Fremy's salt
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Fremy's salt | |
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IUPAC name | Potassium nitrosodisulfonate |
Identifiers | |
CAS number | [14293-70-0 (Potassium salt)] |
PubChem | |
Properties | |
Molecular formula | (KSO3)2NO (Potassium salt) |
Molar mass | 268.33 g/mol (Potassium salt) |
Hazards | |
Main hazards | Harmful (Xn) |
R-phrases | R14 R20/21/22 |
S-phrases | S36 |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Fremy's salt, discovered in 1845 by Edmond Fremy (1814 - 1894), is a chemical compound and a strong oxidizing agent. The formal name is disodium nitrosodisulfonic acid or NO(SO3Na)2 but Fremy's salt refers equally well to the potassium salt potassium nitrosodisulfonate.
[edit] Properties and reactions
The nitroso compound is a persistent organic radical like TEMPO. It is especially useful in oxidations of phenols to hydroquinones in the Teuber reaction.
[edit] Preparation
The salt can be prepared from sodium nitrite, sodium bicarbonate and sulfur dioxide to disodium hydroxylaminedisulfonate and carbon dioxide followed by one-electron oxidation by electrolysis in a basic solution.
[edit] References
- H.-J. Teuber and S. Benz, Chem. Ber., 100, 2918, 1967.