Extensive Screening of Solvent‐Linked Porous Polymers through Friedel–Crafts Reaction for Gas Adsorption

Abstract

Porous solids with high surface areas, thermal stability, and chemically robust nature have attracted great attention because of their applications in gas capture and storage, [1] water treatment, [2] and catalysis. [3] In addition to the commonly used porous materials in the industry such as zeolites, activated carbons, and molecular sieves, recent developments show that various classes of new porous solids have emerged, such as metal organic frameworks (MOFs), [4] covalent organic frameworks (COFs), [5] covalent organic polymers (COPs), [6] hypercross-linked polymers (HCPs), [3e,7] microporous organic polymers (MOPs), [8] porous aromatic frameworks (PAFs), [9] porous polymer networks (PPNs), [10] and benzimidazole-linked polymers (BILPs). [11] To be used in industrial scale, these materials are expected to be highly porous, thermally and chemically robust, and easily synthesized from inexpensive precursors. Although numerous materials have been reported so far, most have drawbacks such as difficult synthetic procedures, expensive and complex starting monomers, or require rare earth metals. So far, only a handful of these porous materials have proven relatively scalable with affordable synthesis. [12] Considering the availability of the precursors and reagents, Friedel-Crafts (FC) alkylation [13] is one of the most promising

Adjustable Functionalization of Hyper-Cross-Linked Polymers of Intrinsic Microporosity for Enhanced CO2 Adsorption and Selectivity over N2 and CH4

“…In fact, apart from TPB-HC , which seems to exhibit a slightly larger particle size than the other three, all polymers seem to display globular particles of around 1–2 μm in size. All of the other functionalized polymers herein reported followed the same trend indicated by TPB-PIMs , which is also in line with similar published materials, ,, proving the reproducibility of our methods.…”

The mechanochemical synthesis of polymers

“…Conventional Friedel–Crafts alkylation of porous organic polymers usually requires long heating times of up to 36 h, 268 gel formation, 269 or prolonged stirring (up to 48 h) in hazardous solvents such as dichloromethane, chloroform, or 1,2-dichloroethane. 270 These deficiencies can be circumvented using a mechanochemical approach drastically decreasing the synthesis time down to 35 minutes. Despite the similarities between both reactions, the mechanochemical Friedel–Crafts reaction yields porous polymers with higher surface areas than Scholl coupling under similar conditions.…”

Influence of the Intrinsic Nanocore Environment in a Pd-Metalated Porous Organic Polymer for Catalytic Biomass-Derived Furfural Upgrading

“…The appearance of the characteristic resonance signals at ∼129.2 and ∼129.4 ppm corresponds to the unsubstituted aromatic carbons of the (Ph−PPh 3 )−Pd moiety in Pd@KAP-1 and Pd@KAP-2, respectively. 37 In addition, two signature bands centered at 138.2 and 137.2 ppm reveal the C-substituted sp 2 carbon atoms formed during the course of the polymerization with the methylene cross-linking agents. 16 The porosity of the as-synthesized Pd@KAPs was evaluated by an N 2 adsorption−desorption isotherm analysis at 77 K. Pd@KAP-1 exhibited a typical type-IV isotherm with high N 2 uptake at low P/P 0 , followed by gradual uptake with a very broad hysteresis loop at high P/P 0 values (Figure 3a).…”

“…The MAS NMR spectra (Figure a and c) exhibited strong resonance peaks at ∼37.7 and ∼36.7 ppm, which are attributed to the methylene (−CH 2 −) linker. The appearance of the characteristic resonance signals at ∼129.2 and ∼129.4 ppm corresponds to the unsubstituted aromatic carbons of the (Ph–PPh 3 )–Pd moiety in Pd@KAP-1 and Pd@KAP-2, respectively . In addition, two signature bands centered at 138.2 and 137.2 ppm reveal the C-substituted sp 2 carbon atoms formed during the course of the polymerization with the methylene cross-linking agents …”

“…The porosity of the as-synthesized Pd@KAPs was evaluated by an N 2 adsorption–desorption isotherm analysis at 77 K. Pd@KAP-1 exhibited a typical type-IV isotherm with high N 2 uptake at low P / P 0 , followed by gradual uptake with a very broad hysteresis loop at high P / P 0 values (Figure a) . Swelling of the polymeric framework during N 2 gas uptake, which triggers irreversible gas adsorption, could be the main reason for the appearance of the H 3 -type hysteresis loop at high pressures ( P / P 0 > 0.5).…”