DOI: 10.1002/mrc.1460

A GIAO/DFT study of 1H, 13C and 15N shieldings in amines and its relevance in conformational analysis

The ¹H, ¹³C and ¹⁵N absolute shieldings of 13 amines were calculated at the GIAO/B3LYP/6–311++G** level. For some compounds (ethylamine, piperidine and 1-methylpiperidine) two conformations were calculated. The ¹³C and ¹⁵N data could be correctly correlated with experimental chemical shifts, allowing the conformation of 1-methylpiperidine to be established. The ¹H NMR absolute shieldings, although less well correlated with δ values, were used to account for the anisotropy effects of the N lone pair.