Palladium Nanoparticles Supported on a Porous Organic Polymer: An Efficient Catalyst for Suzuki‐Miyaura and Sonogashira Coupling Reactions

A new porous organic polymer (POP) with high thermal stability and large surface area has been synthesized and applied in the preparation of Pd/POP catalyst. Pd/POP was characterized by XRD, TGA, SEM and TEM. The catalyst consists of highly dispersed palladium nanoparticles of 0.9–4 nm size on POP with a large surface area of 650 m²/g. It presents high catalytic activity for Suzuki‐Miyaura and Sonogashira reactions. The catalyst was reusable for three to five times without significant loss of activity.     

Palladium Supported on Porous Organic Polymer as Heterogeneous and Recyclable Catalyst for Cross Coupling Reaction

Palladium immobilized on an amide and ether functionalized porous organic polymer (Pd@AEPOP) is reported to be an effective heterogeneous catalyst for the Heck cross-coupling reaction of aryl iodides with styrene for the synthesis of diphenylethene derivatives. Excellent yields can be obtained using a 0.8 mol% Pd catalyst loading under the optimized reaction condition. The heterogeneous Pd@AEPOP catalyst can also be applied on the Suzuki reaction and the reduction of nitroarene.     

Prefunctionalized Porous Organic Polymers: Effective Supports of Surface Palladium Nanoparticles for the Enhancement of Catalytic Performances in Dehalogenation

Three porous organic polymers (POPs) containing H, COOMe, and COO^? groups at 2,6‐bis(1,2,3‐triazol‐4‐yl)pyridyl (BTP) units (i.e., POP‐1, POP‐2, and POP‐3, respectively) were prepared for the immobilization of metal nanoparticles (NPs). The ultrafine palladium NPs are uniformly encapsulated in the interior pores of POP‐1, whereas uniform‐ and dual‐distributed palladium NPs are located on the external surface of POP‐2 and POP‐3, respectively. The presence of carboxylate groups not only endows POP‐3 an outstanding dispersibility in H₂O/EtOH, but also enables the palladium NPs at the surface to show the highest catalytic activity, stability, and recyclability in dehalogenation reactions of chlorobenzene at 25 °C. The palladium NPs on the external surface are effectively stabilized by the functionalized POPs containing BTP units and carboxylate groups, which provides a new insight for highly efficient catalytic systems based on surface metal NPs of porous materials.     

A Porous Organic Poly(triphenylimidazole) Decorated with Palladium Nanoparticles for the Cyanation of Aryl Iodides

A new porous organic poly(triphenylimidazole), PTPI‐Me, was prepared through a Yamamoto self‐coupling reaction of 2,4,5‐tris‐(4‐bromophenyl)‐1‐methyl‐1H‐imidazole (TPI‐Me) in the presence of bis(1,5‐cyclooctadiene)nickel(0). The polymer was subsequently decorated with Pd nanoparticles (NPs) to afford a heterogeneous cyanation catalyst, Pd@PTPI‐Me. Pd NPs with an average diameter of 2.7 nm were grown within the PTPI‐Me framework, owing to the coordination of the imidazole rings to the Pd species. The resultant Pd@PTPI‐Me catalyst, with a Pd loading of 0.13 mmol g^?1, exhibited superior catalytic activity for the cyanation of aryl iodides. More importantly, the heterogeneous catalyst was also readily recycled and displayed negligible deactivation after five cycles.     

Advances in Porous Organic Polymers for Efficient Water Capture

Desiccant driven dehumidification for maintaining the proper humidity levels and atmospheric water capture with minimum energy penalty are important aspects in heat pumps, refrigeration, gas and liquid purifications, gas sensing, and clean water production for improved human health and comfort. Water adsorption by using nanoporous materials has emerged as a viable alternative to energy-intensive industrial processes, thus understanding the significance of their porosity, high surface areas, vast pore volumes, chemical and structural features relative to the water adsorption is quite important. In this review article, important features of nanoporous materials are presented, including zeolites, porous carbons, as well as crystalline and amorphous porous organic polymers (POPs) to define the interactions between the water molecules and the polar/non-polar functional groups on the surface of these nanoporous materials. In particular, focus is placed on the recent developments in POPs in the context of water capture as a result of their remarkable stability towards water and wide range of available synthetic routes and building blocks for their synthesis. We also highlighted recent approaches to increase the water sorption capacity of POPs by modifying their structure, morphology, porosity, and chemical functionality while emphasizing their promising future in this emerging area.     

A Pyridinium-Pyridinium Zinc(II) Porphyrin Ion Porous Organic Polymer as Efficient Heterogeneous Catalyst for Cycloaddition of Epoxides with CO2

A zinc(II)porphyrin-based ion porous organic polymer (ZnTPyPBr₄-iPOP) is successfully synthesized from newly designed pyridinium-functionalized cationic Zn-porphyrin monomer (ZnTPyPBr₄) by free radical self-polymerization, and is employed as an efficient bifunctional heterogeneous catalyst for CO₂ cycloaddition reaction with epoxides. The ZnTPyPBr₄-iPOP exhibits excellent catalytic performance and good substrate expansion in CO₂ cycloaddition reaction under solvent-free and cocatalyst-free conditions with a TOF as high as 15,500 h⁻¹ for the cycloaddition of CO₂ and epichlorohydrin. The synergistic effect of zinc(II)porphyrin as the Lewis acidic site and the Br⁻ anion as the nucleophile in ZnTPyPBr₄-iPOP responds to the high catalytic activity. Moreover, ZnTPyPBr₄-iPOP can easily be recovered and reused at least seven times without the loss of activity. This work provides a valuable approach for the synthesis of novel and efficient heterogeneous catalyst for CO₂ cycloaddition.     

Chemistry in Confinement: Copper and Palladium Catalyzed Ecofriendly Organic Transformations within Porous Frameworks

A concise account on the use of transition metals copper (Cu) and palladium (Pd), as their cations as well as nanoparticles exchanged/immobilized onto porous frameworks such as zeolites, metal organic frameworks (MOFs), covalent organic polymers (COPs) and hollow nanostructures, functioning as catalysts in organic synthesis is presented. This biomimetic account, “focusing on catalytic systems in confinement” within zero‐dimensional microenvironments and second sphere coordination covers primarily results from our group on N‐sulfonylketenimine mediated cycloaddition, hydrogenation and C−C bond forming reactions, thus providing an interesting insight into the versatility and utility of these Cu and Pd catalysts. Other significant advantages and green credentials of confinement such as stability, selectivity, reusability, promotion of multicomponent reactions, use of green solvents, atom economy, and use of ambient conditions are highlighted at appropriate places. In the final section, our views on the current achievements and the future prospects in this area are summarized.     

Amorphous Porous Organic Polymers Based on Schiff‐Base Chemistry for Highly Efficient Iodine Capture

Porous organic polymers (POPs) have been considered as prominent adsorbents for volatile iodine. So far, both crystalline and amorphous POPs have accomplished excellent iodine capture capability. Considering the difficulty and challenges in preparing perfect crystalline POPs, more explorations into developing versatile amorphous POPs are needed. Herein, amorphous POPs based on the Schiff‐base reaction were designed and synthesized for volatile iodine removal. Four amorphous POPs products named as NDB‐H , NDB‐S , ADB‐HS , and ADB‐S obtained under different solvothermal conditions were investigated in terms of their morphologies, porosity, and their iodine enrichment performance in detail. It is noteworthy that excellent efficiency for removing iodine vapor was acquired for NDB‐S (≈425 wt %), ADB‐HS (≈345 wt %), and ADB‐S (≈342 wt %). Remarkably, NDB‐H exhibited an iodine capture capacity up to ≈443 wt %. Excellent reusability was obtained as well. Amorphous NDB‐H has accomplished an extremely high iodine capture performance, illustrating the great chance to exploit versatile amorphous POPs for iodine enrichment and removal based on Schiff‐base chemistry.     

Pyrene-Based Fluorescent Porous Organic Polymers for Recognition and Detection of Pesticides

Eating vegetables with pesticide residues over a long period of time causes serious adverse effects on the human body, such as acute poisoning, chronic poisoning, and endocrine system interference. To achieve the goal of a healthy society, it is an urgent issue to find a simple and effective method to detect organic pesticides. In this work, two fluorescent porous organic polymers, LNU-45 and LNU-47 (abbreviation for Liaoning University), were prepared using π-conjugated dibromopyrene monomer and boronic acid compounds as building units through a Suzuki coupling reaction. Due to the large π-electron delocalization effect, the resulting polymers revealed enhanced fluorescence performance. Significantly, in sharp contrast with the planar π-conjugated polymer framework (LNU-47), the distorted conjugated structure (LNU-45) shows a higher specific surface area and provides a broad interface for analyte interaction, which is helpful to achieve rapid response and detection sensitivity. LNU-45 exhibits strong fluorescence emission at 469 nm after excitation at 365 nm in THF solution, providing strong evidence for its suitability as a luminescent chemosensor for organic pesticides. The fluorescence quenching coefficients of LNU-45 for trifluralin and dicloran were 5710 and 12,000 (LNU-47 sample by ca. 1.98 and 3.38 times), respectively. Therefore, LNU-45 serves as an effective “real-time” sensor for the detection of trifluralin and dicloran with high sensitivity and selectivity.     

A Three-Dimensional Porous Organic Semiconductor Based on Fully sp2-Hybridized Graphitic Polymer

Dimensionality plays an important role in the charge transport properties of organic semiconductors. Although three-dimensional semiconductors, such as Si, are common in inorganic materials, imparting electrical conductivity to covalent three-dimensional organic polymers is challenging. Now, the synthesis of a three-dimensional π-conjugated porous organic polymer (3D p-POP) using catalyst-free Diels–Alder cycloaddition polymerization followed by acid-promoted aromatization is presented. With a surface area of 801 m² g⁻¹, full conjugation throughout the carbon backbone, and an electrical conductivity of 6(2)×10⁻⁴ S cm⁻¹ upon treatment with I₂ vapor, the 3D p-POP is the first member of a new class of permanently porous 3D organic semiconductors.     

Synthesis of a Triazaisotruxene-Based Porous Organic Polymer and Its Application in Iodine Capture

A new triazaisotruxene-based porous organic polymer (POP) was designed and successfully synthesized by a FeCl₃-promoted crosslinking reaction. As a result of its porosity and good thermal stability, the designed POP can be utilized as a promising adsorbent for iodine, not only in the gaseous phase, but also in organic and aqueous solutions. Compared to its triazatruxene (TN) analogue, the ITN-based POP shows equal iodine uptake in the gaseous phase and in hexane solution, and better uptake in aqueous solution.     

A Facile and Highly Efficient Approach to Obtain a Fluorescent Chromogenic Porous Organic Polymer for Lymphatic Targeting Imaging

Porous organic polymers have an open architecture, excellent stability, and tunable structural components, revealing great application potential in the field of fluorescence imaging, but this part of the research is still in its infancy. In this study, we aimed to tailor the physical and chemical characteristics of indocyanine green using sulfonic acid groups and conjugated fragments, and prepared amino-grafted porous polymers. The resulting material had excellent solvent and thermal stability, and possessed a relatively large pore structure with a size of 3.4 nm. Based on the synergistic effect of electrostatic bonding and π–π interactions, the fluorescent chromogenic agent, indocyanine green, was tightly incorporated into the pore cavity of POP solids through a one-step immersion method. Accordingly, the fluorescent chromogenic POP demonstrated excellent imaging capabilities in biological experiments. This preparation of fluorescent chromogenic porous organic polymer illustrates a promising application of POP-based solids in both fluorescence imaging and biomedicine applications.     

多孔有机聚合物吸附分离水体系中有机污染物研究和应用进展

有机物对水体的污染严重威胁生态环境安全和人类健康。 如何有效控制和消除水体系中的有机污染物是当前全球性热点问题之一,基于多孔材料的高效吸附是处理水体有机污染的有效方法。 多孔有机聚合物(Porous Organic Polymers,POPs)具有比表面积高、物理化学稳定性好、易修饰等特点,作为新型吸附剂在处理水体系有机污染方面具有广阔的应用前景。 本文综述了近10年来新型多孔有机聚合物对水体系中有机溶剂、农药与杀虫剂、有机染料等污染物的吸附分离研究进展。     

MnFe2O4 Nanocrystals Wrapped in a Porous Organic Polymer: A Designed Architecture for Water‐Splitting Photocatalysis

A novel MnFe₂O₄–porous organic polymer (POP) nanocomposite was synthesized by a facile hydrothermal method and using the highly cross‐linked N‐rich benzene–benzylamine POP. The nanocomposite presented highly efficient photocatalytic performance in the hydrogen evolution reaction (HER) from pure water without addition of any sacrificial agent under one AM 1.5 G sunlight illumination. A photocatalytic activity of 6.12 mmol h^?1 g^?1 was achieved in the absence of any noble metal cocatalyst, which is the highest H₂ production rate reported for nonprecious metal catalysts. The photocatalytic performance of MnFe₂O₄‐POP could be attributed to the intrinsic synergistic effects of manganese ferrite (MnFe₂O₄) nanoclusters interacting with the nitrogen dopant POP with a unique mesoporous nanoarchitecture and spatially confined growth of MnFe₂O₄ in the interconnected POP network, leading to high visible‐light absorption with fast electron transport.     

Eutectic Molten Salt Synthesis of Highly Microporous Macrocyclic Porous Organic Polymers for CO2 Capture

The development of porous materials is of great interest for the capture of CO₂ from various emission sources, which is essential to mitigate its detrimental environmental impact. In this direction, porous organic polymers (POPs) have emerged as prime candidates owing to their structural tunability, physiochemical stability and high surface areas. In an effort to transfer an intrinsic property of a cyclotetrabenzoin-derived macrocycle – its high CO₂ affinity – into porous networks, herein we report the synthesis of three-dimensional (3D) macrocycle-based POPs through the polycondensation of an octaketone macrocycle with phenazine-2,3,7,8-tetraamine hydrochloride. This polycondensation was performed under ionothermal conditions, using a eutectic salt mixture in the temperature range of 200 to 300 °C. The resulting polymers, named 3D-mmPOPs, showed reaction temperature-dependent surface areas and gas uptake properties. 3D-mmPOP-250 synthesized at 250 °C exhibited a surface area of 752 m² g⁻¹ and high microporosity originating from the macrocyclic units, thus resulting in an excellent CO₂ binding enthalpy of 40.6 kJ mol⁻¹ and CO₂ uptake capacity of 3.51 mmol g⁻¹ at 273 K, 1.1 bar.     

Porous Organic Polymer Films with Tunable Work Functions and Selective Hole and Electron Flows for Energy Conversions

Organic optoelectronics are promising technologies for energy conversion. However, the electrode interlayer, a key material between active layers and conducting electrodes that controls the transport of charge carriers in and out of devices, is still a chemical challenge. Herein, we report a class of porous organic polymers with tunable work function as hole‐ and electron‐selective electrode interlayers. The network with organoborane and carbazole units exhibits extremely low work‐function‐selective electron flow; while upon ionic ligation and electro‐oxidation, the network significantly increases the work function and turns into hole conduction. We demonstrate their outstanding functions as anode and cathode interlayers in energy‐converting solar cells and light‐emitting diodes.     

Monolithic Porous Organic Polymer-Photocatalyst Composites for Applications in Catalysis

This Review provides a perspective on porous organic polymer-photocatalyst composites obtained by coupling semiconductors and hydrophilic/hydrophobic polymers which do not modify the properties of the embedded photocatalysts, but can influence the efficiency of the overall catalytic process. Particular attention has been given to polymer composites in the form of monolithic hydrogel/sponge/aerogels obtained by dissolving the polymer in a solvent, which contains the photocatalyst dispersed, inducing gelation or solidification of the solution and subsequently removing the solvent by a drying process. The photocatalytic applications discussed here cover H₂ evolution from water splitting, CO₂ reduction, and organic synthesis. Indeed, the main aim of this Review is to outline an alternative perspective to the highly studied environmental photocatalytic applications, highlighting the photoactive properties of these composites thanks to the incorporation of semiconductors in the 3D porous structure of organic polymers. Finally the challenges and potential advances associated with the use of porous organic polymer-photocatalyst composites for future scientific research are outlined.     

共价有机多孔聚合物合成新策略

共价有机多孔聚合物(COPs)是由有机结构单元通过共价键连接而形成的一类具有微孔或者介孔结构的新型高分子多孔材料, 在能源、物质吸附与分离、气体存储、光电器件、多相催化以及化学/生物传感等方面展现出巨大的应用潜能. 尽管其合成方法众多, 合成单体多样, 产物结构稳定, 但是传统方法合成的有机多孔材料大多是无定型的, 结构难以控制, 且通常不溶不熔, 很难再加工. 为了解决这些问题, 近年来很多新的合成方法和合成策略被开发出来, 为共价有机多孔聚合物的进一步发展指明了方向. 本文将对这些最新的研究进展做一简要的介绍.     

Porous Organic Polymers Containing a Sulfur Skeleton for Visible Light Degradation of Organic Dyes

Three novel chemically stable porous organic polymers (POPs) were synthesized by the hydrothermal method; the POPs contain sulfone bonds (TpSD), no sulfur atoms (TpMD), or thioether bonds (TpTD). The catalytic mechanism of the POP with sulfone bonds was studied, and it was found that the wide visible light absorption range, high specific surface area, and the hydrophilicity of the material significantly promoted the catalytic efficiency of TpSD. The presence of O=S=O gives TpSD a higher degree of conjugation than TpMD and TpTD, so TpSD shows the strongest UV/Visible absorption and faster transmission of electrons. The photocatalytic degradation of Rhodamine B (RhB) molecules is approximately 100 % with TpSD and its pseudo‐first‐order rate constant is 0.0770 min^?1, which is the highest among all reported non‐metallic photocatalysts. Moreover, it is also the first time that sulfur‐containing polymer have been used in photocatalytic degradation of dyes.