Iridium hexafluoride

Iridium hexafluoride
Iridium(VI) fluoride
Iridium(VI) fluoride
Names
IUPAC name
iridium(VI) fluoride
Other names
iridium hexafluoride
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.113
UNII
  • InChI=1S/6FH.Ir/h6*1H;/q;;;;;;+6/p-6
    Key: JQAZQSHUPWSSPF-UHFFFAOYSA-H
  • InChI=1/6FH.Ir/h6*1H;/q;;;;;;+6/p-6/rF6Ir/c1-7(2,3,4,5)6
    Key: JQAZQSHUPWSSPF-VYYYRSGCAJ
  • F[Ir](F)(F)(F)(F)F
Properties
IrF6
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
Hazards
GHS labelling:[3]
GHS05: Corrosive
Danger
H290, H314
P234, P260, P264, P280, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P321, P363, P390, P405, P501
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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Infobox references

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.

Synthesis

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
2
IrF
6

Description

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.[4]

It is able to oxidize elemental chlorine to the blue-colored salt Cl
4
IrF
6
(containing Cl4+, originally misidentified as Cl2+), in a process somewhat analogous to the oxidation of elemental oxygen by PtF6 (which yields the O2+ containing O
2
PtF
6
).[5][6]

References

  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 Drews, T.; Supeł, J.; Hagenbach, A.; Seppelt, K. (May 2006). "Solid State Molecular Structures of Transition Metal Hexafluorides". Inorganic Chemistry. 45 (9): 3782–8. doi:10.1021/ic052029f. PMID 16634614.
  3. ^ PubChem. "Iridium hexafluoride". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-04-06.
  4. ^ 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.
  5. ^ Seidel, Stefan; Seppelt, Konrad (2000-11-03). "The Cl4+ Ion". Angewandte Chemie. 39 (21): 3923–3925. doi:10.1002/1521-3773(20001103)39:21<3923::AID-ANIE3923>3.0.CO;2-Y.
  6. ^ Graham, Lionell (1978-10-01). The Oxidizing Power of Some Platinum Metal Fluorides (PDF) (PhD thesis). Lawrence Berkeley National Laboratory. p. 55. Archived from the original (PDF) on 2024-09-16. Retrieved 2026-01-21.

Further reading