Unlocking High-Performance Electrochemiluminescence in Supramolecular Coordination Frameworks via π-Bridge...

Area of Science:

• Materials Science
• Electrochemistry
• Photochemistry

Background:

• Aggregation-induced electrochemiluminescence (AIECL) enhances electrochemiluminescence (ECL) efficiency by reducing excited-state energy loss.
• Limited mechanistic understanding and structure-performance relationships hinder the rational design of high-efficiency AIECL emitters.

Purpose of the Study:

• To synthesize and investigate four supramolecular coordination frameworks (SCFs) with varied π-bridge structures for AIECL applications.
• To elucidate the structure-performance relationship and mechanistic pathways governing AIECL enhancement.

Main Methods:

• Synthesis of pyridine-functionalized tetraphenylethene (TPE) ligands and Pt(II) coordination to form SCFs.
• Electrochemical analysis, electron paramagnetic resonance (EPR), and density functional theory (DFT) calculations.
• Investigation of singlet oxygen (¹O₂) generation and radical amplification mechanisms.

Main Results:

• The synthesized TPE-SCFs generated excited-state species and singlet oxygen (¹O₂), enhancing cathodic ECL.
• π-bridge engineering narrowed the energy gap, facilitating intramolecular charge transfer and improving ECL.
• SCF aggregation promoted self-catalytic K₂S₂O₈ heterocleavage, boosting radical generation and ECL emission.

Conclusions:

• A dual enhancement mechanism involving π-bridge-mediated intramolecular charge transfer and aggregation-driven radical amplification was unveiled.
• This study provides valuable insights for the rational design of high-performance AIECL materials.
• The developed SCFs show potential for diverse applications requiring efficient ECL emitters.