Three-Dimensional Covalent Organic Frameworks with jcg Topology Based on a Trinodal Strategy
Haorui Zheng, Jie Ji, Yusran Yusran, Jianhong Chang, Fengqian Chen, Zitao Wang, Jinquan Suo, Jie Zhang, Hui Li, Dan Zhao, Valentin Valtchev, Shilun Qiu, Qianrong Fang
Abstract
The development of three-dimensional (3D) covalent organic frameworks (COFs) holds significant promise for various applications, but the conventional uninodal or binodal design strategies limit their structural diversity. In this work, we present a novel trinodal strategy for the synthesis of 3D COFs featuring both microporous and mesoporous nanochannels. Using powder X-ray diffraction (PXRD), computational simulations, and high-resolution transmission electron microscopy (HR-TEM), we demonstrate that employing an 8-c building block with reduced symmetry, which can be considered as 4- and 3-connected subunits, along with planar 4-c building blocks, results in an unprecedented [4 + 3 + 4]-c jcg net. This structure features rare saddle-shaped eight-membered rings and mirror-symmetrical chains. Furthermore, the incorporation of chromophore pyrene and redox-active triphenylamine components, coupled with structural conjugation, imparts tunable photophysical and electronic properties to these COFs, making them promising candidates for photocatalytic H 2 O 2 production. This work highlights the potential of the trinodal strategy in creating intricate COF architectures and enhances their applicability in heterogeneous photocatalysis.