Có 20+ tài liệu thuộc chủ đề "Journal of Chemistry"
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Singlet oxygen generation from poly[4-diacetoxyiodo]styrene and hydrogen peroxide. Abstract:Treatment of hydrogen peroxide with a polymer-supported hypervalent iodine compound, poly[4-diacetoxyiodo]. Singlet oxygen generation was proved by trapping with typical organic compounds such as conjugated dienes, aromatic dienes, and electron-rich alkene. When compared to monomer analogue, the use of PDAIS in peroxidation of substrates gave slightly better yields (45%–96. Regeneration and reuse...
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Sodium dodecyl sulfate (SDS) was employed in a surface assembly mode to improve the sensitivity of the sensor response. The proposed sensor, NdFeO 3 in situ modified carbon paste electrode in the presence of SDS (NFMCpE-SDS), showed a higher current response towards ketotifen oxidation compared to other surfaces. The enhanced signal response is attributed to the catalytic properties of the...
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Calix[4]pyrroles with bulky substituents and their anion binding studies. Abstract: Calix[4]pyrrole derivatives with bulky substituents at their meso-positions were synthesized via mixed con- densation of pyrrole with cyclohexanone and acetophenone derivatives. Anion binding studies, carried out by isothermal titration calorimetry in 1,2-dichloroethane with Cl − and CH 3 CO − 2 anions in the form of their tetrabutylammonium salts, revealed...
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doi:10.3906/kim-1612-45 h t t p. Diastereoselective synthesis of novel 2,5-dioxopyrrolidine derivatives via biocatalytic domino reactions. Abstract: A series of novel 2,5-dioxopyrrolidines were synthesized by the one-pot reaction of coumarin-3-carboxylic acids 1 with thiourea derivatives and alkyl isocyanides in the presence of Fe 3 O 4 NPs @ lipase as heterogeneous reusable nanobiocatalysts with high yields.. Re- view of the literature...
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Adsorption isotherm modeling of carbendazim and flumetsulam onto homoionic-montmorillonite clays: comparison of linear and nonlinear models. Abstract: This study deals with the adsorption of two pesticides, carbendazim and flumetsulam, from aqueous solutions onto four homoionic-montmorillonite clays (Ag. Equilibrium adsorption isotherm data were analyzed using Freundlich, Dubinin–Radushkevich, and Temkin isotherms. Linear and nonlinear fitting methods were compared to determine the best-fitting...
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8.4 Hz, 3 J F H 8.8 Hz, H 2 ,H 6. 7.40 (dd, 2H, 3 J HH 8.4 Hz, 4 J F H 5.6 Hz, H 3 ,H 5. 130.10 (d, 3 J F C = 8.5 Hz, C 3, C 5. 65.84 (d, 2 J P C = 6.8 Hz, O-C H 2. 26.60 (d, 3 J P...
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Synchrotron X-ray diffraction studies of β -Ca 2 − x M x SiO 4 (M = Mg and Sr). Abstract: The structures of Mg- and Sr-doped β -Ca 2 SiO 4 have been established from high-resolution synchrotron X-ray powder diffraction. These silicates are all isostructural and the structures have been refined in the monoclinic space group, P 2 1 /...
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Online coupling electrochemical preconcentration and GFAAS technique as effective method for determination of ultratrace concentrations of antimony in. groundwater and surface water samples. Abstract: The present article describes a method of determination of low antimony concentrations using a graphite furnace AAS technique after electrochemical preconcentration. This cell worked in online coupling with the graphite furnace atomizer. Accumulation occurred from the...
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A rapid, efficient, and green synthesis of benzo[ a ]chromeno[2,3-c]phenazine derivatives via microwave assistance and DABCO catalyzed a novel domino. Abstract:An efficient, convenient, and environmentally benign procedure for the synthesis of novel benzo[a ]chromeno[2,3- c ]phenazine derivatives has been developed by domino four-component condensation reaction between 2-hydroxynaphtha- lene-1,4-dione, o−phenylenediamine, aromatic aldehydes, and naphthols or phenol in the presence of a...
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reactive orange 16 (RO 16) via ferrate(VI) and sono-ferrate(VI) methods, which is the combination of the ferrate(VI) oxidation method with sonication, has been achieved in the present study. 50 mg L −1 by direct sonication at 0.50 W mL −1 ultrasonic density and 20 kHz fixed frequency for the sono-ferrate(VI) method. by ferrate(VI) method and 91% by sono-ferrate(VI) method. Kinetic...
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Ultrasonic activation of the arylation reaction of styrene catalyzed by transition metals. Abstract:The arylation reaction of styrene was tested in the presence of different transition metal-based catalysts, mainly iron-based, given its low cost and its nonpolluting and nontoxic characteristics. The study of the effect of sonochemical activation on the evolution of the selectivity of the reaction is also proposed. Furthermore,...
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Abstract: Direct β -carbon activation of saturated carbonyl compounds for carrying out fast forward β -functionalization has been one of the most difficult to achieve tasks in catalysis. In the past few years, this challenging issue has attracted considerable attention among the chemical community that has led to fruitful developments to accomplish this elusive transformation. In this short review, we...
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A new method for simultaneous determination of trace amounts of Cu(II) and Ni(II) ions by preconcentration and spectrophotometric analysis. Abstract: Immediate preconcentration and spectrophotometric methods have been developed for the determination of trace amounts of cupric ion (Cu(II)) and nickel ion (Ni(II)) through a solid phase extraction with XAD-4-N,N’-bis- (salicylidene) cyclohexanediamine (XAD-4-SCHD) resin and a complex color reaction of the...
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Synthesis of phosphorus-containing polyurethanes and poly(urethane-acrylate)s. Abstract: Solvent-based polyurethanes and poly(urethane-acrylate)s were synthesized using phosphorus-containing polyester polyols in order to compare the thermal properties of different polymer types. Since the location of the phosphorus group might have vital importance when comparing the thermal properties, phosphorus groups were kept on the pendant chains in poly(urethane-acrylate)s using phosphorus-containing urethane macromonomers while they...
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Abstract: In the present work, a green emitting composite with attractive photoluminescent properties was ob- tained through the embedding of the Tb 3+ complex with N-hydroxyphthalimide in a poly-(N-vinyl-pyrrolidone) ma- trix, which was further processed in thin or thick films. and Y 3+ with N-hydroxyphthalimide with the general formula [M(NHF) 3 (DMF) 2 ] were prepared at a 1:3 metal/ligand...
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Abstract: Three modular types of bis(aminoalcohol)oxalamides (1, 4, and 7) and bis(aminoalcohol)diglycolylamide (8) gelators have been prepared by the reaction of the respective aminoalcohols with oxalyl and digycolyl methylesters as potential low-molecular-weight organogelators. Furthermore, the common oxalamide linker present in the gelators was replaced by an extended diglycolylamide linker (8) and its behaviors were compared with the benzylic oxalamide analog...
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The chemical structures of the compounds were elucidated by FT-IR, 1 H NMR, 13 C NMR, and HRMS spectral data. Among the tested compounds 2a–2d and 2f–2h (10 mg/kg) increased the maximum possible effect (MPE)% values calculated for the hot-plate and paw-pressure tests and decreased the paw licking time of rats in the early phase of the formalin test, indicating...
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IC 50 (MAO-B). The ADME prediction of the compounds revealed that they may have good pharmacokinetic profiles, which is necessary for drug candidates.. 5,12 − 16 The common structural feature of inhibitors in these studies was an amino or imino group, which seems to play an essential role in orientation and complex formation at the active site of the enzyme...
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Nanocomposite copper metal as an efficient heterogeneous catalyst in click synthesis of 1,2,3-triazoles in aqueous media. The reaction proceeds by mixing organohalides, sodium azide, alkyne, and the catalyst in an aqueous medium to afford the desired products. The cost efficiency and recyclability of the catalyst up to six runs without appreciable loss of activity and high yields of products make...
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7.57 (d,J = 8.50 Hz, 2H). 7.38 (t, J = 7.00 Hz, 2H). 7.32 (d, J = 8.00 Hz, 2H). 7.20 (d, J = 8.50 Hz, 2H). 7.02 (d, J = 8.00 Hz, 2H). H, 6.00. 7.50 (d,J = 7.50 Hz, 2H). 7.40 (d, J = 8.00 Hz, 2H). 7.35 (t, J = 7.50 Hz, 2H). 7.30 (d, J =...