my-server
← Wiki

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.

Synthesis

Arsenic pentafluoride can be prepared by direct combination of arsenic and fluorine:

2As + 5F<sub>2</sub> → 2AsF<sub>5</sub>

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

AsF<sub>3</sub> + F<sub>2</sub> → AsF<sub>5</sub>

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

2As<sub>2</sub>O<sub>5</sub> + 10F<sub>2</sub> → 4AsF<sub>5</sub> + 5O<sub>2</sub>
2As<sub>2</sub>O<sub>3</sub> + 10F<sub>2</sub> → 4AsF<sub>5</sub> + 3O<sub>2</sub>

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.

AsF<sub>5</sub> + SF<sub>4</sub> → SF<sub>3</sub><sup>+</sup> + AsF<sub>6</sub><sup>−</sup>

See also

References