Amine‐Tagged Fragmented Ligand Installation for Covalent Modification of MOF‐74

Abstract

MOF‐74 is one of the most explored metal–organic frameworks (MOFs), but its functionalization is limited to the dative post‐synthetic modification (PSM) of the monodentate solvent site. Owing to the nature of the organic ligand and framework structure of MOF‐74, the covalent PSM of MOF‐74 is very demanding. Herein, we report, for the first time, the covalent PSM of amine‐tagged defective Ni‐MOF‐74, which is prepared by de novo solvothermal synthesis by using aminosalicylic acid as a functionalized fragmented organic ligand. The covalent PSM of the amino group generates metal binding sites, and subsequent post‐synthetic metalation with PdII ions affords the PdII‐incorporated Ni‐MOF‐74 catalyst. This catalyst exhibits highly efficient, size‐selective, and recyclable catalytic activity for the Suzuki–Miyaura cross‐coupling reaction. This strategy is also useful for the covalent modification of amine‐tagged defective Ni2(DOBPDC), an expanded analogue of MOF‐74.

Output Enhancement of Triboelectric Nanogenerators Based on Hierarchically Regular Cadmium Coordination Polymers for Photocycloaddition

“…Coordination polymers (CPs) fabricated by various metal ions/clusters and diverse organic linkers through coordination-driven self-assembly have been extensively developed by utilizing the principles of reticular chemistry based on well-defined organic building blocks. − To realize the desired functional performance of CPs, significant efforts have been devoted toward the controlled design and development of CPs with hierarchical structures, which could serve as a new generation of molecular devices. ,− The key necessity for the desired hierarchical frameworks of CPs is to precisely control the size and shape of bridging ligands as building blocks, which have high shape homogeneity and narrow size distribution. ,,,− The incorporation of suitable building blocks in CPs through direct synthetic or postsynthetic modification pathways could not only engender a particular hierarchical structure with the relative positioning of the coordinating groups as well as the electronic features but also generate electrically conducting means for assessing the electronic gain/loss ability of CPs by density functional theory (DFT) and experiments. ,− …”

Palladium‐Based Metal Organic Frameworks as Heterogeneous Catalysts for C−C Couplings

“…The introduction of amino salicyl‐like fragmented linker (defect engineering approach) in the framework of Ni‐MOF‐74 was achieved via coordination of the −COOH and −OH groups to the Ni‐oxo clusters for further PSM with pyridine carboxaldehyde generating the Schiff base ready to coordinate Pd active sites (Figure 7). [83] The crystalline structure was preserved during the whole PSM process, and the pore size distribution suggests a modification of the pores around the defective positions involving the Schiff‐base linker, which reduced the pore size after the Pd metalation. The incorporated Pd(II) sites were catalytically active (1.3 mol% Pd) in the Suzuki‐Miyaura coupling between bromobenzene and phenylboronic acid at 100 °C in toluene using K 2 CO 3 as a base for 24 h. The observed yield of 99 % was (TON: 76) superior compared to PdCl 2 (60 %, TON: 46) and the activity of the MOF maintained over five reaction cycles (as well as the MOF crystallinity), with no appreciable leaching in the hot filtration test.…”

Selective Detection of Nucleotides in Infant Formula Using an N-Rich Covalent Triazine Porous Polymer

“…The unique properties of covalent organic frameworks (COF), including their high surface area, physicochemical stability and structural diversity, have led to their receiving extensive attention during the past few years [3][4][5][6][7][8][9][10]. However, the adsorption by traditional COFs mainly depends on their large conjugated systems, porous structure and hydrophobicity, and this restricts their use with polar or ionic solutes [11,12].…”