Iridium Hexafluoride

Iridium hexafluoride
Names
	IUPAC name iridium(VI) fluoride
	Other names iridium hexafluoride
Identifiers
CAS Number	7783-75-7 ;
3D model (JSmol)	Interactive image;
ChemSpider	10323846;
PubChem CID	3014587;
UNII	UP14U33TGX ;
	InChI InChI=1S/6FH.Ir/h61H;/q;;;;;;+6/p-6 Key: JQAZQSHUPWSSPF-UHFFFAOYSA-H; InChI=1/6FH.Ir/h61H;/q;;;;;;+6/p-6/rF6Ir/c1-7(2,3,4,5)6 Key: JQAZQSHUPWSSPF-VYYYRSGCAJ;
	SMILES F[Ir](F)(F)(F)(F)F;
Properties
Chemical formula	IrF6
Molar mass	306.22 g/mol
Appearance	yellow crystalline solid
Density	5.11g/mL
Melting point	44 °C (111 °F; 317 K)
Boiling point	53.6 °C (128.5 °F; 326.8 K)
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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	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 F₂ → IrF₆

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 (O_h). 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]

References

↑ ^1.0 ^1.1 ^1.2 ^1.3 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.
↑ ^2.0 ^2.1 ^2.2 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.
↑ 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 (American Chemical Society (ACS)) 141 (13): 5409–5414. doi:10.1021/jacs.9b00069. ISSN 0002-7863. PMID 30864432.