Cobalt(II,III) oxide

Cobalt(II,III) oxide
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 Y
PubChem	11651651
ChemSpider	9826389 Y
RTECS number	GG2500000
Jmol-3D images	Image 1
SMILES [Co]=O.O=[Co]O[Co]=O
InChI InChI=1S/3Co.4O Y Key: LBFUKZWYPLNNJC-UHFFFAOYSA-N Y InChI=1/3Co.4O/rCo2O3.CoO/c3-1-5-2-4;1-2 Key: LBFUKZWYPLNNJC-PMPQCLQHAA
Properties
Molecular formula	Co3O4 CoO.Co2O3
Molar mass	240.80 g/mol
Appearance	black solid
Density	6.11 g/cm3
Melting point	895 °C, 1168 K, 1643 °F
Boiling point	900 °C, 1173 K, 1652 °F (decomp.)
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
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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.

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.

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. Above 900 °C, CoO is stable. 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.