Supramolecular structures formed by calix[8]arene derivatives.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Synthesis

Background:

• Calix[8]arenes are macrocyclic compounds with a unique basket-like structure.
• Functionalization of calixarenes can lead to novel self-assembling materials.
• Hydrogen bonding plays a crucial role in the organization of molecular structures.

Purpose of the Study:

• To synthesize novel octamethoxy calix[8]arene derivatives with amide, urea, and imide functionalities.
• To investigate the self-assembly behavior of these synthesized calix[8]arene derivatives.
• To characterize the nanostructures formed by these derivatives.

Main Methods:

• Synthesis of functionalized octamethoxy calix[8]arenes via ipso nitration, reduction, and acylation.
• Scanning force microscopy (SFM) of spin-coated samples on graphite to observe self-assembly.
• Single-crystal X-ray diffraction to determine the precise molecular conformation and packing.

Main Results:

• Successful synthesis of octamethoxy calix[8]arenes bearing amide, urea, and imide groups.
• Observation of self-organization into tubular nanorods, driven by intermolecular hydrogen bonds between amide functionalities.
• Determination of a centrosymmetric conformation for the octanitro derivative using X-ray crystallography.

Conclusions:

• Functionalized octamethoxy calix[8]arenes can be controllably synthesized.
• These derivatives exhibit a propensity for self-assembly into ordered nanorods.
• Hydrogen bonding is a key interaction directing the formation of these supramolecular nanostructures.