Localization of hydrogen bond deuterons in proton sponges by dipolar solid state ¹⁵N NMR spectroscopy

It is shown that dipolar solid state 15 N NMR spectroscopy can be employed in order to estimate the positions of hydrogen bond deuterons in polycrystalline 15 N labeled proton sponges containing an intramolecular N…H…N hydrogen bond. For singly 15 N labeled 1, 8‐bis(dimethylamino)naphtalene. LPF 6 (1‐h: LH, 1‐d: LD), an asymmetric hydrogen bond with cubic average distances between the two nitrogen atoms and the hydrogen bond deuteron of 1.19 Å and 1.47 Å are obtained. These values are in accordance with the N…H distances of 1.19(7) Å and 1.43(6) Å, obtained previously by x‐ray diffraction at 150 K.