Antimony pentafluoride
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| Names | |||
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IUPAC name
antimony(V) fluoride
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| Other names
antimony pentafluoride
pentafluoridoantimony |
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| Identifiers | |||
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3D model (Jmol)
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| ChemSpider | |||
| ECHA InfoCard | 100.029.110 | ||
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PubChem CID
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| RTECS number | CC5800000 | ||
| UN number | 1732 | ||
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| Properties | |||
| SbF5 | |||
| Molar mass | 216.74 g/mol | ||
| Appearance | colorless oily liquid hygroscopic |
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| Odor | pungent | ||
| Density | 2.99 g/cm3 | ||
| Melting point | 8.3 °C (46.9 °F; 281.4 K) | ||
| Boiling point | 149.5 °C (301.1 °F; 422.6 K) | ||
| Reacts | |||
| Solubility | soluble in KF, liquid SO2 | ||
| Hazards | |||
| Safety data sheet | ICSC 0220 | ||
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EU classification (DSD)
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Harmful (Xn) Dangerous for the environment (N) |
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| R-phrases | R20/22, R51/53 | ||
| S-phrases | (S2), S61 | ||
| NFPA 704 | |||
| US health exposure limits (NIOSH): | |||
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PEL (Permissible)
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TWA 0.5 mg/m3 (as Sb) | ||
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REL (Recommended)
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TWA 0.5 mg/m3 (as Sb) | ||
| Related compounds | |||
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Other anions
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Antimony pentachloride | ||
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Other cations
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Phosphorus pentafluoride Arsenic pentafluoride Bismuth pentafluoride |
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Related compounds
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Antimony trifluoride | ||
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 (what is   ?) |
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| Infobox references | |||
Antimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, the strongest known acid. It is notable for its Lewis acidity and its ability to react with almost all known compounds.
Antimony pentafluoride is prepared by the reaction of antimony pentachloride with anhydrous hydrogen fluoride:
It can also be prepared from antimony trifluoride and fluorine.
In the gas phase, SbF5 adopts a trigonal bipyramidal structure of D3hpoint group symmetry (see picture). The material adopts a more complicated structure in the liquid and solid states. The liquid contains polymers wherein each Sb is octahedral, the structure being described with the formula [SbF4(μ-F)2]n ((μ-F) denotes the fact that fluoride centres bridge two Sb centres). The crystalline material is a tetramer, meaning that it has the formula [SbF4(μ-F)]4. The Sb-F bonds are 2.02 Å within the eight-membered Sb4F4 ring; the remaining fluoride ligands radiating from the four Sb centers are shorter at 1.82 Å. The related species PF5 and AsF5 are monomeric in the solid and liquid states, probably due to the smaller sizes of the central atom, which limits their coordination number. BiF5 is a polymer.
In the same way that SbF5 enhances the Brønsted acidity of HF, it augments the oxidizing power of F2. This effect is illustrated by the oxidation of oxygen:
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