Russian Journal of General Chemistry最新文献

For the first time, the theoretical foundations for building the structure of particulate-filled polymer composite materials (PFPCMs) are presented from the standpoint of joint examination of Shklovsky-de Gennes model ideas concerning the formation of the structure of dispersed fillers in space and, proposed by us, a generalized model, including the creation of free space, its filling with a polymer matrix (binder) and its functional division into three components: φ_p = θ + B + M (θ is the proportion of the polymer phase-matrix for the formation of an interlayer between the filler particles; B is the proportion of the polymer phase-matrix at the maximum packaging of the dispersed phase; M is the proportion of the polymer phase-matrices in boundary layers). Correlation dependences between the parameters of heterogeneity in space (lattice parameters: Z and k_pac) and the generalized parameter θ were established, all PNPCMs were classified according to the structural principle [structure type: DS—diluted, LFS—low-filled, MFS—medium-filled (MFS-1 and MFS-2) and HFS—highly filled dispersed systems]. Generalized (θ, V, M) and reduced parameters (θ/V and θ/S_n) are proposed to describe the structure of the PFPCMs. Experimental methods have been developed for determining the main parameter of a dispersed filler for constructing PFPCMs structures—the maximum packing (k_pac) and the maximum content of dispersed fillers (parameter φ_m) of different sizes. It is shown that the construction of all possible types of structures and compositions of PFPCMs should begin with HFS at the content of dispersed filler equal to φ_m (fixed starting point), similar to the construction of the stepped CHICHEN ITZA PYRAMID with the apex—HFS, the base—a polymer matrix (PM) and with steps—different types of structures (MFS-2, MFS-1, LFS and DS). The dependences of the physicochemical, rheological, physicomechanical, electrophysical, thermophysical characteristics of PFPCMs on the generalized and reduced parameters, as well as on the lattice parameters Z and k_pac of the dispersed filler are established, and it is shown that the type of structure and its parameters determine the properties of PFPCMs. The obtained dependencies for the first time made it possible to compare the characteristics of PFPCMs with the same types of structures, and not at a constant value of the content of the dispersed phase (φ_f = const), which is not correct. This concept is the basis for the creation of high-tech, high-strength, heat-conductive and heat-insulating, as well as electrically conductive, etc. PFPCMs. New theoretical provisions can be extended to the construction of structures of composite materials based on metal and ceramic matrices.

This review summarizes the intricate structural features and characterisation of graphene oxide (GO), as well as its many derivatives and wide-ranging uses. GO exhibits adaptability across a range of applications, including environmental remediation and biological purposes. The use of this material extends to both the fabrication of freestanding membranes and their incorporation into other composite systems. Gaining an in-depth understanding of the structure and features of GO is vital for effectively using its promise in many fields. Scientists constantly discover new uses and improve the techniques of creating it to boost its capabilities. GO, in environmental environments, facilitates and removing of pollutants as well as water purification. The biocompatibility and drug delivery characteristics of this substance are advantageous in the fields of medicine and biology. Furthermore, membranes based on graphene oxide are useful in filtering technologies. Systems that combine graphene oxide have improved mechanical, electrical, and thermal characteristics, which hold great potential for breakthroughs in the field of materials research. Overall, the complex and versatile character of GO highlights its significance in several disciplines and emphasises its reputation as a material with great promise.

In the article, electrochromic WO₃ films were obtained from 25, 100, and 200 mM peroxytungstic acid (PTA) solution. A chronoamperogram of the cathodic reduction of tungsten oxide (WO₃) through the stages of formation of a precursor film adsorbed on the surface of the ITO electrode and its subsequent staged reduction to WO₃ and side formation of soluble reaction products is presented. The material yield of the WO₃ film on ITO glass was within 50%, which is due to the parallel occurrence of side processes associated with hydrogen evolution and the reduction of tungsten complexes that were in the precipitation solution (WO₃ reduction scheme). In this case, it was taken into account that thin WO₃ films were the final product. The features of the synthesis of peroxytungstic acid have been studied. It has been shown that the reaction of W dissolution in 37% H₂O₂ proceeds exothermically. In this case, the reaction temperature reached 96°C within a few seconds, and its decline varied exponentially with the formation of reaction products. The dependence of the limiting current on the square root is obtained. The presented graphic dependence is characterized by linearity, while the beginning of the straight line does not coincide with the origin. The process of intercalation-deintercalation of protons (H⁺) (cathode-anode branches of CV) was a consequence of structural and reversible changes as a result of H⁺ intercalation. WO₃ films obtained by electrochemical (cathodic) deposition can be recommended as an electrode material for electrochromic devices (cathode) and as a material for electrochemical sensors. Another promising direction is the development of a wide band gap anode based on WO₃ for photovoltaic devices, which are energy efficient hydrogen generation systems.

This mini-review summarizes the latest advances in the study of the anticancer activity of azo compounds. The data shows the high potential of this class of compounds, which allows us to determine the existing vectors of development in this area, and evaluate the effectiveness of the modifications of azo compounds. The review covers the period from 2006 to 2022.

The metalation of 1,3-diaryl-4-(arylsulfanyl)imidazolium and 1,3-diaryl-4-(arylsulfonyl)imidazolium chlorides with copper(I) oxide has been studied. The resulting Cu/NHC complexes have been studied as catalysts for the carboxylation of phenylacetylene, benzoxazole, and benzothiazole. The main patterns of this reaction behavior and the dependence of the catalysis efficiency on the NHC structure were revealed.

A one-pot multicomponent method employing substituted indole, ethyl cyanoacetate and aromatic aldehyde was found as an effective catalytic procedure for the synthesis of a novel indole derivatives. The potential of CuO nanoparticles as nanocatalysts for the Knoevenagel condensation and the synthesis of new indole derivatives was investigated. X-Ray diffraction was used to measure the size of the CuO nanoparticles. CuO nanoparticles can be recycled and used again after the reaction course. The ADMET analysis and drug-likeness results indicated that indole derivatives satisfied Lipinski’s principles and drug-likeness requirements. The reactivity indices and potential areas obtained from the FMO experiments were successfully used to a range of molecular systems because they yield valuable information. Here, we determined the oxobutanoate derivative’s critical areas and likely reactivity directions. The resultant indole derivatives were subjected to various analytical techniques, including mass spectroscopy, ¹H and ¹³C NMR spectroscopy, FT-IR and mass spectrometry.

A rapid and sensitive dispersive liquid–liquid microextraction (DLLME) method coupled with UV-Vis spectrophotometry has been developed and validated for the determination of metoclopramide in pharmaceutical and biological samples. The method is based on the formation of an ion-pair complex between metoclopramide and cobalt(II) thiocyanate under acidic conditions (pH = 3), followed by DLLME to efficiently preconcentrate the chromogenic complex. In the novel DLLME procedure, methylene chloride was used as the extraction solvent and acetonitrile acted as the dispersive solvent, generating a cloudy heterogeneous mixture upon injection into the aqueous sample. This facilitated extensive interfacial contact and partitioning of the metoclopramide-cobalt complex into the fine dispersed methylene chloride droplets within minutes. After centrifugation, the sedimented organic phase was analyzed at the maximum wavelength of 625 nm. Under optimal conditions, the method permitted quantification of metoclopramide from 0.25–45 µg/mL with high enrichment factors, and LOD of 0.078 µg/mL, LOQ of 0.258 µg/mL and high extraction recoveries in the range of 94–101% were obtained. The proposed DLLME-spectrophotometric methodology provides a simple, rapid and sensitive approach for routine therapeutic monitoring and quality control of metoclopramide in real samples.

A new phosphaneoflavonoid was obtained by the reaction oxaphosphinine with β-resorcylic acid. A method was proposed for the synthesis of new unsymmetrical cage phosphonates based on 4-aryl-2-hydroxy-5,7,8-trimethylbenzo[e][1,2]oxaphosphinine-2-oxides as a result of intramolecular heterocyclization. Composition and structure of all the obtained compounds were confirmed by ¹H, ¹³С and ³¹P NMR, IR spectroscopy and mass spectrometry data.