Potassium hexafluoronickelate(IV) is an inorganic compound with the chemical formula . It can be produced through the reaction of

potassium fluoride Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide and occurs naturally as the rare ...

, nickel dichloride, and

fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactiv ...

. It reacts violently with water, releasing oxygen. It dissolves in anhydrous

hydrogen fluoride Hydrogen fluoride (fluorane) is an inorganic compound with the chemical formula . This colorless gas or liquid is the principal industrial source of fluorine, often as an aqueous solution called hydrofluoric acid. It is an important feedstock ...

to produce a light-red solution. Potassium hexafluoronickelate(IV) decomposes at 350 °C, forming potassium hexafluoronickelate(III), nickel(II) fluoride, and

: :

\rm \ 3 K_2NiF_6 \xrightarrow 2 K_3NiF_6 + NiF_2 + F_2

Potassium hexafluoronickelate is a strong oxidant. It can turn

chlorine pentafluoride Chlorine pentafluoride is an interhalogen compound with formula ClF5. This colourless gas is a strong oxidant that was once a candidate oxidizer for rockets. The molecule adopts a square pyramidal structure with C4v symmetry, as confirmed by ...

and

bromine pentafluoride Bromine pentafluoride, Br F5, is an interhalogen compound and a fluoride of bromine. It is a strong fluorinating agent. BrF5 finds use in oxygen isotope analysis. Laser ablation of solid silicates in the presence of BrF5 releases O2 for subseq ...

into and , respectively: :

\rm \ K_2NiF_6 + 5 AsF_5 + XF_5 \xrightarrow XF_6AsF_6 + Ni(AsF_6)_2 + 2KAsF_6

:( X = Cl or Br , -60 °C , aHF = anhydrous hydrogen fluoride). Potassium hexafluoronickelate decomposes at high temperatures to release fluorine gas; like terbium(IV) fluoride, the emitted fluorine is primarily monatomic rather than the typical diatomic. It adopts the structure seen for K₂PtCl₆ and Mg₂FeH₆.Taylor, J. C. "A comparison of profile decomposition and Rietveld methods for structurtal refinement with powder diffraction data" Zeitschrift für Kristallographie 1987, volume 181, p151-160.

References

Potassium compounds Nickel complexes Fluoro complexes {{Inorganic-compound-stub