Acyclic diene metathesis or ADMET (distinguish from

ADME ADME is an abbreviation in pharmacokinetics and pharmacology for " absorption, distribution, metabolism, and excretion", and describes the disposition of a pharmaceutical compound within an organism. The four criteria all influence the drug le ...

) is a special type of

olefin metathesis Olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the scission and regeneration of carbon-carbon double bonds. Because of the relative simplicity of olefin metathesis, it often create ...

used to

polymerize In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many for ...

terminal

diene In organic chemistry a diene ( ) (diolefin ( ) or alkadiene) is a covalent compound that contains two double bonds, usually among carbon atoms. They thus contain two alk''ene'' units, with the standard prefix ''di'' of systematic nomenclature. ...

s to

polyene In organic chemistry, polyenes are poly- unsaturated, organic compounds that contain at least three alternating double () and single () carbon–carbon bonds. These carbon–carbon double bonds interact in a process known as conjugation, resultin ...

The new double bonds formed can be in cis- or trans-configurations. The exact ratio depends on the identities of the monomer and catalyst. ADMET is a type of step-growth,

condensation polymer In polymer chemistry, condensation polymers are any kind of polymers whose process of polymerization involves a condensation reaction (i.e. a small molecule, such as water or methanol, is produced as a byproduct). Condensation polymers are form ...

ization. It should be distinguished from

ring-opening metathesis polymerization Ring-opening metathesis polymerization (ROMP) is a type of olefin metathesis chain-growth polymerization. The driving force of the reaction is relief of ring strain in cyclic olefins (e.g. norbornene or cyclopentene). A variety of heterogeneous ...

(ROMP), which is a chain-growth,

addition polymer In polymer chemistry, an addition polymer is a polymer that forms by simple linking of monomers ''without'' the co-generation of other products. Addition polymerization differs from condensation polymerization, which ''does'' co-generate a product ...

ization. Whereas ADMET is driven by the release of volatile ethylene gas, ROMP is driven by the relief of ring-strain. While the concept of ADMET had been discussed in the scientific literature since the 1970s, the first successful ADMET polymerization was reported in 1991. In this report, 1,5-hexadiene and 1,9-decadiene were polymerized to 1,4-

polybutadiene Polybutadiene utadiene rubber BRis a synthetic rubber. Polybutadiene rubber is a polymer formed from the polymerization of the monomer 1,3-butadiene. Polybutadiene has a high resistance to wear and is used especially in the manufacture of tir ...

and poly(octenylene), respectively. The polybutadiene had a weight average molar mass (M_w) of 28,000 with over 70% trans double bonds. The poly(octenylene) had an M_w of 108,000 with over 90% trans double bonds. ADMET has been applied in the synthesis of a variety of polymers. Because of the higher degree of control in ADMET than in traditional radical polymerizations, it has been used to synthesize model polymers that would otherwise be difficult to prepare. Examples include purely linear

polyethylene Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including bo ...

, alternating and block

copolymer In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are some ...

s of ethylene with various other vinyl monomers, chiral polymers and polymers with embedded amino acids. The high functional group tolerance of ruthenium-catalyzed ADMET has been applied in the synthesis of new

supramolecular Supramolecular chemistry refers to the branch of chemistry concerning chemical systems composed of a discrete number of molecules. The strength of the forces responsible for spatial organization of the system range from weak intermolecular forces, ...

structures.

References

{{DEFAULTSORT:Acyclic Diene Metathesis Polymerization reactions