Antimony pentafluoride
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Antimony pentafluoride, also known as antimony(V) fluoride, is a chemical compound made of antimony and fluorine. Its chemical formula is SbF5. It has five antimony-fluorine bonds. The antimony is in its +5 oxidation state.
Properties
[change | change source]Antimony pentafluoride is a colorless, viscous fuming liquid (at 25 degrees Celsius at standard atmosphere, a pressure). It is an extremely powerful oxidizing and fluorinating agent and very reactive. Sodium, potassium and phosphorus (red or yellow) can burn on contact with it. It can oxidize oxygen in the present of fluorine, which makes SbF5·F2 one of the strongest oxidizers. It is not normal as oxygen normally oxidizes other things; it does not get oxidized commonly. It can make extremely strong acids (fluoroantimonic acid) when mixed with hydrogen fluoride. It was used in the first reaction that used fluorides to make fluorine.
Antimony pentafluoride is a Lewis acid, because the antimony atom can accept a lone pair of electrons from another molecule. The high Lewis acidity of SbF5 allows it to be mixed with strong Brønsted acids to make superacids. Examples of SbF5 superacids include fluoroantimonic acid (HF·SbF5) and magic acid (HSO3F·SbF5).
Preparation
[change | change source]It is made by reacting antimony pentoxide or antimony pentachloride with hydrofluoric acid. It can also be made by reacting antimony trifluoride with fluorine.
Uses
[change | change source]Antimony pentafluoride is mostly used to make superacids for research. It can also produce fluoroantimonates, a family of weakly coordinating anions, from a source of fluoride.
It was also used in the first chemical reaction that made fluorine gas from fluorine compounds. This reaction is not widely used, as fluorine is normally made by electrolysis.
Safety
[change | change source]Antimony pentafluoride is a component of the strongest acids in the world. It reacts with most chemical compounds. It is extremely corrosive and hazardous to health. It is one of the most poisonous known chemicals by volume. It is a notoriously powerful oxidizer and should be kept away from combustible materials. It violently forms Hydrogen Fluoride in contact with water and biological tissues. It's one of the most hazardous substances known, as mentioned in the EPA list of extremely hazardous substances.