Abstract: In this work, the NMR characteristics of several nitrogen containing compounds, including Aztreonam, Omeprazole and a Schiff base, were investigated. The results show that quadrupole moment of ¹⁴N nuclei^[1], inter-molecular hydrogen bonding and tautomic equilibria of intra-molecular proton transformation are the major factors influencing the NMR characteristics of these compounds. Based on the results, it is suggested that the aforementioned factors should be considered when designing NMR experiments for and analyzing NMR spectra of nitrogen containing compounds, since knowing the influences of these factors may help gaining more information on the structural and chemical properties of the compounds.

Key words: NMR, nitrogen containing compounds, inter-molecular hydrogen bonding, tautomerism equilibria, quadrupole moment