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Silver(I,III) oxide

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Silver(I,III) oxide
Silver(I,III) Oxide
Ag(I) Ag(III) O
Names
IUPAC name
silver(I,III) Oxide
Other names
tetrasilver tetroxide, silver peroxide, argentic oxide, silver suboxide, divasil
Identifiers
3D model (JSmol)
ECHA InfoCard 100.013.726 Edit this at Wikidata
EC Number
  • 215-098-2
UNII
  • InChI=1S/4Ag.4O
    Key: RARXNJBGGSMBMG-UHFFFAOYSA-N
  • [Ag]O[Ag].O=[Ag]O[Ag]=O
Properties
Ag4O4

Ag2O.Ag2O3

Molar mass 123.87 g/mol
Appearance grey-black powder
diamagnetic
Density 7.48 g/cm3
Melting point >100 °C, decomposition
.0027 g/100 mL
Solubility soluble in alkalis
Hazards
GHS labelling:
GHS03: OxidizingGHS05: CorrosiveGHS07: Exclamation markGHS09: Environmental hazard
Danger
H272, H315, H319, H335
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
3
0
1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Silver(I,III) oxide or tetrasilver tetroxide is the inorganic compound with the formula Ag4O4. It is a component of silver zinc batteries. It can be prepared by the slow addition of a silver(I) salt to a persulfate solution e.g. AgNO3 to a Na2S2O8 solution.[1] It adopts an unusual structure, being a mixed-valence compound.[2] It is a dark brown solid that decomposes with evolution of O2 in water. It dissolves in concentrated nitric acid to give brown solutions containing the Ag2+ ion.[3]

Structure

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Although its empirical formula, AgO, suggests that the compound tetrasilver tetraoxide has silver in the +2 oxidation state, each unit has two monovalent silver atoms bonded to an oxygen atom, and two trivalent silver atoms bonded to three oxygen atoms, and it is in fact diamagnetic. X-ray diffraction studies show that the silver atoms adopt two different coordination environments, one having two collinear oxide neighbours and the other four coplanar oxide neighbours.[1] tetrasilver tetraoxide is therefore formulated as AgIAgIIIO2[4] or Ag2O·Ag2O3. It has previously been called silver peroxide, which is incorrect since it does not contain the peroxide ion, O22−.

Uses

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Tetrasilver tetroxide has been marketed under a trade name "Tetrasil." In 2010, the FDA issued a warning letter to an American company concerning the firm's marketing of Tetrasil and Genisil ointments of tetrasilver tetroxide for herpes and similar conditions.[5]

References

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  1. ^ a b Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN 0-19-855370-6
  2. ^ David Tudela "Silver(II) Oxide or Silver(I,III) Oxide?" J. Chem. Educ., 2008, volume 85, p 863. doi:10.1021/ed085p863
  3. ^ Peter Fischer, Martin Jansen "Electrochemical Syntheses of Binary Silver Oxides" 1995, vol. 30, pp. 50–55. doi:10.1002/9780470132616.ch11
  4. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8. p. 1181.
  5. ^ "FDA Warning Letter to Aidance Skincare and Topical Solutions, LLC | Quackwatch". 19 July 2010.