Ru(III)(edta) mediated oxidation of azide in the presence of hydrogen peroxide. Azide versus peroxide activation.

The [Ru(III)(edta)(H2O)](-) (edta(4-) = ethylenediaminetetraacetate) complex catalyzes the oxidation of azide (N3(-)) with H2O2, mimicking the action of metallo-enzymes such as catalase and peroxidase in biochemistry. The kinetics of the catalytic oxidation process was studied by using stopped-flow and rapid-scan spectrophotometry as a function of [Ru(III)(edta)], [H2O2], [N3(-)] and pH. The catalytic activity of the different oxidizing species produced in the reaction of [Ru(III)(edta)(H2O)](-) with H2O2 for the oxidation of azide was compared to the oxidation of coordinated azide in [Ru(III)(edta)N3](2-) by H2O2. Detailed reaction mechanisms in agreement with the spectroscopic and kinetic data are presented for both reaction paths.