Les polyoxométallates, de nouveaux générateurs d'oxygène singulet

Les polyoxométallates, de nouveaux générateurs d'oxygène singulet PDF Author: Benjamin Pacaud
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Dans ce travail, nous nous sommes intéressés à la génération d'oxygène singulet (1O2), un oxydant sélectif permettant d'accéder à de nombreux intermédiaires oxygénés d'intérêt pour la chimie fine, par les polyoxométallates (POMs). Le criblage d'une série de POMs a permis de mettre en évidence pour la première fois, grâce à la détection spécifique de la luminescence infrarouge à 1270 nm, la formation de 1O2 par décomposition du peroxyde d'hydrogène catalysée par des POMs. Plus particulièrement, les polyoxoniobates se sont révélés très performants et ont fait l'objet d'une étude approfondie. Afin de pouvoir appliquer ces systèmes à l'oxydation de substrats hydrophobes, des sels d'alkylammonium ont été préparés, leur conférant ainsi des propriétés amphiphiles permettant d'envisager une catalyse interfaciale. Ainsi, nous avons montré que suivant la nature du solvant, en présence d'eau, des systèmes de microémulsions et d'émulsions de Pickering peuvent être obtenus. Leur intérêt en catalyse d'oxydation a été démontré, illustrant ainsi un nouvel exemple du concept "Pickering Interfacial Catalysis" (PIC) en émulsion. Par ailleurs, nous reportons également, pour la première fois, un nouveau surfactif catalytique équilibré (concept BCS) à base de POMs conduisant à la formation spontanée de systèmes de microémulsion triphasique en présence d'eau et d'huile. Enfin, les émulsions de Pickering catalytiques à base de cyclodextrines (CDs), développées précédemment au laboratoire, ont été reconsidérées sous l'angle de la catalyse interfaciale, ce qui nous a menés à proposer un nouveau concept de nanoparticules hybrides auto-assemblées cœur-écorce (CD@POM).

Les polyoxométallates, de nouveaux générateurs d'oxygène singulet

Les polyoxométallates, de nouveaux générateurs d'oxygène singulet PDF Author: Benjamin Pacaud
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
Dans ce travail, nous nous sommes intéressés à la génération d'oxygène singulet (1O2), un oxydant sélectif permettant d'accéder à de nombreux intermédiaires oxygénés d'intérêt pour la chimie fine, par les polyoxométallates (POMs). Le criblage d'une série de POMs a permis de mettre en évidence pour la première fois, grâce à la détection spécifique de la luminescence infrarouge à 1270 nm, la formation de 1O2 par décomposition du peroxyde d'hydrogène catalysée par des POMs. Plus particulièrement, les polyoxoniobates se sont révélés très performants et ont fait l'objet d'une étude approfondie. Afin de pouvoir appliquer ces systèmes à l'oxydation de substrats hydrophobes, des sels d'alkylammonium ont été préparés, leur conférant ainsi des propriétés amphiphiles permettant d'envisager une catalyse interfaciale. Ainsi, nous avons montré que suivant la nature du solvant, en présence d'eau, des systèmes de microémulsions et d'émulsions de Pickering peuvent être obtenus. Leur intérêt en catalyse d'oxydation a été démontré, illustrant ainsi un nouvel exemple du concept "Pickering Interfacial Catalysis" (PIC) en émulsion. Par ailleurs, nous reportons également, pour la première fois, un nouveau surfactif catalytique équilibré (concept BCS) à base de POMs conduisant à la formation spontanée de systèmes de microémulsion triphasique en présence d'eau et d'huile. Enfin, les émulsions de Pickering catalytiques à base de cyclodextrines (CDs), développées précédemment au laboratoire, ont été reconsidérées sous l'angle de la catalyse interfaciale, ce qui nous a menés à proposer un nouveau concept de nanoparticules hybrides auto-assemblées cœur-écorce (CD@POM).

CONTRIBUTION A L'ETUDE DE GENERATEURS CHIMIQUES D'OXYGENE SINGULET EN SOLUTION AQUEUSE

CONTRIBUTION A L'ETUDE DE GENERATEURS CHIMIQUES D'OXYGENE SINGULET EN SOLUTION AQUEUSE PDF Author: Bernadette Cazin
Publisher:
ISBN:
Category :
Languages : fr
Pages : 382

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Book Description
DEUX TYPES DE GENERATEURS CHIMIQUES D'OXYGENE SINGULET EN MILIEU AQUEUX ONT ETE ETUDIES, EN VUE D'APPLICATIONS DANS LES DOMAINES DE LA BIOLOGIE ET DE LA SYNTHESE ORGANIQUE. DES SUBSTRATS NAPHTALENIQUES, SOLUBLES DANS L'EAU, PERMETTENT DE STOCKER L'OXYGENE SINGULET EFFICACEMENT PUISQU'ILS FIXENT **(1)O::(2) ENTRE 0 ET 20**(O)C, ET SONT TOTALEMENT REGENERES PAR THERMOLYSE A 40**(O)C, EN LIBERANT L'OXYGENE DONT 50% EST A L'ETAT SINGULET. CE TYPE DE GENERATEUR CONSTITUE UNE SOURCE DOUCE ET "PROPRE" DE **(1)O::(2), PERMETTANT L'ETUDE DE L'INTERVENTION DE **(1)O::(2) DANS LES PROCESSUS BIOLOGIQUES. LA "DECOMPOSITION" DE H::(2)O::(2) PAR LES IONS MOLYBDATE CONSTITUE UN MOYEN POUR TRANSFORMER EFFICACEMENT H::(2)O::(2) EN OXYGENE SINGULET (100%). SUR DES CONSIDERATIONS CINETIQUES, NOUS AVONS MONTRE QUE LA DISMUTATION S'EFFECTUE VIA L'INTERMEDIAIRE PEROXO MOO::(6)**(2-). CETTE SOURCE MINERALE PEUT REMPLACER AVANTAGEUSEMENT LA PHOTOOXYGENATION ET PEUT ETRE UTILISEE POUR "CHARGER" EN **(1)O::(2) LES SUBSTRATS NAPHTALENIQUES DECRITS CI-DESSUS

Polyoxometalate Molecular Science

Polyoxometalate Molecular Science PDF Author: Juan J. Borrás-Almenar
Publisher: Springer Science & Business Media
ISBN: 9401000913
Category : Science
Languages : en
Pages : 473

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Book Description
Polyoxometalates (POMs) form a large, distinctive class of molecular inorganic compounds of unrivaled electronic versatility and structural variation, with impacts ranging from chemistry, catalysis, and materials science to biology, and medicine. This book covers the basic principles governing the structure, bonding and reactivity of these metal-oxygen cluster anions and the major developments in their molecular science. The book comprises three sections. The first covers areas ranging from topological principles via synthesis and stability to reactivity in solution. It also focuses on the physical methods currently used to extract information on the molecular and electronic structures as well as the physical properties of these clusters. The second part reviews different types of POMs, focusing on those systems that currently impact other areas of interest, such as supramolecular chemistry, nanochemistry and molecular magnetism. The third section is devoted to POM-based materials and their applications and prospects in catalysis and materials science.

A Chemist's Guide to Density Functional Theory

A Chemist's Guide to Density Functional Theory PDF Author: Wolfram Koch
Publisher: John Wiley & Sons
ISBN: 3527802819
Category : Science
Languages : en
Pages : 378

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Book Description
"Chemists familiar with conventional quantum mechanics will applaud and benefit greatly from this particularly instructive, thorough and clearly written exposition of density functional theory: its basis, concepts, terms, implementation, and performance in diverse applications. Users of DFT for structure, energy, and molecular property computations, as well as reaction mechanism studies, are guided to the optimum choices of the most effective methods. Well done!" Paul von Rague Schleyer "A conspicuous hole in the computational chemist's library is nicely filled by this book, which provides a wide-ranging and pragmatic view of the subject.[...It] should justifiably become the favorite text on the subject for practioneers who aim to use DFT to solve chemical problems." J. F. Stanton, J. Am. Chem. Soc. "The authors' aim is to guide the chemist through basic theoretical and related technical aspects of DFT at an easy-to-understand theoretical level. They succeed admirably." P. C. H. Mitchell, Appl. Organomet. Chem. "The authors have done an excellent service to the chemical community. [...] A Chemist's Guide to Density Functional Theory is exactly what the title suggests. It should be an invaluable source of insight and knowledge for many chemists using DFT approaches to solve chemical problems." M. Kaupp, Angew. Chem.

Nanozymes: Next Wave of Artificial Enzymes

Nanozymes: Next Wave of Artificial Enzymes PDF Author: Xiaoyu Wang
Publisher: Springer
ISBN: 3662530686
Category : Technology & Engineering
Languages : en
Pages : 134

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Book Description
This book describes the fundamental concepts, the latest developments and the outlook of the field of nanozymes (i.e., the catalytic nanomaterials with enzymatic characteristics). As one of today’s most exciting fields, nanozyme research lies at the interface of chemistry, biology, materials science and nanotechnology. Each of the book’s six chapters explores advances in nanozymes. Following an introduction to the rise of nanozymes research in the course of research on natural enzymes and artificial enzymes in Chapter 1, Chapters 2 through 5 discuss different nanomaterials used to mimic various natural enzymes, from carbon-based and metal-based nanomaterials to metal oxide-based nanomaterials and other nanomaterials. In each of these chapters, the nanomaterials’ enzyme mimetic activities, catalytic mechanisms and key applications are covered. In closing, Chapter 6 addresses the current challenges and outlines further directions for nanozymes. Presenting extensive information on nanozymes and supplemented with a wealth of color illustrations and tables, the book offers an ideal guide for readers from disparate areas, including analytical chemistry, materials science, nanoscience and nanotechnology, biomedical and clinical engineering, environmental science and engineering, green chemistry, and novel catalysis.

Polyoxometalate Chemistry

Polyoxometalate Chemistry PDF Author:
Publisher: Academic Press
ISBN: 0128111062
Category : Science
Languages : en
Pages : 360

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Book Description
Polyoxometalate Chemistry continues a long-running series that describes recent advances in scientific research, in particular, in the field of inorganic chemistry. Several highly regarded experts, mostly from academia, contribute on specific topics. The current issue focuses on recent advances in the development and application of polyoxometalate complexes in areas such as solution chemistry, self-organization, solar fuels, non-aqueous chemistry, spintronics, nanoscience and catalysis. - Presents a single monograph on recent developments in polyoxometalate chemistry as written by scientific leaders in this field - Concise and informative presentations cover a wide range of topics in this field of chemistry - Contains detailed literature references, enabling the reader to move on to the source of the reported work where more details can be found - Provides a solid presentation of a hard-cover book of excellent technical quality

Atomically Precise Metal Nanoclusters

Atomically Precise Metal Nanoclusters PDF Author: Zhikun Wu
Publisher: Morgan & Claypool Publishers
ISBN: 1636390250
Category : Science
Languages : en
Pages : 141

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Book Description
Atomically precise metal nanocluster research has emerged as a new frontier. This book serves as an introduction to metal nanoclusters protected by ligands. The authors have summarized the synthesis principles and methods, the characterization methods and new physicochemical properties, and some potential applications. By pursuing atomic precision, such nanocluster materials provide unprecedented opportunities for establishing precise relationships between the atomic-level structures and the properties. The book should be accessible to senior undergraduate and graduate students, researchers in various fields (e.g., chemistry, physics, materials, biomedicine, and engineering), R&D scientists, and science policy makers.

Luminescence Thermometry

Luminescence Thermometry PDF Author: Miroslav Dramićanin
Publisher: Woodhead Publishing
ISBN: 0081020309
Category : Technology & Engineering
Languages : en
Pages : 304

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Book Description
Luminescence Thermometry: Methods, Materials, and Applications presents the state-of-the art applications of luminescence thermometry, giving a detailed explanation of luminescence spectroscopic schemes for the read-out of temperature, while also describing the diverse materials that are capable of sensing temperature via luminescence. Chapters cover the fundamentals of temperature, traditional thermometers and their figures of merit, a concise description of optical thermometry methods, luminescence and instrumentation, and an explanation of the ways in which increases in temperature quench luminescence. Additional sections focus on materials utilized for luminescence thermometry and the broad range of applications for luminescence thermometry, including temperature measurement at the nanoscale and the application of multifunctional luminescent materials. - Provides an overview of luminescence thermometry applications, including high-temperature, biomedical, nanoscale and multifunctional - Delves into luminescence thermometry by materials group, including Rare-earth and transition Metal Ion Doped, Semiconductors, Quantum Dots and Organic materials - Gives a concise introduction of the latest methods of temperature measurement, including luminescence spectroscopic schemes and methods of analysis

Clusters – Contemporary Insight in Structure and Bonding

Clusters – Contemporary Insight in Structure and Bonding PDF Author: Stefanie Dehnen
Publisher: Springer
ISBN: 3319522965
Category : Science
Languages : en
Pages : 386

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Book Description
Chemical structure and bonding. The scope of the series spans the entire Periodic Table and addresses structure and bonding issues associated with all of the elements. It also focuses attention on new and developing areas of modern structural and theoretical chemistry such as nanostructures, molecular electronics, designed molecular solids, surfaces, metal clusters and supramolecular structures. Physical and spectroscopic techniques used to determine, examine and model structures fall within the purview of Structure and Bonding to the extent that the focus is on the scientific results obtained and not on specialist information concerning the techniques themselves. Issues associated with the development of bonding models and generalizations that illuminate the reactivity pathways and rates of chemical processes are also relevant. The individual volumes in the series are thematic. The goal of each volume is to give the reader, whether at a university or in industry, a comprehensive overview of an area where new insights are emerging that are of interest to a larger scientific audience.

Environmental Toxicology and Chemistry of Oxygen Species

Environmental Toxicology and Chemistry of Oxygen Species PDF Author: Irena Kruk
Publisher: Springer
ISBN: 3540495711
Category : Science
Languages : en
Pages : 275

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Book Description
Properties, sources of formation, reactions, and detection of oxygen species form the first part of this volume. Biochemical, toxicological and environmental aspects are dealt with in detail in the following chapters. This information provides the basis for a state-of-the-art understanding of the role of oxygen species in environmental pollution and as a health hazard.