Gold(V) fluoride
From Wikipedia, the free encyclopedia
| Gold(V) fluoride | |
|---|---|
 |
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| IUPAC name | Gold(V) fluoride |
| Other names | gold pentafluoride |
| Identifiers | |
| CAS number | [57542-85-5] |
| Properties | |
| Molecular formula | AuF5 |
| Molar mass | 291.959 g/mol |
| Appearance | red unstable solid |
| Melting point |
60 °C (Decomposes) |
| Solubility in water | Decomposes |
| Hazards | |
| Main hazards | Corrosive, toxic |
| Related compounds | |
| Other cations | SbF5, BrF5, IF5 |
| Related compounds | AuF3 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Gold(V) fluoride is a fluoride of gold where gold is in its highest known oxidation state. It is a red solid and is very corrosive. It is very reactive and unstable at room temperature, and liberates fluorine spontaneously. In water, it hydrolyses to fluorine and a mixture of gold hydroxides and oxides.
The structure of gold(V) fluoride in the solid state is dimeric, better represented by the formula Au2F10, with hexacoordinated gold and an octahedral arrangement of the fluorine atoms around each gold atom. It is the only known dimeric pentafluoride; other pentafluorides are monomeric (P, As, Cl, Br, I), tetrameric (Nb, Ta, Cr, Mo, W, Tc, Re, Ru, Os, Rh, Ir, Pt), or polymeric (Bi, V, U).[1] In the gas phase, a mixture of dimer and trimer in the ratio 82:12 has been observed.
[edit] Synthesis
Gold(V) fluoride can be synthesized by heating gold metal in an atmosphere of oxygen and fluorine to 370 °C under a pressure of 8 atmospheres to form gold dioxygenyl fluoride:[2]
- 2Au(s) + 2O2(g) + 6F2(g) → 2O2AuF6(s)
The complex decomposes at 180 °C to produce the compound:
- 2O2AuF6(s) → 2AuF5(s) + 2O2(g) + F2(g)
[edit] References
- ^ In-Chul Hwang, Konrad Seppelt. Gold Pentafluoride: Structure and Fluoride Ion Affinity. Angewandte Chemie International Edition 2001, 40, 3690-3693. doi:10.1002/1521-3773(20011001)40:19%3C3690::AID-ANIE3690%3E3.0.CO;2-5
- ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements, 2nd Edition, Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.
