ESR study of the free radicals formed in the photolysis of ?-ketofluorosulfates

Abstract

ESR spectroscopy was used to establish that the UV irradiation of α-ketofluorosulfates containing an OSO 2 F group at a tertiary carbon atom gives radicals formed upon cleavage of the C-OSO 2 F bond. If the OSO 2 F group is attached to a primary or secondary carbon atom, we observe ordinary photodecomposition with cleavage of the acyl—carbon bond. The ESR spectra of the new radicals were studied. Replacement of fluorine by the OSO 2 F group in the trifluoromethyl radical leads to compression of the radical site. Branched α-oxoperfluoroalkyl radicals are not heteroallylic and the unpaired electron is localized largely on the carbon atom. The [(CF 3 ) 2 CF] 2 ĊC(O)CF 3 radical is stable in the air.