15N nuclear magnetic resonance spectroscopy. Natural-abundance 15N spectra of aliphatic oximes

¹⁵N chemical shifts of the Z and E isomers of twenty-two ketoximes and fourteen aldoximes have been determined at the natural-abundance level of ¹⁵N, using Fourier transform methods. The influences of π delocalization, methyl substituents and solute concentration on the oxime nitrogen shielding have been determined. The ¹⁵N shifts for oximes of several cycloalkanones have been measured and the influence of ring size on the chemical shifts is discussed.