Proton magnetic resonance studies of N-substituted styrenimines: IX. NMR studies of aliphatic nitrogen-containing compounds☆

Abstract Proton magnetic resonance spectra of styrenimine and its derivatives have been investigated. The assignment of signals of aziridine ring protons has been carried out by the proton magnetic double resonance technique at 100 MHz to make full analyses of the spectra. Coupling constants of geminal protons in the ring are correlated with the electronegativity of N-substitutents; the correlation shows a positive trend. Long-range spin couplings between the N-methyl and ring protons were found to be stronger when they are cis than when trans : the sign of the coupling constant in the former case is conjectured to be negative. The stereospecific 14 NCH coupling is also discussed in connection with the orientation of the lone-pair on nitrogen.