Carbon suboxide

Carbon suboxide
IUPAC name
504-64-3 YesY
3D model (Jmol) Interactive image
ChEBI CHEBI:30086 YesY
ChemSpider 120106 YesY
MeSH Carbon+suboxide
PubChem 136332
Molar mass 68.03 g·mol−1
Appearance colorless gas
Odor strong, pungent odor
Density 0.906 ± 0.06 g cm−3, gas at 298 K
Melting point −111.3 °C (−168.3 °F; 161.8 K)
Boiling point 6.8 °C (44.2 °F; 279.9 K)
Solubility soluble in 1,4-dioxane, ether, xylene, CS2, tetrahydrofuran
1.4538 (6 °C)
0 D
66.99 J/mol K
276.1 J/mol K
-93.6 kJ/mol
Related compounds
Related oxides
carbon dioxide
carbon monoxide
dicarbon monoxide
Related compounds
carbon subsulfide
carbon subnitride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY verify (what is YesYN ?)
Infobox references

Carbon suboxide, or tricarbon dioxide, is an oxide of carbon with chemical formula C3O2 or O=C=C=C=O. Its four cumulative double bonds make it a cumulene. It is one of the stable members of the series of linear oxocarbons O=Cn=O, which also includes carbon dioxide (CO2) and pentacarbon dioxide (C5O2).

The substance was discovered in 1873 by Benjamin Brodie by subjecting carbon monoxide to an electric current. He claimed that the product was part of a series of "oxycarbons" with formulas Cx+1Ox, namely C, C2O, C3O2, C4O3, C5O4, ..., and to have identified the last two;[1][2] however only C3O2 is known. In 1891 Marcellin Berthelot observed that heating pure carbon monoxide at about 550 °C created small amounts of carbon dioxide but no trace of carbon, and assumed that a carbon-rich oxide was created instead, which he named "sub-oxide". He assumed it was the same product obtained by electric discharge and proposed the formula C2O.[3] Otto Diels later stated that the more organic names dicarbonyl methane and dioxallene were also correct.

It is commonly described as an oily liquid or gas at room temperature with an extremely noxious odor.[4]


It is synthesized by warming a dry mixture of phosphorus pentoxide (P4O10) and malonic acid or the esters of malonic acid.[5] Therefore, it can be also considered as the anhydride of malonic anhydride, i.e. the "second anhydride" of malonic acid.[6]

Several other ways for synthesis and reactions of carbon suboxide can be found in a review from 1930 by Reyerson.[7]

Carbon suboxide polymerizes spontaneously to a red, yellow, or black solid. The structure is postulated to be poly(α-pyronic), similar to the structure in 2-pyrone (α-pyrone).[8][9] In 1969, it was hypothesized that the color of the Martian surface was caused by this compound; this was disproved by the Viking Mars probes (the red color is instead due to iron oxide).[10]


Carbon suboxide is used in the preparation of malonates; and as an auxiliary to improve the dye affinity of furs.

Biological role

Those are 6- or 8-ring macrocyclic polymers of carbon suboxide that were found in living organisms. They are acting as an endogenous digoxin-like Na+/K+-ATP-ase and Ca-dependent ATP-ase inhibitors, endogenous natriuretics, antioxidants and antihypertensives

Carbon suboxide, C3O2, can be produced in small amounts in any biochemical process that normally produces carbon monoxide, CO, for example, during heme oxidation by heme oxygenase-1. It can also be formed from malonic acid. It has been shown that carbon suboxide in an organism can quickly polymerize into macrocyclic polycarbon structures with the common formula (C3O2)n (mostly (C3O2)6 and (C3O2)8), and that those macrocyclic compounds are potent inhibitors of Na+/K+-ATP-ase and Ca-dependent ATP-ase, and have digoxin-like physiological properties and natriuretic and antihypertensive actions. Those macrocyclic carbon suboxide polymer compounds are thought to be endogenous digoxin-like regulators of Na+/K+-ATP-ases and Ca-dependent ATP-ases, and endogenous natriuretics and antihypertensives.[11][12][13] Other than that, some authors think also that those macrocyclic compounds of carbon suboxide can possibly diminish free radical formation and oxidative stress and play a role in endogenous anticancer protective mechanisms, for example in the retina.[14]


  1. Brodie, B. C. (1873). "Note on the Synthesis of Marsh-Gas and Formic Acid, and on the Electric Decomposition of Carbonic Oxide" (pdf). Proceedings of the Royal Society. 21 (139–147): 245–247. doi:10.1098/rspl.1872.0052. JSTOR 113037. When pure and dry carbonic oxide [=carbon monoxide] is circulated through the induction-tube, and there submitted to the action of electricity, a decomposition of the gas occurs [...] Carbonic acid [=carbon dioxide] is formed, and simultaneously with its formation a solid deposit may be observed in the induction-tube. This deposit appears as a transparent film of a red-brown color, lining the walls of the tube. It is perfectly soluble in water, which is strongly colored by it. The solution has an intensely acid reaction. The solid deposit, in the dry condition before it has been in contact with the water, is an oxide of carbon.
  2. Brodie, B. C. (1873). "Ueber eine Synthese von Sumpfgas und Ameisensäure und die electrische Zersetzung des Kohlenoxyds". Annalen der Chemie. 169 (1–2): 270–271. doi:10.1002/jlac.18731690119.
  3. Berthelot, M. (1891). "Action de la chaleur sur l'oxyde de carbone". Annales de Chimie et de Physique. 6 (24): 126–132.
  4. Reyerson, L. H.; Kobe, K. (1930). "Carbon Suboxide". Chemical Reviews. 7 (4): 479–492. doi:10.1021/cr60028a002.
  5. Diels, O.; Wolf, B. (1906). "Ueber das Kohlensuboxyd. I". Chemische Berichte. 39: 689–697. doi:10.1002/cber.190603901103.
  6. Perks, H. M.; Liebman, J. F. (2000). "Paradigms and Paradoxes: Aspects of the Energetics of Carboxylic Acids and Their Anhydrides". Structural Chemistry. 11 (4): 265–269. doi:10.1023/A:1009270411806.
  7. Reyerson, L. H.; Kobe, K. (1930). "Carbon Suboxide". Chemical Reviews. 7 (4): 479–492. doi:10.1021/cr60028a002.
  8. Ballauff, M.; Li, L.; Rosenfeldt, S.; Dingenouts, N.; Beck, J.; Krieger-Beck, P. (2004). "Analysis of Poly(carbon suboxide) by Small-Angle X-ray Scattering". Angewandte Chemie International Edition. 43 (43): 5843–5846. doi:10.1002/anie.200460263. PMID 15523711.
  9. Ellern, A.; Drews, T.; Seppelt, K. (2001). "The Structure of Carbon Suboxide, C3O2, in the Solid State". Zeitschrift für anorganische und allgemeine Chemie. 627 (1): 73–76. doi:10.1002/1521-3749(200101)627:1<73::AID-ZAAC73>3.0.CO;2-A.
  10. Plummer, W. T.; Carsont, R. K. (1969). "Mars: Is the Surface Colored by Carbon Suboxide?". Science. 166 (3909): 1141–1142. doi:10.1126/science.166.3909.1141. PMID 17775571.
  11. Franz Kerek (Sep 2000). "The structure of the digitalislike and natriuretic factors identified as macrocyclic derivatives of the inorganic carbon suboxide.". Hypertension Research. 23 (Suppl S33): S33–38. doi:10.1291/hypres.23.Supplement_S33. PMID 11016817.
  12. Robert Stimac, Franz Kerek, Hans-Jurgen Apell (Apr 2003). "Macrocyclic carbon suboxide oligomers as potent inhibitors of the Na,K-ATPase.". Annals of the New York Academy of Sciences. 986: 327–329. doi:10.1111/j.1749-6632.2003.tb07204.x. PMID 12763840.
  13. Franz Kerek, Robert Stimac, Hans-Jürgen Apell, Frank Freudenmann, Luis Moroder (23 December 2002). "Characterization of the macrocyclic carbon suboxide factors as potent Na,K-ATPase and SR Ca-ATPase inhibitors.". Biochimica et Biophysica Acta (BBA) - Biomembranes. 1567 (1-2): 213–220. doi:10.1016/S0005-2736(02)00609-0. PMID 12488055.
  14. Tubaro E. (Jun 1966). "Carbon suboxide, the probable precursor of an antitumor cellular sustance: retina". Boll Chim Farm (in Italian). 105 (6): 415–416. PMID 6005012.
This article is issued from Wikipedia - version of the 11/10/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.