Kinetics of the Thermal Decomposition of Substituted Cyclic Organic Peroxides in Toluene Solution: Substituent Effects on the Reaction Rates and the Activation Parameters of the Unimolecular Reactions

Heterocycles ◽  
2004 ◽  
Vol 63 (10) ◽  
pp. 2231 ◽  
Author(s):  
Adriana I. Cañizo ◽  
Gladys N. Eyler ◽  
Carmen M. Mateo ◽  
Elida E. Alvarez ◽  
Rosa K. Nesprías
Keyword(s):  
Thermal Decomposition ◽  
Substituent Effects ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Toluene Solution ◽  
Organic Peroxides ◽  
Unimolecular Reactions ◽  
Kinetics Of

scholarly journals Reactivity of Phenol and Aniline towards Quinolinium Chloro Chromate: A Comparative Oxidation Kinetic Study

2015 ◽  
Vol 59 ◽  
pp. 81-92
Author(s):  
Seplapatty Kalimuthu Periyasamy ◽  
H. Satham Hussain ◽  
R. Manikandan
Keyword(s):  
Oxidation Kinetic ◽  
Activation Parameters ◽  
Dipole Interaction ◽  
Reaction Rates ◽  
Hydrogen Ion ◽  
Aqueous Acetic Acid ◽  
Acetic Acid Medium ◽  
First Order ◽  
Different Temperatures ◽  
Kinetics Of

The kinetics of Oxidation of Phenol and aniline by quinolinium Chlorochromate (QCC) in aqueous acetic acid medium leads to the formation of quinone and azobenzene respectively. The reactions are first order with respect to both Phenol and aniline. The reaction is first order with respect to quinolinium chlorochromate (QCC) and is catalyzed by hydrogen ion. The hydrogen-ion dependence has the form: kobs = a+b [H+]. The rate of oxidation decreases with increasing dielectric constant of solvent, indicating the presence of an ion-dipole interaction. The reaction does not induced the polymerization of acrylonitrile. The retardation of the rate by the addition of Mn2+ ions confirms that a two electron transfer process is involved in the reaction. The reaction rates have been determined at different temperatures and the activation parameters have been calculated. From the above observations kinetic results a probable mechanism have been proposed.

A KINETICS AND MECHANISTIC STUDY OF THE OXIDATION OF L-ARGININE BY QDC IN DMF-WATER MEDIUM

2021 ◽  
pp. 11-12
Author(s):  
Deepika Jain ◽  
Shilpa Rathor
Keyword(s):  
Perchloric Acid ◽  
Reaction Rate ◽  
Main Product ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Mechanistic Study ◽  
Water Medium ◽  
Volume Percentage ◽  
Kinetics Of Oxidation ◽  
Kinetics Of

The present paper describes the kinetics of oxidation of l-Arginine by QDC in the presence of perchloric acid in 30% DMF-H O(v/v) medium at 2 + 40⁰C spectrophotometrically at λ =354nm. The reaction is rst order with respect to [QDC], [H ], and [substrate]. The reaction rate increased with max increasing volume percentage of DMF in reaction mixture. Michaelis- Menten type kinetic was observed with l-Arginine. The reaction rates were studied at different temperature and the activation parameters has been computed. The main product was identied as Cr (III) and 4-Guanidino buteraldehyde.

Substituent Effects in Electron Transfer Reactions: The Preparation and Chromium(II) Reduction of 3-Formylpentane-2,4-dionatobis(ethylenediamine)cobalt(III). Preparation of the Linkage Isomer 2-Acetylbutane-1,3-dionatobis(ethylenediamine)cobalt(III)

1975 ◽  
Vol 53 (8) ◽  
pp. 1154-1164 ◽  
Author(s):  
Robert J. Balahura ◽  
N. A. Lewis
Keyword(s):  
Electron Transfer ◽  
Acidic Solution ◽  
Substituent Effects ◽  
Activation Parameters ◽  
Transfer Reactions ◽  
Linkage Isomers ◽  
A Value ◽  
Parent Complex ◽  
Kinetics Of ◽  
Sphere Mechanism

The preparation of the linkage isomers, 3-formylpentane-2,4-dionatobis(ethylenediamine)cobalt(III), (1), and 2-acetylbutane-1,3-dionatobis(ethylenediamine)cobalt(III), (2), are described. The kinetics of the reaction of Cr(OH2)62+ with 1 and the parent complex, 2,4-pentanedionatobis(ethylenediamine)cobalt(III), (3), have been studied spectrophotometrically in acidic solution. For 1, the reduction is described by the rate law −d ln [Co(III)complex]/dt = k[Cr2+], and k = 0.0863 M−1 s−1 at 25 °C, μ = 1.0 M (LiClO4). The activation parameters for this reaction were found to be ΔH≠ = 9.9 ± 0.5 kcal mol−1 and ΔS≠ = −30 ± 3 e.u. The reaction proceeded by an inner-sphere mechanism and the product of this reaction was isolated and characterized as 2-acetylbutane-1,3-dionatotetraaquochromium(III). The linkage isomer of this complex was also prepared. The parent complex (3) was not reduced by Cr(OH2)62+ at an observable rate and an upper limit for the rate constant of this reaction was assigned a value of 10−4–10−6M−1s−1 at 25 °C. The ability of the formyl group to enhance the rate of electron transfer is discussed, and the chromium(II) reduction studies of related chelated systems are compared with the results obtained in this investigation.

Kinetics of hydrosilylation of tert-butylphenylketone by diphenylsilane catalysed by [Rh(1,5-COD)(-)-DIOP]+ClO-4

1980 ◽  
Vol 45 (8) ◽  
pp. 2224-2239 ◽  
Author(s):  
Ivan Kolb ◽  
Jiří Hetflejš
Keyword(s):  
Activation Parameters ◽  
Reaction Rates ◽  
Reaction Model ◽  
Initial Reaction ◽  
Title Reaction ◽  
Rate Determining Step ◽  
Kinetic Isotope ◽  
Arene Complex ◽  
Kinetics Of

Kinetic analysis of the title reaction has been made by the method of initial reaction rates. On the basis of the rate data, kinetic isotope effect and spectroscopic study of the reaction of the organosilicon hydride with the catalyst, the reaction model was proposed involving the following steps: the displacement of the diene by reaction with the silicon hydride from a rhodium-arene complex in an induction period of the hydrosilylation, the oxidative addition of the organosilicon hydride to the rhodium-arene complex, followed by the interaction of the ketone with the silylhydridorhodium (III) species in the rate determining step. The process is characterized by the following activation parameters: ΔU = 54.5 ± 8.5 kJ mol-1 and ΔS = -88± 25 J mol-1.K-1. The significant role of the entropic factor was supported by the analysis of the temperature dependence of the asymmetric efficiency of the catalyst.

scholarly journals Kinetics and Mechanism of Thermal Decomposition of 1-R-Substituted bis(1,1-Dinitromethyl-3-Nitro- 1,2,4-Triazole-5-yl)

2020 ◽  
pp. 25-30
Author(s):  
Lyudmila А. Kruglyakova ◽  
Rudolf S. Stepanov ◽  
Konstantin V. Pekhotin ◽  
Oksana А. Golubtsova
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Activation Parameters ◽  
Decomposition Kinetics ◽  
Mechanism Of Thermal Decomposition ◽  
Limiting Stage ◽  
Manometric Method ◽  
Steric Constant ◽  
Kinetics Of ◽  
Constant Activation Energy

Thermal decomposition kinetics of 1-substituted bis(1,1-dinitromethyl-3-Nitro-1,2,4-triazole- 5-yl) in solution of 1,3-dinitrobenzene is studied with manometric method under isothermal conditions. The limiting stage of thermal decomposition is homolytic break of C-NO2 bond in gem-dinitromethyl group; activation parameters of this stage are calculated. The reactivity of investigated compounds is analyzed. Correlation dependences between logarithm of rate constant, activation energy and steric constant of substituent R are obtained

Kinetics and Mechanism of the 2+ 2 Cycloaddition of Tetracyanoethylene to 2,5-Dimethyl-2,4-Hexadiene

1988 ◽  
Vol 43 (5) ◽  
pp. 435-441 ◽  
Author(s):  
Adel N. Asaad ◽  
Gunnar Aksnes
Keyword(s):  
Complex Formation ◽  
Transition State ◽  
Thermodynamic Parameters ◽  
Cycloaddition Reaction ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Kinetics And Mechanism ◽  
Eda Complex ◽  
Kinetics Of ◽  
Cyclobutane Derivative

The kinetics of the 2 + 2 cycloaddition reaction between tetracyanoethylene and 2,5-dimethyl- 2,4-hexadiene in different solvents has been studied by following the disappearance of the intermediate EDA-complex spectrophotometrically. It is concluded that the EDA-complex is transformed through a concerted cyclicpolar transition state to give the vinyl cyclobutane derivative (III). The effects of various solvents on the reaction rates have been analysed using a multiparameter approach. The thermodynamic parameters (ΔH0 and ΔS0), of EDA-complex formation and the activation parameters (ΔH# and ΔS#) of the cycloaddition have been discussed.

Mono, Di and Trifunctional Cyclic Organic Peroxides: The Effect of Substituents and Ring Size on their Thermolysis in 1,4-dioxan

2013 ◽  
Vol 66 (9) ◽  
pp. 1080 ◽  
Author(s):  
Rosa Nesprias ◽  
Gladys Eyler ◽  
Adriana Cañizo
Keyword(s):  
Thermal Decomposition ◽  
Statistical Treatment ◽  
Activation Parameters ◽  
Decomposition Reaction ◽  
Order Kinetic ◽  
Organic Peroxides ◽  
Solvent Interaction ◽  
Kinetic Behaviour ◽  
First Order ◽  
Thermal Stability Of

The thermal decomposition reaction of cyclic organic peroxides was studied in 1,4-dioxan at initial concentrations between ~10–4 and 10–2 mol L–1 and at a temperature interval between 100 and 170°C, according to the thermal stability of each compound. The kinetic behaviour observed in all systems studied follows a pseudo first order kinetic law up to at least ~86 % of peroxide conversion. An important substituent effect is operative on the rate constant values and consequently on the activation parameters of the thermal decomposition reaction. The application of different treatments (compensation affect or a statistical treatment) on the kinetic data shows the existence of two sets of cyclic peroxides with comparable kinetic behaviour. Different peroxide–solvent interaction mechanisms can be considered within each series.

scholarly journals Kinetics of multi-step processes of thermal degradation of Co(II) complex with N-benzyloxycarbonylglycinato ligand. Deconvolution of DTG curves

2014 ◽  
Vol 46 (1) ◽  
pp. 37-53 ◽  
Author(s):  
M. Sumar-Ristovic ◽  
D.M. Minic ◽  
V. Blagojevic ◽  
K. Andjelkovic
Keyword(s):  
Thermal Decomposition ◽  
Activation Parameters ◽  
Elementary Step ◽  
Elementary Steps ◽  
Master Plot ◽  
Thermodynamic Activation Parameters ◽  
Ikp Method ◽  
Kinetic Triplet ◽  
Reaction Models ◽  
Kinetics Of

Thermal decomposition of Co(II) complex with N-benzyloxycarbonylglycinato ligand, [Co(N-Boc-gly)2(H2O)4]?2H2O, in non-isothermal conditions occurs in three complex steps. In order to investigate detail kinetics of first two steps, dehydration and ligand degradation, DTG curves were deconvoluted using product of Gaussian and Lorentzian function. It was shown that process of complex dehydration consists of three, while process of ligand fragmentation consist of five elementary steps. For elementary steps the kinetic triplet (Ea, Z and f(?)) was determinated. Kinetic parameters were obtained by application of IKP method. On the basis of M?lek?s criteria and Sest?k-Berggren's method, Sest?k-Berggren's model, f(?)=?M(1-?)N was suggested for all elementary steps, while Master plot method and Perez- Maqueda criteria confirmed suggested reaction models. The thermodynamic activation parameters were calculated for process of complex dehydration, and lifetime for first elementary step of the dehydration and ligand degradation processes was estimated.

Kinetics of Oxidation of Benzaldehydes by Quinolinium Dichromate

2003 ◽  
Vol 58 (12) ◽  
pp. 1201-1205 ◽  
Author(s):  
Hesham A. A. Medien
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Water Medium ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Different Temperatures ◽  
Acetic Acid Water ◽  
Kinetics Of

Quinolinium dichromate (QDC) in sulfuric acid oxidizes benzaldehydes to the corresponding acids in a 50% (v/v) acetic acid-water medium. The reaction is first order each in [QDC], [substrate] and [H+]. The reaction rates have been determined at different temperatures and the activation parameters calculated. The rate decreases with an increase in the water content of the medium. The effects of substituents have been studied. A suitable mechanism is proposed.

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