Premium
Rate constants for the gas‐phase reaction of ozone with 1, 1‐disubstituted alkenes
Author(s) -
Grosjean Eric,
Grosjean Daniel
Publication year - 1996
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/(sici)1097-4601(1996)28:12<911::aid-kin8>3.0.co;2-q
Subject(s) - chemistry , isoprene , alkene , reactivity (psychology) , steric effects , substituent , medicinal chemistry , reaction rate constant , isopropyl , ozone , butane , photochemistry , butene , ethylene , organic chemistry , kinetics , catalysis , physics , quantum mechanics , medicine , polymer , alternative medicine , pathology , copolymer
Abstract The gas‐phase reaction of ozone with eight alkenes including six 1,1‐disubstituted alkenes has been investigated at ambient T (285–298 K) and p = 1 atm. of air. The reaction rate constants are, in units of 10 −18 cm 3 molecule −1 s −1 , 9.50 ± 1.23 for 3‐methyl‐1‐butane, 13.1. ± 1.8 for 2‐methyl‐1‐pentene, 11.3 ± 3.2 for 2‐methyl‐1,3‐butadiene (isoprene), 7.75 ± 1.08 for 2,3,3‐trimethyl‐1‐butene, 3.02 ± 0.52 for 3‐methyl‐2‐isopropyl‐1‐butene, 3.98 ± 0.43 for 3,4‐diethyl‐2‐hexene, 1.39 ± 17 for 2,4,4‐trimethyl‐2‐pentene, and >370 for ( cis + trans )‐3,4‐dimethyl‐3‐hexene. For isoprene, results from this study and earlier literature data are consistent with: k (cm 3 molecule −1 s −1 ) = 5.59 (+ 3.51, &minus 2.16) × 10 −15 e (−3606±279/RT) , n = 28, and R = 0.930. The reactivity of the other alkenes, six of which have not been studied before, is discussed in terms of alkyl substituent inductive and steric effects. For alkenes (except 1,1‐disubstituted alkenes) that bear H, CH 3 , and C 2 H 5 substituents, reactivity towards ozone is related to the alkene ionization potential: In k <(10 −18 cm 3 molecule −1 s −1 ) = (32.89 ± 1.84) − (3.09 ± 0.20) IP (eV), n = 12, and R = 0.979. This relationship overpredicts the reactivity of C ≥3 1‐alkenes, of 1,1‐disubstituted alkenes, and of alkenes with bulky substituents, for which reactivity towards ozone is lower due to substituent steric effects. The atmospheric persistence of the alkenes studied is briefly discussed. © 1996 John Wiley & Sons, Inc.