Carbon suboxide

Carbon suboxide, or tricarbon dioxide, is an oxide of carbon with the chemical formula O=C=C=C=O. Its four cumulative double bonds make it a cumulene.

 Discovery 
Benjamin Brodie discovered carbon suboxide in 1873 by passing electricity through carbon monoxide. He claimed that this substance was only one of many "oxycarbons" (with formulas Cx+1Ox, i.e. C, C 2O, C3O2, C4O3, C< sub>5OR4, ...); he also said he had identified the last two oxycarbons in this series.  However, only C3O2 is known today.

In 1891 Marcellin Berthelot noticed that heating pure carbon monoxide to around 550°C creates small amounts of carbon dioxide but no carbon at all. He assumed that a carbon-rich oxide was created instead. He called this substance "suboxide". He thought that it was the same product obtained by an electric arc and proposed the formula C2O. Otto Diels later claimed that the more organic names dicarbonyl methane and dioxalene were correct as well.

 Characteristics 
Carbon suboxide is commonly described as an oily liquid or gas at room temperature with a very noxious smell.

Carbon suboxide spontaneously polymerizes to a red, yellow, or black solid. The structure is postulated to be poly(α-pyrone), similar to the structure in 2-Pyrone (α-pyrone). In 1969, it was hypothesized that carbon suboxide caused the color of Mars's surface; the Viking probes later disproved this idea.

 Uses 
Carbon suboxide is used to make malonates and to improve the affinity of leather dyes.

 References 

 Other websites 
 WebElements page on compound's properties

Category:Carbon compounds
Category:Oxygen compounds