Nitrogen nuclear magnetic resonance spectroscopy. Part II. The nitro (nitryl) and nitrate groups

Abstract
14 N Chemical shifts are reported for the nitryl halides, dinitrogen trioxide and tetroxide, dimethyl nitramine, and halogeno-alkyl nitro-compounds. The paramagnetic component –σp of the shifts for nitro-groups attached to halogen, oxygen, nitrogen, or alkyl groups of various polarities, and for NO2 + and NO+, is discussed in terms of the Pople theory. As with the nitroso-compounds (Part I), the electronic excitation energies dominate the variation in –σp, and variation in 〈r–3〉 cannot be neglected.