ESR STUDY OF FREE-RADICALS FORMED UPON UV IRRADIATION OF NITROPENTAFLUOROACETONE IN VARIOUS SOLVENTS

The formation of CF3C(O)CF2N(O.)O2CF2C(O)CF3 free radicals upon the UV irradiation of nitropentafluoroacetone (1) in toluene and mesitylene is established by ESR. The most likely cause of their formation is the one-electron oxidation of the solvents by photoexcited 1 followed by decay of the radical anion formed from 1 with the expulsion of an NO2 anion and attachment of the radical to a molecule of original 1. The i rradiation of 1 in triethylsilane results in the elimination of a fluo ride ion and fixation of a CF3COCFN(O-)O. radical. UV irradiation of k etone 1 in pentane results in the abstraction of a hydrogen atom from the solvent and the formation of a CF3COCF2N(OH)O. radical.