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Substituent effects on the disproportionation‐combination rate constant ratios for gas‐phase halocarbon radicals. II. Reactions of •CF 3 +CF 3 CH 2 CH 2 • and CF 3 CH 2 CH 2 • + CF 3 CH 2 CH 2 •
Author(s) -
McDowell Derek R.,
Weston Jennie,
Holmes Bert E.
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)28:1<61::aid-kin8>3.0.co;2-k
Subject(s) - chemistry , radical , disproportionation , substituent , reaction rate constant , halocarbon , chlorine , chlorine atom , gas phase , photochemistry , halogen , computational chemistry , medicinal chemistry , organic chemistry , kinetics , catalysis , alkyl , physics , quantum mechanics
Disproportionation/combination rate constant ratios, k d / k c , have been measured for the collision between CF 3 CH 2 CH 2 and CF 3 radicals to be 0.022 ± 0.002 and for CF 3 CH 2 CH 2 and CF 3 CH 2 CH 2 radicals to be 0.100 ± 0.002. Comparison to previous work from this laboratory for the reaction of CF 3 CH 2 CHCl with CF 3 radicals shows that substitution of Cl for H increases the k d / k c by about 50%; however, for the auto disproportionation‐combination of CF 3 CH 2 CH 2 radicals the chlorine substituent decreases the observed rate constant ratio by a factor of two. The chlorine substituent effect on the observed k d / k c ratios is compared to predictions from molecular orbital calculations. © 1996 John Wiley & Sons, Inc.