RATE CONSTANTS FOR THE GAS-PHASE REACTION OF OZONE WITH 1,2-DISUBSTITUTED ALKENES

The gas-phase reaction of ozone with eight 1,2-disubstituted alkenes h as been investigated at ambient temperature (T = 286-296 K) and p = 1 atm. of air. The reaction rate constants, in units of 10(-18) cm(3) mo lecule(-1)s(-1), are 144 +/- 17 for cis-3-hexene, 157 +/- 25 for trans -3-hexene, 89.8 +/- 9.7 for cis-4-octene, 131 +/- 15 for trans-4-octen e, 114 +/- 13 for cis-5-decene, greater than or equal to 130 for trans -5-decene, 38.3 +/- 5.0 for trans-2,5-dimethyl-3-hexene, and 40.3 +/- 6.7 for trans-2,2-dimethyl-3-hexene. Substituent effects on alkene rea ctivity are examined. Cis-1,2-disubstituted alkenes are less reactive than the corresponding trans isomers. The 1,2-disubstituted alkenes th at bear bulky substituents (substitution at the 3-carbon) are ca. 3 ti mes less reactive than the corresponding M-alkyl substituted compounds . The atmospheric persistence of 1,2-disubstituted alkenes is briefly discussed. (C) 1996 John Wiley & Sons, Inc.