Potassium hexafluoronickelate(IV)

Potassium hexafluoronickelate(IV)

Names
IUPAC name potassium hexafluoronickelate(IV)
Identifiers
CAS Number	17218-47-2^[scifinder]
ChemSpider	21241633
Jmol interactive 3D	Image
InChI InChI=1S/6FH.2K.Ni/h6*1H;;;/q;;;;;;2*+1;+4/p-6
SMILES [K+].[K+].F[Ni-2](F)(F)(F)(F)F
Properties
Chemical formula	K2NiF6
Molar mass	250.880
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Potassium hexafluoronickelate(IV) is an inorganic compound with the chemical formula K
2NiF
6. It can be produced through the reaction of potassium fluoride, nickel dichloride, and fluorine.

It reacts violently with water, releasing oxygen. It dissolves in anhydrous hydrogen fluoride to produce a light-red solution. Potassium hexafluoronickelate(IV) decomposes at 350 °C, forming potassium hexafluoronickelate(III), nickel(II) fluoride, and fluorine:^[1]

$\rm \ 3 K_2NiF_6 \xrightarrow{\Delta} 2 K_3NiF_6 + NiF_2 + F_2$

Potassium hexafluoronickelate is a very strong oxidant. It can turn chlorine pentafluoride and bromine pentafluoride into ClF+
6 and BrF+
6, respectively:^[2]

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

( X = Cl or Br , -60 °C , aHF = anhydrous hydrogen fluoride )

References

1. (simplified Chinese)张青莲. 《无机化学丛书》第九卷：锰分族、铁系、铂系. 北京: 科学出版社. pp. P333. ISBN 7-03-002238-6.
2. Schroer, Thorsten; Christe, Karl O. (2001). "Novel Synthesis of ClF₆⁺ and BrF₆⁺ Salts". Inorganic Chemistry 40 (10): 2415–9. doi:10.1021/ic001024. PMID 11327921.