silver(I,III) oxide

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| Watchedfields = changed

| verifiedrevid = 442841576

| ImageFile = AgO-monoclinic-xtal-2x2x2-oxcol-3D-bs-17.png

| ImageSize =

| ImageName = Silver(I,III) Oxide

| ImageCaption = {{Colorsample2|#cbcbcb}} Ag(I) {{Colorsample2|#929292}} Ag(III) {{Colorsample2|red}} O

| IUPACName = silver(I,III) Oxide

| OtherNames = tetrasilver tetroxide, silver peroxide, argentic oxide, silver suboxide, divasil

| Section1 = {{Chembox Identifiers

| CASNo = 1301-96-8

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo1 = 155645-89-9

| CASNo1_Comment = 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..."

| ChemSpiderID =

| EINECS = 215-098-2

| PubChem = 44150047

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 4C3LTJ9O6J

| SMILES = [Ag]O[Ag].O=[Ag]O[Ag]=O

| StdInChI = 1S/4Ag.4O

| StdInChIKey = RARXNJBGGSMBMG-UHFFFAOYSA-N

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| Section2 = {{Chembox Properties

| Formula = Ag4O4

Ag2O.Ag2O3

| MolarMass = 123.87 g/mol

| Appearance = grey-black powder
diamagnetic

| Density = 7.48 g/cm3

| MeltingPt =>100 °C, decomposition

| BoilingPt =

| Solubility = .0027 g/100 mL

| SolubleOther = soluble in alkalis

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| Section7 = {{Chembox Hazards

| GHSPictograms = {{GHS03}}{{GHS05}}{{GHS07}}{{GHS09}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|272|315|319|335}}

| PPhrases = {{P-phrases|}}

| NFPA-H = 3

| NFPA-F = 0

| NFPA-I = 1

| NFPA-S =

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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. It adopts an unusual structure, being a mixed-valence compound.David Tudela "Silver(II) Oxide or Silver(I,III) Oxide?" J. Chem. Educ., 2008, volume 85, p 863. {{doi| 10.1021/ed085p863}} 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. Peter Fischer, Martin Jansen "Electrochemical Syntheses of Binary Silver Oxides" 1995, vol. 30, pp. 50–55. {{doi|10.1002/9780470132616.ch11}}

Structure

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.Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications {{ISBN|0-19-855370-6}} tetrasilver tetraoxide is therefore formulated as AgIAgIIIO2{{Greenwood&Earnshaw}} p. 1181. or Ag2O·Ag2O3. It has previously been called silver peroxide, which is incorrect since it does not contain the peroxide ion, O22−.

Uses

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.{{cite web | url=https://quackwatch.org/cases/fdawarning/prod/fda-warning-letters-about-products-2008/aidance/ | title=FDA Warning Letter to Aidance Skincare and Topical Solutions, LLC | Quackwatch | date=19 July 2010 }}

References

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Category:Silver compounds

Category:Mixed valence compounds

Category:Transition metal oxides