Iridium(IV) oxide

Summary

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]

Iridium(IV) oxide
Names
Other names
Iridium dioxide
Identifiers
  • 12030-49-8 checkY
3D model (JSmol)
  • Interactive image
ChemSpider
  • 10605808 checkY
ECHA InfoCard 100.031.572 Edit this at Wikidata
  • 82821
UNII
  • CL6CQW9MWS checkY
  • DTXSID1051222 Edit this at Wikidata
  • InChI=1S/Ir.2O/q+4;2*-2 checkY
    Key: NSTASKGZCMXIET-UHFFFAOYSA-N checkY
  • InChI=1/Ir.2O/q+4;2*-2
    Key: NSTASKGZCMXIET-UHFFFAOYAQ
  • [Ir+4].[O-2].[O-2]
Properties
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
insoluble
+224.0·10−6 cm3/mol
Structure
Rutile (tetragonal)
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).
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Infobox references

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]

Application edit

Iridium dioxide can be used as an anode electrode for industrial electrolysis and as a microelectrode for electrophysiological studies.[4]

Iridium dioxide can be used to make coated electrodes.[5]

References edit

  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.
  4. ^ 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. ISSN 1523-9829. PMID 18429704.
  5. ^ "改性二氧化铱电极研制--《无机盐工业》1998年03期". www.cnki.com.cn. Retrieved 2021-05-21.