Two-stage directed self-assembly of a cyclic [3]catenane

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Materials Science

Background:

• Interlocked molecules exhibit unique properties based on their connectivity.
• Topologically complex structures like knots and catenanes are challenging synthetic targets due to 3D assembly requirements.

Purpose of the Study:

• To report a novel synthetic route for a cyclic [3]catenane.
• To demonstrate an advance in metal-templated self-assembly and selective imine exchange for complex molecular architectures.

Main Methods:

• Utilized five distinct building blocks for self-assembly.
• Formed a heteroleptic triangular framework of two joined Fe(II)3L3 circular helicates.
• Employed subcomponent exchange to link framework points and generate the catenane.

Main Results:

• Successfully synthesized a cyclic [3]catenane, a molecule comprising three mutually interpenetrating rings.
• Developed an unusual synthetic route involving metal-templated self-assembly.
• Demonstrated the efficacy of selective imine exchange for constructing topologically complex molecules.

Conclusions:

• The reported method advances the intricacy of metal-templated self-assembly.
• Selective imine exchange is a viable strategy for generating topologically complex products like cyclic [3]catenanes.
• This work provides a new pathway for synthesizing challenging interlocked molecular structures.