Anionic Head Containing Oxacalix[2]arene[2]triazines: Synthesis and Anion-π-Directed Self-Assembly in Solution and...

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Materials Science

Background:

• Macrocyclic compounds like oxacalixarenes are versatile molecular scaffolds.
• Anion-π interactions are a key non-covalent force driving self-assembly.
• Designing molecules with specific functional groups is crucial for controlled self-organization.

Purpose of the Study:

• To synthesize novel oxacalix[2]arene[2]triazines functionalized with anionic groups.
• To investigate the self-assembly behavior of these macrocycles driven by anion-π interactions.
• To characterize the resulting aggregates using various spectroscopic and crystallographic techniques.

Main Methods:

• Synthesis of oxacalix[2]arene[2]triazines with carboxylate, sulfonate, sulfate, and phosphate groups.
• Nuclear Magnetic Resonance (NMR) spectroscopy to study aggregation in solution.
• Dynamic Light Scattering (DLS) to analyze aggregate size distribution.
• Mass Spectrometry (MS) for molecular weight determination of aggregates.
• X-ray crystallography to elucidate the solid-state assembly structure.

Main Results:

• Successful synthesis of functionalized oxacalix[2]arene[2]triazines.
• Evidence of oligomeric aggregate formation in solution confirmed by NMR, DLS, and MS.
• Crystal structures revealed the formation of chainlike assemblies.
• Anion-π interactions were identified as the primary driving force for the observed self-assembly.

Conclusions:

• The synthesized oxacalixarene triazines with anionic heads are effective dual building units for self-assembly.
• Anion-π interactions play a critical role in directing the formation of ordered supramolecular structures.
• These findings open avenues for designing novel self-assembling materials based on macrocyclic scaffolds.