Osmium hexafluoride

Osmium hexafluoride

Unit cell of osmium hexafluoride.
Names
IUPAC name osmium(VI) fluoride
Other names osmium hexafluoride
Identifiers
CAS Number	13768-38-2 Y
3D model ( JSmol )	Interactive image
ChemSpider	109930
ECHA InfoCard	100.033.969
PubChem CID	123327
UNII	1G36E253R5 Y
CompTox Dashboard (EPA)	DTXSID50160269
InChI InChI=1S/6FH.Os/h6*1H;/q;;;;;;+6/p-6 Key: MLKFZZUUYQWFMO-UHFFFAOYSA-H InChI=1/6FH.Os/h6*1H;/q;;;;;;+6/p-6/rF6Os/c1-7(2,3,4,5)6 Key: MLKFZZUUYQWFMO-ZXTFGAQLAX
SMILES F[Os](F)(F)(F)(F)F
Properties
Chemical formula	OsF6
Molar mass	304.22 g/mol
Appearance	yellow crystalline solid[1]
Density	5.09g/mL[2]
Melting point	33.4 °C (92.1 °F; 306.5 K)[1]
Boiling point	47.5 °C (117.5 °F; 320.6 K)[1]
Structure
Space group	Pnma, No. 62
Lattice constant	a = 938.7 pm, b = 854.3 pm, c = 494.4 pm[3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

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.

Os + 3 F
₂ → OsF
₆

Description

Osmium hexafluoride is a yellow crystalline solid that melts at 33.4 °C and boils at 47.5 °C.^[1] 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.^[2]

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.^[2]

Partial hydrolysis of OsF₆ produces OsOF₄.^[4]

References