The proton resonance spectrum of<i>m</i>-dinitrobenzene, the AB₂X system

Abstract

The proton resonance spectrum of meta-dinitrobenzene is reported and analysed at 60 Mc/s as an AB2 X spectrum and at 29·9200 Mc/s as an AB2 C spectrum. The matrix elements for both systems are given and from these the explicit functions for the transition energy levels and intensities for the AB2 X system are derived. It is practicable to determine the relative signs of only the two larger coupling constants in this case, and it was found from the spectrum at lower field that these have the same sign.