Chlorine Hyperfine Splittings in Phenoxy Free Radicals

Abstract

HOLLOCHER ^{et al.1} have presented evidence for chlorine hyperfine splittings of the electron spin resonance spectrum of 2-hydroxy-l,4-naphthosemiquinone chloro-derivatives. The observed splitting was quite small (0.28 gauss) and no attempt was made to present a value for a chlorine splitting constant. In order to obtain a larger splitting from the chlorine nuclear spin and perhaps also to obtain an estimate of the splitting constant, an electron spin resonance investigation of the chloroderivatives of phenoxy radicals was made. The electron spin resonance spectrum of the unsubstituted phenoxy radical has been obtained by Stone and Waters², using a flow apparatus³ in order to detect this short-lived free radical. The electron spin resonance spectra of the free radicals of phenol, p-chlorophenol, 2,6-dichlorophenol and 2,4-dichlorophenol have been detected using a similar system and are reported here.