Manipulating Aromaticity to Redirect Topochemical Polymerization Pathways
Topochemical polymerization (TCP) represents an essential route to create regio- and stereoregular polymers through solid-state transformations. Herein, we present an innovative strategy for controlling topochemical polymerization pathways by tailoring the terminal group aromaticity in the <i>para</i>-azaquinodimethane (AQM) ring system. Substituting phenyl groups with less aromatic furyl units extends significant spin density delocalization across the conjugated core upon thermal activation, inducing significant diradicaloid characters at furyl positions and enabling unconventional reactivities in both solution and solid states. Thermal treatment in toluene yields a unique cyclophane dimer formed via furyl-methine C-C coupling, confirmed by X-ray crystallography, while solid-state reactions produce polymers formed via both intercolumnar furyl-methine coupling and intracolumnar methine-methine coupling. The spin-center-directed mechanism underlying these transformations is validated through theoretical modeling and isotopic labeling experiments. This study highlights the prowess of aromaticity modulation in functional pro-aromatic systems, which enables the synthesis of polymers with main chain structures that are otherwise difficult to access.
Authors
- Haiyan Mao (ORCID: https://orcid.org/0000-0003-0591-1236)
- Tao Xia (ORCID: https://orcid.org/0000-0002-4989-4864)
- Rebecca Shu Hui Khoo
- Chongqing Yang (ORCID: https://orcid.org/0000-0002-2538-8545)
- Zhiyuan Huang (ORCID: https://orcid.org/0000-0002-7526-1585)
- Liang Z. Tan (ORCID: https://orcid.org/0000-0003-4724-6369)
- Sha Lai (ORCID: https://orcid.org/0000-0003-2346-4433)
- Ah‐Young Song (ORCID: https://orcid.org/0000-0001-7931-0148)
- Zhipeng Pei (ORCID: https://orcid.org/0000-0001-5628-7627)
- Jeffrey A. Reimer (ORCID: https://orcid.org/0000-0002-4191-3725)
- Michelle L. Coote (ORCID: https://orcid.org/0000-0003-0828-7053)
- Jian Zhang (ORCID: https://orcid.org/0000-0003-0274-0814)
- Chen Zhou (ORCID: https://orcid.org/0000-0002-6332-4198)
- Yi Liu (ORCID: https://orcid.org/0000-0002-3954-6102)
- Yunfei Wang (ORCID: https://orcid.org/0000-0001-7555-5308)
- Miao Qi (ORCID: https://orcid.org/0000-0003-2232-8739)
- Qingsong Zhang (ORCID: https://orcid.org/0000-0001-7893-2447)
Institutions
- Lawrence Berkeley National Laboratory (US)
- Flinders University (AU)
- Xiamen University (CN)
- Center for Nanoscale Science and Technology (US)
- Foundry (United Kingdom) (GB)
- Resonance Research (United States) (US)
- Advanced Light Source
- Molecular Foundry
- University of Southern Mississippi (US)
- University of California, Berkeley (US)
Publication Details
- Journal
- Journal of the American Chemical Society
- Published
- 2025-04-15
- DOI
- https://doi.org/10.1021/jacs.5c03077
- Citations
- 6
- Primary Topic
- Polydiacetylene-based materials and applications
- Type
- article
- Field-Weighted Citation Impact
- 5.62
Funders
- Australian Research Council
- Basic Energy Sciences