Nuclear magnetic resonance of organic free radicals

Abstract

The conditions under which N.M.R. spectra of organic free radicals can be observed are discussed. The N.M.R. spectra of several radicals are shown and compared with the E.S.R. spectra of the same radicals. The N.M.R. spectra are particularly useful to determine small coupling constants which are below the limit of resolvability of E.S.R. and ENDOR. Futhermore, N.M.R. renders the sign as well as the magnitude of the interaction between the unpaired electron and the nucleus investigated; it can contribute to the understanding of the mechanism of this interaction.