Cascade Assembly of Pillar[5]arene-Based Supramolecules Formed by Hexahydrogen Bonding and Host–Guest Interactions

Supramolecular aggregates constructed through multiple noncovalent interactions have garnered significant attention across various fields due to their modular and controllable assembly methods. In this study, we introduce a novel approach to modulate the hydrophilicity and hydrophobicity of supramolecular systems by incorporating structurally diverse molecules through hexahydrogen bonding interactions in a polar solvent. To investigate the synergistic effects of host-guest interactions and hydrogen bonding on the formation of supramolecular aggregates, molecules of Hamilton wedge-functionalized pillar[5]arene (<b>H</b>_<b>1</b>), barbituric acid derivatives with hydrophilic or hydrophobic chains (<b>C</b>_<b>1-2</b>), and a guest molecule (<b>G</b>) featuring a tetraphenylethylene (TPE) core were designed and synthesized. Two types of supramolecular aggregates, <b>H</b>_<b>1</b><b>C</b>_<b>1</b><b>G</b> and <b>H</b>_<b>1</b><b>C</b>_<b>2</b><b>G</b>, were constructed via orthogonal two-step assembly, resulting in a diverse range of molecular aggregate morphologies in both nonpolar and polar solvents. Ordered nanosheets and vesicle structures were displayed by aggregate <b>H</b>_<b>1</b><b>C</b>_<b>1</b><b>G</b> with a hydrophobic chain and aggregate <b>H</b>_<b>1</b><b>C</b>_<b>2</b><b>G</b> with a hydrophilic chain, through hydrophilic/hydrophobic and π-π stacking interactions. Interestingly, toxic environmental pollutants such as succinonitrile, hexanedinitrile, and methylviologen were effectively detected by fluorescent probe <b>H</b>_<b>1</b><b>C</b>_<b>1</b><b>G</b> with high sensitivity and selectivity. Furthermore, the coassemblies of <b>H</b>_<b>1</b><b>C</b>_<b>2</b><b>G</b> and Nile red exhibit FRET effects and are sensitive to acid, enabling acid-sensitive information encryption. The findings of this study offer new insights into the facile construction of functionalized supramolecular aggregates with various morphologies for practical applications of supramolecular soft materials.