Pub Date : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264893
R. Khoma
In memory of the member of NAS of Ukraine Serhii Andriiovych Andronati
为了纪念乌克兰国家科学院的成员，谢尔盖·安德里奥维奇·安德罗纳蒂
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Pub Date : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264888
I. I. Zheltvay, E. V. Timukhin, R. Khoma, S. Vodzinskii
Recently, the practice of analytical chemistry has included the method of chemical chromaticity, based on the measurement of the integral characteristics of the color reflected from the surface of the analyte and which makes it possible to distinguish between spectrally close substances. With the spread scanners and computer programs for color image processing, a fast and objective method for assessing the color characteristics of colored samples has appeared, opening up the prospect of using chemical chromaticity in the chemical analysis of various objects in the absence of special spectrophotometric equipment or with minimal use of it. Thus, the process of chemical chromaticity analysis is divided into two parts: obtaining a high-quality digital image of the analyzed object and processing the resulting file in a graphics editor. The article describes in detail the methodological issues of scanning solutions, powders, surfaces of dosage forms using an office scanner and processing the resulting digital images in a graphics editor. On the example of model samples, standard solutions of salts FeCl3⋅6H2O, CoCl2⋅6H2O, CuSO4⋅5H2O, it is shown that in the range of 6–60 g/l their concentrations can be determined with sufficient accuracy as with using its absorption spectra (registered on a Lambda 9 PerkinElmer spectrophotometer) or spectra of diffuse reflection (on the same instrument using a scanning sphere B013–9941), and when using an desktop scanner HP scanjet 2200c with HP PrecisionScan LTX 1.2 software, followed by digital processing of the scan in Photoshop CS3. Acquisition and analysis of digital images of analytes can be considered as an inexpensive replacement for spectrophotometry in a certain interval of concentrations, comparable with it in terms of accuracy and reliability of determinations. The introduction of this technique into the educational process makes it possible to increase the efficiency of teaching students when mastering the skills of converting color characteristics into optical density values and to better understand the principles of the science of color and light absorption. The method can be made mobile for analysis of results in remote areas using a portable scanner powered by battery.
{"title":"OFFICE SCANNER USE FOR OBTAINING ANALYSIS OBJECTS DIGITAL IMAGES AND THEIR COLOR CHARACTERISTICS COMPUTER DETERMINATION","authors":"I. I. Zheltvay, E. V. Timukhin, R. Khoma, S. Vodzinskii","doi":"10.18524/2304-0947.2022.2(82).264888","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.2(82).264888","url":null,"abstract":"Recently, the practice of analytical chemistry has included the method of chemical chromaticity, based on the measurement of the integral characteristics of the color reflected from the surface of the analyte and which makes it possible to distinguish between spectrally close substances. With the spread scanners and computer programs for color image processing, a fast and objective method for assessing the color characteristics of colored samples has appeared, opening up the prospect of using chemical chromaticity in the chemical analysis of various objects in the absence of special spectrophotometric equipment or with minimal use of it. Thus, the process of chemical chromaticity analysis is divided into two parts: obtaining a high-quality digital image of the analyzed object and processing the resulting file in a graphics editor. The article describes in detail the methodological issues of scanning solutions, powders, surfaces of dosage forms using an office scanner and processing the resulting digital images in a graphics editor. On the example of model samples, standard solutions of salts FeCl3⋅6H2O, CoCl2⋅6H2O, CuSO4⋅5H2O, it is shown that in the range of 6–60 g/l their concentrations can be determined with sufficient accuracy as with using its absorption spectra (registered on a Lambda 9 PerkinElmer spectrophotometer) or spectra of diffuse reflection (on the same instrument using a scanning sphere B013–9941), and when using an desktop scanner HP scanjet 2200c with HP PrecisionScan LTX 1.2 software, followed by digital processing of the scan in Photoshop CS3. Acquisition and analysis of digital images of analytes can be considered as an inexpensive replacement for spectrophotometry in a certain interval of concentrations, comparable with it in terms of accuracy and reliability of determinations. The introduction of this technique into the educational process makes it possible to increase the efficiency of teaching students when mastering the skills of converting color characteristics into optical density values and to better understand the principles of the science of color and light absorption. The method can be made mobile for analysis of results in remote areas using a portable scanner powered by battery.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80822159","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 : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264892
P. E. Khoma, N. Abramova, S. Kiro, I. M. Knish
The article deals with the issues of protection of the respiratory organs from the toxic effects of ammonia, based on the research of employees of the Physical-chemical institute for environment and human protection of MES OF Ukraine and NAS of Ukraine. The physicochemical properties of ammonia and its toxicological characteristics are discussed in detail. Emergency hygienic regulations and reference levels of its concentration in the air are given, depending on the severity of possible effects. Activated carbon, the most widely used for equipping gas-absorbing cartridges of respirators and industrial gas masks, does not have the ability to selectively absorb ammonia without treatment with chemically active compounds. To enhance selectivity, activated carbon is infiltrated with d-metal salts and organic polybasic acids. An alternative to granular charcoal sorbents are ion-exchange fibrous materials or impregnated fibrous chemisorbents (IFCS), which have a significantly lower weight and breathing resistance. Impregnation was carried out with solutions of citric acid, and glycerol, sodium chloride, and ethanol were used as modifiers to achieve a uniform distribution of citric acid on the surface of the fibers and increase adhesion to them. The study of the sorption characteristics of IFCS as part of the gas-absorbing cartridge of the «Klen-K1» respirator was carried out with dry and moistened samples under dynamic conditions close to the actual operation of respiratory protection equipment: NH3 concentration in the gas-air mixture 700 mg/m3 (35 TVL), relative humidity φ = 0 ÷ 72%, linear flow rate – 5,1 sm/s. It is shown that the humidity of the gas-air mixture plays a decisive role in the efficiency of ammonia sorption, it activates the protective properties of IFCS. It has been established that gas-absorbing cartridges equipped with the developed samples of IFCS impregnated with a 40.0% solution of citric acid with the addition of 3.3% glycerol and 1.0% sodium chloride provide the normalized requirements for class K1 gas filters (ammonia) with humidity of the inhaled air ≥ 30%. The presence of «free» water provides a more complete «activation» of the specified chemisorbent for this toxicant.
{"title":"RESPIRATORY ORGANS PROTECTION FROM THE AMMONIA ACTION","authors":"P. E. Khoma, N. Abramova, S. Kiro, I. M. Knish","doi":"10.18524/2304-0947.2022.2(82).264892","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.2(82).264892","url":null,"abstract":"The article deals with the issues of protection of the respiratory organs from the toxic effects of ammonia, based on the research of employees of the Physical-chemical institute for environment and human protection of MES OF Ukraine and NAS of Ukraine. The physicochemical properties of ammonia and its toxicological characteristics are discussed in detail. Emergency hygienic regulations and reference levels of its concentration in the air are given, depending on the severity of possible effects. Activated carbon, the most widely used for equipping gas-absorbing cartridges of respirators and industrial gas masks, does not have the ability to selectively absorb ammonia without treatment with chemically active compounds. To enhance selectivity, activated carbon is infiltrated with d-metal salts and organic polybasic acids. An alternative to granular charcoal sorbents are ion-exchange fibrous materials or impregnated fibrous chemisorbents (IFCS), which have a significantly lower weight and breathing resistance. Impregnation was carried out with solutions of citric acid, and glycerol, sodium chloride, and ethanol were used as modifiers to achieve a uniform distribution of citric acid on the surface of the fibers and increase adhesion to them. The study of the sorption characteristics of IFCS as part of the gas-absorbing cartridge of the «Klen-K1» respirator was carried out with dry and moistened samples under dynamic conditions close to the actual operation of respiratory protection equipment: NH3 concentration in the gas-air mixture 700 mg/m3 (35 TVL), relative humidity φ = 0 ÷ 72%, linear flow rate – 5,1 sm/s. It is shown that the humidity of the gas-air mixture plays a decisive role in the efficiency of ammonia sorption, it activates the protective properties of IFCS. It has been established that gas-absorbing cartridges equipped with the developed samples of IFCS impregnated with a 40.0% solution of citric acid with the addition of 3.3% glycerol and 1.0% sodium chloride provide the normalized requirements for class K1 gas filters (ammonia) with humidity of the inhaled air ≥ 30%. The presence of «free» water provides a more complete «activation» of the specified chemisorbent for this toxicant.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79217894","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 : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264890
A. Y. Kornylov, A. A. Krysko, O. Krysko, S. E. Sambursky
The aim of this work is to develop a simple, fast and efficient method for the synthesis of optically pure enantiomers of some 5-aryl-substituted 3-methyl‑7-nitro‑1,2-dihydro‑3H‑1,4-benzodiazepin‑2-ones using simple reagents. In the course of the study, we found that the interaction of 2-amino‑5-nitrobenzophenone or 2-amino‑2’-chloro‑5-nitrobenzophenone with optically active L- or D‑α-alanine N‑carboxyanhydrides in the presence of two equivalents of trifluoroacetic acid does not leads to the formation of the corresponding reaction intermediates (2-amino-N-(2-benzoylphenyl)propanamide), even when refluxed for 24 hours in xylene. Acylation of 5-nitro‑2-aminobenzophenones with hydrochlorides of L- or D‑α-alanine acid chlorides, followed by cyclization under mild conditions, leads to target 3-methyl‑7-nitro‑1,2-dihydro‑3H‑1,4-benzodiazepin‑2-ones characterized by high optical purity. It is noteworthy that these reactions allow the coupling of acid chlorides derived from stereospecific α-alanines with weakly reactive 5-nitro derivatives of 2-aminobenzophenone without racemization. It is important to note that the acid chloride hydrochlorides of optically active α-alanines, which are chemically unstable and extremely sensitive to moisture, are used as building blocks in the work. In this case, acid chlorides of individual antipodes of L- or D‑α-alanine were synthesized in absolute chloroform using phosphorus pentachloride and the products were isolated by simple filtration of precipitates, without applying additional purification to them. The structure of the title compound was confirmed by spectroscopy 1H and 13C NMR, and FAB mass spectrometry methods, purity was controlled by HPLC. To analyze the optical purity of the1,2-dihydro‑3H‑1,4-benzodiazepines synthesized in this work, HPLC was applied using stationary chiral phase CiraDex®. This simple preparation method is of potential practical importance for the design and synthesis of optically pure enantiomers of various 3-alkyl derivatives of 1,2-dihydro‑3H‑1,4-benzodiazepin‑2-ones with a wide spectrum of biological activity.
{"title":"SYNTHESIS METHOD OF OPTICALLY PURE ENANTIOMERS OF 5-ARYL SUBSTITUTED3-METHYL‑7- NITRO‑1,2-DIHYDRO‑3H‑1,4-BENZODIAZEPIN‑2-ONES","authors":"A. Y. Kornylov, A. A. Krysko, O. Krysko, S. E. Sambursky","doi":"10.18524/2304-0947.2022.2(82).264890","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.2(82).264890","url":null,"abstract":"The aim of this work is to develop a simple, fast and efficient method for the synthesis of optically pure enantiomers of some 5-aryl-substituted 3-methyl‑7-nitro‑1,2-dihydro‑3H‑1,4-benzodiazepin‑2-ones using simple reagents. In the course of the study, we found that the interaction of 2-amino‑5-nitrobenzophenone or 2-amino‑2’-chloro‑5-nitrobenzophenone with optically active L- or D‑α-alanine N‑carboxyanhydrides in the presence of two equivalents of trifluoroacetic acid does not leads to the formation of the corresponding reaction intermediates (2-amino-N-(2-benzoylphenyl)propanamide), even when refluxed for 24 hours in xylene. Acylation of 5-nitro‑2-aminobenzophenones with hydrochlorides of L- or D‑α-alanine acid chlorides, followed by cyclization under mild conditions, leads to target 3-methyl‑7-nitro‑1,2-dihydro‑3H‑1,4-benzodiazepin‑2-ones characterized by high optical purity. It is noteworthy that these reactions allow the coupling of acid chlorides derived from stereospecific α-alanines with weakly reactive 5-nitro derivatives of 2-aminobenzophenone without racemization. It is important to note that the acid chloride hydrochlorides of optically active α-alanines, which are chemically unstable and extremely sensitive to moisture, are used as building blocks in the work. In this case, acid chlorides of individual antipodes of L- or D‑α-alanine were synthesized in absolute chloroform using phosphorus pentachloride and the products were isolated by simple filtration of precipitates, without applying additional purification to them. The structure of the title compound was confirmed by spectroscopy 1H and 13C NMR, and FAB mass spectrometry methods, purity was controlled by HPLC. To analyze the optical purity of the1,2-dihydro‑3H‑1,4-benzodiazepines synthesized in this work, HPLC was applied using stationary chiral phase CiraDex®. This simple preparation method is of potential practical importance for the design and synthesis of optically pure enantiomers of various 3-alkyl derivatives of 1,2-dihydro‑3H‑1,4-benzodiazepin‑2-ones with a wide spectrum of biological activity.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82667084","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 : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264883
V. Zinchenko, V. V. Menchuk, L. V. Sadkovska
From the thermodynamic standpoint, the stability of valence states in binary and complex oxides of d- and p-metals is considered by the change in the free Gibbs energy in the oxidation-reduction reactions. The presence of a correlation between a valence state of a metal and the electronegativity of its oxide has been established. Thus, metals in the lowest valence state M(II) – (Mn(II), Fe(II), Tl(I), Pb(II)) have low (less than 1.5 еV1/2/O2-) values of electronegativity and reveal predominantly basic properties. Their oxides are undergone to oxidation reactions with increasing valence states of M(III) or M(IV) and, accordingly, electronegativities with conversion to amphoteric oxides. The essence of the stabilization of the lowest state is the binding of binary oxides of metals in complex oxide compounds (oxosalts), and the stabilization can be represented as the difference between the electronegativities of oxides. It is established that with a certain difference of electronegativities the stabilization of the valence state increases significantly, and in some cases complete stability is realized. The motive force of the process of stabilization of the lower valence state is the increase of the ionicity of the bond in the complex oxide compared to the binary oxide. Instead, metal oxides in the highest valence states (M(IV), M(VI)) have high (above 2 еV1/2/O2-) values of electronegativities and exhibit mainly acidic properties. Under reducing conditions, they undergo reduction to lower valence states (M(III), (M(IV)), again acquiring amphoteric properties to form complex oxide compounds with higher oxides. Although the stability values of the valence states of these oxides are quite high at normal amphoteric pressure, their further stabilization is possible. The essence of the process, as in the previous part, is to increase the ionicity of the bonds between the low-valent metal and polyhedron, and most importantly – to increase the covalence of the high-valent metal-oxygen bonds in the latter. It should be noted that the stabilization effect in this case also depends on the difference between the electronegativities of the oxides – basic and stabilizing. Thus, using data from the electronegativities of metal oxides, which show the instability of a valence state, it is possible to effectively carry out the processes of their stabilization.
从热力学的角度出发，用氧化还原反应中自由吉布斯能的变化来考虑d-金属和p-金属的二元和络合氧化物价态的稳定性。金属的价态与其氧化物的电负性之间存在着一种相互关系。因此，处于最低价态M(II) - (Mn(II)， Fe(II)， Tl(I)， Pb(II))的金属具有较低的电负性(小于1.5 μ l /2/O2-)值，并显示出主要的碱性性质。它们的氧化物发生氧化反应，使M(III)或M(IV)的价态增加，相应地，电负性转变为两性氧化物。最低态稳定化的实质是金属二元氧化物在复合氧化物(氧盐)中的结合，稳定化可以用氧化物的电负性差来表示。结果表明，当电负性相差一定时，价态的稳定性显著提高，在某些情况下可以实现完全稳定。低价态稳定过程的动力是复合氧化物中键的离子性比二元氧化物的增加。相反，价态最高的金属氧化物(M(IV)， M(VI))具有较高的电负性值(高于2 μ v /2/O2-)，主要表现为酸性。在还原条件下，它们被还原成更低的价态(M(III)， (M(IV))，再次获得两性性质，形成具有更高氧化物的复杂氧化物化合物。虽然这些氧化物的价态在正常两性压力下的稳定值相当高，但它们的进一步稳定是可能的。正如前文所述，这个过程的本质是增加低价金属与多面体之间键的离子性，最重要的是增加高价金属与多面体中氧键的共价性。应该注意的是，在这种情况下的稳定效果还取决于氧化物的电负性-碱性和稳定性之间的差异。因此，利用显示价态不稳定性的金属氧化物的电负性数据，可以有效地进行它们的稳定化过程。
{"title":"ELECTRONEGATIVITY AS A FACTOR OF STABILIZATION OF VALENCE STATES IN COMPLEX OXIDES OF p- AND d-ELEMENTS","authors":"V. Zinchenko, V. V. Menchuk, L. V. Sadkovska","doi":"10.18524/2304-0947.2022.2(82).264883","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.2(82).264883","url":null,"abstract":"From the thermodynamic standpoint, the stability of valence states in binary and complex oxides of d- and p-metals is considered by the change in the free Gibbs energy in the oxidation-reduction reactions. The presence of a correlation between a valence state of a metal and the electronegativity of its oxide has been established. Thus, metals in the lowest valence state M(II) – (Mn(II), Fe(II), Tl(I), Pb(II)) have low (less than 1.5 еV1/2/O2-) values of electronegativity and reveal predominantly basic properties. Their oxides are undergone to oxidation reactions with increasing valence states of M(III) or M(IV) and, accordingly, electronegativities with conversion to amphoteric oxides. The essence of the stabilization of the lowest state is the binding of binary oxides of metals in complex oxide compounds (oxosalts), and the stabilization can be represented as the difference between the electronegativities of oxides. It is established that with a certain difference of electronegativities the stabilization of the valence state increases significantly, and in some cases complete stability is realized. The motive force of the process of stabilization of the lower valence state is the increase of the ionicity of the bond in the complex oxide compared to the binary oxide. Instead, metal oxides in the highest valence states (M(IV), M(VI)) have high (above 2 еV1/2/O2-) values of electronegativities and exhibit mainly acidic properties. Under reducing conditions, they undergo reduction to lower valence states (M(III), (M(IV)), again acquiring amphoteric properties to form complex oxide compounds with higher oxides. Although the stability values of the valence states of these oxides are quite high at normal amphoteric pressure, their further stabilization is possible. The essence of the process, as in the previous part, is to increase the ionicity of the bonds between the low-valent metal and polyhedron, and most importantly – to increase the covalence of the high-valent metal-oxygen bonds in the latter. It should be noted that the stabilization effect in this case also depends on the difference between the electronegativities of the oxides – basic and stabilizing. Thus, using data from the electronegativities of metal oxides, which show the instability of a valence state, it is possible to effectively carry out the processes of their stabilization.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82475001","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 : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264875
T. Kiose, Т. L. Rakitskaya, A. Truba, A. Ennan, О. S. Rakitskiy
Oxide and metal complex catalysts for low temperature gas-phase oxidation of carbon monoxide by air oxygen lose their activity under the action of chemical poisons such as SO2, H2S, PH3, H2O. We have developed a highly efficient Wacker-type catalyst in which the carrier is a carbon fiber material (CFM), the precursor of which was cellulose hydrate. For such a catalyst, there are no studies on the effect of catalytic poisons, namely SO2 and H2O, on its activity in the reaction of low-temperature oxidation of CO with oxygen. The morphology, elemental composition and adsorption properties of carbon fiber material and carbon monoxide oxidation catalyst are investigated. Pd(II)-Cu(II)/CFM relative to water vapor and sulfur dioxide, as well as their effect on the protective properties of the catalyst. SEM studies (scanning electron microscope) confirmed the morphology typical of CFM and found very small agglomerates in the case of the catalyst, which are formed by paratacamite Cu2(OH)3Cl crystallites caused by oxidation of the carbon surface by palladium (II). When applying the catalyst components, the fibers do not lose their shape, but the surface of the fibers is unevenly covered with impurities. Palladium (II) is reduced by a carbon surface by about 10%, agglomerates [Pdo]n are not observed, while fiber erosion increases and very small agglomerates are formed on the surface, which are formed by Cu2(OH)3Cl phase crystallites. Carbon material is generally characterized by a high content of carbon and oxygen, but their distribution is heterogeneous. In the analysis of adsorption isotherms, which are classified as type IV, it was found that CFM and the catalyst based on it belong to the microporous samples. It is proved that only at the relative humidity of the gas-air mixture, which is equal to 30% C < MPCSO2 (20 mg/m3). Catalyst poisoning does not disrupt the catalytic process, but with increasing amount of absorbed sulfur dioxide (QSO2 ) the degree of conversion of carbon monoxide decreases and especially sharply at the absorption of 10.3⋅10–4 mol SO2. Thus, the results obtained on the effect of relative humidity and the amount of adsorbed by the catalyst SO2 on the activity of Pd(II)-Cu(II)/CFM catalyst, indicate a significant reduction in the degree of conversion of carbon monoxide. Therefore, in the case of applying of such a catalyst, for example in respiratory protection against CO, a preliminary stage of absorption of moisture and sulfur dioxide should be provided.
{"title":"EFFECT OF CERTAIN CATALYTIC POISONS ON THE ACTIVITY OF CUPRUM-PALADIUM COMPLEXES APPLIED ON CARBON MATERIAL IN THE REACTION IN THE REACTION OF CARBON MONOXIDE OXIDATION BY AIR OXYGEN","authors":"T. Kiose, Т. L. Rakitskaya, A. Truba, A. Ennan, О. S. Rakitskiy","doi":"10.18524/2304-0947.2022.2(82).264875","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.2(82).264875","url":null,"abstract":"Oxide and metal complex catalysts for low temperature gas-phase oxidation of carbon monoxide by air oxygen lose their activity under the action of chemical poisons such as SO2, H2S, PH3, H2O. We have developed a highly efficient Wacker-type catalyst in which the carrier is a carbon fiber material (CFM), the precursor of which was cellulose hydrate. For such a catalyst, there are no studies on the effect of catalytic poisons, namely SO2 and H2O, on its activity in the reaction of low-temperature oxidation of CO with oxygen. The morphology, elemental composition and adsorption properties of carbon fiber material and carbon monoxide oxidation catalyst are investigated. Pd(II)-Cu(II)/CFM relative to water vapor and sulfur dioxide, as well as their effect on the protective properties of the catalyst. SEM studies (scanning electron microscope) confirmed the morphology typical of CFM and found very small agglomerates in the case of the catalyst, which are formed by paratacamite Cu2(OH)3Cl crystallites caused by oxidation of the carbon surface by palladium (II). When applying the catalyst components, the fibers do not lose their shape, but the surface of the fibers is unevenly covered with impurities. Palladium (II) is reduced by a carbon surface by about 10%, agglomerates [Pdo]n are not observed, while fiber erosion increases and very small agglomerates are formed on the surface, which are formed by Cu2(OH)3Cl phase crystallites. Carbon material is generally characterized by a high content of carbon and oxygen, but their distribution is heterogeneous. In the analysis of adsorption isotherms, which are classified as type IV, it was found that CFM and the catalyst based on it belong to the microporous samples. It is proved that only at the relative humidity of the gas-air mixture, which is equal to 30% C < MPCSO2 (20 mg/m3). Catalyst poisoning does not disrupt the catalytic process, but with increasing amount of absorbed sulfur dioxide (QSO2 ) the degree of conversion of carbon monoxide decreases and especially sharply at the absorption of 10.3⋅10–4 mol SO2. Thus, the results obtained on the effect of relative humidity and the amount of adsorbed by the catalyst SO2 on the activity of Pd(II)-Cu(II)/CFM catalyst, indicate a significant reduction in the degree of conversion of carbon monoxide. Therefore, in the case of applying of such a catalyst, for example in respiratory protection against CO, a preliminary stage of absorption of moisture and sulfur dioxide should be provided.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"179 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80052674","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 : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264886
K. Pliuta, D. Snigur
In the current study, using a carbon-paste electrode modified with β-cyclodextrin oligosaccharide, the oxidation mechanism of some useful food azo dyes as Sunset Yellow FCF, Tartrazine, Allura Red AC, Carmoisine, Ponceau 4R was established. Cyclic voltammetry was used to investigation redox behaviour of studied food azo dyes (Sunset Yellow FCF, Tartrazine, Allura Red AC, Carmoisine, Ponceau 4R). It was established that such dyes as Sunset Yellow FCF and Ponceau 4R are oxidized quasi-reversibly, and such as Tartrazine, Carmoisine and Allura Red AC are completely irreversibly oxidized. It was noted that for all dyes, except Tartrazine, after oxidation on a cyclic voltammogram, a new reversibly redox pair is formed. This may indicate the formation of new electroactive fragments during the oxidation of azo dyes (Sunset Yellow FCF, Allura Red AC, Carmoisine, Ponceau 4R). Based on the conducted studies of the effect of pH and scanning rate on the oxidation potential of studied azo dyes, it was established that 2 electrons and 1 proton participate in the oxidation process for all dyes, except for Carmoisine, for which oxidation takes place with the participation of 1 proton and 1 electron. Based on the obtained information, as well as using information from our previous studies on the redox behavior of azo dyes (Sunset Yellow FCF, Tartrazine, Allura Red AC, Carmoisine, Ponceau 4R) on carbon-paste electrode modified by silica impregnated with cetylpyridinium chloride cationic surfactant, a scheme for the oxidation of azo dyes was proposed. According to the scheme, oxidation takes place with the participation of an irreversible chemical reaction, which leads to the further rearrangement of bonds with the breaking of the azo group of dyes and the formation of new electroactive fragments.
本研究采用β-环糊精低聚糖修饰碳糊电极，研究了落日黄FCF、酒黄、诱惑红AC、胭脂红、Ponceau 4R等常用食品偶氮染料的氧化机理。采用循环伏安法研究了所研究的食品偶氮染料(日落黄FCF、酒黄石、诱惑红AC、卡莫辛、Ponceau 4R)的氧化还原行为。确定了日落黄FCF、Ponceau 4R等染料为准可逆氧化，酒石黄、胭脂红、诱惑红AC等染料为完全不可逆氧化。除酒黄石外，所有染料在循环伏安图上氧化后，形成一个新的可逆氧化还原对。这可能表明偶氮染料(Sunset Yellow FCF, Allura Red AC, Carmoisine, Ponceau 4R)氧化过程中形成了新的电活性片段。通过对pH和扫描速率对偶氮染料氧化电位的影响的研究，确定了除卡莫辛外，所有染料的氧化过程都有2个电子和1个质子参与，卡莫辛是1个质子和1个电子参与氧化。在此基础上，结合前人对偶氮染料(Sunset Yellow FCF、酒石黄、Allura Red AC、Carmoisine、Ponceau 4R)在碳糊电极上氧化还原行为的研究结果，提出了一种偶氮染料的氧化方案。根据该方案，氧化是在不可逆化学反应的参与下发生的，该化学反应导致染料的偶氮基团断裂，从而导致键的进一步重排，并形成新的电活性片段。
{"title":"TO THE PROBLEM ON THE OXIDATION MECHANISM OF AZO DYES ON MODIFIED CARBON-PASTE ELECTRODES","authors":"K. Pliuta, D. Snigur","doi":"10.18524/2304-0947.2022.2(82).264886","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.2(82).264886","url":null,"abstract":"In the current study, using a carbon-paste electrode modified with β-cyclodextrin oligosaccharide, the oxidation mechanism of some useful food azo dyes as Sunset Yellow FCF, Tartrazine, Allura Red AC, Carmoisine, Ponceau 4R was established. Cyclic voltammetry was used to investigation redox behaviour of studied food azo dyes (Sunset Yellow FCF, Tartrazine, Allura Red AC, Carmoisine, Ponceau 4R). It was established that such dyes as Sunset Yellow FCF and Ponceau 4R are oxidized quasi-reversibly, and such as Tartrazine, Carmoisine and Allura Red AC are completely irreversibly oxidized. It was noted that for all dyes, except Tartrazine, after oxidation on a cyclic voltammogram, a new reversibly redox pair is formed. This may indicate the formation of new electroactive fragments during the oxidation of azo dyes (Sunset Yellow FCF, Allura Red AC, Carmoisine, Ponceau 4R). Based on the conducted studies of the effect of pH and scanning rate on the oxidation potential of studied azo dyes, it was established that 2 electrons and 1 proton participate in the oxidation process for all dyes, except for Carmoisine, for which oxidation takes place with the participation of 1 proton and 1 electron. Based on the obtained information, as well as using information from our previous studies on the redox behavior of azo dyes (Sunset Yellow FCF, Tartrazine, Allura Red AC, Carmoisine, Ponceau 4R) on carbon-paste electrode modified by silica impregnated with cetylpyridinium chloride cationic surfactant, a scheme for the oxidation of azo dyes was proposed. According to the scheme, oxidation takes place with the participation of an irreversible chemical reaction, which leads to the further rearrangement of bonds with the breaking of the azo group of dyes and the formation of new electroactive fragments.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87933088","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 : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264894
R. Khoma
In memory of Prof. Alim Abdul-Amidovich Ennan
{"title":"In memory of Prof. Alim Abdul-Amidovich Ennan","authors":"R. Khoma","doi":"10.18524/2304-0947.2022.2(82).264894","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.2(82).264894","url":null,"abstract":"In memory of Prof. Alim Abdul-Amidovich Ennan","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82230558","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 : 2022-11-16DOI: 10.18524/2304-0947.2022.2(82).264881
V. Zinchenko, O. Ieriomin, I. Stoyanova, G. Volchak, A. Babenko
The nature of the interaction was determined by the method of diffuse reflection (DR) spectroscopy and conclusions were made about the possible composition of the reaction products in the CeF3-EuF3-NaCl-KCl system. As a result of high-temperature (800 and 1100 °C) heat treatment of a mixture of CeF3 with EuF3 in the ratios 1: 1 and 1: 2, a significant change in the nature of the spectral curves of DR in UV and near IR-spectral ranges is observed. In the first of them, intense absorption was found in the entire spectral range, and more pronounced at higher EuF3 content. On the other hand, significant deformation and a sharp decrease in the intensity of the absorption band are observed on the spectral curves of the DR in the near IR range of the spectrum. The DR spectra of sintered samples in the UV range indicate the emergence of various valent states of Ce (III, IV) and Eu (II, III) with a predominance of Ce4+ and Eu2+ ions compared to Ce3+ and Eu3+. The decrease in the absorption intensity of Eu3+ ions due to 4f‑4f electronic transitions in the near-IR spectra is a direct confirmation of the oxidation-reduction processes occurring in the solid state system. These processes become even more pronounced when processing samples of systems in NaCl-KCl melt, even without pre-sintering. Thus, in the sample, which is a mechanical mixture of CeF3-EuF3 after treatment in the salt melt, the absorption in the near IR range on the DR spectra either disappears altogether (ratio 1: 1), or is a slight residue of F(R) at about 10–3 a. u.). The spectra of DR in the UV range also change dramatically, indicating a predominant content of Eu (II) compared to Eu (III). A similar effect on the nature of the DR spectrum is exerted by the processing of pre-sintered samples in the salt melt, namely, there is a change in the nature of the DR spectral curves both in the UV and in the near IR ranges of the spectrum. This indicates the deepening of the oxidation-reduction processes in the samples of the CeF3-EuF3-NaCl-KCl system with the participation of the salt melt. The increase in the ratio of CeF3-EuF3 from 1: 1 to 1: 2 contributes to above mentioned processes.
{"title":"DIFFUSE REFLECTION SPECTRA OF FROZEN SALT MELTS OF THE CeF3-EuF3-NaCl-KCl SYSTEMS","authors":"V. Zinchenko, O. Ieriomin, I. Stoyanova, G. Volchak, A. Babenko","doi":"10.18524/2304-0947.2022.2(82).264881","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.2(82).264881","url":null,"abstract":"The nature of the interaction was determined by the method of diffuse reflection (DR) spectroscopy and conclusions were made about the possible composition of the reaction products in the CeF3-EuF3-NaCl-KCl system. As a result of high-temperature (800 and 1100 °C) heat treatment of a mixture of CeF3 with EuF3 in the ratios 1: 1 and 1: 2, a significant change in the nature of the spectral curves of DR in UV and near IR-spectral ranges is observed. In the first of them, intense absorption was found in the entire spectral range, and more pronounced at higher EuF3 content. On the other hand, significant deformation and a sharp decrease in the intensity of the absorption band are observed on the spectral curves of the DR in the near IR range of the spectrum. The DR spectra of sintered samples in the UV range indicate the emergence of various valent states of Ce (III, IV) and Eu (II, III) with a predominance of Ce4+ and Eu2+ ions compared to Ce3+ and Eu3+. The decrease in the absorption intensity of Eu3+ ions due to 4f‑4f electronic transitions in the near-IR spectra is a direct confirmation of the oxidation-reduction processes occurring in the solid state system. These processes become even more pronounced when processing samples of systems in NaCl-KCl melt, even without pre-sintering. Thus, in the sample, which is a mechanical mixture of CeF3-EuF3 after treatment in the salt melt, the absorption in the near IR range on the DR spectra either disappears altogether (ratio 1: 1), or is a slight residue of F(R) at about 10–3 a. u.). The spectra of DR in the UV range also change dramatically, indicating a predominant content of Eu (II) compared to Eu (III). A similar effect on the nature of the DR spectrum is exerted by the processing of pre-sintered samples in the salt melt, namely, there is a change in the nature of the DR spectral curves both in the UV and in the near IR ranges of the spectrum. This indicates the deepening of the oxidation-reduction processes in the samples of the CeF3-EuF3-NaCl-KCl system with the participation of the salt melt. The increase in the ratio of CeF3-EuF3 from 1: 1 to 1: 2 contributes to above mentioned processes.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85030954","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 : 2022-06-05DOI: 10.18524/2304-0947.2022.1(81).255831
V. Zinchenko, V. V. Menchuk
Сoncepts of acidity-basicity for systems of different types are considered. The application of the parameter of effective electronegativity for estimating the acidity is proposed, the value of which is calculated from the thermochemical data of acid-base reactions in the condensed state (liquid, solid). The basis is the value of electronegativity of SO3, which should be equal to 3.00. Its values are in the range of 2.0 ÷ 3.1 for acid oxides and 0.3 ÷ 1.6 for oxides of basic nature. A significant group consists of oxides of bifunctional nature (amphoteric oxides) whose electronegativity values are 1.7 ÷ 1.9. A characteristic feature of amphoteric oxides is the manifestation of two values of electronegativity, corresponding to acid and basic functions. It is shown that the behavior of water as a characteristic amphoteric oxide is similar. Some predominance of acidic properties of water over the basic ones is shown and the possible reason for such behavior is discussed. To take into account this phenomenon, a method of converting the electronegativity of water to its value for the oxide partner during hydration is proposed. The values of electronegativity of hydroxides of elements (acidic, basic and amphoteric) were carried out by averaging them for components on the principle of additivity, the correctness of which is confirmed by direct calculations for individual hydroxides. It is shown that in the formation of hydroxides of elements there is a convergence between the values of electronegativities of acidic and basic oxides, ie the reduction of the former and the growth of the latter. Instead, in the case of amphoteric hydroxides, no noticeable changes in electronegativities compared to the original oxides occur. There is a qualitative correlation between the electronegativity of the hydroxides of the elements and the acidity (basicity) constants of their aqueous solutions, which is a reflection of their strength. This allows predicting the strength of acids and bases based on the electronegativity of hydroxides.
{"title":"ELECTRONEGATIVITY AND STRENGTH OF ACIDS AND BASES IN AQUEOUS SOLUTIONS","authors":"V. Zinchenko, V. V. Menchuk","doi":"10.18524/2304-0947.2022.1(81).255831","DOIUrl":"https://doi.org/10.18524/2304-0947.2022.1(81).255831","url":null,"abstract":"Сoncepts of acidity-basicity for systems of different types are considered. The application of the parameter of effective electronegativity for estimating the acidity is proposed, the value of which is calculated from the thermochemical data of acid-base reactions in the condensed state (liquid, solid). The basis is the value of electronegativity of SO3, which should be equal to 3.00. Its values are in the range of 2.0 ÷ 3.1 for acid oxides and 0.3 ÷ 1.6 for oxides of basic nature. A significant group consists of oxides of bifunctional nature (amphoteric oxides) whose electronegativity values are 1.7 ÷ 1.9. A characteristic feature of amphoteric oxides is the manifestation of two values of electronegativity, corresponding to acid and basic functions. It is shown that the behavior of water as a characteristic amphoteric oxide is similar. Some predominance of acidic properties of water over the basic ones is shown and the possible reason for such behavior is discussed. To take into account this phenomenon, a method of converting the electronegativity of water to its value for the oxide partner during hydration is proposed. The values of electronegativity of hydroxides of elements (acidic, basic and amphoteric) were carried out by averaging them for components on the principle of additivity, the correctness of which is confirmed by direct calculations for individual hydroxides. It is shown that in the formation of hydroxides of elements there is a convergence between the values of electronegativities of acidic and basic oxides, ie the reduction of the former and the growth of the latter. Instead, in the case of amphoteric hydroxides, no noticeable changes in electronegativities compared to the original oxides occur. There is a qualitative correlation between the electronegativity of the hydroxides of the elements and the acidity (basicity) constants of their aqueous solutions, which is a reflection of their strength. This allows predicting the strength of acids and bases based on the electronegativity of hydroxides.","PeriodicalId":19451,"journal":{"name":"Odesa National University Herald. Chemistry","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86953328","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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