Multiple threading of a triple-calix[6]arene host.

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Macrocyclic Chemistry

Background:

• Calix[6]arenes are macrocyclic compounds with unique structural properties.
• Multiple-threading in supramolecular chemistry allows for complex architectures.
• Dialkylammonium compounds serve as suitable guests for macrocyclic hosts.

Purpose of the Study:

• To synthesize and characterize a novel triple-calix[6]arene derivative.
• To investigate the multiple-threading capabilities of the synthesized derivative with dialkylammonium axles.
• To explore the formation of pseudo[n]rotaxanes and their stereoselectivity.

Main Methods:

• Synthesis of the triple-calix[6]arene derivative.
• 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy.
• Diffusion Ordered Spectroscopy (DOSY) and Electrospray Ionization-Fourier Transform Ion Cyclotron Resonance Mass Spectrometry/Mass Spectrometry (ESI-FT-ICR MS/MS).

Main Results:

• Successful synthesis of the triple-calix[6]arene derivative (6).
• Demonstration of multiple-threading, forming pseudo[2]rotaxane, pseudo[3]rotaxane, and pseudo[4]rotaxane complexes.
• Evidence of stereoselective formation of endo-alkyl pseudo[n]rotaxane stereoisomers using directional axles.

Conclusions:

• The synthesized triple-calix[6]arene derivative acts as a versatile host for multiple-threading.
• The study elucidates the formation and characterization of complex pseudo[n]rotaxane structures.
• Stereochemical control in rotaxane synthesis is achievable through the use of directional guest molecules.