Nickel(II) fluoride

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Nickel(II) fluoride
Fluorid nikelnatý.PNG
Nickel(II)-fluoride-unit-cell-3D-balls.png
Identifiers
CAS number 10028-18-9 YesY
PubChem 24825
ChemSpider 23210 YesY
EC number 233-071-3
RTECS number QR6825000
Jmol-3D images Image 1
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
Solubility insoluble in alcohol, ether
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
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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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[edit]

  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[edit]