245 results on '"Platine"'
Search Results
2. Effets des Raidisseurs de Platine d'about sur les Assemblages Boulonnes de type Poteau-Poutre
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MERAD BOUDIA, Sofiane Boumedyen, BOUMECHRA, Nadir, MISSOUM, Abdelghani, BOUCHAIR, Abdelhamid, Laboratoire Eau et Ouvrages dans Leur Environnement (EOLE), Université de Tlemcen, Université Abdelhamid Ibn Badis de Mostaganem, Institut Pascal (IP), SIGMA Clermont (SIGMA Clermont)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), Université Clermont Auvergne (UCA), and Centre National de la Recherche Scientifique (CNRS)
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Extended ,Bolts ,End-Plate ,Assemblages ,Platine ,Raidisseurs ,Joints ,[SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures ,Stiffeners ,Boulons ,Débord - Abstract
International audience; Le présent papier a pour but d'étudier le comportement mécanique des assemblages métalliques poteau poutre boulonnés par platine d'about raidie à ses débords sous à un moment de flexion. L'étude est basée sur un modèle en éléments finis qui tient compte des non-linéarités géométriques, matérielles et celles du contact entre les éléments. Les résultats du modèle numérique ont été validés sur la base des résultats expérimentaux disponibles dans la littérature et comparés avec le modèle analytique proposé par l'Eurocode 3 et. Une étude paramétrique est menée afin de mettre en évidence l'effet des raidisseurs de platine d'about en zone tendue et comprimée de l'assemblage.
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- 2023
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3. An open, scalable system for long-term environmental monitoring of buildings
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The monitoring of buildings has become increasingly popular in recent years. Especially municipal buildings such as schools often receive media attention because of issues with indoor air quality. Unfortunately, much of the sensor-hardware used for environmental monitoring of indoor spaces is proprietary, making it difficult or impossible to replace. In addition, many vendors support their hardware only for a limited time and do not offer the possibility of transferring data to a central location for later analysis. Those that do are restricted or expensive. This thesis aims to develop a system for the long-term environmental monitoring of buildings. The utilized hardware is open source and inexpensive. We have developed a circuit board that provides plug-and-play capabilities to add sensors to the system for non-technical personnel. Further, the software is open-source and offers extensive configuration options via a web application to swap sensors, configure rooms, data loggers, or their used sensors. Users can export sensor data through a GUI or automatically via an API. For the evaluation, we consider the requirements for municipal buildings in the context of a school building in Stams (Tyrol), where the system is actively in use. Additionally, we describe how we implemented the requirements., author Thomas Tschol, Masterarbeit University Innsbruck 2022
- Published
- 2022
4. An open, scalable system for long-term environmental monitoring of buildings
- Abstract
The monitoring of buildings has become increasingly popular in recent years. Especially municipal buildings such as schools often receive media attention because of issues with indoor air quality. Unfortunately, much of the sensor-hardware used for environmental monitoring of indoor spaces is proprietary, making it difficult or impossible to replace. In addition, many vendors support their hardware only for a limited time and do not offer the possibility of transferring data to a central location for later analysis. Those that do are restricted or expensive. This thesis aims to develop a system for the long-term environmental monitoring of buildings. The utilized hardware is open source and inexpensive. We have developed a circuit board that provides plug-and-play capabilities to add sensors to the system for non-technical personnel. Further, the software is open-source and offers extensive configuration options via a web application to swap sensors, configure rooms, data loggers, or their used sensors. Users can export sensor data through a GUI or automatically via an API. For the evaluation, we consider the requirements for municipal buildings in the context of a school building in Stams (Tyrol), where the system is actively in use. Additionally, we describe how we implemented the requirements., author Thomas Tschol, Masterarbeit University Innsbruck 2022
- Published
- 2022
5. Influence of the formulation of catalysts deposited on cordierite monoliths for acetic acid oxidation.
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Sedjame, Henri-Joël, Brahmi, Rachid, Lafaye, Gwendoline, Jr.Barbier, Jacques, and Fontaine, Céline
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CORDIERITE , *CATALYTIC oxidation , *MONOLITHIC reactors , *CHEMISORPTION , *X-ray diffraction , *ACETIC acid - Abstract
Monolithic catalysts are prepared by washcoating cordierite monoliths with different sols (Pt/Al 2 O 3 , Pt/CeO 2 , Pt/ZrO 2 , Pt/Al 2 O 3 CeO 2 , Pt/Al 2 O 3 ZrO 2 , and Pt/CeO 2 ZrO 2 ). These sols are prepared by a sol–gel process and characterized by specific surface area ( S BET ), inductively coupled plasma, hydrogen chemisorption, high-resolution transmission electron microscopy, field emission scanning electron microscopy, oxygen storage capacity, X-ray diffraction, temperature-programmed reduction, CO 2 chemisorption, and the model reaction of 3,3-dimethylbutene isomerization. The catalytic performances of the monolithic catalysts are then evaluated for the acetic acid oxidation. The nature of catalyst coating has been found to influence the adherence with the cordierite monolith and the presence of cerium in the catalyst appears to increase the adherence of the latter. Pt/CeO 2 , Pt/Al 2 O 3 CeO 2 , and Pt/CeO 2 ZrO 2 are found to be the most reducible catalysts (oxygen storage capacity and temperature-programmed reduction) and to have the lowest acidities (3,3-dimethylbutene isomerization). CO 2 chemisorption shows that these catalysts possess a good basicity. From the relation established between the catalytic activity and the redox and acid–base properties it has been concluded that the reducibility is the key factor for a good catalytic activity although the basicity has a significant influence on the catalytic performance. [ABSTRACT FROM AUTHOR]
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- 2018
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6. Nanoscale thin films of niobium oxide on platinum surfaces: creating a platform for optimizing material composition and electrochemical stability.
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Eastcott, Jennie I., Parakh, Abhinav, Paul, Michael T.Y., Lee, Austin W.H., Bilton, Matthew W., and Gates, Byron D.
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NANOFILMS , *NIOBIUM oxide , *PLATINUM surfaces , *OXYGEN reduction , *PROTON exchange membrane fuel cells - Abstract
A nanoscale thin film of niobium oxide on a platinum substrate was evaluated for its influence on the electronic and chemical properties of the underlying platinum towards the oxygen reduction reaction with applications to proton exchange membrane fuel cells. The nanoscale thin film of niobium oxide was deposited using atomic layer deposition onto the platinum substrate. A film of niobium oxide is a chemically stable and electronically insulating material that can be used to prevent corrosion and electrochemical degradation when layers are several nanometers thick. These layers can be insulating if sufficiently thick and may not be sufficient to protect the platinum from corrosion if too thin. An ∼3 nm thin film of niobium oxide was fabricated on the platinum surface to determine its influence on the electronic and chemical properties at the interface of these materials. The atomic layer deposition process enabled a precise control over the material composition, structure, and layer thickness. The niobium oxide film was evaluated using cyclic voltammetry and electrochemical impedance spectroscopy to evaluate whether a balance could be found between the inhibition of platinum degradation and electronic insulation of the platinum for use in proton exchange membrane fuel cells. The 3 nm thin niobium oxide film was found to be sufficiently thin to permit electronic conductivity while reducing the incidence of platinum dissolution. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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7. Colloidal synthesis of Pt-In bimetallic nanoparticles for propane dehydrogenation.
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Wang, Xuchun, Yang, Di, Xu, Yong, Zhong, Jun, and Zhang, Qiao
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NANOPARTICLES , *SYNCHROTRONS , *PARTICLE accelerators , *INDUSTRIAL applications , *BIMETALLIC catalysts - Abstract
Recently, Pt-based bimetallic nanoparticles have drawn much attention because of their great catalytic performance and wide applications in diverse fields. In this work, we report that bimetallic Pt-In nanoparticles with uniform size distribution and controllable composition can be synthesized through a one-step, facile colloidal approach. Various characterization tools such as XRD, TEM, XPS, and synchrotron techniques have been used to characterize the as-obtained nanoparticles. It is demonstrated that the Pt and In elements are homogeneously distributed in the whole nanoparticle. The bimetallic Pt-In nanoparticles have shown great catalytic performance, including high activity, high selectivity, and high stability, for the propane dehydrogenation reaction to produce propene, one of the most important chemicals. The excellent catalytic performance makes Pt-In bimetallic nanoparticles promising catalysts in future industrial application. [ABSTRACT FROM AUTHOR]
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- 2017
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8. Impact du soufre sur le transport des platinoïdes par les fluides hydrothermaux
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Laskar, Clement, Géosciences Environnement Toulouse (GET), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier - Toulouse III, and Gleb Pokrovski
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Ressources minérales ,Molecular dynamics ,Constantes de stabilité ,Sulfite complexes ,Platine ,Dynamique moléculaire ,Molybdène ,Hydrothermal fluid ,Stability constants ,Géochimie expérimentale ,Platinum ,Spectroscopie d'absorption X ,Molybdenum ,Solubilité ,Mineral resources ,X-ray absorption spectroscopy ,Experimental geochemistry ,Métaux critiques ,Fluide hydrothermal ,Thermodynamique ,Critical metals ,Solubility ,Complexes sulfurés ,Thermodynamics ,Palladium ,[SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy - Abstract
The goal of this thesis is to better quantify the role of sulfur-bearing hydrothermal fluids in the transport of critical chalcophile metals such as platinoids (PGE). Knowledge of the chemical complexes formed between these metals and sulfur ligands is essential to predict the solubility and transport of these metals as a function of fluid composition (e.g., sulfur concentration and speciation, pH, fO2) over a wide range of temperatures and pressures in the Earth's crust. However, this knowledge yet remains elusive. In particular, the exact impact of both traditional major sulfide ligands (HS-/H2S) and the trisulfur radical ion S3•- recently discovered at hydrothermal conditions on the mobilization of these metals, remains both inconsistent and controversial. To fill this gap, in this work we use three complementary approaches: i) hydrothermal reactor solubility experiments under controlled conditions; ii) in situ synchrotron X-ray absorption spectroscopy (XAS) measurements; and iii) structure and stability modeling of complexes by thermodynamic and molecular dynamics methods, to quantify, systematically for the first time, the speciation and solubility of Pt and Pd in H2S/HS/S3--bearing hydrothermal fluids. The major results of our work is the demonstration for the first time of the formation of two key complexes responsible for the transport of Pt and Pd: (Pt/Pd)(HS)42- in sulfide solutions and (Pt/Pd)(HS)2(S3)22- in sulfide-sulfate solutions, at temperatures between 50 and 300 °C and pressures between up to at least 1 kbar. These new results allowed us to generate thermodynamic stability constants for these complexes, and to use them to predict the solubility of Pt- and Pd-bearing sulfide solid phases (PtS, PtS2, PdS). Our predictions show that the transport of platinoids has been largely underestimated, by a factor of at least 1000 to 10000 in previous studies because they all ignored the role of the S3•- ion. In summary, our results have elucidated, for the first time and in a systematic manner, the nature and stability of the major forms of platinum and palladium in S-bearing geological fluids, and have better quantified the action of sulfur and its radicals on critical metals transfers in the lithosphere. The results of our work have applications for metallogeny and mineral resources, geochemical tracing and noble metal based nanotechnologies.; Le but de ce travail de thèse est de mieux quantifier le rôle des fluides hydrothermaux porteurs de soufre dans le transport de métaux critiques chalcophiles comme les platinoïdes (PGE). La connaissance des complexes chimiques qu'ils forment avec les ligands soufrés est essentielle pour prédire la solubilité et le transport de ces métaux en fonction de la composition chimique du fluide (e.g., concentration et spéciation de soufre, pH, fO2) dans une large gamme de température et pression de la croûte terrestre. Toutefois cette connaissance est encore très incomplète et parfois contradictoire. En particulier, l'impact sur la mobilisation de ces métaux de nouvelles formes de soufre, les ions radicalaires trisulfures S3•-, récemment découverts dans les conditions hydrothermales, demeure inconnu. Pour combler cette lacune, dans ce travail nous avons mis en œuvre trois approches complémentaires : i) expériences de solubilité en réacteur hydrothermal en conditions contrôlées; ii) mesures par spectroscopie d'absorption de rayons X in situ (XAS) sur synchrotron; et iii) modélisation de structure et de stabilité de complexes par méthodes thermodynamiques et de dynamique moléculaire. Le principal résultat de ce travail est la mise en évidence, pour la première fois, de la formation de deux complexes majeurs responsables du transport de Pt et Pd, (Pt/Pd)(HS)42- dans des solutions sulfurées et (Pt/Pd)(HS)2(S3)22- dans des solutions contenant sulfate et sulfure, à des températures entre 50 et 300 °C et à des pressions jusqu'à 1 kbar. Ces nouveaux résultats ont permis de générer les constantes thermodynamiques de réactions de formation de ces complexes. Ces constantes ont été utilisées pour prédire la solubilité des sulfures de platinoïdes (PtS, PtS2, PdS). Nos prédictions montrent que le transport des platinoïdes a été largement sous-estimé, d'un facteur au moins 1000 à 10 000, dans les travaux antérieurs qui ont tous ignoré le rôle de l'ion S3•-. En résumé, nos résultats ont permis d'élucider, pour la première fois et de manière systématique, la nature et la stabilité des principales formes du platine et du palladium dans les fluides géologiques, et de mieux quantifier l'action du soufre et de ses radicaux sur les transferts de matière dans la lithosphère. Ces résultats ont des applications à la fois pour la métallogénie et les ressources minérales, le traçage géochimique ou encore les nanotechnologies utilisant ces métaux.
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- 2022
9. Synthesis, characterization, and anticancer properties of iminophosphineplatinum(II) complexes containing boronate esters.
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St-Coeur, Patrick-Denis, Kinley, Samantha, Vogels, Christopher M., Decken, Andreas, Jr. Morin, Pier, and Westcott, Stephen A.
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IMINO compounds , *PLATINUM , *ANTINEOPLASTIC agents , *BORON , *BORONIC esters , *GLIOMAS - Abstract
Three new iminophosphines containing pinacol-derived boronate esters have been prepared and ligated to dichloridoplatinum(II) fragments. All compounds have been characterized fully, including an X-ray diffraction study carried out for the platinum complex 8, which is derived from 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline. These three new platinum complexes, along with the non-boron containing control, have been examined for their initial cytotoxic properties against two glioma cell lines using the MTT method. [ABSTRACT FROM AUTHOR]
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- 2017
- Full Text
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10. Développement d’un réacteur électro-membranaire utilisant l'électrolyse pour la production d'hydroxyde de lithium
- Author
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Faral, Manon and Dollé, Mickaël
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Optimization ,Design of experiment ,Nafion ,Anode dépolarisée à l’hydrogène ,Batterie Li-ion ,Électrolyse membranaire ,Cinétique de réaction électrochimique ,Platine ,Membrane electrolysis ,Réaction d’oxydation de l’hydrogène ,Electrochemical reaction kinetics ,Li-ion battery ,Hydrogen depolarized anode ,Optimisation ,Hydrogen oxidation reaction ,Plan d’expérience ,Platinum - Abstract
Au cours des dernières années, le développement des batteries Li-ion a révolutionné nos modes de vie. Compte tenu de la croissance exponentielle en batteries, le besoin se répercute sur les matériaux de base, qui sont entre autres, synthétisés à partir de sels de lithium de haute pureté. Nemaska Lithium, une entreprise partenaire du projet, est reconnue en tant que nouveau producteur d’hydroxyde de lithium, par l’entremise d’un procédé électromembranaire breveté. Comparativement au procédé conventionnel, la solution mise en place est l’une des méthodes la plus économique et écologique à l’échelle mondiale. Dans le but de diminuer encore plus les coûts énergétiques du procédé, l’usage d’une anode dépolarisée à l’hydrogène ((ADH); H2(g) ⇄ 2H+(aq) +2é; E=0,00 V) est considérée. Cette approche demande une certaine compréhension et optimisation de l’électrode à des fins d’adaptation pour l’électrolyse. Ainsi, ce travail tant fondamental qu’appliqué a été réalisé afin d’étudier les phénomènes se produisant à l’ADH. Dans un premier temps, une étude portée sur la cinétique de réaction de l’oxydation de l’hydrogène à l’aide d’une électrode à disque tournant est réalisée. L’influence d’ions lithium et d’une couche catalytique composite sur l’efficacité de la réaction a ainsi pu être démontrée. L’identification des limitations du système a ensuite permis l’optimisation de l’ADH à l’aide d’un plan d’expérience. L’ADH est composée d’un ionomère, d’un catalyseur et d’un support à catalyseur, qui ont des propriétés intrinsèques ayant un impact direct sur l’efficacité et la durabilité de celle-ci. Conséquemment, pour une étude de performance et d’optimisation, plusieurs configurations d’assemblage d’électrode à membrane (MEA) ont été considérées visant à faire varier les proportions des différentes composantes avec un plan d’expérience. Ce projet a ainsi permis l’étude menant à une meilleure compréhension d’une nouvelle technologie d’électrolyse membranaire., In recent years, the development of Li-ion batteries has revolutionized our lifestyles. Given the exponential demand for batteries, the requirement is for base materials, which are synthesized from high-purity lithium salts. Nemaska Lithium, a partner in the project, is recognized as a new producer of lithium hydroxide, using a patented electromembrane process. Compared to the conventional process, this solution is one of the most economical and environmentally friendly methods worldwide. In order to further reduce the energy costs of the process, the use of a hydrogen depolarized anode ((HDA); H2(g) ⇄ 2H+(aq) +2é; E0=0,00 V) is considered. This approach requires some understanding and optimization of the electrode for electrolysis adaptations. Thus, this fundamental and applied work was conducted to study the phenomena occurring at the HDA. First, a study on the kinetics of the hydrogen oxidation reaction using a rotating disk electrode is performed. The influence of lithium ions and a composite catalytic layer on the efficiency of the reaction was demonstrated. The identification of system limitations allowed the optimization of the DHA using a design of experiment. The components of a HDA have intrinsic properties which have a direct impact on its efficiency and durability. They consist of an ionomer, a catalyst, and a catalyst support. Consequently, for a performance and optimization study, several membrane electrode assembly (MEA) configurations were considered in order to vary the proportions of the different components with a design of experiment. This study provided a better understanding and development of this new membrane electrolysis technology.
- Published
- 2021
11. Experimental and computational investigations of platinum complexes of selenium diimide and some novel selenium-nitrogen ligands.
- Author
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Karhu, Aino J., Risto, Maarit, Rautiainen, J. Mikko, Oilunkaniemi, Raija, Chivers, Tristram, and Laitinen, Risto S.
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SELENIUM compounds , *SULFUR diimides , *CHALCOGENS , *MOLECULAR structure of ligands , *PHOSPHINIMINES - Abstract
The reaction of selenium diimide Se[N( t-Bu)]2 and PtCl2 afforded an N,N′-chelated complex [PtCl2{ N,N′-Se[N( t-Bu)]2}] ( 1) in good yield and [PtCl2{ N,N′-SeO[NH( t-Bu)]2}] ( 2) as a minor product. Attempts to prepare 2 by direct reaction of SeOCl2 with Li[NH( t-Bu)] in toluene followed by addition of PtCl2 produced cyclic Se4[N( t-Bu)]4 in solution (77Se NMR spectrum) and a small amount of the complex [PtCl3{ Se, Se′, Se″-Se4[N( t-Bu)]4}][Pt2Cl5{ Se, Se′, Se″-Se3[N( t-Bu)]2}]·3MeCN ( 3·3MeCN), which contains tridentate Se4[N( t-Bu)]4 in the cation and the novel, acyclic bridging ligand [SeN( t-Bu)SeN( t-Bu)Se]2- in the anion. The reaction of Se[N( t-Bu)]2 with [PtCl2(NCPh)2] in THF produced the dinuclear complex [Pt2Cl6{SeN( t-Bu)C(Ph)NH}2]·2C4H8O ( 4·2THF) as the major product and only a few crystals of 1. The possible formation of SeO[NH( t-Bu)]2 or 2 by the reaction of Se[N( t-Bu)]2 or 1, respectively, with adventitious water and the pathway for the production of 4 were investigated through density functional theory calculations. The X-ray structures of 1, 2, 3·3MeCN, and 4·2THF have been determined. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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12. Synthesis, characterization, and anticancer properties of organometallic Schiff base platinum complexes.
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Jean, Stéphanie, Cormier, Kevin, Patterson, Alyssa E., Vogels, Christopher M., Decken, Andreas, Robichaud, Gilles A., Turcotte, Sandra, and Westcott, Stephen A.
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ORGANOMETALLIC compounds , *SCHIFF bases , *PLATINUM compound synthesis , *PLATINUM compounds , *ANTINEOPLASTIC agents , *CHLORIDES , *CANCER treatment , *RENAL cell carcinoma , *THERAPEUTICS - Abstract
A small family of organometallic platinum complexes containing a chloride, cis-cyclooctene, and a Schiff base ligand have been prepared and characterized fully. Three aliphatic amines and four aromatic amines were chosen as representative examples. All complexes were stable in air except for 7, derived from the pinacol-protected 4-aminophenylboronate ester 4-H2NC6H4Bpin (pin = 1,2-O2C2Me4), which decomposed via B-C bond cleavage. Both complexes 4 (derived from aniline) and 7 were further characterized by single-crystal X-ray diffraction studies and confirmed the square planar nature of the platinum centre whereby the chloride ligand lies trans to the deprotonated hydroxyl group of the Schiff base ligand. The imine functionality is trans to the organic cyclooctene group. Complex 3, which contained the longest aliphatic chain studied (an octyl group), was the most promising for inducing apoptosis in the malignant MB231 breast cancer cell line. Conversely, complexes 4- 6, which contained aromatic groups, were the most active against renal cell carcinoma (RCC) cell lines. [ABSTRACT FROM AUTHOR]
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- 2015
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13. Matériaux luminescents hétérocycliques organiques et organométalliques : vers des applications OLEDs
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Fecková, Michaela, Institut des Sciences Chimiques de Rennes (ISCR), 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 Rennes 1, Univerzita Pardubice, Sylvain Achelle, Filip Bureš, STAR, ABES, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and 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)
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[CHIM.MATE] Chemical Sciences/Material chemistry ,Luminescence ,Pyrimidine ,Diode électroluminescente organique (OLED) ,Platine ,Push-Pull chromophore ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Organic light-Emitting diode (OLED) ,Chromophore push-Pull ,Platinum - Abstract
Since 1987, when the first organic light-emitting diode (OLED) was prepared by C. W. Tang and S. V. Slyke (Eastman Kodak company), there has been a great interest in the development of lighting devices based on organic materials. In this dissertation, organic and organometallic luminophores bearing pyrimidine heterocycle as electron-withdrawing moiety are discussed. Three series with different structural features were prepared: (i) 2,4-di(arylvinyl)- and 2,4,6 tri(arylvinyl)pyrimidines with identical or different peripheral electron-donating groups, (ii) 4-arylvinyl- and 4,6-di(arylvinyl)pyrimidines with twisted phenylacridan structure in position 2 of pyrimidine ring and (iii) 2 phenylpyrimidine cyclometalated platinum (II) complexes. Photoluminescence properties of all final derivatives were measured. Structure-photoluminescence relationships within each series were drawn from these results and thoroughly discussed. Interesting luminescence phenomena, such as tuneable emission by protonation, aggregation-induced emission, dual emission, solid-state emission or white light emission, were observed for certain derivatives across the series., Depuis 1987, date à laquelle la première diode électroluminescente organique (OLED) a été préparée par C. W. Tang et S. V. Slyke (Eastman Kodak company), il y a eu un grand intérêt pour le développement de dispositifs d'éclairage à base de matériaux organiques. Dans ce manuscrit, des luminophores organiques et organométalliques portant un hétérocycle pyrimidine en tant que groupement attracteur d'électrons sont discutés. Trois séries avec des caractéristiques structurelles différentes ont été préparées: (i) Une série de 2,4-di (arylvinyl)- et de 2,4,6-tri(arylvinyl)pyrimidines avec des groupes électro-donneurs périphériques identiques ou différents, (ii) Une série de 4-arylvinyl- et de 4,6-di(arylvinyl)pyrimidines portant un groupement phénylacridine torsadé en position 2 du cycle pyrimidine (iii) Des complexes de platine (II) cyclométalé à base de 2-phénylpyrimidine. Les propriétés de photoluminescence de tous les dérivés finaux ont été mesurées. Des relations structure-photoluminescence au sein de chaque série ont été tirées de ces résultats et discutées en détail. Des phénomènes de luminescence intéressants, tels que l'émission accordable par protonation, l'émission induite par l'agrégation, l’émission duale, l'émission à l'état solide ou l'émission de lumière blanche, ont été observés pour certains de ces dérivés.
- Published
- 2021
14. Potentiale der kombinierten H- und E-Feldmessung für die Bestimmung von Spannungs- und Stromverteilungen in Leiterbahnen
- Abstract
Die Sicherstellung der elektromagnetischen Verträglichkeit gehört zu den Anforderungen an Elektronikkomponenten. Hierbei muss auch die feldgebundene Störaussendung von Platinen bestimmt werden. Stellt sich dabei heraus, dass ein nicht tolerierbares Maß an Störungen verursacht wird, so ist häufig die genaue Lokalisierung der Störquellen von Interesse. Hierzu sollten primär die Leiterbahnen als abstrahlende Strukturen untersucht werden. Auf Platinen ist die direkte Messung der Ströme und Spannungen aufgrund der schlechten Zugänglichkeit der Messpunkte und der Problematik der Rückwirkungsfreiheit kaum möglich. Nahfeldmessungen oberhalb einer Platine können helfen, die Ströme zu identifizieren. Mit den Messdaten kann die Stromverteilung auf den in ihrer Lage als bekannt angenommenen Leiterbahnen rekonstruiert werden. Für diese Rekonstruktion können verschiedene Feldmodelle verwendet werden. Ein möglicher Ansatz ist die Momentenmethode [1]. Dem gegenüber steht eine Feldmodellierung mit Hilfe von Hertzschen Dipolen [2], [3]. Bisher wurden hauptsächlich Magnetfelddaten für die Rekonstruktion verwendet. In dem vorliegenden Beitrag werden neben den magnetischen Nahfelddaten auch elektrische Feldmessungen zur Rekonstruktion verwendet. Die Verwendung des elektrischen Feldes zur Rekonstruktion der Stromverteilung wurde auch in [4] und [5] untersucht. Dabei modelliert [4] das elektrische und magnetische Feld auf Basis von Dipolen. [5] untersucht lediglich das elektrische Feld und modelliert dieses anhand von Greenschen Funktionen. Der hier vorgestellte neue Ansatz unterscheidet sich in verschiedenen Punkten von [4] und [5]. Zunächst wird wie in [6] zusätzlich die Information über die Lage der Leiterbahnen verwendet und die Leitungstheorie als Randbedingung für die zu rekonstruierenden Stromverteilungen verwendet. Außerdem wird ein anderer Ansatz zur simultanen Betrachtung der elektrischen und magnetischen Felddaten als in [4] verwendet. Es werden einlagige Platinen mit durchgäng
- Published
- 2020
15. Oxidation of dimethylplatinum(II) complexes with malonyl peroxide derivatives.
- Author
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Hazlehurst, Richard J., Pellarin, Kyle R., McCready, Matthew S., and Puddephatt, Richard J.
- Subjects
- *
ETHANES , *COMPLEX compounds , *PLATINUM compounds , *PEROXIDES , *CHEMICAL derivatives , *CYCLOBUTANE , *LIGANDS (Chemistry) , *OLIGOMERS - Abstract
The reaction of the cyclic peroxides cyclobutane malonoyl peroxide and cyclopentane malonoyl peroxide to dimethylplatinum(II) complexes with the bidentate nitrogen donor ligand 4,4′-di- t-butyl-2,2′-bipyridine (bubpy) gave a mixture of the products of cis and trans oxidative addition, [PtMe2{(O2C)2C(C3H6)}(bubpy)] and [PtMe2{(O2C)2C(C4H8)}(bubpy)], respectively. The cis isomers exist with a chelating dicarboxylate ligand, forming a six-membered ring, while the trans isomers are thought to exist as oligomers, which may react with water or solvent to give complexes containing a monodentate dicarboxylate ligand. Equilibration of the product of cis oxidative addition, cis-[PtMe2{(O2C)2C(C3H6)}(bubpy)], with oxalic or phthalic acid to give equilibria with the oxalate cis-[PtMe2(O4C2)(bubpy)] or phthalate cis-[PtMe2{(O2C)2C6H4}(bubpy)] derivative, respectively, indicated the expected sequence of chelate stability oxalate > cyclobutane malonate > phthalate. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
16. Study of the valuation of bio-sourced molecules by electrocatalytic conversion
- Author
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Kouame, Bitty Roméo Serge, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers, Christophe Coutanceau, Stève Baranton, and Karine de Oliveira Vigier
- Subjects
Electro-Oxidation of glycerol and diglycerol ,Platine ,Électro-Oxydation de glycérol et diglycérol ,[CHIM.CATA]Chemical Sciences/Catalysis ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Palladium ,Amine ,Platinum - Abstract
Glycerol is a by-product of the transesterification reaction of vegetable oils by methanol leading to the formation of methyl ester (methanolysis), with the weight ratio of 10 wt.%. Stocks are increasing significantly worldwide. Glycerol can be converted into high added value compounds of interest for industries of fine chemistry, cosmetic, detergent, food, etc., together with the co-production of electrical energy or hydrogen when its conversion is performed in electrochemical reactors. On the one hand, Pt-based mono and bimetallic catalysts (Pt/C, PtxAg10-x/C, PtxBi10-x/C, PtxCu10-x/C, PtxCo10-x/C, PtxIn10-x/C, PtxNi10-x/C, with x = 1, 2 or 3) catalysts and, on the other hand, palladium-based (Pd/C, Pd9Bi1/C, Pd7Cu3/C, Pd7In3/C and Pd7Ag3/C) catalysts have been synthesized by a wet chemistry method and characterized, with the objective of favor the electrooxidation reaction of glycerol and diglycerol towards aldehydes and ketones. The reactivity of glycerol and diglycerol was evaluated in an alkaline medium to determine the catalyst offering the best conversion. The selectivity of catalysts was studied by in-situ infrared spectroscopy. The best catalysts in terms of activity and selectivity were used at the anode of a 100 cm² electrolysis cell and electrolyses of alkaline solutions of glycerol or diglycerol were carried out at different voltages in order to evaluate the distribution of the reaction products. The reductive amination with ammonia on the one hand and n-butylamine on the other hand on products of interest (glyceraldehyde / dihydroxyacetone) has been successively carried out.; Le glycérol est formé comme produit secondaire à hauteur de 10 wt% lors du processus de trans-estérification d’huiles végétales pour la production d’ester méthyliques et est donc considéré comme un déchet. Ses stocks à travers le monde augmentent significativement. Or, la conversion du glycérol peut permettre d’obtenir des composés à haute valeur ajoutée pour le domaine de la chimie fine, la cosmétique, les détergents l’alimentaire etc., avec la co-production d’énergie électrique ou d’hydrogène lorsqu’elle est réalisée dans des réacteurs électrochimiques. De catalyseurs mono-et bimétallique à base de platine d’une part (Pt/C, PtxAg10-x/C, PtxBi10-x/C, PtxCu10-x/C, PtxCo10-x/C, PtxIn10-x/C, PtxNi10-x/C, avec x=1, 2 et 3) et de palladium d’autre part (Pd/C, Pd9Bi1/C, Pd7Cu3/C, Pd7In3/C et Pd7Ag3/C) ont été synthétisés avec pour objectif d’électro-oxyder le glycérol en aldéhyde et/ou cétone. Ces matériaux ont été caractérisés par des méthodes physico-chimiques et électrochimiques afin d’établir une corrélation structure de surface/réponse électrochimique. Les réactivités du glycérol et du diglycérol ont été évaluées en milieu alcalin pour déterminer le catalyseur offrant la meilleure conversion. La sélectivité des catalyseurs a été étudiée par spectroscopie infrarouge in-situ. Les meilleurs catalyseurs en termes d’activité et de sélectivité ont été utilisés dans une cellule d’électrolyse de 100 cm² pour accumuler les produits de réactions et les analyser. Enfin, l’amination réductrice par l’ammoniac d’une part et la n-butylamine d’autre part sur les produits d’intérêt (glycéraldéhyde/dihydroxyacétone) a été réalisée avec succès.
- Published
- 2020
17. Étude de la valorisation de molécules bio-sourcées par conversion électrocatalytique
- Author
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Kouame, Bitty Roméo Serge, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers, Christophe Coutanceau, Stève Baranton, and Karine de Oliveira Vigier
- Subjects
Electro-Oxidation of glycerol and diglycerol ,Platine ,Électro-Oxydation de glycérol et diglycérol ,[CHIM.CATA]Chemical Sciences/Catalysis ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Palladium ,Amine ,Platinum - Abstract
Glycerol is a by-product of the transesterification reaction of vegetable oils by methanol leading to the formation of methyl ester (methanolysis), with the weight ratio of 10 wt.%. Stocks are increasing significantly worldwide. Glycerol can be converted into high added value compounds of interest for industries of fine chemistry, cosmetic, detergent, food, etc., together with the co-production of electrical energy or hydrogen when its conversion is performed in electrochemical reactors. On the one hand, Pt-based mono and bimetallic catalysts (Pt/C, PtxAg10-x/C, PtxBi10-x/C, PtxCu10-x/C, PtxCo10-x/C, PtxIn10-x/C, PtxNi10-x/C, with x = 1, 2 or 3) catalysts and, on the other hand, palladium-based (Pd/C, Pd9Bi1/C, Pd7Cu3/C, Pd7In3/C and Pd7Ag3/C) catalysts have been synthesized by a wet chemistry method and characterized, with the objective of favor the electrooxidation reaction of glycerol and diglycerol towards aldehydes and ketones. The reactivity of glycerol and diglycerol was evaluated in an alkaline medium to determine the catalyst offering the best conversion. The selectivity of catalysts was studied by in-situ infrared spectroscopy. The best catalysts in terms of activity and selectivity were used at the anode of a 100 cm² electrolysis cell and electrolyses of alkaline solutions of glycerol or diglycerol were carried out at different voltages in order to evaluate the distribution of the reaction products. The reductive amination with ammonia on the one hand and n-butylamine on the other hand on products of interest (glyceraldehyde / dihydroxyacetone) has been successively carried out.; Le glycérol est formé comme produit secondaire à hauteur de 10 wt% lors du processus de trans-estérification d’huiles végétales pour la production d’ester méthyliques et est donc considéré comme un déchet. Ses stocks à travers le monde augmentent significativement. Or, la conversion du glycérol peut permettre d’obtenir des composés à haute valeur ajoutée pour le domaine de la chimie fine, la cosmétique, les détergents l’alimentaire etc., avec la co-production d’énergie électrique ou d’hydrogène lorsqu’elle est réalisée dans des réacteurs électrochimiques. De catalyseurs mono-et bimétallique à base de platine d’une part (Pt/C, PtxAg10-x/C, PtxBi10-x/C, PtxCu10-x/C, PtxCo10-x/C, PtxIn10-x/C, PtxNi10-x/C, avec x=1, 2 et 3) et de palladium d’autre part (Pd/C, Pd9Bi1/C, Pd7Cu3/C, Pd7In3/C et Pd7Ag3/C) ont été synthétisés avec pour objectif d’électro-oxyder le glycérol en aldéhyde et/ou cétone. Ces matériaux ont été caractérisés par des méthodes physico-chimiques et électrochimiques afin d’établir une corrélation structure de surface/réponse électrochimique. Les réactivités du glycérol et du diglycérol ont été évaluées en milieu alcalin pour déterminer le catalyseur offrant la meilleure conversion. La sélectivité des catalyseurs a été étudiée par spectroscopie infrarouge in-situ. Les meilleurs catalyseurs en termes d’activité et de sélectivité ont été utilisés dans une cellule d’électrolyse de 100 cm² pour accumuler les produits de réactions et les analyser. Enfin, l’amination réductrice par l’ammoniac d’une part et la n-butylamine d’autre part sur les produits d’intérêt (glycéraldéhyde/dihydroxyacétone) a été réalisée avec succès.
- Published
- 2020
18. Photoswitchable organoplatinum complexes containing an azobenzene derivative of 3,6-di(2-pyridyl)pyridazine.
- Author
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Moustafa, Mohamed E., Boyle, Paul D., and Puddephatt, Richard J.
- Subjects
- *
AZOBENZENE derivatives , *PLATINUM , *LIGANDS (Chemistry) , *NUCLEAR magnetic resonance , *PHOTOCHEMISTRY - Abstract
The new, unsymmetrical azobenzene-tagged ligand 4-(4-azobenzene)-3,6-di(2-pyridyl)pyridazine, adpp, forms complexes with platinum(II) and platinum(IV), which exist as a mixture of geometrical isomers. The complexes are characterized primarily by their NMR spectra, while the structures of the ligand and its complexes [PtMe2(adpp)], [PtBrMe2(CH2C6H4-4- t-Bu)(adpp)], and [PtBrMe2(CH2C6H3-3,5- t-Bu2)(adpp)] have been structurally characterized. In solution, the compounds undergo easy photochemical trans− cis switching of the azobenzene group, with subsequent slow thermal isomerization back to the more stable trans-azobenzene isomer. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
19. Electrocatalysis and photoelectrochemistry based on functional nanomaterials.
- Author
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Chen, Aicheng
- Subjects
- *
PHOTOELECTROCHEMISTRY , *ELECTROCATALYSIS , *NANOSTRUCTURED materials , *CHEMICAL industry , *FOOD industry , *CATALYTIC activity , *CHEMICAL detectors - Abstract
Catalysis plays a key role in chemical production, energy processing, air purification, water treatment, food processing, and the life sciences. Nanostructured materials with high surface areas and some unique properties have received widespread interest in electrocatalysis and photocatalysis. Recently, the author's research team has designed and studied a variety of novel functional nanomaterials. This review article is derived from the author's 2013 Canadian Catalysis Lectureship Award Lecture and focuses primarily on the electrocatalytic activities of platinum- and palladium-based nanomaterials and the development of TiO2-based nanostructured photocatalysts. Palladium possesses several exceptional properties that may enable promising applications in hydrogen detection, purification, and storage. The significant roles of palladium-based nanomaterials in facilitating the growth of a hydrogen economy are addressed. As platinum-based catalysts are vital to the development of fuel cells and sensors, the design of high-performance platinum-based electrocatalysts is highlighted. Additionally, TiO2 is considered to be one of the most promising photocatalysts due to its nontoxicity, high stability, and cost effectiveness. The modification of TiO2 nanomaterials to achieve visible light response is discussed as well. It is anticipated that the development of advanced functional nanostructured catalysts will further improve the efficiency and reduce the cost of electrochemical and photochemical processes, making them more attractive in addressing the pressing global energy and environmental issues. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
20. Contribution to the study of thermal boundary conditions in hot forming; development of new experimental setups dedicated to emissivity and thermal contact resistance (TCR) measurements at high temperature
- Author
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Abdelmagid El Bakali, Institut Clément Ader (ICA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Ecole des Mines d'Albi-Carmaux, Yannick Le Maoult, Thomas Pottier, Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)
- Subjects
IR Thermography ,Spectrométrie IR ,Formage superplastique ,Emissivity ,Inconel 625 ,TA6V ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Superplastic forming ,Résistance thermique de contact (RTC) ,Platine ,IR Spectrometry ,Emissivité ,Thermographie IR ,Thermal contact resistance (TCR) ,Platinum - Abstract
The present work deals with the high temperature heat transfers involved in sheet/die contact within hot forming processes. The investigated heat ranges lie between 600°C and 1000°C while the study materials are namely TA6V and Inconel 625 (for the sheet) and AISI 310 stainless steel and refractory concrete (for the die). Under such industrial configuration, the heat transfers can be split in two steps: i) a gap closing phase during which the radiative property of the contact pair prevail and ii) a solid contact phase during which the conductive properties are involved and more precisely the thermal contact resistance (TCR). This twostep approach allows a separate investigation of both phenomena which are herein studied by the mean of two dedicated experimental means: a) The gap closing phase is studied through an emissivity measurement setup dedicated to high temperature. The chosen setup is inspired from elliptical oven setups. Its features include a heating rate over 11°C/s and a maximal in-service temperature of 1250°C. The related measurement instruments selection and design are also part of the presented work. The metrological aspects along with the uncertainty quantification are performed through the use of a reference material: pure platinum. This latter has proven worthy by its ability to sustain very high temperature while remaining free from oxidation. In addition, platinum’s optical properties are well documented throughout the scientific literature which provides solid comparisons with other published results. Finally, the construction of an emissivity database is presented for the two sheet materials of the study: TA6V and INCONEL 625. b) The solid contact phase is studied through a second tailor made experimental setup dedicated to TCR measurements. The proposed features include the ability to study metal contact pair (AISI 310 vs. TA6V/INCONEL 625) or ceramic vs. metal contact (Concrete vs. TA6V/INCONEL 625) for temperature as high as 800°C. The whole setup can be inserted within a classical tensile device in order to load the contact interfaces at stress levels similar to those involved in metal forming processes (here up to 4MPa). In practice, a circular sample cut from the studied sheet metals is clasped in between two cylindrical bars made of AISI 310 or concrete. The upper bar is then heated up by the mean of a resistive oven in order to generate a directional heat flux throughout the material interfaces. A suited measurement instrumentation then allows the assessment of the TRC for each contact pair for temperature ranging from 450°C to 800°C and pressure ranging from 0.1MPa to 4MPa. The results obtained from these two setups have built up a material database that was then use to simulate industrial hot forming operations. The process parameters retrieved from these simulation were used as input in an actual forming process and has led to the successful manufacturing of four parts all of which satisfying the quality requirements in term of geometry and microstructure.; Les travaux présentés ici concernent les échanges de chaleur entre une tôle métallique et un moule en béton réfractaire ou en acier inoxydable sont abordés pour des températures comprises entre 600 et 1000°C, voire plus. Ces échanges sont décomposés en deux étapes : une phase d’approche sans contact dite radiative qui nécessite la détermination des propriétés radiatives des solides en présence puis une phase avec contact : détermination d’une Résistance Thermique de Contact (ou « RTC ») à haute température. Pour décrire ces deux étapes, deux nouveaux moyens expérimentaux ont été étudiés et développés :a) Un banc de mesure directe de l’émissivité à chaud a été développé afin d’étudier la phase sans contact. Une enceinte elliptique utilisant le principe d’un four à images a permis d’obtenir des températures élevées (jusqu’à 1250°C) ainsi que des vitesses de chauffe élevées (>11°C/s) sur les échantillons à caractériser. Une instrumentation permettant de réaliser des mesures d’émissivité spectrale et totale a également été développée. La méthodologie de mesure a été validée en choisissant le platine comme matériau de référence, de par sa bonne stabilité chimique, la faible dépendance de ses propriétés avec la température et des propriétés bien documentées. L’émissivité du TA6V et de l’Inconel 625 en fonction de la température ([600 ; 1000]°C) et du temps de chauffage (jusqu’à 5 heures) a ensuite été étudiée. b) Le développement d’un banc de mesure de la RTC à haute température a permis quant à lui d’étudier la phase avec contact. Ce moyen a pour objectif de mesurer la RTC entre des couples de matériaux métal/métal (TA6V ou Inconel 625 /Inox 310) ou métal/céramique (TA6V ou Inconel 625 /Béton réfractaire) pour des pressions allant jusqu’à 4MPa. L’approche adoptée a été de disposer une pastille métallique représentant la tôle (TA6V ou Inconel 625) entre deux barreaux représentant l’outil (Inox 310 ou béton réfractaire), eux-mêmes, amarrés à une machine de traction. Le chauffage a été réalisé en introduisant le barreau supérieur dans un four résistif porté à 1000°C maximum. L’instrumentation du barreau inférieur a permis de déterminer le flux de chaleur conductif traversant ainsi que sa température de surface, ce qui a permis de mesurer la RTC sur une gamme thermique comprise entre 450 et 800°C et une gamme de pression de contact comprise entre 0,1 et 4MPa. Les résultats obtenus à l’aide de ces deux bancs peuvent être intégrés dans des simulations numériques de formage, pour calculer des recettes de lampes. Ces valeurs ont conduit au formage réussi de de 4 tôles successives en TA6V avec de bonnes conformités géométriques et microstructurales.
- Published
- 2020
21. Pt−Me bond cleavage in the reactions of dimethylplatinum(II) complexes containing chelating phosphine ligands with organotin(IV) chlorides.
- Author
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Momeni, Badri Z. and Eatezadi, Sedigheh
- Subjects
- *
PLATINUM compounds , *METAL complexes , *CHELATING agents , *PHOSPHINE , *LIGANDS (Chemistry) , *ORGANOTIN compounds , *CHLORIDES , *CHEMICAL reactions - Abstract
Selective Pt−Me bond activation of dimethylplatinum(II) complexes [PtMe2(PP)] (PP = dppm (bis(diphenylphosphino)methane), dppe (1,2-bis(diphenylphosphino)ethane), dppp (1,3-bis(diphenylphosphino)propane)) was achieved by SnMe2Cl2 to yield the corresponding platinum(II) complexes [PtMeCl(PP)] (PP = dppm, dppe, dppp) and cis-[PtCl2(PP)] (PP = dppm, dppp). On the other hand, the reactions of complexes [PtMe2(PP)] (PP = dppm, dppe, dppp) with SnPh3Cl resulted in the selective cleavage of the Pt−Me bond to afford the methylplatinum(II) complexes [PtMeCl(PP)]. Notably, the reaction of [PtMe2(dppm)] with SnMe2Cl2 and SnPh3Cl also gave the ionic A-frame complex [Pt2Me2(μ-Cl)(μ-dppm)2]Cl. The variable-temperature 1H and 31P NMR spectroscopy shows that the cleavage of the Pt−Me bond occurs very rapidly and the short-lived platinum(IV) intermediate is difficult to detect during the reaction. An explanation is presented on the basis of the nature of the strong π-acceptance of the phosphine ligand, which resulted in the formation of a very unstable platinum(IV) intermediate. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
22. Chimiothérapie des cancers épithéliaux de l'ovaire.
- Author
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Tazi, Y., Pautier, P., Leary, A., and Lhomme, C.
- Subjects
- *
CANCER chemotherapy , *OVARIAN cancer , *CARBOPLATIN , *CARCINOMA , *PACLITAXEL , *CANCER relapse , *THERAPEUTICS - Abstract
Résumé: La chimiothérapie est fondamentale dans la prise en charge des carcinomes épithéliaux de l’ovaire aussi bien pour les stades précoces (traitement uniquement chirurgical dans de rares cas) qu’avancés et dans pratiquement toutes les étapes évolutives de la maladie. Le schéma de référence associe carboplatine-paclitaxel par voie intraveineuse. La voie intrapéritonéale a également prouvé son efficacité en première ligne dans les stades avancés après une chirurgie complète mais doit être réservée à des équipes entraînées en raison de ses contraintes techniques et des toxicités dont elle peut être responsable. En cas de rechute ou de progression les modalités de la chimiothérapie dépendent principalement de l’intervalle libre entre ce diagnostic et la dernière injection de platine. Le bévacizumab a prouvé son efficacité en prolongeant la survie sans progression en 1er ligne de traitement en association avec la chimiothérapie puis en maintenance ainsi que dans les rechutes ou progressions aussi bien sensibles que résistantes aux platines. Enfin, une meilleure connaissance de la biologie des cancers de l’ovaire permet d’envisager dans l’avenir des thérapeutiques personnalisées guidées par les caractéristiques spécifiques de chaque patiente et de chaque tumeur. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
23. Process for recycling fuel cell membrane electrode assemblies (MEAs) using ionic liquids
- Author
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Coudray, Mathias, Laboratoire de Chimie, Catalyse, Polymères et Procédés, R 5265 (C2P2), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon, Véronique Dufaud, Emmanuel Billy, Hakima Mendil, Paul Henri Haumesser, Catherine Santini, and STAR, ABES
- Subjects
Pile à combustible à membrane échangeuse de protons ,Nafion ,Nanoparticules ,Recovering ,Stabilization ,Ionic liquids ,Liquides ioniques ,[CHIM.OTHE] Chemical Sciences/Other ,Platine ,Proton-exchange membrane fuel cell ,Nanoparticles ,Recycling ,Recyclage ,Stabilisation ,Récupération ,[CHIM.OTHE]Chemical Sciences/Other ,Platinum - Abstract
Recovery of the protons-exchange membrane fuel cell (PEMFC) membrane electrode assemblies (MEAs) is an important issue for the growing of the fuel cells market. These MEAs contain platinum (Pt), which as a precious metal mainly influences the total cost of fuel cells. The recycling of Pt is still based to a great extent on hydro or pyrometallurgical techniques which produce toxic and pollutant gas emissions. Some studies aimed to set up processes to recycle platinum in a more sustainable way than traditional metal lixiviation using strong acids. The study here is part of this research field and is about a new way to separate the different components of the PEMFC electrode using ionic liquids for the recycling of these valuable materials. These liquids possess excellent thermal and chemical stability and their non-volatility can be useful to set up a safer way to recover platinum. A selection of ionic liquids was studied and some of them, including the P66614Cl (trihexyltetradecylphosphonium chloride), could be use to recover Pt nanoparticles detached from their carbon support and stabilized in the ionic liquid. A study on the interactions of ionic liquids and the components of the MEA allowed the extraction mecanisms to be better understood. Thus the ionics liquids interact strongly with Nafion in the catalyst layer which allows Pt nanoparticles to be recovered. These strong interactions set the stage for the simultaneous recycling of Nafion and Pt from MEAs, Le recyclage des assemblages membrane électrode (AMEs) des piles à combustible à membrane échangeuse de protons (PEMFC) est en enjeu important pour le développement du marché de ces piles fonctionnant à l’hydrogène. Dans ces AMEs se trouvent le platine (Pt), un métal précieux et rare qui conditionne majoritairement le coût total de la pile. Le recyclage du Pt est encore largement effectué par hydro ou pyrométallurgie ce qui entraîne le rejet de gaz toxiques et polluants dans l’environnement. Plusieurs études ont porté sur la mise en place d’une voie plus soutenable écologiquement que le traditionnel usage d’acides forts pour lixivier le platine. Le procédé proposé ici s’inscrit dans ce domaine de recherche en proposant une nouvelle voie de séparation des constituants de l’électrode de PEMFC en vu de leur recyclage par l’utilisation de liquides ioniques. Ceux-ci par leur stabilité thermique et chimique et leur non-volatilité peuvent permettre la mise en place d’un procédé de récupération du platine sûr. Après l’étude d’une sélection de liquides ioniques plusieurs d’entre eux, dont le P66614Cl (trihexyltetradécylphosphonium chlorure), ont permis la récupération du platine sous forme de nanoparticules détachées et stabilisées dans le liquide ionique. Une étude des interactions du liquide ionique avec chacun des composants de l’AME a permis de mieux comprendre les mécanismes d’extraction. Le liquide ionique interagit ainsi fortement avec l’ionomère présent dans la couche catalytique. Cette forte interaction ouvre la voie à un retraitement simultané du Nafion et du platine des AMEs
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- 2019
24. Synthèse de nanocatalyseurs métalliques supportés pour l'électrooxydation du glucose : application en pile implantable
- Author
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Lemoine, Charly, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers, Kouakou Boniface Kokoh, Karine Servat, and Têko Wilhelmin Napporn
- Subjects
Électrochimie ,Or ,Électrocatalyse ,Synthesis ,[CHIM.ANAL]Chemical Sciences/Analytical chemistry ,Platine ,Oxidation ,Electrochemistry ,Pile à combustible ,Bae ,Oxydation ,Platinum ,Synthèse ,[CHIM.CATA]Chemical Sciences/Catalysis ,Implantable Fuel Cell ,Nanocatalyseurs ,Glucose ,Fuel Cell ,Graphène ,Polyol ,Pile implantable ,Gold ,Support ,Graphene ,Electrocatalysis ,Nanocatalysts - Abstract
Supplying durable power to implanted electronic devices is a major challenge in medicine and bio-monitoring fields. Due to glucose renewability and presence in biological organisms, Glucose/Oxygen fuel cell is a power source adapted to these applications. In this work, catalysts made of gold and platinum nanoparticles, dispersed on carbon supports such as Vulcan, graphene oxide (GO) and reduced graphene oxide (rGO), were synthesized by two methods (Bromide Anion Exchange - BAE and polyol). These mono- (Pt, Au) and bi-metallic (AuxPty) catalysts were used as fuel cell anode to be implanted in an animal for powering a health monitoring device. Physico-chemical characterizations (Raman, MET, DRX, XPS) of materials permitted to determine their structure, their surface composition, and the metal-support interactions. Then, electrochemical techniques (voltammetry, CO-stripping and chronoamperometry) permitted to reveal their activity towards glucose oxidation and oxygen reduction reactions and their stability in alkaline and phosphate media. During glucose/O2 fuel cell testings with anion exchange membrane, Pt/rGO was the most efficient catalyst, and Pt-rich bimetallic materials were the most stable. In PBS buffer, fuel cell performances depicted by open circuit voltage (OCV) and power density (Pj) reached 0.7 V and 28 microW.cm-2 respectively. Without membrane, the mixing of reactants, near-implantation conditions, caused an inhibition effect on OCV (0.4 V) and power density (8 µW.cm-2).Chromatographic analysis and mass spectrometry permitted to identify gluconate and glucuronate as sole glucose oxidation products, which are non-toxic and value-added chemicals.; L’alimentation durable des dispositifs électroniques implantés est un défi majeur dans les domaines de la médecine et du bio-monitoring. La pile Glucose/Oxygène est une source d’énergie adaptée à ces applications car le glucose est un combustible renouvelable et présent dans les systèmes biologiques. Dans cette étude, des catalyseurs constitués de nanoparticules d’or et de platine dispersés sur des substrats de carbone tels que le Vulcan, l’oxyde de graphène (GO) et l’oxyde de graphène réduit (rGO) ont été préparés par deux voies de synthèse (Bromide Anion Exchange - BAE et polyol). Ces catalyseurs mono- (Pt, Au) et bi-métalliques (AuxPty) ont été utilisés en tant qu’anode de pile implantée dans un animal pour alimenter un dispositif de suivi médical. Les caractérisations physico-chimiques (Raman, MET, DRX, XPS) des matériaux ont permis la détermination de leur structure, leur composition de surface et les interactions métal-support. Ensuite, les techniques électrochimiques (voltammétrie, CO-stripping et chronoampérométrie) ont permis de révéler leur activité et stabilité lors de l’oxydation du glucose et la réduction de l’oxygène en milieux alcalin et phosphate. Lors des tests en pile glucose/O2 avec membrane échangeuse d’ions, Pt/rGO s’est imposé comme le catalyseur le plus performant, et les matériaux bimétalliques à haute teneur en platine comme les plus stables. En tampon PBS, les performances de la pile caractérisées par la tension de pile à circuit ouvert (OCV) et la densité de puissance (Pj) atteignèrent respectivement 0,7 V et 28 microW.cm-2. En l’absence de membrane, le mélange des réactifs, conditions proches de l’implantation, montrait un effet inhibiteur sur l’OCV (0,4 V) et la densité de puissance (8 µW.cm-2).Des analyses par chromatographie et spectrométrie de masse ont permis d’identifier le gluconate et le glucuronate comme seuls produits d’oxydation du glucose, qui sont non-toxiques et à haute valeur ajoutée.
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- 2019
25. Synthesis of Supported Metallic Nanocatalysts for Glucose Electrooxidation : Application in Implantable Fuel Cell
- Author
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Lemoine, Charly, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers, Kouakou Boniface Kokoh, Karine Servat, and Têko Wilhelmin Napporn
- Subjects
Électrochimie ,Or ,Électrocatalyse ,Synthesis ,[CHIM.ANAL]Chemical Sciences/Analytical chemistry ,Platine ,Oxidation ,Electrochemistry ,Pile à combustible ,Bae ,Oxydation ,Platinum ,Synthèse ,[CHIM.CATA]Chemical Sciences/Catalysis ,Implantable Fuel Cell ,Nanocatalyseurs ,Glucose ,Fuel Cell ,Graphène ,Polyol ,Pile implantable ,Gold ,Support ,Graphene ,Electrocatalysis ,Nanocatalysts - Abstract
Supplying durable power to implanted electronic devices is a major challenge in medicine and bio-monitoring fields. Due to glucose renewability and presence in biological organisms, Glucose/Oxygen fuel cell is a power source adapted to these applications. In this work, catalysts made of gold and platinum nanoparticles, dispersed on carbon supports such as Vulcan, graphene oxide (GO) and reduced graphene oxide (rGO), were synthesized by two methods (Bromide Anion Exchange - BAE and polyol). These mono- (Pt, Au) and bi-metallic (AuxPty) catalysts were used as fuel cell anode to be implanted in an animal for powering a health monitoring device. Physico-chemical characterizations (Raman, MET, DRX, XPS) of materials permitted to determine their structure, their surface composition, and the metal-support interactions. Then, electrochemical techniques (voltammetry, CO-stripping and chronoamperometry) permitted to reveal their activity towards glucose oxidation and oxygen reduction reactions and their stability in alkaline and phosphate media. During glucose/O2 fuel cell testings with anion exchange membrane, Pt/rGO was the most efficient catalyst, and Pt-rich bimetallic materials were the most stable. In PBS buffer, fuel cell performances depicted by open circuit voltage (OCV) and power density (Pj) reached 0.7 V and 28 microW.cm-2 respectively. Without membrane, the mixing of reactants, near-implantation conditions, caused an inhibition effect on OCV (0.4 V) and power density (8 µW.cm-2).Chromatographic analysis and mass spectrometry permitted to identify gluconate and glucuronate as sole glucose oxidation products, which are non-toxic and value-added chemicals.; L’alimentation durable des dispositifs électroniques implantés est un défi majeur dans les domaines de la médecine et du bio-monitoring. La pile Glucose/Oxygène est une source d’énergie adaptée à ces applications car le glucose est un combustible renouvelable et présent dans les systèmes biologiques. Dans cette étude, des catalyseurs constitués de nanoparticules d’or et de platine dispersés sur des substrats de carbone tels que le Vulcan, l’oxyde de graphène (GO) et l’oxyde de graphène réduit (rGO) ont été préparés par deux voies de synthèse (Bromide Anion Exchange - BAE et polyol). Ces catalyseurs mono- (Pt, Au) et bi-métalliques (AuxPty) ont été utilisés en tant qu’anode de pile implantée dans un animal pour alimenter un dispositif de suivi médical. Les caractérisations physico-chimiques (Raman, MET, DRX, XPS) des matériaux ont permis la détermination de leur structure, leur composition de surface et les interactions métal-support. Ensuite, les techniques électrochimiques (voltammétrie, CO-stripping et chronoampérométrie) ont permis de révéler leur activité et stabilité lors de l’oxydation du glucose et la réduction de l’oxygène en milieux alcalin et phosphate. Lors des tests en pile glucose/O2 avec membrane échangeuse d’ions, Pt/rGO s’est imposé comme le catalyseur le plus performant, et les matériaux bimétalliques à haute teneur en platine comme les plus stables. En tampon PBS, les performances de la pile caractérisées par la tension de pile à circuit ouvert (OCV) et la densité de puissance (Pj) atteignèrent respectivement 0,7 V et 28 microW.cm-2. En l’absence de membrane, le mélange des réactifs, conditions proches de l’implantation, montrait un effet inhibiteur sur l’OCV (0,4 V) et la densité de puissance (8 µW.cm-2).Des analyses par chromatographie et spectrométrie de masse ont permis d’identifier le gluconate et le glucuronate comme seuls produits d’oxydation du glucose, qui sont non-toxiques et à haute valeur ajoutée.
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- 2019
26. Column base plates under 3D loading
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da Silva Seco, Laura, Laboratoire de Génie Civil et Génie Mécanique (LGCGM), 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), INSA de Rennes, Mohammed Hjiaj, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
- Subjects
M-N interaction ,Flexion biaxiale ,Anchoring ,Interaction M-N ,Biaxial bending ,Platine ,Pied de poteau ,[SPI.GCIV.STRUCT]Engineering Sciences [physics]/Civil Engineering/Structures ,Column base plate ,Ancrage - Abstract
Column bases have a major influence on the stability and stiffness of steel structures. This thesis focuses on the estimation of the resistance of column base plates subjected to a combination of axial force and biaxial bending moment. The investigated connections consist of a steel column welded to a base plate and fixed to the concrete block by means of four anchor bolts. In Chapter II, an extensive literature review is presented, summarizing the existing models for the estimation of the resistance of column base plates as well as the results of previous experimental test campaigns. Chapter III is dedicated to the analysis of the results of a test campaign carried out on 9 column base plates, subjected to in-plane, out-of-plane and bi-axial bending moments. Particular attention is given to the influence of the base plate thickness and orientation of the applied bending moment. Results are presented and discussed, to better understand the elastic and post-limit behaviors. These experimental results are completed with refined numerical simulations presented in Chapter IV. A parametric study is conducted to broaden this investigation, by adding a normal force and other geometrical configurations (column steel profile HEA, IPE, diameter of the anchor bolts). Next, an analytical model is proposed, based on the Component Method in Eurocode 3 Part 1-8, to calculate the resistance of column base plates under uniaxial and biaxial bending moments. The conservative nature of the model is demonstrated by comparing the model predictions against experimental and numerical results.; Les pieds de poteaux ont une influence prépondérante sur la stabilité et la rigidité des charpentes métalliques. Cette thèse porte sur la résistance des pieds de poteaux par platine soumis à un effort normal et un moment bi-axial. Les pieds de poteaux étudiés sont composés d’une platine soudée à l’extrémité du poteau et reliée au bloc béton par 4 tiges. Dans le chapitre II, une étude bibliographique dresse un bilan des modèles permettant de calculer la résistance de ce type d’assemblage ainsi que des résultats d’essais. Le chapitre III est ensuite dédié à la description et l’analyse des résultats d’une campagne d’essais menée sur 9 assemblages soumis à un moment dans le plan, hors plan ou de la flexion bi-axiale. Une attention particulière est accordée à l'influence de l'épaisseur de la platine et de l'orientation du moment. Les résultats sont présentés et discutés afin de mieux comprendre le comportement élastique et plastique. Cette étude est complétée par des analyses par éléments finis dans le chapitre IV validées par confrontation aux résultats d’essais. Une étude paramétrique a ensuite permis d’étendre le domaine d’investigation en ajoutant un effort normal et d’autres configurations géométriques (sections en HEA, IPE, diamètres des tiges d’ancrage). Un modèle analytique, basé sur la méthode des composants de l'Eurocode 3 partie 1-8, est ensuite proposé afin de calculer la résistance des pieds de poteau en flexion uniaxiale (dans le plan et hors plan) et biaxiale. Le caractère conservatif de la méthode est démontré par comparaison aux résultats des essais et des études numériques.
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- 2019
27. Exploration à l’échelle atomique de catalyseurs constitués de platine supporté sur alumine gamma chlorée
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Fialho Batista, Ana Teresa, IFP Energies nouvelles (IFPEN), Université de Lyon, and Pascal Raybaud
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Alumine ,Alumina ,[CHIM.CATA]Chemical Sciences/Catalysis ,STEM ,Reformage ,DFT ,RMN ,XANES ,Tomographie ,EXAFS ,Platine ,Reforming ,Chlorine ,Chlore ,Tomography ,Platinum - Abstract
Bifunctional heterogeneous catalysts consisting of metallic sites and acidic sites are used in various processes and the impact of active site proximity in catalytic efficiency can be expressed as an “intimacy criterion” according to the literature. Platinum supported on chlorinated γ-Al2O3 is the traditional catalyst for catalytic naphtha reforming and is at the core of the present work. Herein, a multi-technique approach, including HR-HAADF-STEM, electron tomography, high field MAS NMR, HERFD-XANES, EXAFS, and DFT calculations, was applied to determine the location of the metallic and acidic sites on the Al2O3 support crystallites for Pt/ γ-Al2O3 -Cl catalysts and to estimate the distance between such sites. The samples, representative of the industrial catalysts, were synthesized so as to vary the distance between the two types of sites as a function of three key parameters: %Pt, %Cl and γ-Al2O3 crystallite size and shape.By building the first DFT model of crystallite edge between the (110) and (100) surfaces, an improved 1H NMR peak assignment was proposed and it was found that µ1-OH on the edge are preferably exchanged with Cl. STEM analysis showed that reduced Pt nanoparticles are of 0.9 nm and that around 20% of Pt is in the form of single atoms, which are stabilized by Cl. By electron tomography it was revealed that Pt nanoparticles are mostly located on the edges of alumina crystallites and that the quantified inter-Pt particles distance is directly tuned through %Pt. A first geometrical model of the location of Pt and Cl on the catalyst is proposed. The improved understanding of the location of active sites and their proximity in catalytic reforming catalysts gained though this work paves the way to catalyst improvement based on tuning of active site location.; Plusieurs procédés industriels utilisent des catalyseurs hétérogènes bifonctionnels avec des sites actif métalliques et acides. L’influence de la distance entre les deux types de site actif sur l’activité et la sélectivité du catalyseur a souvent été décrite par un « critère d’intimité » dans la littérature. Les travaux reportés dans la présente thèse revisitent ce critère en étudiant des catalyseurs constitués de nanoparticules de platine supportées sur alumine gamma chlorée, utilisés en reformage catalytique des coupes pétrolières de type naphtas. Plusieurs techniques, dont la microscopie HR-HAADF-STEM, la tomographie électronique, les spectroscopies RMN MAS à hauts champs, HERFD-XANES, EXAFS et la simulation quantique (DFT), ont été utilisées pour déterminer la localisation des sites métalliques et acides sur les cristallites du support de façon à estimer la distance inter-sites. Les échantillons ont été préparés en faisant varier trois paramètres : teneur en Pt, teneur en Cl et taille et forme des cristallites. Grâce au premier modèle DFT d’arête entre les surfaces (110) et (100) de l’alumine, une attribution plus détaillée des signaux 1H NMR a été proposée montrant que les hydroxyles µ1-OH des arêtes sont plus favorablement échangés avec le Cl. L’étude STEM a révélé des nanoparticules de Pt de 0.9 nm et des atomes isolés qui représentent environ 20% du Pt et qui sont stabilisés par le Cl. Par tomographie électronique, il a été montré que les nanoparticules de Pt sont localisées sur les arêtes des cristallites et que la distance entre elles varie en fonction du %Pt. Enfin, un modèle géométrique du système catalytique Pt/γ-Al2O3-Cl est proposé. Grâce à cette compréhension avancée de la localisation des sites actifs, ce travail ouvre la voie à des améliorations futures des performances de cette famille de catalyseurs grâce au contrôle à l’échelle atomique de l'emplacement des sites actifs.
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- 2019
28. Synthesis of complex heterocycles via Gold(I) catalyzed ammoniumation
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Pertschi, Romain, Institut de Chimie de Strasbourg, Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université de Strasbourg, Patrick Pale, Aurélien Blanc, and STAR, ABES
- Subjects
Cycloisomérisations énantiosélectives ,Tetrahydroazepines ,Enantioselective cycloisomerizations ,[CHIM.ORGA]Chemical Sciences/Organic chemistry ,Benzosultams ,[CHIM.CATA] Chemical Sciences/Catalysis ,Hétérocycles ,Réactions en cascade ,Or ,Heterocycles ,[CHIM.CATA]Chemical Sciences/Catalysis ,[CHIM.ORGA] Chemical Sciences/Organic chemistry ,Homogeneous catalysis ,Tétrahydroazépines ,Benzosultames ,Catalyse homogène ,Azetidine ,Platine ,Cascade reactions ,Pyrroles ,Azétidines ,Gold ,Platinum - Abstract
Nitrogen-containing heterocycles have always retained the attention of chemists considering their potent biological properties as well as their large occurrence in natural product structures. Therefore, the development of new innovative synthetic methods that allow a rapid and efficient access to these heterocycles is highly sought. It is in this philosophy that these PhD works take place, whose aims at the development of new approaches based on gold(I) catalyzed ammoniumation reactions in order to trigger cascade reactions and to reach important nitrogen-containing heterocycles. The N-sulfonyl-2-(1-propargyl) azetidine scaffold allows formation of a large variety of pyrroles and tetrahydroazepines derivatives. The extension of the concept of ammoniumation by using N-(2-alcynylaryl)sulfonyl azetidines allowed the formation of benzosultam derivatives. Another major challenge of modern synthetic chemistry is the formation of enantiopur molecules. To reach this goal, new chiral NHC platinum (II) complexes have been synthesized and evaluated as catalysts for cycloisomerization reactions., Les hétérocycles azotés ont toujours retenu l’attention des chimistes du fait de leurs potentielles activités biologiques mais également pour leurs grandes occurrences dans les produits naturels. De ce fait émerge la nécessité de développer de nouvelles méthodes de synthèse innovantes permettant un accès rapide et efficace à ces hétérocycles. C’est dans cette philosophie que s’inscrivent ces travaux de thèse dont l’objectif est le développement de nouvelles approches basées sur l’utilisation de réactions d’ammoniumation catalysées à l’or(I) afin d’induire des cascades réactionnelles donnant accès à une large variété d’hétérocycles azotés. Ainsi, un motif de base N-sulfonyl-2-(1-propargyl)azétidine a permis d’accéder à une large variété de dérivés pyrroliques et de tétrahydroazépines. L’extension du concept d’ammoniumation lors de l’utilisation des N-(2-alcynylaryl)sulfonyl azétidines a conduit à l’obtention de benzosultames. Un autre défi majeur de la chimie de synthèse moderne est l’obtention de molécules énantiopures. Pour répondre à cette problématique, de nouveaux complexes chiraux NHC platine(II) ont été synthétisés et évalués en tant que catalyseurs sur des réactions de cycloisomérisation.
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- 2019
29. Néphrotoxicité des médicaments.
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Zimner-Rapuch, Sarah, Amet, Sabine, Janus, Nicolas, Deray, Gilbert, and Launay-Vacher, Vincent
- Abstract
Résumé: Les effets rénaux des médicaments se manifestent par divers mécanismes et peuvent potentiellement toucher toutes les parties du rein. Il existe six types d’atteintes rénales induites par les médicaments: les atteintes prérénales ; les néphropathies tubulaires ; les néphropathies interstitielles ; les néphropathies glomérulaires ; les néphropathies vasculaires et les néphropathies obstructives, telles que les cristalluries, les insuffisances rénales aiguës secondaires à des rhabdomyolyses, etc. La néphrotoxicité des médicaments survient principalement chez des patients ayant des facteurs de risque sous-jacents, pouvant rendre le rein plus fragile aux effets iatrogènes. On distingue les facteurs de risque liés au patient (âges extrêmes, hypovolémie, insuffisance rénale chronique préexistante…), ceux liés au rein et ceux liés au traitement (posologie non adaptée, néphrotoxicité cumulée, diurétiques, anti-inflammatoires non stéroïdiens…). La connaissance des facteurs de risque et des mécanismes de néphrotoxicité sont la base d’une meilleure prévention et également d’une meilleure prise en charge de ces patients. [Copyright &y& Elsevier]
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- 2013
- Full Text
- View/download PDF
30. Chelating properties of permethylated 6A,6D-dideoxy-6A,6D-bis(1-imidazolyl)cyclodextrins towards Pt(II) and Ru(III).
- Author
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Egloff, Coraline, Gramage-Doria, Rafael, Jouffroy, Matthieu, Armspach, Dominique, Matt, Dominique, and Toupet, Loïc
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- *
CYCLODEXTRINS , *CHELATION , *RUTHENIUM , *PLATINUM , *IMIDAZOLES , *COORDINATE covalent bond - Abstract
Abstract: Two imidazole-coordinating groups have been successfully grafted onto the C-6A and C-6D positions of permethylated α- and β-cyclodextrin scaffolds. Both water-soluble ligands L1 and L2 turned out to behave as good chelators when reacted with K2PtCl4. In the resulting diamagnetic cis-chelate complexes, the metal cation is pending above the cavity entrance. Paramagnetic ruthenium(III) chelate complexes have also been successfully synthesised from L1 and L2. In these more sterically demanding octahedral complexes, the imidazole groups coordinate the metal centre in a trans-fashion. [Copyright &y& Elsevier]
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- 2013
- Full Text
- View/download PDF
31. Synthesis, characterization, and bioactivities of platinum(II) complexes bearing pyridinecarboxaldimines containing aliphatic groups.
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Stewart, Erin L., Patterson, Alyssa E., O'Neill, Taryn, Li, Haoxin, Flewelling, Andrew, Vogels, Christopher M., Decken, Andreas, Lloyd, Vett K., Gray, Christopher A., and Westcott, Stephen A.
- Subjects
- *
BIOACTIVE compounds , *PLATINUM compounds , *COMPLEX compounds , *PYRIDINE , *ALDIMINES , *ALIPHATIC compounds , *ALIPHATIC amines - Abstract
Condensation of 2-pyridinecarboxaldehyde with six primary amines containing aliphatic groups gave the corresponding pyridinecarboxaldimines (N-N′R). Addition of these ligands to [PtCl2(coe)]2 (coe = cis-cyclooctene) gave complexes of the type cis-PtCl2(N-N′R) ( 1: R = propyl, 2: R = hexyl, 3: R = octyl, 4: R = nonyl, 5: R = hexadecyl, and 6: R = octadecyl) in moderate yields. The molecular structure of the hexyl derivative ( 2) has been confirmed by an X-ray diffraction study. Crystals of 2 were triclinic with a = 8.6858(19) Å, b = 8.7567(19) Å, c = 9.5080(19) Å, α = 76.546(3)°, β = 87.151(3)°, and γ = 78.586(3)° in the space group P1. All platinum complexes show considerable anti-bacterial and anti-mycobacterial properties. [ABSTRACT FROM AUTHOR]
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- 2013
- Full Text
- View/download PDF
32. Oxidative transformation of N-substituted 2-aminophenols to 2-substituted benzoxazoles catalyzed by polymer-incarcerated and carbon-stabilized platinum nanoclusters.
- Author
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Yoo, Woo-Jin, Yuan, Hao, Miyamura, Hiroyuki, and Kobayashi, Shū
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NANOPARTICLES , *AMINOPHENOLS , *BENZOXAZOLES , *NANOSTRUCTURED materials , *PLATINUM , *OXIDATION , *POLYMERS , *CATALYSIS research - Abstract
The preparation of 2-substituted benzoxazoles was achieved through a sequential aerobic oxidation - enolization - oxidative cyclization reaction of N-substituted 2-aminophenols catalyzed by platinum nanoclusters supported on a polymer / carbon black composite material. [ABSTRACT FROM AUTHOR]
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- 2012
- Full Text
- View/download PDF
33. Ferromagnetic coupling induced by spin-orbit coupling in dipyridylamide linear trinuclear Cu-Pd-Cu and Cu-Pt-Cu complexes
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Maynau, Daniel, Bolvin, Hélène, Van den Heuvel, Willem, Bénard, Marc, Rohmer, Marie-Madeleine, and Ben Amor, Nadia
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METAL complexes , *FERROMAGNETISM , *MAGNETIC coupling , *SPIN-orbit interactions , *AMIDES , *WAVE functions ,MAGNETIC properties of complex compounds - Abstract
Abstract: The mechanism of the magnetic coupling in the [CuMCu(pda)4Cl2] complexes with M=Pd, Pt is analyzed. First principles calculations based on the wave function theory are performed (DDCI+SO-RASSI): it is shown that the interaction without spin-orbit coupling is antiferromagnetic while the contribution due to the spin-orbit is ferromagnetic. The agreement between calculations and experiment is very good for the CuPdCu complex but is lesser for the CuPtCu complex. A Hubbard model is used in order to rationalize these results: this shows that the two d frontier orbitals of the central atom play a key role in these two interactions. Although the model parameters extracted from CASCI calculations do not permit to recover the order of magnitude of the interactions, it allows understanding the main interactions that give physical insight. [Copyright &y& Elsevier]
- Published
- 2012
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34. The role of solvent in organometallic chemistry - Oxidative addition with dichloromethane or chloroform.
- Author
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Abo-Amer, Anwar, McCready, Matthew S., Zhang, Fenbao, and Puddephatt, Richard J.
- Subjects
- *
IMINES , *SOLVENTS , *PLATINUM compounds , *ORGANOMETALLIC chemistry , *OXIDATIVE addition , *DICHLOROMETHANE , *METAL complexes , *CHEMICAL reactions , *CHEMICAL structure - Abstract
Dimethylplatinum(II) complexes [PtMe2(NN)], with NN = diimine ligand, can react with dichloromethane or chloroform solvent to give the corresponding organoplatinum(IV) complexes [PtClMe2(CH2Cl)(NN)] or [PtClMe2(CHCl2)(NN)], respectively. The products can exist in isomeric forms, corresponding to products of cis or trans oxidative addition. The structures of three dichloromethane adducts and one chloroform adduct are reported. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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35. Nature du dépôt formé au cours de l’oxydation en voie humide catalysée du phénol
- Author
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Keav, Sylvain, Martin, Agnès, Barbier Jr, Jacques, and Duprez, Daniel
- Subjects
- *
OXIDATION , *RUTHENIUM , *PLATINUM , *CATALYSTS , *ORGANIC compounds , *PHENOL - Abstract
Abstract: The formation of a carbonaceous deposit was shown to occur during catalytic wet air oxidation of phenol over ceria and doped-ceria supported platinum and ruthenium monometallic catalysts. This deposit came in the form of a layer of organic species adsorbed on the catalytic surface. Polycyclic aromatic compounds of the chromenone, xanthenone and fluorenone families could be extracted and identified via chromatographic techniques coupled with mass spectroscopy. These species result from the condensation of phenol with products of its partial oxidation. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
36. Aspects radiobiologiques des traitements anticancéreux par rayonnement synchrotron : bilan et perspectives
- Author
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Foray, N.
- Subjects
- *
CANCER radiotherapy , *CANCER chemotherapy , *SYNCHROTRON radiation , *RADIOBIOLOGY , *TREATMENT effectiveness , *DNA repair - Abstract
Abstract: Each technological development of radiotherapy is an example of interaction between physicians and physicists. In the past, it was the case for the first X-rays generators, betatrons and particle accelerators. To date, this is the case for Cyberknives and intensity modulation radiotherapy. In the future, this will be the case for proton- and hadron-therapy. However, in a general tendency of favouring higher radiation energies, leaving the 250kV orthovoltage irradiators and preferring accelerators delivering some tens MeV to reach the deepest tumours, how to consider the anti-cancer applications of synchrotron radiation that provides X-rays in the 10–100keV “only”? Since the first approaches developed in the USA in seventies until the last preclinical trials performed at the European Synchrotron Radiation Facility of Grenoble, the radiobiological features of the chemoradiotherapy involving synchrotron radiation will be described and analysed throughout a transversal view considering physicochemical bases, biomolecular and cellular mechanisms and results from the preclinical trials in order to provide a general outcome and some eventual transfer perspectives. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
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37. Catalytic removal of propene and toluene in air over noble metal catalyst.
- Author
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Benard, S., Ousmane, M., Retailleau, L., Boreave, A., Vernoux, P., and Giroir-Fendler, A.
- Subjects
- *
PROPENE , *TOLUENE , *METAL catalysts , *OXIDATION , *VOLATILE organic compounds , *CHEMICAL inhibitors - Abstract
In this paper we present the study of catalytic oxidation of volatile organic compound (VOC) traces in air over Pt/γ-Al2O3 catalysts. The study was carried out using a laboratory fixed-bed catalytic reactor (FBCR) with catalytic oxidation of propene and toluene as model reactions. For better understanding of catalytic activity in a FBCR, the influence of operating parameters such as of platinum (Pt) loading, total gas flow rate, VOC concentration, and oxygen content were studied. The results showed that catalytic activity increases with increase in VOC concentration and a decrease in total gas flow rate. This displayed behaviour is instrumental to working at a low temperature region for complete oxidation of volatile organic compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
38. Organoplatinum(IV) complexes with functional alkyl groups and their use in supramolecular chemistry1.
- Author
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Au, Richard H. W., Findlay-Shirras, Lisa J., Woody, Neil M., Jennings, Michael C., and Puddephatt, Richard J.
- Subjects
- *
ORGANOPLATINUM compounds , *BROMINE compounds , *POLYMERS , *BROMIDES , *SUPRAMOLECULAR chemistry , *OLIGOMERS - Abstract
The oxidative addition of alkyl bromides RCH2Br (R = C5H4N, C6H4CN, CH2C6H4CO2H, or CH2C6H4CH2CO2H) to dimethylplatinum(II) complexes [PtMe2(LL)] (LL = diimine ligand) gives the corresponding organoplatinum(IV) complexes [PtBrMe2(CH2R)(LL)] containing functionality in the alkyl group RCH2. The pyridyl derivatives can be protonated, while abstraction of the bromide ligand from [PtBrMe2(CH2R)(LL)] can form cationic complexes, which can react with water or form oligomers by self-assembly. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
39. Organoplatinum(IV) complexes with functional alkyl groups and their use in supramolecular chemistry1.
- Author
-
Au, Richard H. W., Findlay-Shirras, Lisa J., Woody, Neil M., Jennings, Michael C., and Puddephatt, Richard J.
- Subjects
ORGANOPLATINUM compounds ,BROMINE compounds ,POLYMERS ,BROMIDES ,SUPRAMOLECULAR chemistry ,OLIGOMERS - Abstract
Copyright of Canadian Journal of Chemistry is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2009
- Full Text
- View/download PDF
40. Determination of Platinum and Palladium in Geological Samples by Inductively Coupled Plasma-Atomic Emission Spectrometry after Preconcentration with Immobilised Nanometric Titanium Dioxide.
- Author
-
Pei Liang, Ehong Zhao, and Rui Liu
- Subjects
- *
PLATINUM group , *PALLADIUM , *INDUCTIVELY coupled plasma atomic emission spectrometry , *SILICA gel , *IONS , *TITANIUM dioxide - Abstract
A new method has been developed for the determination of platinum and palladium based on separation and preconcentration with a microcolumn packed with nanometric TiO2 immobilised on silica gel (immobilised nanometric TiO2) prior to their determination by inductively coupled plasma-atomic emission spectrometry. The optimum experimental parameters for the preconcentration of Pt and Pd, such as the pH of the sample solution, its flow rate and volume, the type and concentration of eluent and interfering ions, have been investigated. Platinum and Pd could be quantitatively retained by immobilised nanometric TiO2 in the pH range 6–8, then eluted completely with 2.0 ml of 3% m/v thiourea in 1.0 mol l−1 HNO3. The detection limits of this method for Pt and Pd were 12 and 7. 6 ng l−1 with an enrichment factor of 100, and the relative standard deviations were 4.7% and 3.3% at the 10 ng ml−1 level. The method has been applied for the determination of Pt and Pd in geological samples with satisfactory results. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
41. Synthesis of platinum(II) cyclometallated compounds derived from imines containing pyridyl or pyrimidyl groups.
- Author
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Crespo, Margarita, Anderson, Craig M., and Tanski, Joseph M.
- Subjects
- *
LIGANDS (Chemistry) , *ACETONE , *IMINES , *METHANOL , *CRYSTALLOGRAPHY - Abstract
The reaction of compounds [Pt2Me4(µ-SMe2)2] and cis-[PtPh2(SMe2)2] with ligands 4-(2′-C5H4N)C6H4 CHN CH2CH2NMe2 (1a) and 4-(3′,5′-C4H3N2)C6H4CHNCH2CH2NMe2 (1b) carried out in acetone at room temperature produced compounds in which the imines act as bidentate [N,N′] ligands. Analogous compounds could be obtained in refluxing methanol when cis-[PtCl2(DMSO)2] was used as starting material. The corresponding cyclometallation processes leading to platinum(II) compounds with a tridentate [C,N,N′] ligand took place under different reaction conditions, except for metallation of 1a with cis-[PtPh2(SMe2)2], which could not be achieved. All compounds were characterized by usual techniques and [PtMe{4-(3′,5′-C4H3N2)C6H3CHNCH2CH2NMe2}] (3bMe) was also characterized crystallographically. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
42. Synthesis and structures of palladium(II) and platinum(II) complexes containing heterocyclic thiolate ligands formed by cycloaddition reactions of coordinated azides.
- Author
-
Fleischer, Angela, Roller, Alexander, Arion, Vladimir B., Keppler, Bernhard K., and Mohr, Fabian
- Subjects
- *
PHOSPHINE , *LIGANDS (Chemistry) , *RING formation (Chemistry) , *TETRAZOLES , *MOLECULAR structure , *X-rays - Abstract
The phosphine-stabilized azido complexes [M(N3)2(PTA)2] (M = Pd, Pt; PTA = 1,3,5-triaza-7-phosphaadamantane) were prepared in high yields by a ligand exchange reaction from cis-[Pd(N3)2(tmeda)] and cis-[Pt(N3)2(cod)], respectively. The Pd and Pt complexes [M(N3)2(PTA)2] undergo cycloaddition reactions with various isothiocyanates to give complexes containing anionic, S-coordinated tetrazole-thiolate ligands of the type trans-[M(SCN4R)2(PTA)2] (M = Pd, Pt; R = Et, allyl, Me, Ph). The molecular structures of several of these derivatives were determined by X-ray crystallography. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
43. Pt(2,2'-bpy)(O2CCF3)2 as a terminator for [Ag(O2CCF3)]n aggregates — Syntheses and structures of heterobimetallic PtIIAgI complexes.
- Author
-
Yi Sun, Ross, Bryan, Rui-Yao Wang, and Suning Wang
- Subjects
- *
STOICHIOMETRY , *METAL ions , *MOLECULES , *NUCLEAR isomers , *IONS , *CRYSTALS , *X-ray diffraction - Abstract
The reactions between Pt(2,2′-bpy)(O2CCF3)2 and Ag(O2CCF3) have been found to consistently produce heterobimetallic complexes where the [Pt(2,2′-bpy)]2+ unit acts as a terminator for various [Ag(O2CCF3)]n aggregates. The stoichiometry and the structure of the heterobimetallic complex obtained is dependent on the ratio of Pt(2,2′-bpy)(O2CCF3)2 and Ag(O2CCF3) used in the synthesis. When a 1:1 ratio of Pt/Ag was used, a heteronuclear complex Pt2Ag2(2,2′-bpy)2(O2CCF3)6 (1a) was obtained where the four metal ions have a linear Pt-Ag-Ag-Pt arrangement. Molecules of 1a stack in the crystal lattice via intermolecular Pt···Pt interactions to form a linear 1D extended structure. A structural isomer of 1a, Pt2Ag2(2,2′-bpy)2(O2CCF3)6 (1b), where the four metal ions have an L-shaped arrangement was also identified and characterized, which forms a zig-zag 1D extended structure via intermolecular Pt···Pt interactions. When the 1:2 and the 1:3 ratios of Pt/Ag were used, heteronuclear complexes Pt2Ag4(2,2′-bpy)2(O2CCF3)8 (2) and Pt2Ag6(2,2′-bpy)2(O2CCF3)10 (3) were isolated, respectively, where the Ag(I) ions form cyclic structures with the Pt(2,2′-bpy)(O2CCF3)2 units at the terminal positions. Further increase of the amount of Ag(O2CCF3) used in the synthesis did not lead to the isolation of larger aggregates. The structures of compounds 1a, 1b, 2, and 3 were determined by single-crystal X-ray diffraction analyses. 19F NMR spectroscopic analysis established that these heterobimetallic complexes undergo dynamic exchanges in solution. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
44. Synthesis and evaluation of the in vitro DNA-binding properties of chiral cis-dichloro(pyridyloxazoline)platinum(II) complexes.
- Author
-
Dodd, David W., Toews, Heather E., Trevail, Michael J., Jennings, Michael C., Hudson, Robert H. E., and Jones, Nathan D.
- Subjects
- *
CHIRALITY , *DNA , *CISPLATIN , *DNA-binding proteins , *POLYACRYLAMIDE gel electrophoresis - Abstract
A series of chiral cis-dichloro(pyridyloxazoline)platinum(II) and palladium(II) complexes were synthesized and their reactivity towards a defined sequence of single-stranded and double-stranded DNA was investigated in comparison to cisplatin. The compounds differed in the nature and absolute configuration of the substituent at the C4 position of the oxazoline ring. The DNA-binding ability of these compounds was evaluated by HPLC analysis, post metal exposure, of enzymatic digests of an undecamer duplex containing one putative metallation site. Polyacrylamide gel electrophoresis (PAGE) and thermal denaturation confirmed the results of the HPLC analysis, which showed that the stereochemistry and character of the substituent at the C4 position of the oxazoline ring had little effect on DNA binding, possibly due to the formation of monofunctional adducts. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
45. Interactions among 18O2, C2H4, and NO on the surface of stepped Pt(332).
- Author
-
Yuhai Hu and Griffiths, Keith
- Subjects
- *
FOURIER transform spectroscopy , *SPECTRUM analysis , *DISSOCIATION (Chemistry) , *TEMPERATURE , *THERMAL analysis - Abstract
The influence of co-adsorbed 18O2 (18O) on NO/C2H4 reactions on the surface of stepped Pt(332) has been investigated using Fourier transform infrared reflection–absorption spectroscopy (FTIR-RAS) and thermal desorption spectroscopy (TDS). The presence of 18O2 (18O) results in changes in C2H4 dissociation behavior, with formation of ethylidyne taking place at surface temperature much higher than that in the absence of 18O2 (18O). Pre-annealing 18O2/C2H4 co-adlayers to 250 and 300 K does not lead to significantly different IR spectra, but a variety of spectra are observed when the 250 K and 300 K 18O/C2H4 co-adlayers are further exposed to 0.8 L NO at 90 K, depending on the 18O2 pre-exposure. NO adsorption in bridge sites, both on steps and on terraces is more significantly suppressed for the co-adlayers in which 18O2/C2H4 is pre-annealed to 250 K. This site-blocking effect is enhanced with increasing 18O2 exposure. However, no new surface species, which are intermediates for N2 production, are detected. Thermal desorption spectra indicate that various species are produced, but only N2 and H2 desorption have intensities that can be reliably analyzed (that is to be able to quantitatively elucidate how the yields of these two species vary with change in the ratios of NO to C2H4 and 18O2). Desorption of both N2 and H2 is more strongly dependent on 18O2 exposure than on the temperature to which 18O2/C2H4 adlayers are pre-annealed. The presence of 18O2, irrespective of the dosing sequence, suppresses N2 desorption, but this effect is much weaker when 18O2 is post-dosed. For the case with 18O2 pre-dosed, irrespective of the annealing temperature (250 K or 300 K), N2 desorption is greatly suppressed at an 18O2 exposure of 0.2 L, but thereafter remains almost unchanged with increasing 18O2 exposure from 0.4 to 1.6 L. This feature of N2 desorption is explained by the restoration of the adsorption of NO onto steps and the subsequent NO dissociation on these sites. In contrast, H2 desorption decreases continuously and disappears at 0.8 L 18O2 and higher. It is concluded that the presence of 18O2 in the reaction of NO with C2H4 on the surface of Pt(332) does not play any role of activating the surface reactants.Key words: NO, platinum, C2H4, deNOx, hydrocarbon, selective catalytic reduction. Faisant appel à la spectroscopie de réflexion–absorption infrarouge en transformée de Fourier et à la spectroscopie de désorption thermique, on a étudié l’influence des entités coadsorbées 18O2 (18O) sur les réactions du NO et du C2H4 sur la surface de Pt(332) en escalier. La présence de 18O2 (18O) provoque des changements dans le comportement dissociatif du C2H4 avec une formation d’éthylidyne qui se fait sur la surface à une température beaucoup plus élevée qu’en l’absence de 18O2 (18O). À des températures allant de 250 et 300 K, la préannellation de couches coadsorbées de 18O/C2H4 ne conduit pas à des spectres IR qui présenteraient des différences significatives, mais dépendant de la nature de la préexposition au 18O2, on observe une variété de spectres lorsque les couches de 18O/C2H4 qui ont été coadsorbées à des températures allant de 250 et 300 K sont exposées à 0,8 L de NO à 90 K. L’adsorption du NO sur les sites pontés, tant sur les marches que sur les terrasses est beaucoup plus supprimé pour les couches coadsorbées dans lesquelles la préannellation du 18O/C2H4 a été faite à 250 K. Cet effet de blocage de site est rehaussé avec une augmentation de l’exposition au 18O2. Toutefois, on n’a pas détecté de nouvelles espèces à la surface qui pourraient conduire à la production de N2. Les spectres de désorption thermiques indiquent qu' [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
46. Chemical vapor deposition of nickel-group metals on multiwall carbon nanotubes.
- Author
-
Feng, Maoqi and Puddephatt, Richard J.
- Subjects
- *
CHEMICAL vapor deposition , *NICKEL , *PALLADIUM , *PLATINUM , *METALLIC films - Abstract
Chemical vapor deposition (CVD) of Ni, Pd, and Pt films and of Ni/Pd and Pd/Pt bimetallic films on multiwall carbon nanotubes (MWCNTs) can be effected at low temperature if the nanotubes are pretreated by CVD of titanium carbide. In the absence of the pretreatment, the CVD leads to formation of isolated nanoparticles of the nickel-group metals. The metallized MWCNTs are curved or kinked, as a result of the interaction with the metal. Preliminary oxidation of the carbon nanotubes allows easier metallization, and the bending of the metallated nanotubes is not observed in this case. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
47. Inté^et du dosage du platine en cancérologie clinique.
- Author
-
Bardina, Christophe, Huet, Estelle, Tafzi, Naïma, and Declèves, Xavier
- Subjects
PLATINUM ,PHARMACOLOGY ,CISPLATIN ,ANTINEOPLASTIC agents ,DRUG monitoring - Abstract
Copyright of Revue Francophone des Laboratoires is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2007
- Full Text
- View/download PDF
48. Organogold(I) macrocycles and [2]catenanes containing pyridyl and bipyridyl substituents — Organometallic catenanes as ligands.
- Author
-
Habermehl, Nicolle C., Mohr, Fabian, Eisler, Dana J., Jennings, Michael C., and Puddephatt, Richard J.
- Subjects
- *
ORGANOGOLD compounds , *MACROCYCLIC compounds , *CATENANES , *ORGANOMETALLIC chemistry , *PLATINUM - Abstract
The synthesis of achiral gold(I) macrocycles [RCH(4-C6H4OCH2C≡CAu)2(µ-Ph2PZPPh2)] and the corresponding chiral gold(I) [2]catenanes, bearing substituents R = 2-pyridyl, 4-pyridyl, and 4-(2,2′-bipyridyl), is reported. The gold(I) compounds form by self-assembly on reaction of oligomeric digold(I) diacetylides [{RCH(4-C6H4OCH2C≡CAu)2}n] or the isocyanide complexes [RCH(4-C6H4OCH2C≡CAuC≡N-t-Bu)2] with diphosphine ligands Ph2PZPPh2, Z = CC or (CH2)n with n = 2–5, or on reaction of [Au2(O2CCF3)2(µ-Ph2PZPPh2)] with diacetylenes RCH(4-C6H4OCH2C≡CH)2 in the presence of a base. The equilibrium between macrocycles and chiral [2]catenanes in solution was established by NMR spectroscopy, while the structures of several [2]catenanes in the solid state were established crystallographically. The coordination of the gold(I) compounds with R = 4-(2,2′-bipyridyl) to platinum(IV), by formation of the corresponding [PtIMe3(bipy)] units, is established, showing that organometallic [2]catenanes can act as ligands. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
49. A computational examination of helical perfluoroalkane conformations and implications for the adsorption of perfluoroalkanes on platinum(111) surfaces
- Author
-
Golden, William G. and Zoellner, Robert W.
- Subjects
- *
THERMAL desorption , *SURFACE chemistry , *ADSORPTION (Chemistry) , *MOLECULES , *MONOMOLECULAR films - Abstract
Abstract: The two lowest-energy conformers of perfluorohexane and perfluoroheptane were investigated at the Hartree–Fock RHF/6-31G* level and the structures, properties, and vibrational frequencies determined. The lowest-energy conformers of perfluorohexane were found to differ by 8.600 kJ mol-1 (2.055 kcal mol–1) at this level of theory, while the lowest-energy conformers of perfluoroheptane differed by 8.662 kJ mol–1 (2.070 kcal mol–1). In addition, a transition state for the interconversion between the two lowest-energy conformers of perfluorohexane was investigated at the RHF/6-31G* level, and was found to lie 13.247 kJ mol–1 (3.166 kcal mol–1) above the energy of the lowest-energy conformer, while a transition state for the equivalent interconversion between the perfluoroheptane conformers was 15.279 kJ mol–1 (3.652 kcal mol–1) above the energy of the lowest-energy conformer. These results have been used to interpret previously published thermal desorption and infrared reflection–absorption spectroscopic data for the monolayer and sub-monolayer adsorption of perfluorocarbon molecules on a single-crystal Pt(111) surface under ultra-high vacuum conditions. To cite this article: W.G. Golden et al., C.R. Chimie 7 (2004) . [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
50. In vitro and in vivo studies of neutral cyclometallated complexes against murine leukæmias.
- Author
-
Edwards, Gavin L., Black, David St. C., Deacon, Glen B., and Wakelin, Laurence P. G.
- Subjects
- *
DIMERS , *LIGANDS (Chemistry) , *PYRROLES , *PYRIDINE , *PALLADIUM compounds , *PLATINUM compounds - Abstract
Cyclometallated µ-halogeno dimers derived from nitrogen donor ligands (1-phenylpyrazoles, 2-phenylpyridine, and 1-(2′-pyridyl)indole) were treated with unidentate nitrogen and phosphorus donor ligands to give a series of neutral monomeric palladium(II) and platinum(II) complexes. An initial prescreen of the complexes against the mouse lymphoid leukæmia cell line L1210 indicated that the complexes exhibited growth inhibitory activity over a relatively wide concentration range. Two factors that gave rise to increased activity were steric hindrance about the metal centre resulting from hindered ligands such as 2,6-dimethylpyridine, or the presence of a phosphorus donor ligand. Little correlation between palladium and platinum complexes was noted. Four complexes were selected for further in vivo study and, while none of the palladium complexes showed more than marginal activity against P388 leukæmia at doses below toxic levels, one platinum complex with a hindered metal centre did display significant antitumour activity against this model. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
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