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

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.

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An attenuated total internal reflection spectroscopy study of the kinetics of metal ion extraction at the decane-aqueous solution interface

Langmuir ◽

10.1021/la00038a007 ◽

1992 ◽

Vol 8 (2) ◽

pp. 366-368 ◽

Cited By ~ 19

Author(s):

Jilska M. Perera ◽

Jennifer K. McCulloch ◽

Brent S. Murray ◽

Franz Grieser ◽

Geoffrey W. Stevens

Keyword(s):

Aqueous Solution ◽

Total Internal Reflection ◽

Metal Ion ◽

Spectroscopy Study ◽

Reflection Spectroscopy ◽

Metal Ion Extraction ◽

Ion Extraction ◽

Solution Interface ◽

Internal Reflection Spectroscopy ◽

Kinetics Of

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Laboratory-scale photomineralisation of n-alkanes in aqueous solution, by photocatalytic membranes immobilising titanium dioxide

International Journal of Photoenergy ◽

10.1155/s1110662x05000127 ◽

2005 ◽

Vol 7 (2) ◽

pp. 79-85 ◽

Cited By ~ 14

Author(s):

Ignazio Renato Bellobono ◽

Franca Morazzoni ◽

Riccardo Bianchi ◽

Emilia Simona Mangone ◽

Rodica Stanescu ◽

...

Keyword(s):

Aqueous Solution ◽

Photocatalytic Oxidation ◽

Point Of View ◽

Laboratory Scale ◽

Kinetic Constants ◽

Quantum Yields ◽

Oxidation Of Methane ◽

Oxygen Donor ◽

Absorbed Power ◽

Kinetics Of

Kinetics of photocatalytic oxidation of methane, ethane,n-heptane,n-decane, andn-dodecane, to yield intermediates, and photomineralisation of intermediates, to yield carbon dioxide and water, was studied in aqueous solution, by a laboratory-scale photoreactor and photocatalytic membranes immobilizing30±3wt.% ofTiO2, in the presence of stoichiometric hydrogen peroxide as oxygen donor. The whole volume of irradiated solution was4.000±0.005L, the ratio between this volume and the geometrical apparent surface of the irradiated side of the photocatalytic membrane was3.8±0.1cm, and the absorbed power 0.30W/cm (cylindrical geometry). A kinetic model was used, by which mineralisation of substrate toCO2was supposed to occur, by kinetic constantsk1, through one single intermediate, mediating the behaviour of all the numerous real intermediates formed in the path from the substrate toCO2(kinetic constants of formation of the latter beingk2). A competitive Langmuirian adsorption of both substrate and “intermediate” was also supposed to be operative, as expressed by apparent adsorption constantsk1andk2, possessing a, partly at least, kinetic significance. By Langmuir-Hinshelwood treatment of initial rate data, starting values of thekandKcouples were obtained, from which, by a set of differential equations, the final optimised parameters,k1andk1,k2andK2, were calculated, able fit the whole photomineralisation curve, and not only its initial segment, as the Langmuirian parameters do. The parameters of present work are critically compared with those obtained in two preceding set of studies relative ton-alkanoic acids and ton-alkanols. They are interpreted on the basis of a closer behaviour of hydrocarbons to alkanols, from the photocatalytic point of view, than to carboxylic acids are. Discussion of limiting effective quantum yields, and their comparison with maximum, theoretical values, are also carried out.

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

Inorganic Chemistry ◽

10.1021/ic00246a010 ◽

1986 ◽

Vol 25 (26) ◽

pp. 4639-4642 ◽

Cited By ~ 24

Author(s):

Johann G. Leipoldt ◽

Rudi Van Eldik ◽

Stephen S. Basson ◽

Andreas Roodt

Keyword(s):

Aqueous Solution ◽

Kinetics And Mechanism ◽

Mechanism Of The Reaction

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CATALYTIC ACTIVATION OF HYDROGEN IN AQUEOUS SOLUTION BY THE CHLOROPALLADATE(II) ION

Canadian Journal of Chemistry ◽

10.1139/v59-212 ◽

1959 ◽

Vol 37 (9) ◽

pp. 1446-1450 ◽

Cited By ~ 13

Author(s):

J. Halpern ◽

J. F. Harrod ◽

P. E. Potter

Keyword(s):

Aqueous Solution ◽

Ferric Chloride ◽

Molecular Hydrogen ◽

Homogeneous Catalyst ◽

Rate Law ◽

Catalytic Activation ◽

Kinetics Of ◽

Mechanism Of The Reaction

The kinetics of the reduction of ferric chloride by molecular hydrogen in aqueous solution, in the presence of chloropalladate(II), were examined. The latter acts as a homogeneous catalyst for the reaction. The rate-law was found to be,[Formula: see text]where[Formula: see text]The mechanism of the reaction is discussed.

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