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Volume 95, Nº 9–10 (2025)
Articles
Synthesis and biological activity of bis-1,3,4-oxadiazoles (a review)
Resumo
The review presents achievements in the field of synthesis and study of biological activity of various bis-1,3,4-oxadiazoles from 1999 to 2024. The methods for obtaining bis-1,3,4-oxadiazoles repeat the methods used to obtain 1,3,4-oxadiazoles and are mainly implemented due to intramolecular cyclization under the action of phosphorus oxychloride or bases. Oxidative cyclization reactions play a major role. Single examples of the application of the Huisgen reaction and an electrochemical version of cyclization are presented. The main direction of the study of biological activity is antibacterial, and studies of antifungal and anticancer activity are also presented.
Russian Journal of General Chemistry. 2025;95(9–10):357-370
357-370
Synthesis of surface-active amino alcohols containing [1,1′-bi(cyclohexane)]-1-ene fragment
Resumo
Cyclocondensation of industrially available [1,1′-bi(cyclohexane)]-1′-en-2-one (Wallach ketone) with aminoethanols under acid catalysis conditions leads to 6-(cyclohex-1-en-1-yl)-1-oxa-4-azaspiro[4.5]decanes in 56–88% yields. A series of ethanolamines (yields 73–96%) containing a hydrophobic [1,1′-bi(cyclohexane)]-1-ene fragment were obtained by reductive cleavage of these 1,3-oxazolidine derivatives under the action of NaBH4. The synthesized amino alcohols have surface activity and are highly effective inhibitors of hydrochloric acid corrosion of carbon steel with a protective effect of up to 98.1%.
Russian Journal of General Chemistry. 2025;95(9–10):371-376
371-376
Synthesis of 6-aryl-2-(2,6-dimethylphenyl)-3-imino-3,5-dihydro-1h-pyrrolo[3,4-c]pyridine-1,4(2h)-diones
Resumo
6-Aryl-2-(2,6-dimethylphenyl)-3-imino-3,5-dihydro-1H-pyrrol[3,4-c]pyridine-1,4(2H)-diones were obtained by the reaction of N-2,6-dimethylphenylamides of 4-aryl-2-hydroxy-4-oxo-2-butenoic acids with cyanoacetamide in ethanol or propan-2-ol. Structure of the obtained compounds was confirmed by IR, 1H and 13C NMR spectroscopy, and single crystal X-ray diffraction analysis.
Russian Journal of General Chemistry. 2025;95(9–10):377-383
377-383
Synthesis of Novel N-Hydroxybenzoyl Derivatives of 5-Methyl-1,2-Oxazole-3-Amines as Potential Antiglycation Agents
Resumo
A method was developed for a one-pot multicomponent synthesis of N-hydroxybenzoyl derivatives of 5-methyl-1,2-oxazol-3-amine by the Schotten–Baumann reaction (Einhorn method) by carrying out successive reactions without isolating intermediate products: the reaction of chlorides of hydroxybenzoic acids or their functional derivatives with aminoisoxazole at room temperature in methylene chloride at pH = 8–9. The structures of the obtained compounds were confirmed by 1H and 13C NMR spectroscopy data. Significant antiglycation activity of some target compounds was revealed in vitro testing.
Russian Journal of General Chemistry. 2025;95(9–10):384-394
384-394
Dyes for photoelectronics based on (12H-quinoxalino[2,3-B]phenoxazinyl)phenyl derivatives
Resumo
The acylation reactions of 4-(2,4-di-tert-butyl-10-methoxy-12H-quinoxalino[2,3-b]phenoxazin-12-yl)aniline with acid chlorides of various structures, including substituents with the properties of anchor groups (hydroxyphenyl, carboxyl, acrylamide, methacrylamide), as well as isobenzofuran-1,3-dione and dihydrofuran-2,5-dione led to the formation of the corresponding 4-(2,4-di-tert-butyl-10-methoxy-12H-quinoxalino[2,3-b]phenoxazin-12-yl)anilides in high yield (79–92%). The resulting amides were characterized by strong (ε = 2.94–4.26∙104 M–1·cm–1) absorption bands in the range of 470–630 nm with maxima at 548–551 nm. They also exhibit a photovoltaic effect and high open-circuit parameters (up to 0.57 V) in DSSC solar cells and the ability to exhibit photodiode properties.
Russian Journal of General Chemistry. 2025;95(9–10):395-405
395-405
Synthesis of organosilicon salts based on 2-aminobenzimidazolium cation
Resumo
Unknown organosilicon iodides based on 2-aminobenzimidazolium cation were obtained in a one step by solvent- and base-free silylalkylation of 2-aminobenzimidazole with mono- and bis(iodomethyl)derivatives of silanes and siloxanes. 2-Aminobenzimidazolium nitrates containing silicon atoms in the molecule were synthesized through the anion exchange in the above organosilicon iodides.
Russian Journal of General Chemistry. 2025;95(9–10):406-415
406-415
N-[Dimethyl(chloromethyl)silyl]amides of Chloroacetic Acids: Synthesis and Structure
Resumo
N-[Dimethyl(chloromethyl)silyl]amides of chloroacetic acids were synthesized by the reaction of amides of mono-, di-, and trichloroacetic acids with bifunctional silane ClCH2SiMe2Cl in hexane or benzene in the presence of a base. Their structure was confirmed by multinuclear NMR spectroscopy using 1H, 13C, 29Si, and 15N nuclei.
Russian Journal of General Chemistry. 2025;95(9–10):416-422
416-422
Structure and Properties of Germanium [n]-Prismanes Ge2nH2n: A Quantum Chemical Study
Resumo
Using the B3LYP/6-311+G(df,p) method, the stability limits of germanium prismanes Ge2nH2n were studied and it was shown that the prismane configurations are stable up to n = 15, while with a further increase in n, a distortion of the prismatic structure is observed. The greatest stability is demonstrated by 5-germaprismane Ge10H10, while the remaining members of the series show a progressive decrease in stability with increasing n. Germanium systems are characterized by lower stress energy, lower binding energy, and lower formation enthalpy compared to carbon and silicon systems, with the trends in the main characteristics corresponding to those observed for carbon and silicon derivatives.
Russian Journal of General Chemistry. 2025;95(9–10):423-433
423-433
Synthesis and spectral fluorescence properties of Mg(II)-porphyrins
Resumo
Mg(II)-5,15-diphenylporphyrin, Mg(II)-5,10,15,20-tetraphenylporphyrin, Mg(II)-2,3,7,8,12,12,13,17,18-octaethylporphyrin and Mg(II)-5,10,15,20-tetra-(pentafluorophenyl)porphyrin were obtained using the coordination reaction of the corresponding porphyrins with magnesium acetate in a boiling dimethylformamide–ethylene glycol mixture. The complexation of β-octachloro-5,10,15,20-tetra(pentafluorophenyl)porphyrin with magnesium acetate in dimethylformamide already at room temperature led to the formation of the corresponding Mg(II)-porphyrinate. A facile method for the preparation of magnesium complexes with magnesium chloride in dimethylformamide has been proposed as an example of the metal exchange reaction of Cd(II)-5,10,15,20-tetraphenylporphyrin and Cd(II)-2,3,7,8,12,13,17,18-octaethylporphyrin. The synthesized compounds were identified by UV-Vis, NMR spectroscopy,mass spectrometry and elemental analysis methods. The fluorescence properties of Mg-porphyrins in acetone have been studied. The values of fluorescence quantum yields and Stokes shifts of the studied compounds were calculated. The influence of the nature of substituents on the fluorescence characteristics of Mg-porphyrins was evaluated. The coordination reaction of β-octachloro-5,10,15,20-tetra(pentafluorophenyl)porphyrin with magnesium acetate in dimethylformamide was studied by spectrophotometric method. The kinetic parameters were calculated and the stoichiometric mechanism of the studied reaction has been proposed.
Russian Journal of General Chemistry. 2025;95(9–10):434-445
434-445
Acetone Acylhydrazones as Reagents for Flotation Concentration of Non-Ferrous Metal Ions
Resumo
The interaction regularities of reagents acetone acylhydrazones series with Cu(II), Ni(II) and Co(II) ions in precipitation and precipitate flotation processes were studied. The composition of the formed complexes precipitates was established; their solubility product values were calculated. The flotation kinetics has been described using the classical first-order model. An assumption about the composition of the floated compounds was made. The possibility of metal ions recovery up to 98–99%, as well as selective separation of Cu(II) ions, was shown.
Russian Journal of General Chemistry. 2025;95(9–10):446-455
446-455
Determination of the Charge State of Transition Metal Ions in Pyrochlore Bi2Cu1/3Ni1/3Co1/3Ta2O9±δ by X-Ray Absorption Spectroscopy
Resumo
Cubic pyrochlore Bi2Cu1/3Ni1/3Co1/3Ta2O9±δ [space group Fd-3m, a = 10.5323(8) Å] was synthesized from oxides for the first time using the solid-phase reaction method. The ceramics are characterized by a low-porosity grain-free microstructure. The chemical state of transition element cations in multi-element pyrochlore was characterized using photoelectron spectroscopy (XPS) and NEXAFS. For pyrochlore, a characteristic shift of the Ta4f spectrum to lower energies by 0.65 eV is observed, which causes the effective charge of tantalum cations +(5–δ). It is shown that the NEXAFS Cu2p spectra of oxide ceramics, according to the main characteristics of the spectrum, represent a superposition of the spectra of Cu(I) and Cu(II) cations. Based on the analysis of the relative intensity of the peaks in the XPS spectrum of Cu2p, the quantitative ratio of Cu(I)/Cu(II) cations in pyrochlore is 1.06. The NEXAFS Ni2p spectrum of ceramics coincides with the spectrum of NiO according to the main characteristics of the spectrum. XPS studies indicate the state of Ni(III). According to the nature of the Co2p spectrum, cobalt ions are in the state of Co(II,III).
Russian Journal of General Chemistry. 2025;95(9–10):456-464
456-464
Effect of Coordination Environment on Luminescence of Crystalline Cerium Halides
Resumo
The effect of the coordination environment on the photoluminescence of crystalline cerium trihalides CeL3 (L = F, Cl, Br, I) was investigated. It was found that in the series of anions F– > Cl– > Br– > I– a bathochromic shift of luminescence maxima is observed, which is correlated with an increase in the degree of Ce–L bond covalency and anion polarisability. Using PBE/3ζ density functional theory and classical Pauling’s approach, calculations of anion polarisability and Ce–L bonding parameters were carried out, revealing a direct correlation between these values and the long-wavelength shift of maxima. This fact allows us to postulate that the bathochromic shift of maxima in the photoluminescence and photoluminescence excitation spectra of solid CeL3 is due to the nepheloxetic effect, namely, an increase in the degree of covalency of the Ce–L bond, leading to a decrease in the energy gap between the valence zone (np-levels of L–) and the conduction zone (5d-levels of Ce3+). The results demonstrate the possibility of controlling the spectral characteristics of the luminescence of Ce3+ compounds by changing the coordination environment, which is important for the development of new cerium-containing luminophores.
Russian Journal of General Chemistry. 2025;95(9–10):465-471
465-471
Synthesis and Study of Iron-Graphene Composites
Resumo
Iron-graphene composites were synthesized by heat treatment of a mixture of iron (III) nitrate and graphite oxide in an argon flow, followed by reduction in a hydrogen flow. The composites were characterized by elemental analysis, thermogravimetry, scanning electron microscopy with energy-dispersive X-ray spectra and construction of maps of the spatial distribution of components, X-ray phase analysis, and Mössbauer spectroscopy. It was shown that the synthesized composites are sheets of a graphene-like material with iron-containing nanoparticles deposited on them, the size of which depends on the concentration of the iron compound in the original mixture. Iron nanoparticles in the obtained composites are rapidly oxidized upon short-term contact with air and can be restored by cyclic treatment at 400°C, including vacuuming the composite followed by exposure to hydrogen under pressure.
Russian Journal of General Chemistry. 2025;95(9–10):472-480
472-480
Modification of urethane hot-melt adhesives used for the production of rubber composites
Resumo
Currently, polyurethane hot-melt adhesives based on urethane prepolymers containing terminal isocyanate groups are predominantly used as binders for rubber crumb. In this study, urethane prepolymers were synthesized using polypropylene oxide with a molecular weight of 2000 and polyisocyanates of both aromatic and aliphatic nature. The urethane prepolymers were modified using a metal-complex system, leading to the structuring of the polyurethane binders. As a result, a twofold increase in the strength and elasticity of the polyurethanes was achieved, along with improved heat resistance.
Russian Journal of General Chemistry. 2025;95(9–10):481-488
481-488