ketene

Ethenone is the formal name for ketene, an organic compound with formula or . It is the simplest member of the ketene class. It is an important reagent for acetylations.

== Properties == Ethenone is a highly reactive gas (at standard conditions) and has a sharp, irritating odour. It is reasonably stable only at low temperatures (−80 °C). It must therefore always be prepared for each use and processed immediately, otherwise a dimerization to diketene occurs, or polymers are formed that are difficult to handle. Its polymerization can be reduced by adding sulfur dioxide. Because of its cumulative double bonds, it adds readily to H-acidic compounds, reacting with water, for example, to form acetic acid, and with primary or secondary amines to yield the corresponding acetamides.