Calculation of 15N NMR chemical shifts of amines in the framework of the density functional theory

The 15 N NMR magnetic shielding constants (followed by recalculation into chemical shifts) in a representative series of amines were calculated in the framework of the density functional theory. The results were compared with experiment. The accuracy factors of this calculation (functional, basis set, solvent effects, and multistandard) were studied. Taking into account all the above factors leads to a noticeable decrease in the average absolute error in the calculation of the 15 N NMR chemical shifts (from 13 to 4 ppm) in a range of their changing in the studies series of compounds of ∼60 ppm (which is 6—7% in relative units).