One-Pot 'Click' Synthesis of Ring-in-Rings Complexes with Customizable π-Stacked Dyads.

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Materials Science

Background:

• Traditional synthesis of ring-in-rings complexes often results in poor solubility and low yields.
• Irreversible kinetically controlled reactions hinder the efficient formation of desired supramolecular structures.
• Need for improved methods to create complex molecular architectures with tunable properties.

Purpose of the Study:

• To develop an efficient one-pot aqueous synthesis for ring-in-rings complexes.
• To create customizable π-stacked dyads with improved solubility and yield.
• To establish a facile platform for exploring structure-function relationships in supramolecular assemblies.

Main Methods:

• Employed a strategy combining noncovalent preassembly with dynamic covalent bonding.
• Utilized cucurbit[8]uril (CB[8]) to induce a folded conformation in aldehyde-functionalized bis(phenylpyridinium) derivatives.
• Facilitated acylhydrazone condensation with aromatic dihydrazides, leading to the exclusive thermodynamic product.

Main Results:

• Achieved efficient one-pot aqueous synthesis of ring-in-rings complexes with high conversion and purity.
• Successfully synthesized diverse π-stacked dyads, confirmed by five distinct single-crystal structures showing dimeric cofacial stacking.
• Demonstrated that CB[8] complexation enhances the reaction's thermodynamic and kinetic favorability.

Conclusions:

• The developed method provides a thermodynamically controlled route to ring-in-rings complexes, overcoming limitations of kinetic control.
• The modular strategy allows precise tuning of photophysical properties by altering linker lengths and aromatic cores.
• This approach offers a versatile platform for designing advanced supramolecular materials and studying their structure-property correlations.