Tin(IV) fluoride is a chemical compound of tin and fluorine with the chemical formula SnF4 and is a white solid with a melting point above 700 °C.[1]

Tin(IV) fluoride
Unit cell of tin(IV) fluoride
Unit cell of tin(IV) fluoride
Names
IUPAC name
tin(IV) fluoride
Other names
stannic fluoride, tin tetrafluoride
Identifiers
3D model (JSmol)
ECHA InfoCard 100.029.105 Edit this at Wikidata
EC Number
  • 232-016-0
UNII
  • InChI=1S/4FH.Sn/h4*1H;/q;;;;+4/p-4
  • [F-].[F-].[F-].[F-].[Sn+4]
Properties
SnF4
Molar mass 194.704 g/mol
Appearance white solid
Melting point above 700 °C (sublimes)
Structure
Tetragonal, tI10
I4/mmm, No. 139
Related compounds
Other anions
Tin(IV) chloride
Tin(IV) bromide
Tin(IV) iodide
Other cations
Carbon tetrafluoride
Silicon tetrafluoride
Germanium tetrafluoride
Tin tetrafluoride
Lead tetrafluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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SnF4 can be prepared by the reaction of tin metal with fluorine gas:[2]

Sn + 2F2 → SnF4

However, a passivating metal fluoride layer will be created and the surface will eventually become unreactive. An alternative synthesis is the reaction of SnCl4 with anhydrous hydrogen fluoride:[1]

SnCl4 + 4HF → SnF4 + 4HCl

With alkali metal fluorides (e.g. KF) hexafluorostannates are produced (e.g.K2SnF6), which contain the octahedral SnF62− anion. SnF4 behaves as a Lewis acid and adducts L2·SnF4 and L·SnF4 have been produced.[2]

Structure

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Unlike the other tin tetrahalides, tin(IV) chloride, tin(IV) bromide, and tin(IV) iodide, which contain tetrahedrally coordinated tin, tin(IV) fluoride contains planar layers of octahedrally coordinated tin, where the octahedra share four corners and there are two terminal, unshared, fluorine atoms trans to one another.[3] The melting point of SnF4 is much higher (700 °C) than the other tin(IV) halides which are relatively low melting, (SnCl4, −33.3 °C; SnBr4, 31 °C; SnI4, 144 °C).[1] The structure can also be contrasted with the tetrafluorides of the lighter members of group 14, (CF4, SiF4 and GeF4) which in the solid state form molecular crystals.[2]

See also

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References

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  1. ^ a b c Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements (2nd ed.). Oxford:Butterworth-Heinemann. pp. 381. ISBN 0-7506-3365-4.
  2. ^ a b c Holleman, A. F.; Wiberg, E.; Wiberg, N. (2001). Inorganic Chemistry, 1st Edition. Academic Press. p. 908. ISBN 0-12-352651-5.
  3. ^ Inorganic Chemistry [Paperback],2d Edition, Housecroft, Sharpe,2004, Pearson Education ISBN 0130399132, ISBN 978-0130399137