Ukrainian Chemistry Journal

Journal Information
ISSN / EISSN: 27081281 / 2708129X
Total articles ≅ 133

Latest articles in this journal

Mariana Povidaichik, Oleksandr Shalimov, ,
Ukrainian Chemistry Journal, Volume 88, pp 34-40; https://doi.org/10.33609/2708-129x.88.09.2022.34-40

Abstract:
Amidines with a trichloromethyl group exhibit the properties of inotropic agents, which are used as scaffolds in synthesizing aza-hete­rocycles and ligands for complex formation. Functionalized amidines show anticancer, and antidiabetic activity, and are antihypertensive and antiparasitic agents. The synthesis of new functional derivatives of such amidines is definitely an urgent task. The introduction of an alkenyl substituent and several nucleophilic centers in the amidine creates prerequisites for electrophilic cyclization. This work aims to study the reactions of N-allyl-N-methyl-N'-(trimethylsilyl)-2,2,2-trichloroethanimidamide with tellurium halides. The starting N-allyl-N-methyl-N'-(trimethylsilyl)-2,2,2-trichloroethanimidamide was synthesized from N-allyl-N-methyl-­2,2,2-­trichloroethanimidamide by the action of trimethylsilyl chloride in the presence of triethylamine base. The reaction of N-­allyl-­N-methyl-N'-(trimethylsilyl)-2,2,2-trichloroethanimidamide with tellurium dioxide in hydrohalic acid was carried out while cooling to 0°C. Elemental analysis confirms that the electrophilic reagent is in its acidic form in the complex. The 1H NMR spectra of the obtained complexes indicate the absence of EVC - the spin pattern of the proton signals of the allylic substituent, characteristic of the starting compounds, is preserved, but the signals are shifted by 0.3–0.6 ppm. The absence of proton signals of the trimethyl salt substituent indicates the removal of imide protection under these conditions. The presence of a broade­ned singlet in a weak field indicates the pre­sence of acidic protons. Apparently, protonation does not take place on the alkenyl multiple bonds, but, presumably, on the imide nitrogen atom. Based on elemental analysis, the composition of the formed complex was determined: N-allyl-N-methyl-2,2,2-trichloroethanimidamidine: hexahalogenotelluric acid as 1:0.5, which contains 4 or 3 water molecules. So the interaction of N-allyl-N-methyl-N'-(trimethylsilyl)-2,2,2-trichloroethanimidamide with tellurium tetrahalides in a strongly acidic environment, tellurium- or proton-induced cyclization does not occur, but hexahalogeno­tellurate N-allyl-N-methyl-2,2,2-trichloro­etha­neimidamidinium regardless of the polarity of the solvent.
, Mariya Rusakova, Tamara Makotryk
Ukrainian Chemistry Journal, Volume 88, pp 3-24; https://doi.org/10.33609/2708-129x.88.09.2022.3-24

Abstract:
New complexes of 3d-metals (Co2+, Ni2+, Zn2+) with bis(phosphonomethyl)aminosuccinic acid (H6BPMAS) have been synthesized. The complexes were studied in aqueous solutions at ratios M2+:H6BPMAS = 1:1 in a wide pH range (1÷10). Regardless of the nature of the metal, the formation of complexes of the general composition [M(HnBPMAS)(OH)m] (n= 4÷0, m=1÷0) is shown. The stability constants of the formed differently protonated complexes are calculated and diagrams of their distribution are plotted. It is shown that the process of complexation takes place most completely in the region of pH>4. For all bis(phosphonomethyl)aminosuccinates of 3d metals, the dominance of the complex with one form of the ligand occurs in approximately the same pH ranges. A close order of change in the values of lgKst. complexes testifies to the same type of structure of their internal coordination sphere. Solid complexes of the composition Na4[MBPMAS]⋅4H2O were synthesized. Their composition, structure, and thermal characteristics were determined by the set of me­thods such as diffuse reflectance spectroscopy, IR spectroscopy, DTA and non-quantitative mass spectrometry. It is proved that the complexes have the structure of a distorted octahedron, in which the 3-d metal ions are bound to the oxygen atoms of the carboxyl and phosphonic groups and the tertiary nitrogen atom of the ligand. At the same time, two 5-membered (aminomethylenephosphonic and glycine) and one 6-membered (β-alanine) metallocycles are formed in bis(phosphonomethyl)aminosuccinates. The biological activity of H6BPMAS and its complexes with Ni(II) and Co(II) against non-pathogenic bacterial species of microorganisms Pseudomonas fluorescens and Pseudomonas aureofaciens was studied. The study of the activity of substances was carried out in a liquid sterile Hiss medium. The maxi­mum stimulating effect on the growth of bacterial cultures for the studied compounds was recorded at a concentration of 1 µM in 24 hours after the start of cultivation of mic­ro­organisms. The highest growth of microorganisms was recorded for metal complexes (50% Na4[CoBPMAS]·4H2O and 35% Na4[NiBPMAS]·4H2O). The maximum stimulating effect on the growth of bacterial cultures is shown by the Co(II) complex, which is able to initiate the synthesis of one of the most important growth hormones - heteroauxin.
Оleksandra Berezhnytska, Oleksandr Rohovtsov, ,
Ukrainian Chemistry Journal, Volume 88, pp 41-51; https://doi.org/10.33609/2708-129x.88.09.2022.41-51

Abstract:
Spherical silver nanoparticles were synthesized by the chemical condensation method using aloe vera or chamomile extracts as a reducing agent. Depending on the type of extracts and its concentration, the size of AgNpcs varied from 7 to 50 nm by simply adjusting the ratio of the starting reagents. These extracts show reducing properties due to the presence of carbonyl compounds in their composition, in particular organic acids. It is shown that regu­lation of concentrations and synthesis conditions allows control of particle size. A change in the synthesis conditions affects the position of the surface plasmon resonance band, and therefore the optical properties of the studied systems. It has been proven that the synthesized silver nanoparticles do not require additional stabilization. Agglomeration processes occur only with a significant increase in concentration and heating time.
Ukrainian Chemistry Journal, Volume 88, pp 25-33; https://doi.org/10.33609/2708-129x.88.09.2022.25-33

Abstract:
The technology of thermoelectric converters, based on the Peltier and Seebeck effects, provides a reversible process of convert in thermal and electrical energy. This opens up prospects for the creation of both thermoelectric coolers and thermoelectric generators. The most widely studied class of thermoelectric materials are complex chalcogenides. In recent years, copper-containing chalcogenides have been actively researched as new highly effective and ecologically friendly thermoelectric materials. The Cu–Sb–Se ternary system are characterized by the existence of three phases CuSbSe2, Cu3SbSe3 and Cu3SbSe4. Among these compounds, the Cu3SbSe3 phase is characterized by the lowest thermal conductivity. The synthesis of the Cu3SbSe3 polycrystalline alloy was carried out using high purity elementally components. The synthesis was carried out in vacuumed quartz ampoules by a one-temperature, two-stage process. Taking into account the incongruent melting of Cu3SbSe3, the single crystal growth was carried out by the method of vertical zone crystallization from a solution-melt in vacuumed conical quartz ampoules. As a result, the grown single crystal was dark gray color with metallic luster, without defects with length ~ 40 mm and diameter 12 mm. Obtained single crystalline sample of Cu3SbSe3 was investigated by DTA method. The heating curve contains one endothermic effect at 530°С, which corresponds to the process of peritectic decomposition of Cu3SbSe3. The effect corresponding to the melting of all components in the quartz container is not fixed. However, it is clearly visible on the cooling curve at 712 °С. The exothermic effect of crystallization of Cu3SbSe3 (503 °С) is clear and sharp and is observed with supercooling ΔТ = 27 °С. To confirm the single crystallinity of grown Cu3SbSe3 sample, an XRD analysis of the natural surface was carried out. The diffraction pattern shows two clear and narrow diffraction peaks corresponding to the (200) and (400) planes at angles of 22.27° and 45.42°, respectively. The crystal structure of the obtained Cu3SbSe3 single crystal was investigated by XRD analysis using the Rietveld full-profile refinement method. Established that Cu3SbSe3 crystallize in orthorhombic crystal system, SGPnma with lattice parameters: a = 7.9668 Å, b = 10.65870 Å, c = 6.8207 Å, Z = 4.
Mykola Koshel, Sergiy Koshel, Svitlana Korpach
Ukrainian Chemistry Journal, Volume 88, pp 79-96; https://doi.org/10.33609/2708-129x.88.08.2022.79-96

Abstract:
A new method of differential itn-metry has been developed for accurate determination of ion transfer numbers in materials with ion-exchange properties. Such materials include ion exchange membranes, liquid phase ion exchangers and ionic liquids, industrial ion exchange resins. The method is intended as an alternative simplified assessment of the functional properties of ion-exchange resins used in industrial technologies of water purification, water treatment, and extraction at enterprises of various industries. Such accurate information is obtained in special laboratories at enterprises by long-term and expensive physical and chemical methods. Transfer numbers give an indirect assessment of the quality of ion exchangers, but the method of differential itn-metry gives a result in a short 30-minute experiment on the electrolysis of a NaOH or NaCl solution in a three-chamber electrolyzer reactor. The electrolyzer-reactor contains an electrolyte volume of up to 40 cm3. The middle chamber of the electrolyzer-reactor has a variable width from 0.05 to 0.2 cm and an area of 10 cm2 perpendicular to the direction of the electric current. The primary result of each experiment was the functions of the electrolyte concentration dynamics C(τ) in the extreme cathode and anode chambers of the electrolyzer- reactor, where the dynamics of the readings of the flow resistometric sensor developed by us were recorded during the electrolysis process. The effective transfer number itn* was determined by mathematical data processing using a system of approximation functions. The method of differential itn-metry will be effective for other resins with amphoteric properties. The use of such a method could be used in works for the study of a wide range of problems in environmental monitoring and management of environmental projects.
Olha Kovalenko
Ukrainian Chemistry Journal, Volume 88, pp 66-78; https://doi.org/10.33609/2708-129x.88.08.2022.66-78

Abstract:
In the process of obtaining barium titanate by the Pechini method, a connection between the conditions of complexes precipitation and the nature of their thermal decomposition was established. X-ray phase analysis of thermally decomposed precursors showed that the formation of a single-phase system based on barium titanate can be achieved in the range of Ba/Ti ratio 0.96-1.01 at high reagent concentration and low solution pH during the precursor deposition process. On the basis of thermogravimetric analysis, a possible mechanism of precursor decomposition and its composition is assumed. It is shown that the number of hydroxide groups in the structure affects the crystallization mechanism, total mass loss, and the amount of water adsorbed on the surface. In particular, samples obtained at low solution pH have a minimal amount of hydroxyl groups and decompose according to a typical four-step mechanism of thermal decomposition of barium titanyl oxalate. Other samples contain hydro and carbo groups, which leads to an increase in the final decomposition temperature above 770 °C and a multistage decomposition process due to the difference in the activation energy of the nucleation of different phases. This, in turn, may determine the dominance of the nucleation process over the growth and nucleation of smaller crystallites, compared to the product of pure oxalate decomposition. On the one hand, the high content of chloride ions at the lowest pH promotes the crystallization of the product and the formation of additional nucleation centers from the phase of amorphous titanium dioxide. On the other hand, the formation of smaller crystallites occurs due to the absence of significant particle collisions in conditions of low concentration of the solution. On the basis of thermogravimetric analysis, it is shown that at high concentration, barium titanyl oxalate decomposes mainly by the mechanism of formation of intermediate oxycarbonates, and not barium carbonate and titanium dioxide. Thus, the optimization of the precursor precipitation parameters and the study of the barium titanate formation mechanism allow for better regulation of the composition and crystallite size of the final product.
Ukrainian Chemistry Journal, Volume 88, pp 97-105; https://doi.org/10.33609/2708-129x.88.08.2022.97-105

Abstract:
The surface structure and nature of the capacitance formation of RuO2/Ti and TiO2 /Ti films are discussed. The factors affecting the reversibility of the adsorption-desorption processes of oxygen on the surface of RuO2/Ti and TiO2 /Ti films are described. The influence of the geometry of the pore, ruthenium content, thickness of the films, and the capacitance value of oxide films was studied using electron microscopy and electrochemical impedance spectroscopy. The changes in pore content and their geometry depending on Ru concentration are fixed by electron microscopy. The changing capacitance and capacitance dispersion in a wide frequency range was used to obtain 3D images of the film's surface. A scheme of the adsorption-absorption ratio changing in relation to the pore’s structure of the films was proposed. The study of the composition, morphological structure and electrochemical behaviour of RuO2/Ti and TiO2 /Ti films determined the impact of the pore shape of surface films on the adsorption-absorption ratio of oxygen, which regulated technical data of sensors. By changing the capacitance and capacitance dispersion in a wide frequency range, it was proposed to obtain 3D images of the surface. It was found that decrease of DEL capacitance has following relationships: large V-shaped pores on the boundary of titanium base and oxide film and on the surface of film > small V-shaped pores on the boundary of titanium base and oxide film, and large pores on the surface of film > rectangular-shaped pores on the boundary of titanium base and oxide film and small V-shaped pores on the surface of film. The formation of the pore geometry and surface structure is dependent on the ration of ruthenium and the thickness of films. So, it is possible to change the morphological and electrochemical properties of sensors by the regulation of ruthenium content.
, Valeriia Zozuliia, Inna Tokmenko,
Ukrainian Chemistry Journal, Volume 88, pp 59-65; https://doi.org/10.33609/2708-129x.88.08.2022.59-65

Abstract:
The peculiarities of K2Gd(PO4)(MoO4) single crystal growth from combined phosphate-molybdate melts have been investigated. The formation regions of GdPO4, KGd(MoO4)2 and their cocrystallization fields with the mixed anionic compound potassium – gadolinium have been established. IR spect­roscopy showed that in all compounds molybdenum and phosphorus are in a tetrahedral environment, and the phase composition was confirmed by X-ray powder. Crystallization of the target compound K2Gd(PO4)(MoO4) is observed in the pseudobinary section K2Mo2O7-KPO3 orthiorombic system, space group Ibca, Z = 8, а = 19,694(4) Å, b = 12,260(3) Å, c = 6,961(3) Å. Double phosphate K3Gd(PO4)2 crystallizes in the form of colorless prismatic crystals from the melts with the initial ratio K/P = 1.7–3.3, which practically corresponds to the section K2MoO4 – K4P2O7. Phosphate GdPO4 crystallizes in the form of colorless prismatic crystals up to 0.1 mm in size at the maximum KPO3 content in the melt, which corresponds to K/P ratio = 0.20–0.50 and K/(Mo+P) = 0.25–0.33. Crystal-chemical criteria for the formation of mixed-anion-type layered frameworks, island structures, and three-dimensional frameworks based on mixed phosphate-molybdate systems and rare earth elements are proposed. The key factor in the formation of complex oxide compounds of rare earth elements from combined molybdate-phosphate melts is the ratio of K/Mo in the initial solution - melt: 1) at K/Mo = 0.5–1.1, LnPO4 orthophosphates are formed, which are characterized by a 3D framework on the basis of LnO7/LnO8poly­hedra condensed into a three-dimensional framework; at K/Mo = 1.2–1.5, mixed anionic compounds of the composition K2Ln(PO4)(MoO4) (Ln – Gd- Tb) with a layered structure are formed, where LnО8 forms zigzag chains; 3) at K/Mo = 1.6–3.0, double orthophosphates of the composition K3Ln(PO4)2 with an island structure are formed.
Liudmyla Sliusarchuk, Lidia Zheleznova, Serhii Kuleshov, Oleksandr Rohovtsov, , Borys Khomenko
Ukrainian Chemistry Journal, Volume 88, pp 3-15; https://doi.org/10.33609/2708-129x.88.07.2022.3-15

Abstract:
New heterometallic complexes of Сo(II) and Nd(III) with carboxylic acids (succinic, oxalic) and acetylacetone in the presence of phenanthroline or α,α'-dipyridyl have been synthesized. Their thermal properties and the ability to form complex oxides during thermal degradation have been studied. In the process of thermolysis of heterocomplexes, neodymium cobaltate NdCoO3 was obtained, which is confirmed by the results of X-ray powder diffraction. The research has established that the X-ray powder diffraction patterns of the products obtained by thermolysis of heterocomplex [Сo2Nd2(C4Н4O4)5·2Phen]·4Н2О to 1000 °С exhibits peaks at (2θ): 23.40, 33.74, 41.42, 48.32, 54.52, 59.94, 70.58°. This corresponds to the neodymium cobaltate NdCoO3. Neodymium cobaltate crystallizes in the cubic crystal system. The sample was obtained without extraneous phases inclusions. For the samples obtained by the termolysis of he­te­rocomplexes [Сo2Nd2(C2O4)5·2Phen]·4Н2О and NdCo(AA)5·2α,α'-dipy, in addition to the complex oxide NdCoO3, peaks of Nd2O3 were recorded, which crystallizes in the hexa­gonal crystal system. The X-ray powder diffraction patterns show peaks with 2θ values: 26.92, 29.75, 30.77, 40.54, 47.53, 53.63, 57.08°. The phase ratio of NdCoO3/Nd2O3 after termolysis for the sample of CoNd(AA)5·2α,α'-dipy is ~ 68.9/31.1%; for the sample of [Сo2Nd2(C2O4)5·2Phen]·4Н2О is ~ 50/50%; for the sample of [Сo2Nd2(C4Н4O4)5·2Phen]·4Н2О is NdCoO3 ~ 100%. The average crystallites size of complex oxides was calculated using the Scherer formula. It has been showed that neodymium cobaltate has an average particle size of ~33 nm, regardless of the complex precursor from which it was formed during thermolysis. The catalytic effect of neodymium cobaltates in the hydrogen peroxide decomposition reaction was studied. It was shown that all samples of complex oxides showed a quite high cataly­tic activity in the all of experiments in the hydro­gen peroxide decomposition reactions.
Tetiana Plutenko, , Oleksandr Fedorchuk, , , Boris Khomenko
Ukrainian Chemistry Journal, Volume 88, pp 16-28; https://doi.org/10.33609/2708-129x.88.07.2022.16-28

Abstract:
Solid solutions of nickel-zinc ferrites ZnxNi1-xFe2O4 were synthesized by two different methods: synthesis in microemulsions and by stepwise precipitation. The properties of the resulted nano-sized particles synthesized by two different methods were compared. It was found that the increase in zinc content leads to an increase in the lattice parameters. During the synthesis by the method of microemulsions, the temperature of a single-phase product formation is 400 °C, while by the method of precipitation, a single-phase product formation begins at 600 °C. It was shown that the materials synthesized by both methods have similar unit cell parameters. The average size of ferrite nanoparticles synthesized in microemulsions is smaller, lattice strain is higher compared to ferrites synthesized by stepwise precipitation. Also, lower treatment temperatures provide higher stoichiometry, and homogeneity of materials while magnetization difference is negligible. The particles of the obtained powders have high saturation magnetization Ms = 45.6 Am2/kg for synthesis from microemulsions and Ms = 44.8 Am2/kg for co-precipitated samples, the low coercive force Hc = 1.3 kA/m and Hc = 3 kA/m, respectively. Changes made make synthesized particles more applicable in film deposition, and manufacturing of high-quality magnetic coatings.
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