:Oxalic anhydride

{{Chembox

| verifiedrevid = 447059492

| Name =

| ImageFile = Oxalic-anhydride-2D.png

| ImageClass = skin-invert-image

| ImageFile1 = File:Chemfm oxalic anhydride.svg

| PIN = Oxiranedione

| OtherNames = oxalic anhydride
ethanedioic anhydride

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| Section1 = {{Chembox Identifiers

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

| ChemSpiderID = 13693079

| InChI = 1/C2O3/c3-1-2(4)5-1

| InChIKey = PFPYHYZFFJJQFD-UHFFFAOYAE

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

| StdInChI = 1S/C2O3/c3-1-2(4)5-1

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

| StdInChIKey = PFPYHYZFFJJQFD-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|??}}

| CASNo = 308818-63-5

| PubChem = 23297885

| SMILES = O=C1OC1=O

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| Section2 = {{Chembox Properties

| C=2 | O=3

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Oxalic anhydride or ethanedioic anhydride, also called oxiranedione, is a hypothetical organic compound, one of several isomers having the formula C₂O₃ that have been studied computationally. It can be viewed as the anhydride of oxalic acid or the two-fold ketone of ethylene oxide. It is an oxide of carbon (an oxocarbon).

The simple compound apparently has yet to be observed (as of 2009). In 1998, however, Paolo Strazzolini and others have claimed the synthesis of dioxane tetraketone (C₄O₆), which can be viewed as the cyclic dimer of oxalic anhydride.{{cite journal| title = The reaction between ethanedioyl (oxalyl) dihalides and Ag₂C₂O₄: a route to Staudinger's elusive ethanedioic (oxalic) acid anhydride|author1=Paolo Strazzolini |author2=Alberto Gambi |author3=Angelo G. Giumanini |author4=Hrvoj Vancik | journal = J. Chem. Soc., Perkin Trans. 1| issue = 16| year = 1998| pages = 2553–2558| doi = 10.1039/a803430c}}

It has been conjectured to be a fleeting intermediate in the thermal decomposition of certain oxalates{{cite journal |author1=Ahmed A. El-Sherif |author2=Bakir J. A. Jeragh |year=2007 |title=Mixed ligand complexes of Cu(II)-2-(2-pyridyl)-benzimidazole and aliphatic or aromatic dicarboxylic acids: Synthesis, characterization and biological activity |journal=Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy |volume=68 |issue=1 |pages=877–882 |doi=10.1016/j.saa.2006.12.073|pmid=17320475 |bibcode=2007AcSpA..68..877E }} and certain chemoluminescent reactions of oxalyl chloride.{{cite tech report |author1=M. M. Rauhut |author2=L. J. Bollyky |author3=R. A. Clarke |author4=M. Loy |author5=B. G.Roberts |date=September 30, 1965 |title= Chemiluminescent Materials (AD0621845) |number=9 |institution=Office of Naval Research and Advanced Research Projects Agency |url=https://apps.dtic.mil/sti/pdfs/AD0621845.pdf |archive-url=https://web.archive.org/web/20210722233835/https://apps.dtic.mil/sti/pdfs/AD0621845.pdf |url-status=live |archive-date=July 22, 2021 }}