Pentacarbon dioxide explained

Pentacarbon dioxide, officially penta-1,2,3,4-tetraene-1,5-dione, is an oxide of carbon (an oxocarbon) 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 2,4,6-tris(diazo)cyclohexane-1,3,5-trione (C₆N₆O₃).^{[1] [2]} Diazo transfer can produce the latter compound from phloroglucinol.^[1] It is stable at room temperature in solution.^[1] The pure compound is stable up to −90 °C, at which point it polymerizes.^[2]

See also

• Ethylene dione (C₂O₂)
• Carbon suboxide (C₃O₂)

Notes and References

1. C₅O₂ (1,2,3,4-Pentatetraene-1,5-dione), a New Oxide of Carbon . Maier, G. . Reisenauer, H. P. . Schäfer, U. . Balli, H. . Angewandte Chemie International Edition . 1988 . 27 . 4 . 566–568 . 10.1002/anie.198805661.
2. Book: Eastwood, F. W. . 1997 . Gas Phase Pyrolytic Methods for the Preparation of Carbon-Hydrogen and Carbon-Hydrogen-Oxygen Compounds . Vallée, Y. . Gas Phase Reactions in Organic Synthesis . CRC Press . 90-5699-081-0.