Deuteron Magnetic Resonance Study of Some Crystals Containing an O—D···O Bond

A deuteron magnetic resonance study was made on four compounds with an O—D···O hydrogen bond of different strengths. The deuteron quadrupole coupling constant eqQ, asymmetry parameter η, and the directions of the field gradient tensor were determined. The eqQ and η obtained are: KDCO3154.4±0.6 kc/sec,0.194±0.018,(COOD)22D2O D1(water)230.3±2.0 kc/sec,0.062±0.006,D2(water)219.1±2.0 kc/sec,0.16±0.03,} (at−70∘C) D1 and D2121±3 kc/sec,0.93±0.02,(at 67∘C) D3(carboxyl)139.2±0.8 kc/sec,0.098±0.005,ND4D2PO4 (acid D)119.6±0.8 kc/sec,0.053±0.008,K, D−maleate 56.0±0.8 kc/sec,0.53±0.07.The results are discussed in relation to the crystal structure in each case. It was found that the oxalic acid dihydrate crystal used was a new modification, different from the ordinary one. Reorientational motion of a water molecule similar to that in other hydrated crystals was observed in oxalic acid dihydrate from the measurement at different temperatures. A barrier to this motion of 10.0 kcal/mole was determined from the te...