Large shape-persistent metal-invertible 15-Nsp(2)-donor-atom macrocycles functioning as trinucleating ligands.

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Coordination Chemistry

Background:

• Macrocyclic compounds are crucial in supramolecular chemistry for molecular recognition and catalysis.
• Nitrogen-rich heterocyclic compounds offer versatile coordination sites for metal ions.

Purpose of the Study:

• To synthesize a new class of [3 + 3] macrocycles with a high density of Nsp(2) donor atoms.
• To investigate the metal-binding capabilities and structural dynamics of the synthesized macrocycles.

Main Methods:

• Condensation reaction between 4,6-dihydrazinopyrimidines and 2,6-dicarbonylpyridines.
• Characterization of the resulting macrocycles using spectroscopic and analytical techniques.
• Complexation studies with metal ions under varying conditions.

Main Results:

• Successful synthesis of novel [3 + 3] macrocycles containing 15 Nsp(2) donor atoms.
• Nine Nsp(2) atoms are strategically positioned on the external circumference.
• The macrocycles demonstrated the ability to form trinuclear metal complexes.
• Observed macrocycle inversion, facilitating the transition of outer Nsp(2) atoms to inner positions.

Conclusions:

• A new family of N-rich macrocycles has been developed.
• These macrocycles exhibit unique structural flexibility and metal-binding properties.
• The findings open avenues for designing novel coordination compounds and supramolecular assemblies.