Nickel(II) fluoride

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Nickel(II) fluoride
IUPAC name	Nickel(II) fluoride
Identifiers
CAS number	[10028-18-9]
Properties
Molecular formula	NiF2
Molar mass	96.69 g/mol
Appearance	Yellow solid
Density	4.72 g/cm3, solid
Melting point	1450 °C
Boiling point	1750 °C
Solubility in water	Insoluble
Structure
Crystal structure	Rutile
Coordination geometry	Nickel: Octahedral Oxygen: Trigonal planar
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Nickel(II) fluoride is the chemical compound with the formula NiF₂. Unlike many fluorides, NiF₂ is stable in air. NiF₂ comprises the passivating surface that forms on nickel alloys, e.g. monel, when such materials are used to store or transport HF. It is also used as a catalyst for the synthesis of chlorine pentafluoride.

NiF₂ is prepared by treatment of anhydrous nickel(II) chloride with fluorine at 350 °C:^[1]

NiCl₂ + F₂ → NiF₂ + Cl₂

The corresponding reaction of cobalt(II) chloride results in oxidation of the cobalt, whereas nickel remains in the +2 oxidation state after fluorination because its +3 oxidation state is less stable.

A melt of NiF₂ and KF reacts to give the green compound K₂[NiF₄]. The structure of this material is closely related to some superconducting oxide materials. ^[2]

[edit] References

1. ^ Priest, H. F. “Anhydrous Metal Fluorides” Inorganic Syntheses McGraw-Hill: New York, 1950; Vol. 3, pages 171-183.
2. ^ Balz, D. "Über die Struktur des K₂NiF₄" Naturwissenschaften 1953, page 241.

[edit] External links

• IARC Monograph "Nickel and Nickel compounds"
• National Pollutant Inventory - Flouride and compounds fact sheet
• National Pollutant Inventory - Nickel and compounds fact sheet