Dynamic Molecular Invasion into a Multiply Interlocked Catenane.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Synthesis

Background:

• Catenanes are mechanically interlocked molecules with unique topologies.
• Phthalocyanines and porphyrins are macrocyclic compounds with diverse applications.
• Developing dynamic supramolecular architectures is crucial for advanced molecular devices.

Purpose of the Study:

• To synthesize a novel multiply interlocked catenane with a dynamic molecular topology.
• To investigate the ability of the catenane's nanospaces to accommodate guest molecules.
• To explore the control over molecular interactions within the supramolecular conjugate.

Main Methods:

• Synthesis of a phthalocyanine bearing four peripheral crown ethers.
• Quadruple interlocking with a cofacial porphyrin dimer bridged by alkylammonium chains.
• Photometric titration experiments to study guest inclusion phenomena.

Main Results:

• Successful synthesis of a multiply interlocked catenane with two tunable nanospaces.
• Demonstration of dynamic molecular invasion, allowing large molecules into the nanospaces.
• High-affinity intercalation of dianionic porphyrins into both nanospaces, confirmed by a two-step inclusion process.
• Switching off spin-spin interactions in a copper(II)-complexed catenane via porphyrin intercalation.

Conclusions:

• The novel catenane architecture enables dynamic control over guest inclusion.
• The adjustable nanospaces facilitate high-affinity binding of large guest molecules.
• This system offers a platform for developing responsive supramolecular materials and sensors.