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Redox-switchable resorcin[4]arene cavitands: molecular grippers
Igor Pochorovski1, Marc-Olivier Ebert, Jean-Paul Gisselbrecht
1Laboratorium für Organische Chemie, ETH Zürich, Hönggerberg, HCI, 8093 Zürich, Switzerland.
Journal of the American Chemical Society
|August 22, 2012
Summary
Novel diquinone-based cavitands switch between open and closed states via redox control, enabling guest binding and release. This molecular switch relies on redox-dependent intramolecular hydrogen bonding for stability.
Area of Science:
- Supramolecular Chemistry
- Organic Chemistry
- Materials Science
Background:
- Resorcin[4]arene cavitands are macrocyclic molecules with a well-defined cavity.
- Redox-responsive molecular systems offer dynamic control over chemical and physical properties.
Purpose of the Study:
- To synthesize and characterize diquinone-based resorcin[4]arene cavitands.
- To investigate their redox-switchable behavior for guest binding and release.
Main Methods:
- Synthesis of diquinone-based cavitands.
- X-ray crystallography to determine structural changes.
- Infrared (IR) and Nuclear Magnetic Resonance (NMR) spectroscopy to study hydrogen bonding.
Main Results:
- Cavitands were prepared and exhibited distinct open (kite) and closed (vase) conformations.
- The vase conformation is stabilized by intramolecular hydrogen bonding in the reduced hydroquinone state.
- Guest binding was observed in the closed state, with full release upon oxidation.
Conclusions:
- Diquinone-based cavitands function as redox-switchable hosts.
- Intramolecular hydrogen bonding is key to the switching mechanism.
- These systems demonstrate potential for controlled molecular recognition and delivery.
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