The mechanism and kinetics of ozone formation in a pulse radiolysis study of the Ar-O2 system

The mechanism and kinetics of O3 formation after an electron pulse have been studied in the Ar-O2 systems by time resolved optical measurements at λ = 260 nm. The second order rate constant of energy transfer from excited Ar(4s,4p) states to O2 molecules: (1) Ar*,Ar** + O2 → O2* + Ar, was found to be (8.9 ± 2.1)·10-10 cm3.s-1. It was found also the evidence of the third order process contribution to the energy transfer: (2) Ar*,Ar** + Ar + O2 → products, with the rate constant in the range (1.5-3.7)·10-29 cm6.s-1. The rate constant of the deactivation of excited ozone molecules by O2 was found to be (5.1 ± 0.6)·10-15 cm3.s-1. (author)