New access to the peroxyl radicals reactivity?

A new procedure for the direct study of the chemical reactivity of peroxyl radicals ( R–O 2 ) is used. The particular TEA–O 2 radical (where TEA is the triethylamine moiety), directly observed by laser flash photolysis, is characterized by a strongly red shifted transition in the near visible wavelength range. This provides an original access to the interaction rate constants of TEA–O 2 with different additives (hydrogen donating compounds, electron acceptors, triphenylphosphine). Rate constants of hydrogen abstraction range from 1.9 × 102 to 1.1 × 106 M−1 s−1 for TEA–O 2 and roughly appear as governed in several systems by the reaction exothermicity. The interactions with triphenylphosphine are discussed.