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Self-diffusion micromechanism in Nafion studied by 2H NMR relaxation dispersion
Journal of Chemical Physics. 2021. Vol. 154. No. 3. Article 034904.
Galitskaya E., Privalov A., Vogel M., Ryzhkin I., Vitaly V. Sinitsyn
The Field Cycling (FC) 2H NMR relaxometry was applied to study dynamics in Nafion NR 212 in the temperature range from 300K to 190K and water content l=8.2. The sensitive time window of FC was extended up to 8 decades using temperature-frequency superposition principle and master curve. The rotational correlation times obtained from 2H FC NMR coincide with translational correlation times gained from static field 2H NMR diffusometry in temperature range applied. This fact means that a long-range mass transport in Nafion is coupled to molecular rotations. It is assumed that confined water in Nafion has more ordered oxygen sublattice as compared with bulk water, on a short range is similar to ice. We discuss the possible role of D and the L defects, typical for ordered ice structure and using this concept to describe the processes of self-diffusion of confined water in Nafion, as well as similarity of temperature and humidity dependence of self-diffusion and proton conductivity.
Мальцева В. Е., Ananyev I., Sivaev I. et al., Journal of Cluster Science 2025 Vol. 36 No. 5 Article 161
The conformational mobility of the [8-EtO-8’-I-3,3’-Co(1,2-C2B9H10)2]− anion, which has been chosen as a model compound for many potential drugs based on cobalt bis(dicarbollide), was studied by 1H NMR spectroscopy, single crystal X-ray diffraction and quantum chemical calculations. According to the results of quantum chemical calculations, the most favourable conformation for [8-EtO-8’-I-3,3’-Co(1,2-C2B9H10)2]− is the transoid conformation, which is stabilized by one ...
Added: May 13, 2026
Мальцева В. Е., Оскорбин А. А., Журнал общей химии 2023 Т. 93 № 11 С. 1722–1735
С использованием композитных методов квантово-химических расчетов и метода атомизации выполнены расчеты энтальпии образования для тестового набора из 79 соединений с точностью 3.8, 4.5, 4.7 кДж/моль для методов G4, G4MP2, CBS-QB3 соответственно. По результатам статистического анализа отклонений теоретических значений от экспериментальных выявлено присутствие ошибок, возникающих на этапе оптимизации геометрии из-за неучтенных в расчете корреляционных эффектов. Для ...
Added: May 13, 2026
Мальцева В. Е., Ananyev I., Милевская А. В. et al., Теоретические основы химической технологии 2025 Т. 59 № 3 С. 13–22
Проведено квантово-химическое моделирование механизма экстракции Fe(III) из солянокислого раствора с использованием гидрофобных эвтектических растворителей на основе 1-октанола. Установлено, что путь реакции существенно различается в зависимости от того, является ли инертный компонент донором или акцептором водородной связи в димере с октанолом. На основе оценки прочности водородных связей показано, что более слабое взаимодействие между компонентами упрощает протекание ...
Added: May 13, 2026
Мальцева В. Е., Ananyev I., Kozhevnikova A. et al., Molecules 2024 Vol. 29 No. 21 Article 5022
A new approach to managing the extraction properties of eutectic solvents based on aliphatic alcohols is proposed. Aliphatic alcohols, when functioning as hydrogen bond donors within a eutectic solvent, significantly enhance the solvent’s efficiency in extracting metal ions. Conversely, when the alcohol acts as a hydrogen bond acceptor, its extraction properties diminish. Molecular modelling reveals ...
Added: May 13, 2026
Садртдинова Г. И., Nifantiev I., Vinogradov A. et al., Russian Chemical Reviews 2025 Vol. 94 No. 9 P. 1 – 55
The reactivity of polar vinyl monomers, unsaturated compounds containing functional groups, depends on the presence or absence of conjugation between the C=C bond and the neighbouring unsaturated moieties or donor heteroatoms. Conjugated polar vinyl monomers (acrylates, vinyl ethers, etc.) (co)polymerize upon free-radical initiation. The reaction is widely used to produce numerous polymer materials that qualitatively differ ...
Added: May 12, 2026
Ilya Nifant’ev, Komarov P., Guzelia Sadrtdinova et al., Polymers 2024 Vol. 16 No. 5 Article 681
Silica-supported chromium oxide catalysts, also named Phillips chromium catalysts (PCCs), provide more than half of the world’s production of high- and medium-density polyethylenes. PCCs are usually prepared in the Cr(VI)/SiO2 form, which is subjected to reductive activation. It has been explicitly proven that CO reduces Cr(VI) to Cr(II) species that initiate ethylene polymerization; ethylene activates ...
Added: May 12, 2026
Bisnovatyi-Kogan G., Kondratyev I., Moiseenko S. G., International Journal of Modern Physics A 2025 Vol. 40 No. 7 Article 2550018
Bright transient objects in different wave bands have been discovered in recent years.
To explain these short (from ms to s), and very powerful events, different models, galactic and
extragalactic, have been considered. One of the popular models is based on the suggestion of
transformation of the magnetized plasma blob, presumably a magnetohydrodynamic (MHD)
shock wave, moving with relativistic ...
Added: May 11, 2026
Торопина О. Д., Бисноватый-Коган Г. С., Moiseenko S. G., Astronomy Reports 2025 Vol. 69 No. Suppl. 1 P. 80–90
The results of MHD simulations of supersonic astrophysical and laboratory jets in an external
poloidal magnetic field (Br,Bz) taking into account the rotation of the matter, are presented. The ejected
matter is collimated by the magnetic field, the degree of collimation and the flow structure depend on the
relation between of the magnetic field induction and the angular ...
Added: May 11, 2026
Гущина В. А., Russian Journal of Inorganic Chemistry 2024 Vol. 69 No. 6 P. 940–948
Currently, ABX3 nanoparticles (NPs) based on lead halides attract the attention due to their unique optical properties and a wide range of applications. The preparation of NPs with lead as a partial or complete replacement is particularly interesting because of the toxicity of this chemical element and most of its compounds. In this study, we propose a ...
Added: May 6, 2026
Morozov E. V., Demin A. S., Borovitskaya I. V. et al., Inorganic Materials: Applied Research 2026 Vol. 17 No. 3 P. 619–626
This article presents the results of experiments on the impact of powerful pulsed ion-plasma and
electron flows generated in the working chamber of the Plasma Focus PF-5M installation during each highvoltage
discharge on a model aluminum alloy B95. It is shown that the general characteristics of the alloy’s
damage upon exposure to pulsed flows of helium ions (HI) ...
Added: May 4, 2026
A. A. Ponomarev, N. L. Aleksandrov, Plasma Physics Reports 2026 Vol. 52 No. 3 P. 367–378
An approximate method for calculating drift velocity and other kinetic coefficients of heavy ions
in a light gas is generalized to gaseous mixtures. Obtained equations are used to calculate the mobilities of
and ions, as well as rate constants for inelastic ion–molecule processes with these ions in helium with
small additions of O2 under an electric field. Calculated ...
Added: April 27, 2026
Domrin V. I., Malova H. V., V. Yu. Popov et al., Cosmic Research 2026 Vol. 64 No. 2 P. 238–252
During magnetospheric perturbations a relatively thin current sheet with thickness about several
proton gyroradii forms in the Earth’s magnetotail. In a framework of the kinetic model describing current
sheet thinning in the magnetotail, the processes of its formation are investigated depending on the normal
magnetic field magnitude which affects both the current sheet structure and particle dynamics within ...
Added: April 27, 2026
Tsareva O. O., Malova H. V., V. Yu. Popov et al., Plasma Physics Reports 2026 Vol. 52 No. 2 P. 179–185
The influence of asymmetry of plasma sources on the structure and spatial localization of a superthin
current sheet (STCS) supported by demagnetized electrons is studied using a self-consistent model. The
simulation takes into account the presence of a single plasma source in the northern hemisphere, which
makes the plasma flow asymmetric. It is demonstrated that the asymmetry of ...
Added: April 27, 2026
П.А.Беспалов, О.Н. Савина, Геомагнетизм и аэрономия 2025 Т. 65 № 5 С. 620–628
Several basic models of frequency dynamics in quasi-periodic VLF emissions with spectral form repetition
periods from 10 to 300 s are considered. In all cases, we are talking about manifestations of cyclotron instability
of electron radiation belts thet are well described within the framework of the plasma magnetospheric maser
theory based an the averaged self-consistent system of quasi-linear ...
Added: April 25, 2026
Bondarenko G.G., Fisher M. R., Kristya V. I., Bulletin of the Russian Academy of Sciences: Physics 2026 Vol. 90 No. 4 P. 572–576
A model of the cathode layer of a glow gas discharge with a thin dielectric film on a fraction of the
cathode’s working surface is formulated. It is shown that a glow discharge most rapidly transits to an arc discharge,
accompanied by a significant increase in discharge current density and a decrease in cathode voltage
drop, if the ...
Added: April 25, 2026
Krasnov L., Malikov D., Kiseleva M. et al., Journal of Medicinal Chemistry 2026 Vol. 69 No. 8 P. 8838–8851
In this work, we developed a straightforward data-driven approach to predict the cytotoxicity of metal complexes based entirely on their (metal + ligands) composition. To this end, we have manually curated MetalCytoToxDB─a comprehensive experimental database comprising 26,500 IC50 values for 7050 metal complexes against 754 cell lines from 1921 articles. Based on these, machine learning ...
Added: April 23, 2026
Magnetic properties of LiCu3O3: A quasi-two-dimensional antiferromagnet on a depleted square lattice
Bush A. A., S. K. Gotovko, Ivanov V. Y. et al., Physical Review B: Condensed Matter and Materials Physics 2024 Vol. 109 No. 11 Article 115151
LiCu3O3 is a novel two-dimensional S=1/2 antiferromagnet with randomly depleted square lattice. The crystal structure contains two types of square planes with different Cu2+→Li+ substitution rates (20% and 40%). 7Li NMR and magnetization measurements performed on single crystals of LiCu3O3 revealed the occurrence of magnetic order at Tc1=123K and the change of the magnetic state ...
Added: March 27, 2024
Panina I., Balandin S., Tsarev A. et al., International Journal of Molecular Sciences 2023 Vol. 24 No. 2 P. 1
To date, a number of lantibiotics have been shown to use lipid II — a highly conserved peptidoglycan precursor in the cytoplasmic membrane of bacteria — as their molecular target. The α-component (Lchα) of the two-component lantibiotic lichenicidin (Lchα), previously isolated from the Bacillus licheniformis VK21 strain, seems to contain two putative lipid II binding ...
Added: February 21, 2023
Alekseev I., Kraev G., Shein A. et al., Energies 2022 Vol. 15 No. 6 Article 2301
Various research issues related to soil organic matter in permafrost soils are still poorly investigated. At the same time, numerous investigations have shown the importance of permafrost soils, as they serve as a huge reservoir of organic matter. This work is aimed at the investigation of permafrost-affected soils in the southern part of the Yamal ...
Added: October 26, 2022
Galitskaya E., Privalov A., Weigler M. et al., Journal of Membrane Science 2020 Vol. 596 Article 117691
It is established that the values of the coefficients of self-diffusion of water in proton-exchange membranes at a fixed temperature and the amount of moisture content depend on the method of membrane manufacture, the length of the side chain (diameter of channels), but within the experimental error do not depend on the thickness of the ...
Added: October 12, 2022
Galitskaya E., Ulyana M. Zavorotnaya, Ryzhkin I. et al., Ionics 2021 Vol. 27 No. 6 P. 2717–2721
A model of self-diffusion in confined water is proposed. It is based on the idea that confined water forms structures similar to hexagonal ice and its transport characteristics can be described in the framework of a quasiparticle approach. It is assumed that the quasiparticles responsible for self-diffusion are D- and L-bond defects, which in the ...
Added: September 16, 2022
Kuz’mina N. E., Krylov V. I., Moiseev S. V. et al., Pharmaceutical Chemistry Journal 2018 No. 52 P. 159–165
The specificity of different variants of an NMR spectroscopic method for authenticity confirmation of buserelin acetate drug substance was estimated by comparing PMR and 13C NMR spectra of buserelin acetate and [5-D-tyrosine]buserelin acetate in various solvents. Spectra of these diastereomers differed most if deuterated water was used as the solvent. Solvent and intramolecular non-bonded interactions influenced ...
Added: June 17, 2022
Bocharov E. V., Gremer L., Urban A. S. et al., Journal of Medicinal Chemistry 2021 Vol. 64 No. 22 P. 16464–16479
Alzheimer’s disease (AD) is a severe neurodegenerative pathology with
no effective treatment known. Toxic amyloid-β peptide (Aβ) oligomers play a crucial
role in AD pathogenesis. All-D-Enantiomeric peptide D3 and its derivatives were
developed to disassemble and destroy cytotoxic Aβ aggregates. One of the D3-like
compounds is approaching phase II clinical trials; however, high-resolution details of its
disease-preventing or pharmacological actions ...
Added: February 1, 2022
Shakhmatov E., Toukach Ph., Makarova E., Carbohydrate Polymers 2020 Vol. 235 Article 115978
The polysaccharide PGO containing 76% of uronic acids, was obtained from peels and membranes of Punica granatum fruits by extraction to the aqueous solution of (NH4)2C2O4. The chemical structure of PGO was characterized by enzymatic and partial acid hydrolyses, Smith degradation and 1D/2D NMR spectroscopy. It has been found that PGO consisted mainly of highly ...
Added: October 14, 2021