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A bistable [2]catenane switched by hetero-radical pairing interactions
Yang Zhang1, Qiong Chen, Yan Wang
1Department of Chemistry, Zhejiang University, Hangzhou 310027, P. R. China. lihao2015@zju.edu.cn.
Chemical Communications (Cambridge, England)
|October 6, 2020
Summary
Researchers synthesized a bistable [2]catenane using template-directed synthesis. This mechanically interlocked molecule switches between two states, driven by redox-triggered donor-acceptor and radical interactions.
Area of Science:
- Supramolecular Chemistry
- Mechanical Interlocking
- Click Chemistry
Background:
- Template-directed synthesis is crucial for constructing complex mechanically interlocked molecules.
- Donor-acceptor interactions and redox-responsive units are key to controlling molecular motion.
Purpose of the Study:
- To synthesize a bistable [2]catenane using template-directed synthesis and click chemistry.
- To investigate the redox-induced switching mechanism of the catenane.
Main Methods:
- Template-directed synthesis utilizing click chemistry.
- Redox titrations to analyze the electronic states of the catenane.
- Spectroscopic methods to confirm the structure and interactions.
Main Results:
- Successful synthesis of a bistable [2]catenane featuring cyclobis(paraquat-p-phenylene) (CBPQT4+) and a neutral macrocycle with 1,5-dioxynaphthalene (DNP) and naphthalene-1,4,5,8-bis(dicarboximide) (NDI) units.
- Demonstration of redox-induced switching: CBPQT4+ encircles DNP in the oxidized state via donor-acceptor interactions.
- Shuttling of the CBPQT2(•+) ring onto the NDI•− station in the reduced state, driven by coulombic-enhanced spin-pairing interactions.
Conclusions:
- The synthesized [2]catenane exhibits bistable behavior controlled by redox stimuli.
- The study highlights the potential of donor-acceptor and radical interactions in designing molecular switches.
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