FIRST DIRECT KINETIC-STUDY OF ISOTOPIC ENRICHMENT OF OZONE

The formation kinetics of ozone has been studied using isotopes and pu lse 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 isot opic ozone. The results are compared with recent enhancement studies f rom the literature, and an apparent conflict is discussed.