Norbornene

Structural formula
General
Surname	Norbornene
other names	Bicyclo [2.2.1] hept-2-en 8,9,10-trinor-2-bornene
Molecular formula	C 7 H 10
Brief description	white solid with a sour odor
External identifiers / databases
CAS number 498-66-8 EC number 207-866-0 ECHA InfoCard 100.007.152 PubChem 10352 Wikidata Q420176
properties
Molar mass	94.15 g mol −1
Physical state	firmly
density	0.87 g cm −3 (20 ° C)
Melting point	44-47 ° C
boiling point	95-96 ° C
Vapor pressure	32 h Pa (65 ° C)
solubility	very heavy in water (0.13 g l −1 at 20 ° C)
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 228-319-411 P: 210-273-305 + 351 + 338
Toxicological data	11300 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Norbornene , also norbornylene or norcamphen , are common names for a bridged, bicyclic hydrocarbon. At room temperature, norbornene is a white, pungent-smelling solid. The molecule consists of a cyclohexene ring, which is 1,4-bridged with a methylene group . The double bond leads to ring tension and is partly responsible for the increased reactivity of the molecule.

Norbornene reacts with water in an acid-catalyzed reaction to form norborneol . This reaction is of interest to chemists working with nonclassical ions .

Manufacturing

Like many of its derivatives, norbornene is produced by the Diels-Alder reaction of cyclopentadiene with ethene .

Related bicyclic compounds are norbornadiene , which has the same carbon structure but a further double bond, and norbornane , also with the same structure but without double bonds and therefore saturated.

Polynorbornene

Norbornenes are important monomers for ROMP reactions ( ring-opening metathesis polymerization , i.e. ring-opening metathesis polymerization ; see also metathesis ), which polymerize under the action of Grubbs catalysts (mostly carbene complexes of ruthenium ). However, other polymerization reactions are possible with other conditions.

Polynorbornenes are polymers that are characterized by high glass transition temperatures and high optical clarity.

In addition to ROMP reactions, norbornene monomers can also polymerize through vinyl addition polymerizations.

Ethylidene norbornene is a related monomer that is derived from cyclopentadiene and butadiene .

Applications

Norbornene is used as a raw material for pharmaceutical intermediates, pesticides , artificial fragrances and general organic synthesis. In combination with ethene , norbornene can be converted into a cyclo-olefin copolymer .

literature

• IUPAC - Nomenclature of Organic Chemistry, Sections AH, Pergamon Press, 1979, pp. 49, 498

Web links

Commons : Norbornen  - collection of images, videos and audio files

• IUPAC online, Rule A-31

Individual evidence

1. ↑ ^{a b c d e} Norbornene data sheet (PDF) from Merck , accessed on April 16, 2011.
2. ↑ ^{a b c d} Entry on 2-norbornene in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
3. ↑ F. Scholz, D. Himmel, FW Heinemann, P. v. R. Schleyer, K. Meyer, I. Krossing: Crystal Structure Determination of the Nonclassical 2-Norbornyl Cation. In: Science. 341, 2013, pp. 62–64, doi : 10.1126 / science.1238849 .
4. ^ Paul Binger, Petra Wedemann, Udo H. Brinker: Cyclopropene: A New Simple Synthesis And Its Diels-Alder Reaction With Cyclopentadiene In: Organic Syntheses . 77, 2000, p. 254, doi : 10.15227 / orgsyn.077.0254 ; Coll. Vol. 10, 2004, p. 231 ( PDF ).
5. ↑ Masaji Oda, Takeshi Kawase, Tomoaki Okada, Tetsuya Enomoto: 2-Cyclohexene-1,4-Dione In: Organic Syntheses . 73, 1996, p. 253, doi : 10.15227 / orgsyn.073.0253 ; Coll. Vol. 9, 1998, p. 186 ( PDF ).