Names | |
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IUPAC name
Potassium nitrosodisulfonate
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Identifiers | |
3D model (
JSmol)
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ChemSpider | |
ECHA InfoCard | 100.034.729 |
EC Number |
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PubChem
CID
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UNII | |
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Properties | |
K2NO(SO3)2 | |
Molar mass | 268.33 g/mol (potassium salt) |
Appearance | Yellowish-brown solid |
Hazards | |
GHS labelling: | |
Danger | |
H260, H302, H312, H332 | |
P223, P231+P232, P280, P301+P312, P302+P352+P312, P304+P340+P312 | |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Frémy's salt is a chemical compound with the formula (K4[ON(SO3)22), sometimes written as (K2[NO(SO3)2]). It is a bright yellowish-brown solid, but its aqueous solutions are bright violet. [1] [2] The related sodium salt, disodium nitrosodisulfonate (NDS, Na2ON(SO3)2, CAS 29554-37-8) is also referred to as Frémy's salt. [3]
Regardless of the cations, the salts are distinctive because aqueous solutions contain the radical [ON(SO3)22−.
Frémy's salt, being a long-lived free radical, is used as a standard in electron paramagnetic resonance (EPR) spectroscopy, e.g. for quantitation of radicals. Its intense EPR spectrum is dominated by three lines of equal intensity with a spacing of about 13 G (1.3 mT). [4] [5] [6]
The inorganic aminoxyl group is a persistent radical, akin to TEMPO.
It has been used in some oxidation reactions, such as for oxidation of some anilines and phenols [7] [8] [9] [10] [11] allowing polymerization and cross-linking of peptides and peptide-based hydrogels. [12] [13]
It can also be used as a model for peroxyl radicals in studies that examine the antioxidant mechanism of action in a wide range of natural products. [14]
Frémy's salt is prepared from hydroxylaminedisulfonic acid. Oxidation of the conjugate base gives the purple dianion:
The synthesis can be performed by combining nitrite and bisulfite to give the hydroxylaminedisulfonate. Oxidation is typically conducted at low-temperature, either chemically or by electrolysis. [3] [2]
Other reactions:
Frémy's salt was discovered in 1845 by Edmond Frémy (1814–1894). [15] Its use in organic synthesis was popularized by Hans Teuber, such that an oxidation using this salt is called the Teuber reaction. [9] [10]
Names | |
---|---|
IUPAC name
Potassium nitrosodisulfonate
| |
Identifiers | |
3D model (
JSmol)
|
|
ChemSpider | |
ECHA InfoCard | 100.034.729 |
EC Number |
|
PubChem
CID
|
|
UNII | |
| |
| |
Properties | |
K2NO(SO3)2 | |
Molar mass | 268.33 g/mol (potassium salt) |
Appearance | Yellowish-brown solid |
Hazards | |
GHS labelling: | |
Danger | |
H260, H302, H312, H332 | |
P223, P231+P232, P280, P301+P312, P302+P352+P312, P304+P340+P312 | |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Frémy's salt is a chemical compound with the formula (K4[ON(SO3)22), sometimes written as (K2[NO(SO3)2]). It is a bright yellowish-brown solid, but its aqueous solutions are bright violet. [1] [2] The related sodium salt, disodium nitrosodisulfonate (NDS, Na2ON(SO3)2, CAS 29554-37-8) is also referred to as Frémy's salt. [3]
Regardless of the cations, the salts are distinctive because aqueous solutions contain the radical [ON(SO3)22−.
Frémy's salt, being a long-lived free radical, is used as a standard in electron paramagnetic resonance (EPR) spectroscopy, e.g. for quantitation of radicals. Its intense EPR spectrum is dominated by three lines of equal intensity with a spacing of about 13 G (1.3 mT). [4] [5] [6]
The inorganic aminoxyl group is a persistent radical, akin to TEMPO.
It has been used in some oxidation reactions, such as for oxidation of some anilines and phenols [7] [8] [9] [10] [11] allowing polymerization and cross-linking of peptides and peptide-based hydrogels. [12] [13]
It can also be used as a model for peroxyl radicals in studies that examine the antioxidant mechanism of action in a wide range of natural products. [14]
Frémy's salt is prepared from hydroxylaminedisulfonic acid. Oxidation of the conjugate base gives the purple dianion:
The synthesis can be performed by combining nitrite and bisulfite to give the hydroxylaminedisulfonate. Oxidation is typically conducted at low-temperature, either chemically or by electrolysis. [3] [2]
Other reactions:
Frémy's salt was discovered in 1845 by Edmond Frémy (1814–1894). [15] Its use in organic synthesis was popularized by Hans Teuber, such that an oxidation using this salt is called the Teuber reaction. [9] [10]