Synthesis, Hole Doping, and Electrical Properties of a Semiconducting Azatriangulene-Based Covalent Organic Framework

作者：David W. Burke, Raghunath R. Dasari, Vinod K. Sangwan, Alexander K. Oanta, Zoheb Hirani, Chloe E. Pelkowski, Yongjian Tang, Ruofan Li, Daniel C. Ralph, Mark C. Hersam, Stephen Barlow, Seth R. Marder, William R. Dichtel · 发表于：Journal of the American Chemical Society · 年份：2023 · DOI：10.1021/jacs.2c12371 · 被引用次数：59 · 研究领域：Covalent Organic Framework Applications、Metal-Organic Frameworks: Synthesis and Applications、Graphene research and applications

Two-dimensional covalent organic frameworks (2D COFs) containing heterotriangulenes have been theoretically identified as semiconductors with tunable, Dirac-cone-like band structures, which are expected to afford high charge-carrier mobilities ideal for next-generation flexible electronics. However, few bulk syntheses of these materials have been reported, and existing synthetic methods provide limited control of network purity and morphology. Here, we report transimination reactions between benzophenone-imine-protected azatriangulenes (OTPA) and benzodithiophene dialdehydes (BDT), which afforded a new semiconducting COF network, OTPA-BDT. The COFs were prepared as both polycrystalline powders and thin films with controlled crystallite orientation. The azatriangulene nodes are readily oxidized to stable radical cations upon exposure to an appropriate p -type dopant, tris(4-bromophenyl)ammoniumyl hexachloroantimonate, after which the network’s crystallinity and orientation are maintained. Oriented, hole-doped OTPA-BDT COF films exhibit electrical conductivities of up to 1.2 × 10 –1 S cm –1, which are among the highest reported for imine-linked 2D COFs to date.