OSMIUM(VIII)CATALYSED OXIDATION OF ALLYL ALCOHOL BY DIPERIODATONICKELATE(IV)IN AQUEOUS ALKALINE MEDIUM.AKINETIC AND MECHANISTIC STUDY

摘要

The kinetics of osmium(VIII)catalysed oxidation of allyl alcohol by alkaline diperiodatonickelate(IV)(DPN)was studied spectrophotometrically.The reaction is first order with respect to [DPN]and Os(VIII)and is apparently less than unit order each in [allyl alcohol]and [alkali]under the experimental conditions.Addition of periodate has retarding effect on the reaction rate.A mechanism involving the formation of an intermediate complex between the catalyst,osmium(VIII)species and allyl alcohol has been proposed.The progress of the reaction is observed by the two stages,fast stage followed by slow depletion.There is a good agreement between the observed and calculated rate constants under varying experimental conditions.The activation parameters with respect to the slow step of scheme were evaluated and discussed.