Silver(I,III) oxide

Summary

Silver(I,III) oxide or tetrasilver tetraoxide 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]

Silver(I,III) oxide
Silver(I,III) Oxide
Ag(I) Ag(III) O
Names
IUPAC name
silver(I,III) Oxide
Other names
silver peroxide, argentic oxide, silver suboxide, divasil, tetrasilver tetraoxide
Identifiers
  • 1301-96-8 checkY
  • 155645-89-9 https://pubchem.ncbi.nlm.nih.gov/compound/44150047 lists only CAS 155645-89-9. Perhaps the CASNo 1301-96-8 is due to https://patents.justia.com/patent/6645531 (Antelman, year 2000): "Tetrasilver tetroxide compositions... have been commercially sold under the poorly named “Ag(II) OXIDE” tradename. They may be obtained from Aldrich Chemical Co., Inc..."
3D model (JSmol)
  • Interactive image
ECHA InfoCard 100.013.726 Edit this at Wikidata
EC Number
  • 215-098-2
  • 44150047
UNII
  • 4C3LTJ9O6J checkY
  • 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 mark
Danger
H272, H315, H319, H335
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

StructureEdit

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−.

ReferencesEdit

  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.