TetraoxidaneTetraoxidane is an inorganic compound of hydrogen and oxygen with the chemical formula. This is one of the unstable hydrogen polyoxides.SynthesisThe compound is prepared by a chemical reaction between hydroperoxyl radicals at low temperatures:Physical propertiesThis is the fourth member of the polyoxidanes. The first three are water, hydrogen peroxide, and trioxidane. Tetraoxidane is more unstable than the previous compounds. The term "tetraoxidane" extends beyond the parent compound to several daughter compounds of the general formula, where R can be hydrogen, halogen, or various inorganic and organic monovalent radicals. The two Rs together can be replaced by a divalent radical, so heterocyclic tetraoxidanes also exist.IonizationTetraoxidane autoionizes when in liquid form: