Pub Date : 2021-01-01DOI: 10.1177/14686783211010966
Zheng Zou, Yangui Chen, Jieqing Zheng, Xiao-dong Zhang, Hongzhou He
The co-combustion characteristics of Fujian anthracite with two biomasses (i.e. Cunninghamia lanceolata) and Mycorrhizal plants in different proportions were investigated using thermogravimetric analysis. The result showed that first, the co-combustion processes of Fujian anthracite with the two biomasses (Cunninghamia lanceolata and Mycorrhizal plants) proceeded in three stages, separation and combustion of volatiles, combustion of fixed carbon in the biomass, and combustion of fixed carbon in Fujian anthracite. Secondly with increasing proportion of biomass, the co-combustion of Fujian anthracite with Cunninghamia lanceolata and Mycorrhizal plants shifted to a low-temperature zone, with a lower ignition temperature, shortened burnout time, and growth of both combustibility index (Ci) and comprehensive combustion index S. Finally, at different mixing proportions, the comprehensive combustion index S during co-combustion of FW with Mycorrhizal plants is always larger than that during co-combustion with Cunninghamia lanceolata; therefore, FW and Mycorrhizal plants exhibit superior comprehensive co-combustion performance to FW and Cunninghamia lanceolata. Analysis of various parameters pertaining to combustion performance shows that the ignition and combustion performance of Fujian anthracite was improved as long as the Fujian anthracite was mixed with around 20% biomass.
{"title":"Co-combustion performance analysis of a Fujian anthracite with Cunninghamia lanceolate and Mycorrhizal plants","authors":"Zheng Zou, Yangui Chen, Jieqing Zheng, Xiao-dong Zhang, Hongzhou He","doi":"10.1177/14686783211010966","DOIUrl":"https://doi.org/10.1177/14686783211010966","url":null,"abstract":"The co-combustion characteristics of Fujian anthracite with two biomasses (i.e. Cunninghamia lanceolata) and Mycorrhizal plants in different proportions were investigated using thermogravimetric analysis. The result showed that first, the co-combustion processes of Fujian anthracite with the two biomasses (Cunninghamia lanceolata and Mycorrhizal plants) proceeded in three stages, separation and combustion of volatiles, combustion of fixed carbon in the biomass, and combustion of fixed carbon in Fujian anthracite. Secondly with increasing proportion of biomass, the co-combustion of Fujian anthracite with Cunninghamia lanceolata and Mycorrhizal plants shifted to a low-temperature zone, with a lower ignition temperature, shortened burnout time, and growth of both combustibility index (Ci) and comprehensive combustion index S. Finally, at different mixing proportions, the comprehensive combustion index S during co-combustion of FW with Mycorrhizal plants is always larger than that during co-combustion with Cunninghamia lanceolata; therefore, FW and Mycorrhizal plants exhibit superior comprehensive co-combustion performance to FW and Cunninghamia lanceolata. Analysis of various parameters pertaining to combustion performance shows that the ignition and combustion performance of Fujian anthracite was improved as long as the Fujian anthracite was mixed with around 20% biomass.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76810495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1177/14686783211045834
Jianli Lu, H. Han, Bo Li, Yanjun Han
In the current work, through applying the mixed-ligand generation method, [Bi4Cl8(PDC)2 (2,2′-bpy)4]·2MeCN (1), a fresh bismuth (III)-organic compound synthesized with the solvothermal reactions between 2,2′-bipyridine (2,2′-bpy); 2,6-pyridinedicarboxylic acid (H2PDC); and bismuth chloride. The structural characterization results show that complex 1 features a binuclear discrete structure which is further extended into a 1D chain–like supramolecular network via π–π interactions. Furthermore, the compound’s treatment and nursing application values on pediatric pneumonia was explored and the novel compound’s corresponding mechanism was also investigated. First of all, in our research, the enzyme-linked immunosorbent assay (ELISA) detection kit was employed for the determination of the inflammatory cytokines content released into alveolar lavage fluid. Subsequently, the adenosine 5‘-monophosphate (AMP)–activated protein kinase (AMPK) signaling pathway activation in alveolar epithelial cells was explored exploiting the real-time reverse transcription–polymerase chain reaction (RT-PCR). Molecular docking demonstrated that although multiple pyridine rings are presented in the Bi complex, however, only the carboxylate groups have been observed to interact with the active residues.
{"title":"A new Bi(III)-based coordination complex: Treatment and nursing application values on pediatric pneumonia","authors":"Jianli Lu, H. Han, Bo Li, Yanjun Han","doi":"10.1177/14686783211045834","DOIUrl":"https://doi.org/10.1177/14686783211045834","url":null,"abstract":"In the current work, through applying the mixed-ligand generation method, [Bi4Cl8(PDC)2 (2,2′-bpy)4]·2MeCN (1), a fresh bismuth (III)-organic compound synthesized with the solvothermal reactions between 2,2′-bipyridine (2,2′-bpy); 2,6-pyridinedicarboxylic acid (H2PDC); and bismuth chloride. The structural characterization results show that complex 1 features a binuclear discrete structure which is further extended into a 1D chain–like supramolecular network via π–π interactions. Furthermore, the compound’s treatment and nursing application values on pediatric pneumonia was explored and the novel compound’s corresponding mechanism was also investigated. First of all, in our research, the enzyme-linked immunosorbent assay (ELISA) detection kit was employed for the determination of the inflammatory cytokines content released into alveolar lavage fluid. Subsequently, the adenosine 5‘-monophosphate (AMP)–activated protein kinase (AMPK) signaling pathway activation in alveolar epithelial cells was explored exploiting the real-time reverse transcription–polymerase chain reaction (RT-PCR). Molecular docking demonstrated that although multiple pyridine rings are presented in the Bi complex, however, only the carboxylate groups have been observed to interact with the active residues.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79375987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1177/1468678320982185
Yangui Chen, Hongzhou He, Zhongqing Liu
Accurate thermal decomposition mechanism and kinetic parameters are helpful to analyze the combustion process of flexible polyurethane foam. The thermal decomposition process of flexible polyurethane foam products (amine derivatives) was ignored in the past. Three thermal decomposition mechanisms of flexible polyurethane foam were proposed according to the thermogravimetry experiment of flexible polyurethane foam in the nitrogen atmosphere, two of which included the thermal decomposition of amine derivatives. The global search algorithm was proposed to estimate the kinetic parameters of the thermal decomposition of solid material. The results show that the global search algorithm is efficient and accurate in estimating kinetic parameters. The results also show the thermal decomposition mechanism including the carbodiimide and polycarbondiimide can well describe the thermal decomposition process of flexible polyurethane foam and amine derivatives. The activation energy, pre-exponential factor, and reaction order of flexible polyurethane foam are 187.3 kJ mol−1, 1015.6 s−1, and 1.22, respectively.
{"title":"Application of the global search algorithm to analyze the kinetic mechanism of the thermal decomposition of flexible polyurethane foam","authors":"Yangui Chen, Hongzhou He, Zhongqing Liu","doi":"10.1177/1468678320982185","DOIUrl":"https://doi.org/10.1177/1468678320982185","url":null,"abstract":"Accurate thermal decomposition mechanism and kinetic parameters are helpful to analyze the combustion process of flexible polyurethane foam. The thermal decomposition process of flexible polyurethane foam products (amine derivatives) was ignored in the past. Three thermal decomposition mechanisms of flexible polyurethane foam were proposed according to the thermogravimetry experiment of flexible polyurethane foam in the nitrogen atmosphere, two of which included the thermal decomposition of amine derivatives. The global search algorithm was proposed to estimate the kinetic parameters of the thermal decomposition of solid material. The results show that the global search algorithm is efficient and accurate in estimating kinetic parameters. The results also show the thermal decomposition mechanism including the carbodiimide and polycarbondiimide can well describe the thermal decomposition process of flexible polyurethane foam and amine derivatives. The activation energy, pre-exponential factor, and reaction order of flexible polyurethane foam are 187.3 kJ mol−1, 1015.6 s−1, and 1.22, respectively.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86630042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1007/978-3-030-68574-4
E. Keszei
{"title":"Reaction Kinetics: An Introduction","authors":"E. Keszei","doi":"10.1007/978-3-030-68574-4","DOIUrl":"https://doi.org/10.1007/978-3-030-68574-4","url":null,"abstract":"","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86535642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1177/14686783211020600
Anan Haj Ichia Arisha
The results of density functional theory calculations at the APFD/SDD level are detailed herein in order to study the main steps in the α,β-dehydrogenation of aldehydes and cyclic ketones in the presence of an allylpalladium complex catalyst. The mechanism is believed to proceed via an allylpalladium enolate complex (A) in equilibrium with the carbon-bonded complex (B), followed by β-hydride elimination to yield the allylpalladium hydride coordinated to the α,β-unsaturated carbonyl (complex C). The optimized structures and detailed energy profiles of these intermediates and their corresponding transition states are presented herein. The results indicate that the intermediates and their transition states are more stable in THF solution than in the gas phase. In detail, the energy barriers for the two steps are found to be 25.22 and 11.13 kcal/mol, respectively, in THF, and 29.93 and 9.77 kcal/mol, respectively, in the gas phase.
{"title":"A density functional theory study on the mechanism of the allylpalladium-catalyzed dehydrogenation of aldehydes and cyclic ketones","authors":"Anan Haj Ichia Arisha","doi":"10.1177/14686783211020600","DOIUrl":"https://doi.org/10.1177/14686783211020600","url":null,"abstract":"The results of density functional theory calculations at the APFD/SDD level are detailed herein in order to study the main steps in the α,β-dehydrogenation of aldehydes and cyclic ketones in the presence of an allylpalladium complex catalyst. The mechanism is believed to proceed via an allylpalladium enolate complex (A) in equilibrium with the carbon-bonded complex (B), followed by β-hydride elimination to yield the allylpalladium hydride coordinated to the α,β-unsaturated carbonyl (complex C). The optimized structures and detailed energy profiles of these intermediates and their corresponding transition states are presented herein. The results indicate that the intermediates and their transition states are more stable in THF solution than in the gas phase. In detail, the energy barriers for the two steps are found to be 25.22 and 11.13 kcal/mol, respectively, in THF, and 29.93 and 9.77 kcal/mol, respectively, in the gas phase.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75342908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1177/14686783211027446
Yasmen M. Moghazy, Nagwa MM Hamada, M. F. Fathalla, Yasser R. Elmarassi, Ezzat A. Hamed, Mohamed A. El-Atawy
Reactions of aryl 1-(2,4-dinitronaphthyl) ethers with piperidine in dimethyl sulfoxide at 25oC resulted in substitution of the aryloxy group at the ipso carbon atom. The reaction was measured spectrophotochemically and the kinetic studies suggested that the titled reaction is accurately third order. The mechanism is began by fast nucleophilic attack of piperidine on C1 to form zwitterion intermediate (I) followed by deprotonation of zwitterion intermediate (I) to the Meisenheimer ion (II) in a slow step, that is, SB catalysis. The regular variation of activation parameters suggested that the reaction proceeded through a common mechanism. The Hammett equation using reaction constant σo values and Brønsted coefficient value showed that the reaction is poorly dependent on aryloxy substituent and the reaction was significantly associative and Meisenheimer intermediate-like. The mechanism of piperidinolysis has been theoretically investigated using density functional theory method using B3LYP/6-311G(d,p) computational level. The combination between experimental and computational studies predicts what mechanism is followed either through uncatalyzed or catalyzed reaction pathways, that is, SB and SB-GA. The global parameters of the reactants, the proposed activated complexes, and the local Fukui function analysis explained that C1 carbon atom is the most electrophilic center of ether. Also, kinetics and theoretical calculation of activation energies indicated that the mechanism of the piperidinolysis passed through a two-step mechanism and the proton transfer process was the rate determining step.
{"title":"Understanding the reaction mechanism of the regioselective piperidinolysis of aryl 1-(2,4-dinitronaphthyl) ethers in DMSO: Kinetic and DFT studies","authors":"Yasmen M. Moghazy, Nagwa MM Hamada, M. F. Fathalla, Yasser R. Elmarassi, Ezzat A. Hamed, Mohamed A. El-Atawy","doi":"10.1177/14686783211027446","DOIUrl":"https://doi.org/10.1177/14686783211027446","url":null,"abstract":"Reactions of aryl 1-(2,4-dinitronaphthyl) ethers with piperidine in dimethyl sulfoxide at 25oC resulted in substitution of the aryloxy group at the ipso carbon atom. The reaction was measured spectrophotochemically and the kinetic studies suggested that the titled reaction is accurately third order. The mechanism is began by fast nucleophilic attack of piperidine on C1 to form zwitterion intermediate (I) followed by deprotonation of zwitterion intermediate (I) to the Meisenheimer ion (II) in a slow step, that is, SB catalysis. The regular variation of activation parameters suggested that the reaction proceeded through a common mechanism. The Hammett equation using reaction constant σo values and Brønsted coefficient value showed that the reaction is poorly dependent on aryloxy substituent and the reaction was significantly associative and Meisenheimer intermediate-like. The mechanism of piperidinolysis has been theoretically investigated using density functional theory method using B3LYP/6-311G(d,p) computational level. The combination between experimental and computational studies predicts what mechanism is followed either through uncatalyzed or catalyzed reaction pathways, that is, SB and SB-GA. The global parameters of the reactants, the proposed activated complexes, and the local Fukui function analysis explained that C1 carbon atom is the most electrophilic center of ether. Also, kinetics and theoretical calculation of activation energies indicated that the mechanism of the piperidinolysis passed through a two-step mechanism and the proton transfer process was the rate determining step.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86633511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The reaction mechanism between silacyclopropenylidene and three-membered heterocyclic compounds (azirane and oxirane) has been systematically investigated at the B3LYP/6-311+G* level of theory in order to better understand the reactivity of unsaturated cyclic silylene. Geometry optimizations and vibrational analyses have been conducted for the stationary points on the potential energy surface of the system. Calculations show that the Si-spiroheterocyclic intermediate and four-membered heterocyclic silylene compound could be produced through the insertion process and subsequent dissociation process between silacyclopropenylidene and three-membered heterocyclic compounds. For the insertion process, it is easier for silacyclopropenylidene to insert into C-N bond of azirane than into C-O bond of oxirane. This study is helpful to understand the reactivity of silacyclopropenylidene, the evolution of silicon-bearing molecules in space, and to offer an alternative approach to the formation of enlarged heterocyclic silylene compound.
{"title":"Theoretical study on the reaction between silacyclopropenylidene and three-membered heterocyclic compounds (azirane and oxirane): An alternative approach to the formation of heterocyclic silylene","authors":"Xiaojun Tan, Mengyao Wu, Yilin Wang, Guizhi Shi, Jinsong Gu","doi":"10.1177/1468678320902059","DOIUrl":"https://doi.org/10.1177/1468678320902059","url":null,"abstract":"The reaction mechanism between silacyclopropenylidene and three-membered heterocyclic compounds (azirane and oxirane) has been systematically investigated at the B3LYP/6-311+G* level of theory in order to better understand the reactivity of unsaturated cyclic silylene. Geometry optimizations and vibrational analyses have been conducted for the stationary points on the potential energy surface of the system. Calculations show that the Si-spiroheterocyclic intermediate and four-membered heterocyclic silylene compound could be produced through the insertion process and subsequent dissociation process between silacyclopropenylidene and three-membered heterocyclic compounds. For the insertion process, it is easier for silacyclopropenylidene to insert into C-N bond of azirane than into C-O bond of oxirane. This study is helpful to understand the reactivity of silacyclopropenylidene, the evolution of silicon-bearing molecules in space, and to offer an alternative approach to the formation of enlarged heterocyclic silylene compound.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84546685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A series of APTMS ((3-aminopropyl)trimethoxysilane)-modified silicate MCM-41 adsorbents (x-APTMS/MCM-41, x is the volume of APTMS per 1 g of silicate MCM-41) with different APTMS contents was prepared, and the effects of APTMS content on the desulfurization performance of the APTMS/MCM-41 adsorbents were studied in a fixed adsorption bed using H2S and N2 mixture as a model gas. The as-prepared adsorbents were characterized by X-ray diffraction analysis, N2 adsorption–desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The results showed that all the APTMS-modified x-APTMS/MCM-41 adsorbents retained the mesoporous silica structure of MCM-41. The Brunauer–Emmett–Teller-specific surface area of x-APTMS/MCM-41 increased slightly with increasing x at first and then decreased with further increasing APTMS content. The H2S removal performances of x-APTMS/MCM-41 adsorbents decreased in the order 0.6-APTMS/MCM-41 > 0.7-APTMS/MCM-41 > 0.5-APTMS/MCM-41 > 0.4-APTMS/MCM-41 > 0.8-APTMS/MCM-41. At x = 0.6, the maximum H2S removal rate of 54.2% and H2S saturated capacity of 134.4 mg g−1 were observed. The regeneration experiment of 0.6-APTMS/MCM-41 adsorbent after three times regeneration at 423 K for 3 h in nitrogen confirmed that it possessed a good regenerability.
{"title":"Study on the preparation of amine-modified silicate MCM-41 adsorbent and its H2S removal performance","authors":"J. Zhang, Hua Song, Yanguang Chen, Tianzhen Hao, Feng Li, Dan-dan Yuan, Xueqin Wang, Liang Zhao, Jinsen Gao","doi":"10.1177/1468678319825900","DOIUrl":"https://doi.org/10.1177/1468678319825900","url":null,"abstract":"A series of APTMS ((3-aminopropyl)trimethoxysilane)-modified silicate MCM-41 adsorbents (x-APTMS/MCM-41, x is the volume of APTMS per 1 g of silicate MCM-41) with different APTMS contents was prepared, and the effects of APTMS content on the desulfurization performance of the APTMS/MCM-41 adsorbents were studied in a fixed adsorption bed using H2S and N2 mixture as a model gas. The as-prepared adsorbents were characterized by X-ray diffraction analysis, N2 adsorption–desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The results showed that all the APTMS-modified x-APTMS/MCM-41 adsorbents retained the mesoporous silica structure of MCM-41. The Brunauer–Emmett–Teller-specific surface area of x-APTMS/MCM-41 increased slightly with increasing x at first and then decreased with further increasing APTMS content. The H2S removal performances of x-APTMS/MCM-41 adsorbents decreased in the order 0.6-APTMS/MCM-41 > 0.7-APTMS/MCM-41 > 0.5-APTMS/MCM-41 > 0.4-APTMS/MCM-41 > 0.8-APTMS/MCM-41. At x = 0.6, the maximum H2S removal rate of 54.2% and H2S saturated capacity of 134.4 mg g−1 were observed. The regeneration experiment of 0.6-APTMS/MCM-41 adsorbent after three times regeneration at 423 K for 3 h in nitrogen confirmed that it possessed a good regenerability.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87873460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1177/1468678319825742
Abdelilah Benallou, Habib El Alaoui El Abdallaoui, H. Garmes
The mechanistic nature of a [3+2] cycloaddition reaction involving zwitterionic species has been investigated, and the changes of electron density related to the O–C and C–C bond formation along the intrinsic reaction coordinate have been characterized. This polar [3+2] cycloaddition reaction, which takes place through a non-concerted two-stage one-step mechanism, proceeds with a moderate Gibbs free activation energy of 21 kcal mol−1. The reaction begins by the creation of a pseudoradical centre at the central carbon, first on the dimethyl acetylenedicarboxylate, and second on the nitrone framework. This immediately favours the formation of the first O–C single bond by donation of some electron density of the oxygen atom lone pairs, which represents the most attractive centre in this cycloaddition reaction.
{"title":"An electron localization function analysis of the molecular mechanism and the C–O bond formation in the [3+2] cycloaddition reaction involving zwitterionic type between a nitrone and an electron deficient ethyne","authors":"Abdelilah Benallou, Habib El Alaoui El Abdallaoui, H. Garmes","doi":"10.1177/1468678319825742","DOIUrl":"https://doi.org/10.1177/1468678319825742","url":null,"abstract":"The mechanistic nature of a [3+2] cycloaddition reaction involving zwitterionic species has been investigated, and the changes of electron density related to the O–C and C–C bond formation along the intrinsic reaction coordinate have been characterized. This polar [3+2] cycloaddition reaction, which takes place through a non-concerted two-stage one-step mechanism, proceeds with a moderate Gibbs free activation energy of 21 kcal mol−1. The reaction begins by the creation of a pseudoradical centre at the central carbon, first on the dimethyl acetylenedicarboxylate, and second on the nitrone framework. This immediately favours the formation of the first O–C single bond by donation of some electron density of the oxygen atom lone pairs, which represents the most attractive centre in this cycloaddition reaction.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83525486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1177/1468678319864473
Bilal Achouri, Y. Belmiloud, M. Brahimi
In this work, we focus our attention on chemical reactions confined within carbon nanotubes. As a result of the confinement within carbon nanotubes, novel physical and chemical properties are found for the confined materials. We consider the feasibility of proton transfer inside carbon nanotubes. To do that, we have chosen formamide as the simplest real model for exhibiting the tautomerization in DNA. We have used the quantitative structure–property relationship method, based on geometry optimization and quantum chemical structural descriptors, to illustrate the potential of using the confined space inside carbon nanotubes, which will provide comprehensive information about carbon nanotubes. All calculations have been carried out using density functional theory quantum calculations with the B3LYP functional. The geometries optimized by the Gaussian program were transferred to the computer software DRAGON to calculate pertinent descriptors that could be used in the quantitative structure–property relationship model.
{"title":"Proton transfer reaction confined within carbon nanotubes: Density functional theory and quantitative structure–property relationship analysis","authors":"Bilal Achouri, Y. Belmiloud, M. Brahimi","doi":"10.1177/1468678319864473","DOIUrl":"https://doi.org/10.1177/1468678319864473","url":null,"abstract":"In this work, we focus our attention on chemical reactions confined within carbon nanotubes. As a result of the confinement within carbon nanotubes, novel physical and chemical properties are found for the confined materials. We consider the feasibility of proton transfer inside carbon nanotubes. To do that, we have chosen formamide as the simplest real model for exhibiting the tautomerization in DNA. We have used the quantitative structure–property relationship method, based on geometry optimization and quantum chemical structural descriptors, to illustrate the potential of using the confined space inside carbon nanotubes, which will provide comprehensive information about carbon nanotubes. All calculations have been carried out using density functional theory quantum calculations with the B3LYP functional. The geometries optimized by the Gaussian program were transferred to the computer software DRAGON to calculate pertinent descriptors that could be used in the quantitative structure–property relationship model.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88757753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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