Pub Date : 2023-01-01DOI: 10.31489/2959-0663/2-23-8
N. Merkhatuly, Amantai N. Iskanderov, Saltanat B. Abeuova, Ablaykhan N. Iskanderov
Nowadays, non-benzenoid aromatic hydrocarbons are widely used as synthons for the production of new or-ganic semiconductors with interesting photophysical characteristics. For instance, a non-benzoid azulene hy-drocarbon with a polar structure, a narrow energy gap between the highest free and lowest occupied molecu-lar orbital and the ability to form stable ions can be intended as a structural moiety for the synthesis of new conjugated compounds with important optical and electronic properties. The article discusses the synthesis and investigation of the optical properties of new push-pull azulene-based compounds. It shows that Friedel-Crafts acylation is used as the key reaction for the synthesis of methyl- and phenyl-dicyanovinylated azulenes. The interaction proceeds regioselectively at the C1 and C3 positions of the five-membered azulene ring. It is identified that the synthesis of push-pull dicyanovinylated azulenes by Knoevenagel condensation of azulenyl ketones with malononitrile proceeds easily in Py and DMSO. The UF-vis spectra of the obtained azulene push-pull compounds demonstrated strong electron absorption in the visible zone with λmax at 410, 430, 434 and 452 nm associated with transport of charge between the donor azulene ring and the acceptor dicyanovinyl group. The scheme of resonant structures shows the mechanism of intramolecular donor-acceptor interaction. The structure of the synthesized push-pull dicyanovinylated nonazulenes was elucidated using modern physicochemical and spectroscopic research methods.
{"title":"Synthesis of Push-Pull Azulene-Based Compounds","authors":"N. Merkhatuly, Amantai N. Iskanderov, Saltanat B. Abeuova, Ablaykhan N. Iskanderov","doi":"10.31489/2959-0663/2-23-8","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-8","url":null,"abstract":"Nowadays, non-benzenoid aromatic hydrocarbons are widely used as synthons for the production of new or-ganic semiconductors with interesting photophysical characteristics. For instance, a non-benzoid azulene hy-drocarbon with a polar structure, a narrow energy gap between the highest free and lowest occupied molecu-lar orbital and the ability to form stable ions can be intended as a structural moiety for the synthesis of new conjugated compounds with important optical and electronic properties. The article discusses the synthesis and investigation of the optical properties of new push-pull azulene-based compounds. It shows that Friedel-Crafts acylation is used as the key reaction for the synthesis of methyl- and phenyl-dicyanovinylated azulenes. The interaction proceeds regioselectively at the C1 and C3 positions of the five-membered azulene ring. It is identified that the synthesis of push-pull dicyanovinylated azulenes by Knoevenagel condensation of azulenyl ketones with malononitrile proceeds easily in Py and DMSO. The UF-vis spectra of the obtained azulene push-pull compounds demonstrated strong electron absorption in the visible zone with λmax at 410, 430, 434 and 452 nm associated with transport of charge between the donor azulene ring and the acceptor dicyanovinyl group. The scheme of resonant structures shows the mechanism of intramolecular donor-acceptor interaction. The structure of the synthesized push-pull dicyanovinylated nonazulenes was elucidated using modern physicochemical and spectroscopic research methods.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79958664","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 : 2023-01-01DOI: 10.31489/2959-0663/1-23-5
L. Rakhymbay, Bagdaulet Shugay, Maksat Karlykan, Alibi Namazbay, Aishuak Konarov, Z. Bakenov
There has been an increasing amount of attention paid to the different technologies that are used in energy production and storage in the context of day-to-day operations, which range from small-scale applications to large-scale applications, which are all equally important. As far as energy storage systems are concerned, Li-ion batteries are the market leader due to their high energy and power density, making them one of the most popular choices. Despite this, a significant concern is the scarcity of lithium resources and other metals that are needed for cathode material, such as cobalt and nickel, in the long run. Recent research has focused on al-ternative energy storage systems to mitigate these concerns. Due to sodium's widespread availability and sim-ilar chemistry to lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) are considered the most promising next-generation alternatives. Being competitive in the market today requires the development of cathode ma-terials that are of high performance. Among the studied materials, the Na2Mn3O7 electrode displayed high ca-pacity. In addition, the low price of sodium and manganese makes it even more attractive. In this work, we summarized the recent progress in studying and enhancing the Na2Mn3O7 cathode material.
{"title":"Recent Advances in Layered Na2Mn3O7 Cathode Materials for Sodium-Ion Batteries","authors":"L. Rakhymbay, Bagdaulet Shugay, Maksat Karlykan, Alibi Namazbay, Aishuak Konarov, Z. Bakenov","doi":"10.31489/2959-0663/1-23-5","DOIUrl":"https://doi.org/10.31489/2959-0663/1-23-5","url":null,"abstract":"There has been an increasing amount of attention paid to the different technologies that are used in energy production and storage in the context of day-to-day operations, which range from small-scale applications to large-scale applications, which are all equally important. As far as energy storage systems are concerned, Li-ion batteries are the market leader due to their high energy and power density, making them one of the most popular choices. Despite this, a significant concern is the scarcity of lithium resources and other metals that are needed for cathode material, such as cobalt and nickel, in the long run. Recent research has focused on al-ternative energy storage systems to mitigate these concerns. Due to sodium's widespread availability and sim-ilar chemistry to lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) are considered the most promising next-generation alternatives. Being competitive in the market today requires the development of cathode ma-terials that are of high performance. Among the studied materials, the Na2Mn3O7 electrode displayed high ca-pacity. In addition, the low price of sodium and manganese makes it even more attractive. In this work, we summarized the recent progress in studying and enhancing the Na2Mn3O7 cathode material.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86948288","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 : 2023-01-01DOI: 10.31489/2959-0663/2-23-5
A. B. Yeszhanov, I. Korolkov, A. K. Shakayeva, Lana I. Lissovskaya, M. Zdorovets
Rapid industrial growth in the petrochemical, pharmaceutical, metallurgical and food industries, as well as stormwater that accumulates pollution from the roadway and the territories of motor transport enterprises, gas stations, car washes and other municipal services have led to the formation of a large amount of oily wastewater. Oil-containing wastewater is a multicomponent, multiphase water system and, as a rule, is in a state stabilized by various factors, which greatly complicates their processing. Pollution of water sources with oil-containing compounds leads to negative consequences for both living organisms and human health. Therefore, the need to treat oily wastewater is an urgent problem. In this article, poly(ethylene terephthalate) track-etched membranes (PET TeMs) with pore diameters of ~ 5.1 μm and pore density of 1∙106 pore/cm2 were modified by formation of polyelectrolyte complexes of PET TeMs surface with poly(allylamine) (PAAm) and tested for oil-water separation by using hexadecane/water (at pH=2) and chloroform/water (at pH=2) emulsions. Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), en-ergy dispersive X-ray (EDX) analysis, contact angle measurements were used for membrane characterization. The efficiency of oil-water separation was evaluated by flux measurements. Results showed separation per-formance of 267 mL/m2·s for hexadecane/water (pH=2) and 100 mL/m2·s for chloroform/water (pH=2) at vacuum pressure of 700 mbar.
{"title":"Preparation of Poly(Ethylene Terephthalate) Track-Etched Membranes for the Separation of Water-Oil Emulsions","authors":"A. B. Yeszhanov, I. Korolkov, A. K. Shakayeva, Lana I. Lissovskaya, M. Zdorovets","doi":"10.31489/2959-0663/2-23-5","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-5","url":null,"abstract":"Rapid industrial growth in the petrochemical, pharmaceutical, metallurgical and food industries, as well as stormwater that accumulates pollution from the roadway and the territories of motor transport enterprises, gas stations, car washes and other municipal services have led to the formation of a large amount of oily wastewater. Oil-containing wastewater is a multicomponent, multiphase water system and, as a rule, is in a state stabilized by various factors, which greatly complicates their processing. Pollution of water sources with oil-containing compounds leads to negative consequences for both living organisms and human health. Therefore, the need to treat oily wastewater is an urgent problem. In this article, poly(ethylene terephthalate) track-etched membranes (PET TeMs) with pore diameters of ~ 5.1 μm and pore density of 1∙106 pore/cm2 were modified by formation of polyelectrolyte complexes of PET TeMs surface with poly(allylamine) (PAAm) and tested for oil-water separation by using hexadecane/water (at pH=2) and chloroform/water (at pH=2) emulsions. Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), en-ergy dispersive X-ray (EDX) analysis, contact angle measurements were used for membrane characterization. The efficiency of oil-water separation was evaluated by flux measurements. Results showed separation per-formance of 267 mL/m2·s for hexadecane/water (pH=2) and 100 mL/m2·s for chloroform/water (pH=2) at vacuum pressure of 700 mbar.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91384024","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 : 2023-01-01DOI: 10.31489/2959-0663/2-23-4
A. Toibek, K. Rustembekov, Vitaly N. Fomin, D. Kaikenov
We synthesized samarium oxotellurites SmMTeO4.5 (M — Mg, Ba) by the method of ceramic technology with solid-phase interaction (800–1200 °С) of Sm2O3 and TeO2 oxides with MgCO3 and BaCO3 carbonates. The compounds were characterized by X-ray and electrophysics methods. It has been established that the syn-thesized compounds crystallize in the tetragonal syngony with the following crystallographic characteristics: SmMgTeO4.5 — a = 12.226; c = 5.783 Å, V0un.cell = 864.38 Å3, Z = 4, ρxray. = 2.876, ρpycn. = (2.874±0.002) g∙cm-3; SmBaTeO4.5 — a = 12.717; с = 6.132Å, V0un.cell = 991.62Å3, Z = 4, ρxray. = 3.264, ρpycn. = (3.260±0.004) g∙cm-3; for both tellurites α = β = γ = 90°. The experimental and calculated values of 2 Th and d-sp, X-ray and pycnometric densities, as well as theoretical and experimental values of unit cell volumes are agreed satisfac-torily. Thus, we can confirm correctness and reliability of the results of indexing X-ray patterns of new sa-marium oxotellurites. We found that increase in the ionic radii from Mg to Ba increases the lattice parameters of the synthesized oxotellurites. Oxotellurites are crystallized in the structural types of distorted perovskite Pm3m. Based on the given study samarium oxotellurites can have semiconductor and ferroelectric properties.
{"title":"New Samarium Oxotellurites: Synthesis and Characteristic","authors":"A. Toibek, K. Rustembekov, Vitaly N. Fomin, D. Kaikenov","doi":"10.31489/2959-0663/2-23-4","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-4","url":null,"abstract":"We synthesized samarium oxotellurites SmMTeO4.5 (M — Mg, Ba) by the method of ceramic technology with solid-phase interaction (800–1200 °С) of Sm2O3 and TeO2 oxides with MgCO3 and BaCO3 carbonates. The compounds were characterized by X-ray and electrophysics methods. It has been established that the syn-thesized compounds crystallize in the tetragonal syngony with the following crystallographic characteristics: SmMgTeO4.5 — a = 12.226; c = 5.783 Å, V0un.cell = 864.38 Å3, Z = 4, ρxray. = 2.876, ρpycn. = (2.874±0.002) g∙cm-3; SmBaTeO4.5 — a = 12.717; с = 6.132Å, V0un.cell = 991.62Å3, Z = 4, ρxray. = 3.264, ρpycn. = (3.260±0.004) g∙cm-3; for both tellurites α = β = γ = 90°. The experimental and calculated values of 2 Th and d-sp, X-ray and pycnometric densities, as well as theoretical and experimental values of unit cell volumes are agreed satisfac-torily. Thus, we can confirm correctness and reliability of the results of indexing X-ray patterns of new sa-marium oxotellurites. We found that increase in the ionic radii from Mg to Ba increases the lattice parameters of the synthesized oxotellurites. Oxotellurites are crystallized in the structural types of distorted perovskite Pm3m. Based on the given study samarium oxotellurites can have semiconductor and ferroelectric properties.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78490075","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 : 2023-01-01DOI: 10.31489/2959-0663/2-23-6
Ulygbek B. Tuleuov, A. Kazhmuratova, Abylaihan N. Bolatbay, Ermaut Nassikhatuly, Aizhan R. Koishugulova
The thermal properties of a copolymer based on polyethylene glycol fumarate with methacrylic acid in a ni-trogen atmosphere were studied in this paper. Four various heating rates and two types of a polyester resin composition were used. The analysis of thermal decomposition kinetics was implemented. Three kinetics methods namely Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose and Friedman were applied. Curves of a thermogravimetric analysis demonstrated that the thermal decomposition of copolymers with different molar ratios was observed. It was determined that the kinetic data depends on the studied copolymers’ composition. The obtained data showed a good convergence in various heating rates. Also, the thermodynamic characteris-tics were calculated namely the changes in the Gibbs energy (ΔG), enthalpy (ΔH) and entropy of activation (ΔS). The Achar-Brindley-Sharp method was used to find the invariant kinetic parameters of decomposition. Thus, the the kinetic compensation effect was applied to define a reaction model and a pre-exponential factor. A main phase of the copolymer decomposition in a narrow temperature range was determined. It was attested by a peak on the differential curve. An insignificant mass loss of the volatile-matter yield was observed in the range of 30–150 °C.
{"title":"Comparative Analysis of Thermal Decomposition Kinetics of Copolymers Based on Polyethylene Glycol Fumarate with Methacrylic Acid","authors":"Ulygbek B. Tuleuov, A. Kazhmuratova, Abylaihan N. Bolatbay, Ermaut Nassikhatuly, Aizhan R. Koishugulova","doi":"10.31489/2959-0663/2-23-6","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-6","url":null,"abstract":"The thermal properties of a copolymer based on polyethylene glycol fumarate with methacrylic acid in a ni-trogen atmosphere were studied in this paper. Four various heating rates and two types of a polyester resin composition were used. The analysis of thermal decomposition kinetics was implemented. Three kinetics methods namely Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose and Friedman were applied. Curves of a thermogravimetric analysis demonstrated that the thermal decomposition of copolymers with different molar ratios was observed. It was determined that the kinetic data depends on the studied copolymers’ composition. The obtained data showed a good convergence in various heating rates. Also, the thermodynamic characteris-tics were calculated namely the changes in the Gibbs energy (ΔG), enthalpy (ΔH) and entropy of activation (ΔS). The Achar-Brindley-Sharp method was used to find the invariant kinetic parameters of decomposition. Thus, the the kinetic compensation effect was applied to define a reaction model and a pre-exponential factor. A main phase of the copolymer decomposition in a narrow temperature range was determined. It was attested by a peak on the differential curve. An insignificant mass loss of the volatile-matter yield was observed in the range of 30–150 °C.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85101507","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 : 2023-01-01DOI: 10.31489/2959-0663/3-23-3
M. S. Zhukovsky, O. Maslova
The article highlights the creative path of S.A. Beznosyuk, an outstanding physico-chemist, who celebrates his 70th anniversary in 2023. The main stages of his career and significant events of his scientific creativity are presented here. The contribution of Professor S.A. Beznosyuk to the establishment and development of two scientific schools, namely quantum field chemistry of the condensed state at the Karaganda Buketov University and subatomic quantum nanotechnology of materials at Altai State University is show.
{"title":"S.A. Beznosyuk as the Founder and Leader of a New Direction of Quantum Field Chemistry in Subatomic Quantum Nanotechnologies of Materials","authors":"M. S. Zhukovsky, O. Maslova","doi":"10.31489/2959-0663/3-23-3","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-3","url":null,"abstract":"The article highlights the creative path of S.A. Beznosyuk, an outstanding physico-chemist, who celebrates his 70th anniversary in 2023. The main stages of his career and significant events of his scientific creativity are presented here. The contribution of Professor S.A. Beznosyuk to the establishment and development of two scientific schools, namely quantum field chemistry of the condensed state at the Karaganda Buketov University and subatomic quantum nanotechnology of materials at Altai State University is show.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89958647","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 : 2023-01-01DOI: 10.31489/2959-0663/2-23-11
G. Burkeyeva, A. Kovaleva, Y. Tazhbayev, Zhansaya M. Ibrayeva, L. Zhaparova, Diyara R. Meiramova, J. Plocek
This work is devoted to the investigation of continuous exposure to UV-irradiation on thermal stability of polymeric base of sealants. The copolymers of polyethylene glycol fumarate with acrylic and methacrylic ac-ids, and acrylamide of the composition of “unsaturated polyester : vinyl monomer” ~35:65 mass.% (corre-spondingly) were chosen as the polymer base. The samples were analyzed on microscope to the presence of microcracks as a result of exposure to UV-irradiation on them. The studied samples were evaluated visually on color change and the appearance of turbidity. Thermal stability of the studied polymeric base was deter-mined by establishing the temperature of the start of thermal deformation by thermogravimetry before and af-ter the process of UV-irradiation within 21 days. It was established that for the polymeric base with acryla-mide in its content the temperature of the start of thermal deformation had reduced after exposure to UV-irradiation. In contrary, for the polymeric bases with acrylic and methacrylic acids in their composition the abovesaid thermal index almost had not changed after affecting with UV-irradiation on the samples.
{"title":"Investigation of the Influence of UV-Irradiation on Thermal Stability of Binary Systems on the Basis of Polyethylene Glycol Fumarate with Some Vinyl Monomers","authors":"G. Burkeyeva, A. Kovaleva, Y. Tazhbayev, Zhansaya M. Ibrayeva, L. Zhaparova, Diyara R. Meiramova, J. Plocek","doi":"10.31489/2959-0663/2-23-11","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-11","url":null,"abstract":"This work is devoted to the investigation of continuous exposure to UV-irradiation on thermal stability of polymeric base of sealants. The copolymers of polyethylene glycol fumarate with acrylic and methacrylic ac-ids, and acrylamide of the composition of “unsaturated polyester : vinyl monomer” ~35:65 mass.% (corre-spondingly) were chosen as the polymer base. The samples were analyzed on microscope to the presence of microcracks as a result of exposure to UV-irradiation on them. The studied samples were evaluated visually on color change and the appearance of turbidity. Thermal stability of the studied polymeric base was deter-mined by establishing the temperature of the start of thermal deformation by thermogravimetry before and af-ter the process of UV-irradiation within 21 days. It was established that for the polymeric base with acryla-mide in its content the temperature of the start of thermal deformation had reduced after exposure to UV-irradiation. In contrary, for the polymeric bases with acrylic and methacrylic acids in their composition the abovesaid thermal index almost had not changed after affecting with UV-irradiation on the samples.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84168275","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 : 2023-01-01DOI: 10.31489/2959-0663/1-23-12
A. Sarsenbekova, M. Burkeyev, G. M. Zhumanazarova, G. Kudaibergen, Yermauyt Nasikhatuly
The article is devoted to the study of the influence of external factors on copolymers based on poly(propylene fumarate phthalate) with acrylic acid. In the present work, the effect of low-molecular salts on the swelling rate of the synthesized copolymers was studied. The surface morphology was examined using SEM. The swelling rate of the studied polymers depends on many factors, including the nature of the polymer and the solvent, the presence of electrolytes, changes in pH and ambient temperature, the molecular weight of the polymer, etc. It is assumed that the polymer network of copolymers mainly consists of links of unsaturated polyester resin. The results show that the ratio of monomer units in the copolymer significantly affects the susceptibility of the polymer gel to the presence of low-molecular salts. Changing the properties of the comonomer has been shown to produce hydrogels that can swell or collapse due to changes in ionic strength or the thermodynamic quality of the solution. By varying the ratio of the comonomeric units, the intervals of swelling and contraction of polymer meshes inherent in polyelectrolyte bodies with the same charges were adjusted. It was also found that the polymers under consideration belong to anionic meshes.
{"title":"The Effect of Liquid Active Media on the Character of Equilibrium Swelling of Copolymers Based on Polypropylene Fumarate Phthalate with Acrylic Acid","authors":"A. Sarsenbekova, M. Burkeyev, G. M. Zhumanazarova, G. Kudaibergen, Yermauyt Nasikhatuly","doi":"10.31489/2959-0663/1-23-12","DOIUrl":"https://doi.org/10.31489/2959-0663/1-23-12","url":null,"abstract":"The article is devoted to the study of the influence of external factors on copolymers based on poly(propylene fumarate phthalate) with acrylic acid. In the present work, the effect of low-molecular salts on the swelling rate of the synthesized copolymers was studied. The surface morphology was examined using SEM. The swelling rate of the studied polymers depends on many factors, including the nature of the polymer and the solvent, the presence of electrolytes, changes in pH and ambient temperature, the molecular weight of the polymer, etc. It is assumed that the polymer network of copolymers mainly consists of links of unsaturated polyester resin. The results show that the ratio of monomer units in the copolymer significantly affects the susceptibility of the polymer gel to the presence of low-molecular salts. Changing the properties of the comonomer has been shown to produce hydrogels that can swell or collapse due to changes in ionic strength or the thermodynamic quality of the solution. By varying the ratio of the comonomeric units, the intervals of swelling and contraction of polymer meshes inherent in polyelectrolyte bodies with the same charges were adjusted. It was also found that the polymers under consideration belong to anionic meshes.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78821978","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 : 2023-01-01DOI: 10.31489/2959-0663/3-23-4
A. Ryabykh, O. Maslova, S. Beznosyuk
In this paper, we propose an approach to resolving some questions about the catalytic action of manganese and iron superoxide dismutases. At the level of a pure quantum-chemical calculation using an ORCA 5.0.3 program, a PBE functional and a def2-SVP and def2-TZVP basis sets, the possible mechanisms of superoxide ions binding to the active sites of enzymes, the electron transfer distances and their characteristics were estab-lished. It is shown that the initial form of the fifth ligand in both active centers is the hydroxide ion OH–. Be-fore the primary electron transfer, active sites are protonated, the hydroxide ion is converted into a water mol-ecule H2O. Primary electron transfers from the superoxide ion to Mn3+-SOD and Fe3+-SOD occur by the as-sociative mechanism, with the formation of an octahedral complex, at a transfer distance of 1.95 Å and 2.56 Å, respectively. At the second stage, the superoxide ion accepts the electron by the substitution mecha-nism from Mn2+-SOD at the transfer distance of 2 Å to form bonds with the water molecule and a tyrosine. The superoxide ion accepts the electron from Fe2+-SOD through the outer-sphere mechanism, where it binds to a histidine and the water molecule at the transfer distance of 4.24 Å.
{"title":"Mechanisms of Docking of Superoxide Ions in the Catalytic Cycle of Manganese and Iron Superoxide Dismutases","authors":"A. Ryabykh, O. Maslova, S. Beznosyuk","doi":"10.31489/2959-0663/3-23-4","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-4","url":null,"abstract":"In this paper, we propose an approach to resolving some questions about the catalytic action of manganese and iron superoxide dismutases. At the level of a pure quantum-chemical calculation using an ORCA 5.0.3 program, a PBE functional and a def2-SVP and def2-TZVP basis sets, the possible mechanisms of superoxide ions binding to the active sites of enzymes, the electron transfer distances and their characteristics were estab-lished. It is shown that the initial form of the fifth ligand in both active centers is the hydroxide ion OH–. Be-fore the primary electron transfer, active sites are protonated, the hydroxide ion is converted into a water mol-ecule H2O. Primary electron transfers from the superoxide ion to Mn3+-SOD and Fe3+-SOD occur by the as-sociative mechanism, with the formation of an octahedral complex, at a transfer distance of 1.95 Å and 2.56 Å, respectively. At the second stage, the superoxide ion accepts the electron by the substitution mecha-nism from Mn2+-SOD at the transfer distance of 2 Å to form bonds with the water molecule and a tyrosine. The superoxide ion accepts the electron from Fe2+-SOD through the outer-sphere mechanism, where it binds to a histidine and the water molecule at the transfer distance of 4.24 Å.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79327096","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 : 2023-01-01DOI: 10.31489/2959-0663/2-23-1
O. Nurkenov, S. Fazylov, T. Seilkhanov, L. Abulyaissova, K. M. Turdybekov, T. Zhivotova, S. Kabieva, A. Mendibayeva
There has been presented data on the synthesis of monoamides and cyclic imides which are derivatives of isonicotinic acid hydrazide. Cyclic anhydrides of carboxylic acids (succinic, maleic and phthalic) easily react with the hydrazide of isonicotinic acid with cycle opening, forming isonicotinoylhydrazide of dicarboxylic acids, and under more severe conditions the latter are transformed into cyclic acid imides. The structures of the synthesized compounds were studied using 1H- and 13C-NMR spectroscopy, as well as data from twodimensional COSY (1H-1H) and HMQC (1H-13C) spectra. The values of chemical shifts, multiplicity and integral intensity of 1H and 13C signals in one-dimensional NMR spectra were determined. Homo- and heteronuclear interactions confirming the structure of the studied compounds were established using spectra in the COSY (1H-1H) and HMQC (1H-13C) formats. In the approximation of the density functional B3LYP with a base set of 6-31G(d), the enthalpy of the reactions ΔHr in the absence and in the presence of a solvent — isopropanol (self-consistent reaction field method) were calculated quantum-chemically.
{"title":"Interaction of Isonicotinic Acid Hydrazide with Carboxylic Acid Anhydrides","authors":"O. Nurkenov, S. Fazylov, T. Seilkhanov, L. Abulyaissova, K. M. Turdybekov, T. Zhivotova, S. Kabieva, A. Mendibayeva","doi":"10.31489/2959-0663/2-23-1","DOIUrl":"https://doi.org/10.31489/2959-0663/2-23-1","url":null,"abstract":"There has been presented data on the synthesis of monoamides and cyclic imides which are derivatives of isonicotinic acid hydrazide. Cyclic anhydrides of carboxylic acids (succinic, maleic and phthalic) easily react with the hydrazide of isonicotinic acid with cycle opening, forming isonicotinoylhydrazide of dicarboxylic acids, and under more severe conditions the latter are transformed into cyclic acid imides. The structures of the synthesized compounds were studied using 1H- and 13C-NMR spectroscopy, as well as data from twodimensional COSY (1H-1H) and HMQC (1H-13C) spectra. The values of chemical shifts, multiplicity and integral intensity of 1H and 13C signals in one-dimensional NMR spectra were determined. Homo- and heteronuclear interactions confirming the structure of the studied compounds were established using spectra in the COSY (1H-1H) and HMQC (1H-13C) formats. In the approximation of the density functional B3LYP with a base set of 6-31G(d), the enthalpy of the reactions ΔHr in the absence and in the presence of a solvent — isopropanol (self-consistent reaction field method) were calculated quantum-chemically.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82771255","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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