Metal-macrocycle framework (MMF): supramolecular nano-channel surfaces with shape sorting capability.

Area of Science:

• Supramolecular chemistry
• Nanotechnology
• Materials science

Background:

• Hollow nanostructures offer tunable interior geometries for chemical functionalization.
• Designing reaction centers within nanostructures is crucial for controlled chemical processes.

Purpose of the Study:

• To report a novel metal-macrocycle framework (MMF) capable of forming nanochannels with specific guest binding pockets.
• To demonstrate the selective encapsulation and sorting of aromatic molecules and optical isomers within these nanochannels.

Main Methods:

• Synthesis of a metal-macrocycle framework (MMF) forming single-crystalline nanochannels.
• Crystal-soaking experiments to investigate guest molecule encapsulation.
• Analysis of selective capture of constitutional isomers (dibromobenzene) and optical isomers ((1R/1S)-1-(3-chlorophenyl)ethanol).

Main Results:

• The MMF formed nanochannels with five distinct enantiomeric pairs of guest binding pockets.
• High site selectivity was achieved in encapsulating aromatic molecules, including constitutional isomers.
• Diastereoselective inclusion of optical isomers into specific binding pockets was observed.
• Demonstrated the ability to replace trapped molecules, allowing for interior wall modification.

Conclusions:

• MMFs provide a platform for steric design of interior reaction centers.
• The selective guest uptake capabilities enable regioselective and stereoselective reactions within nanochannels.
• This strategy offers potential for advanced molecular sorting and controlled chemical synthesis.