A solvent effect on the conformation of aromatic nitro groups

Abstract

The differences between proton mangetic resonance spectra of aromatic nitro compounds in deuterochloroform and dimethyl sulphoxide solutions are interpreted in terms of increased steric requirements of the nitro group in the latter solvent. In suitably ortho-substituted aromatic nitro compounds this leads to twisting of the nitro group about the Ar- N bond.