Carbon suboxide
- Carbon suboxide
- Malonic
- Propadiendion
- Trikohlenstoffdioxid
Colorless gas
Gaseous
3.0 kg · m-3
-107 ° C
6.8 ° C
1.4538 ( 0 ° C)
Attention
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Carbon suboxide, also known as carbon suboxide or malonic, besides carbon monoxide and carbon dioxide, another carbon oxide, which is a compound that is composed exclusively of carbon and oxygen. It is gaseous and stable at room temperature. The toxic and foul-smelling substance can be expected in a group of ketenes, but has, in contrast to most other representatives of this group over two carbonyl groups (C = O).
History
Benjamin Collins Brodie Junior discovered the compound in 1873 under the action of electric current to carbon monoxide. The name goes back to Marcelin Berthelot carbon suboxide.
Representation
In addition to the presentation by dehydration of malonic acid with phosphorus pentoxide:
Can be carbon suboxide thermal decomposition of diacetyl tartaric anhydride, win pyrolysis of Oxalessigsäurediethylether or dehalogenation of Dibrommalonylchlorid.
Properties
Physical Properties
The compound is a linear construction. The bond lengths lie between the values that you would expect for double and triple bonds: 128 pm for the two C -C bonds and 116 pm for the two C -O bonds.
Chemical Properties
Carefully cleaned, carbon suboxide is relatively stable, but very responsive. It reacts when introduced into water to malonic acid.
In the presence of proton-donating substances by radiolysis or photolysis of carbon suboxide polymerizes to form macromolecules. (Referred to in the literature " Red Carbon " and " Red Coal " ) The red to black solid polymerization product has a ribbon-like structure ( see Related links ) and is made up of about 40 C3O2 units with Polypyron -like structure. Also, copolymerization with polyethylene crosslinked copolymers is possible to.
With nucleophiles such as amines, alcohols, phenols or thiols to react carbon suboxide malonamides, esters or thioesters. With hydrazines can be prepared via ring -closing reactions Pyrazolidinderivate. Accordingly, different heterocycles can be synthesized. For example, rule thioamides to Thiazinon derivatives and enamines to the corresponding pyridones. About a photochemical reaction can be produced from ethylene Allen.