Vol 69, No 1 (2024)

Photosensitive thin films of tin (II) sulfide with p-type conductivity and a band gap of 1.03 ± 0.09 eV have been obtained within the framework of the principles of «green chemistry» using the one-pot approach. In order to expand the range of sulfidizers used in the technology of deposition of thin nanostructured SnS films by chemical deposition, the efficiency of using sodium thiosulfate solutions is shown. It has been found that thin SnS films with good adhesion to a dielectric substrate and a size of coherent scattering regions of about 30 nm can be obtained as a result of a chemical reaction of the hydrolytic decomposition of thiosulfate ions. The conditions for obtaining SnS are substantiated by the thermodynamic analysis of ionic equilibria. Quantum-chemical calculations show that the p-type conductivity of the synthesized SnS films is most likely due to tin vacancies.

Among germatranes, 1-germatranol hydrate is the most well-studied compound with a diverse spectrum of biological activity. Its synthesis is based on a one-stage reaction of tris(2-hydroxyethyl)amine with germanium dioxide in an aqueous medium without the use of organic solvents. In this work, taking into account this approach, new potentially biologically active compounds of germanium with hydroxyalkylamines, sulfo- and amino acids containing hydroxyalkyl groups were synthesized, which we considered as new analogues of biologically active 1-germatranol hydrate. Their formation is confirmed by the results of elemental analysis, IR and NMR spectroscopy. In silico ADME and Pass analysis were used to assess the potential bioavailability and pharmacological activity profile of new compounds. The results of an in vitro study of the antiviral activity (influenza A/Aichi/2/68 (H3N2) virus) of synthesized compounds are presented.

Mn(III)-5-(4-nitrophenyl)-10,15,20-triphenylporphyrin and Mn(III)-5,10,15-tri-(4-nitrophenyl)-20-phenylporphyrin were synthesized using the reactions of complex formation of corresponding porphyrins and metal exchange of their Cd complexes with MnCl₂ in dimethylformamide. Partial reduction of Mn(III) to Mn(II) is observed upon dissolution of manganese(III) complexes in dimethylformamide. When NaOH solid is added to a solution of dimethylformamide and in ethanolamine unstable Mn(II) porphyrins are formed. The photochemical stability and oxidative degradation of Mn(III)-porphyrins have been studied. The metal exchange reaction of asymmetricaly substituted Cd(II)-porphyrins with manganese chloride in dimethylformamide has been studied. The kinetic parameters of the reaction were calculated. The influence of substituends and the nature of the salt on the kinetic parameters of the metal exchange reaction was revealed. The synthesized compounds were identified by methods UV-Vis, IR, ¹H NMR spectroscopy and mass spectrometry.

Owing to its unique properties, oxygen-free ceramics are promising for use in various branches of technology. The inclusion of metals or their compounds in this ceramic significantly expands the possibilities of its application. Therefore, methods for the synthesis of such composites are being actively developed. One of the ways to obtain such films is the deposition from the gas phase. Thermodynamic modeling allows you to choose the conditions for this process. In this work, thermodynamic modeling of the CVD process in the Ni-Si-C-H system, where nickelocene and silane were precursors, was carried out. The results of the work can be useful for developing methods for obtaining film materials based on SiC and nickel-containing phases.

Series of samples of quasi–ternary Li₂O–Mn₂O₃ – Eu₂O₃ system, synthesized from of precursors subjected to preliminary mechanochemical activation and annealed in air at temperatures of 700–1100°C have been systematically studied by powder X–ray diffraction(pXRD) and thermal analysis (TG–DSC) methods. The possibility of substituting Mn for Eu for the LiMn_2–xEu_xO₄ spinel phase is estimated. Within the framework of the Li–Mn–Eu concentration triangle, a subsolidus isobaric diagram and a projection of the liquidus surface of the Li–Mn–Eu–O system were constructed using models of polythermal phase diagrams of the LiEuO₂–LiMnO₂ and LiEuO₂–LiMn₂O₄ sections. The temperatures of eutectic equilibria with the participation of three crystalline phases and a melt were determined.

Theoretical analysis of the process of quasi-equilibrium directed crystallization of a three-component melt is carried out in this paper. The change in the composition of phases at each of the sample sites and the phase composition transformation for different types of phase reactions are considered. It is shown that at directional crystallization there are possible cases of transition of eutectic reaction to peritectic reaction at lowering of temperature. The directional crystallization of Fe 29.96, Cu 21.55, Ni 2.01, S 46.49 at. % melt was carried out. Since nickel was present in the ingot in the form of impurities dissolved in the phases of the Cu-Fe-S system, it is possible to consider the behavior of the melt belonging to this three-component system when interpreting the data. As a result of which a sample with three zones has been obtained: single-phase from Fe_zS_1±d (Poss), two-phase from eutectic mixture of Poss and (Cu,Fe)_1+xS (Iss) and single-phase from Iss. During the transition from one zone to the next, the average composition of the solid phase changes discontinuously, while the compositions of the melt and solid solutions present in neighbouring zones change continuously. These results are consistent with theoretical representations.

The solubility in the context of a complex aqueous system consisting of chloroethylphosphonates, phosphate, ammonium sulfate and sodium tricarbamide chlorate in the range of -21— +52°C was studied by a visual-polythermal method. A polythermal phase diagram has been constructed, on which the crystallization fields of ice and system components are delimited. The formation of a new compound of ammonium chloroethylphosphonate monochlorate NH₄ClO₃ ∙ ClCH₂CH₂HPO₃NH₄ was established, the composition of which was confirmed by the methods of chemical and physicochemical analysis. The viscosity, density (at 25°C) and crystallization temperature of a number of mixtures in the context of the system [65%NaClO₃∙3CO(NH₂)₂+5%(NH₄)₂SO₄+30%H₂O]-[21%ClCH₂CH₂PO(OH)₂∙NH₃+11%ClCH₂CH₂PO(OH)₂∙2NH₃+12%NH₄H₂PO₄+56%H₂O].

This work demonstrates ex situ characterization of molybdenum oxide (MoO₃) and titanium–molybdenum oxide (Ti_xMo_yO_z) thin films obtained at 150°C by atomic layer deposition using titanium tetrachloride (TiCl₄), molybdenum oxotetrachloride (MoOCl₄) and water. Atomic layer deposition of Ti_xMo_yO_z was carried out using supercycles consisting of TiCl₄/H₂O and MoOCl₄/H₂O subcycles. Two types of Ti_xMo_yO_z films were obtained in this work, where the ratio of subcycles was 1 : 1 (1Ti1MoO) and 1 : 7 (1Ti7MoO). The film growth rate was determined by spectroscopic ellipsometry and X-Ray reflectometry. The density and root-mean-square roughness of the films were also determined by X-Ray reflectometry. The composition of the films was determined by X-Ray photoelectron spectroscopy and found that the degree of oxidation of molybdenum in the MoO₃ and 1Ti7MoO films was +6, and in the 1Ti1MoO film, molybdenum was found in the oxidation state of +5 and +6. X-Ray diffraction analysis showed that the films had an amorphous structure.

The slowing down of the group velocity of light at the edges of the photonic band gap is one of the important optical effects observed in photonic crystals. In particular, the “slow light” effect is used in photocatalysis to increase the photocatalytic activity of semiconductors. In this work, anatase photonic crystals with different spectral positions of the photonic band gap (390–1283 nm, measured in water) were obtained. It is shown that if one of the photonic band gaps is located near the absorption edge of the semiconductor (410 nm), photonic crystal exhibits high photocatalytic activity in the photodegradation of methylene blue. At the same time, the photocatalytic activity of anatase photonic crystal increases by 30% when the photonic band gap of the third order rather than the first order is located near the absorption edge of the semiconductor.