Two-Dimensional Conjugated Covalent Organic Framework Films via Oxidative C–C Coupling Reactions at a Liquid–Liquid Interface

• Main Authors: Shaofei Wu, Hoa Phan, Jing Li, Haomin Xu, Xing Li, Dingguan Wang, Tun Seng Herng, Yi Han, Andrew Wee, Jun Ding, Jiong Lu, Jishan Wu
• Format: Article
• Language: English
• Published: Georg Thieme Verlag 2021-01-01
• Series: Organic Materials
• Subjects: covalent organic frameworks; oxidative c–c coupling; liquid–liquid interfaces; conducting polymers; polypyrroles
• Online Access: http://www.thieme-connect.de/DOI/DOI?10.1055/s-0041-1723767
• ISSN: 2625-1825

Abstract The construction of conjugated covalent organic frameworks (COFs) with strong C–C bond linkage remains a big challenge. Herein, we report a new strategy by using an oxidative C–C coupling reaction between electron-rich pyrrole rings at a liquid–liquid interface. Two threefold symmetric monomers containing three terminal pyrrole units were tested, and both gave two-dimensional conjugated COF films with good crystallinity. The bipyrrole units in the as-formed COFs are partially doped, which can be reduced to the neutral form by hydrazine and redoped by I2 vapor. The I2-doped films showed high conductivity (1.35 S/m). Meanwhile, the unpaired electrons exhibited moderate interlayer antiferromagnetic coupling.