These carbon–carbon double bonds interact in a process known as conjugation, resulting in some unusual optical properties.
The following polyenes are used as antimycotics for humans: amphotericin B, nystatin, candicidin, pimaricin, methyl partricin, and trichomycin.
Normally alkenes absorb in the ultraviolet region of a spectrum, but the absorption energy state of polyenes with numerous conjugated double bonds can be lowered such that they enter the visible region of the spectrum, resulting in compounds which are coloured (because they contain a chromophore).
Polyacetylene, which partially oxidized or reduced, exhibits high electrical conductivity.
[citation needed] Recent research at the Weizmann Institute and Aix-Marseille University showed a clear transition between ionic and electronic conductivity with increasing UV dose over 30 hours.