Polyethine

Structural formula
	; trans -polyacetylene cis -polyacetylene ; ;
General
Surname	Polyethine
other names	Polyacetylene
CAS number	25067-58-7
Monomer	Ethine
Molecular formula of the repeating unit	C 2 H 2
Molar mass of the repeating unit	26.04 g mol −1
properties
Physical state	firmly
safety instructions
GHS labeling of hazardous substances	no classification available
	no classification available
H and P phrases	H: see above
	P: see above
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Polyethine (also polyacetylene , abbreviation PAC ) is a polymer of ethine . There are three polyacetylene isomers , the trans -Polyethin, the cis -Polyethin and the cis - cisoid polyacetylene, which is however unstable. Polyethine is an electrical insulator ; by doping can be a conductivity achieved by the silver , a metal having the best electrical conductivity, equal to. Doped polyethine was the first polymer on which electrical conductivity was observed ( conductive polymer ).

Doped (conductive) polyethine reacts with oxygen in air and thereby loses its conductivity. Because of this air instability it is of little importance nowadays; it was replaced by semiconductor polymers such as polypyrrole , polyaniline , polyphenylenevinylene , polyfluorene and polythiophene , which were discovered later .

Historical information

Giulio Natta polymerized ethyne for the first time to polyethine in 1958. Alan Heeger and Alan MacDiarmid from the USA and the Japanese Hideki Shirakawa showed in 1976 that doping the polyethine with oxidizing agents leads to a very strong increase in electrical conductivity. The three scientists received the Nobel Prize in Chemistry in 2000 for their work in the development of electrically conductive polymers.

Individual evidence

↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
↑ Werner Gans: The art of electrifying plastics. Nobel Prize in Chemistry 2000. In: Spectrum of Science. No. 12, 2000, pp. 16-19.
↑ Hideki Shirakawa, Edwin J. Louis, Alan G. MacDiarmid, Chwan K. Chiang, Alan J. Heeger: Synthesis of electrically conducting organic polymers: halogen derivatives of polyacetylene, (CH) x . In: J. Chem. Soc. Chem. Commun. No. 16 , 1977, pp. 578-580 , doi : 10.1039 / C39770000578 .
↑ CK Chiang, CR Fincher, YW Park, AJ Heeger, H. Shirakawa, EJ Louis, SC Gau, Alan G. MacDiarmid: Electrical Conductivity in Doped Polyacetylene . In: Physical Review Letters . tape 39 , no. 17 , 1977, pp. 1098-1101 , doi : 10.1103 / PhysRevLett.39.1098 .

[NV-1] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[2] Werner Gans: The art of electrifying plastics. Nobel Prize in Chemistry 2000. In: Spectrum of Science. No. 12, 2000, pp. 16-19.

[3] Hideki Shirakawa, Edwin J. Louis, Alan G. MacDiarmid, Chwan K. Chiang, Alan J. Heeger: Synthesis of electrically conducting organic polymers: halogen derivatives of polyacetylene, (CH) x . In: J. Chem. Soc. Chem. Commun. No. 16 , 1977, pp. 578-580 , doi : 10.1039 / C39770000578 .

[4] CK Chiang, CR Fincher, YW Park, AJ Heeger, H. Shirakawa, EJ Louis, SC Gau, Alan G. MacDiarmid: Electrical Conductivity in Doped Polyacetylene . In: Physical Review Letters . tape 39 , no. 17 , 1977, pp. 1098-1101 , doi : 10.1103 / PhysRevLett.39.1098 .