Osmium hexafluoride explained

Osmium hexafluoride, also osmium(VI) fluoride, (OsF₆) is a compound of osmium and fluorine, and one of the seventeen known binary hexafluorides.

Synthesis

Osmium hexafluoride is made by a direct reaction of osmium metal exposed to an excess of elemental fluorine gas at 300 °C.

+ 3 →

Description

Osmium hexafluoride is a yellow crystalline solid that melts at 33.4 °C and boils at 47.5 °C. The solid structure measured at −140 °C is orthorhombic space group Pnma. Lattice parameters are a = 9.387 Å, b = 8.543 Å, and c = 4.944 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 5.09 g·cm⁻³.

The OsF₆ molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (O_h). The Os–F bond length is 1.827 Å.

Partial hydrolysis of OsF₆ produces OsOF₄.^[1]

References

1. Paine. R. T.. Partial hydrolysis of rhenium and osmium hexafluorides. An improved synthesis and characterization of rhenium oxide tetrafluoride. Inorganic Chemistry. 1 June 1973. 12. 6. 1457–1458. 10.1021/ic50124a060.

^{[2] [3]}

Further reading

• Gmelins Handbuch der anorganischen Chemie, System Nr. 53, Osmium, Supplement Volume 1, pp. 111–114.

External links

• Osmium hexafluoride at webelements.com.