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Reaction of Peroxomonosulfate Radical with Manganese(II) in Acidic Aqueous Solution. A Pulse Radiolysis Study

Berglund, Johan; Elding, Lars Ivar LU ; Buxton, G.V.; McGowan, S. and Salmon, G. A. (1994) In Journal of the Chemical Society - Faraday Transactions 90(21). p.3309-3313
Abstract (Swedish)
The reaction between the SO5– radical and MnII has been proposed to be the most important process for regeneration of MnIII in the MnIII/II-catalysed autoxidation of SIV in acidic aqueous solution. In the present study, the second-order rate constant for this reaction has been determined at pH 3. 0 and 10 mmol dm–3 ionic strength by use of pulse radiolysis. The study was performed in the presence of excess SIV. Under these conditions MnII is distributed among the complexes Mn2+(aq), [Mn(HSO3)]+ and [Mn(SO3)Mn]2+. The rate of reaction decreases as a function of increasing [MnII]total which is rationalized qualitatively by a mechanism involving three parallel reactions between SO5– and the MnII complexes, with rate constants k16, k17 and... (More)
The reaction between the SO5– radical and MnII has been proposed to be the most important process for regeneration of MnIII in the MnIII/II-catalysed autoxidation of SIV in acidic aqueous solution. In the present study, the second-order rate constant for this reaction has been determined at pH 3. 0 and 10 mmol dm–3 ionic strength by use of pulse radiolysis. The study was performed in the presence of excess SIV. Under these conditions MnII is distributed among the complexes Mn2+(aq), [Mn(HSO3)]+ and [Mn(SO3)Mn]2+. The rate of reaction decreases as a function of increasing [MnII]total which is rationalized qualitatively by a mechanism involving three parallel reactions between SO5– and the MnII complexes, with rate constants k16, k17 and k18, respectively.
Mn2++ SO5– [graphic omitted] Mn3++ HSO5–(16), [Mn(HSO3)]++ SO5– [graphic omitted] [Mn(HSO3)]2+ HSO5–(17), [Mn(SO3)Mn]2++ SO5– [graphic omitted] [Mn(SO3)Mn]3++ HSO5–(18), For increasing total concentrations of MnII, formation of the sulfito-bridged complex is favoured which implies that k18 < k16, k17. Values of the second-order rate constant in the range 2 × 10 108–2 × 1010 dm3 mol–1 s–1 have been determined, depending on which MnII species is predominant. Subsequent slow processes are observed following the formation of MnIII. These reactions have been attributed to the disproportionation of MnIII and reactions between the MnIII species and excess SIV. The implications of the present results for the MnIII/II catalysed autoxidation of SIV are discussed. (Less)
Abstract
The reaction between the SO5– radical and MnII has been proposed to be the most important process for regeneration of MnIII in the MnIII/II-catalysed autoxidation of SIV in acidic aqueous solution. In the present study, the second-order rate constant for this reaction has been determined at pH 3. 0 and 10 mmol dm–3 ionic strength by use of pulse radiolysis. The study was performed in the presence of excess SIV. Under these conditions MnII is distributed among the complexes Mn2+(aq), [Mn(HSO3)]+ and [Mn(SO3)Mn]2+. The rate of reaction decreases as a function of increasing [MnII]total which is rationalized qualitatively by a mechanism involving three parallel reactions between SO5– and the MnII complexes, with rate constants k16, k17 and... (More)
The reaction between the SO5– radical and MnII has been proposed to be the most important process for regeneration of MnIII in the MnIII/II-catalysed autoxidation of SIV in acidic aqueous solution. In the present study, the second-order rate constant for this reaction has been determined at pH 3. 0 and 10 mmol dm–3 ionic strength by use of pulse radiolysis. The study was performed in the presence of excess SIV. Under these conditions MnII is distributed among the complexes Mn2+(aq), [Mn(HSO3)]+ and [Mn(SO3)Mn]2+. The rate of reaction decreases as a function of increasing [MnII]total which is rationalized qualitatively by a mechanism involving three parallel reactions between SO5– and the MnII complexes, with rate constants k16, k17 and k18, respectively.

Mn2++ SO5– [graphic omitted] Mn3++ HSO5–(16), [Mn(HSO3)]++ SO5– [graphic omitted] [Mn(HSO3)]2+ HSO5–(17), [Mn(SO3)Mn]2++ SO5– [graphic omitted] [Mn(SO3)Mn]3++ HSO5–(18), For increasing total concentrations of MnII, formation of the sulfito-bridged complex is favoured which implies that k18 < k16, k17. Values of the second-order rate constant in the range 2 × 10 108–2 × 1010 dm3 mol–1 s–1 have been determined, depending on which MnII species is predominant. Subsequent slow processes are observed following the formation of MnIII. These reactions have been attributed to the disproportionation of MnIII and reactions between the MnIII species and excess SIV. The implications of the present results for the MnIII/II catalysed autoxidation of SIV are discussed. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Peroxomonosulfate, Manganese(II), Pulse Radiolysis, Autoxidation of sulfur(IV), Catalysis, Reaction mechanism, Fast kinetics
in
Journal of the Chemical Society - Faraday Transactions
volume
90
issue
21
pages
5 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:0001451956
ISSN
0956-5000
DOI
10.1039/ft9949003309
language
English
LU publication?
yes
id
5f0784f7-c030-47c1-9cfe-5c62a9871b9a
date added to LUP
2017-01-07 17:55:07
date last changed
2017-07-13 09:01:26
@article{5f0784f7-c030-47c1-9cfe-5c62a9871b9a,
  abstract     = {The reaction between the SO5– radical and MnII has been proposed to be the most important process for regeneration of MnIII in the MnIII/II-catalysed autoxidation of SIV in acidic aqueous solution. In the present study, the second-order rate constant for this reaction has been determined at pH 3. 0 and 10 mmol dm–3 ionic strength by use of pulse radiolysis. The study was performed in the presence of excess SIV. Under these conditions MnII is distributed among the complexes Mn2+(aq), [Mn(HSO3)]+ and [Mn(SO3)Mn]2+. The rate of reaction decreases as a function of increasing [MnII]total which is rationalized qualitatively by a mechanism involving three parallel reactions between SO5– and the MnII complexes, with rate constants k16, k17 and k18, respectively.<br>
<br>
Mn2++ SO5– [graphic omitted] Mn3++ HSO5–(16), [Mn(HSO3)]++ SO5– [graphic omitted] [Mn(HSO3)]2+ HSO5–(17), [Mn(SO3)Mn]2++ SO5– [graphic omitted] [Mn(SO3)Mn]3++ HSO5–(18), For increasing total concentrations of MnII, formation of the sulfito-bridged complex is favoured which implies that k18 &lt; k16, k17. Values of the second-order rate constant in the range 2 × 10 108–2 × 1010 dm3 mol–1 s–1 have been determined, depending on which MnII species is predominant. Subsequent slow processes are observed following the formation of MnIII. These reactions have been attributed to the disproportionation of MnIII and reactions between the MnIII species and excess SIV. The implications of the present results for the MnIII/II catalysed autoxidation of SIV are discussed.},
  articleno    = {4/01866D},
  author       = {Berglund, Johan and Elding, Lars Ivar and Buxton, G.V. and McGowan, S. and Salmon, G. A. },
  issn         = {0956-5000},
  keyword      = {Peroxomonosulfate,Manganese(II),Pulse Radiolysis,Autoxidation of sulfur(IV),Catalysis,Reaction mechanism,Fast kinetics},
  language     = {eng},
  month        = {11},
  number       = {21},
  pages        = {3309--3313},
  publisher    = {Royal Society of Chemistry},
  series       = {Journal of the Chemical Society - Faraday Transactions},
  title        = {Reaction of Peroxomonosulfate Radical with Manganese(II) in Acidic Aqueous Solution. A Pulse Radiolysis Study},
  url          = {http://dx.doi.org/10.1039/ft9949003309},
  volume       = {90},
  year         = {1994},
}