salophen complexes. It is shown that the bridge is effectively redox active and that the radical site (phenoxyl vs. diiminobenzene bridge) in the above cations is tuned by selective methoxy substitution (see figure).

Published
2011

8. Short-range magnetic order and temperature-dependent properties of cupric oxide

Author

Antoine Villesuzanne, Karlheinz Schwarz, Stéphane Jobic, Fabien Tran, Peter Blaha, Xavier Rocquefelte, Myung-Hwan Whangbo, Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), Department of Chemistry (NCSU), North Carolina State University [Raleigh] (NC State), University of North Carolina System (UNC)-University of North Carolina System (UNC), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Université de Bordeaux (UB), Institute of Materials Chemistry, Vienna University of Technology (TU Wien), and Department of Chemistry, North Carolina Raleigh

Subjects
Work (thermodynamics), Materials science, Band gap, Oxide, Condensed matter, Inorganic compounds, FOS: Physical sciences, 02 engineering and technology, Electronic structure, 01 natural sciences, DFT, chemistry.chemical_compound, Condensed Matter - Strongly Correlated Electrons, Condensed Matter::Superconductivity, 0103 physical sciences, General Materials Science, 010306 general physics, Spin (physics), Electrical, Range (particle radiation), Condensed Matter - Materials Science, Condensed matter physics, Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Oxides, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, magnetic and optical, chemistry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Density functional theory, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology, Nuclear quadrupole resonance
Abstract

The temperature dependence of the optical and magnetic properties of CuO were examined by means of hybrid density functional theory calculations. Our work shows that the spin exchange interactions in CuO are neither fully one-dimensional nor fully three-dimensional. The large temperature dependence of the optical band gap and the 63Cu nuclear quadrupole resonance frequency of CuO originate from the combined effect of a strong coupling between the spin order and the electronic structure and the progressive appearance of short-range order with temperature., Comment: 22 pages, 4 figure, 2 tables, letters submitted in Europhysics Letters

Published
2011

Catalog

Books, media, physical & digital resources
See catalog results