Nickel(II) fluoride

Nickel(II) fluoride
IUPAC name Nickel(II) fluoride
Identifiers
CAS number	10028-18-9 Y
PubChem	24825
ChemSpider	23210 Y
RTECS number	QR6825000
Jmol-3D images	Image 1
SMILES F[Ni]F
InChI InChI=1S/2FH.Ni/h2*1H;/q;;+2/p-2 Y Key: DBJLJFTWODWSOF-UHFFFAOYSA-L Y
Properties
Molecular formula	NiF2
Molar mass	96.6902 g/mol
Appearance	Yellowish to green tetragonal crystals
Density	4.72 g/cm3
Melting point	1474°C [1]
Boiling point	1750°C [2]
Solubility in water	4 g/100 ml water (25°C)
Structure
Crystal structure	Rutile
Coordination geometry	Nickel: Octahedral Oxygen: Trigonal planar
Hazards
MSDS	External MSDS
Related compounds
Other anions	Nickel(II) chloride Nickel(II) bromide Nickel(II) iodide
Other cations	Cobalt(II) fluoride Copper(II) fluoride
Y fluoride (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox 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, which is why such materials are good to store or transport hydrogen fluoride or elemental fluorine. Nickel is one of the few materials that can be used to store fluorine because it forms this coating. 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:^[3]

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. Chloride is more easily oxidized than nickel(II). This is a typical halogen displacement reaction, where a halogen plus a less active halide makes the less active halogen and the more active halide. Nickel(II) fluoride is also produced when fluorine reacts with nickel metal.

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.^[4]

Nickel(II) fluoride reacts with strong bases to make nickel(II) hydroxide, a green colored compound.

NiF₂ + 2 NaOH → Ni(OH)₂ + 2 NaF

References

1. ^ http://www.slac.stanford.edu/BFROOT/www/Detector/Backgrounds/BkG4Sim/Planning/Validations/neutronCounters/04_02_85.pdf
2. ^ http://www.indiamart.com/primechemicals/inorganic-fluorine.html
3. ^ Priest, H. F. “Anhydrous Metal Fluorides” Inorganic Syntheses McGraw-Hill: New York, 1950; Vol. 3, pages 171-183.
4. ^ Balz, D. "Über die Struktur des K₂NiF₄" Naturwissenschaften 1953, page 241.

External links

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