Russian Journal of Physical Chemistry A最新文献

First-principles calculations were performed to investigate the potential of S-doped Mo₂C monolayer as an anode material for magnesium-ion batteries. Our results show that the adsorption energies of Mg on the H₁, T_C1, T_Mo1, and B₄ sites of S-doped Mo₂C are –1.647, –1.565, –1.501, and –1.516 eV, respectively, which are 14.5, 9.4, 6.8, and 7.7% lower than those on the pristine Mo₂C monolayer. These findings indicate that S incorporation enhances Mg adsorption. Mg diffusion between two adjacent favorable sites via a symmetric site on S-doped Mo₂C exhibits fast diffusion. Density-of-states calculations reveal metallic behavior and favorable electronic conductivity for S-doped Mo₂C. Moreover, the S-doped Mo₂C monolayer delivers a high theoretical capacity of 1040.02 mA h g^–1. The open-circuit voltage ranges from 0.32 to 0.87 V, with an average value of 0.51 V. Consequently, S-doped Mo₂C is a promising anode candidate for magnesium-ion batteries.

A temperature-dependent Pitzer–Simonson–Clegg (PSC) model for the binary system LiNO₃ + H₂O was constructed. The phase equilibrium properties of system LiNO₃ + H₂O were simulated by PSC model, and the temperature-dependent parameters of PSC model were obtained by this work, which well reproduced the thermodynamic properties of the binary system LiNO₃ + H₂O including water activity, mean ionic activity coefficient, heat capacity, dilution enthalpy and vapor pressure. Meanwhile, the equilibrium phase diagram of the binary system LiNO₃ + H₂O at 250–420 K were calculated, the result shows that the calculation results were in good agreement with the experimental results reported in the literature.

In this study, the conformational behavior of two dietary dipeptides, H-Trp-Arg-OH (WR) and H‑Trp-Glu-OH (WE), which are agonists of peroxisome proliferator-activated receptor alpha (PPAR-α), was examined using molecular mechanics and molecular dynamics methods. Subsequently, the most stable conformer of each dipeptide, WR and WE, was docked into the PPAR-α ligand-binding domain (PDB ID: 6KB0), DNA (PDB ID: 1BNA), and Human Serum Albumin (HSA; PDB ID: 1AO6) to explore their interaction mechanisms, metabolic roles, and biological activities. The conformational behavior of these dipeptides and the dynamics of their side chains were studied with molecular mechanics, which identified a set of energetically favored conformers. Molecular dynamics studies on the conformational stability of the dipeptides revealed a limited number of stable conformers that tend to adopt unfolded structures. The molecular electrostatic potential (MEP) surface and dipole moment values of the most stable zwitterionic conformation of both dipeptides were calculated at the DFT/B3LYP/6-31++G(d,p) level of theory. Docking studies of WR and WE with DNA (1BNA) showed binding energies of –8.27 and –7.60 kcal/mol, respectively; docking with HSA revealed binding energies of –7.37 and –8.10 kcal/mol, respectively; and docking with 6KB0 showed binding energies of –5.98 and –6.20 kcal/mol, respectively. These docking results clarified the interaction mechanisms between each dipeptide and receptor. Furthermore, the top-scoring WR-6KB0 complex from the docking studies was subjected to 100 ns of all-atom molecular dynamics (MD) simulations to examine the stability of the complex and ligand-receptor interactions in greater detail.

With the aid of density functional theory, the antioxidant properties of resveratrol and its six 2-phenyl naphthalene derivative compounds, as well as their internal influencing factors, were comprehensively analyzed. It was found that the antioxidant activity of 2-phenyl naphthalene compounds is remarkably influenced by the position of the phenol hydroxyl group. The antioxidant activity of compound molecules with a dihydroxy structure is augmented by intramolecular hydrogen bonding. In contrast, the antioxidant activity of the hydroxyl group on the naphthalene ring surpasses that on the benzene ring. This is attributed to the fact that the conjugation of the naphthalene ring is more pronounced, thereby facilitating a higher stability of free radicals. In summary, the higher the antioxidant activity of a given site, the greater the charge on the H atom of the phenolic hydroxyl group and the lower the energy of the hydrogen extraction reaction at that site. Moreover, the stronger the solvent polarity and intermolecular hydrogen bond are, the stronger the antioxidant activity is.

This paper focuses on the preparation, structural characterization, and property investigation of the copper(I) complex [Cu(dppe)(phon)]I based on 1,2-bis(diphenylphosphino)ethane. The target complex was synthesized via a solution method, using 1,2-bis(diphenylphosphino)ethane, cuprous iodide, and 1,10-phenanthroline-5,6-dione as raw materials and acetonitrile as the solvent. It was then characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV–Vis), and fluorescence spectroscopy. Methylene blue was used to simulate dyeing wastewater, and the single-factor method was employed to study the effects of the initial concentration of methylene blue, illumination time, complex dosage, and temperature on the- efficiency. The results indicated that the optimal photocatalytic degradation performance was achieved at a relatively low initial concentration of methylene blue, an appropriate complex dosage (25 mg), and a temperature of 40°C. Additionally, the copper(I) complex was utilized as a phosphorescent probe for the detection of tetracycline hydrochloride, doxycycline hydrochloride, and chlortetracycline hydrochloride. It was found that the addition of tetracycline antibiotics led to a decrease in the fluorescence intensity of the complex, and the higher the concentration of the antibiotics, the stronger the quenching effect. The detection limit of the phosphorescent probe for tetracycline hydrochloride antibiotics was 3.0 × 10^–9 mol/L. This study provides a theoretical basis and practical reference for the application of copper(I) complexes in photocatalytic degradation and tetracycline detection.

The acid-base properties of thiopyrine (TP) were studied in the water–dimethylformamide and water–dimethylsulfoxide solvents containing 25, 50, and 75 vol % DMF and DMSO at 298 K and ionic strength of 0.1 mol/L (NaClO₄). The pK values of thiopyrine were determined over a wide range of pH values. Areas with different forms of thiopyrine were identified depending on the dimethylformamide and dimethylsulfoxide contents. It was established that pK of thiopyrine increases with the content of the organic solvent. Based on the obtained pK values it was found that in aqueous dimethylformamide and dimethylsulfoxide solutions, thiopyrine exhibits the properties of a weak base.

New sorbents based on Silipor 200 have been synthesized. The adsorption properties of their surface in relation to the following classes of organic compounds were studied: aliphatic alcohols, aldehydes, ketones, and esters. Chelate-type complex compounds were used as modifying additives to obtain noncovalently modified adsorbents: cobalt acetyl acetonate, benzoyl acetonate, ethyl acetoacetate, and diethyl malonate. The retention of organic substances was studied by gas chromatography, and the thermodynamic parameters of adsorption and Henry constants were calculated. The influence of the functional groups of the chelate on the adsorption heats, the adsorption entropy change, and the contributions of cobalt chelates on the SiO₂ surface to the retention of adsorbates were determined.

The heat capacity of sodium-cesium trimolybdate NaCsMo₃O₁₀ was measured by the adiabatic method in the range of 5–319 K. No thermal anomalies in the behavior of heat capacity have been found. However, a feature was revealed indicating the presence of a low-frequency peak in the density of phonon states. The Debye temperature at absolute zero was determined by extrapolating the experimental data to absolute zero. Based on the smoothed heat capacity values, the isobaric thermodynamic functions (entropy, enthalpy increment, reduced Gibbs energy) were calculated in the range of 0–320 K.

The physical properties of tritium were determined; its extraction from nuclear plants is required to prevent its penetration into the cooling system and reduce the release of isotopes into the environment. The structural, kinetic, and adsorption properties of compressed tritium containing the tungsten nanoparticle were calculated by ab initio molecular dynamics modeling in the temperature range of 293 ≤ T ≤ 2873 K. The first peak of the partial radial distribution function of W–³H decreases, and the self-diffusion coefficient of tritium continuously increases with temperature. A large number of peaks are present in the spectral density of atomic vibrations of the whole system over the entire temperature range under study. It was concluded that tritium has a high tendency to be adsorbed on the tungsten nanoparticle, and the temperature of the system is the main criterion of the level of this adsorption.

Density functional calculations applied to structural, electronic, and dynamic properties of ferric oxide and its modified Si doping system were explored in detail using the generalized gradient approximation imported in Cambridge Serial Total Energy Package (CASTEP) module. Crystal structures of the studied systems were optimized, and the polymorph prediction of the most organized cluster, identified with a specific space group, was estimated. Significant polymorph clusters were validated using calculated parameters such as energy, density, acceptance rate in the space group, and temperature. Molecular dynamics simulation was performed to support the stability conditions on the material surface. TD-DFT approach was conducted to understand the several electronic transitions inside the designed ferrite and silico-ferrite systems that demonstrated exceptional sensitivity to visible light. Molecular dynamic CO₂-adsorption models were studied to visualize the behavior of the adsorbed CO₂ molecules on the surface of Fe₂O₃ and Si@Fe₂O₃ with planes (0 0 1), in connection with the corrected parameter of basis set superposition error (BSSE). The adsorption annealing study exhibited the best non-covalent interactions between the adsorbed molecules and the surface of the designed systems.