Arsenic trifluoride
| |||
| Names | |||
|---|---|---|---|
| IUPAC name
Arsenic(III) fluoride
| |||
| Other names
Arsenic trifluoride, trifluoroarsane
| |||
| Identifiers | |||
3D model (JSmol)
|
|||
| ChemSpider | |||
| ECHA InfoCard | 100.029.145 | ||
PubChem CID
|
|||
| RTECS number |
| ||
CompTox Dashboard (EPA)
|
|||
| |||
| |||
| Properties | |||
| AsF3 | |||
| Molar mass | 131.9168 g/mol | ||
| Appearance | colorless liquid | ||
| Density | 2.666 g/cm3[1] | ||
| Melting point | -8.5 ˚C | ||
| Boiling point | 60.4 ˚C | ||
| decomposes | |||
| Solubility | soluble in alcohol, ether, benzene and ammonia solution | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards
|
Toxic, corrosive | ||
| Thermochemistry | |||
Std enthalpy of
formation (ΔfH⦵298) |
-821.3 kJ/mol | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |||
fluoride.svg)
Arsenic trifluoride is a chemical compound of arsenic and fluorine with the formula AsF3. It is a colorless liquid which reacts readily with water.[2]
Preparation and properties
It can be prepared by reacting hydrogen fluoride, HF, with arsenic trioxide:[2]
- 6HF + As2O3 → 2AsF3 + 3H2O
It has a pyramidal molecular structure in the gas phase which is also present in the solid.[2] In the gas phase the As-F bond length is 170.6 pm and the F-As-F bond angle 96.2°.[3]
Arsenic trifluoride is used as fluorinating non-metal chlorides to fluorides, in this respect it is less reactive than SbF3.[2]
Salts containing AsF4− anion can be prepared for example CsAsF4.[4] the potassium salt KAs2F7 prepared from KF and AsF3 contains AsF4− and AsF3 molecules with evidence of interaction between the AsF3 molecule and the anion.[5]
With SbF5 the ionic adduct AsF2+ SbF6− is produced [6]
References
- ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0070494398
- ^ a b c d Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
- ^ Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6
- ^ New alkali metal and tetramethylammonium tetrafluoroarsenates(III), their vibrational spectra and crystal structure of cesium tetrafluoroarsenate(III)Klampfer P, Benkič P, Lesar A, Volavšek B, Ponikvar M , Jesih A., Collect. Czech. Chem. Commun. 2004, 69, 339-350 doi:10.1135/cccc20040339
- ^ Alkali-metal heptafluorodiarsenates(III): their preparation and the crystal structure of the potassium salt, Edwards A.J., Patel S.N., J. Chem. Soc., Dalton Trans., 1980, 1630-1632, doi:10.1039/DT9800001630
- ^ Fluoride crystal structures. Part XV. Arsenic trifluoride–antimony pentafluoride, Edwards A. J., Sills R. J. C. J. Chem. Soc. A, 1971, 942 - 945, doi:10.1039/J19710000942