Fre‐radical addition to olefins, Part 22. Arrhenius parameters for the addition of trifluoromethyl radicals to vinyl monomers (CH₂CHX)

Abstract

Relative Arrhenius parameters have been determined for the addition of trifluoromethyl radicals to vinyl chloride (X=CI), vinyl bromide (X=Br), acrylonitrile (X=CN), methyl vinyl ketone (X=COCH3), Z-methylbut-2-ene, and to iso-butene, taking the rate of addition to ethylene as standard. Addition occurred virtually exclusively a t the unsubstituted end of all the olefins. The relative rates of addition a t 164°C show very little variation. The preexponential terms for addition to the CH2 ends are constant within experimental error, and the small variations in rate are due principally to the activation energy term. The present results are put on an absolute scale using the previously determined Arrhenius parameters for addition to ethylene and are compared with data for other similar monomers determined previously.