Russian Journal of General Chemistry最新文献

Cerium oxide nanoparticles were synthesized via a green method using Camphora leaf extract. Comprehensive characterization of the biosynthesized nanoparticles was conducted using XRD, UV-Vis, TEM, DLS, FT-IR, BET, PL and photocatalytic analyses. X-Ray diffraction confirmed the cubic crystalline structure of CeO₂ with a crystallite size of 19±2 nm. UV-Vis spectroscopy showed a sharp absorption peak at 352 nm and minimum band gap of 3.52 eV, indicating strong photocatalytic potential. Both TEM and DLS analyses revealed that the majority of the particles were spherical, with an average size ranging from 20 to 21 nm, and moderate agglomeration. FT-IR analysis verified the involvement of phytochemicals in both the formation and stabilization of the biosynthesized nanoparticles. BET and BJH measurements demonstrated that the material possesses a high surface area and mesoporous structure, with an average pore diameter of 5 nm. PL spectra indicated that oxygen vacancies and other structural defects play a crucial role in enhancing charge carrier separation. Using sunlight as the irradiation source, the biosynthesized CeO₂ nanoparticles achieved 91% degradation of methylene blue dye within 90 min. The catalyst demonstrated good stability across multiple reuse cycles, confirming their suitability for wastewater treatment applications. Overall, the experimental findings validate that this environmentally friendly synthesis approach can reliably produce highly active photocatalysts.

2-Styrylpyridinium salts containing adamantane or aromatic fragments were prepared via a substitution reaction. It was found that quaternized substituted 2-ethenylpyridines undergo intramolecular cyclization under the action of bases, leading to trisubstituted cyclopropanes, as well as mono-, di-, and trisubstituted indolizines. A plausible mechanism was proposed for the formation of pyridylcyclopropanes.

The identification, synthesis, and control of process-related impurities in active pharmaceutical ingredient (API) development are critical for regulatory compliance and process optimization. During the manufacturing of Bis-Boc-lisdexamfetamine, five impurities Boc-Lys(H)-D-amphetamine, Boc-lisdexamfetamine, and three diastereomeric Bis-Boc-lisdexamfetamine isomers were detected at an advanced stage. A refined process was developed to effectively minimize these impurities within ICH-specified limits. This study details the analytical strategies used to trace impurity origins, establish process controls, and optimize synthesis. The impurities were synthesized, characterized using spectroscopic techniques (¹H, ¹³C NMR, mass-spectrometry, and IR spectroscopy), and successfully controlled in the final process, ensuring robust impurity management for commercial manufacturing.

Preparative methods were developed for the synthesis of 4,7-diaryl-3,4-dihydropyrido[4,3-d]pyrimidin-2(1H)-ones based on readily available Biginelli products. Optimal conditions for the reaction of 4-aryl-6-styryltetrahydropyrimidine-5-carbaldehydes with ammonium salts were selected, enabling the preparation of substituted pyrido[4,3-d]pyrimidinones in yields up to 57%. An alternative synthetic route involving oxime formation followed by cyclization under the action of DBU was also studied.

Nitrate pollution in water bodies is becoming increasingly severe and has become an urgent issue to address. Electrocatalytic reduction is a green and environmentally friendly technology that can convert nitrates into NH₃ and N₂. To tackle the diversity of nitrate products from electrocatalytic reduction, this study first systematically elucidates the reaction mechanism, then analyzes the products, and finally reviews methods to improve N₂ selectivity from aspects such as the reaction mechanism and cathode materials. It delves into the impact of cathode element selection, alloy doping, and structural design on N₂ selectivity, aiming to provide guidance for research on electrocatalytic reduction of nitrate wastewater.

A simple and selective method for separating, preconcentrating, and determining trace amounts of Zn(II) using cloud point extraction and ICP-MS was described. In this process, Zn(II) in an aqueous solution is complexed with biphenyl thiacalix[4]arene hydroxamic acid (BPTC4HA) at an optimal pH of 8.5. Triton X-100 is used as a surfactant, and Na₂SO₄ is added to lower the cloud point temperature. Phase separation occurs at 45°C, after which the surfactant-rich phase is diluted with acetonitrile-ethanol. Zn (II) is then measured spectrophotometrically at λ_max = 330 nm and the extract is inserted into plasma for online ICP-MS measurements. Variables such as pH, temperature, surfactant concentration and reagent concentration were optimized. The method’s selectivity for Zn(II) amidst other ions was examined. Additionally, a transport study using a membrane with a 0.1N HNO₃ stripping agent showed 99.9±0.5% transport efficiency for Zn(II) with a half-life of 9.8 min. The detection limit for Zn(II) using spectrophotometry is 0.09 µg/mL, with a quantification limit of 0.3 µg/mL, while ICP-MS enhances sensitivity with a detection limit of 0.05 ng/mL and a quantification limit of 0.16 ng/mL. The method’s reliability was confirmed by testing standard, food, and environmental samples.

Oligomeric poly Brassica juncea oil fumarate (o-PMF) polyester composites have been created by combining fumarate resin and agave sisalana fibers. The polyester composites were characterized using FT-IR, swelling coefficient, crosslink density, solvent absorptivity percentage and thermal analysis. The mechanical parameters of the composites were examined, including tensile strength, young’s modulus, shore A hardness, and elongation at break. The specimens for the aforementioned tests were prepared according to ASTM standards. The fiber reinforced polyester composites improved the mechanical characteristics of polyesters, and the surface morphology of the polyester was examined using a scanning electron microscope. The results of the investigations demonstrated that the newly created cross-linked poly brassica juncea oil fumarate polyesters are prospective biodegradable materials for various consumer applications such as package materials, automobile, pharmacy and agricultural applications.

A series of novel oxadiazole-imidazole scaffolds were successfully synthesized using a one-pot synthesis method. Thus, synthesized compounds were characterized by FT-IR, ¹H, ¹³C NMR, and LC-MS techniques. The biological activities of these compounds are evaluated through in vitro studies, including anti-inflammatory activity assessed by the denaturation of bovine serum albumin (BSA) and antioxidant activity determined by the DPPH free radical scavenging assay. One of the compounds exhibited the most potent activity with IC₅₀ values of 25.5 µM for anti-inflammatory and 30.1 µM for antioxidant activity, surpassing the efficacy of standard drugs used in this investigation. Additionally, molecular docking studies were conducted using Human peroxiredoxin 5 revealing that the same compound demonstrated favorable binding interactions. These findings reveal that this compound is a promising candidate for further development as a drug-like candidate.

A new approach was proposed for the synthesis of the 3H-benzo[d][1,2]oxaphospholes ethyl esters by the three-component acid-catalyzed reaction of triethylphosphite with carbonyl compounds and phenols. It allows obtaining target structures in one synthetic step from available reagents. Trifluoromethanesulfonic acid was shown to be an effective catalyst for the process.

Synthesis and structure of mixed Schiff base derived from 2,3-diaminopyridine were described. Fluorescence in the powder, chloroform solution and polymer matrices was observed. The amphoteric properties of this compound were studied.