Kinetics of Ru(III) and Mn(II) catalysed oxidation of arenes by lead tetraacetate

Kinetics of acetoxylation of toluene, m-xylene, p-xylene and p-toluenesulphonic acid in 100% acetic acid with sodium acetate (0.02 to 0.08 mol dm(-3)) in the presence of Ru(III) catalyst (1.9 x 10(-5) to 7.6 x 10(-5) mol dm(-3)) has been reported. The reactions are first order in hydrocarbon, in Ru(III) and zero order in lead tetraacetate (LTA). Addition of small percent of water has a marginal effect on the reaction rate. Increase of sodium acetate has no effect on the reaction rates. Increase in [H+] leads to an increase of the rate in all cases with a positive slope of 0.5. Mn(II) catalysed oxidation reaction shows a different trend, the kinetic orders being first order in Mn(II), zero order in both LTA and substrates. p-a Plot shows a breakdown of structure-activity relationships. A suitable mechanism with rate law has been postulated.