Dichlorine trioxide

{{Chembox

| Verifiedfields = changed

| verifiedrevid = 476997879

| ImageFileL1 = Dichlortrioxid.svg

| ImageFileR1 = Dichlorine-trioxide-3D-spacefill.png

| IUPACName = dichlorine trioxide

| OtherNames = chlorine trioxide
chlorine chlorate
chlorine(I,V) oxide

| Reference =

{{cite book | last = Lide | first = David R. | year = 1998

| title = Handbook of Chemistry and Physics

| edition = 87 | volume =

| location = Boca Raton, Florida

| publisher = CRC Press

| isbn = 0-8493-0594-2 | pages = 4–51}}

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 11514723

| InChI = 1/Cl2O3/c1-5-2(3)4

| InChIKey = SAUMVKNLVQDHMJ-UHFFFAOYAS

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/Cl2O3/c1-5-2(3)4

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = SAUMVKNLVQDHMJ-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|changed|??}}

| CASNo = 17496-59-2

| PubChem = 167661

| SMILES = ClOCl(=O)=O

}}

|Section2={{Chembox Properties

| Formula = Cl₂O₃

| MolarMass = 118.903 g/mol

| Appearance = dark brown solid

| Density =

| MeltingPt = explodes below 0 °C

| BoilingPt =

| Solubility = }}

|Section3={{Chembox Hazards

| MainHazards =

| FlashPt =

| AutoignitionPt = }}

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Dichlorine trioxide, Cl₂O₃, is a chlorine oxide. It is a dark brown solid discovered in 1967 which is explosive even below 0 °C.{{cite book |author= N. N. Greenwood and A. Earnshaw |title=Chemistry of the Elements |year=1997 |publisher=Butterworth-Heinemann |isbn=978-0750633659 }} It is formed by the low-temperature photolysis of ClO₂ and is formed along with Cl₂O₆, Cl₂ and O₂. Its structure is believed to be OCl−ClO₂ with possible isomers such as Cl−O−ClO₂.Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier {{ISBN|0-12-352651-5}} The isomer having a structure of OCl–O–ClO would be the theoretical anhydride of chlorous acid.