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Two highly ordered isonicotinamide (INA)‐functionalized mesoporous MCM‐41 materials supporting indium and thallium (MCM‐41‐INA‐In and MCM‐41‐INA‐Tl) have been developed using a covalent grafting method. A surface functionalization method has been applied to prepare Cl‐modified mesoporous MCM‐41 material. Condensation of this Cl‐functionalized MCM‐41 with INA leads to the formation of MCM‐41‐INA. The reaction of MCM‐41‐INA with In(NO3)3 or Tl(NO3)3 leads to the formation of MCM‐41‐INA‐In and MCM‐41‐INA‐Tl catalysts. The resulting materials were characterized using various techniques. These MCM‐41‐INA‐In and MCM‐41‐INA‐Tl catalysts show excellent catalytic performance in the selective oxidation of sulfides and thiols to their corresponding sulfoxides and disulfides. Finally, it is found that the anchored indium and thallium do not leach out from the surface of the mesoporous catalysts during reaction and the catalysts can be reused for seven repeat reaction runs without considerable loss of catalytic performance. 相似文献
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Karam Asad Dr. Anastasios Stergiou Dr. Andreas Kourtellaris Prof. Nikos Tagmatarchis Prof. Nikos Chronakis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(55):13879-13886
The multiaddition chemistry of azafullerene C59N has been scarcely explored, and the isolation of pure bisadducts is in its infancy. Encouraged by the recent regioselective synthesis of the inherently chiral equatorialface bisadduct of C59N, we focused on the isolation of the first trans-4 bisadduct in a simple two-step approach. The first regioselective synthesis of the trans-4 bisadduct of C59N by using cyclo-[2]-dodecylmalonate as a tether is now reported. The newly synthesized bisadduct has C1 symmetry, as evidenced by 13C NMR, while X-ray crystallography validated the trans-4′ addition pattern. Furthermore, the inherently chiral trans-4′ C59N bisadduct was enantiomerically resolved, and the mirror-image relation of the two enantiomers was probed by circular dichroism spectroscopy. Finally, UV-Vis and redox assays suggested that the addition pattern has a reflection in the light-harvesting and redox properties of the bisadduct. 相似文献
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The Ramanujan Journal - Let $$s_{q}$$ denote the sum of digits function in base q. The aim of this work is to estimate the exponential sums involving the sum of digits of shifted integers, namely... 相似文献
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Hamoud Moustafa A. Allan Karam F. Sanad Wafaa A. Saad Ebtissam A. Mahmoud Mamdoh R. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(2):647-661
Polyacrylonitrile/ferrocyanide composite incorporated with cetrimonium bromide (PFICB) was synthesized and evaluated as a novel bifunctional adsorbent for coremoval of Cs+ and HCrO4?. Results of the reaction time effect showed that adsorption of Cs+ and HCrO4? onto PFICB were rapid processes. The effect of the solution pH in the range 2.5–10 revealed that PFICB had the ability to simultaneously remove Cs+ and HCrO4?. The maximum adsorption capacity of PFICB was found to be 41.79 mg/g for Cs+ and 19.39 mg/g for HCrO4?. These values were compared with those reported in literature using other adsorbents.
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Emeline Appert Dr. Agnès Martin-Mingot Dr. Omar Karam Dr. Fabien Zunino Dr. Bastien Michelet Dr. Fodil Bouazza Prof. Sébastien Thibaudeau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(49):e202201583
The field of medicinal chemistry is currently witnessing a deuterium rush owing to the remarkable properties of this element as bioisoster of hydrogen atom. Aromatic hydrogen isotope exchange (HIE) is one of the most studied strategies nowadays as it promises to access deuterium-modified drugs directly from their non-labeled parents. While most of the recent studies focus on metal-catalyzed C−H activation strategy, the use of superacidic conditions has been largely overlooked. This study shows that the use of TfOD as reaction medium allows the late-stage polydeuteration of a broad library of pharmaceuticals bearing a wide array of functional groups, complementing existing procedures. 相似文献
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Iyad Karamé Esen Bellur Sven Rotzoll Peter Langer Christine Fischer Jens Holz 《合成通讯》2013,43(7):1067-1076
Highly enantioselective hydrogenation of β‐alkyl and β‐(ω‐chloroalkyl) substituted β‐keto esters was achieved with Ru catalysts based on chiral diphosphines in EtOH at 50°C under 50‐bar initial hydrogen pressure, affording the corresponding β‐hydroxy esters in >98% ee. 相似文献
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Marco Deiana Karam Chand Jan Jamroskovic Ikenna Obi Erik Chorell Nasim Sabouri 《Angewandte Chemie (International ed. in English)》2020,59(2):896-902
The design of turn‐on dyes with optical signals sensitive to the formation of supramolecular structures provides fascinating and underexplored opportunities for G‐quadruplex (G4) DNA detection and characterization. Here, we show a new switching mechanism that relies on the recognition‐driven disaggregation (on‐signal) of an ultrabright coumarin‐quinazoline conjugate. The synthesized probe selectively lights‐up parallel G4 DNA structures via the disassembly of its supramolecular state, demonstrating outputs that are easily integrable into a label‐free molecular logic system. Finally, our molecule preferentially stains the G4‐rich nucleoli of cancer cells. 相似文献
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M.R. Bayati Roya Molaei F. Golestani-Fard 《Colloids and surfaces. A, Physicochemical and engineering aspects》2011,373(1-3):51-60
This study sheds light on the effect of vanadium doping on hydrophilicity properties of micro arc oxidized TiO2 porous layers. Pure and V-doped titania layers, with a pore size of 50–400 nm, were grown by micro arc oxidation method. Morphology and topography of the layers were studied by SEM and AFM techniques where formation of a porous structure with a rough surface was confirmed. Moreover, phase structure and chemical composition of the samples were investigated employing XRD and XPS techniques. The pure TiO2 layers consisted of anatase and rutile phase. Vanadia phase was also detected in V-doped layers. It was also revealed that V2O5 not only dispersed in the TiO2 matrix, but also doped into the crystalline lattice. Optical properties and band gap energy of the synthesized layers were evaluated by a UV-Vis spectrophotometer. Our results showed that the band gap energy decreased when vanadium was introduced into the titania lattice. Finally, hydrophilicity of the pure and the doped layers was studied under ultraviolet and visible illuminations by measuring the water contact angle on their surface. The V-doped layers, especially those which were grown under intermediate voltages, revealed an enhanced hydrophilicity when compared to the pure TiO2 layers. 相似文献