Ethylidene norbornene
Chemical compound
From Wikipedia, the free encyclopedia
Ethylidene norbornene (ENB) is an organic compound that consists of an ethylidene (CH3C(H)=) group attached to norbornene. It is a colorless liquid. The molecule consists of two sites of unsaturation. The compound consists of (E)- and (Z)-stereoisomers, but the mixtures are typically not separated.
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| Names | |
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| Other names
2-ethylidene-5-norbornene | |
| Identifiers | |
3D model (JSmol) |
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| ChEMBL | |
| ChemSpider | |
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PubChem CID |
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| UNII | |
| UN number | 1993 1992 |
CompTox Dashboard (EPA) |
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| Properties | |
| C9H12 | |
| Molar mass | 120.195 g·mol−1 |
| Appearance | colorless liquid |
| Density | 0.893 g/mL |
| Melting point | −80 °C (−112 °F; 193 K) |
| Boiling point | 146 °C (295 °F; 419 K) |
| Hazards | |
| GHS labelling: | |
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| Danger | |
| H226, H304, H315, H317, H319, H332, H335, H373, H411 | |
| P210, P233, P240, P241, P242, P243, P260, P264, P264+P265, P271, P272, P273, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P317, P319, P321, P331, P333+P317, P337+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation and use
It is prepared by isomerization of vinyl norbornene, which in turn is obtained by the Diels-Alder reaction of butadiene and cyclopentadiene.[1]
Ethylidene norbornene can be produced in two steps from cyclopentadiene.
It is a monomer that used in the production of the commercial polymer EPDM. Only the ring alkene participates in the copolymerization. The exocyclic double bond (the ethylidene group) undergoes sulfur vulcanization.