Kinetics of Radiation-Induced Free-Radical Oxidation by Unbranched-Chain Mechanism

“

In such binary reaction systems consisting of a saturated component (hydrocarbon, alcohol, etc.) and an unsaturated one (olefin, allyl alcohol, formaldehyde, or dioxygen), the unsaturated compound (in this case the molecular oxygen) is both a reactant and an autoinhibitor, specifically, a source of low-reactive free radicals (in this case the alkyltetraoxyl RO4 or hydrotetraoxyl HO4 1:2 adduct radicals) shortening kinetic chains. The progressive inhibition of the nonbranched-chain processes, which takes place as the concentration of the unsaturated compound is raised (after the maximum process rate is reached), can be an element of the self-regulation of the natural processes that returns them to the stable steady state. Using mechanism of the nonbranched-chain free-radical hydrogen oxidation considered in this work, it has been demonstrated that, in the Earth’s upper atmosphere, the decomposition of ozone in its reaction with the hydroxyl radical НО• can occur via the addition of the latter to the ozone molecule, yielding the hydrotetraoxyl radical HO4, which is capable of efficiently absorbing UV radiation.

”