Roussin's black salt

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Name = Roussin's Black Salt‎| ImageFile = Structure_of_Roussin's_Black_Salt.png‎ ImageFile1 = Roussin's-black-salt-anion-3D-balls.png IUPACName =
OtherNames = Sodium heptanitrosyltri-μ3-thiotetraferrate
Section1 = Chembox Identifiers
CASNo = 12518-87-5
Section2 = Chembox Properties
Formula = Fe₄N₇NaO₇S₃
MolarMass = 552.67 g/mol
Appearance = Black needles
Density =
Solubility =
MeltingPt = 198-200 °C (471-473 K)
BoilingPt =
Section7 = Chembox Hazards
ExternalMSDS =
NFPA-H =
NFPA-F =
NFPA-R =
FlashPt =
Section8 = Chembox Related
OtherFunctn = Roussin's Red Salt

Roussin's Black Salt is a chemical compound with the formula NaFe₄S₃(NO)₇. It is classified as metal nitrosyl compound. It consists of the sodium salt of the [Fe₄S₃(NO)₇] ⁻ anion. The geometry of the anion cluster is that of an incomplete cubane. The point group symmetry of the anion is "C"_3v.

ynthesis

Roussin’s Black Salt is produced by the reaction of nitrous acid, potassium hydroxide, potassium sulfide, and iron(II) sulfate in aqueous solution. [L. Marchlewski; J. Sacks. “Studien über Roussins Salz.” "Z. Anorg. Chem." 1892, "2", 175–181.] It can also be formed by the conversion of Roussin's Red Salt in mildly acidic conditions. This reaction is reversible and Roussin’s Red Salt is reformed upon alkalization of the reaction solution.

Uses

Roussin’s Black Salt is a nitric oxide donor. The nitric oxide donated by Roussin’s Black Salt has proven to be toxic to some melanoma cancer cells. [Janczyk, A.; "et al". "NO-dependent phototoxicity of Roussin’s black salt against cancer cells." "Nitric Oxide", 2004, "10", 42-50.] Also, Roussin’s Black Salt demonstrates antibacterial activity in some food processing applications. [Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann]

ee also

* Roussin's Red Salt

References

General references

* Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4.

* Roussin, M.L. "Ann. Chim. Phys" 1858, "3", 285.