Heteropolytungstate complexes of the lanthanide elements. Part I. Preparation and reactions

Abstract

Salts of the anions Ln^IIIW₁₀O₃₅ ^7–(Ln = La, Ce, Pr, Nd, Sm, Ho, Er, Yb, and Y) and Ce^IVW₁₀O₃₅ ^6– have been prepared and analysed. The formulae of the previously reported 8-tungstocerates are revised. All the anions are unstable outside the pH range 5·5–8·5, and stable solutions of the free acids cannot be obtained. Lanthanide cations react rapidly with unsaturated heteropolyanions to give complexes LnL and LnL₂(L = SiW₁₁O₃₉ ^8–, etc.). Salts of several of the LnL₂ complexes have been isolated. The mode of co-ordination of L is discussed.