Selenium hexafluoride

Selenium hexafluoride
Names
	IUPAC name Selenium hexafluoride
	Other names Selenium(VI) fluoride, Selenium fluoride
Identifiers
CAS Number	7783-79-1 ;
3D model (JSmol)	Interactive image;
ChemSpider	22964 ;
ECHA InfoCard	100.149.506
PubChem CID	24558;
RTECS number	VS9450000;
UNII	H91D37I668 ;
CompTox Dashboard (EPA)	DTXSID00999041 ;
	InChI InChI=1S/F6Se/c1-7(2,3,4,5)6 Key: LMDVZDMBPZVAIV-UHFFFAOYSA-N ; InChI=1S/F6Se/c1-7(2,3,4,5)6 Key: LMDVZDMBPZVAIV-UHFFFAOYAP;
	SMILES F[Se](F)(F)(F)(F)F;
Properties
Chemical formula	SeF6
Molar mass	192.9534 g/mol
Appearance	colourless gas
Density	0.007887 g/cm3
Melting point	−39 °C (−38 °F; 234 K)
Boiling point	−34.5 °C (−30.1 °F; 238.7 K) sublimes
Solubility in water	insoluble
Vapor pressure	>1 atm (20°C)
Magnetic susceptibility (χ)	−51.0·10−6 cm3/mol
Refractive index (nD)	1.895
Structure
Crystal structure	Orthorhombic, oP28
Space group	Pnma, No. 62
Coordination geometry	octahedral (Oh)
Dipole moment	0
Thermochemistry
Std enthalpy of; formation (ΔfH⦵298)	-1030 kJ/mol
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	toxic, corrosive
NFPA 704 (fire diamond)	3 0 0
	Lethal dose or concentration (LD, LC):
LCLo (lowest published)	10 ppm (rat, 1 hr); 10 ppm (mouse, 1 hr); 10 ppm (guinea pig, 1 hr)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 0.05 ppm (0.4 mg/m3)
REL (Recommended)	TWA 0.05 ppm
IDLH (Immediate danger)	2 ppm
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Selenium hexafluoride is the inorganic compound with the formula SeF₆. It is a very toxic colourless gas described as having a "repulsive" odor.^[5] It is not widely encountered and has no commercial applications.^[6]

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SeF₆ has octahedral molecular geometry with an Se−F bond length of 168.8 pm. In terms of bonding, it is hypervalent.

SeF₆ can be prepared from the elements.^[7] It also forms by the reaction of bromine trifluoride (BrF₃) with selenium dioxide. The crude product can be purified by sublimation.

The relative reactivity of the hexafluorides of S, Se, and Te follows the order TeF₆ > SeF₆ > SF₆, the latter being completely inert toward hydrolysis until high temperatures. SeF₆ also resists hydrolysis.^[3] The gas can be passed through 10% NaOH or KOH without change, but reacts with gaseous ammonia at 200 °C.^[8]

Although selenium hexafluoride is quite inert and slow to hydrolyze, it is toxic even at low concentrations,^[9] especially by longer exposure. In the U.S., OSHA and ACGIH standards for selenium hexafluoride exposure is an upper limit of 0.05 ppm in air averaged over an eight-hour work shift. Additionally, selenium hexafluoride is designated as IDLH chemical with a maximum allowed exposure limit of 2 ppm.^[10]

[1]
Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
[2]
NIOSH Pocket Guide to Chemical Hazards. "#0551". National Institute for Occupational Safety and Health (NIOSH).
[3]
Wiberg, E.; Holleman, A. F. (2001). Inorganic Chemistry. Elsevier. ISBN 0-12-352651-5.
[4]
"Selenium hexafluoride". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
[5]
"Material Safety" (PDF). Retrieved 2010-07-24.
[6]
Langner, B. E. "Selenium and Selenium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a23_525. ISBN 978-3527306732.
[7]
Yost, D. M.; Simons, J. H. (1939). "Sulfur, Selenium, and Tellurium Hexafluorides". Inorganic Syntheses. Vol. 1. pp. 121–122. doi:10.1002/9780470132326.ch44. ISBN 9780470132326.
[8]
Krebs, B.; Bonmann, S.; Eidenschink, I. (1994). "Selenium-Inorganic Chemistry". In King, R. B. (ed.). Encyclopedia of Inorganic Chemistry. John Wiley & Sons. ISBN 0-471-93620-0.
[9]
"Medical Management Guidelines for Selenium Hexafluoride (SeF₆)". CDC ATSDR. Archived from the original on May 28, 2010. Retrieved 2010-07-24.
[10]
Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)

[CRC-1] [1]
Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.

[PGCH-2] [2]
NIOSH Pocket Guide to Chemical Hazards. "#0551". National Institute for Occupational Safety and Health (NIOSH).

[Wiberg&Holleman-3] [3]
Wiberg, E.; Holleman, A. F. (2001). Inorganic Chemistry. Elsevier. ISBN 0-12-352651-5.

[4] [4]
"Selenium hexafluoride". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).

[decompose-5] [5]
"Material Safety" (PDF). Retrieved 2010-07-24.

[6] [6]
Langner, B. E. "Selenium and Selenium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a23_525. ISBN 978-3527306732.

[7] [7]
Yost, D. M.; Simons, J. H. (1939). "Sulfur, Selenium, and Tellurium Hexafluorides". Inorganic Syntheses. Vol. 1. pp. 121–122. doi:10.1002/9780470132326.ch44. ISBN 9780470132326.

[Krebs-8] [8]
Krebs, B.; Bonmann, S.; Eidenschink, I. (1994). "Selenium-Inorganic Chemistry". In King, R. B. (ed.). Encyclopedia of Inorganic Chemistry. John Wiley & Sons. ISBN 0-471-93620-0.

[toxic-9] [9]
"Medical Management Guidelines for Selenium Hexafluoride (SeF₆)". CDC ATSDR. Archived from the original on May 28, 2010. Retrieved 2010-07-24.

[10] [10]
Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)

[5]

[6]

[1]

[2]

[3]

[4]

[7]

[8]

[9]

[10]

Selenium hexafluoride

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Selenium hexafluoride

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Structure, preparation, and reactions

Safety

References

External links