Pillar[5]arene-Integrated Three-Dimensional Framework Polymers for Macrocycle-Induced Size-Selective Catalysis

Abstract

Size-selective catalysis is of key importance in the conversion of crude oil or biomass. Here, we fabricate three pillar[5]arene-integrated porous organic polymers with three-dimensional (3D) network structures using 3D cross-linkers. The resulting polymers possess a high surface-to-mass ratio and exhibit exceptional size-selective catalysis in Knoevenagel condensation reactions. In addition, a mechanistic study indicates that the size-selective catalysis is due to the host−guest interaction between pillar[5]arene and substrates. This study suggests that macrocycle-containing polymers could be a promising candidate for sizeselective catalysis.

Carboxylated Pillar[6]arene Emulates Pillar[5]arene in the Host–Guest Crystal Complexes and Shows Conformational Flexibility in the Solution/Gas Phase

“…Macrocyclic host molecules operating in aqueous media are particularly attractive due to the versatility of their applications in drug delivery, bioimaging, sensing, and self-sorting and as building blocks to create new materials . Carboxylated pillar­[ n ]­arenes entered the large library of water-soluble macrocyclic hosts more than a decade ago, immediately attracting a lot of attention. , These water-soluble pillar­[ n ]­arenes appear to be relatively nontoxic, with potential application in drug delivery, , sensing, supramolecular catalysis, , porous materials, , etc . They resemble more mature calix­[ n ]­arenes in terms of chemical structure and electron-rich cavities and also show some similarity to cucurbit­[ n ]­urils when considering their columnar shape with two equivalent entrances to the cavity.…”

Covalently bridged pillararene-based polymers: structures, synthesis, and applications

“…86 Recently, CP-7 was reported by Ma's group with P13 and tris(4aminophenyl)amine for the exceptional size-selective catalysis. 87 Yang's team constructed CP-8 by employing diacylhydrazinefunctionalized pillar [5]arene P11 and tris(4-formylbiphenyl)amine, where the building blocks were held together by hydrazone bonds. 88 In this work, CP-8 possesses the property of brilliant yellow-green luminescence and unique solvatochromism behaviors because the solvent made a significant effect on its conformation.…”

“…90 Later, Lan and colleagues prepared CP-12 and CP-13 simultaneously via the polycondensation between P13 and two linkers ((tetrakis(4-aminophenyl) methane and tetrakis(4-aminophenyl)-1,4-benzenediamine)) respectively for size-selective catalysis. 87 In 2018, Yang's group reported CP-14 by electrophilic aromatic substitution of dibenzaldehyde-functionalized pillar [5]arene P13 and pyrrole for heterogeneous catalysis, where the heteroatom-doped porphyrins possess powerful coordination ability. 91 Similarly, CP-15 was constructed based on the covalent co-assembly of 1,4bis(bromoethyloxy)copillar [5]arene P10 and 5,10,15,20-tetra(4pyridyl)porphyrin-Zn(ii) via electrophilic substitution reaction.…”

MOFganic Chemistry: Challenges and Opportunities for Metal-Organic Frameworks in Synthetic Organic Chemistry

“…79 As such, MOFs greatly expand the toolbox available for size-selective catalysis. [80][81][82][83][84][85] The examples reviewed herein highlight the capability of MOFs to access unique reactivity and selectivity modes that are unattainable via traditional homogeneous catalysis.…”