Pentacarbon dioxide
Pentacarbon dioxide, officially penta-1,2,3,4-tetraene-1,5-dione, is an oxide of carbon with formula C5O2 or O=C=C=C=C=C=O.
The compound was described in 1988 by Günter Maier and others, who obtained it by pyrolysis of cyclohexane-1,3,5-trione. It has also been obtained by flash vapor pyrolysis of 2,4,6-triscyclohexane-1,3,5-trione. It is stable at room temperature in solution. The pure compound is stable up to −96 °C, at which point it polymerizes.
