The electron spin resonance spectra of some hydroxylamine free radicals. Part II. Radicals formed in acid solution from hydroxamic acids

Abstract

The oxidation of hydroxamic acids, R·CO·NH·OH, by ceric sulphate has been studied by e.s.r. spectrometry using the flow method. Two geometrically isomeric sets of radicals are simultaneously formed [graphic omitted]and [graphic omitted] except when R is a very bulky group. The hyperfine splitting constants a_N and a_N–H vary consistently with the polar nature of R in the sense that both decrease as R becomes increasingly electrophilic.