Tetracarbon dioxide is an oxide of carbon, a chemical compound of carbon and oxygen, with chemical formula C4O2 or O=C=C=C=C=O. It can be regarded as butatriene dione, the double ketone of butatriene — more precisely 1,2,3-butatriene-1,4-dione. Butatriene dione is the fourth member of the family of linear carbon dioxides O(=C)n=O, that includes ...