FIRST DIRECT KINETIC-STUDY OF ISOTOPIC ENRICHMENT OF OZONE

The formation kinetics of ozone has been studied using isotopes and pulse radiolysis combined with time-resolved UV absorption spectroscopy.;An enhancement of (9.8 +/- 2.6)% was found for the rate constant for the reaction of O-18 with (OO)-O-18-O-18 relative to that for the O-16 + (OO)-O-16-O-16 reaction. The average formation rate for unsymmetric (OOO)-O-18-O-16-O-16 and (OOO)-O-16-O-18-O-18 from O-2, and (OO)-O-18-O-18 respectively was enhanced by (14.7 +/- 2.8)%. For the formation of a mixture of symmetric and unsymmetric ozone species from (OO)-O-18 the enhancement was (3.6 +/- 2.4)%. This leads to the conclusion that both mass and symmetry affect the rate constant for formation of isotopic ozone. The results are compared with recent enhancement studies from the literature, and an apparent conflict is discussed.