Có 60+ tài liệu thuộc chủ đề "Journal of Chemistry"
tailieu.vn Xem trực tuyến Tải xuống
Spectrophotometric detection of rhodamine B in tap water, lipstick, rouge, and nail polish samples after supramolecular solvent microextraction. Abstract: A simple and sensitive supramolecular solvent-based dispersive liquid–liquid microextraction method was described for the separation/preconcentration and spectrophotometric detection of rhodamine B. The microextraction method, which was realized at ambient temperature for the detection of rhodamine B, was carried out by using...
tailieu.vn Xem trực tuyến Tải xuống
A simple and effective method for determination of the antithyroid drug carbimazole using ruthenium trichloride. Abstract: An accurate, precise, and simple spectrophotometric method is proposed for the determination of the antithyroid drug carbimazole using ruthenium(III) chloride. The metal:ligand (M:L) ratio of the complex was confirmed by the mole ratio and Job’s method of continuous variation, suggesting a 1:2 stoichiometry. Carbimazole,...
tailieu.vn Xem trực tuyến Tải xuống
The preparation of new hybrid molecules is significant because they can serve as a lead compound for the discovery and development of safer analgesic and antiinflammatory agents.. The mechanism for the antiinflammatory activity is the inhibition of prostaglandin synthesis. 16 In our work, we studied the hybrid molecules prepared by a combination of NSAIDs with other synthetic and natural molecules....
tailieu.vn Xem trực tuyến Tải xuống
doi:10.3906/kim-1705-33 h t t p. Thin films of metallophthalocyanines were obtained by spin coating technique. Optical measurements showed that transmittance values of metallophthalocyanine thin films obviously changed with respect to the metal ion in the phthalocyanines. Transmittance spectra of the phthalocyanines synthesized using different metal ions showed a variation of about 8% and 15% in transmittance spectra of the Q...
tailieu.vn Xem trực tuyến Tải xuống
Facile synthesis of heteroaryl substituted γ -lactams from nitrovinyl arenes. Abstract: Aliphatic nitroalkanes with different functional groups were synthesized from the Michael addition reactions of active methylene compounds 2 and nitrovinyl arenes 1 in high yields. Herein, we report the formation of γ -lactams 4 from the intramolecular cyclization reactions of Michael adducts 3 obtained from the reaction of active...
tailieu.vn Xem trực tuyến Tải xuống
Abstract: A new approach based on a selective charge transfer reaction with alizarin red S is described for the simulta- neous determination of azithromycin and levofloxacin in their binary mixtures using an absorption-factor spectrophoto- metric method. Native absorbance was used for the determination for levofloxacin, while a charge transfer complexation of alizarin red S served as the basis for the...
tailieu.vn Xem trực tuyến Tải xuống
The catalytic performance of different montmorillonite and organic modified montmorillonite catalysts was investigated in the dimerization of technical grade unsaturated fatty acid, and the influence of the catalyst structure and composition on the catalytic performance was analyzed. The results show that the layer spacing and dispersion property of the montmorillonite crystal have important effects on its catalytic performance and the...
tailieu.vn Xem trực tuyến Tải xuống
These targeted compounds were synthesized by the melt reaction between N -methylated-4-chloropyridinium triflate and corresponding amines (1-naphthyl amine, o -ansidine, 2-nitroaniline, p-ansidine, and cyclohexyl amine) followed by the addition of sodium hydride in dichloromethane in the same pot. These highly electron-donating N -(1-methylpyridin-4(1H ) -ylidene)amine ligands considerably improve the catalytic activity of palladium acetate towards Heck–Mizoroki carbon–carbon cross-coupling reactions.. Phosphines...
tailieu.vn Xem trực tuyến Tải xuống
Synthesis of benzaldehyde by Swern oxidation of benzyl alcohol in a continuous flow microreactor system. Dimethyl sulfoxide (Me 2 SO) was used as oxidizing agent and oxalyl chloride or p-toluenesulfonyl ( p -TsCl) chloride was used as the activating agent. Benzyl alcohol was oxidized to benzaldehyde by the Me 2 SO- activating agent mixture in the continuous flow microreactor system....
tailieu.vn Xem trực tuyến Tải xuống
Abstract: In this work, surface-functionalization agents and various salts as auxiliaries were used to improve the adsorption capacity of biochars produced via hydrothermal carbonization of glucose, cellulose, and hazelnut shell. The effect of surface functionalization with different acids and bases as well as neutral salts on the adsorption of methylene blue and methyl orange was investigated using Boehm titration, Fourier...
tailieu.vn Xem trực tuyến Tải xuống
Metallophthalocyanine complexes (4–7) were obtained by cyclotetramerization of 7-tert-butyldibenzo [b,e] [1,4] dioxine-2,3-dicarbonitrile. The electronic data of the new compounds were obtained by computational calculations at the B3LYP/6-31G (d,p) level of theory.. The solubility can be increased by introducing different kinds of solubility- enhancing substituents such as alkyl, phenoxy, and alkoxy groups at the axial and peripheral positions of the Pc...
tailieu.vn Xem trực tuyến Tải xuống
Gas permeability of polydimethylsiloxane membranes filled with clinoptilolite in different cationic forms. Abstract: Zeolite-polymer mixed matrix membranes were prepared by filling polydimethylsiloxane (PDMS) with clinop- tilolite in various cationic forms of K, Mg, H, and Na. The results indicated the presence of an optimum zeolite loading in the mixed matrix membranes maximizing permeability. The type of the cationic form of...
tailieu.vn Xem trực tuyến Tải xuống
The first objective of this work is to evaluate the physicochemical characteristics of the membrane used in experiments by determination of the exchange capacity, water uptake, ionic conductivity, and transport number (Hittorf method). current density, and the pH of the solution to evaluate the effectiveness of the electrodialysis defluoridation process. The high percentage of defluoridation obtained after treatment of industrial...
tailieu.vn Xem trực tuyến Tải xuống
Nanocapsulation of herbicide Haloxyfop-R-methyl in poly(methyl methacrylate):. The herbicide loading and encap- sulation efficiency were also analyzed for the herbicide-loaded nanocapsules. The plant growth rate, photosynthetic pigment contents, and activities of antioxidant enzymes were evaluated as indices to assess the effects and toxicity of the encapsulated Haloxyfop-R-methyl and its nonencapsulated form on Lemna minor. The obtained results confirmed that the...
tailieu.vn Xem trực tuyến Tải xuống
Abstract: Coumarinyl 1,3,4-oxadiazoles were synthesized from Schiff bases and acetic anhydride. Dolman et al. Dobrota et al. Our intention was to synthesize novel 1,3,4-oxadiazoles from coumarinyl Schiff bases and to investigate them in terms of their antibacterial, antifungal, and antiaflatoxigenic activity. Coumarinyl 1,3,4-oxadiazoles were synthesized from corresponding Schiff bases (Figure 1) and their structures were confirmed by 1 H NMR,...
tailieu.vn Xem trực tuyến Tải xuống
Kinetics of silver(I)-catalyzed oxidation of allyl alcohol by peroxodiphosphate in acetate buffers. Abstract: The kinetics and mechanism of silver(I)-catalyzed oxidation of allyl alcohol with peroxodiphosphate in acetate buffers have been studied. The rate is independent of allyl alcohol concentration. The rate law accounting for all experimental observations corresponds to the proposed mechanism. Peroxodiphosphate (PDP) is considered to be isoelectronic and...
tailieu.vn Xem trực tuyến Tải xuống
Cu(II) immobilized on Fe 3 O 4 @Agarose nanomagnetic catalyst functionalized with ethanolamine phosphate–salicylaldehyde Schiff base: a magnetically reusable. Abstract: Herein we synthesized Cu(II) immobilized on Fe 3 O 4 @Agarose functionalized with ethanolamine phosphate–. Preparation of Cu(II) immobilized on Fe 3 O 4 @Agarose nanomagnetic catalyst functionalized with ethanolamine phosphate–salicylaldehyde Schiff base (Fe 3 O 4 @Agarose/SAEPH 2 /Cu(II)).....
tailieu.vn Xem trực tuyến Tải xuống
Is there still a need to report the direct causal link of anthropogenic carbon dioxide CO 2 emissions to global warming? Addressing these critical issues is now urgent and one of the ways is to develop sustainable energies while widening their use. Sodium borohydride was discovered in the 1940s at the University of Chicago under the auspice of the US...
tailieu.vn Xem trực tuyến Tải xuống
The method for the synthesis of the carbazole Schiff base was based on the condensation of carbazole-3-carbaldehyde with 4-nitro-o- phenyldiamine in dimethylformamide in a moderate yield. The structure of the final compound was characterized by 1 H NMR, 13 C NMR, IR, mass spectrometry, and single crystal X-ray diffraction. The final compound exhibited exceptional selective and sensitive turn-on fluorescence response...
tailieu.vn Xem trực tuyến Tải xuống
Abstract: An efficient synthetic route for a novel series of chalcones 2a–2d as well as for the corresponding flavanones 3a–3d and flavones 4a–4d, using functionalized tetrahydronaphthalene (THN), is described herein. selectively gives the expected chalcones 2a–2d, which may further undergo an intramolecular oxa-Michael addition using piperidine, affording the corresponding flavanones 3a–3d in high yields. Alternatively, treatment of such chalcones 2a–2d...