A luminescent silver-phosphine tetragonal cage based on tetraphenylethylene

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Coordination Chemistry

Background:

• Tetraphenylethylene (TPE) derivatives are known for their aggregation-induced emission (AIE) properties.
• Designing stable supramolecular structures with specific functionalities remains a challenge.
• Metal-ion coordination is a powerful tool for constructing complex molecular architectures.

Purpose of the Study:

• To synthesize and characterize a novel phosphine-based tetragonal cage using TPE-tetraphosphine and Ag(+) ions.
• To investigate the structural stability and fluorescence properties of the resulting cage in solution and solid states.
• To explore the potential of the TPE-P4 cage as a fluorescent sensor for guest molecules.

Main Methods:

• Self-assembly of a TPE-based tetraphosphine ligand with silver nitrate (AgNO3) in a suitable solvent.
• Structural characterization using X-ray crystallography, NMR spectroscopy, and mass spectrometry.
• Photophysical studies including fluorescence spectroscopy in solution and solid state, and sensing experiments with various anions and olefins.

Main Results:

• A novel tetragonal cage complex, TPE-P4, was successfully assembled and structurally confirmed.
• The TPE-P4 cage exhibits remarkable structural stability in both solution and solid states.
• The cage displays strong fluorescence in dilute solutions and aggregated states, with a notable turn-on fluorescence in dilute solutions.
• Sensing experiments demonstrated the potential of TPE-P4 as a fluorescent sensor for specific anions and olefin compounds, attributed to guest binding at the labile silver centers.

Conclusions:

• A robust phosphine-based tetragonal cage with AIE characteristics has been developed.
• The TPE-P4 cage demonstrates excellent stability and unique fluorescence behavior.
• The labile silver centers within the cage enable selective binding and detection of guest anions and olefins, highlighting its utility in chemical sensing applications.