Conducting Polymers:
Alkynes are hydrocarbons which contain a carbon-carbon triple bond, e.g. ethyne (C2H2):
H - C
C -
H.
When ethyne is polymerised, the product contains alternating single and double bonds. Due to geometrical isomerism, two forms of polyethyne are produced: cis-polyethyne and trans-polyethyne. By using a Ziegler-Natta catalyst it was possible to produce just the cis form which on warming was found to conduct electricity.