Molecular Insertion: A Master Key to Unlock Smart Photoelectric Responses of Covalent Organic Frameworks

Abstract

Covalent organic frameworks (COFs) show potentials in prominent photoelectric responses by judicious structural design. However, from the selections of monomers and condensation reactions to the synthesis procedures, the acquisition of photoelectric COFs has to meet overmuch high conditions, limiting the breakthrough and modulation in photoelectric responses. Herein, the study reports a creative “lock‐key model” based on molecular insertion strategy. A COF with suitable cavity size, TP‐TBDA, is used as the host to load guests. Merely through the volatilization of mixed solution, TP‐TBDA and guests can be spontaneously assembled via non‐covalent interactions (NCIs) to produce molecular‐inserted COFs (MI‐COFs). The NCIs between TP‐TBDA and guests acted as a bridge to facilitate charge transfer in MI‐COFs, unlocking the photoelectric responses of TP‐TBDA. By exploiting the controllability of NCIs, the MI‐COFs can realize the smart modulation of photoelectric responses by simply changing the guest molecule, thus avoiding the arduous selection of monomers and condensation reactions required by conventional COFs. The construction of molecular‐inserted COFs circumvents complicated procedures for achieving performance improvement and modulation, providing a promising direction to construct late‐model photoelectric responsive materials.

Enhanced iodine capture by the hydrogen bond reconstruction strategy

“…10 Nevertheless, the low adsorption capacity, high prices and toxicity of Ag-based materials could not meet the industrial request. 11 Many kinds of absorbents for iodine capture have been studied, including activated carbon, 12–14 bismuth-modified materials, 15–18 covalent organic frameworks (COFs), 19–22 metal–organic frameworks (MOFs), 23–25 nano-porous organic polymers (NOPs), 26 hyper-crosslinked polymer (HCPs), 27–29 and other related materials. However, these materials still have some disadvantages, such as low efficiency, high preparatory costs and a lack of long-term storage ability.…”

Metalated covalent organic frameworks as efficient catalysts for multicomponent tandem reactions

“…28 As crystalline polymer porous materials, COFs have the advantages of low density, high specific surface area, and ease of modification and functionalization. Consequently, they have been extensively investigated and demonstrate promising application prospects in various fields such as gas storage and separation, 29,30 optoelectronics, 31,32 energy storage, 33,34 sensing, 35,36 and catalysis. 37,38 Notably, the unique attributes of COFs have made them exceptional carriers for metal species and function.…”