Increased halide recognition strength by enhanced intercomponent preorganisation in triazolium containing...

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Molecular Recognition

Background:

• Rotaxanes are mechanically interlocked molecules with potential applications in molecular machines and sensors.
• Anion recognition is crucial for various chemical and biological processes.

Purpose of the Study:

• To synthesize novel triazolium-based [2]rotaxanes.
• To investigate their anion recognition properties and selectivity.
• To understand the structural factors influencing binding affinity.

Main Methods:

• Synthesis of triazolium-based [2]rotaxanes via chloride anion templation.
• (1)H NMR titration experiments for anion binding studies.
• Computational DFT and molecular dynamics simulations (unconstrained and umbrella sampling).

Main Results:

• Successful synthesis of three [2]rotaxanes in good yields (40-57%).
• Demonstrated high selectivity for halide anions over acetate.
• Rotaxanes with shorter, rigid axles showed significantly higher binding affinities.

Conclusions:

• The size and rigidity of the axle component critically influence anion binding affinity in triazolium-based rotaxanes.
• Intercomponent preorganization plays a key role in enhancing receptor performance.
• Experimental findings are well-supported by computational simulations.