Kinetics and Mechanism for the Redox Reaction between Hexaaquathallium(III) and Sulfur Dioxide in Acidic Aqueous Solution

Berglund, Johan; Werndrup, Pia; Elding, Lars Ivar

Kinetics and Mechanism for the Redox Reaction between Hexaaquathallium(III) and Sulfur Dioxide in Acidic Aqueous Solution

Mark

Berglund, Johan ; Werndrup, Pia and Elding, Lars Ivar ^LU (1994) In Journal of the Chemical Society. Dalton Transactions 1994(9). p.1435-1439

Abstract: Oxidation of dissolved sulfur dioxide, SO2·nH2O, HSO3– and SO32–, by hexaaquathallium(III) has been studied in acidic aqueous solution with ionic strength 1.0 mol dm–3 at 25 °C. The stoichiometry of the reaction has been determined: [Tl(H2O)6]3++ SO2(aq)+ 2H2O →[Tl(H2O)6]++ HSO4–+ 3H+. The kinetics has been studied by use of stopped-flow spectrophotometry under pseudo-first-order conditions with either SIV or TlIII in excess. The reaction is first order in both [SIV] and [TlIII] and has a complex [H+] dependence. The rate decreases with increasing [H+] in the range 0.1 < [H+] < 1.0 mol dm–3. The results are interpreted in terms of a reaction mechanism where sulfito complexes are formed by reaction between [Tl(H2O)6]3+ or... (More); Oxidation of dissolved sulfur dioxide, SO2·nH2O, HSO3– and SO32–, by hexaaquathallium(III) has been studied in acidic aqueous solution with ionic strength 1.0 mol dm–3 at 25 °C. The stoichiometry of the reaction has been determined: [Tl(H2O)6]3++ SO2(aq)+ 2H2O →[Tl(H2O)6]++ HSO4–+ 3H+. The kinetics has been studied by use of stopped-flow spectrophotometry under pseudo-first-order conditions with either SIV or TlIII in excess. The reaction is first order in both [SIV] and [TlIII] and has a complex [H+] dependence. The rate decreases with increasing [H+] in the range 0.1 < [H+] < 1.0 mol dm–3. The results are interpreted in terms of a reaction mechanism where sulfito complexes are formed by reaction between [Tl(H2O)6]3+ or [Tl(H2O)5(OH)]2+ and HSO3–. These complexes decompose to the products [Tl(H2O)6]+ and HSO4– by intramolecular inner-sphere electron-transfer processes. The thallium(III) sulfito complexes are weak, as indicated by the absence of any transient absorbance peaks in the UV region. Potentiometric measurements of the oxygen concentration and spectrophotometric measurements showed that TlIII does not initiate a free-radical chain oxidation of SIV by dissolved oxygen. (Less)
Abstract (Swedish): Oxidation of dissolved sulfur dioxide, SO2·nH2O, HSO3– and SO32–, by hexaaquathallium(III) has been studied in acidic aqueous solution with ionic strength 1.0 mol dm–3 at 25 °C. The stoichiometry of the reaction has been determined: [Tl(H2O)6]3++ SO2(aq)+ 2H2O →[Tl(H2O)6]++ HSO4–+ 3H+. The kinetics has been studied by use of stopped-flow spectrophotometry under pseudo-first-order conditions with either SIV or TlIII in excess. The reaction is first order in both [SIV] and [TlIII] and has a complex [H+] dependence. The rate decreases with increasing [H+] in the range 0.1 < [H+] < 1.0 mol dm–3. The results are interpreted in terms of a reaction mechanism where sulfito complexes are formed by reaction between [Tl(H2O)6]3+ or... (More); Oxidation of dissolved sulfur dioxide, SO2·nH2O, HSO3– and SO32–, by hexaaquathallium(III) has been studied in acidic aqueous solution with ionic strength 1.0 mol dm–3 at 25 °C. The stoichiometry of the reaction has been determined: [Tl(H2O)6]3++ SO2(aq)+ 2H2O →[Tl(H2O)6]++ HSO4–+ 3H+. The kinetics has been studied by use of stopped-flow spectrophotometry under pseudo-first-order conditions with either SIV or TlIII in excess. The reaction is first order in both [SIV] and [TlIII] and has a complex [H+] dependence. The rate decreases with increasing [H+] in the range 0.1 < [H+] < 1.0 mol dm–3. The results are interpreted in terms of a reaction mechanism where sulfito complexes are formed by reaction between [Tl(H2O)6]3+ or [Tl(H2O)5(OH)]2+ and HSO3–. These complexes decompose to the products [Tl(H2O)6]+ and HSO4– by intramolecular inner-sphere electron-transfer processes. The thallium(III) sulfito complexes are weak, as indicated by the absence of any transient absorbance peaks in the UV region. Potentiometric measurements of the oxygen concentration and spectrophotometric measurements showed that TlIII does not initiate a free-radical chain oxidation of SIV by dissolved oxygen. (Less)

Please use this url to cite or link to this publication: https://lup.lub.lu.se/record/8c266fe3-382b-4df2-8d42-8e909f001cb4

author

Berglund, Johan ; Werndrup, Pia and Elding, Lars Ivar ^LU

organization

Centre for Analysis and Synthesis

publishing date

1994-05-07

type

Contribution to journal

publication status

published

subject

Inorganic Chemistry

keywords

Thallium(III), Sulfur dioxide, Redox reaction, Kinetics, Stopped-flow, Reaction mechanism

in

Journal of the Chemical Society. Dalton Transactions

volume

1994

issue

9

article number

4/00063C

pages

1435 - 1439

publisher

Royal Society of Chemistry

external identifiers

scopus:37049070095

ISSN

1472-7773

DOI

10.1039/dt9940001435

language

English

LU publication?

yes

id

8c266fe3-382b-4df2-8d42-8e909f001cb4

date added to LUP

2017-01-07 20:55:10

date last changed

2021-09-12 04:01:35

@article{8c266fe3-382b-4df2-8d42-8e909f001cb4,
  abstract     = {{Oxidation of dissolved sulfur dioxide, SO2·nH2O, HSO3– and SO32–, by hexaaquathallium(III) has been studied in acidic aqueous solution with ionic strength 1.0 mol dm–3 at 25 °C. The stoichiometry of the reaction has been determined: [Tl(H2O)6]3++ SO2(aq)+ 2H2O →[Tl(H2O)6]++ HSO4–+ 3H+. The kinetics has been studied by use of stopped-flow spectrophotometry under pseudo-first-order conditions with either SIV or TlIII in excess. The reaction is first order in both [SIV] and [TlIII] and has a complex [H+] dependence. The rate decreases with increasing [H+] in the range 0.1 &lt; [H+] &lt; 1.0 mol dm–3. The results are interpreted in terms of a reaction mechanism where sulfito complexes are formed by reaction between [Tl(H2O)6]3+ or [Tl(H2O)5(OH)]2+ and HSO3–. These complexes decompose to the products [Tl(H2O)6]+ and HSO4– by intramolecular inner-sphere electron-transfer processes. The thallium(III) sulfito complexes are weak, as indicated by the absence of any transient absorbance peaks in the UV region. Potentiometric measurements of the oxygen concentration and spectrophotometric measurements showed that TlIII does not initiate a free-radical chain oxidation of SIV by dissolved oxygen.}},
  author       = {{Berglund, Johan and Werndrup, Pia and Elding, Lars Ivar}},
  issn         = {{1472-7773}},
  keywords     = {{Thallium(III); Sulfur dioxide; Redox reaction; Kinetics; Stopped-flow; Reaction mechanism}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{9}},
  pages        = {{1435--1439}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Journal of the Chemical Society. Dalton Transactions}},
  title        = {{Kinetics and Mechanism for the Redox Reaction between Hexaaquathallium(III) and Sulfur Dioxide in Acidic Aqueous Solution}},
  url          = {{http://dx.doi.org/10.1039/dt9940001435}},
  doi          = {{10.1039/dt9940001435}},
  volume       = {{1994}},
  year         = {{1994}},
}

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Kinetics and Mechanism for the Redox Reaction between Hexaaquathallium(III) and Sulfur Dioxide in Acidic Aqueous Solution