Theoretical analysis of activation parameters in mixed solvents involving various chemical equilibria. Reaction of ethyl iodide with bromide ion in N-methylacetamide-acetonitrile and N-methylacetamide–N,N-dimethylacetamide mixtures

1987 ◽  
Vol 83 (4) ◽  
pp. 1089
Author(s):  
Yasuhiko Kondo ◽  
Shigekazu Kusabayashi
Keyword(s):  
Theoretical Analysis ◽  
Mixed Solvents ◽  
Activation Parameters ◽  
Ethyl Iodide ◽  
Chemical Equilibria ◽  
Bromide Ion

An Assessment of the Method Used to Determine Activation Parameters in L12 Alloys

1998 ◽  
Vol 552 ◽  
Author(s):  
B. Matterstock ◽  
G. Saada ◽  
J. Bonneville ◽  
J. L Martin
Keyword(s):  
Mechanical Properties ◽  
Theoretical Analysis ◽  
Plastic Strain ◽  
Strain Rate ◽  
Characteristic Time ◽  
Constant Strain Rate ◽  
Activation Parameters ◽  
Plastic Strain Rate ◽  
Clear Indication ◽  
Load Relaxation

ABSTRACTThe characterisation of dislocation mechanisms in connection with macroscopic mechanical properties are usually performed through transient tests, such as strain-rate jumps, load relaxations or creep experiments. The present paper includes a careful and complete theoretical analysis of the relaxation and the creep kinetics. We experimentally show that the plastic strain-rate is continuous at the transition between constant strain-rate conditions and both load relaxation and creep test. The product of the plastic strain-rate at the onset of the transient test () with the characteristic time (tk) of the transient is found to be independent of , as theoretically expected. This is a clear indication that the assumptions underlying the theoretical analysis are relevant.

Solvolysis rates in aqueous – organic mixed solvents. V. Kinetics of the alkaline decarboxylation of trichloroacetate ion in water – ethanol solutions

1978 ◽  
Vol 56 (15) ◽  
pp. 2053-2057 ◽  
Author(s):  
El-Hussieny M. Diefallah ◽  
A. M. El-Nadi
Keyword(s):  
Mole Fraction ◽  
Pure Water ◽  
Mixed Solvents ◽  
Activation Parameters ◽  
Solvent Mixtures ◽  
Rate Of Reaction ◽  
Ethanol Addition ◽  
Regular Increase ◽  
Aqueous Organic Mixed Solvents ◽  
Kinetics Of

The kinetics of the alkaline decarboxylation of trichloroacetate ion in ethanol–water solutions have been studied over the temperature range 35.0 to 70.0 °C. The rate of reaction is first order with respect to the trichloroacetate ion and is independent of the concentration of the hydroxide ion. The reactivity is enhanced by increasing the concentration of ethanol in the water–ethanol solutions and the rate of reaction varies with ethanol addition in a nonlinear manner. The rate of reaction increases with the reciprocal of the dielectric constant of the medium and the plot of log k vs. 1/D is approximately linear for solvent mixtures with less than about 0.7 water mole fraction but is strongly curved towards the pure water end. The activation parameters for the reaction show a regular increase in the solvent composition range 0.3 to 1.0 water mole fraction. The results are discussed in terms of the influence of solvent internal pressure and polarity on reactivity and of the increased amount of hydrogen-bonded structure in the water-rich solutions.

A study of the medium effect of mixed solvents; The cyclohexane-nitrobenzene system

1986 ◽  
Vol 51 (9) ◽  
pp. 1942-1947 ◽  
Author(s):  
Taťjana Nevěčná ◽  
Vojtěch Bekárek
Keyword(s):  
Refractive Index ◽  
Spectral Data ◽  
Rate Constants ◽  
Relative Permittivity ◽  
Mixed Solvents ◽  
Ethyl Iodide ◽  
Medium Effect ◽  
Wavelength Band ◽  
The Media

Rate constants of the reaction of triethylamine with ethyl iodide (at 293.15, 313.15, 323.15, and 333.45 K) and wavenumbers of the longest wavelength band maxima of 4-nitroso-N,N-dimethylaniline and 2,6-diphenyl-4-(2,4,6-triphenyl-1-pyridinio)phenoxide were measured in nitrobenzene and thirteen mixtures of nitrobenzene with cyclohexane. The activation characteristics of the reaction of triethylamine with ethyl iodide in these media were calculated, and the correlations of rate constants and spectral data were carried out with functions of relative permittivity and refractive index of the media used and mutually with each other.

Substituent and solvent effects on the reaction between 2,6-Di-t-butyl-α-(3,5-di-t-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)-p-tolyloxyl (galvinoxyl) and phenols

1978 ◽  
Vol 31 (6) ◽  
pp. 1201 ◽  
Author(s):  
N Nishimura ◽  
K Okahashi ◽  
T Yukutomi ◽  
A Fujiwara ◽  
S Kubo
Keyword(s):  
Carbon Tetrachloride ◽  
Binary Mixtures ◽  
Solvent Effects ◽  
Rate Constants ◽  
Isotope Effects ◽  
Mixed Solvents ◽  
Transition States ◽  
Activation Parameters ◽  
Substituted Phenols ◽  
Kinetic Behaviour

Rate constants and associated activation parameters for the reaction of galvinoxyl with substituted phenols were obtained in carbon tetrachloride and in cyclohexane-dioxan binary mixtures. Substantial isotope effects were observed for O-deuterated phenols. The rate constants are correlated with σ+ values. These findings are discussed by considering the polar contribution of substituents to the stabilization of the transition states. In the mixed solvents, the kinetic behaviour is well expressed by the equations which are based on the theory of Kondo and Tokura.

Octahedral cobalt(III) complexes in dipolar aprotic solvents. XI. Anation of cis-chlorodimethylformamidebisethylenediaminecobalt(III) by bromide ion, and solvolysis and isomerization of cis-and trans-bromochlorobisethylenediaminecobalt(III) ions in anhydrous N,N-dimethylformamide

1967 ◽  
Vol 20 (12) ◽  
pp. 2623 ◽  
Author(s):  
IR Lantzke ◽  
DW Watts
Keyword(s):  
Activation Parameters ◽  
Ion Association ◽  
Aprotic Solvents ◽  
Bromide Ion ◽  
Cis And Trans ◽  
Dipolar Aprotic Solvents

The anation of the cis-chlorodimethylformamidebisethylenediaminecobalt(III) ion (cis- [CoCl(DMF) en2]2+) by bromide ion in N,N-dimethylformamide (DMF) has been studied. The reaction has an SNIIP1 mechanism, and when due allowance is made for ion association its activation parameters closely parallel those of other SNIIP anation reactions in DMF. The solvolysis and isomerization of the dichlorobisethylenediaminecobalt(III) ions (cis- and trans-[CoCl2 en2]+) and the bromochlorobisethylenediaminecobalt(III) ions (cis- and trans- CoBrCl en2]+) in DMF have been examined over a range of anion concentration. In all cases solvolysis reactions are important, although direct isomerization appears to become an important path for the reaction of the trans complexes at high anion concentrations. Solvolysis of the cis-[CoCl2 en2]+ ion involves an SN2 mechanism.1 The cis-[CoBrClen2]+, trans-[CoCl2 en2]+, and trans-[CoBrCl en2]+ ions all react by an SN1 mechanism.

Solvolysis rates and activation parameters of phenylchloroformate in water-tetrahydrofuran and water-dioxane mixed solvents

1989 ◽  
Vol 141 ◽  
pp. 1-8 ◽  
Author(s):  
Mahmoud A. Mousa ◽  
El-Hussieny M. Diefallah ◽  
Hassan A. Dessouki ◽  
Shokar T. Atwa
Keyword(s):  
Mixed Solvents ◽  
Activation Parameters

Preface

2008 ◽  
Vol 80 (6) ◽  
pp. iv
Author(s):  
Erich Königsberger
Keyword(s):  
Solution Structure ◽  
Mixed Solvents ◽  
Solution Chemistry ◽  
Ternary Mixtures ◽  
State Transitions ◽  
Biological Macromolecules ◽  
Aqueous Mixtures ◽  
Chemical Equilibria ◽  
International Conference ◽  
The Many

The 30th International Conference on Solution Chemistry (ICSC 30) was held at Murdoch University, Perth, Western Australia, 16-20 July 2007. Under the proficient chairmanship of Prof. Glenn Hefter, about 100 participants from more than 20 countries from all parts of the world gathered down under not only to discuss science but also to enjoy the relaxed Australian lifestyle and the picturesque scenery surrounding Perth.A representative selection of the many excellent and timely contributions presented at the Conference is collected in this issue of Pure and Applied Chemistry. This continues a tradition of regular publication coverage of this series over many years, http://www.iupac.org/publications/pac/conferences/ family/ICSC/, and thus enriches a record of ongoing progress in theoretical and experimental solution chemistry. Subjects covered by ICSC 30 include computer modeling of solution structure and dynamics (Hofer, Bowron); simulation of nanocolloidal suspensions (Turq); ion solvation and association (Buchner); polyelectrolyte hydration (Vlachy); aqueous mixtures of hydrophilic and -phobic ions (Kumar); spin-state transitions in solution (Linert); prediction of multiphase chemical equilibria with applications to hydrometallurgy (Eriksson); chemical speciation of polynuclear complexes (Torres); synthesis, solubility, and stability of minerals (Williams); ternary mixtures involving ionic liquids (MacFarlane); and structure of biological macromolecules in mixed solvents (Yamaguchi). The Conference Editor wishes to thank all authors for their contributions to this issue.The 31st International Conference on Solution Chemistry will be organized by Prof. Bernd M. Rode, Dr. Bernhard Randolf, and Dr. Thomas Hofer in Innsbruck, Austria, 21-25 August 2009 (http://icsc2009.org/).Erich KönigsbergerConference Editor

Kinetics of oxidation of bis(ethylenediamine)mercaptoacetatocobalt(III) and cysteinatobis(ethylenediamine)cobalt(III) ions by peroxodisulphate in aqueous-nonaqueous mixed solvents

1986 ◽  
Vol 51 (5) ◽  
pp. 1049-1060 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko ◽  
Ivana Matejeková
Keyword(s):  
Perchloric Acid ◽  
Transfer Functions ◽  
Mixed Solvents ◽  
Sodium Perchlorate ◽  
Activation Parameters ◽  
Solvent System ◽  
Butyl Alcohol ◽  
Complex Ions ◽  
Kinetics Of Oxidation ◽  
Kinetics Of

The kinetics of oxidation in the first step was studied for coordination-bonded sulphur in the cysteinatobis(ethylenediamine)cobalt(III) and bis(ethylenediamine)mercaptoacetatocobalt(III) ions using peroxodisulphate as oxidant. The effect of the acid-base equilibria of the reactants was established based on the dependences of the rate constant and the thermodynamic activation parameters ΔH and ΔS on perchloric acid concentration. The effect of ionic strength at various perchloric acid concentrations, was examined for the two complex ions. The combined effect of perchloric acid and sodium perchlorate was investigated in water-tert-butyl alcohol and water-ethylene glycol solutions. The transfer functions were calculated from the changes in the solubility of the reactants on passing from aqueous to the mixed aqueous-nonaqueous solutions, and the role of solvation during the oxidation of the complexes by peroxodisulphate was assessed based on the dependences of the transfer functions on the nonaqueous component content of the solvent system.

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