Rhodium hexafluoride, also rhodium(VI) fluoride, (RhF<sub>6</sub>) is the inorganic compound of rhodium and fluorine. A black volatile solid, 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.
The RhF<sub>6</sub> molecule has octahedral molecular geometry. Consistent with its d<sup>3</sup> configuration, the six RhâÂÂF bond lengths are equivalent, being 1.824 à. It crystallises in an orthorhombic space group Pnma with lattice parameters of a = 9.323 ÃÂ, b = 8.474 à, and c = 4.910 à.
Rhodium hexafluoride was discovered by American radiochemists in 1961, soon after the discovery of ruthenium hexafluoride. It is prepared by reaction of rhodium metal with an excess of elemental fluorine:
Like some other metal fluorides, RhF<sub>6</sub> is highly oxidizing. It attacks glass, and can even react with elemental oxygen.