ISSN:
1572-901X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary The kinetics of the OsVIII-catalysed oxidation of glycols by alkaline hexacyanoferrate(III) ion exhibits zerothorder dependence in [Fe(CN) 6 3− ] and first-order dependence in [OsO4]. The order with respect to glycols is less than unity, whereas the rate dependence on [OH−] is a combination of two rate constants; one independent of and the other first-order in [OH−]. These observations are commensurate with a mechanism in which two complexes, [OsO4(H2O)G]− and [OsO4(OH)G]2−, are formed either from [OsO4(H2O)(OH)]− or [OsO4(OH)2]2− and the glycol GH, or by [OsO4(H2O)2] and [OsO4(H2O)(OH)]− and the glycolate ion, G−, which is in equilibrium with the glycol GH through the reaction between GH and OH−. Hence there is an ambiguity about the true path for the formation of the two OsVIII-glycol complexes. A reversal in the reactivity order of glycols in the two rate-determining steps, despite the common attack of OH− ion on the two species of OsVIII-complexes, indicates that the two complexes are structurally different because ΔS
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01127875
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