1,3,5-Trioxanetrione
The chemical compound 1,3,5-trioxanetrione, or 1,3,5-trioxacyclohexane-2,4,6-trione is an unstable oxide of carbon with formula C3O6. It can be considered a cyclic trimer of carbon dioxide (CO2) or as a triple ketone of 1,3,5-trioxane (1,3,5-trioxacyclohexane).