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Published on: April 26, 2024
Mechanochemical C-C bond stability as a function of substitution: a computational and experimental study
Oleg Gouli1, Hang Zhang1, Elisa Ivry1
1Schulich Faculty of Chemistry, The Resnick Sustainability Centre for Catalysis Technion - Israel Institute of Technology Haifa 3200008 Israel charles@technion.ac.il.
RSC Advances
|July 30, 2026
Summary
This study explores how substituents affect carbon-carbon bond stability in polymers using computational methods. Findings reveal structural features influencing mechanochemical recyclability and offer new experimental techniques for polymer mechanochemistry.
Area of Science:
- Polymer mechanochemistry
- Computational chemistry
- Materials science
Background:
- Homolytic C-C bond scission is common in polymer mechanochemistry, even when other bonds are weaker.
- C-C bond scission is often a side reaction but has potential for plastic recycling and C-C bond activation.
- Selective C-C bond scission is typically observed in strained or elongated bonds within cyclic or sterically hindered molecules.
Purpose of the Study:
- To systematically investigate the electronic and steric effects of substituents on the mechanical stability of unstrained C-C bonds.
- To identify structural motifs that influence the force required for C-C bond scission.
- To provide insights into the mechanochemical stability and recyclability of various polymer chemistries and introduce a new experimental protocol for evaluating mechanochemical selectivity.
Main Methods:
- Utilizing the constrained geometries simulate external force (CoGEF) computational method.
- Systematically exploring the impact of common substituents on C-C bond stability.
- Developing and applying a novel experimental protocol to assess mechanochemical selectivity in mechanophores lacking clear spectroscopic signals, using poly(phthalaldehyde) depolymerization as a model.
Main Results:
- Identified specific structural motifs and substituent effects that significantly alter the mechanical stability of unstrained C-C bonds.
- Quantified the bond scission forces, correlating them with electronic and steric factors.
- Demonstrated the utility of the new experimental protocol for evaluating mechanochemical selectivity in complex polymer systems.
Conclusions:
- Substituents play a crucial role in tuning the mechanochemical stability of C-C bonds in polymers.
- Understanding these structure-mechanics relationships is key to designing polymers for targeted mechanochemical applications, including recycling.
- The developed methods offer valuable tools for advancing the field of polymer mechanochemistry and materials design.
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