Diiodine oxideDiiodine oxide, also known as iodo hypoiodite, is an oxide of iodine that is equivalent to an acid anhydride of hypoiodous acid. This substance is unstable and it is very difficult to isolate.PreparationDiiodine oxide can be prepared by reacting iodine with potassium iodate in 96% sulfuric acid and then extracting it into chlorinated solvents.ReactionsDiiodine oxide reacts with water to form hypoiodous acid: