| Propadiene | |
|---|---|
|
Allene |
|
| Identifiers | |
| CAS number | 463-49-0 |
| PubChem | 10037 |
| ChemSpider | 9642 |
| EC number | 207-335-3 |
| UN number | 2200 |
| MeSH | Propadiene |
| ChEBI | CHEBI:37601 |
| ChEMBL | CHEMBL116960 |
| Beilstein Reference | 1730774 |
| Gmelin Reference | 860 |
| Jmol-3D images | Image 1 Image 2 |
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|
|
|
| Properties | |
| Molecular formula | C3H4 |
| Molar mass | 40.06 g mol−1 |
| Exact mass | 40.031300128 g mol-1 |
| Appearance | Colorless gas |
| Melting point |
-136 °C, 137 K, -213 °F |
| Boiling point |
-34 °C, 239 K, -29 °F |
| log P | 1.45 |
| Hazards | |
| MSDS | External MSDS |
| EU classification | F+ |
| R-phrases | R12 |
| S-phrases | S9, S16, S33 |
| NFPA 704 |
4
0
3
|
| Explosive limits | 13% |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
|
| Infobox references | |
Propadiene is the organic compound with the formula H2C=C=CH2. It is the simplest allene, a compound with conjoined C=C double bonds. Propadiene's common name is allene.[1] As a constituent of MAPP gas, it is used as a fuel for specialized welding.
Allene exists in equilibrium with propyne, the mixture sometimes being called MAPD for methyl acetylene (alternative name of propyne)-propadiene:
Keq = 0.22 (270 °C), 0.1 K (5 °C) MAPD is produced as a side product, often an undesirable one, of cracking propane to produce propene, an important feedstock in the chemical industry. MAPD interferes with the catalytic polymerization of propene.[2]