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Vol 99, No 9 (2025)
- Year: 2025
- Published: 15.09.2025
- Articles: 18
- URL: https://journals.rcsi.science/0044-4537/issue/view/24780
CHEMICAL THERMODYNAMICS AND THERMOCHEMISTRY
ENTALPIES OF CRYSTALLOHYDRATES OF Mn(CH3SO3)2·2H2O, Co(CH3SO3)2·4H2O AND Ni(CH3SO3)2·4H2O
Abstract
Crystal hydrates of Mn(CH3SO3)2·2H2O, Co(CH3SO3)2·4H2O and Ni(CH3SO3)2·4H2O were synthesized and identified by X-ray phase analysis, inductively coupled plasma atomic emission spectroscopy and thermogravimetry. The enthalpies of dissolution in water at 298.15 K were determined by dissolution calorimetry and the standard enthalpies of formation of crystalline hydrates of manganese, cobalt and nickel methanesulfonates were calculated. The enthalpic contribution of the methanesulfonate ion to the enthalpy of crystalline methanesulfonate formation in an additive scheme was estimated from the data obtained.
Russian Journal of Physical Chemistry. 2025;99(9):1287-1292
1287-1292
TERMODYNAMIC EQUILIBRIA IN THE Ag-Au-Se-Te SYSTEM AT 25°C AND ATMOSPHERIC PRESSURE
Abstract
The values of the standard Gibbs energies of formation for minerals of the Ag-Au-Se-Te system have been calculated using additive elemental contributions. Calculations of the thermodynamic equilibria of the system under consideration at the initial state of one mole of noble metals and variable chalcogen contents at 25°C and atmospheric pressure were carried out in the “Selector” program complex (PC). The simulation results showed that silver is more actively involved in the composition of minerals than gold. At certain concentrations of selenium and tellurium, noble metals do not form native forms.
Russian Journal of Physical Chemistry. 2025;99(9):1293-1296
1293-1296
HIGH-TEMPERATURE HEAT CAPACITY AND THERMODYNAMIC PROPERTIES OF Bi4-xEuxTi3O12
Abstract
Substituted titanates Bi4-xEuxTi3O12 (x = 0.4, 0.8, 1.2, 1.6 and 2.0) were prepared by roasting in air at temperatures of 1003–1323 K of stoichiometric mixtures of Bi2O3, Eu2O3 and TiO2. Their crystal structure was determined using X-ray diffraction. Their high-temperature heat capacity was measured by differential scanning calorimetry method. Thermodynamic properties of titanates were calculated from experimental data Cp = f(T).
Russian Journal of Physical Chemistry. 2025;99(9):1297-1304
1297-1304
CHEMICAL KINETICS AND CATALYSIS
INHIBITOR PROTECTION OF MILD STEEL IN THE FLOW OF ACID SOLUTIONS OF DIFFERENT ANIONIC COMPOSITION CONTAINING IRON(III) SALTS
Abstract
Corrosion of mild steel in static and dynamic solutions of HCl, HCl + H3PO4 and H3PO4 containing Fe(III) salts, including media containing two-component inhibitor IFKhAN-92 + KNCS has been studied. In the discussed media, partial reactions of anodic ionization of iron, cathodic reduction of H+ and Fe(III) compounds are realized on steel. Iron ionization and proton reduction proceeds with kinetic control, while Fe(III) reduction is characterized by diffusion kinetics. In the solutions under consideration the addition of 4.5 mM IFKhAN-92 + 0.5 mM KNCS inhibits all partial reactions occurring on the metal surface, which is a consequence of its formation of a polynolecular protective layer on the steel. The result of inhibition by the investigated inhibitor in HCl, HCl + H3PO4 and H3PO4 solutions containing Fe(III) salts of all partial reactions realized on the steel surface is its slowing down of its corrosion. The mixture inhibitor strongly retards the corrosion of steel in 2 M H3PO4 and 1 M HCl + 1 M H3PO4, but provides poor protection of the metal in 2 M HCl. This is due to the different ability of the anions of the aggressive medium to bind Fe(III) cations into complex compounds. Phosphate anions, in comparison with chloride anions, more strongly bind Fe(III) cations into complex compounds, determining for them in such media lower values of DFe(III). The protective film of the inhibitor, formed on steel, most effectively slows down the reduction of Fe(III) compounds, present in solution, realized in diffusion mode, with relatively low values of the diffusion coefficient.
Russian Journal of Physical Chemistry. 2025;99(9):1305-1319
1305-1319
IMPLICATION OF LANTHANUM MODIFICATION METHODS ON THE STATUS AND STRUCTURAL PATTERNS OF IRON IN THE CATALYZATOR Fe/MgAl2O4
Abstract
La-modified Fe/MgAl2O4 catalysts were prepared by methods of joint and sequential impregnation of the carrier – alumina-magnesium spinel. The data of TPV (temperature-programmed reduction) and in situ magnetometry showed that the catalyst obtained by lanthanum promotion of spinel is reduced more efficiently in comparison with the catalysts synthesized by other methods of lanthanum introduction into their composition. The data on adsorption and reduction properties of the catalysts by in situ magnetic method, low-temperature nitrogen adsorption and IR spectroscopy of adsorbed CO have been compared. It was found that the presence of lanthanum in the catalyst accelerates the reduction of iron oxides to iron.
Russian Journal of Physical Chemistry. 2025;99(9):1320–1333
1320–1333
PEROXIDE AND AEROBIC DESULFURIZATION CATALYSTS BASED ON HYBRID PLASMA ELECTROLYTICALLY OXIDIZED LAYERS WITH PHOSPHORUS, TUNGSTEN AND IRON OXIDES
Abstract
Catalytically active coatings on titanium were synthesized by plasma electrolytic oxidation (PEO) in aqueous electrolytes containing sodium phosphate and tungstate, as well as iron chelate complexes with EDTA. Analysis of EDX, XPS and XRD data allowed concluding that the PEO coatings contain titanium dioxide and amorphous tungstates and/or phosphates of iron. High phosphorus concentrations (up to 6 at. %) promoted amorphization. Testing the PEO catalysts showed their activity in oxidative desulfurization (ODS) of thiophene and dibenzothiophene with hydrogen peroxide and air oxygen.
Russian Journal of Physical Chemistry. 2025;99(9):1334-1343
1334-1343
PHYSICAL CHEMISTRY OF SOLUTIONS
MIXED LIGAND COMPLEX CONSTRUCTION OF NICKEL(II) AND ZINC CATIONS WITH HISTIDINE, LYSINE AND ARGININE IN AQUEOUS SOLUTION
Abstract
The formation of mixed-ligand complexes of different composition in the systems M(II) – L-histidine (His) – L (M = Ni, Zn; L = L-lysine (Lys), L-arginine (Arg)) has been studied by pH-metry and spectrophotometry methods and their formation constants have been calculated at 298.15 K and ionic strength I = 0.5 mol/L (KNO3). Based on the comparative analysis of the coproportioning reaction constants, the dentativity of the ligands was evaluated and the most probable way of coordination of amino acid residues in the mixed complexes was proposed.
Russian Journal of Physical Chemistry. 2025;99(9):1344-1351
1344-1351
STRUCTURE OF MATTER AND QUANTUM CHEMISTRY
QUANTUM CHEMICAL MODELING INTERMOLECULAR INTERACTIONS OF AROMATIC AMINO ACIDS AND SORBENTS
Abstract
The results of quantum-chemical modeling of intermolecular interactions between hydrophobic amino acids (phenylalanine and tryptophan) and the aromatic element of the sorbent matrix, the main contribution to which is made by π-π interactions, are considered. It was found that for both amino acids parallel and T-shaped arrangement of aromatic structures of the amino acid and sorbent relative to each other is realized. For tryptophan, in addition, the T-variant arrangement with orientation of the heteroatom of the amino acid radical to the ring of the sorbent matrix is realized. The results of quantum-chemical modeling of the formation of the second sorption layer in the sorbent due to π-π interactions are considered. The energy and geometrical characteristics in the above systems have been analyzed.
Russian Journal of Physical Chemistry. 2025;99(9):1352-1359
1352-1359
ELECTRON IMPLICATIONS OF VALENT MOLECULAR ORBITALS IN THE POPULATION OF AnO2 (An = Th – Lr) RELATIONSHIPS
Abstract
Abstract. The dependence of contributions of electrons of valence molecular orbitals (MOs) of AnO2 (An = Th – Lr) to bond occupancies (according to Malliken) on the atomic number Z has been obtained by the relativistic method of discrete variation. It has been observed that electrons of external valence MOs (VVMOs) strengthen the bonding, while electrons of internal valence MOs (IVMOs) weaken such bonding on average by one-third. The efficiency (observed in the experiment) of VVMO formation characterizes the peculiarity of chemical bonding of actinide dioxides. With increasing Z, the influence of valence MO electrons on the covalent bond significantly decreases and it acquires a more ionic character. Significant effects of covalent bonding in AnO2 are observed due to the overlap of not only An 6d- but also An 6p- and An 5f-atomic orbitals with ligand orbitals.
Russian Journal of Physical Chemistry. 2025;99(9):1360-1367
1360-1367
PHYSICAL CHEMISTRY OF NANOCLUSTERS, SUPRAMOLECULAR STRUCTURES, AND NANOMATERIALS
INFLUENCE OF SYNTHESIS PARAMETERS ON ELECTROCHEMICAL PROPERTIES OF Ge-Co-In NANOSTRUCTURES
Abstract
This work presents the results of investigation of the influence of synthesis parameters of Ge-Co-In nanostructures on their electrochemical properties. It was found that the optimal ratio of aqueous complex solutions of Ge (IV) and Co (II) is GeCo (3:2), at which the obtained sample has the highest Coulombic efficiency at the first cycle equal to 80% and reversible capacity with respect to lithium introduction about 1190 mAh/g. In turn, increasing the solution temperature to 40°C allows to obtain a sample which has a Coulombic efficiency at the first cycle of about 92% without the use of special organic additives in the electrolyte.
Russian Journal of Physical Chemistry. 2025;99(9):1368–1375
1368–1375
INFLUENCE OF THE POLYMER STABILIZER STRUCTURE ON THE SPECTRAL AND MORPHOLOGICAL CHARACTERISTICS OF RADACHLORINE IN THE SELENIUM–CONTAINING NANOSYSTEMS
Abstract
Comparative studies of the new triple selenium-containing nanosystems (SCNs) based on the photosensitizer Radachlorine (Rd) and amphiphilic molecular brushes (graft-copolymers) with the polyimide or cellulose main chain and polymethacrylic acid (PMAC) side chains have been carried out using UV/visible spectroscopy, atomic force microscopy (AFM) and luminescence. The influence of the graft copolymer structure on the spectral and dimensional characteristics of the amphiphilic molecular brushes loaded with selenium and Rd NPs has been established. It was found that amphiphilic molecular brushes prevented association of the selenium NPs in the solution, forming discrete spherical nanostructures. It is suggested that the formation of triple SCNs is carried out mainly due to the steric stabilization of the selenium NPs by macromolecules of the brushes and the embedding of the selenium NPs inside the Rd porphyrin ring according to the type of metal-porphyrin complexes. Based on UV/visible spectroscopy and luminescence data, the values of the band gap energy, the diameter of the selenium nanoparticles, and the luminescence quantum yield were calculated for SCN.
Russian Journal of Physical Chemistry. 2025;99(9):1376-1386
1376-1386
INFLUENCE OF STIRRING SPEED ON KINETIC AND MORPHOLOGICAL PARAMETERS OF GROWTH OF AMORPHOUS SILICA NANOSPHERES OBTAINED BY THE STOBER METHOD
Abstract
Calorimetric and conductometric analysis methods in online mode for the synthesis of silica globules have been used. The dependence of the initial reaction rate of sol synthesis on the stirring rate of the reaction mixture was obtained. The stirring regions corresponding to diffusive and kinetic character of synthesis at the ratio of components Si(OC2H5)4 : H2O : NH3H2O – 0.2 : 18.9 : 2.0 (mol l−1) have been revealed. The kinetic region lies in the stirring frequency range of 7–23 Hz, which is characterized by a constant process rate and quality of the grown nanospheres, and the diffusive one up to 7 Hz with varying synthesis parameters. SEM-photographs of samples with determination of average sizes and deviation of sizes at different stirring speeds were analyzed. Morphological defects of nanospheres grown in the diffusion synthesis mode have been observed.
Russian Journal of Physical Chemistry. 2025;99(9):1387-1393
1387-1393
ХЕМОИНФОРМАТИКА И КОМПЬЮТЕРНОЕ МОДЕЛИРОВАНИЕ
MODELING OF GOLD IN THE MODEL OF EMBEDDED ATOM
Abstract
Using pair correlation functions of liquid gold Waseda, the pair contributions to the EAM potentials at temperatures of 1423, 1573, 1773, and 1973 K are calculated using the Schommers algorithm. The parameters of the embedded potential were found taking into account the temperature dependence of the density, energy and compressibility of liquid gold. At 1973 K the diffraction data are not accurate enough for further calculations. It is shown that the EAM potential calculated at 1423 K allows us to build sufficiently adequate models of gold at temperatures up to 3000 K. The calculated self-diffusion coefficients are 25–30% lower than those obtained on the basis of the effective medium theory, but in general the computer calculations of atomic mobility agree quite well.
Russian Journal of Physical Chemistry. 2025;99(9):1394-1402
1394-1402
PHYSICAL CHEMISTRY OF DISPERSED SYSTEMS AND SURFACE PHENOMENA
INFLUENCE OF THE STRUCTURE OF DERIVATIVES OF PYRIDAZINO[4,5-C]QUINOLINE AND QUINOLINE DERIVATIVES ON THEIR SORPTION ON OCTADECYLISILICA GEL
Abstract
The relationship between the molecular structure of pyridazino[4,5-c]quinoline and quinoline derivatives and their retention under reversed-phase high-performance liquid chromatography on octadecyl silica gel has been analyzed. The influence of physicochemical parameters and spatial structure of the molecules of the studied compounds on the change of retention factor values is shown.
Russian Journal of Physical Chemistry. 2025;99(9):1403-1410
1403-1410
ELECTROCHEMISTRY. GENERATION AND STORAGE OF ENERGY FROM RENEWABLE SOURCES
STATISTICAL THEORY OF DIELECTRIC PROPERTIES AND RELAXATION PROCESSES OF ELECTROLYTE SOLUTIONS
Abstract
On the basis of kinetic equations for unary and binary distribution function, analytical expressions for dynamic dielectric coefficients ε1(ν) and dielectric loss ε2(ν) of electrolyte solutions have been obtained for cases when the restoration of the equilibrium structure of the solution occurs according to the law of diffusion or exponentially. Under a certain choice of the intermolecular interaction potential Φab(|r|) and radial distribution function gab(|r|), numerical calculations of ε1(ν) and ε2(ν) as a function of temperature T, density ρ, concentration C, and frequency ν have been carried out for aqueous solutions of sodium chloride. The obtained results of numerical calculations are in qualitative agreement with the experimental data. The frequency dispersion of ε1(ν) and ε2(ν) coefficients depending on the mechanism of relaxing flow attenuation has been investigated. It is shown that the frequency dispersion region of ε1(ν) and ε2(ν), based on the diffusion mechanism, is wide ~105 Hz, and in the case of exponential damping of the relaxing flow, is narrow ~102 Hz, which is consistent with the results of phenomenological relaxation theory.
Russian Journal of Physical Chemistry. 2025;99(9):1411-1419
1411-1419
PHOTOCHEMISTRY, MAGNETOCHEMISTRY, MECHANOCHEMISTRY
LUMINESCENCE PHOTOELIMINATION ANALYSIS OF THE SULFOGROUP OF 4-METHYL-1-SULFOANTHRACENE IN AQUEOUS SOLUTIONS OF PERCHLORIC ACID
Abstract
By methods of photochemistry and luminescence analysis it has been shown that 4-methyl-1-sulfoanthracene eliminates the sulfogroup with a yield of α-methylanthracene of ~70% when it is irradiated in a medium of 47–65% perchloric acid by the light of a mercury-ball arc lamp DRSH-1000. The process is single-photon and proceeds with the participation of the S1 singlet level, which is deactivated faster than the elimination of the sulfogroup. The hydrolysis of the sulfogroup is realized under conditions of specific acid catalysis, and at high acidity of the medium (H0 < –2) the reaction proceeds without affecting the meso-position of the anthracene nucleus. Quantum yields of dissociated and undissociated forms of 4-methyl-1-sulfoanthracene, activation energies of photodesulfation and luminescence quenching, lifetime of the excited state of the molecule and constants of kinetic equations were determined.
Russian Journal of Physical Chemistry. 2025;99(9):1420-1424
1420-1424
ФИЗИЧЕСКАЯ ХИМИЯ ПРОЦЕССОВ ГОРЕНИЯ И ВЗРЫВА
THE ROLE OF DIFFUSION PROCESSES IN DETERMINING THE PARAMETERS OF THERMAL EXPLOSION OF ENERGY COMPOSITE MATERIALS
Abstract
Comparison of calculated and experimental delay periods of thermal autoignition τ of rocket propellant samples of NEPE type with characteristic sizes from 20 to 100 mm is presented. The experimental data obtained in the isoperibolic regime are taken from literature sources. In our calculation we used the model of chain reaction of thermal decomposition of nitroether plasticizers in NEPE composition. The calculated values of τ depend weakly on the sample size, but they are significantly (for small sizes – several times) smaller than those obtained in experiments. It is shown that the reasons for the discrepancy between the calculated and experimental values of the autoignition delay periods were the loss of active particles – decomposition products of nitroethers (primarily NO2) both due to interaction with stabilizers and due to their migration into the environment due to leaky packing of samples. The role of migration phenomena is considered on the example of the solution of the diffusion equation, which takes into account the nucleation, multiplication and death of active particles.
Russian Journal of Physical Chemistry. 2025;99(9):1425-1430
1425-1430
БИОФИЗИЧЕСКАЯ ХИМИЯ И ФИЗИКО-ХИМИЧЕСКАЯ БИОЛОГИЯ
META-ANALYSIS OF ACID-BASE AND REDOX PROCESSES WITHIN THE MITOCHONDRIAL MATRIX, CYTOPLASM, INTERCELLULAR MEDIUM AND BLOOD BASED ON THE TENSOR APPROACH
Abstract
The most important indicator of homeostasis is the acid-base balance (ABB), which for the last half century in clinical practice has been assessed based on the Boston or Copenhagen schools, or relying on the physicochemical interpretation proposed by P. Stewart, which changed the emphasis from direct pH readings to the generalized state of electrochemical equilibrium of the blood. Today, it is generally recognized that all three approaches to assessing the ABB have weaknesses, and they do not have convincing clinical advantages. Since it has been experimentally established that with metabolic acidosis, 57% of buffering is carried out intracellularly, it is more appropriate to consider the ABB not as a purely isolated blood indicator, but to assess it within the framework of energy metabolism (dissimilation), which is a consequence of oxidation-reduction reactions within the mitochondrial matrix, their intermembrane space and the cell cytoplasm, which can be solved by mathematical modeling. The use of tensor notation for mathematical model equations is not only the adoption of standardization rules, but a far-reaching ideology of the invariance of these equations (preservation during transformations of a certain group). The presented work shows that acid-base and oxidation-reduction homeostasis in mathematical model equations can be interpreted as “play” (variations within established boundaries during transformations of a certain type) for specially formulated tensor invariants.
Russian Journal of Physical Chemistry. 2025;99(9):1431–1442
1431–1442