Porous Organic Polymers in Catalysis: Opportunities and Challenges

Kaur, Parminder; Hupp, Joseph T.; Nguyen, SonBinh T.

doi:10.1021/cs200131g

Cited by 856 publications

(513 citation statements)

References 112 publications

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“…They have been used in an increasingly large number of applications, for example, separation and purification, catalysis, drug delivery, solid phase organic synthesis, microencapsulation of phase change materials and templates for nanoparticle growth [4–10]. Such applications, especially as support for catalyst immobilization frequently require large particle size area, which necessitates the formation of pores (of the required dimensions) in the bead structure.…”

Section: Introductionmentioning

confidence: 99%

A novel route for synthesis of cross-linked polystyrene copolymer beads with tunable porosity using guar and xanthan gums from bioresources as alternative synthetic suspension stabilizers

Rahmatpour

Goodarzi

Moazzez

2018

Designed Monomers and Polymers

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Cross-linked polymer beads with different cross-linking agent loading were prepared by carrying out cross-linking suspension copolymerization of styrene-divinylbenzene (St- DVB) monomers using guar gum (GG) and xanthan gum (XG) from bioresources as eco-friendly suspension biopolymer stabilizers in the presence of non reactive diluents. The effects of GG and XG as suspension biostabilizers on the characteristics of the styrene copolymer beads were investigated regarding thermal properties, porosity characteristics, solvent swelling ratio, and surface morphologies using TGA, DSC, XRD, SEM, BET analyses. Spherical and regular beads with smooth surface were produced and the average particle size was in the range 170–290 μm (50–80 mesh size). The porosity characteristics of the produced beads including surface area and pore volume were in range 0.45 m2/g and 32–45 ml/g, respectively. Overall, the present article provided a novel route to prepare cross-linked polystyrene copolymer beads with tunable porosity suitable for catalyst support.

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Section: Introductionmentioning

confidence: 99%

A novel route for synthesis of cross-linked polystyrene copolymer beads with tunable porosity using guar and xanthan gums from bioresources as alternative synthetic suspension stabilizers

Rahmatpour

Goodarzi

Moazzez

2018

Designed Monomers and Polymers

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“…N anoporous polymers [1][2][3][4][5][6] (pore width 1-100 nm) show considerable promise in gas capture 7 , storage 8 and separation technologies 9 , and as nano-filtration membranes 3 , catalysts 10 , drug delivery vehicles 11 and charge carriers 12,13 . These mostly organic polymers can easily be designed and constructed via facile synthetic protocols.…”

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confidence: 99%

Unprecedented high-temperature CO2 selectivity in N2-phobic nanoporous covalent organic polymers

et al. 2013

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Post-combustion CO 2 capture and air separation are integral parts of the energy industry, although the available technologies remain inefficient, resulting in costly energy penalties. Here we report azo-bridged, nitrogen-rich, aromatic, water stable, nanoporous covalent organic polymers, which can be synthesized by catalyst-free direct coupling of aromatic nitro and amine moieties under basic conditions. Unlike other porous materials, azo-covalent organic polymers exhibit an unprecedented increase in CO 2 /N 2 selectivity with increasing temperature, reaching the highest value (288 at 323 K) reported to date. Here we observe that azo groups reject N 2 , thus making the framework N 2 -phobic. Monte Carlo simulations suggest that the origin of the N 2 phobicity of the azo-group is the entropic loss of N 2 gas molecules upon binding, although the adsorption is enthalpically favourable. Any gas separations that require the efficient exclusion of N 2 gas would do well to employ azo units in the sorbent chemistry.

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“…Thermogravimetric analyses (TGA) were carried out in an air atmosphere with a heating rate of 10°C min ¹1 on a STA449C integration thermal analyzer. 1 H NMR experiments were carried out on a MERCURY plus 400 spectrometer operating at resonance frequencies of 400 MHz. Analytical high-performance liquid chromatography (HPLC) was performed on a YL-9100 HPLC with UV detection at 220 nm.…”

Section: Methodsmentioning

confidence: 99%

Chiral Porous TADDOL-Embedded Organic Polymers for Asymmetric Diethylzinc Addition to Aldehydes

Wang

Zhang

Liu

et al. 2014

Bulletin of the Chemical Society of Japan

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Two chiral porous organic polymers (CPOPs) were synthesized by linking a TADDOL-embedded building block with arylethynylenes units. The CPOPs are highly stable to thermal treatment, moisture, acidity, and basicity. The dihydroxy groups of TADDOL inside the pores promise the CPOPs as good asymmetric catalysts after postsynthesis modification with a secondary metal center. After being treated with Ti(O i Pr) 4 , the CPOPs could be used as highly effective and reusable heterogeneous catalyst for asymmetric diethylzinc addition to aldehydes with up to 99% conversion and 95% ee. This work promises the potential of generating chiral solid catalysts with unique and practically useful enantioselective functions via a modular approach.As one of the most important porous materials, porous organic polymers (POPs) have attracted considerable attention during the past decades, owing to their wide range of potential applications in heterogeneous catalysis, 15 gas adsorption 610 and molecular separations. 1114 In comparison with metalorganic frameworks (MOFs) 1518 and crystalline covalent-organic frameworks (COFs), 1922 these amorphous porous materials show high stability to thermal treatment, moisture, and acidity/ basicity conditions, thus presenting an excellent platform for engineering recyclable and reusable heterogeneous catalysts. POPs can also be constructed from catalytic active molecular building blocks and then employed for chemical catalysis with high activity, whose catalytic performance can be rationally tuned by adjusting the monomeric units. 2325 While an appreciable amount of work has been carried out on the use of POPs in gas storage and separations, only a small number of reports have explored their use in catalysis, especially in asymmetric catalysis, 2630 mainly because of the difficulty in their controllable synthesis and intricate behaviors in catalysis progress.TADDOL (α,α,α¤,α¤-tetraaryl-1,3-dioxolane-4,5-dimethanol) derivatives with intrinsic C 2 symmetry have been established as one of the best known privileged ligands in the field of asymmetric synthesis.3135 Heterogeneous TADDOL catalysts can be prepared by immobilizing TADDOL to resins, 33 highly porous silica gel, 34 or by copolymerizing TADDOL derivatives with styrene, 35 but only a few of them exhibit satisfactory enantioselectivity. Asymmetric diethylzinc addition to aldehydes is important for preparing chiral alcohols. 3638 In this work, we describe the synthesis of two chiral porous organic polymers (CPOPs) from a TADDOL based building unit and demonstrate their heterogeneous catalytic activities in asymmetric diethylzinc addition to aldehydes after post-modified with Ti(O i Pr) 4 , with up to 95% ee. Results and DiscussionTADDOL tetrabromo starting material A (4R,5R)-2,2-dimethyl-α,α,α¤,α¤-tetra-P-bromophenyl-1,3-dioxolane-4,5-dimethanol was prepared in two steps from readily available L-tartaric acid in moderate overall yield (39%). As shown in Scheme 1, chiral porous organic polymers (CPOPs 1 and 2) were synthesized in good yields (9...

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Porous Organic Polymers in Catalysis: Opportunities and Challenges

Cited by 856 publications

References 112 publications

A novel route for synthesis of cross-linked polystyrene copolymer beads with tunable porosity using guar and xanthan gums from bioresources as alternative synthetic suspension stabilizers

A novel route for synthesis of cross-linked polystyrene copolymer beads with tunable porosity using guar and xanthan gums from bioresources as alternative synthetic suspension stabilizers

Unprecedented high-temperature CO2 selectivity in N2-phobic nanoporous covalent organic polymers

Chiral Porous TADDOL-Embedded Organic Polymers for Asymmetric Diethylzinc Addition to Aldehydes

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