Complexation of poly-bis-(3-silsesquioxanylpropyl)amino-sulfoxide and-sulfone with rare-earth elements

Polymers of silsesquioxane structure, poly[bis-(3-silsesquioxanyl-propylamino)]sulfoxide ( IV ) and -sulfone ( V ) have been prepared and examined as complexation agents toward samarium(III) and thulium(III). Polymer IV was an effective complexation agent toward both of these elements. However, polymer V was an effective complexation agent only toward thulium(III) ions. The selective complexation of polymer V with thulium is not affected by the presence of excess amounts of lanthanum, cerium, neodymium, or samarium salt. This suggests that polymer V may prove to be useful in rare-earth element (REE) separation and isolation. The selective complexation of V with thulium(III) is also observed in the presence of nickel(II), copper(II), or lead(II) salt.