Nuclear Magnetic Resonance of Single Crystals of D2O Ice

Quadrupole splitting of the deuteron magnetic resonance was measured in single crystals of solid D2O at —10°C. For deuterons on the hexagonal crystal axis, eQq1/h equaled 213.2±0.8 kc/sec, and | η1 | was equal to 0.100±0.002. For the other deuterons, eQq2/h was found to be equal to 216.4±1.0 kc/sec. No change in the line separations was observed at a temperature of —70°C. No evidence was found for hindered rotation of the D2O molecules nor for intermolecular deuteron transfer at —10°C. Lower limits to the barriers hindering these motions were estimated; these limits permit estimates to be made of hydrogen-bond energies. The coupling constants in the solid are about 30% less than those reported for the free molecule. Most of this decrease must be ascribed to electronic structural changes brought about as a result of hydrogen-bond formation.