The hydration of Dy3+ and Yb3+ in aqueous solution: A neutron scattering first order difference study

Abstract
The coordination of water molecules around the metal ion in acidified 1 m DyCl3, 1.0 m Dy(ClO4)3, 0.3 m Dy(ClO4)3, and 1.0 m Yb(ClO4)3 solutions in D2O have been determined by the neutron diffraction difference technique. A coordination number of eight is found for the two ions, which depends neither on the counterion, nor on the concentration. The near metal–oxygen and metal–deuterium distances are, respectively, 2.39±0.02 and 3.03±0.02 Å for dysprosium and 2.33±0.02 and 2.98±0.02 Å for ytterbium. A general discussion concerning the hydration of the lanthanide ions is given.