$Ru^{III}(edta)$ mediated oxidation of azide in the presence of hydrogen peroxide : azide versus peroxide activation

The [Ru III (edta)(H 2 O)] − (edta 4 − = ethylenediaminetetraacetate) complex catalyzes the oxidation of azide (N 3 − ) with H 2 O 2 , mimicking the action of metallo-enzymes such as catalase and peroxidase in biochemis- try. The kinetics of the catalytic oxidation process was studied by using stopped- fl ow and rapid-scan spectrophotometry as a function of [Ru III (edta)], [H 2 O 2 ], [N 3 − ] and pH. The catalytic activity of the di ff erent oxidizing species produced in the reaction of [Ru III (edta)(H 2 O)] − with H 2 O 2 for the oxidation of azide was compared to the oxidation of coordinated azide in [Ru III (edta)N 3 ] 2 − by H 2 O 2 . Detailed reaction mecha- nisms in agreement with the spectroscopic and kinetic data are presented for both reaction paths.