An electron spin resonance study of radicals produced by oxidation of ortho-mono- and -di-hydroxybiphenyls

Abstract

The e.s.r. spectra obtained by oxidation of biphenyl-2,2′-diols in neutral solution showed the formation of a monoaryloxyl radical in which the unpaired electron is shared equally by both rings. In the spectra of radicals from unhindered 2,2′-diols variation of the temperature produced small changes in g value, which appeared to have a periodic character. Hyperfine splitting constants varied with temperature in both hindered and unhindered radicals. Splitting constants were also unambiguously assigned to the spectra obtained from substituted biphenyl-2-ols.