Progress in Reaction Kinetics and Mechanism最新文献_第9页

Behaviour Modelling of Organic Bases in the Oxyalkylation Reaction of Proton-Containing Nucleophiles 含质子亲核试剂氧烷基化反应中有机碱的行为模拟

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-06-01 DOI: 10.3184/146867818X15161889114501

S. Bakhtin, E. Shved, Yuliia Bespal’ko, Yu. Z. Stepanova

{"title":"Behaviour Modelling of Organic Bases in the Oxyalkylation Reaction of Proton-Containing Nucleophiles","authors":"S. Bakhtin, E. Shved, Yuliia Bespal’ko, Yu. Z. Stepanova","doi":"10.3184/146867818X15161889114501","DOIUrl":"https://doi.org/10.3184/146867818X15161889114501","url":null,"abstract":"The mechanism of action of nucleophilic and non-nucleophilic bases in the system “acetic acid (HOAc) – epichlorohydrin (ECH) – R3X (R = alkyl, X = N, P)” has been studied. The observed orders of the reaction with respect to the components were found. It has been proved that the catalytic activity of the starting bases is determined by their nucleophilicity, rather than basicity. It is shown that the crucial stage of the reaction is the quaternisation of the starting base with the formation of a reactive intermediate, the acetate anion. Monitoring of possible paths of oxirane ring-opening by the initial base and the acetate anion was carried out. The behaviour of the model base, triphenylphosphine, in the quaternisation reaction was studied by UV spectroscopy. The rate constants of quaternisation in the reaction of tribenzylamine and triphenylphosphine with ECH have been estimated. The activation parameters of the stages of oxirane ring-opening by trimethylamine and the acetate anion were calculated using a quantum chemical method. It has been shown that the starting base attacks only the activated oxirane, while the acetate anion is capable of nucleophilic opening of both activated and non-activated ECH rings. A scheme for the catalytic opening of the oxirane ring by the bases in the system “ECH – HOAc – R3X” is proposed, which includes a series of both consecutive and parallel stages leading to the formation of the reaction product.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":"42 1","pages":"121 - 135"},"PeriodicalIF":0.7,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89155813","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}

引用次数: 6

Hydroformylation of Dicyclopentadiene to Monoformyltricyclodecenes over Supported Ultra-Low Content Rh Catalysts 负载型超低含量Rh催化剂上双环戊二烯氢甲酰化制单酰基三环癸烯

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-06-01 DOI: 10.3184/146867818X15233705894356

Chengyang Li, Hongyi Li, Libo Zhang, Yubo Ma, Tianfu Wang

引用次数: 1

Effects of Some Operating Parameters on Sorption and Desorption Kinetics Related to Spotted Golden Thistle Stalks and Methylene Blue; Isotherm Study at Optimal pH and Sorbent Regeneration 一些操作参数对斑点金蓟茎和亚甲基蓝吸附解吸动力学的影响最佳pH和吸附剂再生的等温研究

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-06-01 DOI: 10.3184/146867818X15233705894365

Z. S. Bereksi, H. Benaïssa

{"title":"Effects of Some Operating Parameters on Sorption and Desorption Kinetics Related to Spotted Golden Thistle Stalks and Methylene Blue; Isotherm Study at Optimal pH and Sorbent Regeneration","authors":"Z. S. Bereksi, H. Benaïssa","doi":"10.3184/146867818X15233705894365","DOIUrl":"https://doi.org/10.3184/146867818X15233705894365","url":null,"abstract":"In this work, the sorptive removal assessment of methylene blue by spotted golden thistle stalks was enhanced. Sorption was positively impacted by increasing temperature, initial pH or ionic strength. The sorbent isoelectrical point is 2.6 according to zeta potential measurements. The Elovich and Avrami models best fitted the sorption kinetic data; and an original prediction of equilibrium time is proposed. At 25 °C and for optimal initial pH = 7, the experimental maximal sorption capacity is 75 mg g−1. The Langmuir, Redlich–Peterson, Sips and Tóth models led to good correlations of isothermal data. Desorption percentages are important in both mineral and organic acidic media; the highest levels up to 91% were recorded for 1 × 10−2 M HCl solutions. The pseudo second-order model fitted satisfactorily the desorption kinetics. An innovative concept of regeneration is proposed, which promises significant savings of eluent and operating time. The sorbent regeneration assessment showed constant uptake abilities after five cycles of use.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":"16 1","pages":"173 - 188"},"PeriodicalIF":0.7,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87006304","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}

引用次数: 2

Kinetics and Mechanism of Alkaline Hydrolysis of N-(o-Aminophenyl)Phthalimide in the Presence and Absence of Cationic Micelles and Sodium Salts of Aliphatic Acids N-(邻氨基苯基)邻苯二胺在阳离子胶束和脂肪酸钠盐存在和不存在情况下的碱性水解动力学和机理

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-06-01 DOI: 10.3184/146867818X15161889114510

W. Ahmad, I. I. Fagge, Yoke-Leng Sim, Mohammad Niyaz Khan

引用次数: 0

Effect of Reactivity on Kinetics and a Mechanistic Investigation of the Reaction between Dimethyl Acetylenedicarboxylate and 1,3-Dicarbonyl Compounds in the Presence of a Catalyst: A Spectrophotometric Approach 反应活性对催化剂存在下二甲基乙酰二羧酸酯与1,3-二羰基化合物反应动力学的影响及机理研究:分光光度法

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-03-01 DOI: 10.3184/146867818X15161889114439

Mahdieh Darijani, S. Habibi‐Khorassani, M. Shahraki

{"title":"Effect of Reactivity on Kinetics and a Mechanistic Investigation of the Reaction between Dimethyl Acetylenedicarboxylate and 1,3-Dicarbonyl Compounds in the Presence of a Catalyst: A Spectrophotometric Approach","authors":"Mahdieh Darijani, S. Habibi‐Khorassani, M. Shahraki","doi":"10.3184/146867818X15161889114439","DOIUrl":"https://doi.org/10.3184/146867818X15161889114439","url":null,"abstract":"A kinetic and mechanistic investigation, using conventional UV-Vis spectrophotometry, of the reaction between dimethyl acetylenedicarboxylate (DMAD) and 1,3-dicarbonyl compounds including acetylacetone (ACAC) and dibenzoylmethane (DBM), has been conducted in a methanol environment with triphenylarsine (TPA) acting as a catalyst. Previously, in a similar reaction, triphenylphosphine (TPP) (instead of TPA) had been employed as a reactant (not a catalyst) for the generation of an ylide (final product). In the present work, of significance is the differential behaviour of TPA which, as a catalyst in the reaction environment, leads to a cyclopropane compound. Of other significance is the different behaviours of the two reactants in the kinetics and mechanism of the reaction. In previous work, TPP acted as a weak nucleophile (a reactant), so the first step of the reaction was recognised as the rate-determining step (RDS). Here, TPA reacts as a stronger nucleophile and a catalyst, resulting in the fourth step of the reaction (step4, k4, a proton transfer process) being recognised as the RDS. The reaction followed second-order kinetics. The proposed mechanism was adapted in accord with the experimental results and the steady-state assumption. The results showed that the reaction rate decreases in the presence of DBM, which participates in the second step (step2), compared to ACAC when it is present as another 1,3-dicarbonyl compound (structural effect). In addition, in previous work, the partial order of the reaction with respect to the 1,3-dicarbonyl compound was zero, while it is one in the present work. As a significant result, not only did a change in the structure of one of the reactants (TPA instead of TPP) create a different product, but also the kinetics and reaction mechanism changed. In addition, the reaction is enthalpy-controlled.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":"20 1","pages":"79 - 90"},"PeriodicalIF":0.7,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86848735","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}

引用次数: 9

Kinetic Studies of the Reactions between Dichlorido(1,2-Diaminoethane)Zinc(II) and Biologically Relevant Nucleophiles in the Presence of Chloride 氯离子存在下二氯(1,2-二氨基乙烷)锌(II)与亲核试剂反应动力学研究

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-03-01 DOI: 10.3184/146867818X15066862094897

T. Soldatović, Enisa Selimović

{"title":"Kinetic Studies of the Reactions between Dichlorido(1,2-Diaminoethane)Zinc(II) and Biologically Relevant Nucleophiles in the Presence of Chloride","authors":"T. Soldatović, Enisa Selimović","doi":"10.3184/146867818X15066862094897","DOIUrl":"https://doi.org/10.3184/146867818X15066862094897","url":null,"abstract":"The mole-ratio method was used for determining metal–ligand stoichiometry for the reaction between [ZnCl2(en)] (where en = 1,2-diaminoethane or ethylenediamine) and chloride ion at pH 7.2. The results have shown step-wise formation of 1:1 and 1:2 complexes and indicate additional coordination of chloride ions in the first coordination sphere. The kinetics of ligand substitution reactions of the zinc(II) complex and biologically relevant nucleophiles such as inosine-5′-monophosphate (5′-IMP), guanosine-5′-monophosphate (5′-GMP), L-methionine (L-Met), glutathione (GSH) and DL-aspartic acid (DL-Asp) were investigated at pH 7.2 as a function of nucleophile concentration in the presence of 0.010 M NaCl. The reactions were followed under pseudo first-order conditions by UV-Vis spectrophotometry. The substitution reactions include two steps of consecutive displacement of chlorido ligands and changes in coordination geometry. In the presence of an excess of chloride, the octahedral complex anion [ZnCl4(en)]2- formed. The first step of the substitution reactions could be interpreted as substitution of the axial chlorido ligands in the cis position to bidentate ethylenediamine by the biologically relevant nucleophiles, while the second step could be interpreted as substitution of the equatorial chlorido ligand. The order of reactivity of the investigated nucleophiles for the first reaction step is 5′-IMP > GSH > L-Met > DL-Asp > 5′-GMP, while for the second reaction step the order of reactivity is GSH > L-Met > 5′-IMP > DL-Asp > 5′-GMP.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":"1 1","pages":"53 - 61"},"PeriodicalIF":0.7,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90115301","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}

引用次数: 3

Nuclease Activity of Diaza-Crown Ether Complexes of Cerium(III) with Different Functional Groups as Side Arms 以不同官能团为侧臂的铈(III)二氮冠醚配合物的核酸酶活性

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-03-01 DOI: 10.3184/146867818X15161889114448

Bingying Jiang, Shulan Cai, Jia‐qing Xie, Fa-mei Feng

{"title":"Nuclease Activity of Diaza-Crown Ether Complexes of Cerium(III) with Different Functional Groups as Side Arms","authors":"Bingying Jiang, Shulan Cai, Jia‐qing Xie, Fa-mei Feng","doi":"10.3184/146867818X15161889114448","DOIUrl":"https://doi.org/10.3184/146867818X15161889114448","url":null,"abstract":"Cerium(III) complexes of two ligands of a diaza-crown ether with different functional groups as side arms were synthesised and characterised. The catalytic ability of the cerium(III) complexes for pUC19 DNA cleavage was investigated and compared using agarose gel electrophoresis. The results indicate that the catalytic activity of the complex CeL2 [L2 = 2,2′- (1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl) diacetamide] with two carbamoylmethyl groups is significantly higher than the complex CeL1 [L1 = 2,2′- (1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl) diethanol] with two hydroxyethyl groups under the same conditions. The optimum catalytic concentrations of CeL1 and CeL2 were 7.69 × 10−5 and 3.08 × 10−5 mol L−1 respectively and excessively high concentrations of the complexes can reduce their catalytic efficiency due to the formation of inactive μ-hydroxo dimers. The optimum catalytic acidities of CeL1 and CeL2 were pH 7.0 and 7.5 respectively and excessively high pH of the reaction system can reduce the catalytic efficiency of the complexes due to the formation of cerium(III) hydroxide. DNA cleavage promoted by the two complexes takes place via the same hydrolytic pathway and so the activity difference of the two complexes is attributed to the stability of the complexes, rather than the catalytic mechanism.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":"5 1","pages":"91 - 99"},"PeriodicalIF":0.7,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73928970","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}

引用次数: 1

Kinetics and Mechanism of Counterionic Salt-Catalysed Piperidinolysis of Anionic Phenyl Salicylate in the Presence of Cationic–Nonionic Mixed Micelles 阳离子-非离子混合胶束存在下，反离子盐催化阴离子水杨酸苯酯水解动力学及机理

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-03-01 DOI: 10.3184/146867818X15066862094888

I. I. Fagge, W. Ahmad, Sharifuddin Bin Md Zain, M. Khan

{"title":"Kinetics and Mechanism of Counterionic Salt-Catalysed Piperidinolysis of Anionic Phenyl Salicylate in the Presence of Cationic–Nonionic Mixed Micelles","authors":"I. I. Fagge, W. Ahmad, Sharifuddin Bin Md Zain, M. Khan","doi":"10.3184/146867818X15066862094888","DOIUrl":"https://doi.org/10.3184/146867818X15066862094888","url":null,"abstract":"The quantitative correlation of counterion-affinity to aqueous hexadecyltrimethylammonium bromide (HDAB, cationic micelles/nanoparticles) and the counterion-induced HDAB micellar growth, in the presence of different amounts of poly(ethylene glycol hexadecyl ether) (C16E20, nonionic surfactant), was achieved by the use of a semi-empirical kinetic (SEK) method. The values of the ratio of cationic HDAB, as well as mixed HDAB–C16E20, micellar binding constants of X and Br, KX/KBr (= KXBr or RXBr) for X = 4-ClC6H4CO2-, were obtained by the SEK method. The concentration range (0.006–0.015 M) of pure HDAB was found to have no influence on the values of KXBr or RXBr. These observations were also recorded upon addition of a nonionic surfactant, C16E20, in an aqueous solution of HDAB. The mean value of KXBr or RXBr obtained in the presence of pure HDAB (KXBr or RXBr = 50.3) is 2.3 times larger than that in the presence of mixed HDAB–C16E20 (mKXBr or mRXBr = 21.7). From rheometric measurements of aqueous HDA+/4-ClC6H4CO2- with 0.015 M HDAB, single symmetric maxima (at both 25 and 35 °C) were obtained at [4-ClC6H4CO2Na] = 0.03 M. This is evidence for the existence of wormlike micelles/nanoparticles. However, the absence of a maximum in rheometric data for aqueous HDA+/C16E20/4-ClC6H4CO2- with 0.015 M HDAB and 0.006 M C16E20 at various [4-ClC6H4CO2Na] revealed the existence of spherical micelles.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":"121 4 1","pages":"41 - 52"},"PeriodicalIF":0.7,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84084160","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}

引用次数: 0

A Compact Reaction Mechanism of Methane Oxidation at High Pressures 高压下甲烷氧化的紧凑反应机理

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-03-01 DOI: 10.3184/146867818X15066862094914

V. Zhukov, Alan Kong

引用次数: 23

‘Green Tide’ to Biochar: Preparation and Adsorption Isotherms for Three Typical Organic Pollutants 从“绿潮”到生物炭:三种典型有机污染物的制备和吸附等温线

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2018-03-01 DOI: 10.3184/146867818X15066862094879

Yuhui Ma, Jing Wang, Yushan Zhang

{"title":"‘Green Tide’ to Biochar: Preparation and Adsorption Isotherms for Three Typical Organic Pollutants","authors":"Yuhui Ma, Jing Wang, Yushan Zhang","doi":"10.3184/146867818X15066862094879","DOIUrl":"https://doi.org/10.3184/146867818X15066862094879","url":null,"abstract":"Enteromorpha prolifera (EP), the main source contributing to the outbreak of ‘green tide’, was used as the raw material to prepare biochars by pyrolysis. The biochars were analysed using N2-adsorption and Fourier transform infrared (FTIR) spectroscopy. The pyrolysis process was investigated by thermogravimetric analysis coupled with FTIR. The adsorption capacities of the biochars were compared in terms of removal efficiencies of methylene blue (MB), oxytetracycline (OTC) and humic acid (HA). The adsorption isotherms of the three organics by the optimum biochar were investigated. The results showed that the Brunauer–Emmett–Teller surface area of the biochar increased from 36 to 643 m2 g−1 with increasing pyrolysis temperature. The surface functional groups contained in EP were damaged during pyrolysis, while–N=O, S=O and C=N groups were formed on the biochar surface. Decomposition of EP resulted in the vigorous release of gaseous products at 240 °C, including CO2, H2O, aldehydes, ethers, aliphatic amines, sulfones and alcohols. CO2 was released due to the decomposition of carbonates above 700 °C and the in situ reduction of CO2 by carbon contained in the biochar was responsible for the high surface area of the biochar prepared at 750 °C (EPC750). EPC750 had the highest adsorption capacities for MB, OTC and HA among the biochars. The adsorption equilibrium data for MB and OTC onto EPC750 followed the Langmuir model with monolayer adsorption capacities of 138.89 and 103.31 mg g−1 respectively. The adsorption data for OTC also exhibited good agreement with the Freundlich model, suggesting the adsorption process was controlled by multiple mechanisms. The adsorption of HA by EPC750 followed the Freundlich model and the maximum adsorption capacity reached 64.27 mg g−1 under the experimental conditions.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":"98 1","pages":"30 - 40"},"PeriodicalIF":0.7,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80994202","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}

引用次数: 6