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Leblanc M.,CNRS Le Mans Institute of Molecules and Materials | Maisonneuve V.,CNRS Le Mans Institute of Molecules and Materials | Tressaud A.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux
Chemical Reviews | Year: 2015

Most important structural types of transition metal fluorocompounds and fluoride salts are reviewed. Besides solid-state or conventional reactions, several new processes are presented for a controlled elaboration of fluorides, such as subcritical solvothermal conditions, gaseous fluorination, reaction in ionic liquids, and low-temperature fluorine insertion. Because of the importance of inorganic metal fluorides in many innovating processes, the knowledge of their structural characteristics appears to be a decisive tool for getting a better understanding of the relevant parameters controlling their physical chemical properties. Source


Marre S.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Jensen K.F.,Massachusetts Institute of Technology
Chemical Society Reviews | Year: 2010

In this critical review, we present an overview of the current progress in synthesis of micro and nanostructures by using microfluidics techniques. Emphasis is placed on processes that can be realized on chip, such as polymerization, precipitation, sol-gel, thermolysis and multistep processes. Continuous flow, microfluidic systems show particular promise in controlling size, shape and size distribution of synthesized micro and nanoparticles. Moreover, the use of microfluidics expands the synthesis space (e.g., temperature, pressure, reagents) to conditions not easily accessed in conventional batch procedures and thus, opens new methods for the realization of complex engineered nanostructures and new materials systems. (187 references) © 2010 The Royal Society of Chemistry. Source


Matar S.F.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux
Progress in Solid State Chemistry | Year: 2012

A coherent overview of the physical and chemical properties of the family of transition metal hydrido complexes is addressed from ab initio through an exhaustive treatment from the solid state at different levels to the molecular state, taking a promising class of compounds for potential applications, the non-ahydrido complexes as an illustrative case study. A new chemical vision is presented, pertaining to structure-property relationships such as the different chemical behaviors of the tricapped trigonal prismatic {TH9} (T = Tc, Re) complex anions at the two distinct lattice sites. From energy differences different stability and binding of the Tc versus Re based compounds are underlined whereby the latter is found more tightly bonded. Such solid state results are also supported by calculations at the molecular level with larger infra-red frequencies within the ReH9 complex anion versus TcH9 corresponding to both bending and stretching T-H modes in agreement with experiment. Electronic density of states show both compounds to be insulating with large band gaps and narrow valence bands which are differentiated for the two sites of the transition element (T1 and T2): T1H9 sub-motifs at the corners and T2H9 ones forming a honeycomb arrangement as it is illustrated from the electron localization function (ELF) plots and chemical bonding. ELF maps are also significant of largely ionic 2K +(TH9) 2- compound within which covalent-like (TH9) 2- show electron localization on hydrogen and free electron behavior within the tricapped trigonal prism. © 2012 Elsevier Ltd. Source


Masquelier C.,CNRS Laboratory of Chemistry and Reactivity of Solids | Masquelier C.,French National Center for Scientific Research | Masquelier C.,CNRS RS2E | Croguennec L.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | And 2 more authors.
Chemical Reviews | Year: 2013

The concept of investigating three-dimensional frameworks based on the NASICON structure as hosts for reversible insertion/extraction of alkali cations (electrodes) arose in the mid 1980s mostly from concerns about possible stability or reactivity versus metallic Na (or Li) when used as solid electrolytes. The NASICON framework was used by Goodenough in the late 1980s as a very demonstrative example of the possibility for the chemist to elaborate electrode materials functioning at controlled operating voltages. Noticeably, these structures have been recently investigated by three independent groups as model compounds for the understanding of complex Li NMR signals in paramagnetic compounds, and useful insights into the activation energies for hopping between the lithium sites were provided. Source


Matar S.F.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux
Progress in Solid State Chemistry | Year: 2010

The review aims to provide a coverage of different classes of intermetallic systems, which have the ability of absorbing hydrogen in different amounts, like binary and ternary Laves phases and Haucke-type intermetallics. Such intermetallic hydrides are attractive for applied research as potential candidates for on-board vehicular use (engines, batteries, etc.). Focus is made here on the fundamental features regarding the physical and chemical properties obtained from the first-principles - ab initio, for a better understanding of the role played by inserted hydrogen. Beside establishing the equation of state, the binding energetics, the electronic band structure, the magneto-volume effects, the hyperfine field etc., we endeavor answering the relevant question raised by solid state chemistry: "where are the electrons?". This is approached through different schemes calling for a description of the chemical bonding, of the electron localization as well as the charge density mappings and the numerical Bader charge analysis scaling the iono-covalence of hydrogen within the lattice. For the sake of a complete scope we extend the studies to characteristics regarding the valence state changes in cerium based hydrided phases and the magnetism (spin-only, spin-orbit coupling, magnetic order of the ground state) in hydrogen modified ternary uranium intermetallics. © 2010 Elsevier Ltd. All rights reserved. Source

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