Neutral versus polycationic coordination cages: a comparison regarding neutral guest inclusion

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Self-assembled molecular containers are crucial for host-guest chemistry.
• Understanding the influence of charge on binding is essential for designing selective molecular hosts.
• Previous studies have explored cationic cages for molecular recognition.

Purpose of the Study:

• To synthesize and characterize a neutral self-assembled molecular container.
• To investigate the binding capabilities of this neutral host for fused polyaromatic substrates.
• To compare the inclusion properties of the neutral cage with a previously reported octacationic cage.

Main Methods:

• Synthesis of a neutral container using a concave π-extended tetrathiafulvalene (exTTF) ligand and a cis-Pd(dctfb)2(cod) complex.
• Characterization of the self-assembled structure.
• Evaluation of binding abilities with fused polyaromatic substrates.
• Comparative analysis of inclusion properties with an octacationic analogue.

Main Results:

• Successful synthesis of a neutral, self-assembled molecular host.
• Demonstrated good binding affinity for fused polyaromatic substrates.
• Established a basis for comparing binding in neutral versus cationic molecular cages.
• Provided insights into the effect of cavity charge on the binding of neutral guest molecules.

Conclusions:

• The neutral exTTF-based molecular container is an effective host for polyaromatic hydrocarbons.
• The study highlights the significant impact of the host's charge state on guest binding.
• This work paves the way for designing tunable molecular recognition systems by controlling cavity charge.