Arsenic pentafluoride

Arsenic pentafluoride
IUPAC name Arsenic pentafluoride
Other names Arsenic(V) fluoride, Arsorane, pentafluoro-
Identifiers
CAS number	7784-36-3 Y
PubChem	82223
ChemSpider	74203 Y
ChEBI	CHEBI:30530 Y
Jmol-3D images	Image 1
SMILES F[As](F)(F)(F)F
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
Properties
Molecular formula	AsF5
Molar mass	169.9136 g mol-1
Appearance	colorless gas
Density	2.138 g cm-3[1]
Melting point	-79.8 ˚C[1]
Boiling point	-52.8 ˚C[1]
Solubility in benzene	soluble
Hazards
EU classification	Toxic (T) Dangerous for the environment (N)
R-phrases	R23/25, R50/53
S-phrases	(S1/2), S20/21, S28, S45, S60, S61
NFPA 704	0 4 1
Related compounds
Related group 5 fluorides	Phosphorus pentafluoride Antimony pentafluoride Bismuth pentafluoride
Related compounds	Arsenic pentachloride Arsenic trifluoride Arsenic pentoxide
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

Arsenic pentafluoride is a chemical compound of arsenic and fluorine. The oxidation state of arsenic is +5.

Synthesis

Arsenic pentafluoride can be prepared by direct combination of arsenic and fluorine^[2]:

2As + 5F₂ → 2AsF₅

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

AsF₃ + F₂ → AsF₅

Properties

Arsenic pentafluoride is a colourless gas and has a trigonal bipyramidal structure.^[2] In the solid state the axial As-F bond lengths are 171.9 pm and the equatorial 166.8 pm.^[2]

Reactions

Arsenic pentafluoride forms halide complexes and is a powerful acceptor as shown by the reaction with sulfur tetrafluoride forming an ionic complex.^[3]

AsF₅ + SF₄ → SF₃⁺ + AsF₆⁻

See also

• List of highly toxic gases

References

1. ^ ^{a b c} Record of Arsenic(V) fluoride in the GESTIS Substance Database from the IFA, accessed on 24/12/2007
2. ^ ^{a b c} Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419. 
3. ^ 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