3D Covalent Organic Frameworks from Twistable Building Block Toward an Unprecedented ibd-r Topology for Efficient
Xilin Li1, Tongyi Zhao1, Yali Sun1
1Department of Chemistry, State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, China.
Abstract:
Owing to the limited diversity of structural topologies and pore features, it remains a tremendous challenge to elaborately design and synthesize three-dimensional covalent organic frameworks (3D COFs) for efficient gas separation. In this study, we present a series of isoreticular 3D COFs using [6 + 4] design strategy based on a designed 6-coordinated (6-c) building block with twistable D3-symmetric configuration and three different rectangular building blocks, named JUC-320, -321, and -322, respectively. The torsional flexibility of 6-c building blocks enables the targeted network to adopt an unprecedented self-catenated ibd-r topology with reduced pore sizes. Remarkably, these COFs exhibit exceptional performances in C3H6/C2H4 separation with high adsorption ratios and selectivities. Dynamic breakthrough experiments further confirmed their ability to efficiently separate C3H6/C2H4 mixtures (30/70, v/v), yielding polymer-grade C2H4 (>99.99%). This work offers a useful strategy for constructing 3D COFs with unprecedented topologies and porous architectures toward efficient gas separation.
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