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Summary of the polymerization reactions templated by MOFs. The types of the polymerization reactions are classified by the reaction mechanism.
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Polymers have become one of the major types of materials that are essential in our daily life. The controlled synthesis of value-added polymers with unique mechanical and chemical properties have attracted broad research interest. Metal–organic framework (MOF) is a class of porous material with immense structural diversity which offers unique advan...
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The library of isostructural porous frameworks enables a systematic survey to optimize the structure and functionality of porous materials. In contrary to metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), a handful of isostructural frameworks have been reported for hydrogen-bonded organic frameworks (HOFs) due to the weakness...
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... Therefore, the search for green and efficient new energy sources has become a hot topic of research for scientists worldwide. Just as plants can convert CO 2 in the atmosphere into organic compounds such as oxygen and sugar through photosynthesis [9][10][11][12][13], if humans can efficiently use CO 2 in the air to produce small organic molecules of high energy density such as carbon monoxide, formic acid, methanol, and methane, they can both effectively reduce the accumulated CO 2 in the atmosphere and the greenhouse effect, and also produce fuel and more fine chemical products, alleviating mankind's heavy reliance on fossil fuels [14][15][16][17]. ...
With the rapid development of modern society, environmental problems, including excessive amounts of CO2 released in the atmosphere, are becoming more and more serious. It is necessary to develop new materials and technologies to reduce pollution. Among them, metal–organic frameworks (MOFs) have shown potential for application in the area of catalysis due to their ultra-high specific surface area, structural versatility, and designability as well as ease of modification and post-synthesis. Herein, we summarize recent research advances by use of MOFs for boosting CO2 conversion. Furthermore, challenges and possible research directions related to further exploration are also discussed.
... Zeolitic imidazolate frameworks (ZIFs) are a subclass of nanoporous metal organic frameworks (MOFs) composed of organic linkers coordinated to metal ions [1,2]. Their huge pore volume, surface area, and broad range of accessible pore sizes [3] make them very desirable for applications such as adsorption [4,5], catalysis [6][7][8], and membranes [9,10]. In particular, due to its simple synthesis procedure and excellent chemical and thermal stability [11], ZIF-8 is a desirable membrane material [12,13]. ...
The separation of C3 olefin and paraffin, which is essential for the production of propylene, can be facilitated by the ZIF-8 membrane. However, the commercial application of the membrane has not yet been achieved because the fabrication process does not meet industrial regulatory criteria. In this work, we provide a straightforward and cost-effective membrane fabrication technique that permits the rapid synthesis of ZIF-8 hollow fiber membranes. The scalability of the technology was confirmed by the incorporation of three ZIF-8 hollow fiber membranes into a single module using an introduced fiber mounting methodology. The molecular sieving characteristics of the ZIF-8 membrane module on a binary combination of C3 olefin and paraffin (C3H6/C3H8 selectivity of 110 and a C3H6 permeance of 13 GPU) were examined at atmospheric conditions. In addition, the high-pressure performance of these membranes was demonstrated at a 5 bar of equimolar binary feed pressure with a C3H6/C3H8 selectivity of 55 and a C3H6 permeance of 9 GPU due to propylene adsorption site saturation. To further accurately portray the separation performance of the membrane on an actual industrial feed, the effect of impurities (ethylene, ethane, butylene, i-butane, and n-butane), which can be found in C3 splitters, was investigated and a considerable decrement (~15%) in the propylene permeance upon an interaction with C4 hydrocarbons was confirmed. Finally, the long-term stability of the ZIF-8 membrane was confirmed by continuous operation for almost a month without any loss of its initial performance (C3H6/C3H8 separation factor of 110 and a C3H6 permeance of 13 GPU). From an industrial point of view, this straightforward technique could offer a number of merits such as a short synthesis time, minimal chemical requirements, and excellent reproductivity.
... Metal-organic frameworks (MOFs) are a highly tunable class of porous materials, comprised of inorganic nodes (metal ions, clusters, etc.) and multi-topic organic linkers (carboxylates, phosphonates, pyridines, etc.). 10 Due to the modularity of their structures and functions, [11][12][13][14][15][16] MOFs have proven useful for a wide suite of potential applications 17 including gas separations and storage, [18][19][20] chemical sensing, 21,22 water purification, 23,24 and catalysis. [25][26][27][28][29][30] Among these applications, catalysis has largely capitalized upon the tailorable nature of MOFs to enhance activity and selectivity across various transformations. [31][32][33][34][35][36][37][38] Notably, MOFs are crystalline and thus can be characterized via single crystal X-ray diffraction (SC-XRD), even after post-synthetic modification. ...
Crystallographic characterization of a heterogeneous ethylene polymerization catalyst elucidates a chromium–carbon bond after alkyl aluminum activation and provides mechanistic insights.
The presence of shape‐ and size‐selective catalysts in various catalytic reactions is of paramount importance. Metal‐organic frameworks (MOFs) possess a distinctive characteristic of lacking in‐accessible dead spaces, owing to their well‐structured nature. The effective separation of active sites within MOFs is facilitated by their exceptionally high surface area, which allows for a high density of active sites per unit volume of the catalyst. In this comprehensive review article, we delve into one of the most critical and practical features of MOFs: their ability to modify and engineer the structure of these materials. This structural engineering approach enables the attainment of desired physical, chemical, and surface properties, particularly in the realm of heterogeneous catalysts. The article encompasses several key areas, including surface functionalization within MOFs, synthesis of novel enzyme‐inspired MOFs, creation of mesoporous MOFs, development of porous structures utilizing MOFs, and engineering of structural limitations in MOFs. These rapidly advancing and highly applicable topics, especially in the field of heterogeneous catalysts, are thoroughly investigated and analyzed within the purview of this comprehensive review article.
In this study, we report the successful synthesis of a novel Al-based
MOF/polybenzoxazine nanocomposite by a facile and green approach via thermally
induced ring-opening polymerization (ROP). Structural and thermal characterization
of the synthesized nanocomposite was accomplished using FTIR, XRD, BET and
TGA, and DSC techniques, respectively. The Al-MOF showed catalytic activity in
ROP and good thermal stability compared to the non-catalyzed system. The catalytic
impact of MIL-53-Al on the ROP of benzoxazine is revealed by calorimetry at both
isothermal and dynamic modes in detail. The Starink isoconversional analysis
revealed that the MOF-catalyzed ROP proceeded faster at the reaction’s early stages,
typically at α ≤ 40%. The Friedman method was also applied to the experimental
data to get more insights into the mechanisms of the ROP reaction. Results indicated
that both systems follow a conversion-dependent mechanism for cationic ROP of the
benzoxazine. Although the complexity of the ROP of benzoxazines reduces the
reliability of model fitting, the activation energy data were confirmed. Moreover, it was demonstrated that the reaction mechanism
changes from the autocatalytic to the n-order regime during the reaction. An ROP mechanism is proposed at which the available
AlO4(OH)2 octahedra act as active sites shifting the curing exotherms to lower temperatures.
Ruthenium complexes are considered as the most favorable alternatives to traditional platinum-based cancer drugs owing to their acceptable toxicity level, selectivity, variant oxidation states and ability to treat platinum-resistant cancer cells. They have similar ligand exchange kinetics as platinum drugs but can be tailored according to our desire by ligands influence. In the current study, we illustrate the in-vitro anticancer profile of some ruthenium complexes (2016–2021) against human hepatocellular carcinoma (HepG2). The anticancer activity of ruthenium complexes is determined by comparing their IC 50 values with one another and positive controls. Fortunately, some ruthenium complexes including 3, 4, 6, 14, 15, 20, 42 , and 48 exhibit surpassed in-vitro anticancer profile than that of positive controls promising as potential candidates against liver cancer. We also explored the structure-activity relationship (SAR) which is a key factor in the rational designing and synthesis of new ruthenium drugs. It covers the factors affecting anticancer activity including lipophilicity, planarity, area and bulkiness, the steric influence of different ligands, and electronic effects induced by ligands, stability, aqueous solubility and bioavailability to the target sites. The data reported here will provide strong support in the plausible design and synthesis of ruthenium anticancer drugs in the upcoming days.
A triphenyl-pentacarboxylic acid, 3,5-di(2′,4′-dicarboxylphenyl)benzoic acid (H5ddba), was applied as an adaptable linker for the hydrothermal assembly of eight new metal(ii) coordination polymers (CPs) and complexes, formulated as [Cu2(μ-H3ddba)2(phen)2] (1), {[Cd2(μ4-Hddba)(phen)2(H2O)2]·2H2O}n (2), [M4(μ3-Hddba)2(2,2′-bipy)6(μ-H2O)]·6H2O (M = Ni (3), Mn (4)), {[Co2(μ5-Hddba)(μ-4,4′-bipy)1.5(H2O)]·H2O}n (5), {[Zn2(μ5-Hddba)(4,4′-bipy)1.5]·4,4′-bipy·2H2O}n (6), [Mn2(μ6-Hddba)(H2biim)(H2O)]n (7), and {[Cd2(μ7-ddba)(Hbpa)]·5H2O}n (8). The products 1-8 were generated from metal(ii) chlorides, H5ddba, and various N-donor supporting ligands acting as mediators of crystallization (i.e., phen: 1,10-phenanthroline; 2,2′-bipy: 2,2′-bipyridine; 4,4′-bipy: 4,4′-bipyridine; H2biim: 2,2′-biimidazole; or bpa: bis(4-pyridyl)amine). All compounds were analyzed by standard methods (C/H/N analysis, FTIR, TGA and PXRD) including single-crystal X-ray diffraction. The structural multiplicity of 1-8 ranges from discrete dimers (1) or tetramers (3 and 4) to a 1D coordination polymer (2) and 3D metal-organic frameworks (5-8). Topological analysis of simplified H-bonded or metal-organic networks disclosed fcu (1), 2C1 (2), dia (3 and 4), sra (6), 3,4,7T3 (8), and unprecedented (5 and 7) topologies. The catalytic activity of 1-8 was investigated in a model Knoevenagel condensation between benzaldehydes and malononitrile, resulting in up to 99% yields of condensation products. The substrate scope, catalyst recycling, and effects of different reaction parameters were investigated. Finally, this work extends the use of H5ddba as an aromatic pentacarboxylate building block for the design of new metal-organic architectures with captivating structures and functional properties.
