Heteronuclear dipolar dephasing of deuterium quadrupole echoes

Abstract

Analytical expressions are derived for the NMR signal from isolated dipolar coupled 2H–14N spin pairs following a quadrupole echo pulse sequence. The expressions are used to calculate the pulse spacing dependence of the deuterium quadrupole echo intensity and the powder line shape. The theoretical predictions are in good agreement with experimental results obtained for urea-d4 which show that the rigid lattice powder spectra depend significantly on the pulse spacing.