Arsenic pentafluoride is a
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
of
arsenic
Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...
and
fluorine
Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...
. It is a toxic, colorless gas. The
oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical Electrical charge, charge of an atom if all of its Chemical bond, bonds to other atoms are fully Ionic bond, ionic. It describes the degree of oxidation (loss of electrons ...
of arsenic is +5.
Synthesis
Arsenic pentafluoride can be prepared by direct combination of arsenic and
fluorine
Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...
:
:2As + 5F
2 → 2AsF
5
It can also be prepared by the reaction of
arsenic trifluoride and fluorine:
:AsF
3 + F
2 → AsF
5
or the addition of fluorine to
arsenic pentoxide or
arsenic trioxide.
:2As
2O
5 + 10F
2 → 4AsF
5 + 5O
2
:2As
2O
3 + 10F
2 → 4AsF
5 + 3O
2
Properties
Arsenic pentafluoride is a colourless gas and has a
trigonal bipyramidal structure.
In the solid state the axial As−F bond lengths are 171.9 pm and the equatorial 166.8 pm.
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.
[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), ]
:AsF
5 + SF
4 → SF
3+ + AsF
6−
See also
*
List of highly toxic gases
References
{{fluorine compounds
Arsenic(V) compounds
Fluorides
Arsenic halides