The iodite ion, or iodine dioxide anion, is the halite with the chemical formula IO−2. Within the ion, the iodine exists in the oxidation state of +3.
Iodite anion
Iodites (including iodous acid) are highly unstable and have been observed1 but never isolated. They will rapidly disproportionate to molecular iodine and iodates.2 However, they have been detected as intermediates in the conversion between iodide and iodate.34
Other oxyanions
Iodine can assume oxidation states of −1, +1, +3, +5, or +7. A number of neutral iodine oxides are also known.
| Iodine oxidation state | −1 | +1 | +3 | +5 | +7 |
|---|---|---|---|---|---|
| Name | iodide | hypoiodite | iodite | iodate | periodate |
| Formula | I− | IO− | IO−2 | IO−3 | IO−4 or IO5−6 |
References
Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8. 978-0-08-037941-8 ↩
Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8. 978-0-08-037941-8 ↩
Gupta, Yugul Kishore; Sharma, Devendra Nath (August 1971). "Kinetics and mechanism of the reduction of iodate to iodite by bromide in the presence of phenol". The Journal of Physical Chemistry. 75 (16): 2516–2522. doi:10.1021/j100685a018. /wiki/Doi_(identifier) ↩
Gilles, Mary K.; Polak, Mark L.; Lineberger, W. C. (1992). "Photoelectron spectroscopy of the halogen oxide anions FO−, ClO−, BrO−, IO−, OClO−, and OIO−". The Journal of Chemical Physics. 96 (11): 8012. Bibcode:1992JChPh..96.8012G. doi:10.1063/1.462352. /wiki/W._Carl_Lineberger ↩