Electron Spin Resonance Hyperfine Spectra of Diphenyl Nitric Oxide

Liquid solutions of diphenyl nitric oxide reveal well-resolved proton hyperfine spectra either in mixed solvents of glycerine and ethyl alcohol in a suitable mixed ratio or in vacuum-sealed, degassed solvents. Assuming odd electron spin densities at the ring carbon atoms and applying Kivelson’s theory, one can explain the experimental results. Moreover, the effect on the ESR spectra of the addition of a methyl group to a benzene ring has been reported on. Finally, the solvent effect on the ESR spectra has been discussed.