Intermolecular Anionic Mixed-Valence and π-Dimer Complexes of ortho-Pentannulated Bisazacoronene Diimide

Area of Science:

• Organic Chemistry
• Materials Science
• Electrochemistry

Background:

• Nitrogen-containing extended perylene diimides (PDIs) are crucial for organic electronics.
• AzaBenzannulatedPerylene Diimides (AzaBPDIs) and BisAzaCoroneneDiimides (BACDs) exhibit unique electronic properties.

Purpose of the Study:

• To synthesize and characterize ortho-pentannulated BACDs.
• To investigate the electrochemical reduction behavior of BACDs in non-aqueous solvents.
• To explore the formation of novel intermolecular species and their self-assembly.

Main Methods:

• Synthesis of nitrogen-containing extended PDIs via aza-benzannulation and Pd-catalyzed ortho-pentannulation.
• Spectroscopic analysis (UV/Vis, 1H NMR) and Atomic Force Microscopy (AFM) with Molecular Dynamics.
• Electrochemical techniques including Cyclic Voltammetry and real-time Spectroelectrochemistry.
• Theoretical calculations and electrochemical simulations.

Main Results:

• Successful synthesis of ortho-pentannulated BACDs with strong aggregation abilities.
• Observation of self-assembly into columnar aggregates in solution.
• Discovery of unprecedented intermolecular anionic mixed-valence (MV) and π-dimer species upon electrochemical reduction.
• Prominent splitting of the first reduction wave in Cyclic Voltammetry.

Conclusions:

• Ortho-pentannulated BACDs form stable intermolecular anionic MV and π-dimers in organic solvents.
• These findings highlight the tuneable nature of AzaBPDIs and BACDs for supramolecular materials.
• The study provides fundamental insights into supramolecular organic semiconductors for advanced electronic applications.