Ruthenium (III) catalysis of periodate oxidation of reducing sugars in aqueous alkaline medium

Abstract

The ruthenium (TU) catalysis of periodate oxidation of D-ribose, D-sorbose and maltose in aqueous alkaline medium has been investigated. The reactions have been found to be zero order with respect to each reducing sugar and first order with respect to ruthenium (III). The linear dependence of the reaction rate at lower concentrations of periodate ion and hydroxide ion tends towards zero order at their higher concentrations. Positive effect of [Cl¯] on the rate of reaction has also been observed. The observed kinetics with periodate ion, under the conditions [IO<img src='http://www.niscair.res.in/jinfo/Subscript4.gif' border=0>] > >[Ru(III)]_T suggests the formation of a 1:1 complex between Ru(III) and periodate in the rate controlling step, which subsequently interacts with reactive species of reducing sugar to give the final products, through a series of fast steps. The rate law is derived.