Pub Date : 2022-01-21DOI: 10.33609/2708-129x.87.11.2021.109-120
A. Ostroverkh, Y. Ostroverkh, L. Kovalenko, A. Samelyuk, O. Bezdorozhev, O. Vasylyev, Y. Solonin
The work is devoted to zinc oxide and the prospects of its use for the needs of hydrogen energy. The influence of zinc oxide on electrolyte materials for ceramic fuel cells is determined. The properties of ceramics based on 8YSZ were investigated by adding 0.5 wt.% nanopowder of zinc oxide according to the method of the research of zinc oxide ceramics. The electrical conductivity of 8YSZ in an oxygen atmosphere shows a better conductivity characteristic, but 8YSZ-ZnO ceramics have better mechanical properties and higher reactivity in real fuel cell conditions. It was found that zinc oxide has a positive effect on the open voltage of SOFC in the temperature range from 320 °C to 600 °C. The maximum value of the open voltage for the electrolyte 8YSZ-ZnO was obtained at a temperature of 520 °C with a value of 1.02 V, in turn for the electrolyte of pure 8YSZ the maximum value was 0.92 V at a temperature of 600 °C. The small amount of data on the use of pure zinc oxide as an electrolyte opens up opportunities for thorough analysis and determination of optimal technological parameters that will accelerate the introduction of hydrogen energy technologies with operating temperatures below 600 ºC. From a brief overview of existing zinc oxide-based materials in fuel cells, materials with mixed conductivity and low sintering temperatures are the most promising and effective for implementation in real systems. Data on the effect of sintering temperature on the porosity of ceramics with 8YSZ-ZnO and 8YSZ determined that the porosity of samples of both types decreases significantly with increasing sintering temperature of powders, but the addition of zinc oxide to 8YSZ-ZnO composite allows to obtain dense ceramics at temperatures below 100 °C than for pure 8YSZ. Regarding the strength of 8YSZ-ZnO ceramics, it increases with increasing sintering temperature and has higher values relative to pure 8YSZ. Both porosity and strength change rapidly in the range of 1200–1300 °C and slowly in the range of 1300–1400 °C, due to the sintering temperature of ceramics made of pure zinc oxide 1100–1200 °C. Improving the sintering conditions of ceramics and mechanical properties reveal its advantage in the addition of zinc oxide.
{"title":"FEATURES OF ZnO APPLICATION IN THE STRUCTURE OF HYDROGEN FUEL CELL","authors":"A. Ostroverkh, Y. Ostroverkh, L. Kovalenko, A. Samelyuk, O. Bezdorozhev, O. Vasylyev, Y. Solonin","doi":"10.33609/2708-129x.87.11.2021.109-120","DOIUrl":"https://doi.org/10.33609/2708-129x.87.11.2021.109-120","url":null,"abstract":"The work is devoted to zinc oxide and the prospects of its use for the needs of hydrogen energy. The influence of zinc oxide on electrolyte materials for ceramic fuel cells is determined. The properties of ceramics based on 8YSZ were investigated by adding 0.5 wt.% nanopowder of zinc oxide according to the method of the research of zinc oxide ceramics. The electrical conductivity of 8YSZ in an oxygen atmosphere shows a better conductivity characteristic, but 8YSZ-ZnO ceramics have better mechanical properties and higher reactivity in real fuel cell conditions. \u0000It was found that zinc oxide has a positive effect on the open voltage of SOFC in the temperature range from 320 °C to 600 °C. The maximum value of the open voltage for the electrolyte 8YSZ-ZnO was obtained at a temperature of 520 °C with a value of 1.02 V, in turn for the electrolyte of pure 8YSZ the maximum value was 0.92 V at a temperature of 600 °C. The small amount of data on the use of pure zinc oxide as an electrolyte opens up opportunities for thorough analysis and determination of optimal technological parameters that will accelerate the introduction of hydrogen energy technologies with operating temperatures below 600 ºC. From a brief overview of existing zinc oxide-based materials in fuel cells, materials with mixed conductivity and low sintering temperatures are the most promising and effective for implementation in real systems. \u0000Data on the effect of sintering temperature on the porosity of ceramics with 8YSZ-ZnO and 8YSZ determined that the porosity of samples of both types decreases significantly with increasing sintering temperature of powders, but the addition of zinc oxide to 8YSZ-ZnO composite allows to obtain dense ceramics at temperatures below 100 °C than for pure 8YSZ. Regarding the strength of 8YSZ-ZnO ceramics, it increases with increasing sintering temperature and has higher values relative to pure 8YSZ. Both porosity and strength change rapidly in the range of 1200–1300 °C and slowly in the range of 1300–1400 °C, due to the sintering temperature of ceramics made of pure zinc oxide 1100–1200 °C. Improving the sintering conditions of ceramics and mechanical properties reveal its advantage in the addition of zinc oxide.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78804917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-21DOI: 10.33609/2708-129x.87.11.2021.63-96
L. Koval, E. Trunova, V. Pekhnyo
The review considers the main stages of development of the chemistry of coordination compounds at the Institute of General and Inorganic Chemistry. VI Vernadsky National Academy of Sciences of Ukraine on the occasion of the 90th anniversary of its founding. An overview of complex compounds of p, d, f-metals with different classes of ligands (inorganic and organic), features of their synthesis, study of the structure and properties of the obtained compounds, contains current material on the use of synthesized complexes to create functional materials for different purposes. Methods of synthesis have been developed, dozens of new coordination compounds with derivatives of hydrazones, amines, azomethanes, and thiosemicarbazones have been synthesized and isolated in the individual state. Their composition, structure and physicochemical properties are determined. The general regularities that take place in the process of complexation of metals with ligands, as well as factors influencing the composition, structure and physicochemical properties of the obtained coordination compounds are established. For the long history of the Institute has accumulated a huge amount of material on the problems of modern coordination chemistry. Significant research in this area belongs to Ukrainian scientists who have worked long and fruitfully at the Institute: A.K. Babko, К.B. Yatsimirsky, Ya.A. Fialkov, I.A. Sheka, S.V. Volkov, N.A. Kostromina, and who created scientific schools, known not only in Ukraine but also abroad. To date, the attention of scientists of the Institute has shifted from classical monomeric to bigeteronuclear, polynuclear, multiligand complexes, which is primarily due to intensive research of new functional materials: optical and magnetic, biologically active substances, as well as effective adsorbents, chemical sensors, catalysts, catalysts, catalysts and biochemical processes.
{"title":"DEVELOPMENT OF RESEARCH OF CHEMISTRY OF COORDINATION COMPOUNDS IN V.I. VERNADSKY INSTITUTE OF GENERAL AND INORGANIC CHEMISTRY NAS OF UKRAINE: FROM THE 30'S TWENTIETH CENTURY (part 2)","authors":"L. Koval, E. Trunova, V. Pekhnyo","doi":"10.33609/2708-129x.87.11.2021.63-96","DOIUrl":"https://doi.org/10.33609/2708-129x.87.11.2021.63-96","url":null,"abstract":"The review considers the main stages of development of the chemistry of coordination compounds at the Institute of General and Inorganic Chemistry. VI Vernadsky National Academy of Sciences of Ukraine on the occasion of the 90th anniversary of its founding. An overview of complex compounds of p, d, f-metals with different classes of ligands (inorganic and organic), features of their synthesis, study of the structure and properties of the obtained compounds, contains current material on the use of synthesized complexes to create functional materials for different purposes. Methods of synthesis have been developed, dozens of new coordination compounds with derivatives of hydrazones, amines, azomethanes, and thiosemicarbazones have been synthesized and isolated in the individual state. Their composition, structure and physicochemical properties are determined. The general regularities that take place in the process of complexation of metals with ligands, as well as factors influencing the composition, structure and physicochemical properties of the obtained coordination compounds are established. \u0000For the long history of the Institute has accumulated a huge amount of material on the problems of modern coordination chemistry. Significant research in this area belongs to Ukrainian scientists who have worked long and fruitfully at the Institute: A.K. Babko, К.B. Yatsimirsky, Ya.A. Fialkov, I.A. Sheka, S.V. Volkov, N.A. Kostromina, and who created scientific schools, known not only in Ukraine but also abroad. To date, the attention of scientists of the Institute has shifted from classical monomeric to bigeteronuclear, polynuclear, multiligand complexes, which is primarily due to intensive research of new functional materials: optical and magnetic, biologically active substances, as well as effective adsorbents, chemical sensors, catalysts, catalysts, catalysts and biochemical processes.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77501528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-21DOI: 10.33609/2708-129x.87.12.2021.97-108
I. Novoselova, S. Kuleshov, A. Omel’chuk, V. Bykov, O. Fesenko
Electrocatalysis is one of the actively developing fields of application of tungsten carbides. For the synthesis of catalytically active carbides (materials with a large specific surface area, small particle size and structural defects) a large number of different technologies are being developed in the world. The method of high-temperature electrochemical synthesis is promising one. For its successful realization, it is necessary to study in detail the electrochemical behavior of each carbide component (tungsten and carbon) and the features of their partial and joint discharge. The aim of this paper is a voltammetric study of the partial and joint electroreduction of Na2W2O7 and Li2CO3 in molten NaCl–KCl electrolyte under CO2 pressure at a temperature of 750 °C. As a result of research, it was found that in the system Na,K|Cl–Na2W2O7–Li2CO3–CO2 joint reduction of tungsten carbide synthesis components occurs from lithium complexes of tungstate (LixWO4)2-x and carbonate- (LixCO3)2-x anions at potentials -1.65 – -1.8 V. Introduction of СО2 into the system (creation of its excess pressure in the cell) is necessary for the binding of oxide anions O2-, released during the discharge of anionic complexes, into a carbonate complex. The released oxide anion in the near-electrode layer inhibits the cathodic process. Also, a necessary condition for the sustainability production of tungsten monocarbide WC is the presence of free carbon, which is formed during the decomposition of CO2. Nanosized composites of tungsten carbides with free carbon WC/C (5 wt%) were obtained by potentiostatic electrolysis at a potential of -1.8 V as a cathode product. The properties of the obtained compounds were analyzed by XRD, SEM, BET, and Raman spectroscopy. Tungsten carbide has a particle size of ~ 10 nm and consists of hollow spherical structures. The synthesized composite is mesoporous material with a specific surface area of ~ 140 m2/g. The properties of the synthesized composite, namely: structural defects, the presence of free carbon, spherical morphology, nanometer size and high specific surface area, make it possible to use it as an effective electrocatalyst, for example, in the reaction of hydrogen evolution in acidic aqueous solutions.
{"title":"ELECTROREDUCTION OF DITUNGSTATE AND CARBONATE ANIONS IN CHLORIDE MELT","authors":"I. Novoselova, S. Kuleshov, A. Omel’chuk, V. Bykov, O. Fesenko","doi":"10.33609/2708-129x.87.12.2021.97-108","DOIUrl":"https://doi.org/10.33609/2708-129x.87.12.2021.97-108","url":null,"abstract":"Electrocatalysis is one of the actively developing fields of application of tungsten carbides. For the synthesis of catalytically active carbides (materials with a large specific surface area, small particle size and structural defects) a large number of different technologies are being developed in the world. The method of high-temperature electrochemical synthesis is promising one. For its successful realization, it is necessary to study in detail the electrochemical behavior of each carbide component (tungsten and carbon) and the features of their partial and joint discharge. The aim of this paper is a voltammetric study of the partial and joint electroreduction of Na2W2O7 and Li2CO3 in molten NaCl–KCl electrolyte under CO2 pressure at a temperature of 750 °C. \u0000As a result of research, it was found that in the system Na,K|Cl–Na2W2O7–Li2CO3–CO2 joint reduction of tungsten carbide synthesis components occurs from lithium complexes of tungstate (LixWO4)2-x and carbonate- (LixCO3)2-x anions at potentials -1.65 – -1.8 V. Introduction of СО2 into the system (creation of its excess pressure in the cell) is necessary for the binding of oxide anions O2-, released during the discharge of anionic complexes, into a carbonate complex. The released oxide anion in the near-electrode layer inhibits the cathodic process. Also, a necessary condition for the sustainability production of tungsten monocarbide WC is the presence of free carbon, which is formed during the decomposition of CO2. \u0000Nanosized composites of tungsten carbides with free carbon WC/C (5 wt%) were obtained by potentiostatic electrolysis at a potential of -1.8 V as a cathode product. The properties of the obtained compounds were analyzed by XRD, SEM, BET, and Raman spectroscopy. Tungsten carbide has a particle size of ~ 10 nm and consists of hollow spherical structures. The synthesized composite is mesoporous material with a specific surface area of ~ 140 m2/g. \u0000The properties of the synthesized composite, namely: structural defects, the presence of free carbon, spherical morphology, nanometer size and high specific surface area, make it possible to use it as an effective electrocatalyst, for example, in the reaction of hydrogen evolution in acidic aqueous solutions.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77557710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-24DOI: 10.33609/2708-129x.87.11.2021.45-54
O. Ivanenko, T. Pavlenko
Based on studies of the decomposition of petalite ore, the hydrothermal method for the extraction of lithium and aluminum compounds from lithium aluminosilicate Li[AlSi4O10] (petalite) has been developed. The studied sample of ore contains, wt. %: Li2O – 0.75 and Al2O3 – 14.65. For unenriched petalite ore with low lithium content, it is proposed to use the hydrochemical method of aluminosilicate processing – Ponomarev – Sazhin method. According to this method, the decomposition of ore is carried out directly in autoclaves by chemical interaction of ore components with NaOH solution in the presence of calcium oxide. The conditions (high temperature and pressure) for the destruction of petalite and the transition of lithium into the liquid phase are created exactly in the hydrothermal process. In this case, lithium and aluminum compounds pass into the solution, and calcium and silicon form a partially soluble compound in the solid phase – sodium-calcium hydrosilicateNa2O·2CaO·2SiO2·2H2O. The degree of extraction of lithium reaches 89–94 %, aluminum reaches 77–95 % within 1 hour at a temperature of 240–280 °C, given caustic modulus 14–18, the concentration of the initial solution of 400–450 g/dm3 of Na2O and the ratio of CaO : SiO2 = 1 : 1 in the reaction mixture. Aluminate or lithium carbonate and other compounds can be obtained from an aluminate solution containing 1.5–2.5 g/dm3 of Li2O and 32–44 g/dm3 of Al2O3. The solid phase formed as a result of decomposition, with a high degree of extraction of lithium from the ore contains a small amount of Li2O in its composition and therefore can be used in the cement industry. Depending on the quality of the decomposed raw material, the course of the hydrothermal process is influenced by a set of factors. With a small content of lithium and aluminum in the ore, the caustic modulus of aluminate solutions (αк = 1,645*Na2O/Al2O3) formed after decomposition is important. Its calculation is required in order to determine the amount of alkaline solution of the required concentration to ensure almost complete decomposition of the ore. This value should be higher the lower the decomposition temperature and the concentration of the initial solution to achieve the same degree of recovery of useful components in the liquid phase. With the same caustic modulus, the efficiency of ore decomposition increases significantly with increasing process temperature and increasing the concentration of the initial solution. This can be seen in the values of the degree of extraction of aluminum, which increases by 12 % with increasing temperature from 240 to 280 °C, while the extraction of lithium remains practically unchanged.
{"title":"HYDROTHERMAL EXTRACTION OF LITHIUM COMPOUNDS FROM PETALITE Li[AlSi4O10]","authors":"O. Ivanenko, T. Pavlenko","doi":"10.33609/2708-129x.87.11.2021.45-54","DOIUrl":"https://doi.org/10.33609/2708-129x.87.11.2021.45-54","url":null,"abstract":"Based on studies of the decomposition of petalite ore, the hydrothermal method for the extraction of lithium and aluminum compounds from lithium aluminosilicate Li[AlSi4O10] (petalite) has been developed. The studied sample of ore contains, wt. %: Li2O – 0.75 and Al2O3 – 14.65. For unenriched petalite ore with low lithium content, it is proposed to use the hydrochemical method of aluminosilicate processing – Ponomarev – Sazhin method. According to this method, the decomposition of ore is carried out directly in autoclaves by chemical interaction of ore components with NaOH solution in the presence of calcium oxide. The conditions (high temperature and pressure) for the destruction of petalite and the transition of lithium into the liquid phase are created exactly in the hydrothermal process. In this case, lithium and aluminum compounds pass into the solution, and calcium and silicon form a partially soluble compound in the solid phase – sodium-calcium hydrosilicateNa2O·2CaO·2SiO2·2H2O. The degree of extraction of lithium reaches 89–94 %, aluminum reaches 77–95 % within 1 hour at a temperature of 240–280 °C, given caustic modulus 14–18, the concentration of the initial solution of 400–450 g/dm3 of Na2O and the ratio of CaO : SiO2 = 1 : 1 in the reaction mixture. Aluminate or lithium carbonate and other compounds can be obtained from an aluminate solution containing 1.5–2.5 g/dm3 of Li2O and 32–44 g/dm3 of Al2O3. The solid phase formed as a result of decomposition, with a high degree of extraction of lithium from the ore contains a small amount of Li2O in its composition and therefore can be used in the cement industry. \u0000Depending on the quality of the decomposed raw material, the course of the hydrothermal process is influenced by a set of factors. With a small content of lithium and aluminum in the ore, the caustic modulus of aluminate solutions (αк = 1,645*Na2O/Al2O3) formed after decomposition is important. Its calculation is required in order to determine the amount of alkaline solution of the required concentration to ensure almost complete decomposition of the ore. This value should be higher the lower the decomposition temperature and the concentration of the initial solution to achieve the same degree of recovery of useful components in the liquid phase. With the same caustic modulus, the efficiency of ore decomposition increases significantly with increasing process temperature and increasing the concentration of the initial solution. This can be seen in the values of the degree of extraction of aluminum, which increases by 12 % with increasing temperature from 240 to 280 °C, while the extraction of lithium remains practically unchanged.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74721274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-24DOI: 10.33609/2708-129x.87.11.2021.21-44
E. Trunova, L. Koval, V. Pekhnyo
The review considers the main stages of development of the chemistry of coordination compounds at the Institute of General and Inorganic Chemistry. VI Vernadsky National Academy of Sciences of Ukraine on the occasion of the 90th anniversary of its founding. An overview of complex compounds of p, d, f-metals with different classes of ligands (inorganic and organic), features of their synthesis, study of the structure and properties of the obtained compounds, contains current material on the use of synthesized complexes to create functional materials for different purposes. Methods of synthesis have been developed, dozens of new coordination compounds with derivatives of hydrazones, amines, azomethanes, and thiosemicarbazones have been synthesized and isolated in the individual state. Their composition, structure and physicochemical properties are determined. The general regularities that take place in the process of complexation of metals with ligands, as well as factors influencing the composition, structure and physicochemical properties of the obtained coordination compounds are established. For the long history of the Institute has accumulated a huge amount of material on the problems of modern coordination chemistry. Significant research in this area belongs to Ukrainian scientists who have worked long and fruitfully at the Institute: A.K. Babko, K.B. Yatsimirsky, Ya.A. Fialkov, I.A. Sheka, S.V. Volkov, N.A. Kostromina, and who created scientific schools, known not only in Ukraine but also abroad. To date, the attention of scientists of the Institute has shifted from classical monomeric to bigeteronuclear, polynuclear, multiligand complexes, which is primarily due to intensive research of new functional materials: optical and magnetic, biologically active substances, as well as effective adsorbents, chemical sensors, catalysts, catalysts, catalysts and biochemical processes.
{"title":"DEVELOPMENT OF RESEARCH OF CHEMISTRY OF COORDINATION COMPOUNDS IN V.I. VERNADSKY INSTITUTE OF GENERAL AND INORGANIC CHEMISTRY NAS OF UKRAINE: FROM THE 30'S TWENTIETH CENTURY(part1)","authors":"E. Trunova, L. Koval, V. Pekhnyo","doi":"10.33609/2708-129x.87.11.2021.21-44","DOIUrl":"https://doi.org/10.33609/2708-129x.87.11.2021.21-44","url":null,"abstract":"The review considers the main stages of development of the chemistry of coordination compounds at the Institute of General and Inorganic Chemistry. VI Vernadsky National Academy of Sciences of Ukraine on the occasion of the 90th anniversary of its founding. An overview of complex compounds of p, d, f-metals with different classes of ligands (inorganic and organic), features of their synthesis, study of the structure and properties of the obtained compounds, contains current material on the use of synthesized complexes to create functional materials for different purposes. Methods of synthesis have been developed, dozens of new coordination compounds with derivatives of hydrazones, amines, azomethanes, and thiosemicarbazones have been synthesized and isolated in the individual state. Their composition, structure and physicochemical properties are determined. The general regularities that take place in the process of complexation of metals with ligands, as well as factors influencing the composition, structure and physicochemical properties of the obtained coordination compounds are established. \u0000For the long history of the Institute has accumulated a huge amount of material on the problems of modern coordination chemistry. Significant research in this area belongs to Ukrainian scientists who have worked long and fruitfully at the Institute: A.K. Babko, K.B. Yatsimirsky, Ya.A. Fialkov, I.A. Sheka, S.V. Volkov, N.A. Kostromina, and who created scientific schools, known not only in Ukraine but also abroad. To date, the attention of scientists of the Institute has shifted from classical monomeric to bigeteronuclear, polynuclear, multiligand complexes, which is primarily due to intensive research of new functional materials: optical and magnetic, biologically active substances, as well as effective adsorbents, chemical sensors, catalysts, catalysts, catalysts and biochemical processes.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77561864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-26DOI: 10.33609/2708-129x.87.10.2021.103-115
S. Smola, N. Rusakova, O. Alekseeva, S. Basok, T. Kirichenko, O. Korovin, O. Malinka, N. Semenishyn
Lanthanide complexes with calix[4]arenes lower rim substituted with two azacrown ether fragments are reported. The size of the substituent cavity varied from 4 to 6 heteroatoms. The complexes were analyzed by means of IR, NMR, ESI mass spectroscopy. It is assumed that the coordination of Ln(III) ions occurs through the donor atoms of the lower rim; the counter anion and solvent molecule are also coordinated. Lanthanide-centered characteristic luminescence was observed in Eu(III), Tb(III) and Yb(III) complexes. The most efficient 4f-luminescence is observed for terbium-containing complexes with benzo-crown-derived ligands. The pathways of the sensitization of 4f-luminescence are discussed.
{"title":"STRUCTURE AND SPECTRAL-LUMUINESCENT PROPERTIES OF LANTHANIDE-CONTAINING COMPLEXES WITH AZACROWN CALIXARENES","authors":"S. Smola, N. Rusakova, O. Alekseeva, S. Basok, T. Kirichenko, O. Korovin, O. Malinka, N. Semenishyn","doi":"10.33609/2708-129x.87.10.2021.103-115","DOIUrl":"https://doi.org/10.33609/2708-129x.87.10.2021.103-115","url":null,"abstract":"Lanthanide complexes with calix[4]arenes lower rim substituted with two azacrown ether fragments are reported. The size of the substituent cavity varied from 4 to 6 heteroatoms. The complexes were analyzed by means of IR, NMR, ESI mass spectroscopy. It is assumed that the coordination of Ln(III) ions occurs through the donor atoms of the lower rim; the counter anion and solvent molecule are also coordinated. Lanthanide-centered characteristic luminescence was observed in Eu(III), Tb(III) and Yb(III) complexes. The most efficient 4f-luminescence is observed for terbium-containing complexes with benzo-crown-derived ligands. The pathways of the sensitization of 4f-luminescence are discussed.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82252391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-26DOI: 10.33609/2708-129x.87.10.2021.63-73
N. Mchedlov-Petrossyan, Mykyta O Marfunin, V. Klochkov, Petro Radionov
This article is devoted to the synthesis and characterization of the hydrosol of C70 of the son/nC70 type and to its coagulation by sodium chloride and cetyltrimethylammonium bromide (CTAB). At C70 concentration of 3.3×10–6 M, the electrokinetic potential is ζ= –40 ± 4 mV, the particle size expressed as Zeta-average is 97±3 nm; at higher C70 concentrations, 1.7×10–5 and 6.9×10–5 M, the size stays the same: 99 – 100 nm. The critical concentration of coagulation (CCC) values, were determined using the diameter increasing rate (DIR) on NaCl concentration. The CCCs are concentration-dependent: 250, 145, and 130 mM at C70 concentrations 3.3×10–6, 1.7×10–5, and 6.9×10–5 M, respectively. The CCC for the CTAB surfactant is much lower, about 5×10–3 mM. At 0.02 mM CTAB, however, the overcharging up to ζ = + 40 mV and stabilization of the colloidal particles take place. Interpretation of the hydrosol coagulation by NaCl using the Derjaguin–Landau–Verwey–Overbeek theory makes it possible to determine the Hamaker constant of the C70–C70 interaction in vacuum, if only electrostatic repulsion and molecular attraction are taking into account: AFF ≈ 7×10–20 J. On the other hand, if we use the value AFF = (16.0–16.6)×10–20 J, obtained earlier in the study of organosols, then the data for hydrosols can be explained only by the introduction of an additional type of interactions. Following the terms of Churaev and Derjaguin, one should take into account the structural contribution to the interaction energy, which stabilizes the hydrosol.
{"title":"HYDROSOL OF C70 FULLERENE: SYNTHESIS AND STABILITY IN ELECTROLYTIC SOLUTIONS","authors":"N. Mchedlov-Petrossyan, Mykyta O Marfunin, V. Klochkov, Petro Radionov","doi":"10.33609/2708-129x.87.10.2021.63-73","DOIUrl":"https://doi.org/10.33609/2708-129x.87.10.2021.63-73","url":null,"abstract":"This article is devoted to the synthesis and characterization of the hydrosol of C70 of the son/nC70 type and to its coagulation by sodium chloride and cetyltrimethylammonium bromide (CTAB). At C70 concentration of 3.3×10–6 M, the electrokinetic potential is ζ= –40 ± 4 mV, the particle size expressed as Zeta-average is 97±3 nm; at higher C70 concentrations, 1.7×10–5 and 6.9×10–5 M, the size stays the same: 99 – 100 nm. The critical concentration of coagulation (CCC) values, were determined using the diameter increasing rate (DIR) on NaCl concentration. The CCCs are concentration-dependent: 250, 145, and 130 mM at C70 concentrations 3.3×10–6, 1.7×10–5, and 6.9×10–5 M, respectively. The CCC for the CTAB surfactant is much lower, about 5×10–3 mM. At 0.02 mM CTAB, however, the overcharging up to ζ = + 40 mV and stabilization of the colloidal particles take place. Interpretation of the hydrosol coagulation by NaCl using the Derjaguin–Landau–Verwey–Overbeek theory makes it possible to determine the Hamaker constant of the C70–C70 interaction in vacuum, if only electrostatic repulsion and molecular attraction are taking into account: AFF ≈ 7×10–20 J. On the other hand, if we use the value AFF = (16.0–16.6)×10–20 J, obtained earlier in the study of organosols, then the data for hydrosols can be explained only by the introduction of an additional type of interactions. Following the terms of Churaev and Derjaguin, one should take into account the structural contribution to the interaction energy, which stabilizes the hydrosol.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77357943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-26DOI: 10.33609/2708-129x.87.10.2021.74-89
Dasha Asieieva
The review describes modern physicochemical systems based on complex compounds with organic ligands, which may have fluorescent properties when interacting with metal ions or proteins. Modern methods of synthesis of these compounds and their use in physical-chemical methods of analysis are given. Approaches to detecting the content of metals and proteins using the fluorescent properties of morin complex compounds are considered. Areas of use of the effects of amplification and quenching of fluorescence for the determination of organic compounds and metal ions, especially in the presence of DNA and RNA of different biological origin are described. The influence of surfactants on the fluorescence intensity of complexes with morin was analyzed separately.
{"title":"METHODS OF SYNTHESIS AND FEATURES OF USING SYSTEMS BASED ON MORIN-METAL COMPLEXES IN FLUORESCENT ANALYSIS METHODS","authors":"Dasha Asieieva","doi":"10.33609/2708-129x.87.10.2021.74-89","DOIUrl":"https://doi.org/10.33609/2708-129x.87.10.2021.74-89","url":null,"abstract":"The review describes modern physicochemical systems based on complex compounds with organic ligands, which may have fluorescent properties when interacting with metal ions or proteins. Modern methods of synthesis of these compounds and their use in physical-chemical methods of analysis are given. Approaches to detecting the content of metals and proteins using the fluorescent properties of morin complex compounds are considered. Areas of use of the effects of amplification and quenching of fluorescence for the determination of organic compounds and metal ions, especially in the presence of DNA and RNA of different biological origin are described. The influence of surfactants on the fluorescence intensity of complexes with morin was analyzed separately.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79151925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-26DOI: 10.33609/2708-129x.87.10.2021.90-102
E. Trunova, Michailo Artamonov, T. Makotryk
Complexation in M (II) – Rut systems (M(II) = Co, Cu) was studied by electron absorption spectroscopy and pH-metric titration in water-ethanol solutions depending on the metal: ligand ratio (1: 1; 2: 1) and the pH of the medium. It was shown that the structure and stoichiometric composition of the complexation reaction products are influenced by such basic parameters as L:M and the pH value of the medium. Depending on the pH value, chelation involves certain binding sites, which primarily is associated with the redistribution of the electron density in the flavonoid molecule. In a weakly acidic or neutral medium, regardless of the M(II): Rut ratio, the formation of monoligand complexes of rutin with 3-d metals occurs with the participation of 5-OH and 4-C=O fragments of the A and C rings, and in an alkaline medium, chelation proceeds on the catecholic fragment of ring B rutin. Biligand complexes are formed with the participation of the gydroxo groups of the catechol fragment of each rutin molecule, and the formation of compounds with a ratio of 2:1 occurs both due to 5-OH and 4C=O and due to 3 ', 4'-OH groups. The calculated values of the stability constants of the complexes showed that the stability of the Co (II) complexes is several orders of magnitude lower than the stability of the corresponding Cu (II) complexes.
{"title":"SPECTROSCOPIC STUDIES OF Cu (II) AND Co (II) COMPLEXES WITH RUTIN IN SOLUTIONS","authors":"E. Trunova, Michailo Artamonov, T. Makotryk","doi":"10.33609/2708-129x.87.10.2021.90-102","DOIUrl":"https://doi.org/10.33609/2708-129x.87.10.2021.90-102","url":null,"abstract":"Complexation in M (II) – Rut systems (M(II) = Co, Cu) was studied by electron absorption spectroscopy and pH-metric titration in water-ethanol solutions depending on the metal: ligand ratio (1: 1; 2: 1) and the pH of the medium. It was shown that the structure and stoichiometric composition of the complexation reaction products are influenced by such basic parameters as L:M and the pH value of the medium. Depending on the pH value, chelation involves certain binding sites, which primarily is associated with the redistribution of the electron density in the flavonoid molecule. In a weakly acidic or neutral medium, regardless of the M(II): Rut ratio, the formation of monoligand complexes of rutin with 3-d metals occurs with the participation of 5-OH and 4-C=O fragments of the A and C rings, and in an alkaline medium, chelation proceeds on the catecholic fragment of ring B rutin. Biligand complexes are formed with the participation of the gydroxo groups of the catechol fragment of each rutin molecule, and the formation of compounds with a ratio of 2:1 occurs both due to 5-OH and 4C=O and due to 3 ', 4'-OH groups. The calculated values of the stability constants of the complexes showed that the stability of the Co (II) complexes is several orders of magnitude lower than the stability of the corresponding Cu (II) complexes.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86519222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-25DOI: 10.33609/2708-129x.87.09.2021.55-60
F. Scholz
The idea to study the electrochemistry of immobilized microparticles has been published by this author for the first time in 1989. In the last 32 years, this approach has been shown to be very successful not only for analytical characterization of solid materials, but also applicable to extract thermodynamic and kinetic data, and even to determine the age of metal specimen. In 2000, it has been shown that the electrochemistry of immobilized microdroplets gives an elegant access to determine the Gibbs free energies of ion transfer between immiscible solvents. These measurements are performed with a standard 3-electrode potentiostate and can be used also for solvents, which cannot be used in experiments with the classical 4-electrode technique. The electrochemistry of microparticles and microdroplets share several common features with respect to the electrode mechanisms: in both cases three-phase electrodes are realized and ion and electron transfer proceed simultaneously. This talk reviews the activities of the speaker and his cooperation partners during the last 3 decades paying special attention to those results, which are of general interest.
{"title":"ELECTROCHEMISTRY OF IMMOBILIZED MICROPARTICLES AND MICRODROPLETE: ACCESS TO FUNDAMENTAL DATA OF SOLID MATERIALS AND IONS","authors":"F. Scholz","doi":"10.33609/2708-129x.87.09.2021.55-60","DOIUrl":"https://doi.org/10.33609/2708-129x.87.09.2021.55-60","url":null,"abstract":"The idea to study the electrochemistry of immobilized microparticles has been published by this author for the first time in 1989. In the last 32 years, this approach has been shown to be very successful not only for analytical characterization of solid materials, but also applicable to extract thermodynamic and kinetic data, and even to determine the age of metal specimen. In 2000, it has been shown that the electrochemistry of immobilized microdroplets gives an elegant access to determine the Gibbs free energies of ion transfer between immiscible solvents. These measurements are performed with a standard 3-electrode potentiostate and can be used also for solvents, which cannot be used in experiments with the classical 4-electrode technique. \u0000The electrochemistry of microparticles and microdroplets share several common features with respect to the electrode mechanisms: in both cases three-phase electrodes are realized and ion and electron transfer proceed simultaneously. \u0000This talk reviews the activities of the speaker and his cooperation partners during the last 3 decades paying special attention to those results, which are of general interest.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79117941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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