Molybdenum hexafluoride

Molybdenum hexafluoride
Identifiers
CAS number	7783-77-9 Y
Properties
Molecular formula	MoF6
Molar mass	209.93 g/mol
Appearance	white crystals or colorless liquid hygroscopic
Density	2.54 g/cm3
Melting point	17.5 °C, 291 K, 64 °F
Boiling point	34 °C, 307 K, 93 °F
Solubility in water	hydrolyzes
Structure
Crystal structure	Orthorhombic, oP28
Space group	Pnma, No. 62
Coordination geometry	octahedral (Oh)
Dipole moment	0
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Molybdenum hexafluoride is the highest fluoride of molybdenum. It is a solid which melts just below room temperature; in water, it hydrolyses to give hydrofluoric acid.^[1]

It has few uses, and generally appears as an impurity in uranium hexafluoride (in the nuclear industry) or tungsten hexafluoride (in the semiconductor industry; WF₆ is used for chemical vapour deposition of tungsten); it can be removed from the latter by reduction of a WF₆-MoF₆ mixture with any of a number of elements including molybdenum at moderately elevated temperature.^[2][3]

References

1. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419. 
2. ^ US-Patent 5234679: Method of Refining Tungsten Hexafluoride Containing Molybdenum Hexafluoride as an Impurity, 10. August 1993.
3. ^ US-Patent 6896866: Method for Purification of Tungsten Hexafluoride, 24. Mai 2005.