THE ELECTROPHILIC TRIFLUOROMETHYL RADICAL CF3 - APPLICATION OF THE DUAL-PARAMETER EQUATION TO THE CORRELATION-ANALYSIS OF RELATIVE RATES OFTHE TRIFLUOROMETHYLBROMO ADDITION-REACTIONS TO 14 P-Y-SUBSTITUTED PHENYLACETYLENES

A rigorous procedure was applied to the measurement of the relative ra tes, i.e., k(r)(Y) = k(Y)/k(H), of the trifluoromethylbromo addition r eactions to 14p-Y-substituted phenylacetylenes (1-Y, with Y = F, Cl, B r, Me, (t)Bu, OMe, SMe, SiMe(3), CF3, CN, NO2, SOMe, COMe and CO(2)Me) . The reaction was run in cyclohexane under nitrogen at 55 +/- 0.5 deg rees C and was initiated by di-t-butylperoxy-oxalate. Correlation anal ysis of the data suggests that a spin effect is also operating at the transition state of this addition reaction and that the dual-parameter equation is applicable to this reaction.