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

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 I2vapor. The I2-doped films showed high conductivity (1.35 S/m). Meanwhile, the unpaired electrons exhibited moderate interlayer antiferromagnetic coupling.