Studies on hydrolytic polymerization of rare-earth metal ions-V Hydrolytic polymerization of Dy(3+)

The hydrolytic polymerization of Dy(3+) was determined by the equilibrium-pH method. The concentration of Dy(3+) was varied from 0.1 to 0.6M. The composition and hydrolysis constants of the Dy(3+) hydrolysis products were obtained by a graphical method and then refined by computer fitting and pq analysis. The results show that the species in the Dy(3+) solution are Dy(OH)](2+), [Dy(2)(OH)(2)](4+) and [Dy(3)(OH)(3)](6+), but the last of these is a minor species. The behaviour of Dy(3+) is the same as that of Er(3+) and Yb(3+) but different from that of the medium lanthanide ions Sm(3+), Eu(3+) and Gd(3+).