Chemical Bulletin of Kazakh National University
Chemical Bulletin of Kazakh National University (ISSN 1563-0331, eISSN 2312-7554, abbreviated title: Chem. Bull. Kaz. Nat. Univ.) is the open-access journal publishing high-quality original scientific articles since 1992 (four issues per year). The Bulletin covers all areas of chemistry including the multidisciplinary chemistry. The journal aims to become international. It has the international Editorial Board and is open to authors from all around the world. Advantages of publication in our Journal: indexing in many databases (CAS, CrossRef, Web of Science) simplifies finding your article free access to full text of your article (higher number of readers = more citations and higher h-index) peer-review of the article by qualified experts improves it's overall quality and increases the probability of application of your results by other scientists quick publication rates - article appears online with DOI one week after acceptance, final publication with numbers of issue and pages in 2 weeks (average). Total time after submission to publication - 10 weeks continuous and active work of the Editorial team on the increase of the quality and the ranking of the Journal
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A comprehensive investigation of multilayer Ti₃C₂Tₓ MXene for supercapacitors in alkaline and acidic media
Multilayer Ti3С2Tx MXene was synthesized from Ti3AlC2 MAX phase via hydrofluoric acid etching followed by a gentle shaking-assisted delamination strategy, yielding well-preserved layered structures with expanded interlayer spacing of ~1.2–1.3 nm. Structural and spectroscopic analyses confirmed effective removal of Al layers and the formation of functionalized accordion-like MXene sheets. The electrochemical behavior was systematically investigated in symmetric two-electrode cells using alkaline and acidic electrolytes. The MXene electrode exhibited quasi-rectangular CV curves and symmetric charge–discharge profiles in alkaline media, indicating predominantly capacitive charge storage with good reversibility and rate capability. Significantly higher capacitance and improved retention were obtained in 6 M KOH, reaching ~70–72 F g-1 at low scan rates, which is attributed to enhanced ionic conductivity, reduced charge-transfer resistance, and faster ion diffusion, as further supported by EIS analysis. In contrast, the acidic electrolyte showed distorted CV responses and increased polarization, suggesting slower charge-transfer kinetics and diffusion limitations. These findings highlight the decisive role of electrolyte chemistry in governing charge-storage mechanisms and demonstrate the strong potential of multilayer Ti3С2Tx MXene for supercapacitor applications in concentrated alkaline electrolytes.
Copyright (c) 2026 Zh.A. Supiyeva, A.B. Tugelbayeva, B. Balgabayeva, F. Sultanov https://creativecommons.org/licenses/by-nc-nd/4.0
Effect of dibenzothiophene on the hydrogenation of aromatic hydrocarbons over mesoporous materials
This study investigates the effect of dibenzothiophene on the hydrogenation of aromatic hydrocarbons over bifunctional catalysts based on mesoporous Al-HMS aluminosilicates. Mesoporous aluminosilicate materials with different Si/Al ratios varying from 10 to 70 were synthesized and employed as supports for Ni-Mo-Al-HMS-H-bentonite catalysts. The physico-chemical features of the materials were characterized using ICP-OES, nitrogen physisorption at low temperatures, XRD, FTIR, and pyridine adsorption FTIR spectroscopy. Catalytic activity was evaluated in the hydrogenation of a model mixture of 2-methylnaphthalene and n-hexadecane at temperatures between 220-300°C and at 6 MPa H2. The optimal catalytic performance was observed for the sample with a Si/Al ratio of 10, displaying high conversion and selectivity to 2-methyldecalin as a result of sufficient Brønsted and Lewis acidity. The presence of dibenzothiophene leads to a decrease in conversion and selectivity due to sulfur-induced catalyst poisoning and shifts the optimal reaction temperature from 240 to 260°C. These findings highlight the important role of acid properties of mesoporous aluminosilicates in hydrogenation and hydrotreatment processes of aromatic compounds.
Copyright (c) 2026 A. Abdrassilova, G. Vassilina, K. Abdildina, T. Abildin https://creativecommons.org/licenses/by-nc-nd/4.0
Determination of the chemical composition of liquid products of thermocatalytic cracking of hydrocarbon mixtures
This study presents the results of a comprehensive experimental investigation of the co-pyrolysis processes of carbon-containing wastes of various origins, including coal dust from the Kulan deposit, plastic waste based on polyethylene and polypropylene, gossypol resin isolated from soapstock generated during cottonseed oil production, and oil sludge from the “Petro Kazakhstan Oil Products” refinery (Shymkent). The experiments were carried out over a wide temperature range of 500–700 °C at atmospheric pressure in inert (N₂) and weakly acidic (CO₂) gas atmospheres. Fractional separation and identification of the components of the liquid pyrolysis products were performed using extraction methods. It was established that the nature of the gas medium and the process temperature exert a decisive influence on the yield and distribution of oil, resin, asphaltene fractions, and insoluble substances. It was shown that the thermocatalytic cracking of individual wastes and their mixtures (1:1:1:1) results in the formation of a liquid product dominated by oils and resins with a reduced asphaltene content. A pronounced synergistic effect of co-pyrolysis was identified, associated with the destruction of polyphenolic structures and fatty acids of gossypol resin, leading to hydrogen formation that contributes to the stabilization of active hydrocarbon radicals generated during the thermal decomposition of coal dust and polymer waste. This promotes the intensification of secondary synthesis reactions with the formation of olefins, aromatic hydrocarbons, and resinous compounds, as well as a redistribution of the fractional composition of liquid products toward an increased oil fraction at elevated temperatures. Gas chromatography–mass spectrometry analysis demonstrated that co-pyrolysis of the multicomponent mixture ensures the formation of hydrocarbon products with a uniform distribution across the main classes of compounds, confirming the potential of this approach for the integrated processing of heterogeneous carbon-containing wastes.
Copyright (c) 2026 Authors https://creativecommons.org/licenses/by-nc-nd/4.0
Recovery of lithium and transition metals from spent LIBs using low concentration ammonia media
The exponential growth in the consumption of lithium-ion batteries (LIBs) necessitates the development of environmentally benign recycling technologies to address the impending surge in end-of-life waste. This study presents a novel, sustainable hydrometallurgical approach for the recovery of critical metals (Li, Ni, Co) from spent NMC/LCO cathode materials utilizing a low-concentration ammonia system. In contrast to conventional methods relying on high ammonia concentrations (4-6 M), this work demonstrates efficient metal leaching using only 0.5 M NH4OH buffered with ammonium sulfate, employing sodium sulfite (Na2SO3) as a reducing agent to facilitate the breakdown of the oxide matrix. Through systematic optimization, the optimal process parameters were established: 0.5 M NH4OH, 0.273 M (NH4)2SO4, and 0.8 M Na2SO3 at pH 10.5 and 80 °C. Under these conditions, the system achieved leaching efficiencies of 99.6% for Ni, 96.4% for Li, and 89.1% for Co. A distinctive feature of the developed process is the selective retention of manganese; unlike acid leaching, this method retains 76% of manganese in the solid residue, significantly simplifying downstream purification and target component separation. The proposed method offers an eight-fold reduction in ammonia consumption compared to conventional ammoniacal schemes, substantially lowering both operational costs and the carbon footprint of the recycling process.
Copyright (c) 2026 Artur Grigoryev, Saken Abdimomyn, Mikhail Simonov, Fyodor Malchik https://creativecommons.org/licenses/by-nc-nd/4.0
Impedance spectroscopy diagnostics of spent lithium-ion batteries in recycling processes
The widespread adoption of electric transportation is leading to the accumulation of spent lithium-ion batteries requiring sorting prior to recycling or reuse. Effective triage of end-of-life (EoL) batteries necessitates rapid non-destructive diagnostic methods capable of assessing the state of health at the individual cell level. This study proposes an approach to rapid diagnostics based on electrochemical impedance spectroscopy. Using a 10S6P battery pack from an electric scooter operated under sharply continental climate conditions as an example, we demonstrate that equivalent circuit model parameters – including ohmic resistance, charge transfer resistance, and constant phase element exponents – enable the identification of intra-pack degradation heterogeneity and classification of cells according to their suitability for reuse. Analysis revealed two distinct degradation patterns: localized critical discharge attributed to battery management system malfunction, and a gradient of accelerated aging in peripheral cells due to thermocyclic stress. It was established that 80% of the cells in the investigated pack retain characteristics permitting second-life applications, while 10% exhibit signs of irreversible degradation and require immediate recycling. The results confirm the promise of impedance spectroscopy as a tool for high-throughput triage of EoL batteries within the circular economy framework.
Copyright (c) 2025 Authors https://creativecommons.org/licenses/by-nc-nd/4.0
Voltammetric study of antioxidant activity of the extract Thymus crebrifolius Klok.
Oxidative processes in the body are one of the main mechanisms of oxidative stress syndrome. Active oxygen species play a decisive role in the development of free radical pathologies, which are accompanied by lipid peroxidation, mutagenic changes in proteins and cellular metabolism disorders. It is of interest to study the antioxidant activity of the dry extract of Thymus crebrifolius Klok. in comparison with ascorbic acid using the voltammetry method. It was shown that the extract of Thymus crebrifolius Klok. exhibited an antioxidant activity coefficient equal to 1,36 ± 0,06, calculated on the basis of the change in the reduction current compared to the control solution. The study used a 40% aqueous-alcoholic solution of the extract of Thymus crebrifolius obtained by ultrasonic extraction. Extraction was carried out from the upper part of the plant (leaves, young shoots, flowers) at room temperature, 40 kHz twice for 30 minutes. The obtained data indicate the presence of pronounced antioxidant activity in the thyme extract, which is confirmed by its electrochemical reaction to reduction. However, compared to ascorbic acid, the activity was lower, which is probably due to a lower concentration of phenolic compounds or a more complex matrix of the extract.
Copyright (c) 2026 A.M. Akhmetalimova, S.K. Kabieva, G.N. Musina, G.A. Erkinova, R.K. Zhaslan, D.K. Kuandykov, E.V. Sitdikova, F.B. Khamkhoeva https://creativecommons.org/licenses/by-nc-nd/4.0
Catalytic destruction of a model polyaromatic system (benzothiophene–phenanthrene) using a polymeric hydrogen donor
The study investigates the effect of catalytic additives containing iron and titanium, derived from converter shop slag of Qarmet JSC, on the thermal destruction of a model mixture. A polymeric material, polyethylene, was used as a hydrogen donor. The thermal decomposition of a mixture consisting of phenanthrene and benzothiophene, in the presence of polyethylene and iron- and titanium-based catalytic additives, was examined using thermogravimetric analysis. It is shown that the decomposition of these organic systems, modeled using the Coats–Redfern method, reliably reflects their thermokinetic behavior and provides consistent results under statistical processing of experimental data. Catalytic additives exert a significant influence on the kinetics of thermal decomposition and degradation processes in the studied systems. It is demonstrated that the titanium-containing catalyst promotes a noticeable reduction in the reaction energy barrier and activation energy, whereas the iron-containing catalyst ensures high reproducibility and stability of the kinetic parameters. The applicability of the D3 model (three-dimensional diffusion) for the accurate description of the thermodestruction process has been established, and the reliability of the Monte Carlo method has been confirmed when accounting for experimental fluctuations. Additionally, it has been established that the introduction of catalysts substantially alters the degradation kinetics: the titanium-containing catalyst leads to a decrease in activation energy, while the iron-containing catalyst ensures maximum reproducibility of the determined kinetic parameters across a series of independent experiments.
Copyright (c) 2026 A. Tusipkhan, K.K. Yessenbayeva, A.Zh. Sarsenbekova, Z.B. Akanova, N.Zh. Balpanova, M.I. Baikenov https://creativecommons.org/licenses/by-nc-nd/4.0
New glycerol-based deep eutectic solvents as green extragents for diesel fuel
The dearomatization, denitrification and oxidative desulfurization of commercial diesel fuels were investigated using glycerol-based deep eutectic solvents. The optimal conditions of liquid-liquid extraction processes were chosen as room and 90°C temperatures and 3 hours of mixing time. Ammonium chloride-glycerol, triethylammonium acetate-glycerol and choline chloride-glycerol were used as extractive solvents in the purification processes. Diesel-Deep eutectic solvents (Diesel-DESs) were taken as the volume ratios of 1:1 for the dearomatization and denitrification processes. The volume ratios of Diesel-DESs-H2O2 were 1:1:2 for the oxidative desulfurization. H2O2 was selected as the oxidative agent of oxidation desulfurization. Before and after separation processes, the exploitation properties were studied by ASTM standards and compared to commercial diesel. All separation processes were controlled by gas chromatography and 1H NMR methods. Based on the NMR analysis, NH4Cl/6Glycerol with H₂O₂ and ChCl/6Glycerol were the most effective extractive agents for purified diesel samples, from the alkyl aromatic, naphthenic, and heteroatomic compounds.
Synthesis and X-ray examination of neodymium and magnesium double nickel-manganite NdMg2NiMnO6
Manganites-perovskites are an important class of materials with unique physical properties such as tremendous magnetoresistance and magnetocaloric effect. They have a perovskite structure and can be described by the general formula AMnO₃, where A is a rare earth or alkali metal and Mn is manganese. The introduction of dopants into the composition of rare-earth element manganite can serve as an effective way to improve the properties of semiconductors. The aim of this work is the synthesis and X-ray diffraction study of a new nickelite-manganite of neodymium and magnesium of the composition NdMg2NiMnO6. A new nickelite-manganite of neodymium and magnesium composition NdMg2NiMnO6 was synthesized by the method of ceramic technology. The identification was carried out by XRD method. On the basis of indication it was found that NdMg2NiMnO6 crystallizes in cubic syngony with the following lattice parameters: a=10.056 ± 0.067 Å; Z=4; Vo=4139.39 ± 0.20 Å3; Vounit cell.=1034.85 ± 0.02 Å3, rх-ray.=2.5824; rpycn. =2.4970 ± 0.052 g/cm3. The tolerance factor t=0.90, which is a criterion of structure stability, was calculated. IR spectra of the investigated nickelite-manganite were obtained. The obtained results are of interest for further work on the study of thermodynamic, electrophysical properties of this compound and can be used in inorganic materials science to obtain similar substances with promising physical and chemical properties, and as initial information arrays for loading into fundamental data banks on X-ray characteristics.
Study of the physico-chemical properties of sorbents obtained by the activation of coke fines in a carbon dioxide atmosphere
The possibility of obtaining activated carbons from low-liquid fractions of carbonized materials from the coke chemical production of JSC "Shubarkol Komir" (Karaganda) has been studied. To obtain a coal sorbent, coke fines with a size of less than 10 mm were crushed and sieved to obtain a fraction of 2-5 mm. The resulting fraction was activated on a pilot plant in the presence of carbon dioxide at temperatures of 700-900°C and an activation time of 60-180 min. It was found that the maximum sorption capacity is achieved at a temperature of 800°C and an activation time of 180 min. Under these conditions, the maximum sorption capacity for iodine (56.73%) and methylene blue (100 mg/g) is achieved. Using the method of low-temperature nitrogen adsorption using the BET method, the specific surface area of the sorbent was determined, which was 446.8±4.4 m2/g. The analysis of the adsorption and desorption branches of the isotherm indicated the mesoporous structure of the obtained sorbents. The study of the exhaust gas composition showed the presence of hydrogen, carbon monoxide, carbon dioxide and nitrogen. An analysis of the gas composition of the waste activation products revealed a significant CO content (51.52%), which indicates a deep thermal modification of coke fines during activation by carbon dioxide CO2.
Synthesis and investigation of preformed particle gels based on acrylic monomers to reduce water cut in oil wells
Oil production, which often involves the extraction of relatively large quantities of water, causes a number of environmental and mechanical problems, particularly in oil reservoirs. One way to mitigate this problem is to use polymer gels as plugging agents. This article describes a method for synthesizing acrylamide-based hydrogel particles using N,N-methylenebisacrylamide as a crosslinking agent and the addition of bentonite to prepare the hybrid composite hydrogel. FTIR spectroscopy data confirmed the formation of an acrylamide-based hydrogel. The swelling capacity of the hydrogels was studied as a function of the change in the concentration of the components contained in the composition. The swelling capacity is also estimated as a function of change in temperature, salinity and acidity of the medium. The results show that the investigated hydrogel particles exhibit remarkable swelling and have a high mechanical strength. The thermogravimetric analysis indicates stability of the hydrogel particles of up to 200℃.These particles may definitely serve as a robust sealant. They show high resistance to heat and salt exposure as well as stability in acidic and alkaline conditions. Considering physicochemical properties discussed in this paper, hydrogel particles can be utilized as a cost-effective potting agent.
Influence of partial oxidation of xanthate on flotability of gold minerals
Losses of gold minerals with fine grades remain an urgent problem of modern flotation technology. Gold minerals associated with iron sulfides (pyrite, arsenopyrite) can be extracted using sulfhydryl collectors. As it is known, the maximum flotability of iron sulfides is observed in case of simultaneous presence on their surface of both xanthate and dixanthogen. The aim of the work is to study the effect of partial oxidation of amyl potassium xanthate (AKs) on the efficiency of flotation enrichment of gold-bearing sulfide ore. Partial oxidation of potassium amyl xanthate solution using turboflotation generator is proposed to obtain a collector including xanthate and dixanthogen in its composition. Testing of collectors AKs and AKs + AKsokisil. on sulfide gold-bearing ore showed that partial oxidation of xanthate to dixanthogen improves technological indicators of flotation. Partial oxidation of xanthate allows to increase gold recovery from 83.8 to 89.3 % at reduction of gold content in flotation tailings from 0.48 to 0.32 g/t. Turboflotation generator allows to increase gold recovery from 89.2 to 91.7 % at reduction of gold content in flotation tailings from 0.31 to 0.24 g/t.
Synthesis of an interpolyelectrolyte complex from fluorescently labeled chitosan and polyacrylic acid
In this study, fluorescently labeled samples of chitosan and poly (acrylic acid) (PAA) were synthesized for the first time to investigate the penetration depth of polymers and interpolyelectrolyte complex (IPEC) into forest soil, as well as their resistance to leaching. The synthesis of fluorescently labeled polymers and IPEC was carried out by mixing aqueous solutions using fluorescein isothiocyanate (FITC) and fluoresceinamine (FA). The composition and structure of the synthesized products were identified by infrared (IR) spectroscopy. The optimal molar ratio of the resulting IPEC [Chitosan]: [PAA] = [1:9] was confirmed by gravimetric analysis. Rheoviscosimetric studies revealed pseudoplastic flow behavior for chitosan and dilatant flow for PAA and IPEC. In laboratory-scale model experiments, the mechanical strength and anti-erosion performance of soil–polymer structuring agents were evaluated. Treatment of soil with IPEC led to the formation of a protective soil–polymer film that significantly enhanced resistance to wind erosion (up to 93%) and water erosion (up to 90%), and increased the mechanical strength of soil aggregates by a factor of 13. The study demonstrates that IPEC exhibits superior leaching resistance compared to individual polymers, which is of practical importance for soil structuring and stabilization under erosion-prone conditions.
Synthesis and properties of new biologically active analogues of Kazсaine
The study focuses on the synthesis and pharmacological evaluation of novel structural analogs of the anesthetic and antiarrhythmic Kazcaine. Two new derivatives were synthesized by acylation of propylacetylene alcohol 1-(2-ethoxyethyl)-4-oxopiperidine with fluorobenzoyl chlorides. Their complexes with cyclodextrin were obtained for biological screening. The evaluation of the myelostimulating activity of these complexes revealed that one of them, specifically the 3-fluorobenzoyloxy derivative, demonstrated a pronounced myelostimulating effect, particularly with regard to the stimulation of leukopoiesis and thrombopoiesis. The compound, in complex with β-cyclodextrin, showed significant stimulation of leukocyte and platelet proliferation, with a noticeable increase in the total number of leukocytes and improvement in granulocyte and lymphocyte recovery. These results indicate that the synthesized compounds have significant potential for pharmacological use, especially for stimulating hematopoiesis and protecting against myelosuppression. In addition, quantum chemical calculations of the reactions showed that ortho- and meta-fluorobenzoyl chloride have higher reactivity, which is confirmed by the high yields of the products (94% and 89%) obtained as a result of the synthesis.
Phytochemical analysis and antibacterial activity of raspberry (Rubus idaeus) fruit extract against Gram-negative multi-drug resistant bacteria from clinical isolates
The basic therapy for microbial infections involves the application of antibiotics. However, overuse of antibiotics has become the major factor for the emergence and dissemination of multi-drug resistant strains. The purpose of our work was to study the phytochemical composition of a thick extract of raspberry fruits, as well as to investigate in vitro and in silico antibacterial activity against clinical multidrug-resistant strains of A. baumannii, P. aeruginosa, K. pneumoniae and E. cloacae. The quantification of biologically active substances (BAS) was accomplished with spectrophotometric, titrimetric and HPLC methods of analysis; antimicrobial effects were evaluated by the well diffusion method, whereas minimum inhibition concentration was determined by well plate method. The total content of phenolic compounds was 0.60 and 10.10%, organic acids – 4.60 and 1.60% for raspberry fruit thick and green tea leaf extract. The total content of anthocyanins in the raspberry fruit thick extract was 110.0 mg/100 g, where cyanidin-3-O-sophoroside was dominated (52.14±1.04 mg/100 g). Theoretical studies have shown that neither a single antibiotic nor anthocyanins are highly effective in inhibiting all antimicrobial mechanisms of resistant Gram-negative bacteria. The thick raspberry fruit extract actively inhibits all resistant strains of A. baumannii, K. pneumoniae, P. aeruginosa and E. cloacae. These findings have shown that to inhibit resistant strains of bacteria, you need to use only a complex drug or dietary supplements of raspberry together, and in turn, herbal medicines are a “lifeline” for their creation and there is a chance of old antimicrobial drugs back in life.
Thermodynamic properties of zircon-manganite Lanthanum and Lithium LaLi2 ZrMnO6
The temperature dependence of the heat capacity of lanthanum and lithium zirconmanganite LаLi2ZrMnO6 was studied by the method of experimental dynamic calorimetry in the range of 298.15- 673 K. On the curve of the dependence Ср°~f(Т) at 348 K, a λ-shaped effect was revealed, probably related to a type II phase transition. Taking into account the temperature of the phase transition, the equations of the temperature dependence of the heat capacity of zirconmanganite are derived. The calculated value of the standard heat capacity of lanthanum and lithium zircono-manganite is in satisfactory agreement with experimental data within the error limits of experimental and computational methods. The standard entropy of the investigated zircono-manganites is calculated by the method of ion increments. In the range 298.15-673 K, the temperature dependences Ср°(Т) and the thermodynamic functions S°(T), H°(T)-H°(298.15) and Fxx(Т) were calculated. According to the developed methodology, the fundamental thermodynamic constant, the standard enthalpy of formation of zircono-manganite LаLi2ZrMnO6, was calculated.
Artificial protective coatings for lithium metal anode to improve its stability
The use of lithium metal as an anode in lithium-metal batteries is desired due to its high capacity and highly negative potential but is still not achieved due to the high activity and consequent chemical and electrochemical instability of this metal. On contact with the electrolyte, a film (SEI) is formed on the lithium surface consisting of the electrolyte decomposition products. Typically, this film has a heterogeneous structure, making it unstable and it cracks during cycling, which leads to lithium local deposition in the form of outgrowths – dendrites. A short circuit can occur when the dendrites grow to the cathode, followed by a possible battery fire. To solve this problem, it was proposed to coat lithium anodes with artificial SEI with the desired properties: homogeneous structure, high ionic and low electronic conductivity, and mechanical and chemical stability. The main methods for applying such coatings are dipping, dripping, doctor blade smearing, chemical or electrochemical reaction with lithium, and techniques such as magnetron sputtering, atomic and molecular layer deposition, and plasma activation. In this review examples of artificial protective coatings of different nature on lithium, their structure and functional features are considered. The reasons for their enhancement of lithium-metal anode operation stability and the characteristics obtained as a result of anode protection by these films are also indicated. At comparison of various approaches to creation of artificial SEI the methodological problem on an estimation of their efficiency is revealed and the decision variant is offered.
Technology of production and physicochemical properties of activated carbon derived from industrial waste
This study examines the specific features of the production technology of granular activated carbon obtained from substandard fine-grained carbon fractions, which are by-products of the special coke industrial production at JSC «Shubarkol Komir.» A technological scheme was developed for producing activated carbon based on this industrial waste, including the methods and conditions for granulation, carbonization, and activation. The physicochemical properties and structural characteristics of the resulting target carbon materials were evaluated. Granular and powdered activated carbons were produced from coke fines with the following composition: 60% coke fines, 35% binder, and 5% chemical activating agent. The temperature dependencies of the activation process were determined. Using adsorption-structural analysis methods, the structure of the activated carbon was studied, revealing a well-developed porous structure that includes mesopores with slit sizes ranging from 2 to 32 nm.
New method for the synthesis of oxonium derivatives of closo-borate anions [BnHn]2-
This work investigates the reaction of tetrabutylammonium salts of [B10H10]2- and [B12H12]2- anions with tetrahydrofuran, 1,4-dioxane, and tetrahydropyran in the presence of aqueous H[BF4] and H2[SiF6] solutions. It is shown that these reactions yield mono-substituted derivatives of the closo-decaborate anion ([2-B10H9O(CH2)4]-, [2-B10H9O(CH2)4О]-, [2-B10H9O(CH2)5]-) and closo-dodecaborate anion ([B12H11O(CH2)4]-, [B12H11O(CH2)4О]-, [B12H11O(CH2)5]-) in high yields. It was proven that in the case of the [B10H10]2- anion, the reaction proceeds regioselectively, leading specifically to products with substituents in the equatorial belt of the boron cluster. The closo-dodecaborate anion derivative with an exo-polyhedral tetrahydropyran substituent was further functionalized by reaction with potassium cyanide in DMF. Studies showed that this reaction results in the opening of the cyclic substituent, forming a derivative containing a pendant cyano group attached to the boron cluster via a pentamethylene spacer. This compound can be further modified at the terminal group to obtain biologically active boron-containing derivatives, promising for use in ¹⁰B-neutron capture therapy (BNCT) of malignant tumors, as well as antimicrobial and antiviral therapy. The structures of all obtained derivatives were confirmed using a comprehensive set of modern physical and physicochemical analytical methods (elemental analysis, IR spectroscopy, multinuclear NMR spectroscopy, ESI mass spectrometry).
Using expired drotaverine for corrosion protection of steel in HCl solution
In the last two decades, the scientific literature has widely covered the use of expired medicinal preparations for anticorrosion protection of metals. The aim of this work is to study expired Drotaverine (No-shpa) as a corrosion inhibitor for St3 carbon steel in a 1 M HCl solution. Drotaverine concentrations ranged from 20-80 mg/L. Studies were conducted using gravimetry, potentiodynamic polarization, impedance spectroscopy, and scanning electron microscopy. Gravimetric studies of Drotaverine’s inhibitory effect were carried out at room temperature for 2 and 24 hours, and at 80°C for 0.5 hours, showing a protective effect (Z, %) of 72, 82, and 96%, respectively, at a concentration of 80 mg/L. The Z values calculated from polarization and impedance measurements were close to those determined gravimetrically. The surface coverage of the electrode by the inhibitor was estimated, and it was shown that Drotaverine adsorption conforms to the Langmuir isotherm. The calculated free energy of adsorption, equal to -29 kJ/mol, indicates physical adsorption of the drug on the steel surface with some contribution from chemisorption. Drotaverine causes a deceleration of both cathodic and anodic electrode reactions.
Cyanethylation of two decahydroquinolone isosters and evaluation of antibacterial properties of new β-aminonitriles
Driven by the growing threat of antimicrobial resistance, the search for novel antibacterial agents has identified decahydroquinoline derivatives as promising structural scaffolds. The aim of this work was a comparative study of the synthetic reactivity of two decahydroquinolone isomers and the subsequent antimicrobial activity of their N-cyanoethylated products. The target compounds were synthesized via an aza-Michael addition, wherein the influence of stereochemistry on reactivity was investigated, and a Cu(OAc)₂ catalyst was optimized for the sterically hindered isomer. Antimicrobial activity was assessed by the broth microdilution method, while cytotoxicity was evaluated using an MTT assay on the MDCK kidney cell line. It was established that the position of the methyl group within the decahydroquinoline core is a critical determinant of both the steric accessibility for N-cyanoethylation and the resulting biological activity. The N-(β’-cyanoethyl)-2a-methyldecahydroquinolin-4-one exhibited selective bactericidal activity against the Gram-positive strain Staphylococcus aureus (MBC = 5 mg/mL), whereas its 10-methyl substituted analogue was completely inactive. Importantly, the active compound demonstrated low cytotoxicity (CTC₅₀ > 0.8 mg/mL), indicating a favorable selectivity profile. These findings identify the 2a-methyldecahydroquinolin-4-one fragment as a promising scaffold for the rational design of new selective antibacterial agents.
Evaluation of perspectives for the synthesis of Ti3AlC2 in Kazakhstan for supercapacitor application
With the increasing demand for energy-efficient technologies, there is a growing focus on developing new materials for supercapacitors and other energy devices. MXene Ti3C2Tx is known for its unique electrochemical properties and has garnered significant interest in such applications. However, the high cost of synthesizing MXene limits its commercial viability, prompting research into cost-effective methods for synthesizing the MXene precursor, the Ti3AlC3 MAX phase. This paper presents a method for synthesizing the MAX-phase Ti3AlC2 using local raw materials from Kazakhstan Electrolysis Plant JSC and Ust-Kamenogorsk Titanium-Magnesium Plant JSC. Utilizing local resources significantly reduces production costs. The study investigates the impact of temperature conditions and excess aluminum content on MAX phase formation. Process optimization, including pressing the precursors and coating them with a layer of aluminum oxide, resulted in a Ti3AlC2 content of 91.2%. MXene Ti3C2Tx derived from the synthesized MAX phase demonstrated electrochemical performance comparable to materials prepared from commercially available MAX phases. An economic assessment revealed that the cost of synthesizing 1 gram of Ti3AlC2 from local precursors is $0.22, more than 19 times lower than similar commercial materials. These findings confirm the cost-effectiveness and competitiveness of the proposed approach, highlighting its potential to create high-performance materials suitable for advanced batteries, supercapacitors, and other energy devices.
Copyright (c) 2024 Authors https://creativecommons.org/licenses/by-nc-nd/4.0
Synthesis of donor-acceptor compounds based on azulene
At present, non-benzenoid aromatic hydrocarbons are widely used as precursors for the synthesis of new materials with useful electronic properties. In particular, the non-alternative aromatic hydrocarbon azulen with a unique dipole structure and a tendency to form stabilized radical ions should be predetermined as a building block for obtaining new π-conjugated systems with interesting optoelectronic properties. This article discusses the directed synthesis and study of optical properties of new donor-acceptor compounds based on azulene. It was shown that for the synthesis of donor-acceptor phenylketone azulenes, the reaction of directed (to positions С1 and С3) acylation with benzoyl chloride in the presence of Li2MnCl4 in tetrahydrofuran was used for the first time as a key step. It was found that push-pull phenyldicyanovinyl azulenes obtained by Knoevenagel condensation of azulenylketones with malononitrile flow easily (with an increase in the yield of end products) in the presence of pyridine in dimethyl sulfoxide. Electron UV-visible spectra of phenyldicyanovinyl azulene compounds showed strong absorption bands in the visible region (λmax = 452 and 434 nm) caused by intense intramolecular charge transfer between the donor azulene ring and the acceptor phenyldicyanovinyl group.
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In silico drug-likeness, biological activity and toxicity prediction of new 3,5-bis(hydroxymethyl)tetrahydro-4H-pyran-4-one derivatives
This paper presents the results of predicting drug-likeness, biological activity, and toxicity for 8 new derivatives of 3,5-bis(hydroxymethyl)tetrahydro-4H-pyran-4-one using bioinformatic methods. The physicochemical and pharmacokinetic parameters of the studied compounds were determined, in silico screening for biological activity and prediction of their toxicity were carried out. Physicochemical and pharmacokinetic parameters were evaluated using the Molinspiration Cheminformatics service. It was found that compounds 1–11 corresponded to Lipinski’s rule for drug-like compounds. As predicted in Molinspiration, compound 4 exhibits significant biological activity as a possible enzyme inhibitor and G-protein coupled receptor ligand. Compound 6 is active as an ion channel modulator. Virtual PASS screening identified compounds with potential antidiabetic activity (1–3, 5–8) and activity in the treatment of phobic disorders and dementias (1–5, 7, 8, 11). Compound 1 can potentially act as a substrate for CYP2H, and inhibitors of enzymes of the peptidase group are 1, 3, 4, 6, 7, 11. As a result of QSAR prediction based on LD50 values calculated in ProTox-II, compound 10 belongs to class 6; compounds 1–3, 5 and 8 belong to the 5th class of toxicity; compounds 6 and 9 belong to the 4th class. Compound 4 belongs to class 3. Compounds 1–9 do not exhibit the toxicities shown in the ProTox-II models. Compounds 10 and 11 may be carcinogenic.
Structural and mechanical properties of gelatin composite films
The deformation properties, elastic modulus and strength of gelatin films with chitosan, citric acid and L-glutamic acid were studied. According to the results of the study, it was found that the addition of chitosan, citric and L-glutamic acid increases the strength and elasticity modulus of gelatin films. Assessment of the pH effect on the gelatin - chitosan, gelatin - citric acid and gelatin - L-glutamic acid systems provide a representation of their changes in these media. It is assumed that gelatin with L-glutamic acid forms a strong structure at low pH and withstands the conditions of the acidic environment of the stomach, while in an alkaline environment the structural and mechanical characteristics of this system decrease, creating favorable conditions for the release of encapsulated insulin in the intestinal phase. The changes of the physicochemical, structural and mechanical properties of the films under simulated gastrointestinal conditions (pH = 1.0; 4.01; 6.86; 9.18) were determined by IR spectroscopy. The observability of the bands of С-Н, С-ОН, С=O, C-N, N-H, СН(NH2), CH2OH groups in the infrared spectra of films in various pH media is associated with an increase of intermolecular hydrogen bonds and the formation of associative structures.
Comparative characteristics of microcrystalline cellulose obtained from the rice waste production of Kazakhstan
Development of methods for effective processing of reconstructive biological resources and allocation of valuable materials refers to the main tasks of science and industry. The work determines the optimal hydro module and physico-chemical properties of microcrystalline cellulose (MCC), obtained by the method of organosolvent oxidation of rice husk (RH), grown in the southern (Kyzylorda region) and southeast (Almaty region) of Kazakhstan, and it was established that the yield and the qualitative indicators of the MCC depends on the climatic and geographical features of the region, where raw materials are grown to obtain cellulose. The effective hydro module for MCC obtained from Bakanas rice husk (B-RH) was found to be 1:12 g/mL and yield was 45.0%, whereas Kyzylorda rice husk (K-RH) the effective hydromodule was 1:10 g/mL and yield found to be equal to 52.58%. During organosolvent oxidation, the selected method did not require additional processing of raw materials. It was discovered that for delignification, it takes 120 minutes of time, and the yield of MCC will be 15-18% higher than the cellulose obtained by the alkali. Rice husk is a promising alternative raw material for cellulose production and the use of the organosolvent method for obtaining an MCC is an economically advantageous and environmentally friendly method.
Variations in the distribution of trace elements in pyrrhotite Fe1-xS depending on the parameters of mechanical homogenization
This paper presents the results of the synthesis of sulfide standards based on the Fe0.91S pyrrhotite matrix, including 24 elements (Co, Ni, Cu, Zn, As, Se, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, W, Re, Os, Ir, Pt, Au, Pb, Bi) intended for use in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The main attention is paid to the study of the influence of such parameters as the duration of mechanical milling, the laser beam diameter during measurements and the initial concentrations of impurities on the distribution of trace elements in the material. As a result, it was found that with 120 min of milling in combination with a laser beam of 80 μm diameter, it is possible to achieve relative standard deviation (RSD) values of 10%, which corresponds to the recommendations for most elements. At high impurity concentrations, the RSD values for most elements are lower, but the material becomes more heterogeneous. At the same time, at lower concentrations, an improvement in the homogeneity of the composition is observed. The data obtained demonstrates the effectiveness of mechanical homogenization for improving analytical accuracy and reproducibility, which makes such standards promising for the analysis of complex sulfide materials in geochemistry and materials science.
Mіnі-rеvіеw: Advаnсеs іn thе sуnthеsіs аnd bіоlоgісаl асtіvіtу оf bеnzоfurохаn аnd furохаn dеrіvаtіvеs
Benzofuroxan and furoxan derivatives are heterocyclic compounds well known for their ability to act as nitric oxide (NO) donors. Due to their NO-releasing properties, these compounds have attracted considerable attention for their antimicrobial, antiviral, and antitumor activities. Their potential use in treating cardiovascular, gastrointestinal, and neurodegenerative disorders further underscores their pharmacological relevance. Given the increasing research interest in these compounds, there is a need to consolidate recent findings related to their chemical properties and biological potential. This mini-review aims to provide an up-to-date overview of the synthetic strategies and bioactivities of benzofuroxan and furoxan derivatives. Rather than focusing on ring synthesis, this review highlights the reactivity of side-chain functional groups and the design of hybrid molecules. Representative examples of drug-like compounds are discussed, along with their biological profiles. The review also explores emerging directions in the development of novel NO donors based on these frameworks with improved pharmaceutical efficacy and controlled NO release.
Synthesis, electronic and emission spectroscopy of diphenylamine-azulene co-oligomers
New strategies for creating functional materials are of great interest for the further development of optoelectronic devices such as organic field-effect transistors (OFETs), organic light emitting diodes (OLEDs), dye-sensitized organic solar cells (DSSCs) and others. In this area, research has focused on the application of various building blocks that can fine-tune the electronic structure of materials to optimize the fabrication performance and morphology. To date, the most effective molecules as building block are aromatic hydrocarbons, for example azulenes. In this study, new conjugated diphenylamine-azulene co-oligomers with linear and branched structures were synthesized with high yields via the Suzuki–Miyaura cross-coupling reaction. The obtained co-oligomers exhibit a pronounced ability to absorb and emit visible light in the 400–700 nm range. It was demonstrated that these unique photophysical properties, particularly the intense emissions in the green and orange photoluminescence range, result from the electron-donating properties of diphenylamine groups and the expansion of π-conjugation, which significantly alters the electronic structure of azulene, including the levels and energy gaps of the frontier HOMO-LUMO orbitals. These findings provide a rational approach to designing a series of new conjugated co-oligomers based on diphenylamine-azulenes for optoelectronic and photonic devices.
Thermal treatment of model water-in-oil emulsions by coal fly ash particles
One of the primary challenges in the oil industry is the formation of stable crude oil emulsions, which cause equipment and pipeline corrosion due to the inorganic salts dissolved in the aqueous phase. This study investigated the effect of coal fly ash on model crude oil emulsions. The model emulsions were prepared using crude oil samples from the Kyzylorda and Atyrau regions. Thermal demulsification at 60°C resulted in a low dewatering rate, with only 16% of water separated from a 50% water-in-oil emulsion. Higher efficiency in oil emulsion separation was observed using the microwave treatment method. The highest dewatering degree was achieved for the Atyrau crude oil emulsion, reaching 75% after 155 seconds for a 50% emulsion with a 1% ash concentration at a microwave power of 700 W, while the dewatering for the Kyzylorda oilfield emulsion was 50% under the same conditions. This difference in demulsification efficiency is attributed to the composition of the crude oil samples. It has been demonstrated that the microwave treatment method combined with the use of coal fly ash enables the separation of water-in-oil emulsions within a short period.