NMR Studies of Single Crystal ND4Cl

The 2D and 14N NMR spectra in single crystals of ND4Cl have been studied from room temperature to −175°C. At high temperatures, motion of the ammonium ion narrows the NMR resonances and averages out both dipole—dipole and quadrupole interactions. As the temperature is lowered, a linewidth transition occurs and quadrupole splittings of the 2D spectrum appear. No splitting is found for the 14N spectrum in both NH4Cl and ND4Cl. From crystal rotation studies, the 2D quadrupole coupling is determined to be 180.1±1.0 kHz and the asymmetry parameter to be 0.00±0.01.