Editing Polyacetylene (section)

===Ring-opening metathesis polymerization===
Polyacetylene can be synthesized by [[ring-opening metathesis polymerisation]] (ROMP) from [[cyclooctatetraene]], a precursor that is more expensive but easier to handle than the [[acetylene]] [[monomer]].<ref>{{cite journal |last=Klavetter |first=Floyd L. |author2=Grubbs, Robert H. |title=Polycyclooctatetraene (Polyacetylene): Synthesis and Properties |journal=Journal of the American Chemical Society |date=1988 |volume=110 |issue=23 |pages=7807–7813 |doi=10.1021/ja00231a036|bibcode=1988JAChS.110.7807K }}</ref> This synthetic route also provides a means for introducing solubilizing groups to the polymer while maintaining the conjugation.<ref name=Grubbs>{{cite journal |last=Gorman |first=C. B. |author2=Ginsburg, E. J. |author3=Grubbs, R. H. |title=Soluble, Highly Conjugated Derivatives of Polyacetylene from the Ring-Opening Metathesis Polymerization of Monosubstituted Cyclooctratetraenes: Synthesis and the Relationship between Polymer Structure and Physical Properties |journal=Journal of the American Chemical Society |date=1993 |volume=115 |issue=4 |pages=1397–1409 |doi=10.1021/ja00057a024|bibcode=1993JAChS.115.1397G }}</ref> Polymers with linear groups such as ''n''-[[octyl]] had high conductivity but low solubility, while highly branched ''tert''-[[butyl]] groups increased solubility but decreased [[conjugated system|conjugation]] due to polymer twisting to avoid [[steric]] crowding. They obtained soluble and conductive polymers with ''sec''-butyl and neopentyl groups, because the [[methylene group|methylene]] (CH<sub>2</sub>) unit directly connected to the polymer reduces steric crowding and prevents twisting.<ref name=Grubbs/>
[[File:Modified Grubbs.png|thumb|center|upright 2.5|Grubbs route to polyacetylene]]