Deuteron and proton magnetic resonance studies of AlCl3.6D2O and AlCl3.6H2O

The angular dependence of the deuteron magnetic resonance line splittings recorded in one plane of rotation of a single crystal of AlCl3 . 6D2O have been used to establish the quadrupole coupling tensor and determine the deuteron positional coordinates. These coordinates are found to be 0.073, 0.187, 0.143; 0.202, 0.204, and 0.087. Proton relaxation times in polycrystalline AlCl3 . 6H2O have been measured as a function of temperature to evaluate the dynamic parameters associated with molecular motion. Twofold motion of H2O with an activation energy of 10.0 + or - 0.5 kcal/mole is found to dominate the relaxation process below 3850K. A second motion with an activation energy of 17.0 + or - 1.0 kcal/mole appears above 3850K and is likely to be translational diffusion of the water molecules