After production of I~, however, HOI will carry most of the
oxidation through the rapid equilibrium reaction (M2). Reac-
tions (M9), (M10) and (M11) show the step-wise oxidation of
AETSA to the sulfonic acid and sulfate. For these simulations
it was assumed that the cleavage of the SwS bond occurs
together with a two-electron oxidation of the inner sulfur
atom. Reactions (M12) and (M13) show the oxidation of
AETSA by the molecular iodine species. The rate constant,
ported by a grant from the National Science Foundation
(Grant Number CHEÈ9632592).
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11
3
4
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6
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as a result of the other species which have slight absorptivities
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Conclusion
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Our proposed mechanism is the most concise that can be gen-
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eventually end up in the preferred oxidation states of [2, 0
and ]6. By maintaining HOI as the sole important oxidant in
solution, errors that might arise from omitting sulfurÈsulfur
reactions have been minimized. For example, two sulÐnic acid
centres can disproportionate:
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18 R. J. Field and R. M. Noyes, J. Chem. Phys., 1974, 60, 1877.
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SII ] SII ] SIV ] SO
(19)
2
2
7
8
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2
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between mixing of solution and production of BaSO
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4
3
3
0
1
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The NMR data strongly suggest that the initial step is the
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3
5 P. Kaps and P. Rentrop, Numer. Math., 1979, 23, 55.
We would like to acknowledge helpful discussions with Pro-
fessors Jonnalagadda and Martincigh. This work was sup-
Paper 6/06729H; Received 1st October, 1996
1550
J. Chem. Soc., Faraday T rans., 1997, V ol. 93