Iridium(IV) oxide

Iridium(IV) oxide

Names
Other names Iridium dioxide
Identifiers
CAS Number	12030-49-8
3D model (Jmol)	Interactive image
ChemSpider	10605808
ECHA InfoCard	100.031.572
PubChem	82821
InChI InChI=1S/Ir.2O/q+4;2*-2 Key: NSTASKGZCMXIET-UHFFFAOYSA-N InChI=1/Ir.2O/q+4;2*-2 Key: NSTASKGZCMXIET-UHFFFAOYAQ
SMILES [Ir+4].[O-2].[O-2]
Properties
Chemical formula	IrO2
Molar mass	224.22 g/mol
Appearance	black solid
Density	11.66 g/cm^3
Melting point	1,100 °C (2,010 °F; 1,370 K) decomposes
Solubility in water	insoluble
Structure
Crystal structure	Rutile (tetragonal)
Coordination geometry	Octahedral (Ir); Trigonal (O)
Hazards
Flash point	Non-flammable
Related compounds
Other anions	iridium(IV) fluoride, iridium disulfide
Other cations	rhodium dioxide, osmium dioxide, platinum dioxide
Related compounds	iridium(III) oxide
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

Iridium(IV) oxide, IrO₂, is the only well characterised oxide of iridium. Its crystal has the TiO₂, rutile structure containing six coordinate iridium and three coordinate oxygen.^[1]

It is used with other rare oxides in the coating of anode-electrodes for industrial electrolysis and in microelectrodes for electrophysiology research.^[2]

It can be formed by oxidation of iridium black, a finely divided powder of iridium metal.

References

1. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.
2. Cogan, Stuart F. (August 2008). "Neural Stimulation and Recording Electrodes". Annual Review of Biomedical Engineering. 10 (1): 275–309. doi:10.1146/annurev.bioeng.10.061807.160518.