ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of oxygen exchange between water (H2O, D2O) and 18O-labelled bromate ion has been investigated over the range of 1.7 ≤ pH ≤ 14.3 and 20 ≤ °C ≤ 95. At 60° and ionic strength I ≃ 1.0M (NaNO3), the experimental results were consistent with the rate laws (R in moll-1 s-1): \documentclass{article}\pagestyle{empty}\begin{document}$$ R = [{\rm BrO}_{\rm 3} ^ -]\{ 1.59 \cdot 10^{ - 6} + 8.1 \cdot 10^{ - 7} [{\rm OH}^ -] + 0.122[{\rm H}^ +]^2 \} \,{\rm in}\,{\rm H}_{\rm 2} {\rm O}\,{\rm and} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ R = [{\rm BrO}_{\rm 3} ^ -]\{ 4.69 \cdot 10^{ - 7} + 4.1 \cdot 10^{ - 7} [{\rm OD}^ -] + 0.378[{\rm D}^ +]^2 \} \,{\rm in}\,{\rm D}_{\rm 2} {\rm O}. $$\end{document}From the temperature dependence of the rate constants the activation parameters ΔH≠, ΔS≠ and ΔC≠ were derived.In the acid-catalysed region the form of the rate law and the direction of the solvent isotope effect were the same as previously found, but the numerical values of ΔH≠ and k2H/k2D differ considerably. For the spontaneous and the OH--catalysed exchange reactions bimolecular displacement mechanisms are proposed.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19720550306
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