Antiaromatic Covalent Organic Frameworks Based on Dibenzopentalenes

Area of Science:

• Materials Science
• Organic Chemistry
• Electrochemistry

Background:

• 4n π systems, despite instability, offer unique optical and electronic properties.
• Dibenzopentalene (DBP) stabilizes antiaromaticity while retaining amphoteric redox behavior and a small HOMO-LUMO gap.
• Challenges exist in using discrete DBP molecules or polymers in devices due to solubility and surface area limitations.

Purpose of the Study:

• To synthesize the first antiaromatic framework materials.
• To explore the potential applications of these novel materials in organic devices.
• To establish antiaromaticity as a new design principle for functional framework materials.

Main Methods:

• Synthesis of three highly crystalline and porous covalent organic frameworks (COFs) based on DBP.
• Characterization of COF properties, including conductivity and photoconductivity.
• Evaluation of COF performance as positive electrode materials in Li-organic batteries.

Main Results:

• Successful synthesis of the first antiaromatic framework materials (DBP-based COFs).
• DBP-based COF films demonstrated conductivity (4 × 10⁻⁸ S cm⁻¹) upon doping and exhibited photoconductivity.
• Application as positive electrodes in Li-organic batteries showed enhanced performance with a discharge capacity of 26 mA h g⁻¹ at 3.9 V vs. Li/Li⁺.

Conclusions:

• Antiaromaticity can be effectively utilized as a design principle for advanced framework materials.
• DBP-based COFs offer a promising platform for high-performance organic electronic devices and energy storage.
• The developed COFs overcome limitations of discrete molecules, enabling bulk material applications.