Cyclotris(paraquat-p-phenylenes)

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Synthesis

Background:

• Viologen-containing macrocycles are of interest for their redox properties and potential applications.
• Understanding the relationship between molecular structure and solid-state packing is crucial for materials design.

Purpose of the Study:

• To synthesize and characterize novel triangular, threefold symmetric, viologen-containing macrocycles.
• To investigate the solid-state structures and redox properties of these new compounds.
• To explore the influence of molecular geometry and intermolecular interactions on superstructure formation.

Main Methods:

• Synthesis of cyclotris(paraquat-p-phenylene) (CTPQT⁶⁺) and cyclotris(paraquat-p-1,4-dimethoxyphenylene) (MCTPQT⁶⁺).
• X-ray single-crystal structure determination to analyze three-dimensional packing.
• Solid-state characterization and redox property analysis.

Main Results:

• CTPQT⁶⁺ and MCTPQT⁶⁺ were successfully synthesized.
• X-ray crystallography revealed intricate 3D packing, with MCTPQT⁶⁺ forming nanometer-sized channels.
• MCTPQT^3(.+) demonstrated stacking between aromatic components and radical cations, enabling control over recognition motifs.

Conclusions:

• The synthesized viologen macrocycles exhibit complex solid-state superstructures dictated by geometry and weak interactions.
• MCTPQT⁶⁺ offers new possibilities for manipulating viologen radical cation recognition in the solid state.
• This work highlights the importance of supramolecular assembly in designing functional organic materials.