The Polymer Society of Korea

서동주 (서울대학교)

이종찬 (서울대학교)

We report a novel 2D covalent crystalline framework, C2O, composed of carbon and oxygen in a 2:1 molar ratio with embedded crown ether-like cavities. C2O is synthesized on a gram scale and shows excellent stability in acidic, basic, and organic solvent conditions.

The framework strongly coordinates with K⁺ from KI, enhancing I⁻ nucleophilicity and dramatically improving catalytic activity for CO₂ cycloaddition with epoxides. With KI, C2O boosts CO₂ conversion from 5.7% to 99.9% (epichlorohydrin) and from 2.9% to 74.2% (allyl glycidyl ether, AGE).

Moreover, C2O possesses both electrophilic and nucleophilic edge sites, allowing for post-synthetic modification. Reactions with AGE or ethoxyethylamine yield C2O-AGE and C2O-EEA, achieving even higher CO₂ conversion (97.2% and 99.9%, respectively).

This chemically stable, scalable, and functionally tunable crown ether-based framework offers a promising platform for advanced catalytic applications.