This is valence isoelectronic with the ozonide ion. Dichloromethane is often used as a 1&colon;1 cosolvent to facilitate timely cleavage of the ozonide. Sometimes called thiozonide, by analogy with the ozonide anion, . After a sequence of cleavage and rearrangement, an organic ozonide is formed. "Trioxidanediyl" (or "ozonide") is used, non-systematically, to refer to the substituent group (-OOO-).