Iodite

{{Chembox

| ImageFile = Iodite ion.svg

| ImageSize = 150px

| IUPACName = iodite

| SystematicName = dioxidoiodate(1−)

| Section1 = {{Chembox Identifiers

| CASNo = 20499-55-2

| PubChem = 5460637

| ChemSpiderID = 4574132

| SMILES = [O-][I+][O-]

| InChI = 1S/HIO2/c2-1-3/h(H,2,3)/p-1

}}

| Section2 = {{Chembox Properties

| Formula = {{chem|IO|2|−}}

| MolarMass = 58.90 g/mol

| Appearance =

| Density =

| MeltingPt =

| BoilingPt =

| Solubility =

| ConjugateAcid = Iodous acid

}}

| Section3 = {{Chembox Related

| OtherAnions = Chlorite
Bromite

}}

The iodite ion, or iodine dioxide anion, is the halite with the chemical formula {{chem|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 observed{{Greenwood&Earnshaw}} but never isolated.{{cn|date=September 2023}} They will rapidly disproportionate to molecular iodine and iodates.{{Greenwood&Earnshaw}} However, they have been detected as intermediates in the conversion between iodide and iodate.{{cite journal|last1=Gupta|first1=Yugul Kishore|last2=Sharma|first2=Devendra Nath|title=Kinetics and mechanism of the reduction of iodate to iodite by bromide in the presence of phenol|journal=The Journal of Physical Chemistry|date=August 1971|volume=75|issue=16|pages=2516–2522|doi=10.1021/j100685a018}}{{cite journal|last1=Gilles|first1=Mary K.|last2=Polak|first2=Mark L.|last3=Lineberger|authorlink3=W. Carl Lineberger|first3=W. C.|title=Photoelectron spectroscopy of the halogen oxide anions FO−, ClO−, BrO−, IO−, OClO−, and OIO−|journal=The Journal of Chemical Physics|date=1992|volume=96|issue=11|pages=8012|doi=10.1063/1.462352|bibcode=1992JChPh..96.8012G}}

Other oxyanions

Iodine can assume oxidation states of −1, +1, +3, +5, or +7. A number of neutral iodine oxides are also known.

class="wikitable"
Iodine oxidation state \| −1 \| +1 \| +3 \| +5 \| +7
Name \| iodide \| hypoiodite \| iodite \| iodate \| periodate
Formula \| I⁻ \| IO⁻ \| {{chem\|IO\|2\|−}} \| {{chem\|IO\|3\|−}} \| {{chem\|IO\|4\|−}} or {{chem\|IO\|6\|5−}}

class="wikitable"

Iodine oxidation state

| −1

| +1

| +3

| +5

| +7

Name

| iodide

| hypoiodite

| iodite

| iodate