Solvent versus substituent effects on the nitrogen NMR shielding of the nitro‐group in substituted benzenes

Abstract

AbstractIntermolecular effects are shown to induce a variation of about 5 ppm in the nitrogen NMR shieldings of aromatic nitro groups. The latter turn out to be comparable to those exerted by substituents in nitrobenzene derivatives in solutions in a given solvent. Substituent effects on the NO2 nitrogen shielding in nitro benzenes, in a given solvent, seem to reflect contributions from the so‐called field‐inductive effects on the electron charge distribution in such systems, and are insensitive to the resonance effects concerned with the delocalized pπ‐electron systems involved.