Motorized Macrocycle: A Photo-responsive Host with Switchable and Stereoselective Guest Recognition

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Photo-responsive host-guest systems are crucial for developing smart materials.
• Molecular rotary motors offer potential for light-controlled molecular functions.
• Switchable chiral recognition is a key challenge in supramolecular chemistry.

Purpose of the Study:

• To design and synthesize photo-responsive macrocyclic hosts incorporating molecular rotary motors.
• To achieve light-modulated, switchable chiral guest recognition.
• To explore the potential of these systems in creating dynamic materials.

Main Methods:

• Synthesis of macrocyclic hosts featuring first-generation molecular motors with oligoethylene glycol linkers.
• Utilizing light-driven unidirectional rotation of molecular motors to control host properties.
• Investigating host-guest interactions with ammonium salt guests using binding affinity and stereoselectivity measurements.

Main Results:

• Successful design of crown-ether-like macrocycles with intrinsic motor function.
• Demonstration of 1:1 host-guest complexation with ammonium salts enabled by motor rotation.
• Reversible modulation of binding affinity and stereoselectivity through light-induced switching of motor geometry and helicity.

Conclusions:

• Photo-responsive molecular motors can be integrated into macrocyclic hosts for switchable guest recognition.
• This approach offers a versatile strategy for constructing stimuli-responsive supramolecular systems.
• The developed system provides a foundation for advanced dynamic materials with tunable properties.