The formation of singlet oxygen in the interaction of chlorine dioxide with
ozone in CCl4 was proved and its yield was determined by the IR chemilumin
escence method. The yield of O-1(2) in this reaction strongly depended on t
he ratio between the initial reagent concentrations and might reach 150%. T
his led us to suggest a radical-chain mechanism of the reaction. Possible p
aths of oxygen formation in the reaction were considered.