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Driving Multi-Step Regioselectivity in On-Surface Polymer Synthesis by Molecular Coverage
Kalyan Biswas1, Alba García-Frutos1, Berta Álvarez2
1IMDEA Nanoscience, Campus de Cantoblanco, C/ Faraday 9, Madrid, 28049, Spain.
Angewandte Chemie (International Ed. in English)
|October 6, 2025
Summary
Researchers achieved regioselective polymerization on gold surfaces by controlling molecular coverage. This method allows precise tuning of polymer structure and dimensionality for advanced nanomaterials.
Area of Science:
- Surface Science
- Polymer Chemistry
- Nanomaterials Synthesis
Background:
- On-surface synthesis enables precise design of organic nanomaterials.
- Regioselective control in polymerization is crucial for tailoring material properties.
Purpose of the Study:
- To demonstrate a novel approach for regioselective polymerization on Au(111).
- To investigate the influence of molecular coverage on polymerization outcomes.
Main Methods:
- Utilized scanning tunneling microscopy (STM) and non-contact atomic force microscopy (nc-AFM).
- Employed density functional theory (DFT) calculations.
- Synthesized polymers from a dicyclopentaanthracene precursor on Au(111).
Main Results:
- Observed a molecular coverage-dependent regioselective homocoupling mechanism.
- Low coverage yielded 1D polymers via anti-configuration indenyl couplings.
- Half monolayer coverage resulted in quasi-1D staircase polymers.
- Higher coverages led to 2D porous networks driven by benzylic position activation.
Conclusions:
- Molecular coverage is a key factor in steering regioselectivity and polymer dimensionality.
- This work advances on-surface synthesis and polymer science by enabling controlled polymerization.
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