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| Names | |||
|---|---|---|---|
| IUPAC name Antimony pentafluoride | |||
| Systematic IUPAC name Pentafluoro-λ5-stibane | |||
| Other names Antimony(V) fluoride pentafluoridoantimony | |||
| Identifiers | |||
3D model (JSmol) | |||
| ChEBI | |||
| ChemSpider |
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| ECHA InfoCard | 100.029.110 | ||
| EC Number |
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| RTECS number |
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| UNII | |||
| UN number | 1732 | ||
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| Properties | |||
| SbF5 | |||
| Molar mass | 216.74 g/mol | ||
| Appearance | colorless oily, viscous liquid hygroscopic | ||
| Odor | pungent, sharp | ||
| Density | 2.99 g/cm3[1] | ||
| 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 inKF, liquidSO2 | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards | Extremely toxic, corrosive, hazardous to health. Releaseshydrofluoric acid upon contact withwater and biological tissues. Strongoxidizing agent. | ||
| GHS labelling: | |||
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| Danger | |||
| H300+H310+H330,H314,H411,H412 | |||
| P260,P264,P270,P271,P273,P280,P301+P312,P301+P330+P331,P303+P361+P353,P304+P312,P304+P340,P305+P351+P338,P310,P312,P321,P330,P363,P391,P405,P501 | |||
| NFPA 704 (fire diamond) | |||
| Flash point | noncombustible | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose) | 270 mg/kg (mouse, subcutaneous) | ||
LC50 (median concentration) | 270 mg/m3 or 30 ppm (mouse, inhalation) | ||
LCLo (lowest published) | 15 mg/m3 or 1.69 ppm (rat, inhalation, 2 hours) | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) | TWA 0.5 mg/m3 or 0.05 ppm (as Sb)[2] | ||
REL (Recommended) | TWA 0.5 mg/m3 or 0.05 ppm (as Sb)[2] | ||
IDLH (Immediate danger) | 50 mg/m3 (5 ppm) | ||
| Safety data sheet (SDS) | ICSC 0220 | ||
| Related compounds | |||
Otheranions | Antimony pentachloride | ||
Othercations | Phosphorus pentafluoride Arsenic pentafluoride Bismuth pentafluoride | ||
Related compounds | Antimony trifluoride | ||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Antimony pentafluoride is theinorganic compound with the formulaSbF5. This colorless, viscous liquid is a strongLewis acid and a component of thesuperacidfluoroantimonic acid, formed upon mixing liquidHF with liquid SbF5 in a 1:1 molar ratio. It is notable for its strong Lewis acidity and the ability to react with almost all known compounds.[4]
Antimony pentafluoride is prepared by the reaction ofantimony pentachloride with anhydroushydrogen fluoride:[5]
It can also be prepared fromantimony trifluoride andfluorine.[6]
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 centresbridge two Sb centers). 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.[7] The related speciesPF5 andAsF5 aremonomeric 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.[8]
Antimony pentafluoride is a very strong oxidizing agent. Phosphorus burns on contact with it.
SbF5 increases the oxidizing power of Fluorine, making it able to oxidizeoxygen:
SbF5 has also been used in the first discovered chemical reaction that producesfluorine gas from fluoride compounds:
The driving force for this reaction is the high affinity of SbF5 forF−, which is the same property that recommends the use of SbF5 to generate superacids.
SbF5 is a strong Lewis acid, exceptionally so toward sources of F− to give the very stable anion [SbF6]−, called hexafluoroantimonate. It is theconjugate base of the superacidfluoroantimonic acid. [SbF6]− is aweakly coordinating anion akin toPF6−. Although it is only weakly basic, [SbF6]− does react with additional SbF5 to give a centrosymmetricadduct:
The [Sb2F11]− anion is one of the ions found in HF/SbF5 Mixture.
SbF5 is highly corrosive to the skin and the eyes. It is extremely toxic and hazardous to health. Itslethal dose (LD50) is reported to be 270 mg/kg (mouse, subcutaneous) withlowest concentration (LCLo) of 15 mg/m3 or 1.69 ppm (rat, inhalation, 2 hours). Occupational exposure limit set byNIOSH stands at 50 mg/m3 (5 ppm). It is considered to beImmediately dangerous to life and health at this concentration. Other than that, SbF5 reacts violently with water along with many other compounds, often releasing dangeroushydrogen fluoride. It is a very strong oxidizer.[9][10]
