Fluoro-complexes of quinquevalent protactinium

Abstract

The preparation, from aqueous hydrofluoric acid solution, of anhydrous heptafluoroprotactinates(V), M₂PaF₇(M = K, NH₄, Rb, and Cs), and of lithium and sodium octafluoroprotactinates(V), M₃PaF₈, is described. Octafluoro-complexes containing larger cations (M = K and Cs) have been prepared by heating together the appropriate alkali-metal fluoride and the heptafluoro-complex in an inert atmosphere. The preparation of hexafluoro-complexes from aqueous hydrofluoric acid is discussed, and some chemical properties, X-ray diffraction data, and infrared spectra are reported for the three classes of compound.