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Stable pseudo[3]rotaxanes with strong positive binding cooperativity based on shape-persistent aromatic oligoamide
Thomas A Sobiech1, Yulong Zhong1, Laura S Sánchez B2
1Department of Chemistry, University at Buffalo, the State University of New York, Buffalo, New York 14260, USA. bgong@buffalo.edu.
Chemical Communications (Cambridge, England)
|October 25, 2021
Summary
New macrocycles with C3-symmetry effectively bind guests, forming stable pseudo[3]rotaxanes. These systems exhibit significant enthalpic and entropic contributions, alongside strong positive binding cooperativity.
Area of Science:
- Supramolecular Chemistry
- Organic Chemistry
- Host-Guest Chemistry
Background:
- Aromatic oligoamide macrocycles are increasingly studied for their unique binding properties.
- Host-guest chemistry explores the interactions between molecular hosts and their guests.
Purpose of the Study:
- To synthesize and characterize novel C3-symmetric aromatic oligoamide macrocycles.
- To investigate the binding of a bipyridinium guest (G) within these macrocyclic hosts.
- To analyze the thermodynamic contributions (enthalpic and entropic) to the binding process.
Main Methods:
- Synthesis of C3-symmetric aromatic oligoamide macrocycles.
- Spectroscopic techniques (e.g., NMR) for characterization.
- Binding studies to determine stability constants and cooperativity.
- Thermodynamic analysis of binding events.
Main Results:
- Formation of compact pseudo[3]rotaxanes between the macrocycles and the bipyridinium guest.
- High binding stabilities were observed for the host-guest complexes.
- Significant enthalpic and entropic contributions were identified.
- Strong positive binding cooperativity was demonstrated.
Conclusions:
- The novel C3-symmetric macrocycles are effective hosts for bipyridinium guests.
- The observed high stabilities and cooperativity highlight the potential of these systems in supramolecular chemistry.
- The findings contribute to understanding the driving forces in host-guest complexation.
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