Phenylarsonic acid
| |||
| Names | |||
|---|---|---|---|
| Preferred IUPAC name
Phenylarsonic acid | |||
| Other names
Benzenearsonic acid | |||
| Identifiers | |||
3D model (JSmol) |
|||
| Abbreviations | PAA | ||
| 2935741 | |||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider | |||
| ECHA InfoCard | 100.002.393 | ||
| EC Number |
| ||
| 131185 | |||
| MeSH | Benzenearsonic+acid | ||
PubChem CID |
|||
| RTECS number |
| ||
| UNII | |||
| UN number | 1557 | ||
CompTox Dashboard (EPA) |
|||
| |||
| |||
| Properties | |||
| C6H7AsO3 | |||
| Molar mass | 202.041 g·mol−1 | ||
| Appearance | Colourless solid | ||
| Density | 1.76 g cm−3 | ||
| Melting point | 154 to 158 °C (309 to 316 °F; 427 to 431 K) | ||
| low | |||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards |
Toxic | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |||
Phenylarsonic acid is the organoarsenic compound with the formula C6H5AsO(OH)2, commonly abbreviated PhAsO3H2. This colourless solid is an organic derivative of arsenic acid, AsO(OH)3, where one OH group has been replaced by a phenyl group. The compound is a precursor to other arylarsonic acids.
Preparation and structure
[edit]PhAsO3H2 can be prepared by several routes. A common method is the "Bart reaction", named for Heinrich Bart, in which phenyldiazonium salts react with sodium arsenite in the presence of a copper catalyst. The method is reminiscent of the Sandmeyer reaction.[1][2]
- C
6H
5N+
2 + NaAsO3H2 → C6H5AsO3H2 + Na+ + N2
Related derivatives are prepared similarly.[3] It was first prepared by August Michaelis.[4][5] X-ray crystallography shows short intermolecular O···O distances of 2.5 Å, consistent with hydrogen bonding. The arsenic center is tetrahedral.[6]
Related phenylarsonic acids
[edit]Several derivatives of phenylarsonic acid were once used as poultry feed additives. These include 4-hydroxy-3-nitrobenzenearsonic acid (3-NHPAA, or Roxarsone), p-arsanilic acid (p-ASA), 4-nitrophenylarsonic acid (nitarsone, 4-NPAA), and p-ureidophenylarsonic acid (carbarsone, p-UPAA). They are now banned in the US and EU.
Further reading
[edit]- A. Michaelis; H. Loesner (1894). "Ueber nitrirte Phenylarsenverbindungen". Berichte der Deutschen Chemischen Gesellschaft. 27: 263–272. doi:10.1002/cber.18940270151.
References
[edit]- ↑ Hamilton, C. S.; Morgan, J. F. (1944). "The Preparation of Aromatic Arsonic and Arsinic Acids by the Bart, Béchamp, and Rosenmund Reactions". Organic Reactions. Vol. 2. pp. 415–454. doi:10.1002/0471264180.or002.10. ISBN 0471264180.
{{cite book}}: ISBN / Date incompatibility (help) - ↑ Bullard, R. H.; Dickey, J. B. (1935). "Phenylarsonic Acid". Organic Syntheses. 15: 59. doi:10.15227/orgsyn.015.0059.
- ↑ Ruddy, A. W.; Starkey, E. B. (1946). "p-Nitrophenylarsonic Acid". Organic Syntheses. 26: 60. doi:10.15227/orgsyn.026.0060.
- ↑ A. Michaelis (1875). "Ueber aromatische Arsenverbindungen". Berichte der Deutschen Chemischen Gesellschaft. 8 (2): 1316–1317. doi:10.1002/cber.187500802125.
- ↑ A. Michaelis; W. La Coste (1880). "Ueber die Verbindungen der Elemente der Stickstoffgruppe mit den Radicalen der aromatischen Reihe. Dritte Abhandlung: Ueber aromatische Arsenverbindungen". Annalen der Chemie. 201 (2–3): 184–261. doi:10.1002/jlac.18802010204.
- ↑ Struchkov, Yu. T. "Crystal and molecular structure of phenylarsonic acid" Russian Chemical Bulletin 1960, Volume 9, 1829-1833. doi:10.1007/BF00907739