Electron spin resonance studies of spin trapping. On the role of hydroxylamines and an oxaziridine in the formation of nitroxides following addition of hydroxyalkyl radicals to N-t-butyl-α-phenylnitrone

Abstract

E.s.r. experiments demonstrate that when α-hydroxyalkyl radicals ·CR¹R²OH are generated photochemically in the presence of the nitrone PhCHN⁺(Bu^t)O^– the resulting adducts PhCH(CR¹R²OH)N(Bu^t)O· are photochemically labile but build up with time when irradiation is interrupted. The latter unusual observation is interpreted in terms of the oxidation of the intermediate hydroxylamine (generated by photolysis of the nitroxide) by the oxaziridine, Ph[graphic omitted], which results from photolysis of thet rap. These findings, and the results obtained when oxygen is admitted, point to the need for caution in interpreting results from spin-trapping experiments.