Ozone–olefin reactions in the gas phase 1. Rate constants and activation energies

Reactions of ozone with simple olefins have been studied between 6 and 800 mtorr total pressure in a 220‐m 3 reactor. Rate constants for the removal of ozone by an excess of olefin in the presence of 150 mtorr oxygen were determined over the temperature range 280 to 360° K by continuous optical absorption measurements at 2537 Å. The technique was tested by measuring the rate constants k 1 and k 2 of the reactions (1) NO + O 3 → NO 2 + O 2 and (2) NO 2 + O 3 rarr; NO 3 + O 2 which are known from the literature. The results for NO, NO 2 , C 2 H 4 , C 3 H 6 , 2‐butene (mixture of the isomers), 1,3→butadiene, isobutene, and 1,1 ‐difluoro‐ethylene are 1.7 × 10 −1 4 (290°K), 3.24 × 10 −17 (289°K), 1.2 × 10 −1 4 exp (–4.95 ± 0.20/ RT ), 1.1 × 10 −1 4 exp (–3.91 ± 0.20/ RT ), 0.94 × 10 −1 4 exp ( –2.28 ± 0.15/ RT ), 5.45 ± 10 −1 4 exp ( –5.33 ± 0.20/ RT ), 1.8 ×10 −17 (283°K), and 8 × 10 −20 cm 3 /molecule ·s(290°K). Productformation from the ozone–propylene reaction was studied by a mass spectrometric technique. The stoichiometry of the reaction is near unity in the presence of molecular oxygen.