Nanographene-Based van der Waals Organic Framework With Permanent Porosity.

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Nanotechnology

Background:

• Porous crystalline materials typically require strong coordination or covalent bonds for structural integrity.
• Developing purely organic porous materials with high surface areas remains a significant challenge.

Purpose of the Study:

• To report a new C3-symmetric molecular nanographene (compound 1) that self-organizes into a permanently porous framework.
• To investigate the structural, adsorption, and emissive properties of this novel organic framework.

Main Methods:

• Single-crystal X-ray diffraction to determine molecular geometry and crystal packing.
• Nitrogen adsorption measurements at 77 K to assess porosity and surface area.
• Thermal analysis to evaluate stability.

Main Results:

• Compound 1 self-assembles into a 2D honeycomb structure stabilized by van der Waals interactions (π···π and C-H···π).
• Achieved a record Brunauer-Emmett-Teller (BET) surface area of 1108 m² g⁻¹, the highest for purely organic van der Waals frameworks.
• Exhibited aggregation-induced emission (AIE) and high thermal stability up to 290°C.

Conclusions:

• Designed nanographenes can form robust, porous frameworks using only weak interactions.
• This approach bypasses the need for metal nodes or covalent linkages, offering a new strategy for porous material design.
• The material shows promise for gas storage and other applications leveraging its high surface area and unique properties.