Russian Journal of General Chemistry最新文献

The electronic structure and thermochemical formation of complex from gadolinium chloride and meso-tetraphenylporphyrin in presence of imidazole molecules were calculated using the Minnesota functionals family, ωB97XD, B3LYP and PBE0 with the all-electron ahlrichs_x2c vs ahlrichs_def2 with ECP and SDDall basis sets. Enthalpies and Gibbs free energies of all possible formations of ClGdTPP coordinated with different numbers of imidazole ligands (up to 2) and side products were compared. The coordination compound ClGdTPP·2Im was found as the most energetically preferable complex of the discussed reaction in molten imidazole medium at high temperature. Electronic structures and high multiplicities of intermediate gadolinium compounds and final coordination complexes were considered in details.

Novel polyindole (Pin) and/or graphene (Gr)/chromium dioxide (CrO₂) nano-composites have successfully formed employing chemical and electrochemical (cyclic voltammetry technique) polymerization method in a deep eutectic solvent (DES), which was used as the polymerization medium. FTIR and UV-Vis spectroscopies, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and voltammetric measurements were utilized to investigate electro/chemical properties of the Pin composites. Good conductivity was seen for the polyindole/graphene up to (5.56 S/cm) and polyindole/graphene/CroO₂ (9.85 S/cm) nanocomposites compared with pure polyindole (1.25 S/cm). The electrical stability of polymer films prepared in aqueous medium was studied. The results showed that the films possess remarkable electrical stability. The conductivity was also studied at different temperatures and the results showed that the conductivity increases with increasing temperature. The homogenous development of polyindole layers on electrode substrate were clearly observed by scanning electron microscopy technique and E-DAX. An increasing in surface area and porosity were accomplished in the polyindole composites compared to structure of polyindole surface. These findings give concept that the prepared composites would be valuable candidate for electrochemical applications.

In light of the escalating environmental pollution crisis, the pursuit of innovative, sustainable, and economically viable materials for the remediation of heavy metal-contaminated wastewater has emerged as a critical imperative in contemporary environmental science and engineering. Humic acid, as a widely distributed macromolecular organic matter, has a unique surface structure and abundant functional groups, possessing many characteristics of adsorption, complexation, and flocculation. It can bind with heavy metal ions and effectively treat heavy metal wastewater. However, there is a lack of detailed description and research on the microscopic mechanism of atomic-level interactions. As an important method for studying the electronic structure of multi-electron systems, density functional theory plays a crucial role in calculating material properties, simulating chemical reactions, and quantifying structure-activity relationships. Especially it has unparalleled advantages of revealing the microstructure and mechanism of action of materials. In this article, the current status of density functional theory, computational methods, and their application fields, combined with the structural characteristics of humic acid and its binding properties with heavy metal ions was introduced. The application research of density functional theory in the micro mechanism of humic acid and heavy metal ion binding was summarized. Meanwhile, the advantages and disadvantages of density functional theory in the micro mechanism of humic acid and heavy metal ion binding were reviewed. Finally, a focused prospect was made on the potential development directions of its future research.

This study explores the halogen bonding interactions between dibenziodonium cation and flexible triethylene glycol derivatives (HO¹CH₂H₂O²CH₂H₂O³CH₂H₂O⁴H and PhO¹CH₂H₂O²CH₂H₂O³CH₂H₂O⁴Ph through a combination of ¹H NMR titration and quantum chemical calculations. NMR studies in CDCl₃ revealed a significantly higher binding affinity for the unsubstituted glycol over its phenyl-substituted analogue, with association constants of 160 and 3.04 M^–1, respectively. This disparity, alongside the absence of binding in the competitive solvent DMSO, highlights the critical influence of ligand substituents and solvation. DFT calculations elucidated the thermodynamic preference for macrocyclic-type coordination via non-vicinal oxygen atoms (O¹, O³ and O¹, O⁴ modes) over chelation at vicinal sites. This preference is attributed to the geometric requirement for simultaneous engagement of the iodonium cation σ-holes. These results provide key design principles for tuning supramolecular recognition and catalysis based on iodonium-based halogen bond donors.

A nickel-catalyzed cross-coupling reaction between unactivated difluorosubstituted aromatic ketones and aryltitanium reagents in the presence of a ligand and LiCl as an additive is reported, showing excellent ortho-selectivity. The reaction exhibits good functional group tolerance and a wide substrate range, providing medium to high yields of the ortho-arylated products.

A series of isoxazole-benzimidazole hybrids were synthesized via click chemistry, employing the reaction of terminal alkynes with substituted aldoximes. The catalyst DBU was utilized due to its accessibility and cost-effectiveness. The newly synthesized analogues were characterized using mass spectrometry, ¹H NMR, and IR spectroscopy techniques. Their antioxidant activities were evaluated through DPPH and nitric oxide scavenging assays, demonstrating significant efficacy against the tested organisms. To further support the potent antioxidant properties of compounds in silico molecular docking studies were conducted using ascorbic acid as a reference ligand extracted from the cytochrome c peroxidase enzyme (PDB code: 2X08). Additionally, in silico ADMET studies revealed that compounds exhibited no toxicity or carcinogenicity. Characterization of molecule was achieved using density functional theory (DFT) with the B3LYP/6-311++G(d, p) basis set, providing structural parameters through geometry optimization. Molecular electrostatic potential (MEP) and HOMO–LUMO energy gaps were also calculated. Thus, this approach successfully combined the bi-heterocyclic structures of isoxazole and benzimidazole using innovative copper-free, oxime-based click chemistry techniques.

(Z)-4-Arylidenehexahydro-2H-pyrido[1,2-a]pyrazin-3(4H)-ones were synthesized starting from (Z)-4-arylidene-2-phenyl-1,3-oxazol-5(4H)-ones and piperidin-2- ylmethanamine, and optimal conditions for their synthesis were found. It was found that (Z)-arylidenehexahydro-2H-pyrido[1,2-a]pyrazin-3-(4H)-ones undergo cleavage in an acidic medium to form 2-piperidylmethylamides of 2-oxopropionic acids. UV spectra, mass-spectra and anticholinesterase properties of the synthesized compounds were studied.

Substituted tetrahydroquinoline (THQ) derivatives were systematically designed and synthesized via a three-component Povarov reaction, employing N-vinyl carbamate, organocatalyzed substituted anilines, and benzaldehyde derivatives. The resulting THQ derivatives demonstrated a diverse range of functional groups, which potentially broadens their applicability. These compounds were rigorously characterized using various spectroscopic techniques to verify their structures. Subsequent bioevaluation of the synthesized THQs revealed their inhibitory activity against acetylcholinesterase (AChE), highlighting their potential as therapeutic agents for neurodegenerative diseases. All synthesized THQs exhibited IC₅₀ values ranging from 0.22 to 0.36 μM, which are lower than the IC₅₀ value of the standard compound tacrine (0.77 μM). The K_i values for the THQs against AChE ranged from 0.370±0.330 to 1.30±0.715 μM. Additionally, molecular docking studies of the THQ-AChE complexes yielded binding scores between –10.8 and –12.4 kcal/mol. The structure-activity relationship (SAR) analysis underscores the significance of THQ structures in medicinal chemistry. These findings suggest that the structural insights gained from this study will be valuable for the future design and synthesis of potent AChE inhibitors.

A novel, reagent-efficient spectrophotometric approach for detecting trace water in organic solvents is presented, exploiting competitive halogen bonding (XB) between the iodonium-based σ-hole donating diphenyliodonium triflate, the azo-dye methyl orange, and water molecules. Unlike conventional Karl Fischer titration, this strategy leverages the distinct spectroscopic response arising from preferential complexation of water molecules by the XB donor: UV-vis titration studies in acetonitrile reveal that water saturates the electrophilic σ-hole of the iodonium cation at concentrations up to ~70 equivalents, inhibiting dye coordination. Subsequent addition of diphenyliodonium triflate triggers a sharp, concentration-dependent chromogenic shift, signaling water depletion and formation of the iodonium cation∙∙∙methyl orange charge-transfer complex. This sequence—validated by ¹H NMR titration and DFT calculations—enables the visual and spectroscopic identification of water. The study establishes a fundamental concept for moisture sensing, demonstrating operational simplicity and potential for dipstick adaptation. This XB-mediated strategy offers a promising foundation for the future development of alternative moisture detection tools for applications in synthesis, pharmaceuticals, and quality control.

Silver nanoparticles with enhanced antibacterial activity were fabricated by green reduction method with tannic acid for utilizing the synergistic antibacterial effect of tannic acid and silver nanoparticles. The chemical composition and morphology of the tannic acid-stabilized silver nanoparticle were characterized by using Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron and transmission electron microscopy. The optimal preparation conditions for tannic acid-stabilized silver nanoparticle were the molar ratio of tannic acid solution to AgNO₃ of 1 : 4, the pH value of tannic acid solution of 10, the reaction time of 30 min, and the reaction temperature of 60°C. The prepared tannic acid-stabilized silver nanoparticle showed excellent antibacterial effects against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.