Editing Polyacetylene (section)

{{Short description|Organic polymer made of the repeating unit [C2H2]}}
{{About|polymers with alternating double and single bonds|compounds with multiple triple bonds|polyyne}}
{{Chembox
|Verifiedfields = changed
|verifiedrevid = 464209345
|IUPACName = Polyethyne
|OtherNames = Polyacetylene, PAc
|ImageFile1 = Trans-Polyacetylene.svg
|ImageCaption1 = [[Skeletal formula]] of ''trans''-polyacetylene
|ImageName1 = ''trans''-polyacetylene
|ImageSize1 = 185px
|ImageFile2 = Cis-Polyacetylene.svg
|ImageCaption2 = Skeletal formula of ''cis''-polyacetylene
|ImageName2 = ''cis''-polyacetylene
|ImageSize2 = 180px
|ImageFile3 = Cis-and-trans-polyacetylene-chains-symmetric-8-based-on-xtals-3D-bs-17.png
|ImageCaption3 = [[Ball-and-stick model]]s of the transoidal (top) and cisoidal (bottom) conformations of the ''trans''  isomer<ref>{{cite journal |first1=Giovanni |last1=Perego |first2=Gabriele |last2=Lugli |first3=Ugo |last3=Pedretti |first4=Marco |last4=Cesari |title=X-ray investigation on highly oriented polyacetylene, 1. Crystal structure of cis- and trans-polyacetylene |journal=[[Die Makromolekulare Chemie|Makromol. Chem.]] |year=1988 |volume=189 |issue=11 |pages=2657–2669 |doi=10.1002/macp.1988.021891113}}</ref>
|Section1 = {{Chembox Identifiers
|CASNo_Ref = {{cascite|changed|??}}
|CASNo = 25067-58-7
|ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
|ChemSpiderID = none
}}
|Section2 = {{Chembox Properties
|Formula = {{chem2|[C2H2]_{''n''} }}
|Solubility = insoluble}}
|Section7 = {{Chembox Hazards
|GHSPictograms = {{GHS flame}}
|HPhrases = {{H-phrases|}}
|PPhrases = {{P-phrases|}}
}}
|Section3 = {{Chembox Related
|OtherCompounds = [[Acetylene]] gas (monomer)
}}
}}

'''Polyacetylene''' ([[IUPAC]] name: '''polyethyne''') usually refers to an [[organic polymer]] with the [[repeating unit]] {{chem2|[C2H2]_{''n''} }}. The name refers to its conceptual construction from [[polymerization]] of [[acetylene]] to give a chain with repeating [[olefin]] groups. This compound is conceptually important, as the discovery of polyacetylene and its high [[Ionic conductivity (solid state)|conductivity]] upon [[doping (semiconductor)|doping]] helped to launch the field of organic [[conductive polymer]]s. The high electrical conductivity discovered by [[Hideki Shirakawa]], [[Alan Heeger]], and [[Alan MacDiarmid]] for this polymer led to intense interest in the use of organic compounds in [[microelectronics]] ([[organic semiconductor]]s). This discovery was recognized by the [[Nobel Prize in Chemistry]] in 2000.<ref>{{cite journal |doi=10.1103/RevModPhys.73.681 |title=Nobel Lecture: Semiconducting and metallic polymers: The fourth generation of polymeric materials |year=2001 |last1=Heeger |first1=Alan |journal=Reviews of Modern Physics |volume=73 |issue=3 |pages=681–700 |bibcode=2001RvMP...73..681H |doi-access=free}}</ref><ref name="Nobel Prize">{{cite web |url=https://www.nobelprize.org/prizes/chemistry/2000/summary/ |title=The Nobel Prize in Chemistry 2000}}</ref> Early work in the field of polyacetylene research was aimed at using doped polymers as easily processable and lightweight "plastic metals".<ref name=Grubbs/> Despite the promise of this polymer in the field of conductive polymers, many of its properties such as instability to air and difficulty with processing have led to avoidance in commercial applications.

Compounds called polyacetylenes also occur in nature, although in this context the term refers to [[polyyne]]s, compounds containing multiple acetylene groups ("poly" meaning ''many''), rather than to chains of [[olefin fiber|olefin]] groups ("poly" meaning ''polymerization of'').<ref>{{cite journal |doi=10.1016/j.plipres.2008.02.002 |volume=47 |title=Biosynthesis and function of polyacetylenes and allied natural products |year=2008 |journal=Progress in Lipid Research |pages=233–306 |last1=Minto |first1=Robert E. |issue=4 |pmid=18387369 |pmc=2515280}}.</ref>