Pore engineering of metal-organic frameworks with coordinating functionalities

Abstract

Among porous materials, metal-organic frameworks (MOFs) take the lead in heterogeneous support catalysts because the structure of MOFs can be readily tuned by choice of metal and organic building blocks, and further be modified with diverse functional groups. In order to immobilize catalytically active metal sites on MOFs and efficiently utilize them, it would be essential to employ the coordinating functionalities to the pores and frameworks, which can anchor the metal sites with high stability and control the reactivity of the catalytic centres. However, in order not to obtain the unwanted structures by participation of additional coordinating groups in the framework construction of MOFs, the pore engineering with coordinating functionalities should be carefully implemented. In this review, we discuss various strategies of pore engineering to impart catalytic activities to the MOF architectures, classifying them into two approaches: pre-integrated ligand and sequential attachment. The former demonstrates the use of organic ligands that are already capable of possessing catalytic sites, and the ligands can directly integrate the metals before or after the production of the MOFs. The other approach is the post-synthetic attachment of coordinating functionalities through the sequential attachment process, in which immobilization of catalytically active metal sites also can be achieved by both pre-and post-metalation. Finally, this review will comprehensively discuss the representative catalytic reactions of MOF-based heterogeneous catalysts.

Porphyrin-Containing MOFs and COFs as Heterogeneous Photosensitizers for Singlet Oxygen-Based Antimicrobial Nanodevices

“…Examples of 3D MOFs issued from a solvothermal reaction between TCPP and a zirconium salt, often ZrOCl 2 or ZrCl 4 , may lead to different structures where the resulting zirconium cluster has the general formula Zr 6 (μ 3 -O) 4 (μ 3 –OH) 4 (OH) 12– n (H 2 O) 12– n (COO) n ( n = 6 (PCN-224), 8 (PCN-222), and 12 (PCN-223; Figure ). An example of a 2D MOF is provided in Figure . Construction of composites comprising of, for instance, gold nanorods, polydopamine nanoparticles (NPs), and polydopamine/platinum nanoparticles inside the pores of the MOFs or deposited onto graphene oxide does not preclude the photosensitization of O 2 ( 1 Δ g ) .…”

A Comprehensive Review on the Use of Metal–Organic Frameworks (MOFs) Coupled with Enzymes as Biosensors

“…As shown in Figure 2, the reversible, flexible, tunable, and responsive mechanisms of MOFs correspond to 'breathing' movements, when their structures expand and contract, and also deforming in the process. 'Swelling' happens when the monomer increases in size to accommodate the molecule within its space, without changing its shape; finally, a 'linker rotation' occurs when linkers change their angle while making a rotation movement without breaking their bonds, also to accommodate molecules [24,[65][66][67][68].…”

Strategies in Metal–Organic Framework‐based Catalysts for the Aerobic Oxidation of Alcohols and Recent Progress

“…The introduction of metal ions through chelating ligands is a key strategy for preparing MOF catalysts. 39 Various metal cations such as Pd(II), Ir(III), Ru(II), and Rh(III) have been installed in MOF pores through chelation by 2,2 0 -bipyridyl and imines. Among them, redox-active copper and europium have been studied for aerobic oxidation after incorporation in MOFs.…”