Unstable intermediates. Part XXXVIII. Electron resonace spectra of aromatic nitro-anions: sigma–pi parameters for nitro–oxygen bonds

Abstract

New values for the σ–π parameters for nitrogen–oxygen bonds are deduced from the 14N hyperfine coupling constants of various small radicals. The results are used to support an earlier postulate that there may be a significant deviation from planarity at the nitrogen atom in aromatic nitro-anions, the deviation increasing as the spindensity of the nitro-group increases.