Fig. 1: Stable covalent organic frameworks with dense 1D nanochannels.
From: Confining H3PO4 network in covalent organic frameworks enables proton super flow
a Topology-guided synthesis of a stable crystalline mesoporous TPB-DMeTP-COF with a pore size of 3.36 nm. Inset shows the inducive and hyperconjugation effects of methyl groups that reduces the polarisation of C=N bonds, softens interlayer charge repulsion and yields an extremely stable framework. b Reconstructed structure of one hexagonal macrocycle (grey, C; blue, N; CH3 units and H are omitted for clarity). One hexagon has six Nin sites on each edge. c Reconstructed structure of a 1D channel; only 20 layers are shown. The 1D channel possesses six Nin chains with one on each on pore walls; the Nin site is separated by 3.52 Å along the z direction. d Reconstructed structure of extended and ordered 1D hexagonal nanochannels; only seven channels and 20 layers are shown. Nanochannels are independent and densely aligned across the material.
