Pub Date : 2023-09-29DOI: 10.33609/2708-129x.89.08.2023.78-96
Grace A V Magalhães-Ghiotto, L.C.A. Molina, K. Kudelko, L. Nichi, R. Bergamasco, Yuliya Dzyazko
Modifying membranes is a common approach to improve their separation ability. In this work, a series of the membranes, which reject colloidal particles of a wide diapason of their size, was obtained by modifying acetylcellulose microfiltration membranes with such rigid polymer as polymetylmetacrilate. Modifying was carried out by precipitation of the polymer in the membrane pores, the deposition occurred from the solutions of different concentrations. Other way was multistage modifying membranes with a solution of the same concentration. Depending on the modifying conditions, the content of polymetylmetacrilate in the membrane was 12–44 %. Morphology of the composite membranes was investigated by optical and scanning electron microscopy. Water test was also performed at 0.5–2 bar. The membranes obey Darcy law in this pressure diapason: thus, the pore radius can be approximately estimated from the Hagen – Poiseuille equation (18–63 nm). Moreover, the modifier minimizes the membrane compression: a decrease of the permeate flux is 19 % (pristine membrane) and 8% for membranes containing high amount of the modifier. Colloidal solutions of water-soluble linear polymer, vegetable protein and sol of hydrated iron oxide were also used for the membrane testing. The selectivity of composite membranes enhances in the row: polyvinylpyrollidone < iron oxide < albumin. In the case of vegetable protein, the membrane selectivity is 30–91% depending on the modifier content. The membrane with highest separation ability was used for clarification of goiaba juice: the selectivity towards total solids was found to reach 33–73%. The permeate can be used for the production of beverages, the concentrate is recommended for confectionery industry. Polymethylmetacrylate can be recommended for the membrane modifying as a binding component in the composite containing also hydrophilic agent.
{"title":"EFFECT OF POLYMER MODIFIER ON THE MORPHOLOGICAL AND SEPARATION PROPERTIES OF ASYMMETRIC MICROFILTRATION MEMBRANES","authors":"Grace A V Magalhães-Ghiotto, L.C.A. Molina, K. Kudelko, L. Nichi, R. Bergamasco, Yuliya Dzyazko","doi":"10.33609/2708-129x.89.08.2023.78-96","DOIUrl":"https://doi.org/10.33609/2708-129x.89.08.2023.78-96","url":null,"abstract":"Modifying membranes is a common approach to improve their separation ability. In this work, a series of the membranes, which reject colloidal particles of a wide diapason of their size, was obtained by modifying acetylcellulose microfiltration membranes with such rigid polymer as polymetylmetacrilate. Modifying was carried out by precipitation of the polymer in the membrane pores, the deposition occurred from the solutions of different concentrations. Other way was multistage modifying membranes with a solution of the same concentration. Depending on the modifying conditions, the content of polymetylmetacrilate in the membrane was 12–44 %. Morphology of the composite membranes was investigated by optical and scanning electron microscopy. Water test was also performed at 0.5–2 bar. The membranes obey Darcy law in this pressure diapason: thus, the pore radius can be approximately estimated from the Hagen – Poiseuille equation (18–63 nm). Moreover, the modifier minimizes the membrane compression: a decrease of the permeate flux is 19 % (pristine membrane) and 8% for membranes containing high amount of the modifier. Colloidal solutions of water-soluble linear polymer, vegetable protein and sol of hydrated iron oxide were also used for the membrane testing. The selectivity of composite membranes enhances in the row: polyvinylpyrollidone < iron oxide < albumin. In the case of vegetable protein, the membrane selectivity is 30–91% depending on the modifier content. The membrane with highest separation ability was used for clarification of goiaba juice: the selectivity towards total solids was found to reach 33–73%. The permeate can be used for the production of beverages, the concentrate is recommended for confectionery industry. Polymethylmetacrylate can be recommended for the membrane modifying as a binding component in the composite containing also hydrophilic agent.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139334551","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 : 2023-09-29DOI: 10.33609/2708-129x.89.08.2023.117-126
O. Zhukovetska
The creation of new reagents based on benzopyrylium derivatives with improved chemical-analytical characteristics is of interest because their preparative synthesis is relatively simple and consists in the condensation of triatomic phenols with β-dicarbonyl compounds. Benzopyryllium derivatives are reactive compounds and are able to redox reactions, complexes formation with polyvalent metal ions, and are also prone to acid-base transformations in solutions. It should be noted separately that hydroxyderivatives of benzopyrylium during complex formation can turn into anhydro bases with a quinoid structure, which leads to a significant bathochromic shift of the absorption band and an increase in the contrast of analytical reactions. The current work is devoted to the study of solvatochromic properties of a number of 6,7-dihydroxybenzopyrylium perchlorate derivatives: 6,7-dihydroxy-2,4-dimethylbenzopyrylium, 6,7-dihydroxy-2-phenyl-4-methylbenzopyrylium and 6,7-dihydroxy-2,4 -diphenylbenzopyrylium. The presented work is a continuation of research on synthesis, acid-base and complexation of 6,7-dihydroxybenzopyrylium derivatives. The influence of the nature of organic solvents was studied using the example of methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexanol, n-heptanol, n-nonanol, decanol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, butyl acetate, toluene, and chloroform. It is shown that when a polar solvent is replaced by a less polar one, a bathochromic shift of the maximum of the absorption band of 6,7-dihydroxybenzopyrylium derivatives is observed, which corresponds to the n→π* electronic transition. It was noted that there is a satisfactory correlation (R = 0.795–0.993) between the position of the maximum absorption of the dye and the values of the Hansen parameter, Kamlet – Taft, donor and acceptor number according to Gutman.
{"title":"SOLVATOCHROMIC PROPERTIES OF SOME 6,7-DIHYDROXYBENZOPYRYLLIUM PERCHLORATE DERIVATIVES","authors":"O. Zhukovetska","doi":"10.33609/2708-129x.89.08.2023.117-126","DOIUrl":"https://doi.org/10.33609/2708-129x.89.08.2023.117-126","url":null,"abstract":"The creation of new reagents based on benzopyrylium derivatives with improved chemical-analytical characteristics is of interest because their preparative synthesis is relatively simple and consists in the condensation of triatomic phenols with β-dicarbonyl compounds. Benzopyryllium derivatives are reactive compounds and are able to redox reactions, complexes formation with polyvalent metal ions, and are also prone to acid-base transformations in solutions. It should be noted separately that hydroxyderivatives of benzopyrylium during complex formation can turn into anhydro bases with a quinoid structure, which leads to a significant bathochromic shift of the absorption band and an increase in the contrast of analytical reactions. The current work is devoted to the study of solvatochromic properties of a number of 6,7-dihydroxybenzopyrylium perchlorate derivatives: 6,7-dihydroxy-2,4-dimethylbenzopyrylium, 6,7-dihydroxy-2-phenyl-4-methylbenzopyrylium and 6,7-dihydroxy-2,4 -diphenylbenzopyrylium. The presented work is a continuation of research on synthesis, acid-base and complexation of 6,7-dihydroxybenzopyrylium derivatives. The influence of the nature of organic solvents was studied using the example of methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexanol, n-heptanol, n-nonanol, decanol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, butyl acetate, toluene, and chloroform. It is shown that when a polar solvent is replaced by a less polar one, a bathochromic shift of the maximum of the absorption band of 6,7-dihydroxybenzopyrylium derivatives is observed, which corresponds to the n→π* electronic transition. It was noted that there is a satisfactory correlation (R = 0.795–0.993) between the position of the maximum absorption of the dye and the values of the Hansen parameter, Kamlet – Taft, donor and acceptor number according to Gutman.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139334089","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 : 2023-09-29DOI: 10.33609/2708-129x.89.08.2023.63-77
Volodymyr Ogenko
The review presents modern views and the history of the development of microscopic studies of nanosystems which heve been started 2014, after the Nobel Prize in Chemistry was awarded to Eric Betzig, William Mörner, and Stefan Gell "for the development of super-resolved fluorescence microscopy". Their work ushered in a new era of optical microscopy, enabling the precise examination of individual molecules and molecular clusters by using optical microscopes. By circumventing the diffraction limitations that had constrained traditional optical microscopes, scientists gained access to the nanoscale realm, investigating structures within the 1–100 nanometer range. Special attention is paid to the use of carbon quantum dots and plasmon resonance to enhance fluorescence when obtaining the effect of super-resolution images, which allow the use of optical microscopes in the estimation of the sizes of cluster and single molecules. This breakthrough in removing the diffraction limitation allowed scientists to use the working range of 1–100 nm and obtain 3D images of nanosystems and images of living cells. Particular attention is paid to the achievements and prospects of high-resolution fluorescent nanoscopy SRM, which is successfully developing and studying the nanoworld in the range of 1–100 nm at the level of scanning electron microscopy. In cell biology, nanomedicine, etc. are developing roadmaps for scientific breakthroughs in super-resolution visualization methods for "live" images. Prospects of Immuno-SERS microscopy and medicine of individual diagnosis are considered Key Findings: This article highlights the achievements and future prospects of super-resolution fluorescence microscopy SRM. High-resolution fluorescence microscopy has proven instrumental in advancing our understanding of the living world within the 1–100 nanometer range, which is akin to the capabilities of scanning electron microscopy. Within the domains of cell biology and nanomedicine, roadmaps for scientific breakthroughs are emerging, fueled by super-resolution imaging techniques, providing "live" insights into cellular processes. The horizons of Immuno-SERS Microscopy and Personalized Diagnostics Medicine are expanding, promising exciting prospects in the field of medical diagnostics.
{"title":"ACHIEVEMENTS IN PHYSICAL CHEMISTRY IN THE FIELD OF MICROSCOPY AND VISUALIZATION OF NANOSYSTEMS","authors":"Volodymyr Ogenko","doi":"10.33609/2708-129x.89.08.2023.63-77","DOIUrl":"https://doi.org/10.33609/2708-129x.89.08.2023.63-77","url":null,"abstract":"The review presents modern views and the history of the development of microscopic studies of nanosystems which heve been started 2014, after the Nobel Prize in Chemistry was awarded to Eric Betzig, William Mörner, and Stefan Gell \"for the development of super-resolved fluorescence microscopy\". Their work ushered in a new era of optical microscopy, enabling the precise examination of individual molecules and molecular clusters by using optical microscopes. By circumventing the diffraction limitations that had constrained traditional optical microscopes, scientists gained access to the nanoscale realm, investigating structures within the 1–100 nanometer range. Special attention is paid to the use of carbon quantum dots and plasmon resonance to enhance fluorescence when obtaining the effect of super-resolution images, which allow the use of optical microscopes in the estimation of the sizes of cluster and single molecules. This breakthrough in removing the diffraction limitation allowed scientists to use the working range of 1–100 nm and obtain 3D images of nanosystems and images of living cells. Particular attention is paid to the achievements and prospects of high-resolution fluorescent nanoscopy SRM, which is successfully developing and studying the nanoworld in the range of 1–100 nm at the level of scanning electron microscopy. In cell biology, nanomedicine, etc. are developing roadmaps for scientific breakthroughs in super-resolution visualization methods for \"live\" images. Prospects of Immuno-SERS microscopy and medicine of individual diagnosis are considered Key Findings: This article highlights the achievements and future prospects of super-resolution fluorescence microscopy SRM. High-resolution fluorescence microscopy has proven instrumental in advancing our understanding of the living world within the 1–100 nanometer range, which is akin to the capabilities of scanning electron microscopy. Within the domains of cell biology and nanomedicine, roadmaps for scientific breakthroughs are emerging, fueled by super-resolution imaging techniques, providing \"live\" insights into cellular processes. The horizons of Immuno-SERS Microscopy and Personalized Diagnostics Medicine are expanding, promising exciting prospects in the field of medical diagnostics.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139334428","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 : 2023-09-29DOI: 10.33609/2708-129x.89.08.2023.109-116
M. Onisko
Condensed heterocycles based on 1,2,4-triazole have a wide range of biological activity. The introduction of a pharmacophore fragment of an aryl tertiary residue into their composition can significantly increase the bioactivity of the obtained compounds. Therefore, the synthesis of condensed derivatives of symmetrical 1,2,4-triazole with aryltellurium fragment is an urgent task. One of the most convenient and effective methods for introducing an aryltellurium fragment into such systems is the method of electrophilic intramolecular cyclisation of alkenyl derivatives of azaheterocycles. The aim of this work was to determine the effect of the nature of the substituent at position five of the initial N-allyl derivatives of 1,2,4-triazol-3-thione on the regioselectivity of electrophilic heterocyclization with p-methoxyphenyltellurium trichloride. The reaction of tellurium-induced heterocyclisation of N-allyl-substituted 1,2,4-triazole-3-thione with was carried out in acetic acid medium at room temperature under stirring for 12 hours. It was found that the reactions of 5-aryl(heteryl)substituted N-allyl derivatives of 1,2,4-triazole-3-thione with p-methoxyphenyltellurium trichloride lead to the formation of chlorides 6-((dichloro(4-methoxyphenyl)-λ4-tellanyl)methyl)-5,6-dihydrothiazolo[2,3-c][1,2,4]triazol-1-ium chlorides with an exocyclic p-methoxyphenyltellurium fragment. The yield of the obtained thiazolotriazolium salts was 68-87%. It should be noted that the use of a double amount of electrophilic reagent did not lead to the formation of a thiazolotriazole complex with p-methoxyphenyltellurium trichloride, which was observed during the heterocyclisation of S-alkenyl derivatives of 1,2,4-triazole. Thus, the tellurium-induced cyclization of 5-substituted N-allyl derivatives of 1,2, 4-triazol-3-thione derivatives by p-methoxyphenyltellurium trichloride is regioselective with the formation of 6-((dichloro(4-methoxyphenyl)-λ4-tellanyl)methyl)-5,6-dihydrothiazolo[2,3-c][1,2,4]triazol-1-ium chlorides and annulation of the thiazoline cycle. The introduction of aryl and heteryl substituents of different nature does not affect the regioselectivity of the heteroannulation process.
{"title":"ARYLTELLUROCHLORINATION OF 5-ARYL(HETERYL)SUBSTITUTED N-ALLYL-1,2,4-TRIAZOLE-3-THIONE DERIVATIVES","authors":"M. Onisko","doi":"10.33609/2708-129x.89.08.2023.109-116","DOIUrl":"https://doi.org/10.33609/2708-129x.89.08.2023.109-116","url":null,"abstract":"Condensed heterocycles based on 1,2,4-triazole have a wide range of biological activity. The introduction of a pharmacophore fragment of an aryl tertiary residue into their composition can significantly increase the bioactivity of the obtained compounds. Therefore, the synthesis of condensed derivatives of symmetrical 1,2,4-triazole with aryltellurium fragment is an urgent task. One of the most convenient and effective methods for introducing an aryltellurium fragment into such systems is the method of electrophilic intramolecular cyclisation of alkenyl derivatives of azaheterocycles. The aim of this work was to determine the effect of the nature of the substituent at position five of the initial N-allyl derivatives of 1,2,4-triazol-3-thione on the regioselectivity of electrophilic heterocyclization with p-methoxyphenyltellurium trichloride. The reaction of tellurium-induced heterocyclisation of N-allyl-substituted 1,2,4-triazole-3-thione with was carried out in acetic acid medium at room temperature under stirring for 12 hours. It was found that the reactions of 5-aryl(heteryl)substituted N-allyl derivatives of 1,2,4-triazole-3-thione with p-methoxyphenyltellurium trichloride lead to the formation of chlorides 6-((dichloro(4-methoxyphenyl)-λ4-tellanyl)methyl)-5,6-dihydrothiazolo[2,3-c][1,2,4]triazol-1-ium chlorides with an exocyclic p-methoxyphenyltellurium fragment. The yield of the obtained thiazolotriazolium salts was 68-87%. It should be noted that the use of a double amount of electrophilic reagent did not lead to the formation of a thiazolotriazole complex with p-methoxyphenyltellurium trichloride, which was observed during the heterocyclisation of S-alkenyl derivatives of 1,2,4-triazole. Thus, the tellurium-induced cyclization of 5-substituted N-allyl derivatives of 1,2, 4-triazol-3-thione derivatives by p-methoxyphenyltellurium trichloride is regioselective with the formation of 6-((dichloro(4-methoxyphenyl)-λ4-tellanyl)methyl)-5,6-dihydrothiazolo[2,3-c][1,2,4]triazol-1-ium chlorides and annulation of the thiazoline cycle. The introduction of aryl and heteryl substituents of different nature does not affect the regioselectivity of the heteroannulation process.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139334635","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 : 2023-09-29DOI: 10.33609/2708-129x.89.08.2023.97-108
O. Trunova, Оeksandra Berezhnytska, O. Rohovtsov
In this work, the FeEDDSNP nanocomplex was synthesized by dissolution peptization of a freshly precipitated sol of iron hydroxide Fe(OH)3 in an aqueous solution of the racemic form of Н4EDDS. The complex was characterized by electron absorption spectroscopy and IR spectroscopy. It was shown that the structure of the nanocomplex is identical to the structure of the FeEDDS complex obtained using a two-stage technology. The position of the absorption maxima of iron nanoparticles practically does not change depending on the storage time at room temperature, which indicates the stability of the synthesized nanocomplex. The nanodispersed FeEDDSNP complex is more soluble in water (275 g/l) compared to the FeEDDS complex obtained by the classical method (150 g/l), which greatly facilitates its use as a biologically active compound. To determine the stability of the system depending on the pH, the electrokinetic potential was measured to select the optimal pH of the medium and concentrations to obtain stable dispersed systems. It is shown that at low pH (1.5–4.0) there is a drop in the electrokinetic potential, and when the pH increases, the
{"title":"SYNTHESIS AND STUDY OF NANO-SIZED COMPLEX OF Fe(III) WITH ETHYLENEDIAMINEDISUCCINIC ACID","authors":"O. Trunova, Оeksandra Berezhnytska, O. Rohovtsov","doi":"10.33609/2708-129x.89.08.2023.97-108","DOIUrl":"https://doi.org/10.33609/2708-129x.89.08.2023.97-108","url":null,"abstract":"In this work, the FeEDDSNP nanocomplex was synthesized by dissolution peptization of a freshly precipitated sol of iron hydroxide Fe(OH)3 in an aqueous solution of the racemic form of Н4EDDS. The complex was characterized by electron absorption spectroscopy and IR spectroscopy. It was shown that the structure of the nanocomplex is identical to the structure of the FeEDDS complex obtained using a two-stage technology. The position of the absorption maxima of iron nanoparticles practically does not change depending on the storage time at room temperature, which indicates the stability of the synthesized nanocomplex. The nanodispersed FeEDDSNP complex is more soluble in water (275 g/l) compared to the FeEDDS complex obtained by the classical method (150 g/l), which greatly facilitates its use as a biologically active compound. To determine the stability of the system depending on the pH, the electrokinetic potential was measured to select the optimal pH of the medium and concentrations to obtain stable dispersed systems. It is shown that at low pH (1.5–4.0) there is a drop in the electrokinetic potential, and when the pH increases, the","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139334429","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 : 2023-07-28DOI: 10.33609/2708-129x.89.06.2023.55-70
O. Trunova, N. Rusakova
An analysis of the fluorescent characteristics of ethylenediamine-N,N'-disuccinic and N,N-bis(phosphonomethyl)-2-aminopropionic acids was carried out depending on the pH of the solutions. It was established that the change in fluorescence intensity and lifetime is associated with the formation of variously protonated forms of acids in which stable H-cycles are formed with the participation of hydrogen bonds. The energies of the singlet and triplet levels of the ligands were experimentally determined, the values of which are higher than the energy of the radiative level of the Nd(III) ion, which indicates the possibility of intramolecular transfer of the excitation energy to the resonance level of the lanthanide ion. It was established that both homo- and heteronuclear complexes of Nd(III) exhibit 4f-luminescence in the near-IR region. It was found that for phosphorus-containing complexes there is an increase in luminescence intensity and relative quantum yields in comparison with aminocarboxylate analogs. In heterometallic complexes based on aminopolycarboxylic acids, the intramolecular transfer of energy from the excited level of Co(II) to the resonance level of the f-metal leads to sensitization of the 4f-luminescence of the neodymium ion.
{"title":"LUMINESCENT PROPERTIES OF Nd(III) COMPLEXES WITH ETHYLENEDIAMINE-N,N'-DISUCCINIC AND N,N-BIS(PHOSPHONOMETHYL)-2-AMINOPROPIONIC ACIDS","authors":"O. Trunova, N. Rusakova","doi":"10.33609/2708-129x.89.06.2023.55-70","DOIUrl":"https://doi.org/10.33609/2708-129x.89.06.2023.55-70","url":null,"abstract":"An analysis of the fluorescent characteristics of ethylenediamine-N,N'-disuccinic and N,N-bis(phosphonomethyl)-2-aminopropionic acids was carried out depending on the pH of the solutions. It was established that the change in fluorescence intensity and lifetime is associated with the formation of variously protonated forms of acids in which stable H-cycles are formed with the participation of hydrogen bonds. The energies of the singlet and triplet levels of the ligands were experimentally determined, the values of which are higher than the energy of the radiative level of the Nd(III) ion, which indicates the possibility of intramolecular transfer of the excitation energy to the resonance level of the lanthanide ion. It was established that both homo- and heteronuclear complexes of Nd(III) exhibit 4f-luminescence in the near-IR region. It was found that for phosphorus-containing complexes there is an increase in luminescence intensity and relative quantum yields in comparison with aminocarboxylate analogs. In heterometallic complexes based on aminopolycarboxylic acids, the intramolecular transfer of energy from the excited level of Co(II) to the resonance level of the f-metal leads to sensitization of the 4f-luminescence of the neodymium ion.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86268926","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 : 2023-07-28DOI: 10.33609/2708-129x.89.06.2023.79-96
S. Kuleshov, I. Novoselova, Olha Medvezhynska
The hydrogen evolution reaction (HER) is one of the most promising methods of obtaining high-purity hydrogen. However, the high cost and limited resources of materials with low cathodic hydrogen evolution overvoltage values, such as platinum group metals, are the main obstacles to the use HER for obtaining hydrogen on an industrial scale. Therefore, it is necessary to develop new alternative materials and methods of their production. One of the promising materials are catalysts based on refractory metals, in particular tungsten carbides. Metal tungsten can also be used for these purposes. In our opinion, high-temperature electrochemical synthesis (HTES) in molten salts can be a promising method of obtaining materials with properties that meet the requirements for effective catalysts, namely: ultra-dispersity, high specific surface area, mesoporosity and defective structure, high chemical and electrochemical stability. Therefore, the purpose of this work is to evaluate the electrocatalytic activity of a group of materials for HER, which are obtained by HTES in melts. Four samples of electrolytic materials were chosen for the study: tungsten, carbon, tungsten mono- and semi-carbides (WC and W2С). All samples were characterized in detail using X-ray diffraction (phase composition), SEM (morphology), Raman spectroscopy (structure of carbon phases), DTG (free carbon content). Based on the analysis of the obtained data, it was established that all samples can be used as catalysts: crystallites have a nanometer size and a large number of structural defects; morphology provides increased surface area; tungsten carbide particles are covered with a layer of free carbon, which prevents oxidation of carbide to WO3, which has a lower catalytic activity; carbon particles are nanosized (20–30 nm) and contain a large number of structural defects; tungsten carbide-based samples contain free carbon, which increases the specific surface area, but does not cause clogging of pores. Polarization measurements were carried out at room temperature at a polarization rate of 5 mV/s in a standard three-electrode cell with an Ag|AgCl reference electrode. 1N H2SO4 was used as a base solution, which was bubbled with high-purity argon. Onset potentials for all samples are -0.05 – -0.25 V (in order WC/C – W2C/WC/C – C – W). The overvoltage and Tafel slope were calculated and WC/C composite was shown to have the lowest values of -0.2 V and -75 mV, respectively. Electrolytic composite of tungsten carbide/carbon have demonstrated the best characteristics, so we plan to continue the development of synthesis method of carbide compounds, which will allow us to reveal even greater potential of carbide catalysts and pave the way for their wide application in catalytic processes.
{"title":"ELECTROLYTIC CATALYSTS BASED ON TUNGSTEN AND CARBON COMPOUNDS FOR THE HYDROGEN EVOLUTION REACTION","authors":"S. Kuleshov, I. Novoselova, Olha Medvezhynska","doi":"10.33609/2708-129x.89.06.2023.79-96","DOIUrl":"https://doi.org/10.33609/2708-129x.89.06.2023.79-96","url":null,"abstract":"The hydrogen evolution reaction (HER) is one of the most promising methods of obtaining high-purity hydrogen. However, the high cost and limited resources of materials with low cathodic hydrogen evolution overvoltage values, such as platinum group metals, are the main obstacles to the use HER for obtaining hydrogen on an industrial scale. Therefore, it is necessary to develop new alternative materials and methods of their production. One of the promising materials are catalysts based on refractory metals, in particular tungsten carbides. Metal tungsten can also be used for these purposes. In our opinion, high-temperature electrochemical synthesis (HTES) in molten salts can be a promising method of obtaining materials with properties that meet the requirements for effective catalysts, namely: ultra-dispersity, high specific surface area, mesoporosity and defective structure, high chemical and electrochemical stability. Therefore, the purpose of this work is to evaluate the electrocatalytic activity of a group of materials for HER, which are obtained by HTES in melts. Four samples of electrolytic materials were chosen for the study: tungsten, carbon, tungsten mono- and semi-carbides (WC and W2С). All samples were characterized in detail using X-ray diffraction (phase composition), SEM (morphology), Raman spectroscopy (structure of carbon phases), DTG (free carbon content). \u0000Based on the analysis of the obtained data, it was established that all samples can be used as catalysts: crystallites have a nanometer size and a large number of structural defects; morphology provides increased surface area; tungsten carbide particles are covered with a layer of free carbon, which prevents oxidation of carbide to WO3, which has a lower catalytic activity; carbon particles are nanosized (20–30 nm) and contain a large number of structural defects; tungsten carbide-based samples contain free carbon, which increases the specific surface area, but does not cause clogging of pores. \u0000Polarization measurements were carried out at room temperature at a polarization rate of 5 mV/s in a standard three-electrode cell with an Ag|AgCl reference electrode. 1N H2SO4 was used as a base solution, which was bubbled with high-purity argon. Onset potentials for all samples are -0.05 – -0.25 V (in order WC/C – W2C/WC/C – C – W). The overvoltage and Tafel slope were calculated and WC/C composite was shown to have the lowest values of -0.2 V and -75 mV, respectively. \u0000Electrolytic composite of tungsten carbide/carbon have demonstrated the best characteristics, so we plan to continue the development of synthesis method of carbide compounds, which will allow us to reveal even greater potential of carbide catalysts and pave the way for their wide application in catalytic processes.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76099046","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 : 2023-07-28DOI: 10.33609/2708-129x.89.06.2023.97-110
O. Farat, S. Varenichenko, V. Markov, K. Yanova
The aim of the work was to establish the spectrum of biological activity of new derivatives of 9-bromo-1,2,3,4-tetrahydroacridine due to the limited amount of literature data. In silico prediction of selected bromo-derivatives of hydrogenated acridines was performed using the SuperPred 3.0 web resource. The obtained results were compared with the results of prediction of active drugs that contain the acridine cycle in their structure - Tacrine, Amiridine and Amsacrine. Results ≤80% were taken into account. The most promising compound was 9-bromo-1,2,3,4-tetrahydroacridine. A common predicted target for bromide-hydrogenated acridines and all three drugs is DNA-(apurine or apyrimidine site) lyase with binding probabilities ranging from 82-97.5%. Common predicted targets for 9-bromo-1,2,3,4-tetrahydroacridine derivatives, Tacrine and Amsacrine are butyrylcholinesterase (90.4-98.2%) and transcription factor 1-α (92.02-98.01 %). Cathepsin D, toll-like receptor 8 and glucose transporter are promising common targets for further research, but it should be noted that the probability of binding in these drugs was below 80%. All selected compounds were tested for Lipinski's criteria. In addition, in silico prediction of the acute toxicity of bromo-derivatives of acridine was performed in rats with four types of administration. The safest compound according to the oral method of administration is the compound 9-bromo-2-tert-butyl-1,2,3,4-tetrahydroacridine (1570 mg/kg), while the compound 9-bromo-1,2 turned out to be more toxic than the others ,3,4-tetrahydroacridine (565.3 mg/kg). The estimated average lethal dose of Tacrine after a single oral dose to rats is 40 mg/kg. The prediction results confirmed the prospects of further research among the class of hydrogenated bromoderivatives of acridines.
{"title":"IN SILICO PREDICTION OF BIOLOGICAL ACTIVITY OF BROMO DERIVATIVES OF HYDROACRIDINES","authors":"O. Farat, S. Varenichenko, V. Markov, K. Yanova","doi":"10.33609/2708-129x.89.06.2023.97-110","DOIUrl":"https://doi.org/10.33609/2708-129x.89.06.2023.97-110","url":null,"abstract":"The aim of the work was to establish the spectrum of biological activity of new derivatives of 9-bromo-1,2,3,4-tetrahydroacridine due to the limited amount of literature data. In silico prediction of selected bromo-derivatives of hydrogenated acridines was performed using the SuperPred 3.0 web resource. The obtained results were compared with the results of prediction of active drugs that contain the acridine cycle in their structure - Tacrine, Amiridine and Amsacrine. Results ≤80% were taken into account. The most promising compound was 9-bromo-1,2,3,4-tetrahydroacridine. A common predicted target for bromide-hydrogenated acridines and all three drugs is DNA-(apurine or apyrimidine site) lyase with binding probabilities ranging from 82-97.5%. Common predicted targets for 9-bromo-1,2,3,4-tetrahydroacridine derivatives, Tacrine and Amsacrine are butyrylcholinesterase (90.4-98.2%) and transcription factor 1-α (92.02-98.01 %). Cathepsin D, toll-like receptor 8 and glucose transporter are promising common targets for further research, but it should be noted that the probability of binding in these drugs was below 80%. All selected compounds were tested for Lipinski's criteria. In addition, in silico prediction of the acute toxicity of bromo-derivatives of acridine was performed in rats with four types of administration. The safest compound according to the oral method of administration is the compound 9-bromo-2-tert-butyl-1,2,3,4-tetrahydroacridine (1570 mg/kg), while the compound 9-bromo-1,2 turned out to be more toxic than the others ,3,4-tetrahydroacridine (565.3 mg/kg). The estimated average lethal dose of Tacrine after a single oral dose to rats is 40 mg/kg. The prediction results confirmed the prospects of further research among the class of hydrogenated bromoderivatives of acridines.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78488753","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 : 2023-07-28DOI: 10.33609/2708-129x.89.06.2023.71-78
T. Plutenko, O. V’yunov, O. Fedorchuk, O. Yanchevskii, P. Torchyniuk
La0.67LixTi1-xAlxO3 ceramics (x = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30) were synthesized with the use of Al2O3 and an aqueous solution of Al(NO3)3 as an aluminium source. In both cases, the ceramics preserve a high dielectric constant ε ~ 105. It was found that the single-phase La0.67LixTi1-xAlxO3 perovskite structure is formed at temperatures above 1200 C. It was shown that the use of Al(NO3)3 allows simplifying the synthesis: reduction in the sintering temperature by 20 C, Li loss and, as a result, an increase in the density of ceramics. Ceramics La0.67Li0.15Ti0.85Al0.15O3 with a maximum density higher than 85 % were sintered at about 1280 and 1300 C of with the use of Al(NO3)3 and Al2O3 respectively. Frequency spectra of imaginary parts of impedance and electrical modulus demonstrate two dispersion regions that refer to processes in the ceramic grains’ boundaries and ceramic grains. Ceramic samples synthesized using Al(NO3)3 solutions tend to exhibit higher dielectric constants than those synthesized using Al2O3. At a frequency of 100 Hz, the dielectric constant for ceramics synthesized using Al(NO3)3 aqueous solution is 70600, whereas that for ceramics synthesized using Al2O3 is 44300. Obtained materials are useful for microelectronics, energy storage and harvesting devices.
{"title":"Al-DOPED LANTHANUM-LITHIUM TITANATE WITH HIGH DIELECTRIC CONSTANT","authors":"T. Plutenko, O. V’yunov, O. Fedorchuk, O. Yanchevskii, P. Torchyniuk","doi":"10.33609/2708-129x.89.06.2023.71-78","DOIUrl":"https://doi.org/10.33609/2708-129x.89.06.2023.71-78","url":null,"abstract":"La0.67LixTi1-xAlxO3 ceramics (x = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30) were synthesized with the use of Al2O3 and an aqueous solution of Al(NO3)3 as an aluminium source. In both cases, the ceramics preserve a high dielectric constant ε ~ 105. It was found that the single-phase La0.67LixTi1-xAlxO3 perovskite structure is formed at temperatures above 1200 C. It was shown that the use of Al(NO3)3 allows simplifying the synthesis: reduction in the sintering temperature by 20 C, Li loss and, as a result, an increase in the density of ceramics. Ceramics La0.67Li0.15Ti0.85Al0.15O3 with a maximum density higher than 85 % were sintered at about 1280 and 1300 C of with the use of Al(NO3)3 and Al2O3 respectively. Frequency spectra of imaginary parts of impedance and electrical modulus demonstrate two dispersion regions that refer to processes in the ceramic grains’ boundaries and ceramic grains. Ceramic samples synthesized using Al(NO3)3 solutions tend to exhibit higher dielectric constants than those synthesized using Al2O3. At a frequency of 100 Hz, the dielectric constant for ceramics synthesized using Al(NO3)3 aqueous solution is 70600, whereas that for ceramics synthesized using Al2O3 is 44300. Obtained materials are useful for microelectronics, energy storage and harvesting devices.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90062730","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 : 2023-06-26DOI: 10.33609/2708-129x.89.05.2023.26-36
S. Shulga, O. Shulga
There are synthesized various types of polymethine dyes from trifluoromethylthiazolo(3,2-a)pyrimidinium and trifluoromethylpyrimido(2,1-b)benzthiazolium perchlorates various types of polymethine dyes were obtained – styryls, monomethinecyanines, symmetrical and asymmetrical carbocyanines, merocyanines. The absorption maxima and their intensities are determined for each dye, absorption characteristics curves and elemental analysis data for Carbon, Hydrogen and Sulfur are provided. As a result of the dyes absorption maxima analysis containing a tri-fluoromethyl group in the pyrimidine ring and synthesized in this reaserch with the absorption maxima of dyes without a trifluoromethyl group in the pyrimidine ring, the bathochromic effect of the trifluoromethyl group on the dyes absorption maxima was established. The phenyl in the fifth position of the thiazole ring causes a bathochromic shift of the dye absorption maximum. There are characteristics of the absorption curve. The α- and γ-derivatives of monocyanines have a significant difference. The curve is flat with one absorption maximum for α-derivatives.The curve is narrower and contains two absorption maxima for γ-derivatives. The absorption curves of merocyanines also contain two maxima. The results of elemental analysis for Carbon, Hydrogen and Sulfur are presented. The resulting polymethine dyes are easily synthesized from thiazolo(3,2-a)pyrimidinium and pyramido(2,3-b)benzthiazole in an acetic anhydride medium with product output at least 41%. The styrene product output are 53–93%. Synthesized dyes are crystallized from acetic anhydride. Symmetrical carbocyanines are crystallized from dimethylformamide.
{"title":"POLYMETHYNE DYES WITH THIAZOLO (3,2-a)PYRIMIDINE AND PYRIMIDO(2,1-b)BENZTHIAZOLE SALTS WITH A TRIFLUOROMETHYL GROUP IN THE PYRIMIDINE CYCLE.","authors":"S. Shulga, O. Shulga","doi":"10.33609/2708-129x.89.05.2023.26-36","DOIUrl":"https://doi.org/10.33609/2708-129x.89.05.2023.26-36","url":null,"abstract":"There are synthesized various types of polymethine dyes from trifluoromethylthiazolo(3,2-a)pyrimidinium and trifluoromethylpyrimido(2,1-b)benzthiazolium perchlorates various types of polymethine dyes were obtained – styryls, monomethinecyanines, symmetrical and asymmetrical carbocyanines, merocyanines. The absorption maxima and their intensities are determined for each dye, absorption characteristics curves and elemental analysis data for Carbon, Hydrogen and Sulfur are provided. As a result of the dyes absorption maxima analysis containing a tri-fluoromethyl group in the pyrimidine ring and synthesized in this reaserch with the absorption maxima of dyes without a trifluoromethyl group in the pyrimidine ring, the bathochromic effect of the trifluoromethyl group on the dyes absorption maxima was established. The phenyl in the fifth position of the thiazole ring causes a bathochromic shift of the dye absorption maximum. There are characteristics of the absorption curve. The α- and γ-derivatives of monocyanines have a significant difference. The curve is flat with one absorption maximum for α-derivatives.The curve is narrower and contains two absorption maxima for γ-derivatives. The absorption curves of merocyanines also contain two maxima. The results of elemental analysis for Carbon, Hydrogen and Sulfur are presented. The resulting polymethine dyes are easily synthesized from thiazolo(3,2-a)pyrimidinium and pyramido(2,3-b)benzthiazole in an acetic anhydride medium with product output at least 41%. The styrene product output are 53–93%. Synthesized dyes are crystallized from acetic anhydride. Symmetrical carbocyanines are crystallized from dimethylformamide.","PeriodicalId":23394,"journal":{"name":"Ukrainian Chemistry Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84762575","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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