Reversible Structural Transformation Between a Hopf Link and a Solomon Link.

Area of Science:

• Supramolecular Chemistry
• Chemical Synthesis
• Materials Science

Background:

• Molecular topology explores the properties of molecules that are invariant under continuous deformation.
• Constructing complex topological structures like links requires precise control over molecular assembly.
• Metal ions are often employed as templates to direct the formation of specific supramolecular architectures.

Purpose of the Study:

• To demonstrate the reversible topological transformation between Hopf and Solomon links.
• To utilize the chemical reactivity of silver(I) ions for templating and topological control.
• To investigate the role of metal-ion coordination in directing self-assembly and topological changes.

Main Methods:

• Template-free self-assembly of semirigid ligands to form macrocycles and Hopf links.
• Introduction of silver(I) ions to induce topological transformation into Solomon links.
• Reversal of topological transformation via reduction of silver(I) ions or reaction with chloride ions.
• Metal-ion-templated assembly using bipyridyl ligands and Cp*Rh acceptors.

Main Results:

• Successful synthesis of macrocycles and Hopf links via self-assembly.
• Demonstration of reversible topological transformation between Hopf and Solomon links mediated by Ag(I) ions.
• Observation of topological transformation reversal upon Ag(I) ion reduction or reaction with chloride ions.
• Formation of both Solomon and Hopf links through metal-ion templating, with Solomon links transforming into Hopf links over time.

Conclusions:

• Silver(I) ions can template the construction of Solomon links.
• A novel, reversible topological transformation process between Hopf and Solomon links has been achieved.
• This work provides a new method for dynamic control over molecular topology using metal ions.