Supramolecular luminescent lanthanide dimers for fluoride sequestering and sensing

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Analytical Chemistry

Background:

• Lanthanide complexes are valuable in various applications due to their unique photophysical properties.
• Developing selective and sensitive methods for anion detection in aqueous media remains a significant challenge.

Purpose of the Study:

• To synthesize and characterize novel C2-symmetric cyclen-based lanthanide complexes.
• To investigate the supramolecular assembly of these complexes with fluoride anions in water.
• To explore the potential of these assemblies for luminescence-based fluoride sensing.

Main Methods:

• Synthesis and characterization of lanthanide (Eu, Tb, Yb) complexes.
• Spectroscopic studies (UV/Vis absorption, luminescence, NMR) to monitor supramolecular assembly.
• High-resolution mass spectrometry for structural elucidation.
• X-ray crystallography to determine the solid-state structure of the europium dimer.

Main Results:

• Formation of dinuclear supramolecular compounds with fluoride anions confined in the cavity.
• Structural analysis revealed stabilization through Eu-F-Eu bridges, π-stacking, and hydrogen bonding.
• Successful luminescence sensing of fluoride in aqueous solutions with a low detection limit of 24 nM.

Conclusions:

• The designed lanthanide complexes effectively self-assemble with fluoride ions in water.
• The supramolecular architecture provides a robust platform for sensitive fluoride detection.
• These findings highlight the potential of lanthanide-based supramolecular systems for analytical applications.