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Updated: Jun 13, 2026
06:55
Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
Quinoid-controlled bond-length alternation enables high-mobility non-fused π-conjugated polymers
Tsubasa Mikie1,2, Keitaro Iguchi1, Ryosuke Kamimura2
1Graduate School of Advanced Science and Engineering, Hiroshima University 1-4-1 Kagamiyama Higashi-Hiroshima Hiroshima 739-8527 Japan mikie@hiroshima-u.ac.jp iosaka@hiroshima-u.ac.jp.
Chemical Science
|June 12, 2026
Summary
High charge-carrier mobility in π-conjugated polymers can be achieved without fused rings by controlling quinoid resonance and bond-length alternation (BLA). This molecular design strategy enables efficient intrachain transport for advanced organic electronics.
Area of Science:
- Materials Science
- Organic Electronics
- Polymer Chemistry
Background:
- High charge-carrier mobility in π-conjugated polymers usually relies on fused-ring structures for planarity and π-π stacking.
- Conventional approaches often limit design flexibility and material properties.
Purpose of the Study:
- To investigate achieving high charge-carrier mobility in non-fused polymer backbones.
- To explore the role of quinoid resonance and bond-length alternation (BLA) in controlling charge transport.
- To demonstrate a new molecular design strategy for high-performance organic semiconductors.
Main Methods:
- Synthesized S-Pechmann (SP)-based polymers with systematically tuned quinoidal character by varying oligothiophene co-units.
- Analyzed the impact of quinoidal character on bond-length alternation (BLA) and π-electron delocalization.
- Fabricated and characterized organic field-effect transistors (OFETs) to measure charge-carrier mobility.
Main Results:
- Increasing quinoidal character suppressed BLA, enhancing π-electron delocalization and reducing effective carrier masses.
- Achieved ambipolar OFET characteristics with high mobilities: up to 4.4 cm2 V-1 s-1 for holes and 3.4 cm2 V-1 s-1 for electrons.
- High mobility was observed despite moderate crystallinity and unfavorable face-on orientation.
Conclusions:
- Quinoid-induced modulation of BLA is a key factor governing intrachain charge transport in conjugated polymers.
- Modulating BLA offers a viable strategy for designing high-mobility π-conjugated polymers beyond traditional fused-ring systems.
- This work provides a new molecular design approach for high-performance organic electronic devices.
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