Visualizing supramolecular assembly behavior, stimulus response, and solid state emission of higher-order Pt²⁺...

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Photochemistry

Background:

• Development of efficient luminescent materials is crucial for advanced applications.
• Tuning emission properties through self-assembly offers a pathway to novel optical functionalities.
• Platinum(II) complexes and silver clusters are promising building blocks for functional supramolecular systems.

Purpose of the Study:

• To report the first highly efficient red tetramer aggregate with tunable emission.
• To investigate the self-assembly mechanism and stimuli-responsive luminescence of a cationic platinum(II) complex with a silver cluster anion.
• To explore potential applications in logic gates, sensing, and anticounterfeiting.

Main Methods:

• Synthesis of a cationic platinum(II) complex and a silver cluster anion.
• Spectroscopic analysis (UV-Vis, fluorescence) to study emission properties.
• X-ray crystallography, 1H NMR, computational calculations, and scanning electron microscopy (SEM) for structural and mechanistic insights.
• Investigation of self-assembly behavior under varying temperature, concentration, and solvent conditions.

Main Results:

• A highly efficient red tetramer aggregate with tunable emission (green to red) was successfully synthesized.
• Multicolor emission response was observed, attributed to the co-existence of monomer, excimer, and aggregation states.
• Isodesmic growth mechanism, temperature-dependent self-assembly, and well-defined nanostructures were identified.
• The system demonstrated sensitivity to external stimuli like concentration, solvent, and temperature.

Conclusions:

• The study presents a novel multi-stimuli responsive supramolecular system with tunable phosphorescence.
• The observed phenomena highlight the potential of self-assembly in controlling luminescence and creating functional materials.
• The developed material shows promise for applications in solid-state lighting, sensing, and anticounterfeiting technologies.