Hydration of the Dy3+ ion in dysprosium chloride solutions determined by neutron diffractiona)

The coordination of water molecules about the Dy3+ ion in a 2.38 m DyCl3 in D2O solution has been determined by neutron scattering. The information was obtained using samples that were identical except for the isotopic species of the Dy3+ ions. The experiment yields the distribution of the deuterium and oxygen atoms in the first hydration shell. Each Dy3+ ion is surrounded by 7.4±0.5 water molecules. The dysprosium–oxygen separation is 2.37 Å and the dysprosium–deuterium separation is 3.04 Å. The cation–water molecule orientation is closer to planar than that which has generally been observed in other aqueous solutions.