Iridium hexafluoride
Iridium(VI) fluoride
IUPAC name
iridium(VI) fluoride
Other names
iridium hexafluoride
3D model (JSmol)
ECHA InfoCard 100.029.113 Edit this at Wikidata
  • InChI=1S/6FH.Ir/h6*1H;/q;;;;;;+6/p-6
  • InChI=1/6FH.Ir/h6*1H;/q;;;;;;+6/p-6/rF6Ir/c1-7(2,3,4,5)6
  • F[Ir](F)(F)(F)(F)F
Molar mass 306.22 g/mol
Appearance yellow crystalline solid[1]
Density 5.11g/mL[2]
Melting point 44 °C (111 °F; 317 K)[1]
Boiling point 53.6 °C (128.5 °F; 326.8 K)[1]
Solubility soluble in HF
Related compounds
Other cations
rhodium hexafluoride
osmium hexafluoride
platinum hexafluoride
Related compounds
iridium(V) fluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Iridium hexafluoride, also iridium(VI) fluoride, (IrF6) is a compound of iridium and fluorine and one of the seventeen known binary hexafluorides. It is one of only a few compounds with iridium in the oxidation state +6.


Iridium hexafluoride is made by a direct reaction of iridium metal in an excess of elemental fluorine gas at 300 °C. However, it is thermally unstable and must be frozen out of the gaseous reaction mixture to avoid dissociation.

Ir + 3 F


Iridium hexafluoride is a yellow crystalline solid that melts at 44 °C and boils at 53.6 °C.[1] The solid structure measured at −140 °C is orthorhombic space group Pnma. Lattice parameters are a = 9.411 Å, b = 8.547 Å, and c = 4.952 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 5.11 g·cm−3.[2]

The IrF6 molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (Oh). The Ir–F bond length is 1.833 Å.[2]

Calculations suggest that fluorine might react with iridium hexafluoride at 39 GPa to form IrF8.[3]


  1. ^ a b c d CRC Handbook of Chemistry and Physics, 90th Edition, CRC Press, Boca Raton, Florida, 2009, ISBN 978-1-4200-9084-0, Section 4, Physical Constants of Inorganic Compounds, p. 4-85.
  2. ^ a b c T. Drews, J. Supeł, A. Hagenbach, K. Seppelt: "Solid State Molecular Structures of Transition Metal Hexafluorides", in: Inorganic Chemistry, 2006, 45 (9), S. 3782–3788; doi:10.1021/ic052029f; PMID 16634614.
  3. ^ Lin, Jianyan; Zhao, Ziyuan; Liu, Chunyu; Zhang, Jing; Du, Xin; Yang, Guochun; Ma, Yanming (2019-03-13). "IrF8 Molecular Crystal under High Pressure". Journal of the American Chemical Society. 141 (13). American Chemical Society (ACS): 5409–5414. doi:10.1021/jacs.9b00069. ISSN 0002-7863. PMID 30864432. S2CID 76664353.

Further reading