tricarbon dioxide Chemical Properties

Melting point:

-111.3°

Boiling point:

bp760 6.8°

Density 

d40 1.114

refractive index 

n0D 1.45384; nD-12 1.46757

solubility 

reacts with H2O

form 

colorless gas

color 

colorless

Water Solubility 

forms malonic acid with H2O [MER06]

tricarbon dioxide Usage And Synthesis

Chemical Properties

colorless, highly refractive liquid or colorless gas, which burns with a blue sooty flame; odor like acrolein or mustard oil; structure: O=C=C=C=O [MER06]

Physical properties

Colorless gas; strong, pungent odor; gas density 2.985 g/L; liquid density 1.114 g/mL at 0°C; refractive index 1.4538 (at 0°C); vapor pressure 588 torr at 0°C; liquefies at 6.8°C; freezes at -111.3°C; burns with a blue sooty flame; reacts with water. The compound is unstable, polymerizing on storage.

Uses

preparation of malonates; improving dye affinity of fibers.

Definition

ChEBI: Carbon suboxide is a carbon oxide and a member of allenes.

Preparation

Carbon suboxide is prepared by dehydration of malonic acid with phosphorus pentoxide in vacuum at 140 to 150°C:
CH₂(COOH)₂→ C₃O₂ + 2H₂O
Alternatively, the compound may be prepared by thermal dissociation of diacetyltartaric anhydride.

Hazard

Carbon suboxide forms explosive mixtures in air. The lower and upper explosive limits are 6 to 30% by volume in air, respectively. The gas is a strong lacrimator and an irritant to eyes, nose and respiratory tract. Exposure to high concentations is dangerous. .