Molecules at close range: encapsulated solvent molecules in pyrogallol[4]arene hexameric capsules

Area of Science:

• Supramolecular Chemistry
• Nanotechnology

Background:

• Pyrogallol[4]arenes self-assemble into hexameric capsules.
• These capsules possess large internal cavities suitable for molecular encapsulation.
• Such systems are explored as potential nanoreactors.

Purpose of the Study:

• To investigate the encapsulation behavior of pyrogallol[4]arene capsules.
• To analyze the interaction and dynamics of co-encapsulated guest molecules.
• To explore the influence of encapsulation on spectroscopic properties.

Main Methods:

• Synthesis of pyrogallol[4]arene hexameric capsules.
• Nuclear Magnetic Resonance (NMR) spectroscopy for analyzing encapsulated molecules.
• Study of co-encapsulation of benzene and chloroform.

Main Results:

• Hexameric capsules effectively encapsulate guest molecules like benzene and chloroform.
• Complex 1H NMR spectra indicate that encapsulated molecules reside in slightly different microenvironments within the capsules.
• Co-encapsulation of benzene and chloroform is favored.
• An enhanced Anisotropic Solute-Induced Shift (ASIS) effect was observed for the co-encapsulated complex.

Conclusions:

• Pyrogallol[4]arene capsules function as nanoreactors capable of encapsulating small molecules.
• The observed NMR complexity highlights the dynamic and heterogeneous nature of guest molecule trapping.
• Co-encapsulation strategies can enhance molecular interactions and spectroscopic phenomena within these nanoreactors.