The kinetics of the addition of alkyl radicals to carbonyl groups. II. The addition of methyl radicals to trifluoroacetone in the gas phase. The formation reaction of the trifluoro-t-butoxy radical
By photolyzing azomethane over the temperature range 331–491 K in the presence of trifluoroacetone the kinetics of the addition reaction (1), ?H3 + CF3COCH3 → CF3C(?)(CH3)2 have been studied. Detailed analyses have shown that the principal product of the adduct radical, CF3C(?)(CH3)2, is CH3COCH3 from reaction (?2), CF3C(?)(CH3)2 → CH3COCH3 + ?F3. The rate constant of the addition reaction has been determined to be k1(dm3/mol s) = (4.5 ± 1.4) × 107 exp(-(3370 ± 120)/T) over the temperature range 331–491 K, based on the value k3 = 2.2 × 1010 dm3/mol s for the reaction (3), 2?H3 → C2H6. The results are discussed in relation to existing data for radical additions to groups.
