Supramolecular macrocycles reversibly assembled by Te(…)O chalcogen bonding

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Materials Science

Background:

• Organic molecules with heavy main-group elements often form supramolecular assemblies.
• Halogen bonding is a well-studied interaction, but well-defined cyclic structures are rare.
• Previous research focused on dimers or extended structures, leaving a gap in understanding discrete macrocycles.

Purpose of the Study:

• To investigate the self-assembly of heterocycles linked by chalcogen-centered interactions.
• To synthesize and characterize genuine macrocyclic species from organic molecules.
• To explore the potential applications of these novel supramolecular structures.

Main Methods:

• Synthesis of 3-methyl-5-phenyl-1,2-tellurazole 2-oxide.
• Characterization of supramolecular aggregates using Nuclear Magnetic Resonance (NMR) spectroscopy.
• Crystallographic analysis to determine aggregate structures.

Main Results:

• Oligomeric aggregates, including cyclic tetramers and hexamers, and a helical polymer, were successfully assembled.
• The building blocks are connected via Te(…)O-N bridges in all observed aggregates.
• NMR studies confirmed the persistence of cyclic aggregates in solution.

Conclusions:

• Novel macrocyclic structures were formed through chalcogen-centered interactions.
• These self-assembled macrocycles exhibit stability in solution.
• The structures demonstrate potential as coordination complexes, fullerene receptors, and hosts for small molecules.