Proton magnetic resonance in aromatic nitro compounds

Abstract

The proton magnetic resonance spectra of several methylnitronaphthalenes, p-nitrotoluene, and nitro-p-xylene have been determined for dilute carbon tetra- chloride solution. The nitro group has little effect upon the chemical shift of the methyl group unless they are "ortho" related. The electronic effects of the nitro group lead to a general low field shift of the ring protons with little distinction between quinonoid and non-quinonoid positions. From the effect of nitro group rotation due to steric hindrance its anisotropic contribution has been estimated in good agreement with other work.