Kinetics and mechanism of the reaction of iron(III) and 2,2,6,6-tetramethyl-3,5-heptanedione in aqueous solution

1988 ◽  
Vol 53 (5) ◽  
pp. 976-986 ◽  
Author(s):  
José M. Hernando ◽  
Carlos Blanco ◽  
Manuel Mateo
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Kinetics And Mechanism ◽  
Experimental Results ◽  
First Order ◽  
Complex Stoichiometry ◽  
Complexation Process ◽  
Mechanism Of The Reaction

In this work the kinetic of formation of (2,2,6,6-tetramethyl-3,5-heptanedione)iron(III) complex (stoichiometry 1 : 1) has been studied in aqueous solution. It was found that the reaction is of first order with respect to diketone. The influence of several factors such as reagent concentrations, pH, ionic strength and temperature was systematically examined. A mechanism SN1 is proposed for the complexation process that accounts successfully for the experimental results.

The kinetics and mechanism of the reaction between nickel(II) and dithiocarbamate ions in dimethyl sulfoxide. Evidence for the ID mechanism for a bidentate uninegative ligand

1978 ◽  
Vol 31 (12) ◽  
pp. 2581 ◽  
Author(s):  
PJ Nichols ◽  
MW Grant
Keyword(s):  
Fourier Transform ◽  
Ionic Strength ◽  
Dimethyl Sulfoxide ◽  
Excellent Agreement ◽  
Rate Constants ◽  
Second Order ◽  
Kinetics And Mechanism ◽  
First Order ◽  
Temperature Dependences ◽  
Mechanism Of The Reaction

13C Fourier-transform N.M.R. has been used to measure the rate of exchange of dimethyl sulfoxide with hexakis(dimethyl sulfoxide)nickel(II) cation. The parameters obtained, kex(25°C)(9.8�4.6) × 103 s-1, ΔH‡ 50�2 kJ mol-1 and ΔS‡ 0�4 J K-1 mol-1, are in excellent agreement with those of the most recent 1H N.M.R. study. The reaction between Ni(Me2SO)62+ and diethyldithiocarbamate (dtc-) gives only Ni(dtc)2. When dtc- is in excess, the rate of formation of Ni(dtc)2 is first order in Ni2+ and dtc-. The ionic-strength and temperature dependences of the second-order rate constants are consistent with the rate-determining formation of an unstable Ni(dtc)+ complex by an ID mechanism.

Kinetics and mechanism of the reaction of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione

1990 ◽  
Vol 55 (8) ◽  
pp. 1984-1990 ◽  
Author(s):  
José M. Hernando ◽  
Olimpio Montero ◽  
Carlos Blanco
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics And Mechanism ◽  
Kinetic Constants ◽  
Steric Factors ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reactions of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione to form the corresponding monocomplexes have been studied spectrophotometrically in the range 5 °C to 16 °C at I 25 mol l-1 in aqueous solution. In the proposed mechanism for the two complexes, the enol form reacts with the metal ion by parallel acid-independent and inverse-acid paths. The kinetic constants for both pathways have been calculated at five temperatures. Activation parameters have also been calculated. The results are consistent with an associative activation for Fe(H2O)63+ and dissociative activation for Fe(H2O)5(OH)2+. The differences in the results for the complexes of heptanediones studied are interpreted in terms of steric factors.

Kinetics and mechanism of the reaction between trans-dioxotetracyanotungstate(IV) and azide in aqueous solution

1986 ◽  
Vol 25 (26) ◽  
pp. 4639-4642 ◽  
Author(s):  
Johann G. Leipoldt ◽  
Rudi Van Eldik ◽  
Stephen S. Basson ◽  
Andreas Roodt
Keyword(s):  
Aqueous Solution ◽  
Kinetics And Mechanism ◽  
Mechanism Of The Reaction

Kinetics and mechanism of disproportionation and ferricyanide oxidation of the 10-methylacridinium cation in aqueous base

1984 ◽  
Vol 62 (4) ◽  
pp. 729-735 ◽  
Author(s):  
John W. Bunting ◽  
Glenn M. Kauffman
Keyword(s):  
Ionic Strength ◽  
Second Order ◽  
Kinetics And Mechanism ◽  
Oxidation Pathway ◽  
First Order ◽  
Aqueous Base ◽  
Ph Range ◽  
Rate Profile ◽  
Kinetics Of ◽  
Major Oxidation

The kinetics of disproportionation and ferricyanide ion oxidation of the 10-methylacridinium cation have been measured spectrophotometrically over the pH range 9–14 in.20% CH3CN – 80% H2O (v/v) and ionic strength 1.0 at 25 °C. Disproportionation is kinetically second-order in total acridine species. The pH–rate profile is consistent with the rate-determining reaction of one acridinium cation with the pseudobase alkoxide anion derived from a second acridinium cation. Ferricyanide ion oxidation is kinetically first-order in each of ferricyanide ion and total acridine species. The pH–rate profile requires three distinct pathways for the ferricyanide ion oxidation of the 10-methylacridinium cation. For pH < 9.7, rate-determining attack of ferricyanide ion on the neutral pseudobase predominates, while for pH > 12.8 the predominant oxidation pathway involves reaction of ferricyanide ion with the pseudobase alkoxide ion. Between pH 9.7 and 12.8, the major oxidation pathway involves initial disproportionation of the acridinium cation followed by ferricyanide ion oxidation of the 9,10-dihydro-10-methylacridine product. This latter route accounts for a maximum of 69% of the total ferricyanide ion oxidation at pH 11.1.

Kinetics and Mechanism of the Reaction of a Ruthenium(VI) Nitrido Complex with HSO3 − and SO3 2− in Aqueous Solution

2016 ◽  
Vol 22 (31) ◽  
pp. 10754-10758 ◽  
Author(s):  
Qian Wang ◽  
Hong Yan Zhao ◽  
Wai-Lun Man ◽  
William W. Y. Lam ◽  
Kai-Chung Lau ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Kinetics And Mechanism ◽  
Mechanism Of The Reaction

Kinetics and Mechanism of the Reaction of Dichlorotetraaquaruthenium(III) and Thiols

2012 ◽  
Vol 65 (2) ◽  
pp. 113 ◽  
Author(s):  
Suprava Nayak ◽  
Gouri Sankhar Brahma ◽  
K. Venugopal Reddy
Keyword(s):  
Electron Transfer ◽  
Ionic Strength ◽  
Equilibrium Constants ◽  
Activation Parameters ◽  
Kinetics And Mechanism ◽  
Intermediate Complex ◽  
Mechanism Of Formation ◽  
Temperature Range ◽  
Temperature Reduction ◽  
Mechanism Of The Reaction

The formation of an intermediate ruthenium(iii) thiolate complex by the interaction of thiols, RSH (R = glutathione and l-cysteine) and dichlorotetraaquaruthenium(iii), [RuIIICl2(H2O)4]+, is reported in the temperature range 25–40°C. The kinetics and mechanism of formation of the intermediate complex were studied as a function of [RuIIICl2(H2O)4]+, [RSH], pH, ionic strength and temperature. Reduction of the intermediate complex takes place slowly and results in the corresponding disulfides RSSR and [RuIICl2(H2O)4]+. The results are interpreted in terms of a mechanism involving a rate-determining inner-sphere one-electron transfer from RSH to the oxidant used in the present investigation and a comparison of rate and equilibrium constants is presented with activation parameters.

Kinetics and mechanism of the reaction between the di-μ-cyanobis[tetracyanoferrate(III)] complex ion and sulfite in aqueous solution

2007 ◽  
Vol 360 (7) ◽  
pp. 2284-2290
Author(s):  
Jane Lui-Lym ◽  
Tara P. Dasgupta ◽  
Paul T. Maragh ◽  
Floyd Beckford ◽  
Geoffrey Stedman
Keyword(s):  
Aqueous Solution ◽  
Kinetics And Mechanism ◽  
Complex Ion ◽  
Mechanism Of The Reaction
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