Self-sorted pore-formation in the construction of heteropore covalent organic frameworks based on orthogonal reactions.

Two heteropore COFs have been constructed by taking advantage of orthogonal dynamic covalent bonds. And an unprecedented self-sorted pore-formation in the polymerization process was observed, from which micropores with distinctive bonding manners were produced.

Regulating the topology of 2D covalent organic frameworks by the rational introduction of substituents.

The topology of a covalent organic framework (COF) is generally believed to be dictated by the symmetries of the monomers used for the condensation reaction. In this context, the use of monomers with different symmetries is usually required to afford COFs with different topologies. Herein, we report a conceptual strategy to regulate the topology of 2D COFs by introducing alkyl substituents into the skeleton of a parent monomer. The resulting monomers, sharing the same C2 symmetry, were assembled with a D2h symmetric tetraamine to generate a dual-pore COF or single-pore COFs, depending on the sizes of the substituents, which were evidenced using PXRD studies and pore size distribution analyses. These results demonstrate that the substituent is able to exert a significant influence on the topology of COFs, which is crucial for their application.

Two-dimensional dual-pore covalent organic frameworks obtained from the combination of two D2h symmetrical building blocks.

A strategy to construct covalent organic frameworks (COFs) bearing two different kinds of pores has been developed, by which two dual-pore COFs were fabricated through the condensation reactions of two D2h symmetrical building blocks. The COFs exhibit good adsorption capacities for CO2 and H2.

Construction of Covalent Organic Frameworks Bearing Three Different Kinds of Pores through the Heterostructural Mixed Linker Strategy.

It is very important to create novel topologies and improve structural complexity for covalent organic frameworks (COFs) that might lead to unprecedented properties and applications. Despite the progress achieved over the past decade, the structural diversity and complexity of COFs are quite limited. In this Communication, we report the construction of COFs bearing three different kinds of pores through the heterostructural mixed linker strategy involving the condensation of a D2h-symmetric tetraamine and two C2-symmetric dialdehydes of different lengths. The complicated structures of the triple-pore COFs have been confirmed by powder X-ray diffraction and pore size distribution analyses.

The construction of a two-dimensional supramolecular organic framework with parallelogram pores and stepwise fluorescence enhancement.

A novel single-layer two-dimensional (2D) supramolecular organic framework (SOF) with parallelogram pores has been assembled to turn on the fluorescence emission of a non-emissive building block, and the emission could be further enhanced by the aggregation of the as-prepared 2D monolayers.

One-step construction of two different kinds of pores in a 2D covalent organic framework.

Covalent organic frameworks (COFs) are crystalline porous materials bearing microporous or mesoporous pores. The type and size of pores play crucial roles in regulating the properties of COFs. In this work, a novel COF, which bears two different kinds of ordered pores with controllable sizes: one within microporous range (7.1 Å) and the other in mesoporous range (26.9 Å), has been constructed via one-step synthesis. The structure of the dual-pore COF was confirmed by PXRD investigation, nitrogen adsorption-desorption study, and theoretical calculations.