Self-assembled organometallic [12]metallacrown-3 complexes

Area of Science:

• Organometallic Chemistry
• Supramolecular Chemistry
• Coordination Chemistry

Background:

• Trinuclear metallamacrocyclic complexes are synthesized using arene ruthenium or Cp* rhodium precursors.
• Self-assembly of these complexes yields diastereoselective, racemic mixtures with specific configurations.

Purpose of the Study:

• To synthesize and characterize novel trinuclear metallamacrocyclic complexes.
• To investigate their ionophoric properties for alkali metal cations.
• To explore electrochemical and colorimetric detection methods for Li+ and Na+.

Main Methods:

• Reaction of [(arene)RuCl2]2 or [Cp*RhCl2]2 with 3-hydroxy-2-pyridone derivatives.
• Isolation and characterization of mononuclear intermediates and trinuclear macrocycles.
• Single crystal X-ray diffraction analysis.
• Electrochemical and colorimetric detection assays.
• Computational studies on related crown complexes.

Main Results:

• Synthesis of diastereoselective trinuclear metallamacrocycles with Ru or Rh centers.
• Demonstrated potent ionophore activity for Li+ and Na+, with negligible affinity for K+.
• Selective binding of Li+ or both Li+/Na+ depending on the pi-ligand.
• Electrochemical detection shows a >300 mV potential shift upon ion binding.
• Successful colorimetric detection of Li+ and Na+.

Conclusions:

• The synthesized metallamacrocycles are effective ionophores for Li+ and Na+.
• Selectivity is tunable based on the pi-ligand.
• Electrochemical and colorimetric methods provide sensitive detection of these alkali metals.