Hexatopic Vertex-Directed Approach to Vinylene-Linked Covalent Organic Frameworks with Heteroporous Topologies
Zixing Zhang1, Shuai Bi1, Fancheng Meng1
1School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China.
Abstract:
A D3-symmetric hexatopic monomer was first prepared by attaching the three-fold ditopic moiety 2,6-dimethylpyridine to the meta-positions of a phenyl ring. It was further condensed at its six pyridylmethyl carbons with linear ditopic aromatic dialdehydes, resulting in two vinylene-linked COFs with heteroporous topologies, as revealed by powder X-ray diffraction (PXRD), nitrogen sorption, and pore-size distribution analyses, as well as transmission electron microscopy (TEM) image. The linear- and cross-conjugations, respectively, arising from the 2,6-linked pyridines and meta-linked phenylenes in the hexatopic nodes rendered the resultant COFs with well-patterned π-delocalization, allowing for efficiently catalyzing the bromination of aromatic derivatives with the pore-size-dependent conversion yields and regioselectivity under the irradiation of green light.
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