Calix[4]arene-Based Porous Organic Nanosheets

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Nanotechnology

Background:

• Calixarenes are versatile in supramolecular chemistry but challenging to integrate into well-defined 2D covalent materials due to their nonplanar structure.
• Previous efforts have been limited in creating structurally precise 2D covalent networks from calixarenes.

Purpose of the Study:

• To report the first synthesis of a structurally defined, porous, 2D calix[4]arene-based polymer (CX4-NS) as few-layer nanosheets.
• To characterize the material's structure and evaluate its performance in iodine vapor adsorption.

Main Methods:

• Solvothermal synthesis was employed to create the calix[4]arene-based 2D polymer (CX4-NS).
• Experimental techniques including atomic force microscopy (AFM) and transmission electron microscopy (TEM) were used for characterization.
• Theoretical calculations determined the lowest energy state and structural conformation.
• Iodine vapor adsorption experiments and molecular simulations were conducted to assess performance.

Main Results:

• Few-layer thick (3.52 nm) CX4-NS nanosheets were successfully synthesized.
• The material exhibits a porous structure with calixarenes in a 1,2-alternate conformation, forming a rhombic unit cell.
• A maximum iodine (I2) vapor adsorption capacity of 114 wt% was achieved.
• Molecular simulations confirmed the experimental adsorption results.

Conclusions:

• The study presents a novel method for constructing well-defined 2D covalent materials from calixarenes.
• The synthesized CX4-NS nanosheets show significant potential for gas adsorption applications, specifically for iodine vapor.
• The material demonstrates excellent regenerability and reusability, highlighting its practical applicability.