Arsenic pentafluoride

Arsenic pentafluoride is a chemical compound of arsenic and fluorine. It is a toxic, colorless gas. The oxidation state of arsenic is +5.

Arsenic pentafluoride

Structural formula Ball-and-stick model
Names
IUPAC name Arsenic pentafluoride
Other names Arsenic(V) fluoride, Arsorane, pentafluoro-
Identifiers
CAS Number	7784-36-3 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:30530 Y
ChemSpider	74203 Y
ECHA InfoCard	100.029.146
PubChem CID	82223
UNII	I54752Q0OJ Y
CompTox Dashboard (EPA)	DTXSID4064842
InChI InChI=1S/AsF5/c2-1(3,4,5)6 Y Key: YBGKQGSCGDNZIB-UHFFFAOYSA-N Y InChI=1/AsF5/c2-1(3,4,5)6 Key: YBGKQGSCGDNZIB-UHFFFAOYAA
SMILES F[As](F)(F)(F)F
Properties
Chemical formula	AsF5
Molar mass	169.9136 g mol−1
Appearance	colorless gas
Density	2.138 kg/m3 (g/L)[1]
Melting point	−79.8 ˚C[1]
Boiling point	−52.8 ˚C[1]
Solubility	Ethanol, Dimethylether, Benzene
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H319, H350, H361, H370, H372
Precautionary statements	P201, P202, P260, P264, P270, P280, P281, P305+P351+P338, P307+P311, P308+P313, P314, P321, P337+P313, P405, P410+P403, P501
NFPA 704 (fire diamond)	4 0 1 W OX
NIOSH (US health exposure limits):
PEL (Permissible)	[1910.1018] TWA 0.010 mg/m3[2]
REL (Recommended)	Ca C 0.002 mg/m3 [15-minute][2]
IDLH (Immediate danger)	Ca [5 mg/m3 (as As)][2]
Related compounds
Related group 5 fluorides	Phosphorus pentafluoride Antimony pentafluoride Bismuth pentafluoride
Related compounds	Arsenic pentachloride Arsenic trifluoride Arsenic pentoxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Synthesis

Arsenic pentafluoride can be prepared by direct combination of arsenic and fluorine:^[3]

2As + 5F₂ → 2AsF₅

It can also be prepared by the reaction of arsenic trifluoride and fluorine:

AsF₃ + F₂ → AsF₅

or the addition of fluorine to arsenic pentoxide or arsenic trioxide.

2As₂O₅ + 10F₂ → 4AsF₅ + 5O₂

2As₂O₃ + 10F₂ → 4AsF₅ + 3O₂

Properties

Arsenic pentafluoride is a colourless gas and has a trigonal bipyramidal structure.^[3] In the solid state the axial As−F bond lengths are 171.9 pm and the equatorial 166.8 pm. ^[3] Its point group is D3h.

Reactions

Arsenic pentafluoride forms halide complexes and is a powerful fluoride acceptor. An example is the reaction with sulfur tetrafluoride, forming an ionic hexafluoroarsenate complex.^[4]

AsF₅ + SF₄ → SF₃⁺ + AsF₆⁻

See also

• List of highly toxic gases

References

1. Record of Arsenic(V) fluoride in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 24/12/2007.
2. NIOSH Pocket Guide to Chemical Hazards. "#0038". National Institute for Occupational Safety and Health (NIOSH).
3. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
4. An investigation of the structures of the adducts of SF₄ with BF₃, PF₅, AsF₅, and SbF₅ in the solid state and in solution in HF, M. Azeem, M. Brownstein, and R. J. Gillespie Can. J. Chem. 47(22): 4159–4167 (1969), doi:10.1139/v69-689