Title: conjugated polymer
Long Title: IUPAC Gold Book - conjugated polymer
DOI: 10.1351/goldbook.08785
Status: current

Definition
A polymer composed of molecules whose backbone is a sequence of alternating single and multiple bonds:  where \(\ce{R^{1}}\) and \(\ce{R^{2}}\) are each hydrogen, alkyl, aryl or heteroaryl and Ar is arenediyl (formerly: arylene) or heteroarenediyl (formerly: heteroarylene).

Notes
1) Overlaps of neighboring \(\ce{\uppi\mbox{-}orbitals}\) across intervening \(\ce{\upsigma\mbox{-}bonds}\) 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 \(\ce{\uppi\mbox{-}conjugated polymers}\).

Related Terms
- delocalization of π-electrons: https://goldbook.iupac.org//terms/view/08789
- polysilanes: https://goldbook.iupac.org//terms/view/08899

Source
- PAC, 2022, 94, 15. 'Glossary of terms relating to electronic, photonic and magnetic properties of polymers (IUPAC Recommendations 2021)' on page 20 (https://doi.org/10.1515/pac-2020-0501)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/08785/html
- json: https://goldbook.iupac.org/terms/view/08785/json
- xml: https://goldbook.iupac.org/terms/view/08785/xml

Citation: Citation: 'conjugated polymer' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.08785
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Accessed: 2026-04-18T09:11:10+00:00