Tailored charge-neutral self-assembled L₂Zn₂ container for taming oxalate

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Analytical Chemistry

Background:

• Dicarboxylic acids are vital in biological processes, and detecting them, especially oxalate, is crucial due to its disease associations.
• Oxalate recognition by metal-driven self-assemblies (metallocages/containers) is understudied despite their advantages over organic receptors.
• Oxalate's strong ligand properties pose a stability risk to metal-driven assemblies, as it can displace ligands.

Purpose of the Study:

• To design and synthesize a stable, charge-neutral zinc(II)-based metallocontainer capable of selectively recognizing oxalate.
• To investigate the binding affinity and selectivity of the metallocontainer for oxalate against other dicarboxylates.
• To demonstrate the potential of modular receptor design for challenging analyte recognition.

Main Methods:

• Synthesis of a charge-neutral zinc(II)-based metallocontainer.
• Spectroscopic and binding studies to determine oxalate binding affinity and selectivity.
• Assessment of receptor stability in the presence of oxalate and competing dicarboxylates.

Main Results:

• A stable, charge-neutral zinc(II)-metallocontainer was successfully developed.
• The metallocontainer exhibited selective binding of oxalate in a 1:1 ratio with a high binding constant (log K = 4.39).
• The receptor maintained its structural integrity upon binding oxalate, demonstrating resistance to decomposition.

Conclusions:

• Modular design is key for creating tailored hosts capable of recognizing challenging, competitive analytes like oxalate.
• The developed zinc(II)-metallocontainer represents a significant advancement in selective oxalate detection.
• This work paves the way for new strategies in supramolecular chemistry for sensing biologically relevant anions.