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.