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  Subjects -> CHEMISTRY (Total: 931 journals)
    - ANALYTICAL CHEMISTRY (58 journals)
    - CHEMISTRY (663 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (27 journals)
    - INORGANIC CHEMISTRY (43 journals)
    - ORGANIC CHEMISTRY (48 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (663 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 15)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 31)
ACS Applied Polymer Materials     Hybrid Journal  
ACS Catalysis     Hybrid Journal   (Followers: 55)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 22)
ACS Combinatorial Science     Hybrid Journal   (Followers: 21)
ACS Macro Letters     Hybrid Journal   (Followers: 29)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 46)
ACS Nano     Hybrid Journal   (Followers: 378)
ACS Photonics     Hybrid Journal   (Followers: 15)
ACS Symposium Series     Full-text available via subscription   (Followers: 1)
ACS Synthetic Biology     Hybrid Journal   (Followers: 25)
Acta Chemica Iasi     Open Access   (Followers: 6)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 8)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 65)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 88)
Advances in Chemistry     Open Access   (Followers: 29)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Environmental Chemistry     Open Access   (Followers: 8)
Advances in Enzyme Research     Open Access   (Followers: 11)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 29)
Advances in Nanoparticles     Open Access   (Followers: 19)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Polymer Science     Hybrid Journal   (Followers: 49)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 13)
Aerosol Science and Engineering     Hybrid Journal  
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 5)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 8)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 3)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 71)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 22)
American Journal of Chemistry     Open Access   (Followers: 35)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 14)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 37)
Angewandte Chemie     Hybrid Journal   (Followers: 191)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 289)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 8)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 15)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 26)
Applied Surface Science     Hybrid Journal   (Followers: 33)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access   (Followers: 2)
Atomization and Sprays     Full-text available via subscription   (Followers: 5)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 4)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 403)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 7)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Hybrid Journal   (Followers: 25)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 184)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 91)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 17)
Biosensors     Open Access   (Followers: 3)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 25)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 12)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Research     Hybrid Journal   (Followers: 24)
Carbon     Hybrid Journal   (Followers: 73)
Catalysis for Sustainable Energy     Open Access   (Followers: 10)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 10)
Catalysis Science and Technology     Hybrid Journal   (Followers: 10)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 14)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 2)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 23)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 76)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 27)
Chemical Physics Letters : X     Open Access   (Followers: 2)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 23)
Chemical Reviews     Hybrid Journal   (Followers: 233)
Chemical Science     Open Access   (Followers: 33)
Chemical Technology     Open Access   (Followers: 49)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 21)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Full-text available via subscription   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 191)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 17)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 22)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 46)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 284)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 21)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 12)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Clay Minerals     Hybrid Journal   (Followers: 10)
Cogent Chemistry     Open Access   (Followers: 2)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 24)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 8)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 13)
Computational Chemistry     Open Access   (Followers: 3)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 4)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 7)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 8)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 6)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 10)

        1 2 3 4 | Last

Similar Journals
Journal Cover
Comptes Rendus Chimie
Journal Prestige (SJR): 0.438
Citation Impact (citeScore): 2
Number of Followers: 0  
 
  Full-text available via subscription Subscription journal
ISSN (Print) 1631-0748
Published by Elsevier Homepage  [3181 journals]
  • Oxygen demand of waters associated with the use of sewage sludge compost
           and limestone outcrop as a filtration system
    • Abstract: Publication date: Available online 12 March 2019Source: Comptes Rendus ChimieAuthor(s): Ana Pérez Gimeno, Jose Navarro Pedreño, María Belén Almendro Candel, Ignacio Gómez Lucas, Antonis A. Zorpas The use of composted sewage sludge (SW) and limestone outcrop residue (LR) as water filter systems has been tested. An experimental design based on the use of columns (0–30 cm) was used with both wastes under a heavy irrigation regime (2000 mL/week) for 12 weeks. Half of them were irrigated with nonsaline water (NS) and the others with saline water (S). Four treatments combining the quality of the irrigation water and wastes were obtained: SW-NS, SW-S, LR-NS, and LR-S. The chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and suspended solids were measured. The results indicated that COD and BOD5 were higher in the treatments with SW than LR, whereas saline irrigation did not modify BOD5 compared with nonsaline irrigation, but COD increased in both wastes. The environmental concern due to organic matter displacement in waters should be taken into account when using these wastes, especially SW. Moreover, the use of S may increase the COD with the consequent risk for natural water. When designing a filter system considering inert and organic matter, SW and LR can be effective materials and should be taken into consideration.
       
  • External mass transport process during the adsorption of fluoride from
           aqueous solution by activated clay
    • Abstract: Publication date: Available online 6 March 2019Source: Comptes Rendus ChimieAuthor(s): Sami Guiza, Houda Hajji, Mohamed Bagane The removal of fluoride ions from an aqueous solution using a modified sulfuric acid clay was studied in batch adsorption. The adsorption kinetics were studied to identify the retention mechanisms. For kinetics study, perfectly stirred batch experiments were carried out after the adjustment of the parameters influencing the system, such as the pH, the adsorbent dosage, the initial concentration of fluoride ions, and the stirring speed. It appears that the rate of fluoride ion removal (1) increased with the mass of adsorbent and the stirring speed, and (2) decreased with the initial fluoride ion concentration. The experimental results were adjusted according to kinetic equations representing four external transport models. The latter were used to calculate the external mass transfer coefficient, kf. The results showed that this coefficient is in the range of 10−5–10−4 m s−1.RésuméNous avons étudié dans ce travail la cinétique d'adsorption en solution aqueuse des ions fluorure sur un matériau argileux modifié par l'acide sulfurique dans un adsorbeur en batch. L'influence de certains paramètres, comme le pH de la solution, la masse d'argile en solution, la concentration initiale des ions fluorure et la vitesse d'agitation, a été étudiée. Les résultats obtenus prouvent que : (i) la cinétique augmente avec la masse d'argile et la vitesse d'agitation et (ii) décroît avec la concentration initiale en ions fluorure. Quatre modèles de transport externe ont été étudiés et ont montré que l'ordre de grandeur du coefficient kf se trouve dans la gamme entre 10−5 et 10−4 m s−1.
       
  • Voltammetric oxidation of acetophenone derivatives and benzophenone in
           acetonitrile on a platinum and glassy carbon electrode
    • Abstract: Publication date: Available online 28 February 2019Source: Comptes Rendus ChimieAuthor(s): László Kiss, Sándor Kunsági-Máté The voltammetric oxidation of five para-substituted acetophenone derivatives (containing nitro, chloro, bromo, methyl and hydroxyl groups as substituents) and that of benzophenone was studied on a platinum and glassy carbon electrode in acetonitrile media. Electrode passivation was observed in the case when all selected compounds are on a glassy carbon electrode; an oxidation peak appeared between 2.5 and 3 V. The voltammograms of 4′-hydroxyacetophenone showed an additional peak around 2 V, which may be associated with the oxidation of the phenol moiety. In the case of a platinum electrode, no relevant peaks appeared on the voltammograms, reflecting the absence of passivation. The use of a redox probe 1,4-dihydroxybenzene showed that the glassy carbon electrode, after cyclization in the solutions of the outlined compounds, has higher sensitivity towards the oxidation product (1,4-benzoquinone) of this compound.
       
  • Complexes featuring N-heterocyclic carbenes with bowl-shaped
           wingtips
    • Abstract: Publication date: Available online 27 February 2019Source: Comptes Rendus ChimieAuthor(s): Hamzé Almallah, Mélodie Nos, Virgile Ayzac, Eric Brenner, Dominique Matt, Christophe Gourlaouen, Mohamad Jahjah, Akram Hijazi Three imidazolium salts having their two N-substituents equipped with remote calix[4]arenyl termini have been synthesised and converted into N-heterocyclic carbene (NHC) complexes of the type [PdCl2(NHC)(pyridine)]. An X-ray diffraction study carried out for one of the complexes, namely, trans-[1,3-bis(4-{25,26,27,28-tetrapropyloxycalix[4]aren-5-yl}phenyl)imidazol-2-ylidene](pyridine)palladium(II) dichloride, revealed that in the solid state the complex crystallises as a self-assembled dimer, its components being held together by dispersion forces involving the polyphenoxy units, the pyridine ligands and phenylene rings. This structure provides a new example of the diversity of interactions that may occur in NHC complexes of catalytic relevance, which are thus not limited to intramolecular ones. There was no spectroscopic indication that such interactions also occur in solution.RésuméTrois sels d'imidazolium ayant leurs atomes d'azote substitués par des groupes arylcalixarényle ont été préparés et utilisés pour la synthèse de complexes de type [PdCl2(NHC)(pyridine)] (NHC = carbène N-hétérocyclique). L'analyse par diffraction des rayons X du complexe trans-[1,3-bis(4-{25,26,27,28-tétrapropyloxycalix [4]arèn-5-yl}phényl)imidazol-2-ylidène](pyridine) dichloropalladium(II) révèle, de manière inattendue, qu'à l'état solide ce composé s'auto-assemble en formant un dimère dont les composantes sont maintenues ensemble par un jeu de forces faibles impliquant des unités phénoxy, les coordinats pyridine et les noyaux phénylène. Cette structure constitue un nouvel exemple de la complexité des phénomènes pouvant contribuer à influencer l'environnement stérique de complexes de carbènes N-hétérocycliques d'intérêt catalytique.
       
  • Insights on the influence of the precursors on the sol–gel synthesis of
           hybrid organic–inorganic saponite-like materials
    • Abstract: Publication date: Available online 27 February 2019Source: Comptes Rendus ChimieAuthor(s): Dylan Chaillot, Jocelyne Miehé-Brendlé, Simona Bennici Lamellar organic–inorganic hybrid materials, especially talc- and saponite-like structures, have been broadly investigated over the past decades because of the combination of the thermal and mechanical properties of the inorganic part with the possibility to finely tune hydrophilic–hydrophobic balance, ion exchange capacity, and properties through the choice of the silicon source. These compounds are generally produced by coprecipitation or hydrothermal synthesis methods, allowing the formation of well-crystallized particles but it is time and energy consuming. Recently, hybrid organic–inorganic lamellar materials have been synthesized using sol–gel method, which is attractive as it is a one-step method performed under mild conditions, with low energy consumption and short formation times. The originality of this research stands in the study of the influence of the reactants on the formation of saponite-like hybrids and especially on the role of the aluminum source in the sol–gel synthesis of hybrid organic–inorganic lamellar materials. The obtained materials have been characterized by X-ray diffraction, Fourier transform infrared, and solid-state nuclear magnetic resonance spectroscopies and thermogravimetric analysis, and it was shown that hydrotalcite-like compounds can be obtained beside saponite-like compounds depending on the aluminum source.RésuméDe nombreuses études ont été menées récemment sur les matériaux hybrides organiques–inorganiques de structure lamellaire, de types talc et saponite, notamment, dans le contexte de la combinaison des propriétés thermiques et mécaniques de la fraction inorganique, d'une part, avec la possibilité d'adapter la balance hydrophile/hydrophobe, la capacité d’échange cationique ainsi que les propriétés associées au choix de la source de silicium, d'autre part. Ces composés sont généralement synthétisés par co-précipitation ou par synthèse hydrothermale, ce qui permet la formation de particules bien cristallisées, mais demande beaucoup de temps et d’énergie. Plus récemment, ces matériaux ont été synthétisés par la méthode sol–gel, qui permet d'obtenir des matériaux de grande pureté en des temps très courts avec une faible nécessité énergétique. L'originalité de ce travail repose sur l’étude de l'influence des réactifs sur la formation de matériaux hybrides organiques–inorganique de structure de type saponite, notamment le rôle de la source d'aluminium dans la synthèse par voie sol–gel de matériaux hybrides organiques–inorganiques de structure lamellaire. Les matériaux synthétisés ont été analysés par DRX, IR-TF, RMN du solide et ATG, ce qui a permis de découvrir que des composés similaires à des hydrotalcites peuvent être obtenus selon la source d'aluminium employée.
       
  • Regioselective palladium-catalyzed Suzuki–Miyaura coupling reaction of
           2,4,6-trihalogenopyrido[2,3-d]pyrimidines
    • Abstract: Publication date: Available online 22 February 2019Source: Comptes Rendus ChimieAuthor(s): Yassine Riadi, Saïd Lazar, Gérald Guillaumet An effective, regioselective, and novel strategy to the access of 2,4,6-trisubstituted pyrido[2,3-d]pyrimidines is developed from the corresponding 2,4,6-trihalogenopyrido[2,3-d]pyrimidine through a Suzuki–Miyaura coupling reaction involving a novel regioselective halogen discrimination.Graphical abstractImage 1
       
  • Preparation and characterization of H3−2(x+y)Mn x Co y PMo12O40
           heteropolysalts. Application to adipic acid green synthesis from
           cyclohexanone oxidation with hydrogen peroxide
    • Abstract: Publication date: Available online 22 February 2019Source: Comptes Rendus ChimieAuthor(s): Sihem Mouanni, Tassadit Mazari, Dahbia Amitouche, Sihem Benadji, Leila Dermeche, Catherine Roch-Marchal, Chérifa Rabia H3−2(x+y)MnxCoyPMo12O40 heteropolysalts (x + y ≤ 3/2 and x, y: 0–1.5) were prepared by a cationic exchange method based on barium sulfate precipitation. Structural and textural properties of salts were examined by several physicochemical techniques such as infrared, scanning electron microscopy-energy dispersive X-ray, and 31P nuclear magnetic resonance spectroscopies, X-ray diffraction diffraction, and thermogravimetric analysis, and their catalytic properties were evaluated in the cyclohexanone oxidation using hydrogen peroxide (30%). The reaction products, adipic, glutaric, succinic, hexanoic, 6-hydroxyhexanoic, 7,7-dimethoxy, and heptanoic acids and 1,1-dimethoxy octane were identified by gas chromatography–mass spectrometry analysis. Only adipic, glutaric, and succinic acids were quantified by chromatography (high-performance liquid chromatography), the other products were noted X. Adipic acid (AA) is the major product for all systems. The effects of molar ratios of catalyst/reactant and cyclohexanol/cyclohexanone, heteropolysalt composition, and reaction duration on AA yield were investigated. The stability of the catalytic system was also examined. H3−2(x+y)MnxCoyPMo12O40 catalysts were found to be efficient for the cyclohexanone oxidation with conversions>95%. Among them, H1Mn0.25Co0.75 exhibits the highest AA yield (75%).RésuméLes hétéropolysels H3−2(x+y)MnxCoyPMo12O40 (x + y ≤3/2 et x, y: 0–1,5) ont été préparés par une méthode d'échange cationique basée sur la précipitation du sulfate de baryum. Les propriétés structurales et texturales des sels ont été examinées par plusieurs techniques physico-chimiques telles que les spectroscopies IR, MEB/EDX et RMN 31P, la diffraction des rayons X et l'analyse TG. Leurs propriétés catalytiques ont été évaluées dans l'oxydation de la cyclohexanone en utilisant le peroxyde d'hydrogène (30%). Les produits de la réaction, acides adipique, glutarique, succinique, hexanoïque, 6-hydroxyhexanoïque, 7,7-diméthoxy, heptanoïque et 1,1-diméthoxy octane, ont été identifiés par analyse GC-MS. Seuls les acides adipique, glutarique et succinique ont été quantifiés par chromatographie (HPLC), les autres produits ont été notés X. L'acide adipique (AA) est le principal produit de la réaction. Les effets des rapports molaires catalyseur/réactif et cyclohexanol/cyclohexanone, de la composition du sel et du temps de réaction sur le rendement en AA ont été étudiés. La stabilité du système catalytique a également été examinée. Les catalyseurs H3−2(x+y)MnxCoyPMo12O40 se sont révélés être efficaces pour l'oxydation de la cyclohexanone avec des conversions>95%. Parmi eux, H1Mn0.25Co0.75 conduit au rendement le plus élevé en AA (75%).
       
  • Development of a new cathode for the electro-Fenton process combining
           carbon felt and iron-containing organic–inorganic hybrids
    • Abstract: Publication date: Available online 22 February 2019Source: Comptes Rendus ChimieAuthor(s): Simona M. Miron, Jocelyne Brendlé, Ludovic Josien, Florence Fourcade, Franck Rojas, Abdeltif Amrane, Lionel Limousy New kinds of electrodes were prepared for implementation in the electro-Fenton process. Based on carbon felt/organic–inorganic talc like hybrid (TLH), the electrodes were successfully prepared by a simple one-step sol–gel procedure at room temperature, from aminopropyltrimethoxysilane, magnesium and iron(III) hexahydrated chlorides, carbon felt, and ethanol. They were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence, thermal analysis, scanning electron microscopy, and solid-state nuclear magnetic resonance. It was shown that the order of carbon felt addition to the prepared solution is a key point to form a thin and homogeneous TLH layer at the surface of the carbon fibers. Also, composites having different Fe/Mg molar ratios can be obtained. The composite containing 100 wt % Fe was successfully tested as an electrode for the electro-Fenton process, because 98% degradation yield was obtained after 4 h of electrolysis. These results show that Fenton's reaction can be achieved with immobilized iron and H2O2 produced at the cathode, which can account for the better degradation yield as compared with 70.5% obtained during electrolysis with a nonmodified cathode under the same operating conditions. Consequently, the use of such a material as an electrode for the electro-Fenton process was proven to merit further studies and, notably, to be used for the processing of industrial pharmaceutical effluents.RésuméUne nouvelle gamme d’électrodes a été élaborée pour le procédé électro-Fenton par une voie innovante, i.e. par synthèse par voie sol–gel de composites feutre de carbone-hybrides organique-inorganique de structure de type talc (TLH) en employant de l’aminopropyltrimethoxysilane, des chlorures de magnésium et de fer (III) hexahydratés, du feutre de carbone et de l’éthanol. Les composés ont été caractérisés par diffraction des rayons X, analyse thermique, spectrométrie de fluorescence X, spectroscopies infrarouge à transformée de Fourier et de résonance magnétique nucléaire du solide. Il a été montré que l’ordre d’ajout du feutre de carbone dans le milieu de synthèse est l’un des paramètres clés gouvernant l’obtention d’un composite comportant une couche fine et homogène d’hybride à la surface du feutre de carbone et que des composites contenant différentes teneurs en fer peuvent être obtenus. Les performances d’un composite comportant uniquement du fer dans la couche octaédrique de l’hybride ont été testées en tant qu’électrode dans la réaction d’électro-Fenton. Le taux de dégradation du composé organique atteint de 98% après 4 h alors qu’il n’atteint que 70,5%, avec une cathode classique. Ce résultat montre que la réaction de Fenton peut-être réalisée alors que le fer est immobilisé, ce qui montre le potentiel de ces nouvelles électrodes et notamment pour la dégradation de produits pharmaceutiques.
       
  • Recovery of sterols from vegetable oil distillate by enzymatic and
           non-enzymatic processes
    • Abstract: Publication date: Available online 20 February 2019Source: Comptes Rendus ChimieAuthor(s): Guillaume Maniet, Nicolas Jacquet, Aurore Richel Sterols are a group of molecules found in plants and animals, which have a number of valuable applications. The deodorization residue, referred to as “deodistillate”, was previously considered as a waste but its economical value nowadays increased due to the presence of high concentrations of sterols, tocopherols and other secondary metabolites attractive for the cosmetic, pharmaceutical or food industry. Sterols can be extracted from vegetable oil deodistillate through a variety of physical and chemical separation processes or their combination. Recently, the use of lipase enzymes has been demonstrated to separate sterols more selectively in higher yields and in milder conditions. This article reviews these lipase-assisted sterol extractions and their main advantages and drawbacks in economic and environmental terms.
       
  • Improved Cu- and Zn-based catalysts for CO2 hydrogenation to
           methanol
    • Abstract: Publication date: Available online 14 February 2019Source: Comptes Rendus ChimieAuthor(s): Djaouida Allam, Simona Bennici, Lionel Limousy, Smain Hocine In this study the influence of metal dispersion, spinel formation, and surface properties of binary and ternary catalysts (CuOCeO2, ZnOCeO2, CuOZnOCeO2, and CuOZnOAl2O3) was evaluated. The catalysts prepared by polyol method using polyethylene glycol as a solvent have been tested in the CO2 hydrogenation to methanol performed at atmospheric pressure. The catalysts prepared by polyol method presented improved properties in terms of metal oxide dispersion, morphology (i.e. sponge-like shape for the CeO2-containing catalysts), and a large variety of metal and metal oxide species on the surface. Moreover, the CuOZnOCeO2 and CuOZnOAl2O3 catalysts exhibited a higher activity and selectivity in the methanol synthesis by CO2 hydrogenation than those displayed by catalysts prepared by more conventional methods.RésuméDans cette étude, des catalyseurs binaires et ternaires (CuOCeO2, ZnOCeO2, CuOZnOCeO2 et CuOZnOAl2O3) ont été utilisés pour l'hydrogénation du CO2 en méthanol à pression atmosphérique. L'influence de la dispersion des métaux, de la formation de spinelles et des propriétés de surface sur les performances catalytiques a été étudiée. Les catalyseurs, préparés par la méthode polyol en utilisant du poly- éthylène glycol en tant que solvant, présentent des propriétés améliorées en termes de dispersion des oxydes métalliques, de morphologie (forme de type éponge pour les catalyseurs contenant CeO2) et de variétés d'espèces métalliques et d'oxydes métalliques à la surface. De plus, les catalyseurs CuOZnOCeO2 et CuZnOAl2O3 présentent une activité et une sélectivité supérieures à celles de catalyseurs préparés par des procédés plus conventionnels pour la synthèse du méthanol par hydrogénation de CO2.
       
  • Preparation and surface activity study of amino acid surfactants
    • Abstract: Publication date: Available online 28 January 2019Source: Comptes Rendus ChimieAuthor(s): Gang Chen, Jiao Yan, Qiaona Liu, Jie Zhang, Hong Li, Jinling Li, Chengtun Qu, Yongming Zhang Quaternary ammonium cationic surfactants are widely applied in many different fields, such as textile, cosmetic, and petrochemical industries. However, little research has been done on the effects of anion on cationic surfactants. In this study, two new surfactants, cetyltrimethylammonium glycine (CTAG) and octadecyltrimethylammonium glycine (OTAG), were prepared in a simple way using cetyltrimethylammonium chloride (CTAC), octadecyltrimethylammonium chloride (OTAC), and glycine. Then the surface activities were evaluated and compared with the two raw materials. The surface activity of CTAG and OTAG, including surface tension, foaming ability, and emulsification, is better than that of CTAC and OTAC in each case. With the glycine, the corrosion inhibition efficiencies of CTAG and OTAG are 91.12% and 97.89%, respectively, which are more effective than that of CTAC and OTAC. The superior performance of the two surfactants will be very helpful for developing an effective solution in the future.
       
  • Elaboration of alumina-based materials by solution combustion synthesis: A
           review
    • Abstract: Publication date: Available online 28 January 2019Source: Comptes Rendus ChimieAuthor(s): Kawthar Frikha, Lionel Limousy, Jamel Bouaziz, Simona Bennici, Kamel Chaari, Mejdi Jeguirim Alumina (Al2O3) is by far the most commonly used material in industry. It is applied in microelectronics, refractory, catalytic processing, coatings, energy storage, environment protection, and in a wide variety of other industrial applications. In the past decades, various methods have been adopted to synthesize alumina with different properties. Among these methods, solution combustion is considered as an efficient and economic synthesis route, because of its simplicity, low energy consumption, short processing time, and low processing cost. Recent innovations in the combustion and processing parameters have allowed applying this method for the development of a wide range of alumina-based materials. In this review, an overview of the synthesis of alumina and related materials by solution combustion method was provided, relying on the research works reported in the literature since 1988.
       
  • Modified bentonite for anionic dye removal from aqueous solutions.
           Adsorbent regeneration by the photo-Fenton process
    • Abstract: Publication date: Available online 17 January 2019Source: Comptes Rendus ChimieAuthor(s): Selma Khelifi, Fadhila Ayari This study aims to present an effective solution for pollutant treatment after adsorption onto modified bentonite. Modified bentonite has been taken as a medium to divide the treatment process of Congo red (CR) dye by a photo-Fenton process into two different processes (separation of CR from wastewater by adsorption and degradation of CR on the surface of the adsorbent by the photo-Fenton process). The adsorbent was characterized by scanning electronic microscopy, zeta potential, and diffuse reflectance spectroscopy techniques. Batch adsorption experiments were carried out to study the effect of the contact time on the adsorption properties of the dye. Kinetics study and isotherm analysis were conducted. The photo-Fenton regeneration of the adsorbent was investigated under different experimental conditions. The results show the success of the regeneration and the total mineralization of the dye.
       
  • Elaboration and characterization of a low-cost porous ceramic support from
           natural Tunisian bentonite clay
    • Abstract: Publication date: Available online 14 January 2019Source: Comptes Rendus ChimieAuthor(s): Rania Chihi, Issam Blidi, Malika Trabelsi-Ayadi, Fadhila Ayari Ceramic supports from bentonite have become a hot research topic because of their low cost and abundance in many countries. This article describes the development and the characterization of a microfiltration support elaborated using an extrusion method followed by sintering at different temperatures (950, 1000, and 1100 °C). X-ray fluorescence, X-ray diffraction, Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, and differential thermal analysis were used for the characterization of the raw material. The resulting support was characterized by scanning electron microscopy, mechanical and chemical resistance, and water permeability. Each tube was 150 mm in length, with an external diameter of 8 mm and an internal diameter of 5 mm.
       
  • Hectorite and bentonite effect on water-based polymer coating rheology
    • Abstract: Publication date: Available online 9 January 2019Source: Comptes Rendus ChimieAuthor(s): Zane Grigale-Sorocina, Ingmars Birks Increased interest in aesthetic, natural nail coatings has encouraged more in-depth studies, and particularly of ultraviolet curable coatings, their formation, processing, characteristics, and removal. This study investigated the impact of various thixotropic agents (organically modified hectorite and bentonite clays) on water-based oligomer system rheology. Ingredients were evaluated to determine their influence on unreacted composite characteristics (viscosity and pigment suspension stability) and reacted film characteristics (modulus of elasticity, elongation at break, and film adhesion force). It is concluded that clay-based thixotropic agents are suitable for use as a suspension agent in nail polish formulations and, depending on the concentration, can decrease the risk of pigment sedimentation and syneresis.
       
  • Platinum nanoparticles–decorated graphene-modified glassy carbon
           electrode toward the electrochemical determination of ascorbic acid,
           dopamine, and paracetamol
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Manne Anupam Kumar, Vedagiri Lakshminarayanan, Sai Sathish Ramamurthy In the present study, we report the synthesis and characterization of platinum nanoparticles decorated graphene (GPtNPs) nanocomposite toward the electrochemical determination of ascorbic acid (AA), dopamine (DA), and paracetamol (PCT). GPtNPs demonstrated synergistic catalytic activity with enhanced currents in all of the measurements when compared with graphene-modified glassy carbon electrode (G-GCE) and bare GCE. The nanocomposite exhibited low overpotential for AA oxidation and good peak-to-peak separation of 218.0, 218.0, and 436.0 mV for AA–DA, DA–PCT, and AA–PCT, respectively. Cyclic voltammetry (CV) and chronoamperometry (CA) determination of AA, DA, and PCT showed wide linearity ranges. CV determination of AA exhibited linearity range from 300 μM to 20.89 mM and from 22.02 to 39.87 mM. DA determination using CV exhibited linearity range from 5 to 104 μM and from 114 to 684 μM, whereas CA determination of PCT showed a linearity range from 20 μM to 6.43 mM. Differential pulse voltammetry determinations of AA, DA, and PCT exhibited low detection limits of 300, 5, and 5 μM, respectively.
       
  • Synthesis of recoverable palladium composite as an efficient catalyst for
           the reduction of nitroarene compounds and Suzuki cross-coupling reactions
           using sepiolite clay and magnetic nanoparticles (Fe3O4@sepiolite-Pd2+)
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Ehsan Ghonchepour, Mohammad Reza Islami, Behjat Bananezhad, Hamid Mostafavi, Ahmad Momeni Tikdari Clays are nontoxic, inexpensive, abundant, and have great potential as catalytic carriers because of their special structure, surface, and suitability for supporting transition metals. In this study, sepiolite was used as a ligand for the heterogenization of palladium chloride on Fe3O4 nanoparticle surface as a novel, high temperature stable, and recoverable green catalyst (Fe3O4@sepiolite-Pd2+). The catalytic activity of this system was tested in the reduction of nitroarene compounds and the Suzuki cross-coupling reaction. The catalyst structure was characterized using spectroscopic data and magnetic and thermal techniques such as Fourier transform infrared, scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction, vibrating sample magnetometer (VSM), and thermogravimetric analysis.
       
  • Development and physicochemical characterization of
           doxorubicin-encapsulated hydroxyapatite–polyvinyl alcohol nanocomposite
           for repair of osteosarcoma-affected bone tissues
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Saikat Ghosh, Rathnakaram Siva Kumar Raju, Nilanjana Ghosh, Koel Chaudhury, Sampad Ghosh, Indranil Banerjee, Nabakumar Pramanik Nowadays locoregional therapy for cancer treatment can be associated with nanocomposite drug delivery systems. Coated nanoparticles have versatile applications for delivering chemotherapeutic drugs to the targeted part of the body. In this study, a ceramic carrier like nanosized hydroxyapatite (HAp) was synthesized by the in situ precipitation method followed by coating with anticancer drug like doxorubicin (DOX) and polyvinyl alcohol (PVA) polymer. The physicochemical characterization of the prepared polymer-coated drug ceramic nanocomposite (DOX-HAp-PVA) was carried out using Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron spectroscopy, and particle size distribution. Furthermore, the biocompatibility and the anticancer activity of the nanocomposite were explored by MTT assay study. Successfully synthesized DOX-HAp-PVA nanocomposite exhibited a remarkable cytotoxicity toward osteosarcoma cells (MG 63), which may be potentially used as an anticancer agent against osteosarcoma.Graphical abstractImage 1
       
  • Internal path investigation of the acting electrons during the
           photocatalysis of panchromatic ruthenium dyes in dye-sensitized solar
           cells
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Nouha Kouki, Salma Trabelsi, Mohamadou Seydou, François Maurel, Bahoueddine Tangour A series of heteroleptic Ru(II) complexes were theoretically investigated using time-dependent density functional theory. These dyes, including K8 and N3, are based on a common motif formed by Ru center, NCS, and polypyridyl ligands, but differ only by the nature of the added group in para position of each pyridyl. The presence of these ligands will enable the evaluation of the electronic effects ±I and ±M. This work focuses on the localization of the part, among the metal, the NCS, the polypyridyl ligands, and the added group R, which is most actively involved in the photocatalysis process. We dealt with both ground and excited states as well as the electronic transitions between them. To illustrate the effect of each functional group R on its photophysical properties, the geometries of five dyes were optimized in the molecular and univalent cationic states. All molecules are asymmetrical in shape with a distorted octahedral coordination of the RuN6 core. Atomic charge and spin density distributions show that a charge transfer process occurs from the NCS/Ru to polypyridyl ligand. Analysis of the electronic absorption spectra reveals that the band with the highest wavelength value is assigned to metal-to-ligand charge transfer transition. On the contrary, two other bands are assigned to multitransitions Ru/NCS to polypyridyl–π*. These attributions have been confirmed by the localization of all atoms intervening in them. We also introduced an adapted way to estimate the ionization probability values in each atomic center in the ground and first excited states. Phenomenal properties such as mobility, redox potential, electronic spectrum, ionization potential, and optical gap of the most efficient dye, which is the N3, fit well with experimental values.
       
  • Sensitive electrochemical detection of methyl parathion in the presence of
           para-nitrophenol on a glassy carbon electrode modified by a functionalized
           NiAl-layered double hydroxide
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Aude P.W. Kameni, Hervé L. Tcheumi, Ignas K. Tonle, Emmanuel Ngameni An inorganic–organic composite material was prepared by the insertion of bis(ethylhexyl)hydrogen phosphate (BEHP) within the interlayer space of a nickel-aluminum–layered double hydroxide (NiAl LDH). X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared were used to characterize the pristine and modified LDH (NiAl–BEHP), which together confirm the intercalation of BEHP in the mineral structure. Cyclic voltammetry using [Fe(CN)6]3− as an anionic redox probe demonstrated a significant decrease in the anion exchange capacity of NiAl upon modification. Used as electrode modifier for methyl parathion (MP) detection, a remarkable increase in MP signal on NiAlBEHP–modified glassy carbon electrode (GCE/NiAl–BEHP) was observed, because of the high hydrophobicity character of the modified LDH. The signal assigned to the electroactivity of the nitro group being less stable than that of the reduction of the nitroso group, the use of both functions was explored for the calibration experiments. Sensitivities of 0.79 μA μM−1 and 0.14 μA μM−1 were obtained, with detection limits of 2.28 × 10−8 and 12.4 × 10−8 mol L−1 for nitro and nitroso groups, respectively. However, the linearity range was more important for the nitroso group (0.5–12 μM) as compared to the nitro group (0.5–3.5 μM). Moreover, the signal of the nitroso group showed poor interference with some chemical species likely to be encountered in the presence of MP. The GCE/NiAl-BEHP–modified electrode was particularly effective for the differentiation of 4-nitrophenol (4-NP) from MP. Interestingly, the decrease in the sensor sensitivity was negligible (0.13 μA μM−1) when the calibration curve of MP was plotted in the presence of 1 μM of 4-NP. The poor efficiency of the sensor to quantify 4-NP was probably because of the high organophilic character of the electrode material. The developed method was successfully applied to quantify MP in spring water.RésuméUn matériau composite inorgano–organique a été préparé par insertion d'hydrogénophosphate de bis(éthylhexyl) (BEHP) dans l'espace intercouche d'un hydroxyde double lamellaire (HDL) nickel–aluminum (NiAl). La diffraction de rayons X, l'analyse thermique et la spectroscopie infrarouge ont été utilisées pour caractériser l’HDL de départ et celui issue de l'intercalation (NiAl–BEHP), techniques qui toutes ont confirmé le processus d'insertion de la molécule organique dans la structure minérale. La voltammétrie cyclique utilisant la sonde électrochimique anionique [Fe(CN)6]3− a montré une diminution significative de la capacité d'échange anionique de l’HDL lors de la modification. Utilisé comme modifiant d'électrode pour la détection du méthyl parathion (MP), une augmentation remarquable du signal MP sur l'électrode de carbone vitreux (CV) modifiée par NiAl−BEHP (CV/NiAl–BEHP) a été observée en raison du caractère hautement hydrophobe dudit matériau. Le signal attribué à l'électroactivité du groupe nitro étant moins stable que celui de la réduction du groupe nitroso, l'utilisation des deux fonctions a été explorée pour les expériences de calibration. Des sensibilités de 0,79 μA μM−1 et 0,14 μA μM−1 ont été obtenues, avec des limites de détection de 2,28 × 10−8 et 12,4 × 10−8 mol L−1, respectivement pour les groupements nitro et nitroso. Cependant, la gamme de linéarité la plus importante a été celle présentée par le groupement nitroso (0,5 μM à 12 μM) par rapport au groupe nitro (0,5 μM à 3,5 μM). De plus, le signal du groupe nitroso a montré une faible interférence avec certaines espèces chimiques susceptibles d'interférer avec le MP. L'électrode modifiée CV/NiAl−BEHP a été particulièrement sélective vis-à-vis des deux analytes étudiés. Ce qui est plus intéressant, la diminution de la sensibilité du capteur a été négligeable (0,13 μA μM−1) lorsque la courbe d'étalonnage du MP a été tracée en présence de 1 μM de 4-NP. Cette observation peut être attribuée au caractère organophile élevé du matériau NiAl−BEHP déposé sur l’électrode de carbone vitreux. La méthode développée a été appliquée avec succès pour quantifier le MP dans une eau de source.
       
  • Effect of phosphorus on the performance of IM-5 for the alkylation of
           toluene with methanol into p-xylene
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Cui Wang, Yaquan Wang, Hengbao Chen, Xiao Wang, Hongyao Li, Chao Sun, Liying Sun, Chunyang Fan, Xu Zhang IM-5 zeolite was modified with different amounts of phosphorus species. The effect of the introduction of phosphorus into IM-5 zeolite (P-IM-5) was evaluated on the alkylation of toluene with methanol. The samples were characterized by X-ray diffraction, scanning electron microscopy, N2 physical adsorption, 31P magic angle spinning nuclear magnetic resonance, inductively coupled plasma optical emission spectroscopy, temperature-programmed desorption of ammonia, Fourier transform infrared spectra of pyridine, 2,6-di-tert-butyl-pyridine and 2,6-lutidine adsorption, and thermogravimetric analysis after reaction. The results showed that the zeolite structure was not changed, but the total amount of acid sites decreased with increasing phosphorus loading. The phosphorus-modified IM-5 samples exhibited much higher stability on the alkylation of toluene with methanol than the parent zeolite and the optimal phosphorus amount added was 0.5 wt %. The excellent catalytic performance could be ascribed to the low ratio of B/L acid sites upon phosphorus modification, which suppressed coke formation.
       
  • Synthesis, crystal structure, and density functional theory study of a
           zinc(II) complex containing terpyridine and pyridine-2,6-dicarboxylic acid
           ligands: Analysis of the interactions with amoxicillin
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Adedibu C. Tella, Joshua A. Obaleye, Margaret D. Olawale, Jean Marie Vianney Ngororabanga, Adeniyi S. Ogunlaja, Susan A. Bourne An octahedral zinc(II) complex of 2,2′:6′,2″-terpyridine (Tpy) and pyridine-2,6-dicarboxylate (Pydc), [Zn(II)(Tpy)(Pydc)·4H2O] was synthesized and its structure was determined by a single-crystal X-ray diffraction. The ligand pyridine-2,6-dicarboxylate coordinated to the zinc(II) ion via two pairs of carboxylate oxygens and one nitrogen atom, whereas 2,2′:6′,2″-terpyridine also contributed three coordination bonds through its nitrogen atoms. [Zn(II)(Tpy)(Pydc)·4H2O] showed luminescence properties between 412 and 435 nm in DMSO. The solid-state octahedral geometry of [Zn(II)(Tpy)(Pydc)·4H2O] was also preserved in solution as confirmed by the observed UV λex = 346. Experimental and theoretical studies indicated that [Zn(II)(Tpy)(Pydc)·4H2O] interacted with amoxicillin. Density functional theory calculations at B3LYP/LanL2dz level of theory suggested that [Zn(II)(Tpy)(pydc)·4H2O] dimer interacts with (2S,5R,6R)-6-{[(2R)-2-amino-2-(4-hydroxyphenyl)-acetyl]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-24-carboxylic acid (amoxicillin) via highest occupied molecular orbital and lowest unoccupied molecular orbital, π–π interaction, hydrogen bond interaction, and van der Waals forces, thus influencing [Zn(II)(Tpy)(Pydc)·4H2O] properties.
       
  • Editorial
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Pierre Braunstein
       
  • Sommaire / Contents
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s):
       
  • Editorial Board - French
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s):
       
  • Fe3O4 anodes for lithium batteries: Production techniques and general
           applications
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Qichao Wu, Rongli Jiang, Lixue Mu, Senyuan Xu Iron oxides, such as Fe3O4, are putative anode materials for rechargeable lithium-ion batteries (LIBs). LIBs are extensively used as power sources for electronics. They typically consist of cells, with each cell built out of a lithium cathode and a graphite anode. However, graphite anodes suffer from the disadvantages of significant density, large volume, low energy density, and inferior safety levels. Iron oxides seem to be a promising substitute to the currently used graphite anodes due to their high capacity, extensive availability, good stability, and environmental tolerance. Nevertheless, several hurdles prevent their market expansion, such as inferior electronic/ionic conductivity, large volume changes, poor cycling performance, and low coulombic efficiency. Using Fe3O4 seems to be one alternative to address these challenges. This review will cover the current state of development of iron oxide electrodes with respect to design, production techniques, and general applications.
       
  • Editorial Board - English
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s):
       
  • Novel 4-azaandrostenes as prostate cancer cell growth inhibitors:
           Synthesis, antiproliferative effects, and molecular docking studies
    • Abstract: Publication date: January 2019Source: Comptes Rendus Chimie, Volume 22, Issue 1Author(s): Vanessa Brito, Adriana O. Santos, Paulo Almeida, Samuel Silvestre In this study, synthesis, structural characterization, molecular docking studies, and antiproliferative effects in four different cell lines of several novel 16-arylidene-4-azaandrost-5-ene compounds are reported. These compounds were prepared by oxidative cleavage of the enone system of androstenedione followed by an azacyclization reaction and an aldol condensation with various aldehydes at C16. In the androgen-dependent LNCaP cells, the most relevant antiproliferative effects were observed with the 16-phenyl, 16-p-tolyl, and 16-p-nitrophenyl derivatives. Compound 16E-[(4-methylphenyl)methylidene]-4-azaandrost-5-ene-3,17-dione was the most potent in these cells (IC50 = 28.28 μM), having lower antiproliferative effects in the androgen-independent PC-3 cells (IC50 = 45.31 μM). In addition, an interesting selectivity toward cancer cell lines was found for all compounds because a generally low cytotoxicity was detected in healthy human fibroblasts. Furthermore, the 16-p-tolylazaandrostene steroid induced a reduction of viability in LNCaP cells similar to that observed with finasteride, a clinically used 5α-reductase inhibitor. Moreover, molecular docking studies predicted that these 4-azaandrostene derivatives can interact with 5β-reductase, which has a high level of similarity to 5α-reductase enzyme, and with other common targets of steroidal drugs, particularly the enzyme 17α-hydroxylase/17,20-lyase.
       
  • Production of geopolymer binders using clay minerals and industrial wastes
    • Abstract: Publication date: Available online 28 December 2018Source: Comptes Rendus ChimieAuthor(s): Noureddine Hamdi, Imen Ben Messaoud, Ezzeddine Srasra The objective of this study was to establish the most suitable mixtures of Tunisian illito-kaolinitic clay and industrial wastes (phosphogypsum [PG] and waste brick) to produce geopolymer binders. The raw clay sample was heated at 850 °C and characterized by chemical and thermal analyses, X-ray diffraction, and infrared spectroscopy. Four mixtures with different ratios (4%, 8%, 12%, and 16%) of PG as a partial replacement for the calcined clay were investigated. The obtained mixture powders were dissolved in a strong alkaline solution (10, 14, and 17 mol (NaOH)/L) and the produced geopolymers were preserved for 28 days and then characterized by determining their compressive strength. Results showed that increasing the percentage of PG up to 8% reveals an enhancement in the mechanical properties. The highest value of 36 MPa was attained for NaOH concentration of 14 M. At this optimal condition, the calcined clay was replaced by the powder of waste red brick and the produced geopolymer binders had almost the same mechanical property.
       
  • Physicochemical characteristics and suitability of curative pastes made of
           Tunisian clay minerals and thermal waters for use in pelotherapy
    • Abstract: Publication date: Available online 15 December 2018Source: Comptes Rendus ChimieAuthor(s): Thouraya Barhoumi, Imene Bekri-Abbes, Ezzeddine Srasra This study presents the physicochemical characteristics of peloids prepared from two Tunisian clays, CZ (clay from the region of Zaghouan) and CS (from the region of Siliana), and two thermal mineral waters. The samples were analyzed by several physicochemical techniques: X-ray diffraction, chemical composition (major and minor elements), grain-size distribution, cation-exchange capacity, plasticity index, and thermal properties (cooling kinetic). The results prove that the two clays are suitable for use in Tunisian spa with differences in their characteristics, especially with regard to their composition, plasticity, grain size distribution, and thermal properties.
       
  • Efficient catalytic performance of tetra-alkyl orthotitanates for the
           oxidative desulfurization of dibenzothiophene at room temperature
    • Abstract: Publication date: Available online 14 December 2018Source: Comptes Rendus ChimieAuthor(s): Xiaolin Li, Hui Qi, Wei Zhou, Wei Xu, Yinyong Sun Desulfurization of fuel oil is of great importance for producing clean energy. In this study, we report that tetra-alkyl orthotitanates exhibited efficient catalytic performance in the oxidative desulfurization of dibenzothiophene. The sulfur content in model oil (1000 ppmw) could be reduced to less than 10 ppmw within 10 min at room temperature and ambient pressure. In addition, the formed sulfones can be easily separated from the oil phase without extraction process. This work will provide a basis for the design of novel oxidative desulfurization catalysts with high desulfurization efficiency.
       
  • Synthesis and cytotoxicity of two novel alcohols based on a
           benzo[c]phenanthrene moiety
    • Abstract: Publication date: Available online 5 December 2018Source: Comptes Rendus ChimieAuthor(s): Habiba Guédouar, Béchir Ben Hassine, Faouzi Aloui Synthetically, 1-(benzo[c]phenanthren-2-yl)ethanol and 1-(benzo[c]phenanthren-2-yl)-3-phenylpropane-1,3-diol were successfully obtained from 2-acetylbenzo[c]phenanthrene and methyl benzo[c]phenanthrene-2-carboxylate, respectively, and fully characterized. The desired compounds were purified by silica gel column chromatography, and their structures were characterized by melting points, 1H NMR, 13C NMR, and mass spectroscopy. Next, the in vitro cytotoxicity of the new polyaromatic alcohols was evaluated against two human carcinoma cell lines (Hep-2 and Caco-2) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method. Consequently, the 1,3-diol derivative displayed the highest cytotoxicity against both cell lines (IC50 = 0.7 and 0.6 μg/mL). This allowed us to infer that the effect of intramolecular hydrogen bond seems to be important for the cytotoxic activity.Graphical abstractImage 1
       
  • Molecular electronics: Scanning tunneling microscopy and single-molecule
           devices
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Amandine Bellec, Jérôme Lagoute, Vincent Repain Among switchable molecules, spin-crossover molecules are particularly appealing for molecular electronics as their change in spin state is associated with a large change in conductance and can also be used for molecular spintronic devices. In this article, we review the techniques that allow one to measure the electronic transport through single spin-crossover molecules. We particularly emphasize recent experiments using scanning tunneling microscopy and spectroscopy, where the spin state can be controlled by electric field, electric current or light.RésuméLes molécules à transition de spin sont, parmi la vaste classe de molécules qui peuvent transiter entre deux états, particulièrement intéressantes pour l’électronique moléculaire. En effet, la modification de leur état de spin est associée à un changement important de leur conductance électronique et pourrait également être utilisée dans des dispositifs d’électronique de spin moléculaire. Dans cet article, nous proposons un état de l'art des différentes techniques qui permettent de mesurer le transport électronique à travers des molécules uniques à transition de spin. Nous détaillons plus particulièrement des expériences récentes utilisant la microscopie et la spectroscopie à effet tunnel, où l’état de spin d'une molécule unique peut être contrôlé par le champ électrique, le courant électrique ou la lumière.
       
  • Surfaces, thin films and patterning of spin crossover compounds
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Talal Mallah, Massimiliano Cavallini Spin crossover compounds are multifunctional switching materials that change their spin state and many other physical properties, such as colour, magnetic susceptibility, electric conductivity, dielectric constant and mechanical properties, upon external stimuli. Spin crossover materials have been proposed for a variety of technological applications that require the elaboration of highly controlled thin films and patterns. Here, we present a brief overview of the most diffused approaches for thin film growth and patterning, showing both conventional and unconventional approaches and the most recent advancement in their applications, highlighting the most promising cases and the most critical problems.RésuméLes composés à transition de spin sont des matériaux moléculaires multifonctionnels commutables. Leur état de spin ainsi que d'autres propriétés physiques comme la couleur, la conductivité électrique, la constante diélectrique, les propriétés mécaniques peuvent être modulés et contrôlés par une perturbation extérieure. Ces matériaux ont un potentiel important dans des applications comme le stockage de l'information, la thermométrie, les systèmes micro- et nano-électromécaniques, etc., qui nécessitent un contrôle fin de leur mise en forme en couches minces continues et/ou structurées. Nous présentons ici une revue brève sur les approches conduisant à la croissance de films minces et à leur structuration pour différentes applications, montrant les cas les plus prometteurs et analysant les problèmes les plus critiques.
       
  • Spin-crossover nanoparticles and nanocomposite materials
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Lionel Salmon, Laure Catala This contribution reports on the state of the art of the elaboration and the application of nanoparticles (NPs) and nanohybrid/nanocomposite materials based on spin-crossover (SCO) complexes. The first part of this review concerns the syntheses and the characterizations of the physical properties of SCO NPs. All of the methods including homogeneous and heterogeneous media syntheses developed for the elaboration of such NPs and the associated methods used for their morphological characterization are presented. A particular attention is paid on the effects of the size reduction and the influence of the environment on the SCO properties and to specific and recent remarkable advanced physical measurements realized on a batch of NPs or on an isolated object. The second part presents the elaboration of various nanocomposite or nanohybrid materials for which SCO NPs have been associated with magnetic entities, noble metals, different fluorescent dyes, and different active polymers with the objectives to go toward specific applications based on synergistic effects between the two components.RésuméCette contribution rend compte de l'état de l'art sur l'élaboration et la mise en application de nanoparticules et de matériaux nanohybrides/nanocomposites à base de complexes à transition de spin. La première partie de cette revue concerne la synthèse et la caractérisation des propriétés physiques de nanoparticules à transition de spin. Toutes les méthodes, y compris les synthèses en milieux homogène et hétérogène développées pour l'élaboration de telles nanoparticules et les méthodes utilisées pour leurs caractérisations morphologiques, sont présentées. Une attention particulière est portée aux effets de la réduction de taille et de l'influence de l'environnement sur les propriétés de transition de spin et sur des mesures physiques récentes remarquables réalisées sur un lot de nanoparticules ou sur un objet unique. La deuxième partie présente l'élaboration de divers matériaux nanocomposites ou nanohybrides au sein desquels des nanoparticules à transition de spin ont été associées à des entités magnétiques, des métaux nobles, divers fluorophores et différents polymères actifs dans le but d'aller vers des applications spécifiques basées sur des effets synergétiques entre les deux composants.
       
  • Polynuclear Fe(II) complexes: Di/trinuclear molecules and coordination
           networks
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Jose Ramón Galán Mascarós, Guillem Aromí, Mohanad Darawsheh We review here the recent progress made in the synthesis of spin crossover (SCO) Fe(II) coordination complexes with two or three metal atoms, as well as coordination polymers, with the main focus on that in the last five years. We discuss these as well as their magnetic properties to derive magnetostructural correlations. This manuscript is organized through the ligand types that serve to produce the various coordination systems presented. The ligand structure and essential SCO parameters of the complexes are gathered in comprehensive figures and tables. This review illustrates the richness and key parameters of coordination chemistry to develop multiple architectures with the desired properties involving this fascinating phenomenon.
       
  • Mononuclear ferrous and ferric complexes
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Marie-Laure Boillot, Birgit Weber This contribution reports on the recent developments concerning spin-crossover Fe(II) and Fe(III) complexes of mononuclear nature. In the first section, the description of chemical environments encountered in this iron coordination chemistry is briefly introduced. The background related to the switchability and cooperativity of the molecular materials is followed by a summary of the very first developments directed toward applications. Presently, these molecule-based systems are broadly used for the design, the elaboration of multifunctional materials, or for more fundamental investigations of scaling effects. It will be presented with a focus on usual and unusual iron coordinances, the design of systems with multiple functionalities, and also the few coordinatively unsaturated examples that react to chemical stimuli with a spin change of the iron ion.
       
  • Elastic models, lattice dynamics and finite size effects in molecular spin
           crossover systems
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Cristian Enachescu, William Nicolazzi The experimental studies of spin-crossover compounds switched in the last decade from bulk measurements and macroscopic observations to the nanoscale and microscopic approaches. In this context, new and sometimes unexpected behaviours have been documented, which could be partially described only by the classical phenomenological models developed in the last period of the last century. In this context, the development of more complex models, able to reproduce the nucleation and domain propagation within the material, has proved to be not a whim of some theoreticians but a necessity, which facilitated the full understanding of observed phenomena and even made premises for further experiments. Here, we present and analyse various elastic models identifying their common points and differences and discuss how they can be used for the study of microscopic phenomena as the cluster formation, stability and propagation or for the study of finite size effects in spin-crossover nanoparticles, with open boundary conditions or embedded in various matrices.
       
  • Microscopic models of spin crossover
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Ján Pavlik, Jorge Linares The 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 research on SCO and a simple applicability in quantitative interpretation of experiments.
       
  • Spectroscopic techniques to characterize the spin state: Vibrational,
           optical, Mössbauer, NMR, and X-ray spectroscopy
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Juliusz A. Wolny, Volker Schünemann, Zoltán Németh, György Vankó Basic principles and recent work using probes including Mössbauer, optical, X-ray, and vibrational spectroscopies to follow the transitions in spin crossover complexes are reviewed. X-ray spectroscopy, being a relatively lesser-known probe, is discussed in more detail. X-ray spectroscopic methods have been used in the spin crossover field mostly to elucidate surface phenomena, ultrafast dynamics, and high pressure effects, but recent technical developments provide perspectives for a more widespread use of these powerful techniques in home laboratories.
       
  • Structural analysis of spin-crossover materials: From molecules to
           materials
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Eric Collet, Philippe Guionneau In molecular spin-crossover materials, the spin-state switching is strongly coupled with changes in the structural degrees of freedom, which play a central role in the alteration of functions and mechanisms of transformation from the molecular scale (bond lengths) to the material scale (volume). This article reviews various techniques currently used, ranging from microscopy to diffraction, to study the structural aspects related to spin crossover at different physical scales. Some of the most important recent advances concern the resolution of complex crystal structures, the determination of microstructures, the study of phase coexistence, temporal studies ranging from second to femtosecond, and the description of multistep transition involving intricate ordering of molecules in different electronic states.RésuméDans les matériaux moléculaires à conversion de spin, la modification de l'état de spin est fortement couplée aux changements des degrés de liberté structuraux, qui jouent un rôle central dans l'altération des propriétés et dans les mécanismes de transformation, de l'échelle de la molécule (longueur de liaison) à l'échelle du matériau (volume). Cet article passe en revue différentes techniques utilisées actuellement, allant de la microscopie à la diffraction, pour étudier les aspects structuraux fondamentaux liés au changement d'état de spin aux différentes échelles physiques. Les avancées récentes les plus marquantes concernent la résolution de structures cristallines complexes, la détermination des microstructures, l'étude de la coexistence de phases, les études temporelles allant de la seconde à la femtoseconde et la description de transition multi-étapes impliquant des mises en ordre complexes de molécules dans différents états électroniques.
       
  • Macroscopic methods: Magnetic, optical, and calorimetric techniques
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): José Sanchez Costa The recent effervescent impetus in the spin transition research field is associated with the prodigious multidisciplinary effort that is carried out by different research groups all over the world. Indeed, more and more groups are working in this exciting research field. Nevertheless, this renewed interest also reflects the evolution of the characterization techniques that have been used since the earliest studies of these molecular-based switchable materials. Indeed, we have passed from traditional characterization methods such as UV–vis and Mössbauer spectroscopy or torque magnetometers to the most advanced techniques that are even capable to monitor a spin transition in a single molecule (e.g., X-ray diffraction, X-ray photoelectron spectroscopy, scanning tunneling microscopy, etc.). In this study, we will focus on the basis and the evolution of three critical macroscopic tools, i.e. the optical, magnetic, and calorimetric characterization methods.
       
  • Pressure effect investigations on spin-crossover coordination compounds
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Ana B. Gaspar, Gábor Molnár, Aurelian Rotaru, Helena J. Shepherd The piezochromic properties of spin-crossover complexes have been recognized for a long time, with increasing pressure favouring the low spin state due to its smaller volume and therefore shifting the spin equilibrium towards higher temperatures and accelerating the relaxation at a given temperature. However, the interpretation and quantification of pressure-induced changes have been several times compromised by the relatively poor and incomplete spectral and structural information provided by the detection methods or due to the experimental difficulties related to the need for hydrostatic conditions at low temperatures. The present review is therefore primarily focused on these experimental aspects of high-pressure spin crossover research providing an overview of methods of pressure generation and associated detection methods as well as on selected recent results.RésuméLes propriétés piézo-chromiques de complexes à transition de spin ont été identifiées depuis longtemps. Du point de vue théorique, l'application d'une pression favorise l'état bas spin, de plus petit volume. Ainsi, les températures de transition augmentent et les cinétiques de relaxation s'accélèrent sous pression. Toutefois, l'interprétation et la quantification des modifications induites par la pression restent un challenge en raison de la difficulté d'obtenir des données structurales et spectrales fiables dans des conditions de pression hydrostatique. Ceci est d'autant plus vrai lorsque les hautes pressions et les basses températures doivent être combinées. Ainsi, l'objectif principal du présent article est une mise au point sur les techniques utilisées pour l’étude des composés à transition de spin sous pression – illustrées par une sélection de résultats récents.
       
  • Light-induced spin crossover—Solution and solid-state processes
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Guillaume Chastanet, Maciej Lorenc, Roman Bertoni, Cédric Desplanches This article overviews the different light-induced spin-crossover processes that are induced using ligand photoreaction, photothermal effects, or optical absorption of the center metallic ion. A particular attention is drawn on the light-induced excited spin-state trapping effect, the most studied phenomenon, by discussing the recent developments in terms of description of the initial photoswitching process and the mechanisms developing at different time scales, as well as the lifetime of the photoinduced state.RésuméCette revue présente les différentes approches suivies pour induire une conversion de spin par la lumière en utilisant des ligands photosensibles, des effets photo-thermiques ou les propriétés optiques du centre métallique. Une attention particulière est portée à l'effet LIESST (light-induced excited spin-state trapping), le phénomène le plus étudié, en présentant les développements récents en termes de description du processus de photocommutation aux différentes échelles de temps et de durée de vie de l’état photo-induit.
       
  • Thermodynamical aspects of the spin crossover phenomenon
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): William Nicolazzi, Azzedine Bousseksou Fundamental aspects of spin crossover (SCO) mechanisms are reviewed through considerations of ligand/crystal field theory, thermodynamics, and modeling of the thermoinduced spin transition in the solid state based on macroscopic–mesoscopic approaches . In particular, we highlight success of thermodynamic models in the simulation of first-order spin transitions with hysteretic behaviors (bistability) and multistep conversions. Bistability properties originate from elastic interactions, the so-called cooperativity between SCO molecules in the crystal packing. Although physical and chemical properties and thermodynamical quantities of noninteracting SCO compounds can be readily injected in macroscopic models, taking cooperativity into account remains problematic. The relationship between phenomenological numerical parameters and experimentally accessible quantities can only be most of the time indirectly established. Recent extensions of these thermodynamical models to grasp SCO properties at the nanoscale and combinations with ab initio numerical methods show that macroscopic models still constitute useful theoretical tools to investigate SCO phenomena. The necessity to further probe the thermomechanical properties of SCO materials is also emphasized.RésuméDans cette revue, les aspects fondamentaux des mécanismes de conversion de spin sont abordés au travers de divers formalismes théoriques bien connus en physique et chimie de la matière condensée, tels que la théorie du champ de ligand/cristallin, la thermodynamique des mélanges binaires et les modèles macroscopiques–mesoscopiques associés pour simuler la transition de spin thermo-induite. En particulier, nous rapportons les différents succès des modèles thermodynamiques dans la simulation de transitions de spin du premier ordre présentant des phénomènes d'hystérésis (bistabilité) et des transitions en plusieurs étapes. L'existence du phénomène de bistabilité est directement reliée aux mécanismes d'interaction élastique entre les molécules à conversion de spin appelés « cooperativité ». Alors que les propriétés physiques et chimiques ainsi que les quantités thermodynamiques des composés à conversion de spin isolés peuvent être facilement injectées dans des modèles macroscopiques, la prise en compte de la coopérativité reste compliquée à réaliser. La relation entre les paramètres numériques phénoménologiques et les quantités accessibles expérimentalement ne peut être, la plupart du temps, établie que de manière indirecte. Des extensions récentes de ces modèles thermodynamiques destinées à mieux comprendre les propriétés de la conversion de spin à l'échelle nanométrique combinées à des méthodes numériques ab initio montrent que les modèles thermodynamiques constituent toujours un outil théorique utile pour étudier la transition de spin. La nécessité d’étudier davantage les propriétés statiques et de transport thermomécaniques de cette classe de matériaux bistables est également soulignée.
       
  • Preface and introduction
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Jacqueline Zarembowitch, François Varret, Andreas Hauser, José-Antonio Real, Kamel Boukheddaden
       
  • In memoriam of Professor John J. McGarvey
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s): Azzedine Bousseksou, Gabor Molnár
       
  • Sommaire / Contents
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s):
       
  • Editorial Board - French
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s):
       
  • Editorial Board - English
    • Abstract: Publication date: December 2018Source: Comptes Rendus Chimie, Volume 21, Issue 12Author(s):
       
  • Mass transfer modelling in clay-based material: Estimation of apparent
           diffusivity of a molecule of interest
    • Abstract: Publication date: Available online 1 December 2018Source: Comptes Rendus ChimieAuthor(s): Patrick Dutournié, Marion Bruneau, Jocelyne Brendlé, Lionel Limousy, Sylvain Pluchon This work is devoted to study the controlled release of a molecule of interest in an external medium. The molecule is previously adsorbed in an organic porous material, encapsulated in a thin clay layer. The experimental release kinetics is investigated for the organic material and the clay-based material in two external media: pure water and saline solution. A numerical modelling was developed to understand the different phenomena that act on the molecule transfer. The results show that the hydration of the clay-based material reduces the release kinetics. Moreover, it was observed that the molecules are released faster in pure water than in the saline solution. This phenomenon is explained by the osmotic pressure difference on both sides of the clay layer.ResumeCe travail a pour but d'étudier le relargage contrôlé d'une molécule d'intérêt (tryptophane) dans un milieu. Pour cela, la molécule est adsorbée dans un matériau organique poreux, lui-même encapsulé sous une fine couche de type argile. La cinétique de relargage de la molécule est étudiée pour le matériau poreux seul et encapsulé dans deux milieux externes (eau pure et solution saline). Un modèle de connaissance a été réalisé afin de comprendre les différents phénomènes qui gouvernent le transport de la molécule. Les résultats montrent que l'hydratation du matériau encapsulé joue un rôle important dans la vitesse de relargage du tryptophane. De plus, il a été observé que cet acide aminé diffuse plus vite dans l'eau pure que dans la solution saline, ce qui est expliqué par la présence d'un gradient de pression lié à la différence de concentration en sel de part et d'autre de la fine couche argileuse.
       
  • Removal of anionic dye from textile industries' effluents by using
           Tunisian clays as adsorbents. Ζeta potential and streaming-induced
           potential measurements
    • Abstract: Publication date: Available online 23 November 2018Source: Comptes Rendus ChimieAuthor(s): Nejib Abidi, Joëlle Duplay, Amane Jada, Emna Errais, Malika Ghazi, Khadija Semhi, Malika Trabelsi-Ayadi In the present work, we have investigated the adsorption capacities of natural raw clays originated from Tunisia, such as those from Tabarka (a mixture of kaolinite and illite) and from Fouchana (a mixture of smectite, kaolinite, and illite), a standard kaolinite (KGa-2), and a palygorskite (PFl-1) for the removal of a reactive red dye (RR 120) usually found in textile industry effluents. Thus, batch adsorption experiments were performed and were tuned by varying different parameters such as adsorption contact time, aqueous phase pH, ionic strength, and initial dye concentration. In addition, zeta potential measurements allowed the determination of the electrical charge and of the dye behavior at the clay–water interface. Despite the fact that palygorskite has higher porosity and specific surface values, the amount of dye adsorbed on this clay is low in comparison to that of the other solid samples, regardless of the values of pH and ionic strength of the aqueous phase. On the other hand, a higher amount of adsorbed dye was observed on KGa-2, having the lowest specific surface area value. This sample, in comparison to smectite and fibrous clays, was found to be more efficient in the removal the anionic dye, and thus it can be used as an adsorbent for the treatment of effluents in the textile industry.RésuméDans ce travail, nous avons étudié les capacités d'adsorption des argiles naturelles brutes originaires de Tunisie, telles que celles de Tabarka (mélange de kaolinite et d'illite), de Fouchana (mélange de smectite, kaolinite et illite), une kaolinite standard (KGa-2) et une palygorskite (PFl-1), pour éliminer un colorant rouge réactif (RR 120) présent dans les effluents de l'industrie textile. Ainsi, des expériences d'adsorption en batch ont été réalisées, examinant différents paramètres tels que le temps de contact adsorbant–adsorbat, le pH et la force ionique de la phase aqueuse, la concentration initiale en colorant. Par ailleurs, des mesures du potential zêta et du potentiel d’écoulement induit des différentes dispersions aqueuses en absence et en présence du colorant ont permis de déterminer la charge électrique et le comportement du colorant à l'interface argile–eau. Les résultats montrent que, malgré le fait que la palygorskite présente une porosité et une surface spécifique élevées, la quantité de colorant adsorbée sur cette argile est faible par rapport à celles des autres argiles, quelles que soient les valeurs de pH et de force ionique de la phase aqueuse. Par ailleurs, la quantité de colorant adsorbé la plus élevée a été observée sur la kaolinite (KGa-2), qui s'est avérée être l'adsorbant le plus efficace pour éliminer le colorant anionique et traiter les effluents de l'industrie textile.Graphical abstractImage 1
       
  • Ferromagnetic coupling through the oxalate bridge in heterobimetallic
           Cr(III)–M(II) (M = Mn and Co) assemblies
    • Abstract: Publication date: Available online 23 November 2018Source: Comptes Rendus ChimieAuthor(s): Francisco R. Fortea-Pérez, Julia Vallejo, Jorge Pasán, Catalina Ruiz-Pérez, Joan Cano, Francesc Lloret, Miguel Julve Two novel compounds, {[Cr(pyim)(ox)2]2Mn}n·2nCH3OH (1) and {[Cr(pyim)(ox)2]2Co(H2O)2}·7.5H2O (2) [pyim = 2-(2′-pyridyl)imidazole and H2ox = oxalic acid], were synthesized by using the mononuclear chromium(III) complex PPh4[Cr(pyim)(ox)2]·H2O (PPh4+ = tetraphenylphosphonium) as metalloligand towards the fully solvated manganese(II) (1) and cobalt(II) (2) ions as perchlorate salts. The structure of 1 consists of neutral double chains, with diamond-shaped units sharing the manganese(II) ions with the two other corners being occupied by the chromium(III) ions. The two metal centres in 1 are connected by bis-bidentate oxalate groups, each [CrIII(pyim)(ox)2]− unit being bound to two manganese(II) ions through its two oxalate ligands. Complex 2 is a centrosymmetric trinuclear compound where two outer [CrIII(pyim)(ox)2]− units act as bidentate ligands through one of their two oxalate groups towards the inner trans-diaquacobalt(II) entity. The values of the chromium(III)–manganese(II) (1) and chromium(III)–cobalt(II) (2) separation across the oxalate bridge are 5.5233(14) [Cr(1)…Mn(1)], 5.5735(14) [Cr(1)…Mn(1b)] and 5.3681(11) Å [Cr1⋯Co(1)]. The investigation of the magnetic properties of 1 and 2 in the temperature range 1.9–300 K reveals the occurrence of significant ferromagnetic interactions between the chromium(III) and the high-spin manganese(II) (1)/cobalt(II) (2) across the oxalate bridge. Monte Carlo simulations were used to evaluate the intrachain magnetic interaction in 1. Simple molecular orbital analysis of the exchange interactions in 1 and 2 identify the σ- and π-type pathways involving the d(x2 − y2) (Mn and Co)/d(xy) (Cr) and d(xz) (Cr)/d(yz) (Mn and Co) pairs of orthogonal magnetic orbitals as the main individual contributions accounting for the overall ferromagnetic couplings in these compounds.RésuméDeux nouveaux complexes de formule {[Cr(pyim)(ox)2]2Mn}n·2nCH3OH (1) et {[Cr(pyim)(ox)2]2Co(H2O)2}·7.5H2O (2) [pyim = 2-(2′-pyridyl)imidazole et H2ox = acide oxalique] ont été synthétisés en utilisant le complexe mononucléaire de chrome(III) PPh4[Cr(pyim)(ox)2]·H2O (PPh4+ = tetraphenylphosphonium) en tant que métaloligand vers les perchlorates des cations manganèse(II) (1) et cobalt(II) (2) hexahydratés. La structure du composé 1 contient des double chaînes neutres avec des unités de type diamant où les atomes de manganèse sont partagés et les deux autres sommets sont remplis par les atomes de chrome. Chaque unité [CrIII(pyim)(ox)2]− du complexe 1 agit comme coordinat vers deux ions manganèse(II) à travers ses deux groupes oxalate. Le complexe 2 contient des entités trinucléaires centrosymétriques où deux unités périphériques [CrIII(pyim)(ox)2]− agissent comme ligands bidentés vers un cation diaquamanganèse(II) à travers un de ses deux oxalates. Les valeurs des distances Cr(III)⋯Mn(II) (1) et Cr(III)⋯Co(II) (2) à travers le pont oxalate sont 5.5233(14) [Cr(1)…Mn(1)], 5.5735(14) [Cr(1)…Mn(1b)] et 5.3681(11) Å [Cr1⋯Co(1)]. L’étude de leurs propriétés magnétiques en fonction de la température montre l'existence d'interactions ferromagnétiques intrachaînes (1) et intramoléculaires (2). Des simulations de type Monte Carlo ont été utilisées pour l'estimation de la valeur de l'interaction d’échange du composé 1. Une analyse orbitalaire a permis de mettre en évidence les voies d’échange σ et π concernant les couples d(x2 − y2) (Mn et Co)/d(xy) (Cr et d(xz) (Cr)/d(yz) (Mn et Co), lesquelles sont les contributions les plus importantes vis-à-vis des interactions ferromagnétiques observées.Graphical abstractImage 1
       
  • Low-cost ceramic membranes: Synthesis, classifications, and applications
    • Abstract: Publication date: Available online 25 October 2018Source: Comptes Rendus ChimieAuthor(s): Mansour Issaoui, Lionel Limousy The elaboration of porous ceramic membranes using low-cost materials has attracted much interest. Indeed, the choice of suitable raw materials (including additives or binders) is critical to the membrane's performance. However, with the growing need for more cost-effective resources with superior performance, many studies have been conducted for selecting suitable cheap raw materials for the intended use and then adjusting the overall characteristics, and therefore allowing the ceramic membranes to be tailored to suit a wide range of industrial applications. Many attempts have been made by researchers to produce porous ceramic membranes from specific materials, but their industrial applications remain very limited because of the high cost of the raw materials used. The use of ceramic materials for producing membranes has many advantages, such as high mechanical and chemical stability and excellent thermal resistivity. The evaluation of membrane performances, essentially their permeability and rejection, can assert their use in many industrial fields, namely beverage and food, pharmaceutical, biotechnology, petrochemical industries as well as water treatment and several other environmental problems. This article aims to make a thorough review of the different processes used in the synthesis of ceramic membranes using inexpensive raw materials as well as their intrinsic characteristics and industrial applications in several sensitive fields taking into account both economic and environmental aspects.
       
  • Removal of fluoride from groundwater using natural clay (kaolinite):
           Optimization of adsorption conditions
    • Abstract: Publication date: Available online 23 October 2018Source: Comptes Rendus ChimieAuthor(s): Nouria Nabbou, Meriem Belhachemi, Mustapha Boumelik, Touhami Merzougui, Driss Lahcene, Yahia Harek, Antonis A. Zorpas, Mejdi Jeguirim This article focuses on the application of clay, kaolinite, for the removal of fluoride ion from Saharan groundwater located in the Tindouf region (Algeria) because high concentrations are detected in potable water. Adsorption tests show that fluoride ion removal was efficient when the pH varies from 4.5 to 6. Under these conditions, the adsorption capacities were 0.442 and 0.448 mg/g, respectively. Kinetic and isotherm adsorption correlations were applied to describe the adsorption process. The results showed that the pseudo-second-order kinetic model and Freundlich isotherm fit well the experimental data. Thermodynamic calculation indicated that fluoride sorption into clay increased with increasing temperature from 30 to 55 °C, indicating the endothermic nature of sorption process. The investigation of the removal of fluoride from simulated potable water shows that the presence of nitrate and chloride ions did not influence the fluoride uptake. However, sulfate and carbonate ions decrease the adsorption capacity. Such results show that these ions may enter in competition with each other that may result in electrostatic repulsive forces between fluoride and clay surface. From this study, it can be concluded that the kaolinite is an effective and low-cost material for the removal of fluoride ions from groundwater.
       
  • Filtration of protein-based solutions with ceramic ultrafiltration
           membrane. Study of selectivity, adsorption, and protein denaturation
    • Abstract: Publication date: Available online 19 October 2018Source: Comptes Rendus ChimieAuthor(s): Simona M. Miron, Patrick Dutournié, Kawther Thabet, Arnaud Ponche Proteins are widely used in food or pharmaceutical industry and are often pumped in complex flow systems. Their biological activity is intrinsically related to their conformation in solution. In this work, we studied the state and behavior of proteins in solution during separation/concentration operation in terms of adsorption, molecule agglomeration, and denaturation. Solutions of lysozyme have been filtrated on a ceramic ultrafiltration membrane at high flow velocity and different transmembrane pressures to investigate the effect of flow parameters on the protein conformation in solution assessed by size-exclusion chromatography. A shift of 0.4 min in elution time of the peak corresponding to lysozyme is observed between retentate and permeate solutions, indicating that the lysozyme molecules exhibit drastic conformation changes after filtration. In addition, the effect of the filtrated solute nature on the pore surface (adsorption phenomena) is investigated by following the evolution of the hydraulic and selectivity membrane performances.ResumeLes solutions contenant des protéines sont souvent utilisés dans les industries pharmaceutiques et agroalimentaires, et sont souvent manipulées dans des systèmes fluides complexes. Leur activité biologique est directement reliée à la conformation des molécules en solution. Dans cette étude, l'état et le comportement de protéines en solution ont été étudiés lors d'opérations de séparation à travers les propriétés d'adsorption, d'agglomération et de dénaturation des protéines. Des solutions de lysozyme ont été filtrées avec une membrane céramique d'ultrafiltration à bas seuil de coupure pour étudier l'effet des paramètres opératoires (vitesse, pression) sur la conformation de la protéine. Les résultats obtenus par chromatographie liquide d'exclusion stérique montre un décalage de 0.4 min du pic correspondant à la lysozyme après filtration, indiquant une modification importante de sa conformation. En parallèle, les phénomènes d'adsorption sont étudiés en suivant les propriétés hydrauliques et de sélectivité de la membrane.
       
  • Insight into surface and structural changes of montmorillonite and
           organomontmorillonites loaded with Ag
    • Abstract: Publication date: Available online 11 October 2018Source: Comptes Rendus ChimieAuthor(s): Alejandra M. Fernández Solarte, Jhonny Villarroel-Rocha, César Fernández Morantes, Maria L. Montes, Karim Sapag, Gustavo Curutchet, Rosa M. Torres Sánchez A raw montmorillonite (MMT) and three organomontmorillonites (OMMTs) with different amounts of hexadecyltrimethylammonium bromide (HDTMABr), and further silver loading (MMT–Ag or OMMT–Ag) were used to study their surface and structural changes and fungicidal activity. For OMMT and OMMT–Ag samples, the specific surface area and micropore amount decreased with the increase in surfactant loading, whereas textural properties remained constant. Surfactant entrance into the interlayer with the increase in surfactant loading was irrespective of Ag loading, whereas a decreasing number of stacked clay platelets and loss of surfactant were found after Ag incorporation. Ag nanoparticles of different sizes and large silver aggregates found in OMMT–Ag altered the electric surface charge as compared with the OMMT samples. Although the surfactant loading up to actual 100% of the MMT cation exchange capacity decreased silver retention, for MH2–Ag sample (with 200% HDTMA loaded with respect to the MMT's cation exchange capacity, and further Ag loading) silver retention was close to that of MMT and null silver lixiviation could be assigned to the HDTMA–Ag complex and AgBr formation. Fungicidal activity was correlated with surfactant loading, increasing with Ag addition.
       
  • Organoclay applications and limits in the environment
    • Abstract: Publication date: Available online 9 October 2018Source: Comptes Rendus ChimieAuthor(s): Régis Guégan This article gives an overview of the preparation, applications, and limits of organoclay materials in the environment field. Organoclays are obtained by the combination of clay minerals and surfactants (quaternary alkyl ammonium salts and others) and are appropriate candidates for the adsorption of organic contaminants such as pesticides, herbicides, and pharmaceuticals that are more and more found in the water resource despite wastewater treatments. This review article focuses on novel organoclay preparation methods based on the use of nonconventional nonionic surfactants and the interest and limits of these hybrid materials for the adsorption of organic compounds at both batch equilibrium and dynamical percolation experimental conditions.
       
 
 
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