Spin trapping by use of nitroso-compounds. Part V. 2,4,6-Tri-t-butylnitrosobenzene: a new type of spin-trapping reagent

Abstract

The utility of 2,4,6-tri-t-butylnitrosobenzene as a spin-trapping reagent has been examined, and two main advantages of its use have been clarified. 2,4,6-Tri-t-butylnitrosobenzene has two sites for spin trapping. Primary alkyl radicals normally attack the nitrogen atom of the nitroso-group to generate nitroxides. Tertiary alkyl radicals, however, attack the oxygen atom of the nitroso-group to form N-alkoxyanilino-radicals which are sufficiently stable for e.s.r. spectra to be recorded. Secondary alkyl radicals usually add both on the nitrogen and oxygen atoms to produce both the corresponding spin adducts, whose ratio varies with the structure of the radical trapped. Solutions of the nitroso-compound produce no detectable paramagnetic species during u.v. irradiation. The relation between the structure of a spin adduct and the spectral datum is discussed.