Construction of rigid amine-linked three-dimensional covalent organic frameworks for selectively capturing carbon dioxide.

A highly rigid amine-linked 3D COF was constructed from two orthogonal building blocks (spirobifluorene and bicarbazole) through a post-synthetic chemical reduction. The rigid 3D framework decreased the conformational flexibility of the amine linkages, and thus showed a fully preserved crystallinity and porosity. The amine moieties in the 3D COF afforded abundant chemisorptive sites for selectively capturing CO2.

Post-synthetic Fully π-Conjugated Three-Dimensional Covalent Organic Frameworks for High-Performance Lithium Storage.

A fully π-conjugated nitrogen-rich three-dimensional covalent organic framework (PYTRI-COF-2) containing both pyrazine and triazine units was prepared through a post-synthetic strategy. The imine linkages in the pre-prepared PYTRI-COF-1 were converted into heterocyclic quinoline by the Povarov reaction. The obtained PYTRI-COF-2 displayed high Li-ion storage capacity and excellent cycling stability when it was used as the lithium (Li)-ion battery electrode.