English
The exploration of the structure of three-dimensional covalent organic frameworks (3D COFs) is of great significance for the development of COF materials. Unlike MOFs with diverse structures and multiple connectivity (3-24), the valences of 3D COFs are now limited to 4, 6, and 8. Therefore, exploring structured building blocks with higher connectivity is the only way to expand the scope of 3D COF structures. Here, we have designed and synthesized for the first time a 12 linked triptycene-12-CHO precursor with 12 symmetrical aldehyde groups, which is also the highest reported valence to date. Based on this unique 12 link structure, we have successfully prepared a novel 3D COF with lnj topology (referred to as 3D lnj COF). The synthesized 3D COF has honeycomb like main pores and permanent pores, with a Brunauer Emmett Teller surface area of 1159.6 m2 g-1. This work not only provides a strategy for synthesizing precursors with high connectivity, but also provides inspiration for enriching the variety of 3D COFs.
