The thermodynamic and kinetic peculiarities of metal nucleation under galvanostatic conditions are considered. The alternative expressions for supersaturation in electrochemical systems in terms of overall overpotential (Kaischew, Budevski, Malev, Polukarov, de Levi at al.) or crystallization overpotential (Fischer, Volmer, Schottky, Vetter, Lorenz, Gerischer at al.) are discussed. It is shown that incorrect use of expression for supersaturation in terms of overall overpotential leads some authors to unreasonable interpretation of experimental data. This leads to negative impact on electrochemical nucleation theory development. Some kinetic theories (Schottky, Baraboshkin, Kashchiev) take into account changes of supersaturation and atoms consumption by growing nuclei during the current pulse. However this corrections are difficult to identify. Computer modeling of galvanostatic phase formation (Isaev, Baraboshkin, Volegov) correctly describes the time dependence of the main parameters of nucleation. Moreover, applying of this approach in data processing of experimental overpotential transients requires the kinetic and thermodynamic constants of the process determination. Gutsov`s kinetic model is still more suitable for the analysis of experimental overpotential transients, because this theory takes into account the influence of crystallization overpotential on the rate of phase formation.
{"title":"Discussion aspects of the theory of galvanostatic phase formation","authors":"Iurii Kryshtop, V. Trofimenko","doi":"10.15421/081414","DOIUrl":"https://doi.org/10.15421/081414","url":null,"abstract":"The thermodynamic and kinetic peculiarities of metal nucleation under galvanostatic conditions are considered. The alternative expressions for supersaturation in electrochemical systems in terms of overall overpotential (Kaischew, Budevski, Malev, Polukarov, de Levi at al.) or crystallization overpotential (Fischer, Volmer, Schottky, Vetter, Lorenz, Gerischer at al.) are discussed. It is shown that incorrect use of expression for supersaturation in terms of overall overpotential leads some authors to unreasonable interpretation of experimental data. This leads to negative impact on electrochemical nucleation theory development. Some kinetic theories (Schottky, Baraboshkin, Kashchiev) take into account changes of supersaturation and atoms consumption by growing nuclei during the current pulse. However this corrections are difficult to identify. Computer modeling of galvanostatic phase formation (Isaev, Baraboshkin, Volegov) correctly describes the time dependence of the main parameters of nucleation. Moreover, applying of this approach in data processing of experimental overpotential transients requires the kinetic and thermodynamic constants of the process determination. Gutsov`s kinetic model is still more suitable for the analysis of experimental overpotential transients, because this theory takes into account the influence of crystallization overpotential on the rate of phase formation.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"16-22"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67580329","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}
M. Al-Shwaiyat, T. Denisenko, Sergey V. Zaruba, A. Vishnikin, L. P. Tsiganok, V. Andruch, Y. Bazel
New approach has been proposed for the simultaneous determination of two reducing agents based on the dependence of their reaction rate with 18-molybdo-2-phosphate heteropoly complex on pH. The method was automated using the manifold typical for the sequential analysis method. Ascorbic acid and rutin were determined by successive injection of two samples acidified to different pH. The linear range for rutin determination was 0.6-20 mg/L and the detection limit was 0.2 mg/L (l = 1 cm). The determination of rutin was possible in the presence of up to a 20-fold excess of ascorbic acid. The method was successfully applied to the determination of ascorbic acid and rutin in ascorutin tablets. The applicability of the proposed method for the determination of total polyphenol content in natural plant samples was shown.
{"title":"SIMULTANEOUS DETERMINATION OF TWO ACTIVE COMPONENTS OF PHARMACEUTICAL PREPARATIONS BY SEQUENTIAL INJECTION METHOD USING HETEROPOLY COMPLEXES","authors":"M. Al-Shwaiyat, T. Denisenko, Sergey V. Zaruba, A. Vishnikin, L. P. Tsiganok, V. Andruch, Y. Bazel","doi":"10.15421/081408","DOIUrl":"https://doi.org/10.15421/081408","url":null,"abstract":"New approach has been proposed for the simultaneous determination of two reducing agents based on the dependence of their reaction rate with 18-molybdo-2-phosphate heteropoly complex on pH. The method was automated using the manifold typical for the sequential analysis method. Ascorbic acid and rutin were determined by successive injection of two samples acidified to different pH. The linear range for rutin determination was 0.6-20 mg/L and the detection limit was 0.2 mg/L (l = 1 cm). The determination of rutin was possible in the presence of up to a 20-fold excess of ascorbic acid. The method was successfully applied to the determination of ascorbic acid and rutin in ascorutin tablets. The applicability of the proposed method for the determination of total polyphenol content in natural plant samples was shown.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"23-29"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67579767","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}
Alexander B. Surovtcev, K. Kovalenko, N. Kuzmenko, Sergey G. Bondarenko
Приведены результаты исследований по получению пастообразных высоконаполненных композиций и оценке их реологических свойств с использованием ротационного вискозиметра «Реотест-2» на системе конус плоскость. В состав композиций вводили олигомерный каучук СКД-ГТР в качестве связующего, поверхностно-активное вещество (ПАВ) и дисперсный наполнитель. Выполнена оценка седиментационной стойкости композиций и их текучести в интервале напряжений сдвига 1–30 кПа и температур от 30 до 50°С. По результатам оценки влияния концентрационной зависимости ПАВ на показатель вязкости показано, что целесообразно его введение в пастообразную композицию на уровне 0.5 мас. %. Для рассмотренного в работе малополярного олигомерного диенового каучука более эффективное снижение вязкости пастообразной композиции обеспечивают полипропиленгликоли, особенно в среднем интервале напряжений сдвига, который в основном может быть использован на практике. Незначительно уступают им титанорганические производные олигомерных полиоксипропиленгликолей. Наибольший эффект снижения вязкости для композиций достигнут при использовании олигомерного ППГ с молекулярной массой 480, в данном случае вязкость композиции находится на уровне 10 Па ⋅ с для весьма широкого интервала напряжений сдвига.
{"title":"INFLUENCE OF THE NATURE OF SURFACE-ACTIVE SUBSTANCES ON RHEOLOGY OF HIGH-FILLED PASTELIKE COMPOSITIONS ON A BASE ON LIQUID DIENE RUBBER AND DISPERSE FILLER","authors":"Alexander B. Surovtcev, K. Kovalenko, N. Kuzmenko, Sergey G. Bondarenko","doi":"10.15421/081415","DOIUrl":"https://doi.org/10.15421/081415","url":null,"abstract":"Приведены результаты исследований по получению пастообразных высоконаполненных композиций и оценке их реологических свойств с использованием ротационного вискозиметра «Реотест-2» на системе конус плоскость. В состав композиций вводили олигомерный каучук СКД-ГТР в качестве связующего, поверхностно-активное вещество (ПАВ) и дисперсный наполнитель. Выполнена оценка седиментационной стойкости композиций и их текучести в интервале напряжений сдвига 1–30 кПа и температур от 30 до 50°С. По результатам оценки влияния концентрационной зависимости ПАВ на показатель вязкости показано, что целесообразно его введение в пастообразную композицию на уровне 0.5 мас. %. Для рассмотренного в работе малополярного олигомерного диенового каучука более эффективное снижение вязкости пастообразной композиции обеспечивают полипропиленгликоли, особенно в среднем интервале напряжений сдвига, который в основном может быть использован на практике. Незначительно уступают им титанорганические производные олигомерных полиоксипропиленгликолей. Наибольший эффект снижения вязкости для композиций достигнут при использовании олигомерного ППГ с молекулярной массой 480, в данном случае вязкость композиции находится на уровне 10 Па ⋅ с для весьма широкого интервала напряжений сдвига.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"76-81"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67580459","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}
K. E. Varlan, Svetlana A. Plotichkina, Aleksandra L. Kuzmenko
The film materials with ion-exchanged properties on the basis of the polymer, obtained by condensation of oligoepichlorohydrined epoxide and piperazine with the subsequent chemical modification have been synthesized. Compounds which have different thermodynamic affinity with the polymer and each other have been used as modifiers. It has been shown that the possibility of overcoming the lack of compatibility of the components by selection of the order of their combination. The result of the combination can be predicted by the Hildebrand parameter values of the ingredients, intermediate products and prepolymers based on them. The properties of synthesized materials can be adjusted by selection of combinations of chemical modifiers: toluilenediisocyanate, epoxyed soybean oil and tetraethoxysilane.
{"title":"Іонообмінні плівкові матеріали на основі олігоепіхлоргідринового епоксиду і піперазину","authors":"K. E. Varlan, Svetlana A. Plotichkina, Aleksandra L. Kuzmenko","doi":"10.15421/081413","DOIUrl":"https://doi.org/10.15421/081413","url":null,"abstract":"The film materials with ion-exchanged properties on the basis of the polymer, obtained by condensation of oligoepichlorohydrined epoxide and piperazine with the subsequent chemical modification have been synthesized. Compounds which have different thermodynamic affinity with the polymer and each other have been used as modifiers. It has been shown that the possibility of overcoming the lack of compatibility of the components by selection of the order of their combination. The result of the combination can be predicted by the Hildebrand parameter values of the ingredients, intermediate products and prepolymers based on them. The properties of synthesized materials can be adjusted by selection of combinations of chemical modifiers: toluilenediisocyanate, epoxyed soybean oil and tetraethoxysilane.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"71-75"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67580639","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}
Tatiana S. Chmilenko, Lidiya A. Ivanitsa, F. Chmilenko
Предложена аналитическая система для определения полигексаметиленгуанидиний хлорида (ПГМГ) с Мо(VI) и дисульфофенилфлуороном в среде NaNO 3 . Соотношение компонентов в тройных комплексах НФФ:ПГМГ:Мо(VI) определены по тройной диаграмме Гиббса-Розенбома и составили 3:1:1 (520 нм ) и 6:3:1 (570 нм ). В тройной системе также образуются ассоциат ПМГМ:НФФ с соотношением 1:2 и макрометаллохелат ПГМГ⋅2Mo(VI). Методика позволяет определять ПГМГ по градуировочной характеристике второго порядка в концентрационном интервале 0.1–2.0 мг/л , предел обнаружения составляет 0.03 мг/л . Определению не мешают такие металлы как Cu(II), V(IV), W(VI), Al(III), Co(II). Статистическая обработка была проведена в соответствии с ДСТУ ISO 8466-1-2001 и ДСТУ ISO 8466-2-2001.
{"title":"Statistical characteristics of spectrophotometric method for polyhexamethyleneguanidinedetermining","authors":"Tatiana S. Chmilenko, Lidiya A. Ivanitsa, F. Chmilenko","doi":"10.15421/081402","DOIUrl":"https://doi.org/10.15421/081402","url":null,"abstract":"Предложена аналитическая система для определения полигексаметиленгуанидиний хлорида (ПГМГ) с Мо(VI) и дисульфофенилфлуороном в среде NaNO 3 . Соотношение компонентов в тройных комплексах НФФ:ПГМГ:Мо(VI) определены по тройной диаграмме Гиббса-Розенбома и составили 3:1:1 (520 нм ) и 6:3:1 (570 нм ). В тройной системе также образуются ассоциат ПМГМ:НФФ с соотношением 1:2 и макрометаллохелат ПГМГ⋅2Mo(VI). Методика позволяет определять ПГМГ по градуировочной характеристике второго порядка в концентрационном интервале 0.1–2.0 мг/л , предел обнаружения составляет 0.03 мг/л . Определению не мешают такие металлы как Cu(II), V(IV), W(VI), Al(III), Co(II). Статистическая обработка была проведена в соответствии с ДСТУ ISO 8466-1-2001 и ДСТУ ISO 8466-2-2001.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"30-35"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67580096","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}
The optimal conditions for the microextraction separation, preconcentration and spectrophotometric determination of sodium dodecyl sulfate (SDS) as an its ion associate (IA) with Quinaldine Red (QR) have been studied. Was tested a large number of organic solvents as extractants. Aliphatic hydrocarbons (hexane) extracted IA considerably weaker than, halogen and nitro derivatives of hydrocarbons (chlorobenzene, bromobenzene, nitrobenzene, chloroform, dichloroethane), extracted with IA and the simple salt of the dye. The best solvent found for the extraction of SDS was mixture of carbon tetrachloride with dichloroethane or chloroform that provided 10 to 50 fold concentration of SDS by microvolume of organic phase. The maximum extraction of SDS was achieved in the concentration range of QR 1.0∙10 –4 mol/l of QR after which the optical density does not change practically (excess dye remains in the aqueous phase). The dye of QR is highly stable in an alkaline environment, it can be used for the extraction of SDS in a wide pH range and rely on high selectivity determination. The pH range for maximum extraction of ion associate was 4–12. We found that 50000–100000-fold amounts F – , Cl – , Br – , NO 2 – , HCO 3 – , CH 3 COO – , SO 4 2– , 10000–20000-fold amounts NO 3 – , I – , HPO 4 2– , B 4 O 7 2– , IO 3 – , ClO 3 – , C 2 O 4 2– , 300-fold amounts ClO 4 – do not interfere with the determination of SDS. The molar ratio of SDS and QR determined by various spectrophotometric methods (isomolar series, Asmus, equilibrium shift) is 1:1. The limit of detection was 0.04 µg/ml. A new method of extraction-spectrophotometric determination was applied to the determination of anionic surfactants in various wastewater samples.
{"title":"Мікроекстракційне розділення, концентрування і спектрофотометричне визначення додецилсульфату натрію у вигляді іонного асоціату з хінальдиновим червоним","authors":"Vasylyna M. Lavra","doi":"10.15421/081404","DOIUrl":"https://doi.org/10.15421/081404","url":null,"abstract":"The optimal conditions for the microextraction separation, preconcentration and spectrophotometric determination of sodium dodecyl sulfate (SDS) as an its ion associate (IA) with Quinaldine Red (QR) have been studied. Was tested a large number of organic solvents as extractants. Aliphatic hydrocarbons (hexane) extracted IA considerably weaker than, halogen and nitro derivatives of hydrocarbons (chlorobenzene, bromobenzene, nitrobenzene, chloroform, dichloroethane), extracted with IA and the simple salt of the dye. The best solvent found for the extraction of SDS was mixture of carbon tetrachloride with dichloroethane or chloroform that provided 10 to 50 fold concentration of SDS by microvolume of organic phase. The maximum extraction of SDS was achieved in the concentration range of QR 1.0∙10 –4 mol/l of QR after which the optical density does not change practically (excess dye remains in the aqueous phase). The dye of QR is highly stable in an alkaline environment, it can be used for the extraction of SDS in a wide pH range and rely on high selectivity determination. The pH range for maximum extraction of ion associate was 4–12. We found that 50000–100000-fold amounts F – , Cl – , Br – , NO 2 – , HCO 3 – , CH 3 COO – , SO 4 2– , 10000–20000-fold amounts NO 3 – , I – , HPO 4 2– , B 4 O 7 2– , IO 3 – , ClO 3 – , C 2 O 4 2– , 300-fold amounts ClO 4 – do not interfere with the determination of SDS. The molar ratio of SDS and QR determined by various spectrophotometric methods (isomolar series, Asmus, equilibrium shift) is 1:1. The limit of detection was 0.04 µg/ml. A new method of extraction-spectrophotometric determination was applied to the determination of anionic surfactants in various wastewater samples.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"45-51"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67579884","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}
Derivatives of 1,5-benzodiazepines show various pharmacological activity. The presence of several reactive centers predetermines the possibility of reactions of 1,5-benzodiazepines both with electrophilic and nucleophilic reagents of various types. In addition, these compounds are suitable objects for the synthesis of new tricyclic systems containing a diazepinic cycle. In the article, the interaction of 4-phenyl- and 4-methyl-2,3-dihydro-1Н-1,5-benzodiazepine-2-ones with epichlorhydrin under various conditions is reported. It has been shown that under strongly basic conditions the reactions proceed at the nitrogen atom N 1 and N 1 -glycidyl-1,5- benzodiazepine-2-ones are obtained. The yields of products were 71-79%. Under soft basic conditions the reactions either did not proceed at all or were accompanied by the formation of side-products.
{"title":"Interaction of 2,3-dihydro-1H-benzodiazepinone-2 with epichlorhydrine","authors":"O. O. Gaponov, I. Tarabara","doi":"10.15421/081401","DOIUrl":"https://doi.org/10.15421/081401","url":null,"abstract":"Derivatives of 1,5-benzodiazepines show various pharmacological activity. The presence of several reactive centers predetermines the possibility of reactions of 1,5-benzodiazepines both with electrophilic and nucleophilic reagents of various types. In addition, these compounds are suitable objects for the synthesis of new tricyclic systems containing a diazepinic cycle. In the article, the interaction of 4-phenyl- and 4-methyl-2,3-dihydro-1Н-1,5-benzodiazepine-2-ones with epichlorhydrin under various conditions is reported. It has been shown that under strongly basic conditions the reactions proceed at the nitrogen atom N 1 and N 1 -glycidyl-1,5- benzodiazepine-2-ones are obtained. The yields of products were 71-79%. Under soft basic conditions the reactions either did not proceed at all or were accompanied by the formation of side-products.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"66-70"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67580034","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}
V. Kovalenko, Viktor F. Vargaliuk, Nadiia V. Stets
The article is devoted to the 140 anniversary of birth of the academician Lev Vladimirovich Pisarzhevsky, who was a distinguished chemical scientist, founder of the important area of chemical science – electronic chemistry. The article dwells upon the basic stages of the scientist’s life and creative art. The major results of scientific and educational activity during Dnipropetrovsk period of his life are reported. His role in the foundation of dnipropetrovsk scientific school of physical chemistry, as well as in its establishment, is shown. The pioneering role of the academician L. V. Pisarzhevsky in the formation of the theory of redox reactions as processes of returning and joining of electrons, which is generally accepted nowadays, as well as in the creation of backgrounds of modern electronic theories of catalysis, has been shown. L. V. Pisarzhevsky is characterized as a wonderful lecturer and teacher who expounded chemical material from the point of view of electronic conception and laid the foundation for the reformation of chemistry. The role of the academician L. V. Pisarzhevsky in the foundation of Dnipropetrovsk University and its chemical department, as well as in the organization of educational process in this establishment, is exposed using archive materials, which are kept in the funds of the State Archive of the Dnipropetrovsk region and of the historical museum of Oles Honchar Dnipropetrovsk National University.
这篇文章是为了纪念列夫·弗拉基米罗维奇·皮萨尔热夫斯基院士诞辰140周年，他是一位杰出的化学科学家，是化学科学重要领域——电子化学的创始人。这篇文章详述了这位科学家的生平和创造艺术的基本阶段。报告了他一生中第聂伯罗彼得罗夫斯克时期科学和教育活动的主要成果。他在第聂伯罗彼得罗夫斯克物理化学科学学院的建立中所起的作用，以及在它的建立中所起的作用。L. V. Pisarzhevsky院士在形成氧化还原反应为电子返回和连接过程的理论方面的开创性作用，这一理论在今天被普遍接受，以及在创造现代催化电子理论的背景方面，已经得到了证明。皮萨热夫斯基是一位杰出的讲师和教师，他从电子概念的角度阐述了化学材料，为化学的改革奠定了基础。学者L. V. Pisarzhevsky在第聂伯罗彼得罗夫斯克大学及其化学系的建立中的作用，以及在这所大学的教育过程中的组织，通过档案材料暴露出来，这些档案材料保存在第聂伯罗彼得罗夫斯克地区国家档案馆和oleshonchar第聂伯罗彼得罗夫斯克国立大学历史博物馆的资金中。
{"title":"Academician L. V. Pisarzhevsky is the founder of chemical science and education in Dnipropetrovsk university","authors":"V. Kovalenko, Viktor F. Vargaliuk, Nadiia V. Stets","doi":"10.15421/081403","DOIUrl":"https://doi.org/10.15421/081403","url":null,"abstract":"The article is devoted to the 140 anniversary of birth of the academician Lev Vladimirovich Pisarzhevsky, who was a distinguished chemical scientist, founder of the important area of chemical science – electronic chemistry. The article dwells upon the basic stages of the scientist’s life and creative art. The major results of scientific and educational activity during Dnipropetrovsk period of his life are reported. His role in the foundation of dnipropetrovsk scientific school of physical chemistry, as well as in its establishment, is shown. The pioneering role of the academician L. V. Pisarzhevsky in the formation of the theory of redox reactions as processes of returning and joining of electrons, which is generally accepted nowadays, as well as in the creation of backgrounds of modern electronic theories of catalysis, has been shown. L. V. Pisarzhevsky is characterized as a wonderful lecturer and teacher who expounded chemical material from the point of view of electronic conception and laid the foundation for the reformation of chemistry. The role of the academician L. V. Pisarzhevsky in the foundation of Dnipropetrovsk University and its chemical department, as well as in the organization of educational process in this establishment, is exposed using archive materials, which are kept in the funds of the State Archive of the Dnipropetrovsk region and of the historical museum of Oles Honchar Dnipropetrovsk National University.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"82-88"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67579789","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}
The ability to predict the redox properties is an important tool for study electron transfer processes occurring in the gas-phase (atmospheric chemistry) or in the condensed phase (electrochemistry, biochemistry). MPWB1K/6-31+G(d) and MPWB1K/tzvp theoretical models were found to provide reasonable accuracy of the prediction of ionization potentials for mono- and polycyclic azacompounds. The root mean square errors of the methods are 0.19 and 0.20, respectively. While the mean absolute deviation for both methods is the same and equals to 0.15 eV . These theoretical models were applied to predict ionization potentials for compounds not evaluated experimentally. Influence of substitutes and a number of nitrogen atoms on value of ionization potential was analyzed. Methyl-, and phenyl- groups, and fused benzo cycle decrease ionization potentials of N -heterocycles. Increase of amount of nitrogen atoms in five-membered cycles leads to significant enlargement of ionization potentials.
{"title":"THEORETICAL STUDY OF IONIZATION POTENTIALS OF N-HETEROCYCLIC COMPOUNDS","authors":"L. Sviatenko","doi":"10.15421/081410","DOIUrl":"https://doi.org/10.15421/081410","url":null,"abstract":"The ability to predict the redox properties is an important tool for study electron transfer processes occurring in the gas-phase (atmospheric chemistry) or in the condensed phase (electrochemistry, biochemistry). MPWB1K/6-31+G(d) and MPWB1K/tzvp theoretical models were found to provide reasonable accuracy of the prediction of ionization potentials for mono- and polycyclic azacompounds. The root mean square errors of the methods are 0.19 and 0.20, respectively. While the mean absolute deviation for both methods is the same and equals to 0.15 eV . These theoretical models were applied to predict ionization potentials for compounds not evaluated experimentally. Influence of substitutes and a number of nitrogen atoms on value of ionization potential was analyzed. Methyl-, and phenyl- groups, and fused benzo cycle decrease ionization potentials of N -heterocycles. Increase of amount of nitrogen atoms in five-membered cycles leads to significant enlargement of ionization potentials.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"22 1","pages":"59-62"},"PeriodicalIF":0.0,"publicationDate":"2014-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67579872","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}
S. Okovytyy, Svitlana D. Kopteva, E. Voronkov, T. Sergeieva, K. Kapusta, L. Dmitrikova, J. Leszczynski
Theoretical investigations of the conformational properties and 1 H NMR chemical shifts for N -methyl-4-tolyl-1-(4-bromonaphthyl)amine and N -phenyl-1-(4-bromonaphthyl)amine are reported. The calculations were performed at the DFT level (PBE1PBE functional) using magnetically consistent 6-31G ## and STO ## -3G mag basis sets. Conformational properties of the amines were studied using potential energy surface scanning. Chemical shifts were calculated using the GIAO and CSGT methods and averaged in proportion to the population of the corresponding conformations. Solvent effects (CDCl 3 ) were accounted via PCM method. The obtained results allowed to assign the 1 H NMR signals for the naphthalene moiety, which could not be done based on the experimental data alone.
{"title":"1H NMR spectra of N-methyl-4-tolyl-1-(4-bromonaphthyl)amine and N-phenyl-1-(4-bromonaphthyl)amine: a combined experimental and theoretical study","authors":"S. Okovytyy, Svitlana D. Kopteva, E. Voronkov, T. Sergeieva, K. Kapusta, L. Dmitrikova, J. Leszczynski","doi":"10.15421/081313","DOIUrl":"https://doi.org/10.15421/081313","url":null,"abstract":"Theoretical investigations of the conformational properties and 1 H NMR chemical shifts for N -methyl-4-tolyl-1-(4-bromonaphthyl)amine and N -phenyl-1-(4-bromonaphthyl)amine are reported. The calculations were performed at the DFT level (PBE1PBE functional) using magnetically consistent 6-31G ## and STO ## -3G mag basis sets. Conformational properties of the amines were studied using potential energy surface scanning. Chemical shifts were calculated using the GIAO and CSGT methods and averaged in proportion to the population of the corresponding conformations. Solvent effects (CDCl 3 ) were accounted via PCM method. The obtained results allowed to assign the 1 H NMR signals for the naphthalene moiety, which could not be done based on the experimental data alone.","PeriodicalId":31165,"journal":{"name":"Visnik Dnipropetrovs''kogo Universitetu Seria Himia","volume":"43 1","pages":"7-15"},"PeriodicalIF":0.0,"publicationDate":"2014-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67579405","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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