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Roukoss C Fiddy S de Mallmann A Rendón N Basset JM Kuntz E Copéret C 《Dalton transactions (Cambridge, England : 2003)》2007,(47):5546-5548
Well-defined Fe(II) isolated sites are obtained by reaction of diaryl-N,N'-diazadiene bis(neosilyl) iron (1) with an aerosil silica, SiO(2-(700)). This system can be used as a precursor for the catalytic oxidation of cyclohexene into cyclohexene oxide, cyclohexenol and cyclohexenone in the presence of H(2)O(2). 相似文献
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Franois Basset Alain Lefrant Thierry Pascal Bernard Gallot Bernard Sillion 《先进技术聚合物》1998,9(3):202-209
Highly crystalline polyimide powders were prepared from diluted solutions of polyamic acid in N-methyl-2-pyrrolidone (NMP) which were cured at 200°C for 4 hr with a high heating rate. The chemical structures of the repetitive units were chosen to obtain rigid polymeric backbones precluding any solubility in polar aprotic solvents. Therefore the starting polyamic acids were produced by polycondensation from an equimolar ratio of the following pairs of monomers: pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA); 3,3′,4,4′-biphenyl tetracarboxylic dianhydride and ODA; PMDA and p-phenylenediamine. After optimizing the reaction conditions, the resulting powders were first characterized by scanning electronic microscopy and granulometric analysis. Well-divided particles with a spherulitic shape and average particle size of 5 μm were observed. The X-ray diffraction patterns and the solid-state 13C nuclear magnetic resonance spectra together revealed a highly organized structure. The degree of imidization of the powder is nearly complete as demonstrated by Fourier transform infrared analysis and the inherent viscosity after dissolution in concentrated sulfuric acid is about 0.8 dl/g. © 1998 John Wiley & Sons, Ltd. 相似文献
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Synthesis,Physical Properties and Application of a Series of New Polyoxometalate-Based Ionic Liquids
Yohan Martinetto Salom Basset Bruce Pgot Catherine Roch-Marchal Franck Camerel Jelena Jeftic Betty Cottyn-Boitte Emmanuel Magnier Sbastien Floquet 《Molecules (Basel, Switzerland)》2021,26(2)
This paper deals with the preparation and the characterization of four new ionic liquids resulting from the pairing of various polyoxotungstates or polyoxomolybdates with the cation trihexyltetradecylphosphonium. The physical properties measured by different techniques evidence that the viscosity and the rheological behaviors of such POM-based ionic liquids, POM-ILs, strongly depend on the nature of the POM, especially its charge. Playing on the nature of the POM, we can indeed obtain Newtonian liquids or some much more viscous materials exhibiting characteristics of resins or pseudo-plastics. In a second part of this study, the potentialities of using such materials both as solvent and catalyst for the oxidation of a series of alcohols are presented as proof of concept. This part highlights great differences in strength and selectivity as a function of the POM-IL used. Furthermore, a very simple way to recycle the catalyst is also presented. 相似文献
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The achievement of a structure–activity relationship for heterogeneous catalysts is a desirable step for improving existing catalysts or for predicting new catalytic reactions. This article reviews the use of silsesquioxanes (POSS) organometallic complexes as molecular models for silica-grafted catalytic centers. It will show that POSS complexes, within some limits, have substantially contributed to gaining better molecular-level understanding of surface reactions and catalysts activity. 相似文献
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6-(2,4-Dioxopentyl)-2,2-trimethyl-4H-1,3-dioxin-4-one on reflux in toluene gave MeCOCH2COCH2COCHCO, which cyclized to 6-(2-oxopropyl)-4-hydroxy-2H-pyran-2-one or was trapped with alcohols to produce resorcylate esters. The method was used for the synthesis of both enantiomers of montagnetol and erythrin. 相似文献