Nuclear quadrupole resonance spectra of deuterium are reported for anhydrous 2-imidazolidone (ethylene urea), its hemihydrate, phthalimide, and benzamide at 77 K. Imidazolidone-( N,N′)- d 2 shows a single deuteron site per asymmetric unit, with e 2 qQ/ h = 208.0 kHz and η = 15.4%. The hemihydrate, imidazolidone-(N1,N3)-d 2 · 1 2 D 20 shows two ND sites and one OD site per asymmetric unit: N1- D1 with e 2 qQ/ h = 196.3 kHz, η = 16.8%, N3D3 with e 2 qQ/ h = 204.9 kHz and η = 15.9%, OW-DW with e 2 qQ/ h = 228.2 kHz and 11.4% nonaxiality. These values and multiplicities are consistent with the subsequently determined room-temperature X-ray structures. Dipolar fine structure was observed for the D 20 site, with DD distance = 1.58 6 Å and the field gradient tensor at deuterium is oriented with its principal z axis parallel to the OD bond and its principal y axis perpendicular to the D0D plane. Incomplete dipolar structure was also observed for benzamide-( N)-d 2, the interaction considerably diminished by the crystallographic inequivalence of the two deuterons of the −ND 2 group. The coupling constants and asymmetry parameters for the two crystallographic sites in this compound are 193.0 kHz, 18.1 % (site H6) and 211.1 kHz, 15.9% (site H7). In accord with the known structure of phthalimide-( N)-d 2, a single site is observed with e 2 qQ/ h = 187.6 kHz, η = 16.4%.