Zeolite nanoparticles (H-ZSM5) as a highly efficient, green, and reusable heterogeneous catalyst for selective oxidation of sulfides to sulfoxides under mild conditions
Publication date: Available online 9 June 2018Source: Comptes Rendus ChimieAuthor(s): Amin Rostami, Noosheen Saedmocheshi, Zeinab ShirvandiAbstractH-ZSM5 is applied as an efficient, highly reusable, and heterogeneous catalyst for the oxidation of sulfides to sulfoxides using 30% H2O2 under solvent-free conditions at room temperature. A variety of aromatic and aliphatic sulfides with different functional groups were successfully oxidized with good to excellent yields in short reaction times. The catalyst can be easily recovered by simple filtration and recycled for several consecutive runs without any significant loss of it...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Tris-hydroxymethylaminomethane (THAM): An efficient organocatalyst in diversity-oriented and environmentally benign synthesis of spirochromenes
Publication date: Available online 10 June 2018Source: Comptes Rendus ChimieAuthor(s): Supriya S. Khot, Prashant V. Anbhule, Uday V. Desai, Prakash P. WadgaonkarAbstractTris-hydroxymethylaminomethane has been demonstrated to be an efficient organocatalyst in diversity-oriented synthesis of medicinally prevalent spirochromenes by one-pot, three-component reactions between isatins, malononitrile, and enolizable CH acids like dimedone, 4-hydroxycoumarin, 4-hydroxy-N-methylquinolin-2-one, or in situ generated 2-methylpyrazolon-2-one. Biodegradability and extremely low cost of the catalyst are the noteworthy features of this ch...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
The power of synthesis towards new materials
Publication date: Available online 14 June 2018Source: Comptes Rendus ChimieAuthor(s): Michael Veith, Pierre Braunstein (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Microscopic models of spin crossover
Publication date: Available online 15 June 2018Source: Comptes Rendus ChimieAuthor(s): Ján Pavlik, Jorge LinaresAbstractThe basic model for thermal spin crossover (SCO) is discussed in its microscopic and thermodynamic formulation. Compared to the basic model, its more elaborated forms formulated in course of almost 50 years are briefly reviewed with emphasis on their additional features. A separate section is devoted to the newer developments in the field of modelling of the SCO nanoparticles. The presentation of models is led in a comparative way to provide an accessible outline of the foundations of modern theoretical ...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Nanostructured ternary composites of PPy/CNT/NiFe2O4 and PPy/CNT/CoFe2O4: Delineating and improving microwave absorption
Publication date: Available online 19 June 2018Source: Comptes Rendus ChimieAuthor(s): Erfan Ghashghaei, Somayyeh Kheirjou, Sara Asgari, Hanif KazerooniAbstractTwo different ternary nanocomposites, PPy/CNT/CoFe2O4 and PPy/CNT/NiFe2O4, were synthesized by in situ polymerization method. The resulting composites were characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. They were evaluated with the aim of investigating microwave absorption properties. The results showed that the value of microwave refl...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Imidazolinone and triazine herbicides in soils in relation to the complexes formed with Cu(II) ions
In conclusion, crops treated with such herbicides in conjunction with Cu(II) salts experience a decrease in its persistence and effectiveness. In addition, the herbicides and the copper ions may pass to the phreatic layer of the soil, increasing the chance of pollution.Graphical abstract (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Hexavalent chromium quantification in solution: Comparing direct UV–visible spectrometry with 1,5-diphenylcarbazide colorimetry
Publication date: Available online 22 June 2018Source: Comptes Rendus ChimieAuthor(s): Arnaud Sanchez-Hachair, Annette HofmannAbstractQuantification of Cr(VI) in an aqueous solution is conducted by direct UV–visible spectrophotometry based on the yellow coloring of the chromate ion. Measurements show that absorption follows the Beer–Lambert law over a wide range of concentrations. At pH below the pKa of 6.4 (HCrO4−/CrO4−2), the absorption maximum lies at 350 nm wavelength and the linear range spans from 0.5 to 100 mg Cr(VI)/L; above the pKa (pH 6.4), the absorption maximum is 373 nm and linearity occurs in the r...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Surface reactivity of uranium hexafluoride (UF6)
Publication date: Available online 23 June 2018Source: Comptes Rendus ChimieAuthor(s): Bertrand Morel, Ania Selmi, Laurent Moch, Jean-Michel Hiltbrunner, Mickael Achour, Rachid Benzouaa, Aurélien Bock, Laurent Jouffret, Pierre Bonnet, André Hamwi, Marc DuboisAbstractThe present article reviews a selection of results obtained in the AREVA/CNRS/UCA joint research laboratory. It focuses on interfaces formed by uranium hexafluoride (UF6) with chemical filter (purification), carbon (UF6 storage), and metallic substrate (corrosion). As a matter of fact, along the nuclear fuel cycle, metallic surfaces of the fluorination reacto...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Réaction pseudo-multicomposants entre le glutaconate de diméthyle et des aldéhydes aromatiques induite par le bromure de phénylzinc : accès domino à des dihydropyranones 2,3,5-trisubstituées
Publication date: Available online 28 June 2018Source: Comptes Rendus ChimieAuthor(s): Erwan Le Gall, Marc Presset, Éric Léonel, Pascal RetailleauAbstractPhenylzinc bromide enables a pseudo three-component reaction of methyl glutaconate and aromatic aldehydes. Unsaturated trisubstituted δ-valerolactones (dihydropyranones) are obtained in fair to good yields by an aldol/aldol/elimination/lactonization domino process that allows the formation of four new bonds in a single step. A putative reaction mechanism is proposed.RésuméLe bromure de phénylzinc induit une pseudo-réaction à trois composants entre le glutaconate d...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Immobilization of palladium nanoparticles as a recyclable heterogeneous catalyst for the Suzuki–Miyaura coupling reaction
Publication date: July 2018Source: Comptes Rendus Chimie, Volume 21, Issue 7Author(s): Ramin Ghorbani-Vaghei, Narges Sarmast, Farid RahmatpourAbstractThis work describes the synthesis of Pd nanoparticles that are stabilized on CaAl-layered double hydroxide functionalized with Tris (tris(hydroxymethyl)aminomethane). The synthesized catalyst is characterized by several different analyses and has been successfully applied to the Suzuki–Miyaura reaction.Graphical abstract (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Reprogramming the chemical reactivity of iron in cancer stem cells
Publication date: July 2018Source: Comptes Rendus Chimie, Volume 21, Issue 7Author(s): Tatiana Cañeque, Sebastian Müller, Anne Lafon, Fabien Sindikubwabo, Antoine Versini, Lou Saier, Manon Barutaut, Christine Gaillet, Raphaël RodriguezAbstractCancer stem cells (CSCs) have been shown to be refractory to conventional therapeutic agents, can promote metastasis, and have been linked to cancer relapse. Salinomycin can selectively kill CSCs. We have shown that salinomycin derivatives accumulate in lysosomes and sequester iron in this organelle. As a result, accumulation of iron leads to the production of reactive oxygen speci...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Editorial Board - French
Publication date: July 2018Source: Comptes Rendus Chimie, Volume 21, Issue 7Author(s): (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Sommaire / Contents
Publication date: July 2018Source: Comptes Rendus Chimie, Volume 21, Issue 7Author(s): (Source: Comptes Rendus Chimie)
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Solvent effects in the aza-Michael addition of anilines
Publication date: July 2018Source: Comptes Rendus Chimie, Volume 21, Issue 7Author(s): Alena Fedotova, Evgeniy Kondrashov, Julien Legros, Jacques Maddaluno, Alexander Yu. RulevAbstractThe aza-Michael addition of functionally substituted anilines to enoates is significantly affected by the hydrogen bond donor ability of the solvent. Very polar protic fluorinated alcohols (hexafluoroisopropanol and trifluoroethanol) favor the addition of weak nucleophiles, whereas these solvents are no longer required for anilines bearing additional OH or NH2 group.RésuméL'adition d'aza-Michael d'anilines fonctionnalisées sur des énoates...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
Mn(III)-porphyrin/graphene oxide nanocomposite as an efficient catalyst for the aerobic oxidation of hydrocarbons
In this study, manganese porphyrin was grafted on the surface of graphene oxide nanosheets via covalent bonding to produce a heterogeneous catalyst. The prepared nanocomposite was characterized using X-ray diffraction, UV–vis spectroscopy, scanning electron microscopy, Fourier transform infrared, and thermogravimetric analysis. Atomic absorption spectroscopy was also used to determine the amount of the loaded catalyst. The catalytic efficiency of the immobilized Mn-porphyrin was investigated for the aerobic oxidation of alkenes and saturated alkanes in acetone under mild reaction conditions. The prepared heterogenized ca...
Source: Comptes Rendus Chimie - July 5, 2018 Category: Chemistry Source Type: research
