Iridium(IV) oxide

Iridium(IV) oxide
Names
	Other names Iridium dioxide
Identifiers
CAS Number	12030-49-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	10605808 ;
ECHA InfoCard	100.031.572
PubChem CID	82821;
UNII	CL6CQW9MWS ;
CompTox Dashboard (EPA)	DTXSID1051222 ;
	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	blue-black solid
Density	11.66 g/cm3
Melting point	1,100 °C (2,010 °F; 1,370 K) decomposes
Solubility in water	insoluble
Magnetic susceptibility (χ)	+224.0·10−6 cm3/mol
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
	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

Iridium(IV) oxide, IrO₂, is the only well-characterised oxide of iridium. It is a blue-black solid. The compound adopts the TiO₂ rutile structure, featuring 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]

As described by its discoverers, it can be formed by treating the green form of iridium trichloride with oxygen at high temperatures:

2 IrCl₃ + 2 O₂ → 2 IrO₂ + 3 Cl₂

A hydrated form is also known.^[3]

^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
^ 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. PMID 18429704.
^ H. L. Grube (1963). "The Platinum Metals". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. NY: Academic Press. p. 1590.

[Greenwood-1] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.

[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. PMID 18429704.

[3] H. L. Grube (1963). "The Platinum Metals". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. NY: Academic Press. p. 1590.

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