Pub Date : 2023-01-16DOI: 10.13171/mjc02301161661elmehdawi
R. M. Elmehdawi
The new cobalt (II) complex, [Co12 (cpip)12(H2O)12].18.56H2O where H2cpip = 2-(carboxy-phenyl) amino-propanoic acid, was isolated as pink-like prism crystals from the reaction of Co(NO3)2.6H2O and H2cpip in an ethanolic solution. The complex was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and X-ray single-crystal diffraction. The symmetric unit of the title complex contains twelve cobalt atoms arranged in a cube-octahedron. Each divalent cation of cobalt is iso-octahedrally coordinated to four oxygen atoms of two cpip2- ligands in the equatorial plane. The axial plane is occupied by an amino nitrogen atom of one of the cpip2- ligands and an oxygen atom of a water molecule. The lattice water molecule in the metallocycle cavity involved OHO hydrogen bonding with the coordinated water molecules.
{"title":"Synthesis, characterization and crystal structure of a dodeca-nuclear cobalt (II)cube-octahedron","authors":"R. M. Elmehdawi","doi":"10.13171/mjc02301161661elmehdawi","DOIUrl":"https://doi.org/10.13171/mjc02301161661elmehdawi","url":null,"abstract":"<p>The new cobalt (II) complex, [Co<sub>12 </sub>(cpip)<sub>12</sub>(H<sub>2</sub>O)<sub>12</sub>].18.56H<sub>2</sub>O where H<sub>2</sub>cpip = 2-(carboxy-phenyl) amino-propanoic acid, was isolated as pink-like prism crystals from the reaction of Co(NO<sub>3</sub>)<sub>2</sub>.6H<sub>2</sub>O and H<sub>2</sub>cpip in an ethanolic solution. The complex was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and X-ray single-crystal diffraction. The symmetric unit of the title complex contains twelve cobalt atoms arranged in a cube-octahedron. Each divalent cation of cobalt is iso-octahedrally coordinated to four oxygen atoms of two cpip2- ligands in the equatorial plane. The axial plane is occupied by an amino nitrogen atom of one of the cpip2- ligands and an oxygen atom of a water molecule. The lattice water molecule in the metallocycle cavity involved OHO hydrogen bonding with the coordinated water molecules.</p>","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85441985","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 : 2023-01-13DOI: 10.13171/mjc02301131663rohin
Nurul Fatihah Muhamad Pithonah, Mohd Adzim Khalili Rohin, Nor Aishah Fatiha Jailani, N. Ridzwan, Mimie Noratiqah Jumli, Norhayati Abd Hadi, Ruziana Ishak, Atif Amin Baig
Lansium parasiticum (Osbeck) or its synonym Epicharis parasitica is from the Meliaceae family and has traditionally been used for various medical applications. This study aimed to determine the total phenolic content, total flavonoid content, and antioxidant activity of different duku extracts. A total of four different solvents, 50% ethanol, 100% aqueous, 100% acetone, and 100% chloroform, were used to extract duku flesh. The total phenolic and flavonoid content was determined using the Folin-Ciocaltealuminumminium chloride colorimetric method. The DPPH and ABTS method evaluated the antioxidant activity. The result showed that 50% ethanol presented the highest extraction yield, 10.81% ± 0.004. It is also revealed that aqueous extract exhibited the highest amount of total phenolic content of 152.910 mg GAE/100 g ± 22.143, total flavonoid content of 1669.723 ± 370.091 mg QE/100 g, and antioxidant activity DPPH of 68.51 % ± 2.730 and ABTS of 6.063 U/ml ± 0.721 compared to other extracts. The correlation between total phenolic content and ABTS (r = 0.719, p = 0.029) showed a statistically significant result. Therefore, the extracts of this fruit have promising potential as cheap sources of future natural antioxidant agents in the food industry. Researchers will further these results for future in-vitro or in-vivo biological studies.
{"title":"Study on phenolic content, flavonoid content, and antioxidant capacity of extracts from Lansium parasiticum (Osbeck)","authors":"Nurul Fatihah Muhamad Pithonah, Mohd Adzim Khalili Rohin, Nor Aishah Fatiha Jailani, N. Ridzwan, Mimie Noratiqah Jumli, Norhayati Abd Hadi, Ruziana Ishak, Atif Amin Baig","doi":"10.13171/mjc02301131663rohin","DOIUrl":"https://doi.org/10.13171/mjc02301131663rohin","url":null,"abstract":"Lansium parasiticum (Osbeck) or its synonym Epicharis parasitica is from the Meliaceae family and has traditionally been used for various medical applications. This study aimed to determine the total phenolic content, total flavonoid content, and antioxidant activity of different duku extracts. A total of four different solvents, 50% ethanol, 100% aqueous, 100% acetone, and 100% chloroform, were used to extract duku flesh. The total phenolic and flavonoid content was determined using the Folin-Ciocaltealuminumminium chloride colorimetric method. The DPPH and ABTS method evaluated the antioxidant activity. The result showed that 50% ethanol presented the highest extraction yield, 10.81% ± 0.004. It is also revealed that aqueous extract exhibited the highest amount of total phenolic content of 152.910 mg GAE/100 g ± 22.143, total flavonoid content of 1669.723 ± 370.091 mg QE/100 g, and antioxidant activity DPPH of 68.51 % ± 2.730 and ABTS of 6.063 U/ml ± 0.721 compared to other extracts. The correlation between total phenolic content and ABTS (r = 0.719, p = 0.029) showed a statistically significant result. Therefore, the extracts of this fruit have promising potential as cheap sources of future natural antioxidant agents in the food industry. Researchers will further these results for future in-vitro or in-vivo biological studies.","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78316531","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 : 2023-01-05DOI: 10.13171/mjc02301051658mezni
F. Mezni, A. Slama, Faten Ayari, Khaoula Smirani, A. Khaldi
This study aims to determine the effect of fruit storage conditions on the yield and quality of Pistacia lentiscus oil. Fruits were harvested in North Tunisia, and oil was extracted using the pressing method. Three storage conditions were tested; fruit is frozen at -20°C, fruit storage in a cold room at 4°C, and air-dried fruits at 25°C. Oil yield, free fatty acids, peroxide value, and total polyphenolic content were determined after 30, 60, and 90 days of storage. During the first 30 days, the highest yield was reached by fruits stored in a cold room (15%). Oil acidity from freshly harvested lentisk fruits was around 6% and then increased during storage. With increasing storage time, the oil peroxide value and the total polyphenolic content decreased in the fruits from all treatments. The peroxide value reached the respective values of 8, 5, and 23 meq O2/kg oil for Frozen, Cold Room, and Air Drying treatments. The total polyphenolic content varied from 0.5 EGA/g oil for air drying and frozen treatments to 0.8 EGA/g oil for the cold room. This study allowed the determination of the optimal conditions of storage of Pistacia lentiscus oil. These results are important to preserve the oil's quality and chemical and medicinal properties.
{"title":"Effect of fruits storage conditions on the yield and the quality of Pistacia lentiscus oil","authors":"F. Mezni, A. Slama, Faten Ayari, Khaoula Smirani, A. Khaldi","doi":"10.13171/mjc02301051658mezni","DOIUrl":"https://doi.org/10.13171/mjc02301051658mezni","url":null,"abstract":"This study aims to determine the effect of fruit storage conditions on the yield and quality of Pistacia lentiscus oil. Fruits were harvested in North Tunisia, and oil was extracted using the pressing method. Three storage conditions were tested; fruit is frozen at -20°C, fruit storage in a cold room at 4°C, and air-dried fruits at 25°C. Oil yield, free fatty acids, peroxide value, and total polyphenolic content were determined after 30, 60, and 90 days of storage. During the first 30 days, the highest yield was reached by fruits stored in a cold room (15%). Oil acidity from freshly harvested lentisk fruits was around 6% and then increased during storage. With increasing storage time, the oil peroxide value and the total polyphenolic content decreased in the fruits from all treatments. The peroxide value reached the respective values of 8, 5, and 23 meq O2/kg oil for Frozen, Cold Room, and Air Drying treatments. The total polyphenolic content varied from 0.5 EGA/g oil for air drying and frozen treatments to 0.8 EGA/g oil for the cold room. This study allowed the determination of the optimal conditions of storage of Pistacia lentiscus oil. These results are important to preserve the oil's quality and chemical and medicinal properties.","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76430372","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 : 2023-01-04DOI: 10.13171/mjc02301041662diallo
Waly Diallo, Boucar Diouf, Bougar Sarr, Mouhamadou Sembéne Boye, Pechev Stanislav Pavlov, F. Michaud
The compound CyNH3[HOOC(CH)2COO]·H2O has been obtained using one pot-synthesis process by mixing, in methanol, HOOC(CH)2COOH, CyNH2 and SnPh3Cl in a 1:1:1 molar ratio. X-ray diffraction analysis of the compound reveals that in the crystal structure, hydrogen maleate [HOOC(CH)2COO]- in cis configuration interacts with [CyNH3]+ cations and water molecules to generate an R66(22) ring. The interconnections of the rings via simple (N–H··O and O–H··O) and bifurcated (N–H···(O, O)) hydrogen bonds give rise to a 2D supramolecular structure.
{"title":"Crystal structure of cyclohexylammonium hydrogen maleate salt hemi-hydrated","authors":"Waly Diallo, Boucar Diouf, Bougar Sarr, Mouhamadou Sembéne Boye, Pechev Stanislav Pavlov, F. Michaud","doi":"10.13171/mjc02301041662diallo","DOIUrl":"https://doi.org/10.13171/mjc02301041662diallo","url":null,"abstract":"<p>The compound CyNH<sub>3</sub>[HOOC(CH)<sub>2</sub>COO]·H<sub>2</sub>O has been obtained using one pot-synthesis process by mixing, in methanol, HOOC(CH)<sub>2</sub>COOH, CyNH<sub>2</sub> and SnPh<sub>3</sub>Cl in a 1:1:1 molar ratio. X-ray diffraction analysis of the compound reveals that in the crystal structure, hydrogen maleate [HOOC(CH)<sub>2</sub>COO]<sup>-</sup> in cis configuration interacts with [CyNH<sub>3</sub>]<sup>+</sup> cations and water molecules to generate an R<sub>6</sub><sup>6</sup>(22) ring. The interconnections of the rings via simple (N–H··O and O–H··O) and bifurcated (N–H···(O, O)) hydrogen bonds give rise to a 2D supramolecular structure.</p>","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91537864","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 : 2022-12-30DOI: 10.13171/mjc02212301652obibuenyi
I. J. Obibuenyi, O. Onukwuli, Luvia Uche Ezeamaku, Ochiagha I. Eze
Bamboo fibers are modified for improved interfacial bonding and reduction of moisture absorption. This is achievable through various treatments. The bamboo fiber's mechanical and chemical properties were examined with a Tensile machine and FTIR instrument. Natural fibers have many advantages over manufactured fibers like low density, low cost, biodegradability, poor compatibility between them and the matrix, relatively high moisture sorption, etc. The treatments are vital to modify the surface properties. For this, potassium permanganate (KMnO4) was used in this study. The Fourier transform Infra-red (FT-IR) analysis of untreated bamboo fiber showed the presence of the Hydrogen-bonded (O-H) stretch, H-C-H asymmetric and symmetric stretch, C-H stretch of C=O, C≡N stretch, N=O Bend, and C-O stretch. For the treated bamboo fiber, the analysis shows similar results. Similarly, results of reinforced bamboo fiber showed hydrogen-bonded O-H stretch, C-H stretch of C=O, C≡C stretch (C-O stretch), N=O stretch, and N-H bend. The treated Bamboo fiber was reinforced with a bio-resin (natural honey and pawpaw extract). Mechanical testing was done to get the tensile strength at increased concentration, and FT-IR was used to get the effects of chemical treatment on the fibers. Potassium permanganate treatment improved the properties with increased concentrations.
{"title":"Examining the effect of permanganate (KMnO4) on bamboo fiber (Bambusa vulgaris) reinforced with bio-resin natural honey (melitera) and pawpaw (Carica papaya) leaves extract","authors":"I. J. Obibuenyi, O. Onukwuli, Luvia Uche Ezeamaku, Ochiagha I. Eze","doi":"10.13171/mjc02212301652obibuenyi","DOIUrl":"https://doi.org/10.13171/mjc02212301652obibuenyi","url":null,"abstract":"Bamboo fibers are modified for improved interfacial bonding and reduction of moisture absorption. This is achievable through various treatments. The bamboo fiber's mechanical and chemical properties were examined with a Tensile machine and FTIR instrument. Natural fibers have many advantages over manufactured fibers like low density, low cost, biodegradability, poor compatibility between them and the matrix, relatively high moisture sorption, etc. The treatments are vital to modify the surface properties. For this, potassium permanganate (KMnO4) was used in this study. The Fourier transform Infra-red (FT-IR) analysis of untreated bamboo fiber showed the presence of the Hydrogen-bonded (O-H) stretch, H-C-H asymmetric and symmetric stretch, C-H stretch of C=O, C≡N stretch, N=O Bend, and C-O stretch. For the treated bamboo fiber, the analysis shows similar results. Similarly, results of reinforced bamboo fiber showed hydrogen-bonded O-H stretch, C-H stretch of C=O, C≡C stretch (C-O stretch), N=O stretch, and N-H bend. The treated Bamboo fiber was reinforced with a bio-resin (natural honey and pawpaw extract). Mechanical testing was done to get the tensile strength at increased concentration, and FT-IR was used to get the effects of chemical treatment on the fibers. Potassium permanganate treatment improved the properties with increased concentrations.","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81063885","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 : 2022-11-14DOI: 10.13171/mjc02211141647das
Aayushi Chanderiya, A. Roy, R. Das
This research describes a multi-component condensation reaction of 3,4-dihydropyrano[c]chromene from aldehydes, Dicyanomethane, and 4-Hydroxy-2H-chromen-2-one in a solvent system having water and ethanol at ambient temperature. The ratio of water and ethanol was 1:1. Mild reaction temperatures, quick reaction durations, facile product isolation, use of less hazardous solvents, and excellent yields are all essential and valuable characteristics of this approach. In addition, nanoparticles showed perfect catalytic activity since they have more surface area. The electrochemical study of the synthesized product has been done by cyclic voltammetry.
{"title":"Synthesis of 3,4-dihydropyrano[c]chromene derivatives using porous copper oxide as nanocatalyst and their electrochemical study","authors":"Aayushi Chanderiya, A. Roy, R. Das","doi":"10.13171/mjc02211141647das","DOIUrl":"https://doi.org/10.13171/mjc02211141647das","url":null,"abstract":"This research describes a multi-component condensation reaction of 3,4-dihydropyrano[c]chromene from aldehydes, Dicyanomethane, and 4-Hydroxy-2H-chromen-2-one in a solvent system having water and ethanol at ambient temperature. The ratio of water and ethanol was 1:1. Mild reaction temperatures, quick reaction durations, facile product isolation, use of less hazardous solvents, and excellent yields are all essential and valuable characteristics of this approach. In addition, nanoparticles showed perfect catalytic activity since they have more surface area. The electrochemical study of the synthesized product has been done by cyclic voltammetry.","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"272 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76429646","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 : 2022-11-02DOI: 10.13171/mjc02211021650csuk
Niels V. Heise, Jördis-Ann Schüler, Torje E. Orlamünde, Benjamin Brandes, H. Deigner, A. Al‐Harrasi, R. Csuk
: Parkinson's disease (PD) is the second most common neurodegenerative disease. Besides rigidity and tremor, patients often suffer from gait disturbance. Treatment with cholinesterase inhibitors (ChEI) has been shown to improve gait speed. Thus, the triterpene acids oleanolic acid and ursolic acid have been used as starting materials for the synthesis of compounds intended to act as inhibitors of the enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The parent compounds were acetylated and converted via isocyanates and amines into a series of amides, while the isocyanates were also used as starting materials for the synthesis of several urea derivatives. Screening of the compounds with the cholinesterases showed them to be good to moderate inhibitors, with ursolic acid derived isocyanate being a superior mixed-type dual inhibitor for both enzymes holding Ki values in the low mM concentration range. The data from the experiments parallel the results from molecular modeling calculations. In addition, this compound is remarkably stable in an aqueous solution and undergoes decarboxylative hydrolysis to the corresponding amine only at 50 °C after several hours.
{"title":"Triterpenoid cholinesterase inhibitors that might improve gait disturbances in Parkinson's disease patients","authors":"Niels V. Heise, Jördis-Ann Schüler, Torje E. Orlamünde, Benjamin Brandes, H. Deigner, A. Al‐Harrasi, R. Csuk","doi":"10.13171/mjc02211021650csuk","DOIUrl":"https://doi.org/10.13171/mjc02211021650csuk","url":null,"abstract":": Parkinson's disease (PD) is the second most common neurodegenerative disease. Besides rigidity and tremor, patients often suffer from gait disturbance. Treatment with cholinesterase inhibitors (ChEI) has been shown to improve gait speed. Thus, the triterpene acids oleanolic acid and ursolic acid have been used as starting materials for the synthesis of compounds intended to act as inhibitors of the enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The parent compounds were acetylated and converted via isocyanates and amines into a series of amides, while the isocyanates were also used as starting materials for the synthesis of several urea derivatives. Screening of the compounds with the cholinesterases showed them to be good to moderate inhibitors, with ursolic acid derived isocyanate being a superior mixed-type dual inhibitor for both enzymes holding Ki values in the low mM concentration range. The data from the experiments parallel the results from molecular modeling calculations. In addition, this compound is remarkably stable in an aqueous solution and undergoes decarboxylative hydrolysis to the corresponding amine only at 50 °C after several hours.","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"83 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77623639","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 : 2022-10-19DOI: 10.13171/mjc02210191648taghi
Tahmina Taghi, V. Baghiyev
The activities of binary zirconium-zinc oxide catalysts in the reaction of ethanol conversion to acetone were studied. It has been established that with an increase in the reaction temperature, the yields of acetone, carbon dioxide, and acetaldehyde pass through a maximum. In contrast, the yield of ethylene increases over the entire temperature range studied. It was found that the dependences of the acetone yield and the ethanol conversion on the atomic ratio of zirconium to zinc have the form of a curve with two maxima. A maximal yield of acetone 58.2% was observed over catalyst Zr-Zn=8-2 at a temperature of 500°C. The specific surfaces of zirconium-zinc oxide catalysts have been studied. It has been established that the specific surface area of zirconium-zinc oxide catalysts varies in the ra.8 m2/g. The effect of the surface on the yields of ethanol conversion products has been studied. It has been shown that with an increase in the specific surface area of zirconium-zinc oxide catalysts, the yield of acetone passes through a maximum. In contrast, the yields of acetaldehyde, carbon dioxide, and ethylene practically do not change.
{"title":"Effect of specific surface on the activities of binary Zr-Zn-O catalysts in the reaction of ethanol conversion","authors":"Tahmina Taghi, V. Baghiyev","doi":"10.13171/mjc02210191648taghi","DOIUrl":"https://doi.org/10.13171/mjc02210191648taghi","url":null,"abstract":"The activities of binary zirconium-zinc oxide catalysts in the reaction of ethanol conversion to acetone were studied. It has been established that with an increase in the reaction temperature, the yields of acetone, carbon dioxide, and acetaldehyde pass through a maximum. In contrast, the yield of ethylene increases over the entire temperature range studied. It was found that the dependences of the acetone yield and the ethanol conversion on the atomic ratio of zirconium to zinc have the form of a curve with two maxima. A maximal yield of acetone 58.2% was observed over catalyst Zr-Zn=8-2 at a temperature of 500°C. The specific surfaces of zirconium-zinc oxide catalysts have been studied. It has been established that the specific surface area of zirconium-zinc oxide catalysts varies in the ra.8 m2/g. The effect of the surface on the yields of ethanol conversion products has been studied. It has been shown that with an increase in the specific surface area of zirconium-zinc oxide catalysts, the yield of acetone passes through a maximum. In contrast, the yields of acetaldehyde, carbon dioxide, and ethylene practically do not change.","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83809963","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 : 2022-10-11DOI: 10.13171/mjc02210111645eteer
S. A. Eteer
Cyclodextrin molecules can form inclusion complexes with various compounds of appropriate shape and size. The complexation can enhance the solubility and stability of the inclusion guest compound. The stoichiometry and stability constant of the host-guest complex are highly important for physical, chemical, biological, and environmental studies. A simple and rapid spectroscopic method investigated the inclusion of vanillin and β-cyclodextrin (β-CD). The continuous variation technique was used to estimate the stoichiometry of the inclusion complex. The association constant of vanillin with β-CD was determined by using Benesi- Hildebrand and Scott's methods which were calculated to be 179 and 187 M-1, respectively, with the stoichiometry ratio, was 1:1 for the inclusion complex of β-CD with vanillin.
{"title":"UV-Vis Spectroscopic Characterization of β-Cyclodextrin-Vanillin Inclusion Complex","authors":"S. A. Eteer","doi":"10.13171/mjc02210111645eteer","DOIUrl":"https://doi.org/10.13171/mjc02210111645eteer","url":null,"abstract":"Cyclodextrin molecules can form inclusion complexes with various compounds of appropriate shape and size. The complexation can enhance the solubility and stability of the inclusion guest compound. The stoichiometry and stability constant of the host-guest complex are highly important for physical, chemical, biological, and environmental studies. A simple and rapid spectroscopic method investigated the inclusion of vanillin and β-cyclodextrin (β-CD). The continuous variation technique was used to estimate the stoichiometry of the inclusion complex. The association constant of vanillin with β-CD was determined by using Benesi- Hildebrand and Scott's methods which were calculated to be 179 and 187 M-1, respectively, with the stoichiometry ratio, was 1:1 for the inclusion complex of β-CD with vanillin.","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75489370","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 : 2022-10-07DOI: 10.13171/mjc02210071641kartoshkin
V. Kartoshkin
In the collision of spin-polarized atoms, the transmission of electron polarization between colliding particles is possible. A similar situation occurs in a collision, for example, between alkali atoms in the ground state. If one of the colliding particles is in an excited state and its energy is sufficient for ionization of the collision partner, then along with the elastic process (spin exchange), an inelastic process (ionization) is also possible, as a result of these processes polarization can also be transferred to the partner. Simultaneously occurring elastic and inelastic processes at the collision between two helium atoms are possible if these atoms are in the metastable (23S1) state. The paper discusses the interaction between spin-polarized metastable atoms of helium-3 and helium-4 isotopes under conditions of optical pumping of atoms. Complex interaction potentials of the atoms under consideration were constructed and on their basis, the spin exchange and chemo-ionization cross-sections were calculated. Using these cross-sections, expressions for the transfer of orientation and alignment from one atom to another were obtained.
{"title":"Angular Momentum Transfer at the Chemo-ionization and Spin Exchange Processes. Interaction between Spin Polarized Metastable Helium Atoms","authors":"V. Kartoshkin","doi":"10.13171/mjc02210071641kartoshkin","DOIUrl":"https://doi.org/10.13171/mjc02210071641kartoshkin","url":null,"abstract":"In the collision of spin-polarized atoms, the transmission of electron polarization between colliding particles is possible. A similar situation occurs in a collision, for example, between alkali atoms in the ground state. If one of the colliding particles is in an excited state and its energy is sufficient for ionization of the collision partner, then along with the elastic process (spin exchange), an inelastic process (ionization) is also possible, as a result of these processes polarization can also be transferred to the partner. Simultaneously occurring elastic and inelastic processes at the collision between two helium atoms are possible if these atoms are in the metastable (23S1) state. The paper discusses the interaction between spin-polarized metastable atoms of helium-3 and helium-4 isotopes under conditions of optical pumping of atoms. Complex interaction potentials of the atoms under consideration were constructed and on their basis, the spin exchange and chemo-ionization cross-sections were calculated. Using these cross-sections, expressions for the transfer of orientation and alignment from one atom to another were obtained.","PeriodicalId":18513,"journal":{"name":"Mediterranean Journal of Chemistry","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74249562","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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