An Interlocked Figure-of-Eight Molecular Shuttle

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Molecular Machines

Background:

• Interlocked molecules like rotaxanes are fundamental to molecular machines.
• Dibenzo-24-crown-8 (DB24C8) derivatives offer unique host-guest complexation properties.
• Click chemistry provides efficient and reliable methods for molecular assembly.

Purpose of the Study:

• To synthesize and characterize a novel figure-of-eight rotaxane molecular shuttle.
• To investigate the controlled shuttling of a DB24C8 unit along a molecular axle.
• To explore the creation of distinct conformational states through molecular manipulation.

Main Methods:

• Synthesis of a DB24C8 derivative with reactive chain extremities.
• Utilizing click chemistry for the formation of the rotaxane structure.
• Employing deprotonation and carbamoylation strategies to induce molecular shuttling.

Main Results:

• Successful synthesis and characterization of the figure-of-eight rotaxane.
• Demonstrated controllable shuttling of the DB24C8 moiety between ammonium and triazolium binding sites.
• Achieved two discrete co-conformational states by altering the binding interactions.

Conclusions:

• The developed rotaxane serves as a functional molecular shuttle with tunable states.
• This work advances the design principles for complex molecular machines.
• The strategy offers a pathway for creating dynamic molecular architectures.