Kinetics and mechanism of the stoichiometric oxidation of toluene and benzyl alcohol by [Ru^v=O(EDTA)]⁻ and [Ru^v=O(PDTA)]⁻ complexes in water-dioxan medium

Abstract

Stoichiometric oxidations of toluene to benzyl alcohol and benzyl alcohol to benzaldehyde with LRu^v=O⁻ (L=EDTA, PDTA) were studied spectrophotometrically at constant pH=5.0 and ionic strength of 0.1 M (NaClO₄). The reaction rate is first order with respect to oxo complex. Increasing the substrate (toluene, benzyl alcohol) concentration increases the reaction rate, and at high substrate concentration the reaction rate is independent of substrate concentration. The rate of oxidation of benzyl alcohol by LRu^v=O⁻ complexes was found to be five times that of toluene. The oxidations of toluene to benzyl alcohol and benzyl alcohol to benzaldehyde by LRu^v=O⁻ were studied at three different temperatures and the rate and activation parameters determined. A suitable mechanism consistent with the experimental results has been proposed.