Potassium tetrafluoronickelate

Potassium tetrafluoronickelate is the inorganic compound with the formula K2NiF4. It features octahedral (high spin) Ni centers with Ni-F bond lengths of 2.006 Å. This green solid is a salt of tetrafluoronickelate. It is prepared by melting a mixture of nickel(II) fluoride, potassium fluoride, and potassium bifluoride.[1] The compound adopts a perovskite-like structure consisting of layers of octahedral Ni centers interconnected by doubly bridging fluoride ligands. The layers are interconnected by potassium cations. It is one of the principal Ruddlesden-Popper phases. Early discoveries on cuprate superconductors focused on compounds with structures closely related to K2NiF4, e.g. lanthanum cuprate and derivative lanthanum barium copper oxide.

Potassium tetrafluoronickelate
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 237-595-3
  • InChI=1S/4FH.2K.Ni/h4*1H;;;/q;;;;2*+1;+2/p-4
    Key: UIRGKRRTSXFSTG-UHFFFAOYSA-J
  • F[Ni-2](F)(F)F.[K+].[K+]
Properties
F4K2Ni
Molar mass 212.8836 g·mol−1
Appearance green solid
Density 3.36 g/cm3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Nickel difluoride layers that comprise K2NiF4.

References

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  1. ^ Yeh, S. K.; Wu, S. Y.; Lee, C. S.; Wang, Y. (1993). "Electron-Density Distribution in a Crystal of Potassium Tetrafluoronickelate, K2NiF4". Acta Crystallographica Section B: Structural Science. 49 (5): 806–811. doi:10.1107/S0108768193003246.