Arsenic trifluoride
| |||
| Names | |||
|---|---|---|---|
| IUPAC name
Arsenic(III) fluoride | |||
| Other names
Arsenic trifluoride, trifluoroarsane | |||
| Identifiers | |||
| 7784-35-2 | |||
| 3D model (Jmol) | Interactive image | ||
| ChemSpider | 22975 | ||
| ECHA InfoCard | 100.029.145 | ||
| PubChem | 24571 | ||
| RTECS number | CG5775000 | ||
| |||
| |||
| Properties | |||
| AsF3 | |||
| Molar mass | 131.9168 g/mol | ||
| Appearance | colorless liquid | ||
| Density | 2.666 g/cm3[1] | ||
| Melting point | −8.5 °C (16.7 °F; 264.6 K) | ||
| Boiling point | 60.4 °C (140.7 °F; 333.5 K) | ||
| decomposes | |||
| Solubility | soluble in alcohol, ether, benzene and ammonia solution | ||
| Hazards | |||
| Main hazards | Toxic, corrosive | ||
| R-phrases | R23/25, R50/53 | ||
| S-phrases | (S1/2), S20/21, S28, S45, S60, S61 | ||
| US health exposure limits (NIOSH): | |||
| PEL (Permissible) |
[1910.1018] TWA 0.010 mg/m3[2] | ||
| REL (Recommended) |
Ca C 0.002 mg/m3 [15-minute][2] | ||
| IDLH (Immediate danger) |
Ca [5 mg/m3 (as As)][2] | ||
| Thermochemistry | |||
| Std enthalpy of formation (ΔfH |
-821.3 kJ/mol | ||
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |||
 verify (what is  ?) | |||
| Infobox references | |||
fluoride.svg.png)
Arsenic trifluoride is a chemical compound of arsenic and fluorine with the chemical formula AsF3. It is a colorless liquid which reacts readily with water.[3]
Preparation and properties
It can be prepared by reacting hydrogen fluoride, HF, with arsenic trioxide:[3]
- 6HF + As2O3 → 2AsF3 + 3H2O
It has a pyramidal molecular structure in the gas phase which is also present in the solid.[3] In the gas phase the As-F bond length is 170.6 pm and the F-As-F bond angle 96.2°.[4]
Arsenic trifluoride is used as fluorinating non-metal chlorides to fluorides, in this respect it is less reactive than SbF3.[3]
Salts containing AsF4− anion can be prepared for example CsAsF4.[5] 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.[6]
With SbF5 the ionic adduct AsF2+ SbF6− is produced [7]
References
- ↑ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
- 1 2 3 "NIOSH Pocket Guide to Chemical Hazards #0038". National Institute for Occupational Safety and Health (NIOSH).
- 1 2 3 4 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.
- ↑ 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