Synthesis of 12-Connected Three-Dimensional Covalent Organic Framework with lnj Topology
Zonglong Li, Guojie Xu, Chenxi Zhang, Shuan Ma, Yaxin Jiang, Hao Xiong, Guo Tian, Yanzhou Wu, Yen Wei, Xiao Chen, Yang Yang, Fei Wei
Abstract
The structural exploration of three-dimensional covalent organic frameworks (3D COFs) is of great significance to the development of COF materials. Different from structurally diverse MOFs, which have a variety of connectivity (3–24), now the valency of 3D COFs is limited to only 4, 6, and 8. Therefore, the exploration of organic building blocks with higher connectivity is a necessary path to broaden the scope of 3D COF structures. Herein, for the first time, we have designed and synthesized a 12-connected triptycene-based precursor (triptycene-12-CHO) with 12 symmetrical distributions of aldehyde groups, which is also the highest valency reported until now. Based on this unique 12-connected structure, we have successfully prepared a novel 3D COF with lnj topology (termed 3D-lnj-COF). The as-synthesized 3D COF exhibits honeycomb main pores and permanent porosity with a Brunauer–Emmett–Teller surface area of 1159.6 m 2 g –1 . This work not only provides a strategy for synthesizing precursors with a high connectivity but also provides inspiration for enriching the variety of 3D COFs.