Russian Journal of General Chemistry最新文献

This research was carry out to evaluate the thermo-oxidative and photo-oxidative stability of industrially important vinyl polymers poly(methyl methacrylate) and polystyrene obtained by radical-initiated polymerization in the presence of some metal complexes. Under conditions characteristical of practical polymer operation, the thermal oxidative stability of PMMA obtained on ferrocene, titanocene dichloride and zirconocene dichloride increases by 27–49°C. PMMA and PS obtained by free-radical polymerization, and PMMA(FC), PMMA(TC), PMMA(ZC), PS(TC) may be characterized as relatively resistant to photo-ageing.

Carbon dioxide utilization is an excellent strategy to control the rising concentration of carbon dioxide in the atmosphere. Its success relies on the effectiveness of carbon dioxide capturing and separation from emission points. Coal and natural gas-firing thermal power plants are the major causes of carbon dioxide emissions. This emphasizes the importance of techniques that effectively capture carbon dioxide from thermal power plants. Following capture, the separation of carbon dioxide from the flue gas mixture is also important to achieve ultrapure carbon dioxide suitable for chemical synthesis. Therefore, this minireview presents the techniques available for carbon dioxide capturing and separation. Also, the utilization methods of carbon dioxide are briefly outlined along with their merits and demerits. Special emphasis is given to the role of biochar materials in separating carbon dioxide from flue gas. We believe that this review will give an overview of carbon dioxide capturing, separation, and utilization methods.

Cost-effective mullite porous ceramic membrane supports were prepared from molybdenum tailings with high silica content by in situ reaction at high temperature. The effects of activated carbon content (as a pore-forming agent), molybdenum tailings content, and the sintering system on the phase composition, microscopic morphology, open porosity, flexural strength of the ceramic membrane supports were systematically investigated. The preferred conditions identified in this work are: 6 wt % of activated carbon and 55 wt % of molybdenum tailings, sintering temperature of 1200°C and holding time of 2 h. They obtained a support with an open porosity of 17.6% and a flexural strength of 79.5 MPa. Compared with pure alumina porous ceramics, the sintering temperature in this experiment can be lowered by about 600°C and the flexural strength can be increased by about 30 MPa. Meanwhile, the consumption of raw materials is reduced, which drastically cuts production cost and benefits the environment.

3-Carbohydrazide-5-C-(l,4-anhydro-β-D-erythro-tetrofuranosyl)-2-methylfuran underwent acid-catalyzed condensation reaction with some monosaccharides to form the corresponding C-furyl sugar hydrazone derivatives. Acetylation of the latter product with acetic anhydride at room temperature produced corresponding O-acylated sugar hydrazones in excellent yield. While C-furyl sugar hydrazones derivatives reacted under reflux with acetic anhydride undergo cyclization to produce the corresponding oxadiazolines in high yield. Further, 3-сarbohydrazide derivative condensed with some aromatic aldehydes afforded the corresponding sugar hydrazones. Evaluation of antimicrobial activity against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Aspergillus niger and Candida albicans showed that sugar hydrazones analogues were the highly active compounds and some of them showed the most promising inhibition activity against the microorganisms. The antitumor activity against breast cancer (MCF7) cell line also showed highly significant effect.

A novel class of 4-{[5-(benzylthio)-1,3,4-oxadiazol-2-yl]methyl}-2H-benzo[b][1,4]thiazin-3(4H)-one derivatives were designed, synthesized and screened for their in vitro antibacterial activities against Pseudomonas syringae pv. Actinidiae (Psa) and Xanthomonas axonopodis pv. Citri (Xac). Preliminary bioactivity test results indicated that some compounds showed moderate to good inhibitory effects against the tested bacteria at the concentrations of 100 and 50 μg/mL. Among them, 4-({5-[(4-fluorobenzyl)thio]-1,3,4-oxadiazol-2-yl}methyl)-2H-benzo[b][1,4]thiazin-3(4H)-one and 4-[(5-{[4-(trifluoromethyl)benzyl]thio}-1,3,4-oxadiazol-2-yl)methyl]-2H-benzo[b][1,4]thiazin-3(4H)-one exhibited the best inhibitory effects against Psa and Xac than other compounds, which showed a broad range of antibacterial activities. Further bioactive applications of these molecules are in progress in our laboratories.

Energy supply is a crucial topic that is currently being discussed in many countries for an assortment of applications, encompassing medical, transportation, and communication. Consequently, many chemists are eager to propose superior materials and components for the fabrication of devices with positive electrochemical performances. It is important to remember that the efficacy of electrochemistry determines the material utilized in energy supply devices like supercapacitors. Many chemists are motivated by this to develop appropriate materials and composites for energy gadgets. Composites of nanocarbon conducting polyaniline show promise as electrode ingredients for these kinds of energy storage classifications. Composite hybrids are predicted to have a noteworthy impression on the clean and efficient energy systems of the future because of their stability in a foreseeable environment, inexpensive, and high electroactivity, and pseudo-capacitance polymers. An outline of recent studies and significant developments regarding the fabrication of conducting polyaniline-based hybridized nanocomposite electrodes for supercapacitors is presented in this article. The electrochemistry of functionalized polyaniline polymer nano-composites is discussed in this manuscript due to its wide-ranging effects on energy production through strong redox reactions. Here, we have focused on developing polyaniline-based nanocomposite architectures that have been altered to advance them technologically through allied pendant sulfonic acid groups, carbonaceous materials, and transition metal oxide groups. These materials are very effective in today’s energy supply devices because of their ion exchange, low reaction energy, and simple electrochemical reactions. Discussions are held regarding the difficulties and viewpoints associated with the logical design and production of polyaniline hybridized nanocomposites for energy storage. This could be a future innovation that helps administrators maintain control and a balanced approach to further meet practical needs.

In order to develop compounds with anticancer potential, a novel series of 3-aryl-6-(thiophen-2-yl)-[1,2,4]triazolo[4,3-b]pyridazine derivatives was synthesized. The synthesis was carried out via the use of environmentally benign hypervalent iodine reagent in aqueous media. The SRB assay was employed for the evaluation of anti-cancer potential against MCF-7 carcinoma cell line. Compounds with furan and 2,5-dimethoxyphenyl substituents at the triazole ring showed admirable anticancer potential with GI₅₀ value less than 10 μg/mL. Compounds with 2-chlorophenyl, 3,4-dimethoxyphenyl, 4-methylphenyl and 4-isopropylphenyl substituents showed moderate potential with GI₅₀ values of 14, 54, 77, and 51 respectively. The two most active compounds were further studied via molecular docking against six proteins (PDB ID: 1E31, 1FDW, 1M17, 2W3L, 5GWK, and 6CBZ). The calculated binding energies and interactions in silico studies indicated the synthesized compounds to be potential EGFR inhibitor. Overall, this study highlighted the potential of the newly prepared analogues as promising leads for further development.

The synthesis and antibacterial evaluation of a new class of hydrophilic ocotillol-type triterpenoid derivatives have been conducted, with some of the compounds demonstrating potent activity (2–32 µg/mL) against a spectrum of pathogens including drug-resistant bacteria MRSA USA300. Assessing the synergistic potential, two compounds, substituted with C¹² aminopropionyl and aminovaleryl respectively, were identified to enhance the efficacy of kanamycin and chloramphenicol against MRSA USA300 and B. subtilis 168, achieving a fractional inhibitory concentration index (FICI) below 0.5. Time-kill kinetics studies confirmed that compound substituted with C¹² aminovaleryl, at a 2×MIC concentration, could rapidly eliminate MRSA cells. Further exploration into the mechanism of action revealed that this compound targets bacterial cell membranes, causing structural disruption, leakage of cellular contents, and ultimately, cell death. Its low toxicity to mammalian cells was evidenced by IC₅₀ values of approximately 70 µg/mL for HeLa cells and around 100 µg/mL for HEK-293 cells. Moreover, it was found to inhibit MRSA growth rapidly without promoting significant bacterial resistance. The drug-likeness properties and ADME prediction suggested that the tested compounds, with the exception of their molecular weights, conformed to Lipinski’s rule and exhibited moderate to good oral bioavailability. In vivo studies in a murine corneal infection model substantiated the robust antibacterial activity of this compound against S. aureus RN4220, particularly at higher doses. Lastly, a thorough analysis of the structure-activity relationships (SAR) among the synthesized compounds was conducted, providing valuable insights that could inform the development of novel therapeutic agents beyond the existing classes of antimicrobials.

The recyclization of 3-benzylidenephthalide during the reaction with monoethanol-, thioethanol-, allyl- and benzylamines into N-substituted derivatives of isoindol-1-one was studied. The dependence of the structure of the products on the reaction conditions and the nature of the amine component was revealed. 3-Hydroxy-3-benzyl-2-(2-hydroxyethyl)- and 3-hydroxy-3-benzyl-2-(2-mercaptoethyl)isoindolin-1-ones, 2-allyl-3-benzyl-3-hydroxy- and 2,3-dibenzyl-3-hydroxyisoindolin-1-ones were formed when boiling benzylidenephthalide and amine at 56–70°C. An increase in the reaction temperature leads to the splitting off of the 3-hydroxyl group and the formation of either only the cis- and trans-isomers of N-substituted 3-benzylidenephthalide or a mixture of them with an admixture of 3-hydroxy precursor depending on the nature of the amine component and the boiling duration. In contrast, cis-N-substituted 3-benzylidenephthalide was predominantly formed when the 3-hydroxy precursor was treated with trifluoroacetic acid at room temperature. During acylation of the 3-hydroxy-2-(2-hydroxyethyl) precursor with acetic or 3-chlorobenzoic acid halides, along with esterification at the primary hydroxyl, a water molecule was also eliminated to form a mixture of (Z)- and (E)-3-benzylidene-N-[2-(2-acetoxyethyl- or -N-[2-(3-chlorobenzoyloxy)ethyl]isondolin-1-ones with a significant predominance of the (Z)-isomer. During esterification of this precursor with 3-chlorobenzoic acid under similar conditions, the 3-hydroxyl group is retained. The resulting compounds were studied as fungicides against the microscopic fungi Bipolaris sorokiniana, Fusarium oxysporum, and Rhizoctonia solani. All the tested compounds exhibited fungicidal activity against Rhizoctonia solani.

Biodiesel, a renewable and biodegradable fuel, offers significant environmental advantages but faces challenges such as lower combustion efficiency and increased nitrogen oxide (NO_x) emissions compared to diesel. Addressing these limitations requires innovative material-based approaches. This study explores the combined effects of nanoparticle-enhanced biodiesel and Fe/Zn-coated catalytic converters on engine performance and emissions, addressing a gap in understanding the synergistic potential of these materials. The objective was to assess how cerium oxide (CeO₂) and zinc oxide (ZnO) nanoparticles, integrated with advanced catalytic coatings, influence combustion and emission characteristics. Using a single-cylinder diesel engine, performance metrics such as brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) were analyzed, alongside emissions of NO_x, carbon monoxide (CO), and particulate matter (PM). Results revealed significant improvements in BTE (up to 34.5%) and reductions in NO_x (15%) and PM emissions (28%) with nanoparticle-enhanced biodiesel and catalytic converters. These findings highlight the transformative potential of material innovations in sustainable energy technologies. Future research should explore the scalability and long-term environmental impacts of these materials.