The Preparation and Characterization of Three New Fluorotungstate Anions Having the Dawson Structure [Cu⁺W₁₇O₅₄F₈NaH₄]^8-, [MgW¹⁷O⁵⁷F₅NaH₆]^8-, and [Fe⁺³W⁺⁵W₁₆⁺⁶O₅₅F₇NaH₄]^8-

Abstract

The ammonium salts of the above anions have been isolated in the crystalline form as (NH₄)₈[Cu⁺W₁₇O₅₄F₈NaH₄]˙13H₂O, (NH₄)₈[MgW₁₇O₅₇F₅NaH₆]˙10H₂O, and(NH₄)₈[Fe⁺³W⁺⁵W₁₆ ⁺⁶O₅₅F₇NaH₄]˙12H₂O. Evidence from chemical analysis, Fast Atom Bombardment Mass Spectrometry, spectroscopy (vis, IR), and X-ray powder patterns, indicated that the three anions have the Dawson-Wells structure. The metal ion is Cu⁺ in the first, Mg⁺² in the second and Fe⁺³ in the third which replaces one W⁺⁶ of the eighteen tungsten atoms in the original Dawson structure.