Perfluoroammonium and cesium fluorotungstates

Article abstract of DOI:10.1021/ic50226a021

The syntheses of NF₄⁺ salts containing fluorotungstate anions were studied. The new NF₄WOF₅ salt was prepared by the reaction of WOF₄ with a concentrated solution of NF₄HF₂ in anhydrous HF. It is a white solid, stable up to 60°C. At higher temperatures it decomposes to NF₄W₂O₂F₉, NF₃, OF₂, and WF₆. The ionic nature of NF₄WOF₅ in the solid state was established by vibrational spectroscopy, but in dilute HF solutions the WOF₅^- anion solvolyzes according to 2WOF₅^- + HF ? W₂O₂F₉^- + HF₂^-. In HF solution WF₆^- is readily oxidized by NF₄⁺ to yield WF₆ and NF₃. The syntheses and some reaction chemistry and properties of CsWOF₅, CsW₂O₂F₉, Cs₂WO₂F₄, and CsWF₆ are discussed.