Cobalt(II,III) oxide

Cobalt(II,III) oxide^[1]

Names
IUPAC name cobalt(II) dicobalt(III) oxide
Other names cobalt oxide, cobalt(II,III) oxide, cobaltosic oxide, tricobalt tetroxide
Identifiers
CAS Number	1308-06-1
ChemSpider	9826389
Jmol interactive 3D	Image
PubChem	11651651
RTECS number	GG2500000
InChI InChI=1S/3Co.4O Key: LBFUKZWYPLNNJC-UHFFFAOYSA-N InChI=1/3Co.4O/rCo2O3.CoO/c3-1-5-2-4;1-2 Key: LBFUKZWYPLNNJC-PMPQCLQHAA
SMILES [Co]=O.O=[Co]O[Co]=O
Properties
Chemical formula	Co3O4 CoO.Co2O3
Molar mass	240.80 g/mol
Appearance	black solid
Density	6.11 g/cm^3
Melting point	895 °C (1,643 °F; 1,168 K)
Boiling point	900 °C (1,650 °F; 1,170 K) (decomposes)
Solubility in water	Insoluble
Solubility	soluble in acids and alkalis
Structure
Crystal structure	cubic
Hazards
R-phrases	R40 R41 R42 R43
S-phrases	S36/37
NFPA 704	0 2 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
verify (what is  ?)
Infobox references

Cobalt(II,III) oxide is inorganic compound with the formula Co₃O₄. It is one of two well characterized cobalt oxides. It is a black antiferromagnetic solid. As a mixed valence compound, its formula is sometimes written as Co^IICo^III₂O₄ and sometimes as CoO•Co₂O₃.^[2]

Structure

Co₃O₄ adopts the normal spinel structure, with Co²⁺ ions in tetrahedral interstices and Co³⁺ ions in the octahedral interstices of the cubic close-packed lattice of oxide anions.^[2]

tetrahedral coordination geometry of Co(II)	distorted octahedral coordination geometry of Co(III)	distorted tetrahedral coordination geometry of O

Synthesis

Cobalt(II) oxide, CoO, converts to Co₃O₄ if heated to around 600-700 °C in air.^[3] Above 900 °C, CoO is stable.^[3][4] These reaction are described by the following equilibrium:

2 Co₃O₄ $\overrightarrow{\leftarrow}$ 6 CoO + O₂

Research

This inorganic compound is currently utilized in the process of artificial photosynthesis.

Safety

Cobalt compounds are potentially poisonous in large amounts.^[5]

See also

• Cobalt Oxide Nanoparticles

References

1. Sigma-Aldrich product page
2. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1118. ISBN 0-08-037941-9.
3. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1118. ISBN 0-08-037941-9.
4. Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. p. 1520.
5. MSDS