| Ethenone | |
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Ethenone |
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Other names
Ketene |
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| Identifiers | |
| CAS number | 463-51-4 |
| ChemSpider | 9643 |
| ChEBI | CHEBI:48003 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C2H2O |
| Molar mass | 42.04 g/mol |
| Appearance | Colourless gas |
| Melting point |
-150.5 °C (-239 °F) |
| Boiling point |
-56.1 °C (-69 °F) |
| Hazards | |
| MSDS | External MSDS |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Ethenone is the formal name for ketene, an organic compound with formula C2H2O or H2C=C=O. It is the simplest member of the ketene class. It is a tautomer of ethynol.
Contents |
Ethenone is a colourless gas at STP and has a sharp irritating odour. Ethenone has molecular weight 42.04, melting point -150.5 °C (-239 °F) and boiling point -56.1 °C (-69 °F). It is soluble in acetone, ethanol, ethyl ether, aromatic solvents and halocarbons.
Ethenone can be prepared in the laboratory by pyrolysis of acetone vapor.[1]
Ethenone is very reactive, tending to react with nucleophiles to form an acetyl group. For example, it reacts with acetic acid to form acetic anhydride.
Ethenone will also react with itself via a [2+2] cycloaddition to form cyclic dimers known as diketenes. For this reason, it should not be stored for long periods.
Exposure to concentrated levels causes humans to experience irritation of body parts such as the eye, nose, throat and lungs. Extended toxicity testing on mice, rats, guinea pigs and rabbits showed that ten minute exposures to concentrations of freshly generated ethenone as low as 0.2 mg/liter (116 ppm) may produce a high percentage of deaths in small animals. These findings put ethenone in the same order of toxicity as phosgene (0.2-20 mg/liter) and hydrogen cyanide (0.2-0.5 mg/liter). Death is from pulmonary edema and is entirely similar to, but much more rapid than is the case with phosgene poisoning.[2]