Antimony trifluoride

Antimony trifluoride is the inorganic compound with the formula SbF₃. Sometimes called Swarts' reagent, it is one of two principal fluorides of antimony, the other being SbF₅. It appears as a white solid. As well as some industrial applications,^[2] it is used as a reagent in inorganic and organofluorine chemistry.

Antimony trifluoride

Structural formula space-filling model
Unit cell Unit cell of antimony trifluoride. The distorted-octahedral coordination of the fluorine relative to the antimony is visualized.
Names
Preferred IUPAC name Antimony(III) fluoride
Systematic IUPAC name Trifluorostibane
Other names Trifluoroantimony
Identifiers
CAS Number	7783-56-4 Y
3D model (JSmol)	Interactive image
ChemSpider	22960 Y
ECHA InfoCard	100.029.099
EC Number	232-009-2
PubChem CID	24554
RTECS number	CC5150000
UNII	VWM00O92AM Y
UN number	UN 2923
CompTox Dashboard (EPA)	DTXSID1064827
InChI InChI=1S/3FH.Sb/h3*1H;/q;;;+3/p-3 Y Key: GUNJVIDCYZYFGV-UHFFFAOYSA-K Y InChI=1S/3FH.Sb/h3*1H;/q;;;+3/p-3 Key: GUNJVIDCYZYFGV-UHFFFAOYSA-K InChI=1/3FH.Sb/h3*1H;/q;;;+3/p-3 Key: GUNJVIDCYZYFGV-DFZHHIFOAW
SMILES F[Sb](F)F
Properties
Chemical formula	SbF3
Molar mass	178.76 g/mol
Appearance	light gray to white crystals
Odor	pungent
Density	4.379 g/cm3
Melting point	292 °C (558 °F; 565 K)
Boiling point	376 °C (709 °F; 649 K)
Solubility in water	385 g/100 mL (0 °C) 443 g/100 mL (20 °C) 562 g/100 mL (30 °C)
Solubility	soluble in methanol, acetone insoluble in ammonia
Magnetic susceptibility (χ)	-46.0·10−6 cm3/mol
Structure
Crystal structure	Orthorhombic, oS16
Space group	Ama2, No. 40
Hazards
NFPA 704 (fire diamond)	3 0 0
Lethal dose or concentration (LD, LC):
LD50 (median dose)	100 mg/kg
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 0.5 mg/m3 (as Sb)[1]
REL (Recommended)	TWA 0.5 mg/m3 (as Sb)[1]
Related compounds
Related compounds	antimony pentafluoride, antimony trichloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation and structure

In solid SbF₃, the Sb centres have octahedral molecular geometry 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.^[3]

SbF₃ is prepared by treating antimony trioxide with hydrogen fluoride:^[4]

Sb₂O₃ + 6 HF → 2 SbF₃ + 3 H₂O

The compound is a mild Lewis acid, hydrolyzing slowly in water. With fluorine, it is oxidized to give antimony pentafluoride.

SbF₃ + F₂ → SbF₅

Applications

It is used as a fluorination reagent in organic chemistry.^[5] This application was reported by the Belgian chemist Frédéric Jean Edmond Swarts in 1892,^[6] who demonstrated its usefulness for converting chloride compounds to fluorides. The method involved treatment with antimony trifluoride with chlorine or with antimony pentachloride to give the active species antimony trifluorodichloride (SbCl₂F₃). This compound can also be produced in bulk.^[7] The Swarts reaction is generally applied to the synthesis of organofluorine compounds, but experiments have been performed using silanes.^[8] It was once used for the industrial production of freon. Other fluorine-containing Lewis acids 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.^[9]

References

1. NIOSH Pocket Guide to Chemical Hazards. "#0036". National Institute for Occupational Safety and Health (NIOSH).
2. 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. doi:10.1002/14356007.a03_055.pub2
3. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
4. Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 199.
5. Tariq Mahmood and Charles B. Lindahl Fluorine Compounds, Inorganic, Antimony in Kirk‑Othmer Encyclopedia of Chemical Technology.doi:10.1002/0471238961.0114200913010813.a01
6. Swarts (1892). Acad. Roy. Belg. 3 (24): 474.{{cite journal}}: CS1 maint: untitled periodical (link)
7. US 4438088
8. Booth, Harold Simmons; Suttle, John Francis (1946). "IV. The Preparation and Fluorination of Dimethyl and Trimethyl Chlorosilanes". J. Am. Chem. Soc. 68 (12): 2658–2660. doi:10.1021/ja01216a072.
9. 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. doi:10.1002/14356007.a03_055.pub2

External links

• WebBook page for SbF3