Norbornene or norbornylene or norcamphene is a bridged cyclic hydrocarbon

Hydrocarbon

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

. It is a white solid with a pungent sour odor. The molecule

Molecule

A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

 consists of a cyclohexene

Cyclohexene

Cyclohexene is a hydrocarbon with the formula C6H10. This cycloalkene is a colorless liquid with a sharp smell. It is an intermediate in various industrial processes...

 ring bridged with a methylene

Methylene

Methylene is a chemical species in which a carbon atom is bonded to two hydrogen atoms. Three different possibilities present themselves:* the -CH2- substituent group: e.g., dichloromethane ....

 group in the para position

Arene substitution patterns

Arene substitution patterns are part of organic chemistry IUPAC nomenclature and pinpoint the position of substituents other than hydrogen in relation to each other on an aromatic hydrocarbon.- Ortho, meta, and para substitution :...

. The molecule carries a double bond

Double bond

A double bond in chemistry is a chemical bond between two chemical elements involving four bonding electrons instead of the usual two. The most common double bond, that between two carbon atoms, can be found in alkenes. Many types of double bonds between two different elements exist, for example in...

 which induces significant ring strain

Ring strain

In organic chemistry, ring strain is the tendency of a cyclic molecule, such as cyclopropane, to destabilize when its atoms are in non-favorable high energy spatial orientations...

 and significant reactivity.

Norbornene, like many of its derivatives, is made by a Diels-Alder reaction

Diels-Alder reaction

The Diels–Alder reaction is an organic chemical reaction between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene system. The reaction can proceed even if some of the atoms in the newly formed ring are not carbon...

 of cyclopentadiene

Cyclopentadiene

Cyclopentadiene is an organic compound with the formula C5H6. This colorless liquid has a strong and unpleasant odor. At room temperature, this cyclic diene dimerizes over the course of hours to give dicyclopentadiene via a Diels–Alder reaction...

 and ethylene

Ethylene

Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...

. Related bicyclics are norbornadiene

Norbornadiene

Norbornadiene is an organic compound. This bicyclic hydrocarbon is the most stable diolefin derived from the norbornane and norbornene. Norbornadiene is primarily of interest as a ligand in homogeneous catalysis, but it has been heavily studied due to its high reactivity and distinctive...

 which has the same carbon skeleton but with two double bonds and norbornane

Norbornane

Norbornane is an organic compound and a saturated hydrocarbon with chemical formula C7H12. It is a crystalline compound with melting point 88 °C. The carbon skeleton is a cyclohexane ring bridged by a methylene group in the 1,4- position, and is a bridged bicyclic compound...

 which is completely saturated without double bonds.

Norbornene undergoes an acid-catalyzed hydration reaction

Hydration reaction

In organic chemistry, a hydration reaction is a chemical reaction in which a hydroxyl group and a hydrogen cation are added to the two carbon atoms bonded together in the carbon-carbon double bond which makes up an alkene functional group. The reaction usually runs in a strong acidic, aqueous...

 with water to form norborneol

Endo-Norborneol

endo-Norborneol is an alcohol.-External links:* * Reaction of organic compounds under high temperature – dilute acid conditions. III. The perdeuteration of bicyclo[2.2.1]heptanes...

. This reaction is of great interest to chemists studying non-classical ion

Non-classical ion

Non-classical ions in organic chemistry are a special type of carbonium ions displaying delocalization of sigma bonds in 3-center-2-electron bonds of bridged systems. The term non-classical ion was first used by John D...

s.

Polynorbornenes

Norbornenes are important monomer

Monomer

A monomer is an atom or a small molecule that may bind chemically to other monomers to form a polymer; the term "monomeric protein" may also be used to describe one of the proteins making up a multiprotein complex...

s in ring-opening metathesis polymerizations (ROMP) with for instance the Grubbs' catalyst

Grubbs' catalyst

Grubbs' Catalyst is a transition metal carbene complex named after Robert H. Grubbs, the chemist who first synthesized it. There are two generations of the catalyst, as shown on the right. In contrast to other olefin metathesis catalysts, Grubbs' Catalysts tolerate other functional groups in the...

. Polynorbornenes are polymer

Polymer

A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...

s with high glass transition temperatures and high optical clarity.
In addition to ROMP polymerization, norbornene monomers also undergo vinyl-addition polymerization.

Ethylidene norbornene is a related monomer derived from cyclopentadiene

Cyclopentadiene

Cyclopentadiene is an organic compound with the formula C5H6. This colorless liquid has a strong and unpleasant odor. At room temperature, this cyclic diene dimerizes over the course of hours to give dicyclopentadiene via a Diels–Alder reaction...

 and butadiene.

Practical uses

Norbornene does not have as many practical uses as ethylene

Ethylene

Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...

 or other commodity chemicals. It is utilized to make pharmaceutical intermediates, pesticide compounds, specialty fragrances and in general organic synthesis. When combined with ethylene, norbornene will react and turn into a cyclic olefin copolymer

Cyclic Olefin Copolymer

Cyclic Olefin Copolymer is an amorphous polymer made by several polymer manufacturers. COC is a relatively new class of polymers when compared to polypropylene and polyethylene...

.

Polynorbornene, known under Norsorex, a brand from Astrotech Advanced Elastomerproducts GmbH since 2008, is used mainly in the rubber industry for anti-vibration (rail, building, industry), anti-impact (personal protective equipment, shoe parts, bumpers) and grip improvement (toy tires, racing tires, transmission systems, transports systems for copiers, feeders, etc.)

• Reachable performances: Loss factors (tan delta) larger than 3, rebounds of less than 1%, tear strengths of 50 N/mm², friction coefficients of 2 and more, Shore hardness between 4 and 90 Shore A.
• Second main application: oil-binding system with absorption capability of hydrocarbons, 10 times of own weight
• Norbornene is commonly used in transition metal catalysis to affect migration of electrophilic transition metals