Abstract: | Disproportionation/combination rate constant ratios, kd /kc, have been measured for the collision between CF3CH2CH2 and CF3 radicals to be 0.022 ± 0.002 and for CF3CH2CH2 and CF3CH2CH2 radicals to be 0.100 ± 0.002. Comparison to previous work from this laboratory for the reaction of CF3CH2CHCl with CF3 radicals shows that substitution of Cl for H increases the kd /kc by about 50%; however, for the auto disproportionation-combination of CF3CH2CH2 radicals the chlorine substituent decreases the observed rate constant ratio by a factor of two. The chlorine substituent effect on the observed kd /kc ratios is compared to predictions from molecular orbital calculations. © 1996 John Wiley & Sons, Inc. |