Ukrainian Chemistry Journal

Journal Information
ISSN: 00416045
Total articles ≅ 85

Latest articles in this journal

, , Аnatoliy Sameliuk, Yuri Yurchenko
Ukrainian Chemistry Journal, Volume 86, pp 35-47; https://doi.org/10.33609/0041-6045.86.3.2020.35-47

Abstract:
Using the methods of physicochemical analysis (XRD, petrography, scanning electron microscopy analyses) phase equilibria were firstly investigated in the ternary system СeO2–La2O3–Eu2O3 system at 1250 ºС. It was established that in the system there exist fields of solid solutions based on cubic with fluorite-type structure (F) and cubic (С) and monoclinic (B) modification Eu2O3 and hexagonal (A) modification of La2O3. No new phases were found. The refined lattice parameters of the unit cells for solid solutions for the systems were determined. The cubic ceria-based solid solution has a fluorite-type structure and homogeneity field shows the maximum extension. It forms solid solutions of substitution type with phases of binary systems. The boundary of the homogeneity field of F-phase is curved from the center of triangle toward the CeO2 corner and passes through appropriate points in the binary CeО2-Eu2O3(100-69 mol % CeO2) and CeO2–La2O3 (100-51 mol% CeO2) systems. The lattice parameters for F phase vary from а = 0.5409 nm in pure СеО2toа = 0.5512 nm in two-phase sample (F + C) containing 55 mol % CeО2-22.5 mol % La2O3-22.5 mol % Eu2O3and to а = 0.5526 nm in three-phase sample (F + В + C) containing 40 mol % CeО2-30 mol % La2O3-30 mol % Eu2O3 and to а = 0.5532 nm in three-phase sample (А + F + В) containing 30 mol % CeО2-35 mol % La2O3-35 mol % Eu2O3along the section CeO2 ( 50 mol % La2O3-35 mol % Eu2O3). The lattice parameters for F phase vary from а = 0.5409 nm in pure СеО2 to а = 0.5444 nm nm in two-phase sample (F + C), containing 70 mol % CeО2-3 mol % La2O3-27 mol % Eu2O3and to а = 0.5465 nm in three-phase sample (F + В + C) containing 20 mol % CeО2-8 mol % La2O3-72 mol % Eu2O3. The homogeneity field of solid solution based on A-La2O3 extends to 17 mol % СеO2 and 20 mol % Eu2O3 in the corresponding binary systems and locates near the composition 5 mol % CeO2-90 mol % La2O3-5 mol % Eu2O3 on the section La2О3 - (50 mol % CeО2-50 mol % Eu2О3). The boundary of the homogeneity field of B- Eu2O3 phase passes through appropriate points in the binary CeО2-EuO3 (0-1 mol% CeO2) and–Eu2O3 (0-25 mol% La2O3) systems. The isothermal section of the CeO2– La2O3–Eu2O3 system at 1250°C contains four three-phase regions (A+F+B, F+B+C) and five two-phase regions (F+A, A+B, F+B, B+C, F+C).
Olga Chudinovych,
Ukrainian Chemistry Journal, Volume 86, pp 19-25; https://doi.org/10.33609/0041-6045.86.3.2020.19-25

Abstract:
Materials based on La2O3–Lu2O3 system are promising candidates for a wide range of applications, but the phase relationship has not been studied systematically previously. To address this challenge, the subsection of the phase diagram for 1500 and 1600 °C have been elucidated. The samples of different compositions have been prepared from nitrate acid solutions by evaporation, drying and heat treatment at 1100, 1500 and 1600 °C. The phase relations in the binary La2O3–Lu2O3 system at 1500 and 1600 °C were studied from the heat treated samples using X-ray diffraction analysis and scanning electron microscopy in the overall concentration range. The X–ray analysis of the samples was performed by powder method using DRON-3 at room temperature (CuKa radiation). It was established that in the binary La2O3–Lu2O3 system there exist fields of solid solutions based on hexagonal (A) modification of La2O3, cubic (C) modification of Lu2O3, and with perovskite–type structure of LaLuO3 (R) with rhombic distortions. The systematic study that covered whole composition range excluded formation of new phases. The systematic study that covered whole composition range excluded formation of new phases. The boundaries of mutual solubility and concentration dependences the lattice parameters for all phases have been determined. The solubility of Lu2O3 in the hexagonal А–lanthanum modification is ~ 9 mol. % at 1500 and 1600 °С. The solubility of La2O3 in the cubic C–Lu2O3 is ~ 4 mol. % at 1500 and 7 mol. % at 1600 °С.
, Dmytro Barbalat, Olena Guzenko, Mariya Zherebko,
Ukrainian Chemistry Journal, Volume 86, pp 26-34; https://doi.org/10.33609/0041-6045.86.3.2020.26-34

Abstract:
It was determined the chemico-analytical characteristics and composition of the complexes formed in the Mo(VI)–DOCh systems. The composition of the complexes (Mo(VI):DOCh = 1:2) was found by spectrophotometric methods (molar ratios, equilibrium shift). A probable complex chemistry was proposed based on a combination of spectrophotometric and mass- spectrometric data. It was shown that the MoO22+ cation acts as a complexing agent, and the ligand enters into the reaction in the form of an anhydrobase. It was found, that halogen-containing derivatives of MPDOCh form more intensely colored and stable complexes with Mo (VI) than MPDOCh, and the optimal pH of complexation shifts to a more acidic region. The study of the complexation of molybdenum(VI) with 6,7-dihydroxy-4-methyl-2-phenylchrome-nilium (MPDOCh) and its chlorine and bromine derivatives containing a halogen atom in 4th position in phenyl ring was shown that MoO22+ cation acts as a complexing agent, and the ligand involved into reaction in the form of an anhydrobase. The analytical characteristics of the resulting complexes were determined, and it was also noted that the halogen derivatives of MPDOCh form more intensely colored and stable complexes with Mo(VI).
Ukrainian Chemistry Journal, Volume 86, pp 48-60; https://doi.org/10.33609/0041-6045.86.3.2020.48-60

Abstract:
It is known that fulvic acids (FA) have a whole complex of therapeutic properties, but their widespread introduction into medical practice is limited by the dependence of the properties of the final product on the source of their extraction. In this regard, research aimed at developing experimental approaches for the production of synthetic substances that are similar in structure, physical, chemical and therapeutic properties to natural FA, but characterized by standardized and controlled parameters, is of interest. The purpose of the work was to develop a method of obtaining synthetic FA using as a precursor ellagitannins and lignin extracted from pomegranate peels and comprehensive study of their properties. As a result of the experiment and the analysis of the results it was found that the elagotanins and lignin contained in the peel of pomegranate can be used as a precursor to obtain synthetic FA. Comparative analysis of the elemental composition and spectral characteristics of synthetic FA with the literature data for natural FA allowed to ascertain the uniformity of their chemical structure. X-ray diffraction analysis of synthetic FA indicates their amorphous nature, which is typical of natural FA as well. The content of basic acid groups in the structure of synthetic FAs and their recovery capacity are calculated. In particular, the content of carboxyl groups is 2.7 ± 0.2 mmol/g, and the phenolic groups - 6.0 ± 0.1 mmol/g; the recovery capacity is 5.2 ± 0.3 mmol/g. The SEM images of the dried synthetic FA preparations show the uniformity of the powder particles obtained. However, unlike natural FA, synthetic analogues obtained by the developed method are characterized by controlled and reproducible properties, which greatly expands their use in medicine.
, , Olga Snurnikova, Elena Alekseeva, Tatyana Kirichenko
Ukrainian Chemistry Journal, Volume 86, pp 9-18; https://doi.org/10.33609/0041-6045.86.3.2020.9-18

Abstract:
Spectral-luminescent properties of a variety of carboxymethoxy-substituted p-tert-butyl-calix[4]arenes and their complexes with lanthanides (Nd, Er, Yb) that exhibit the 4f-luminescence in the IR-spectrum region have been investigated. The effect of substitution of hydrogen phenolic atoms by carboxymethoxy groups on the stability and spectral-luminescent characteristics of both the ligands and lanthanide complexes was analyzed. Thus, based on the combination of the results obtained by means of elemental analysis, mass spectrometry, IR and 1H NMR spectroscopy, and taking into account the data of pH-metric titration, spectrophotometric and luminescence measurements, it can be concluded that lanthanide ions form neutral complexes of 1:1 ratio with L1H4 - L4H4. This is explained by the presence of mobile hydrogen atoms of phenol and/or carboxyl groups in the molecules of these ligands. An increase in the number of donor substituents leads to changes in the number of solvent molecules in the series L3H4 < L1H4 < L2H4 < L4H4 from 0.8 to 2.4 for neodymium complexes, from 1.2 to 2.2 - for ytterbium complexes. Both the quantum yield and lifetime of the 4f-luminescence of the neodymium and ytterbium complexes and also the luminescence intensity of the erbium-containing compounds change in the same order.
Roman Selin, ,
Ukrainian Chemistry Journal, Volume 86, pp 3-8; https://doi.org/10.33609/0041-6045.86.3.2020.3-8

Abstract:
Reactions of azide-alkilic cycloaddition are well known since 1893. At the same time, with the elaboration of click chemistry, the techniques of labelling biological objects, particularly by fluorescent dyes, were widely developed. The use of fluorescent labels provides the ability to visually monitor the process streamlines hardware load and reduces research time. Fluorescein is among the fluorophores mostly used for labelling of biomolecules due to its high quantum yields and good stability in biological media. However, despite of commercial availability of fluorescein derivatives functionalized for use in click reactions, methods for their synthesis are virtually absent in the literature. Therefore, we have developed a reliable and effective methodic for the synthesis of functionalized fluoresceines for the use in the click reactions. Synthesis of diacetyl N-(4-azidobutyl)-fluoresceine-5(6)-carboxamide was performed in six stages, starting form resorcinol and trimellitic acid anhydride. The diacetylated analogue was synthesized for the click modifications in the “soft” conditions, since N-(4-azidobutyl)-fluorescein-5(6)-carboxamide is poorly soluble in the classic organic solvents. Proposed synthetic protocol allows to increase the yield of the final and intermediate compounds and to optimized the procedure of their isolation and purification.
Ukrainian Chemistry Journal, Volume 86, pp 111-122; https://doi.org/10.33609/0041-6045.86.2.2020.111-122

Abstract:
The rearrangement patterns of new 1,3-benzoxazines derivatives obtained by condensation of substituted salicylamides with cyclic ketones under the influence of Vilsmeier-Haack reagent has been studied. The influence of angel strain in a 4-membered spirocycle prevents the rearrangement of spiro [1,3-benzoxazine-2,1'-cyclobutan]-4(3H)-one under the action of a formylating agent. 1,3-Benzoxazines derivatives with ring sizes from 5- to 8-membered under the action of a formylating agent have formed formylxanthene derivative. Their formation reaction rate depends on the presence of electronegativity substituents at positions C-6 and C-8 of the aromatic cycle, as well as in the spiroring. In this work, we presented an effective method for the synthesis of formyl derivatives of xanthenes based on readily available salicylamide. It was found that (spiro[1,3-benzoxazine-2,1'-cyclobutan]-4(3H)-one) does not rearrange even under prolonged heating due to the spirocycle strain. The presence of bromine or iodine atoms at positions C-6 and C-8 of the aromatic cycle of 1,3-benzoxazines makes the reaction more difficult, which requires more harsh synthesis conditions.
, Yuriy Pirskyy, Andrii Kutsyi, Boris Danil’Tsev
Ukrainian Chemistry Journal, Volume 86, pp 63-77; https://doi.org/10.33609/0041-6045.86.2.2020.63-77

Abstract:
Aluminum is a promising metal for creating energy-storing substances (ESS) on its basis for hydrogen evolution from water as a result of its of activating aluminum and providing it with the ability to react with water, special attention is paid to methods of alloying it with additions of low-melting metals and alloys, in particular, the eutectic alloy of gallium, indium and tin is perspective alloy for alloying aluminum and obtaining ESS, capable of releasing hydrogen from water without additional heating. The temperature at which stable interaction of aluminum activated by low-melting metals and alloys with water begins to be determined by the temperature at which alloying metals on the surface of aluminum crystallites become liquid. The melting point of the four-component Ga61In25Sn13Zn1 eutectic is about 3 °C, what is about 8 °C lower than the melting point of the Ga-In-Sn eutectic. Therefore, in this work, aluminum was activated by the eutectic alloy of gallium, indium and tin, as well as zinc, and the regularities of the hydrolysis of the obtained EAPs were investigated. Comparative volumetric determinations of hydrogen, which was released during the hydrolysis of 95 wt.% Al + 5 wt.% Ga-In-Sn eutectic and 92 wt.% Al + 5 wt.% Ga-In-Sn eutectic + 3 wt.% Zn alloys, showed that the introduction of zinc into activated aluminum led to a significant acceleration of hydrogen evolution from water at low temperatures (25 and 40 °C). The effective rate constants of hydrolysis of the zinc-doped alloy, calculated using the modified Prout-Tompkins equation, were 1.33, 1.75, 2.19, and 2.58 min-1 at temperatures of 25, 40, 55, and 70 °C, respectively. The effective activation energy of the process, calculated from the temperature dependence of the effective rate constant, was 12.6 kJ·mol-1, which indicates diffuse control of the hydrolysis rate. An analysis of the X-ray diffraction pattern of the products of the hydrolysis of 92 wt.% Al + 5 wt.% Ga-In-Sn eutectic + 3 wt.% Zn alloy at the temperature of 55 °C showed that they contain boehmite, baerite and small amounts of alloying metals.
Sergiy Kemskiy, , Sergiy Sujkov, Oleksandr Yurchenko,
Ukrainian Chemistry Journal, Volume 86, pp 100-110; https://doi.org/10.33609/0041-6045.86.2.2020.100-110

Abstract:
The analysis of synthetic and biological importance of α-substituted β-prolines was conducted. Methods of synthesis of β-prolines and their esters, based on both intra- and intermolecular reactions of formation of functionalized pyrrolidinic cycle, as well as catalytic reduction of corresponding 2,3-substituted pyrroles and their dihydro derivatives, were systematized. The necessity of the hydrogenation process improvement of 2,3-di-substituted pyrroles using cheap catalysts was justified. The approach to α-substituted β-prolines (2-substituted pyrrolidine-3-carboxylic acids) was pro-posed, the first stage of which is N-Boc-protection of 2-substituted pyrrolidine-3-carboxylates with di-tert-butyl dicarbonate (Boc-anhydride) in the dichloromethane solution at the room temperature in presence of catalytic amounts of N,N-dime-thylaminopyridine. Obtained derivatives were subjected to hydrogenation in the autoclave at 45 atm. at 40 oC for 20 hours in presence of 10 % Pd/C catalyst. It was found, that reaction at such conditions proceeds with the full conversion of starting compounds and demonstrates high stereoselec-tivity and leads to the mixture of diastereomeric N-Boc-protected pyrrolidine-3-carboxylates of cis- and trans-configurations with corresponding contents of 84–87 % and 13–16 % according to NMR 1Н and chromato-mass spectra. The mild hydrolysis of isolated reaction mixtures in the water solution of lithium hydroxide followed by neutrali-zation and N-Boc-deprotection with 15 % hydrochloric acid allows isolating pure major diaste-reomers of α-substituted β-prolines with 69–74 % yields. Their trans-configuration was reliably confirmed by NMR 1Н spectroscopy using the NOESY experiment.
Ukrainian Chemistry Journal, Volume 86, pp 97-99; https://doi.org/10.33609/0041-6045.86.2.2020.97-99

Abstract:
The sensor is designed to measure the concentration of the dissolved oxygen in biological liquids, particularly in the blood stream or blood drop, and can be used in medical practice. Thus, in the treatment of hypoxia, which develops in the tissues due to the violation of the cell’s ability to absorb oxygen, it is necessary to control the part of the oxygen in the blood plasma that is not bound by hemoglobin. The same analysis is necessary for hyperbaric oxygenation of the blood in diseases of the lungs caused, particularly, in case of the coronavirus.......
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