Antimony tetroxide

Antimony tetroxide

     Sb      O
Names
IUPAC name
antimony(III,V) oxide
Identifiers
ECHA InfoCard 100.032.554
Properties
SbO2; Sb2O4
Molar mass 153.7588; 307.5176 g/mol
Appearance white solid
Density 6.64 g/cm3 (orthorhombic form) [1]
Melting point > 930 °C (1,710 °F; 1,200 K) (decomposes)
Boiling point decomposes
insoluble
2.0
Structure
orthorhombic
Hazards
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
1
2
0
US health exposure limits (NIOSH):
PEL (Permissible)
 TWA 0.5 mg/m3 (as Sb)[2]
REL (Recommended)
 TWA 0.5 mg/m3 (as Sb)[2]
Related compounds
Related compounds
 Antimony trioxide
Antimony pentoxide
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

Antimony tetroxide is an inorganic compound with the formula Sb2O4. This material, which exists as the mineral cervantite,[3] is white but reversibly yellows upon heating. The material, with empirical formula SbO2, is called antimony tetroxide to signify the presence of two kinds of Sb centers.

Formation and structure

The material forms when Sb2O3 is heated in air:[4]

Sb2O3 + 0.5 O2 → Sb2O4 ΔH = −187 kJ/mol

At 800 °C, antimony(V) oxide loses oxygen to give the same material:

Sb2O5 → Sb2O4 + 0.5 O2 ΔH = −64 kJ/mol

The material is mixed valence, containing both Sb(V) and Sb(III) centers. Two polymorphs are known, one orthorhombic (shown in the infobox) and one monoclinic.[1] Both forms feature octahedral Sb(V) centers arranged in sheets with distorted Sb(III) centers bound to four oxides.

References

  1. 1 2 Amador, J.; Puebla, E. Gutierrez; Monge, M. A.; Rasines, I.; Valero, C. Ruiz (1988). "Diantimony Tetraoxides Revisited". Inorganic Chemistry. 27: 1367–1370. doi:10.1021/ic00281a011.
  2. 1 2 "NIOSH Pocket Guide to Chemical Hazards #0036". National Institute for Occupational Safety and Health (NIOSH).
  3. ↑ "Cervantite". Webminerals. Retrieved 2009-06-06.
  4. ↑ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
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