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1

Szkielety metalo-organiczne do zastosowań w zakresie ochrony środowiska

Baluk Mateusz Adam, Trzebiatowska Patrycja Jutrzenka, Pieczyńska Aleksandra

Wiadomości Chemiczne

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2024

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[Z] 78, 3-4

189--217

EN

Current challenges related to climate change, environmental degradation, and the increasing energy demand impose an urgent need for society to seek innovative solutions in environmental protection. In response to these issues, scientists have been developing areas related to novel functional nanomaterials for years. Among these materials, particular attention is drawn to metal-organic frameworks (MOFs), a new type of porous coordination polymers built from metal centers and organic ligands. The exceptional properties of MOFs come from their porous structure exhibiting high surface area, low density, large pore volume, also recyclability and the ability to regulate pore size and activity by selecting appropriate building blocks. MOFs can be synthesized by various routes and the most popular methods are the following: solvo-(hydro)thermal, mechanochemical, electrochemical, sonochemical or microwave-assisted synthesis. The type of synthesis influences the MOFs properties such as crystal size, specific surface area or possibility of scalable. Furthermore, MOFs activity in sorption or catalysis can be enhanced by postsynthetic modification (PSM), which enables the introduction of new functional groups or particles on/into MOF. Thanks to these properties and tunability, MOFs are finding increasingly broad applications in various processes that can serve different functions such as catalysts, photocatalysts, or sorbents. Due to the possibility of control of pore structure, their adsorption properties, and the nature of active sites, lately, MOFs and MOF-based materials have been investigated in gas adsorption and separation, hydrogen storage, CO2 capture, chemical sensing, electrochemical water splitting, biomass conversion, polymerization and drug delivery. This article will provide general information about the structure and key properties of MOFs, as well as methods of their synthesis and possibilities for modification. However, the focus will primarily be on indicating the various applications of MOFs in environmental applications (Figure 1). The use of MOFs in processes for removing organic and inorganic pollutants from water, air purification, gas separation, pollutant detection, and fuel generation and storage will be discussed. Additionally, the potential uses of MOFs as catalysts in transesterification processes, CO2 fixation, depolymerization, or biomass conversion will be highlighted.

2

Metal-organic frameworks for efficient drug adsorption and delivery

Hyjek Kornelia, Jodłowski Przemysław

Scientiae Radices

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2023

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Vol. 2, Iss. 2

115-189

EN

In recent years, the number of materials used as drug delivery systems (DDS) has increased dramatically. The widespread use of DDSs has improved both the safety and efficacy of therapy. The systems currently in use pose numerous drawbacks and require proper improvements. Although many modern materials are being developed, metal-organic frameworks (MOFs) deserve special attention. Thermal and chemical stability, high specific surface area, low toxicity, high biocompatibility, and great potential for modification are the main features enabling MOFs to be used as DDS. In this review, we describe MOFs, their structure, synthesis, and characterization, as well as drug loading, drug release kinetics, and bioassays. A critical approach is to outline the disadvantages as well as the limitations of MOFs and to identify areas that need to be studied more thoroughly. Nonetheless, the prospective nature of MOFs as DDS and potential adsorbents in overdose or poisoning is presented and highlighted.

3

Polimery koordynacyjne wanadu : stan obecny i perspektywy

Augustyniak Adam W.

Wiadomości Chemiczne

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2021

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[Z] 75, 3-4

253--269

EN

Vanadium ions are very attractive building units owing to their coordination diversity. In recent years, metal-organic polyhedra (MOP) and metal-organic frameworks (MOFs) have gradually become attractive materials in various fields due to their unique properties. However, despite this, structures based on vanadium ions are scarce. This short perspective review paper describes representative examples of MOP and MOFs based vanadium, focusing on their structure and their applications.

4

Modelling of porous metal-organic framework (MOF) materials used in catalysis

Kurzydym Izabela, Czekaj Izabela

Technical Transactions

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2020

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Vol. 117, iss. 1

art. no. e2020012

EN

This paper presents a review of modern modelling of porous materials such as metal-organic frameworks used in catalysis. The authors’ own research approach using the nano-design of metal-organic frameworks is included in this review.

PL

W niniejszym artykule przedstawiamy przegląd nowoczesnego modelowania materiałów porowatych, takich jak struktury metaloorganiczne, stosowanych w katalizie. Uwzględnione zostały również nasze własne prace badawcze wykorzystujące projektowanie struktur metaloorganicznych.

5

Katalizatory palladowe immobilizowane w materiałach typu MOF aktywne w reakcjach uwodornienia

Augustyniak Adam W., Trzeciak Anna M.

Wiadomości Chemiczne

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2019

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[Z] 73, 3-4

221--241

EN

Palladium immobilized in metal-organic frameworks (MOF) exhibit promising catalytic properties in hydrogenation of different unsaturated substrates. Due to the specific porous and crystalline structure MOFs can contribute in bonding and activation of organic substrates, increasing catalytic efficiency of Pd@MOF composites. The superior tunability of MOFs structures enables to design highly selective catalysts for hydrogenation of different substrates, such as olefins, esters, ketones, alcohols or alkynes. Due to the synergistic effects of palladium and MOF not only high activity but also high selectivity can be achieved. The article presents representative examples of MOF-based palladium catalysts for hydrogenation to illustrate perspectives, also technological, of their application.

6

Sieci metalo-organiczne jako multifunkcjonalne materiały przyszłości : mechanochemiczne podejście do syntezy

Jędrzejowski D.

Wiadomości Chemiczne

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2018

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[Z] 72, 9-10

645--666

EN

Metal-organic frameworks (MOFs) are a relatively new class of advanced inorganic-organic materials. Due to their modular structures and possible incorporation of various properties, that materials find more and more applications in many fields of science and industry. MOFs are coordination polymers, i.e. compounds with coordination bonds propagating infinitely in at least one dimension. Their characteristic feature is the presence of potential free spaces, i.e. pores. The free spaces often appear after proper activation, e.g. thermal activation. Other common properties of MOFs include for instance large specific surface areas and pore volumes, modifiable size and chemical environment of the pores, and network flexibility. All these properties result in the use of MOFs in e.g. selective sorption, separation or storage of gases, heterogeneous catalysis, design and fabrication of sensors, etc. During more than twenty years of the history of MOFs, many methods of their synthesis have been developed, including the most popular in solution at elevated temperatures (e.g. solvothermal method). Nevertheless, the activity of pro-ecological environments and the requirements set by international organizations encourage scientists to create new methods of synthesis, which, according to the guidelines presented by the 12 principles of green chemistry, will be safer, less aggressive, less toxic and less energy-consuming. One of the answers to meet these requirements is the use of mechanosynthesis. Mechanochemical synthesis relies on the supply of energy to a system by mechanical force, by grinding or milling. By combining or transforming solids in this way, the presence of a solvent, which is most often the main source of contamination and waste, can be minimised or completely excluded. Mechanical force is typically used for purposes other than MOF synthesis, e. g. catalyst grinding. Nevertheless, the use of mechanical force in synthesis is becoming more and more popular. The most important advantages of this approach, apart from its environmental impact, are very high efficiency (usually close to 100%) and drastically reduced reaction time. Of course, there are examples where these advantages are not observed. In such cases, mechanosynthetic modifications are introduced, such as e.g. addition of small amount of liquid (Liquid-Assisted Grinding) and/or a small addition of simple inorganic salt (Ion- and Liquid-Assisted Grinding). Furthermore, new instrument setups are being developed to monitor reaction mixtures in situ during mechanosynthesis, e.g. by use of such techniques as powder X-ray diffraction and Raman spectroscopy. This enables valuable insights into mechanisms and allows for mechanosynthesis optimization.

7

Przewodnictwo protonowe w sieciach metalo-organicznych : nowe możliwości w technologii ogniw paliwowych

Szufla M.

Wiadomości Chemiczne

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2018

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[Z] 72, 3-4

147--163

EN

Nowadays energy demands are huge and still increasing. This fact drives the search for modern technologies which are economically advantageous and environmentally friendly. A fuel cell technology is one of many solutions and hydrogen fuel cells are especially important. The essential element of such a cell is the electrolytic membrane which makes proton transfer possible. In this article, selected examples of metal-organic frameworks (MOFs) that can be used as proton-conducting membranes are described. Porous structure of such materials as well as the existence of proton-donating and accepting groups on their pore walls allow for creation of hydrogen bonding network enabling the proton hopping (Grotthuss’s conduction mechanism). The conduction can also occur on the way of diffusion of bigger ions, e.g. H3O+ (vehicular conduction mechanism) Proton conducting MOFs can be divided according to temperature in which these materials can operate. There are two regimes – below 100°C – conductivity in MOFs is aided by the presence of water molecules, and above 100°C – conductivity does not depend on humidity. Important group among MOFs conductive under low-temperature conditions are oxalate-based frameworks. Taking into account synthetic methods, interesting case is the MOF reported by Matoga and co-workers, which was obtained on the way of economically and environmentally friendly mechanosynthesis. High proton conductivity in metal-organic frameworks can be achieved not only when channels are filled with water molecules but also by introduction of non- -volatile organic compounds to framework voids or by incorporating them into the framework. Imidazole, 1,2,4-triazole, pyrazoline or histamine may play the role of such compounds. Remarkable examples of this strategy include the MOF reported by Kitagawa and co-workers, where 1,2,4-triazole molecules are incorporated into the framework as well as the material in which proton conduction occurs owing to the presence of imidazole guest molecules.

8

An in Situ Crystal Growth of Metal Organic Frameworks-5 on Electrospun PVA Nanofibers

Talmoudi H., Khenoussi N., Adolphe D., Said A. H., Schacher L.

Autex Research Journal

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2018

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Vol. 18, no. 3

308--313

EN

In this study, a simple, general and straightforward method for growing metal-organic frameworks (MOFs) crystals directly on nanofibers is presented. A chelating polymer was first blent with metal cation and then electrospun. The obtained nanofibers were immersed in a linker solution. Metal cations were released and the metal-organic frameworks crystals were grown on the fibers’ surface. In this work, this method was tested with polyvinyl alcohol as chelating polymer, Zn2+ as metal cation and Terephthalic acid as linker. The pair cation/linker corresponds to the MOF-5. The latter is a robust metal organic framework formed from Zn4O nodes with 1,4-benzodicarboxylic acid struts between the nodes. SEM images revealed that the MOF-5 nanocrystals have grown along the PVA/Zn2+ nanofibers that served as the crystals’ growth template by providing the Zn2+ ions. This result was also confirmed by infrared spectroscopy, which indicates the presence of characteristic bands of MOF-5 in the modified nanofibers spectrum. Moreover, the X-ray diffraction showed that MOF-5 material was well crystallized on the nanofibers surface according to a cubic symmetry with a space group Fm-3m and a lattice constant a = 25.8849 Å.

9

Otrzymywanie i właściwości adsorpcyjne sieci metaloorganicznych

Szeligowska S., Choma J., Jaroniec M.

Wiadomości Chemiczne

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2017

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[Z] 71, 5-6

299--322

EN

MOF materials or metal-organic frameworks are compounds consisting of metal ions or clusters (metal junctions) and organic ligands (bridging groups) connected via coordination bonds. Since a variety of organic ligands and metal junctions is available, metal-organic frameworks of desired composition and structures can be synthesized. These compounds are relatively new, intensively studied, their number is continuously growing from year to year. Metalorganic frameworks may also possess elastic properties due to the presence of coordination bonds in their structure. A distinct feature of MOF materials, which differentiates them from other sorbents, is the possibility of changing their pore structure under influence of external stimuli and the ability of adjusting their pore size to the dimensions of the adsorbed molecules. An interesting phenomenon observed in these materials is the so-called “breathing” effect that is manifested by drastic changes in the pore volume upon external stimuli such as temperature, pressure, type of adsorbate, presence of solvent. There are numerous methods for the preparation of MOF materials: solvothermal, electrochemical, mechanochemical, sonochemical and microwave-assisted syntheses. An additional activation of these materials is often required to remove the remaining solvents from pores and consequently, increase their adsorption capacity. The latter can be also increased by additional modifications that can be used to tune their physicochemical properties, and especially porosity. Due to the excellent adsorption properties of MOF, especially very high BET specific surface area (up to 6200 m2/g) and large pore volume, these materials have been intensively studied for capture or storage of various gases such as CO2, H2 and CH4. Applications of metal-organic frameworks are continuously growing and range from gas storage, chemical sensors and phosphors to medicine, where they are used as drug carriers.

10

Kompozyty z materiałów węglowych i metalo-organicznych (MOF)

Bieniek A., Wiśniewski M., Terzyk A. P., Bolibok P., Dembek M.

Inżynieria i Ochrona Środowiska

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2016

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T. 19, nr 3

319--329

EN

The paper presents a brief review of the literature in the field of composites made of carbon materials and MOF structures. It focuses on presenting numerous examples of composites and the positive effects of the merger of these groups of materials. The new class of composites combines carbon materials with the functionality of inorganic materials. These composites offer a chance to eliminate weaknesses and enhance the capacity of each group. These composites proved that integrating MOF materials with carbonaceous materials can not only convert a significant weakness of MOF, but also surprisingly bring many new features such as improved resistance, i.e. for moisture, and electrical conductivity. These composites broaden the horizons of applications in the fields of adsorption, separation, catalysis, electrochemistry and sensors. In the future, using a variety of MOF structures and carbonaceous materials, newly formed composites will probably push the boundaries of cognition in many fields.

PL

Praca przedstawia krótki przegląd literaturowy z zakresu kompozytów złożonych z materiałów węglowych oraz materiałów metalo-organicznych (ang. metal-organic frameworks, MOF). Skupia się na zaprezentowaniu licznych przykładów tworzenia kompozytów z powyższych grup materiałów oraz ukazaniu pozytywnych efektów takiego postępowania. Nowa klasa kompozytów łączy cechy materiałów węglowych z funkcjonalnością materiałów nieorganicznych. Kompozyty te dają szansę na wyeliminowanie wad i lepsze wykorzystanie potencjału każdej z grup. Poprzez integrację materiałów MOF z materiałami węglowymi można nie tylko znacząco zminimalizować wady MOF, ale, co więcej, uzyskać wiele nowych funkcji, takich jak poprawa odporności, np. na wilgoć, czy przewodności elektrycznej. Dzięki tym kompozytom poszerzają się horyzonty aplikacyjne w dziedzinach adsorpcji, separacji, katalizy, a także elektrochemii i sensorów. W przyszłości korzystając z różnorodności struktur MOF i materiałów węglowych, nowo powstałe kompozyty, podobnie jak MOF i materiały węglowe, być może pozwolą przesunąć granice poznawcze w wielu dziedzinach.

11

Homochiral metal-organic framework [Zn2(d-Cam)2(4,4′-bpy)]n for high-resolution gas chromatographic separations

Xue X. D, Zhang M., Xie S. M, Yuan L. M

Acta Chromatographica

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2015

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Vol. 27, no. 1

15--26

EN

The metal-organic framework (MOF) is a kind of new type self-assembly porous coordination polymer, which possesses many characteristics such as homologic hole, controllable size of cave, high specific surface area, and good chemical stability. In this study, a three-dimensional framework [Zn2(d-Cam)2(4,4′-bpy)]n with large homochiral channel and the orderly arrangement of left- and right-handed helices was used as chiral stationary phases (CSPs) in gas chromatography (GC). [Zn2(d-Cam)2 (4,4′-bpy)]n-coated open tubular column was prepared by a dynamic coating method for high-resolution GC. Some racemates, isomers, linear alkanes, and alcohols are used as the targets for separation. The column coating properties efficiency, polarity, and selectivity were studied. The experimental results show that the stationary phase has outstanding selectivity and also possesses good recognition ability toward these compounds.

12

Znaczenie mikroporowatych materiałów metaloorganicznych (MOF ) dla potrzeb magazynowania wodoru

Czub J., Gondek Ł, Figiel H.

Wiadomości Chemiczne

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2012

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[Z] 66, 3-4

227-247

EN

Currently, the metal-organic frameworks (MOF s) are considered among the most promising materials for hydrogen storage. In this paper, the properties of MOF s that are particularly important for application purposes are presented. Examples include simplicity of their syntheses on an industrial scale, low synthesis costs, high thermal stability and durability, an excellent repeatability and very low degree of degradation during cyclic hydrogen loading and recovery. On the other hand, the potential use of MOF s as hydrogen reservoirs is to some extent limited due to the fact that the low temperatures of 77 K are required for effective adsorption of hydrogen in the microporous structures of MOF s. Nowadays, the research on MOF s is carried in two directions. In particular, there are intensive studies on increasing of the concentration of hydrogen adsorbed at low temperatures in order to determine the limiting value for which maintaining the reservoir at the temperature of liquid hydrogen would be economically viable. It seems that the limiting concentration is being currently reached. The second direction of research is to increase the limiting value of temperature at which the concentration of adsorbed hydrogen is acceptable.