Rhodium hexafluoride

Rhodium hexafluoride, also rhodium(VI) fluoride, (RhF₆) is the inorganic compound of rhodium and fluorine. A black volatile solid,^[1] it is a highly reactive material which starts to slowly thermally decompose already at room temperature and a rare example of a rhodium(VI) compound. It is one of seventeen known binary hexafluorides.

Rhodium hexafluoride

Names
IUPAC name rhodium(VI) fluoride
Other names rhodium hexafluoride
Identifiers
CAS Number	13693-07-7
3D model (JSmol)	Interactive image
PubChem CID	20488757
CompTox Dashboard (EPA)	DTXSID80608008
InChI Key: PDNXMXVYNVZBTD-UHFFFAOYSA-H InChI=1/6FH.2Rh/h6*1H;;/q;;;;;;+6/p-6
SMILES F[Rh](F)(F)(F)(F)F
Properties
Chemical formula	F6Rh
Molar mass	216.91 g/mol
Appearance	black crystalline solid[1]
Density	3.71g/mL[2]
Melting point	≈ 70 °C (158 °F; 343 K)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Rhodium hexafluoride was discovered by American radiochemists in 1961, soon after the discovery of ruthenium hexafluoride.^[3] It is prepared by reaction of rhodium metal with an excess of elemental fluorine:^[4]

Rh + 3 F₂ → RhF₆

The RhF₆ molecule has octahedral molecular geometry. Consistent with its d³ configuration, the six Rh–F bond lengths are equivalent, being 1.824 Å.^[2] It crystallises in an orthorhombic space group Pnma with lattice parameters of a = 9.323 Å, b = 8.474 Å, and c = 4.910 Å.

Like some other metal fluorides, RhF₆ is highly oxidizing. It attacks glass,^[4] and can even react with elemental oxygen.^[5]