Free-radical addition to olefins. Part 26.—Kinetics of the addition of trifluoromethyl radicals to acetylene and substituted acetylenes

Abstract

Absolute Arrhenius parameters have been determined for the addition of trifluoromethyl radicals to acetylene, propyne, but-2-yne, 1,1,1-trifluoropropyne and hexafluorobut-2-yne by a competitive method using the previously determined Arrhenius parameters for the addition of trifluoromethyl radicals to ethylene as standard.

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Both the activation energies and the A-factors are larger than those for the addition of trifluoromethyl radicals to similarly substituted olefins. As a result of these opposing effects the rates of addition are similar.