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Rhenium hexafluoride

Names
IUPAC name rhenium(VI) fluoride
Other names rhenium hexafluoride
Identifiers
CAS Number	10049-17-9
3D model (JSmol)	Interactive image
ECHA InfoCard	100.030.144
EC Number	233-172-2
PubChem CID	66231
UNII	U1FW6E300T
CompTox Dashboard (EPA)	DTXSID8064931
InChI InChI=1S/6FH.Re/h6*1H;/q;;;;;;+6/p-6
SMILES F(F)(F)(F)(F)F
Properties
Chemical formula	F6Re
Molar mass	300.20 g/mol
Appearance	liquid, or yellow crystalline solid
Density	4.94g/mL
Melting point	18.5 °C (65.3 °F; 291.6 K)
Boiling point	33.7 °C (92.7 °F; 306.8 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references

Rhenium hexafluoride, also rhenium(VI) fluoride, (ReF₆) is a compound of rhenium and fluorine and one of the seventeen known binary hexafluorides.

Chemistry

Rhenium hexafluoride is made by combining rhenium heptafluoride with additional rhenium metal at 300 °C in a pressure vessel.

6 ReF
₇ + Re → 7 ReF
₆

The compound is a Lewis acid and strong oxidant, adducting potassium fluoride and oxidizing nitric oxide to nitrosyl:

2KF + ReF₆ → K₂ReF₈

NO + ReF₆ → [NO][ReF₆]

Description

Rhenium hexafluoride is a liquid at room temperature. At 18.5 °C, it freezes into a yellow solid. The boiling point is 33.7 °C.

The solid structure measured at −140 °C is orthorhombic space group Pnma. Lattice parameters are a = 9.417 Å, b = 8.570 Å, and c = 4.965 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 4.94 g·cm.

The ReF₆ molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (O_h). The Re–F bond length is 1.823 Å.

Use

Rhenium hexafluoride is a commercial material used in the electronics industry for depositing films of rhenium.

References

1. ^ 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. ^ 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.
3. ^ Meshri, D. T. (2000). "Fluorine Compounds, Inorganic, Rhenium". Kirk-Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.1808051413051908.a01. ISBN 0471238961.

Further reading

• Gmelins Handbuch der anorganischen Chemie, System Nr. 70, Rhenium, Part A, pp. 102–105.

External links

• Rhenium hexafluoride at webelements.com.

• Rhenium compounds
• Hexafluorides
• Octahedral compounds