Antimony trifluoride is the

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistr ...

with the formula SbF₃. Sometimes called Swarts' reagent, is one of two principal

fluoride Fluoride (). According to this source, is a possible pronunciation in British English. is an inorganic, monatomic anion of fluorine, with the chemical formula (also written ), whose salts are typically white or colorless. Fluoride salts ty ...

s of antimony, the other being SbF₅. It appears as a white solid. As well as some industrial applications, it is used as a reagent in inorganic and

organofluorine chemistry Organofluorine chemistry describes the chemistry of the organofluorines, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil and water repellents to pharmaceuticals, re ...

Preparation and structure

In solid SbF₃, the Sb centres have

octahedral molecular geometry In chemistry, octahedral molecular geometry, also called square bipyramidal, describes the shape of compounds with six atoms or groups of atoms or ligands symmetrically arranged around a central atom, defining the vertices of an octahedron. The oc ...

and are linked by bridging fluoride ligands. Three Sb–F bonds are short (192 pm) and three are long (261 pm). Because it is a polymer, SbF₃ is far less volatile than related compounds AsF₃ and SbCl₃. SbF₃ is prepared by treating

antimony trioxide Antimony(III) oxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite. Like most polymeric oxides, Sb2O3 dissolves in ...

with hydrogen fluoride: :Sb₂O₃ + 6 HF → 2 SbF₃ + 3 H₂O The compound is a mild

Lewis acid A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any sp ...

, hydrolyzing slowly in water. With fluorine, it is oxidized to give

antimony pentafluoride Antimony pentafluoride is the inorganic compound with the formula Sb F5. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, formed when mixing liquid HF with liquid SbF5 in a 2:1 ratio. ...

. :SbF₃ + F₂ → SbF₅

Applications

It is used as a

fluorination In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers ...

reagent in organic chemistry. This application was reported by the Belgian chemist Frédéric Jean Edmond Swarts in 1892, who demonstrated its usefulness for converting chloride compounds to

s. The method involved treatment with antimony trifluoride with

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is ...

or with antimony pentachloride to give the active species antimony trifluorodichloride (SbCl₂F₃). This compound can also be produced in bulk. The

Swarts reaction Swarts fluorination is a process whereby the chlorine atoms in a compound – generally an organic compound, but experiments have been performed using silanes – are replaced with fluorine, by treatment with antimony trifluoride in the presence ...

is generally applied to the synthesis of

organofluorine compound Organofluorine chemistry describes the chemistry of the organofluorines, organic compounds that contain the carbon–fluorine bond. Organofluorine compounds find diverse applications ranging from oil and water repellents to pharmaceuticals, refri ...

s, but experiments have been performed using

silane Silane is an inorganic compound with chemical formula, . It is a colourless, pyrophoric, toxic gas with a sharp, repulsive smell, somewhat similar to that of acetic acid. Silane is of practical interest as a precursor to elemental silicon. Sila ...

s. It was once used for the industrial production of freon. Other fluorine-containing

Lewis acids A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any s ...

serve as fluorinating agents in conjunction with hydrogen fluoride. SbF₃ is used in dyeing and in pottery, to make ceramic enamels and glazes.

Safety

The lethal minimum dose (guinea pig, oral) is 100 mg/kg.Sabina C. Grund, Kunibert Hanusch, Hans J. Breunig, Hans Uwe Wolf “Antimony and Antimony Compounds” in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim.

References

External links

WebBook page for SbF3
{{DEFAULTSORT:Antimony Trifluoride Antimony(III) compounds Fluorides Metal halides Fluorinating agents