Interlocked 2D Covalent Organic Frameworks from Overcrowded Nodes

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Nanotechnology

Background:

• Interpenetration is a common feature in 3D covalent organic frameworks (COFs), but rare in 2D COFs due to π-stacking.
• Existing interlocked 2D COFs are typically derived from monomers with perpendicularly arranged aryl groups.

Purpose of the Study:

• To report the synthesis of a novel interlocked 2D COF using sterically overcrowded polycyclic aromatic hydrocarbons.
• To investigate the structural and electronic properties of the resulting interlocked 2D COF.

Main Methods:

• Synthesis of COFs from sterically overcrowded polycyclic aromatic hydrocarbon monomers.
• Characterization using microscopy, gas sorption, spectroscopy, and charge transport measurements.

Main Results:

• Successfully synthesized an interlocked 2D COF from sterically overcrowded aromatic monomers.
• Demonstrated the absence of interlayer π-stacking due to the interlocked architecture.
• Characterization confirmed the unique structure and properties, including charge transport.

Conclusions:

• Sterically overcrowded aromatic systems are effective monomers for generating mechanically interlocked 2D COFs.
• This strategy offers new possibilities for designing COFs with unconventional topologies and properties.
• The absence of π-stacking in these interlocked 2D COFs opens avenues for new applications.