Electrochemical Oxidation of Nitrosobenzene and Derivatives in Organic Medium. Electron Spin Resonance of the Cation—Radicals

The ESR spectra of the radical cations of nitrosobenzene, 2,4,6,d-3-nitrosobenzene, and 2,4,6,-tri-t-butyl-nitrosobenzene have been observed by means of continuous electrolysis in organic media. Strong couplings with nitrogen (aN=37.0 Oe) and one meta proton (aH=3.8 Oe) are observed, leading us to propose that they are σ-radicals; by contrast, the radical—anion of nitrosobenzene is a π radical. The difference is explained on the basis of the electronic structure of the neutral parent compound.