conjugated polymer

https://doi.org/10.1351/goldbook.08785
A polymer composed of molecules whose backbone is a sequence of alternating single and multiple bonds:
where RA1 and RA2 are each hydrogen, alkyl, aryl or heteroaryl and Ar is arenediyl (formerly: arylene) or heteroarenediyl (formerly: heteroarylene).
Notes:
  1. Overlaps of neighboring π-orbitals across intervening σ-bonds in a conjugated molecule results in delocalization of π-electrons along the molecule backbone. This effect which, however, is limited by Peierls distortion gives the electric conductivity to conjugated polymers.
  2. Conjugated polymers are mostly linear or branched polymers. However, they can also have a dendritic, hyperbranched, network, rotaxane or metallo-supramolecular chain architecture.
  3. Polymers such as polysilanes, polygermanes and polystannanes with significantly occupied LUMO orbitals due to low bandgap energy and thus show the delocalization of electrons sometimes called σ-conjugated polymers.
Source:
PAC, 2022, 94, 15. (Glossary of terms relating to electronic, photonic and magnetic properties of polymers (IUPAC Recommendations 2021)) on page 20 [Terms] [Paper]