Materials capable of the safe and efficient capture or degradation of toxic chemicals, including chemical warfare agents (CWAs) and toxic industrial chemicals (TICs), are critically important in the ...modern age due to continuous threats of these chemicals to human life, both directly and indirectly. Metal–organic frameworks (MOFs), atomically precise hybrid materials that are synthesized via the self-assembly of metal cations or clusters and organic linkers, offer a unique solid adsorbent design platform due to their great synthetic versatility. This review will focus on recent advancements in MOF-based adsorbent design for protection against chemical warfare agents (organophosphorus nerve agents, blistering agents, and their simulants) and toxic industrial chemicals such as H2S, NH3, SO2, CO, NO2, and NO.
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Organophoshorus nerve agents are among the most toxic chemicals known to humans, and because of their unfortunate recent use despite international bans, there is an urgent need to develop materials ...that can effectively degrade these nerve agents. Within the past decade, zirconium-based metal–organic frameworks (Zr-MOFs) have emerged as a bioinspired class of materials capable of rapidly hydrolyzing these compounds and significantly diminishing their toxicity. Both experimental and computational insights have guided the design of Zr-MOFs, leading to the development of catalysts capable of detoxifying nerve agents and simulants, chemicals with similar functionality but lower toxicity, via hydrolysis within seconds in basic aqueous solutions. While these systems are acceptable for the elimination of stockpile weapons, translating this catalytic performance to filters incorporating Zr-MOFs that can be used in masks or protective clothing is not trivial. As such, a large area of focus recently has been targeted toward integrating these hydrolysis catalysts into protective clothing and gear while retaining the performance from solution-based catalytic systems. This Forum Article provides an overview of the development of Zr-MOFs for the catalytic hydrolysis of organophosphorus substrates, including design principles and mechanistic insights for both solution-based and textile-coated systems. Finally, we highlight the remaining challenges yet to be addressed and offer perspectives on the future directions for this field.
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CD-MOF, an extended framework incorporating the
C
8
symmetric cyclic oligosaccharide, γ-cyclodextrin (γ-CD), is based on the coordination of alkali metal cations to alternating α-1,4-linked
d
...-glucopyranosyl units on the primary and secondary faces of the γ-CD tori. Here, we report the synthesis and characterisation of an amino-functionalised CD-MOF that is isostructural with pristine CD-MOF and adsorbs CO
2
permanently.
A CD-MOF is prepared from amino-functionalized (blue moon) γ-CD, which permanently captures CO
2
as a carbamate (red moon).
The scope and limitations of the alkylation of closo-B12(OH)122- using a series of fourteen alkyl and aralkyl halides and two p-toluenesulfonic acid esters in the presence of ...N,N-diisopropylethylamine have been investigated. The dodecaalkoxy-closo-dodecaborate products, closo-B12(OR)122-, and their hypercloso two-electron oxidation products have been explored. The species closo-B12(OR)122- containing 26 cage-bonding electrons may undergo two reversible, sequential, one-electron oxidation processes, producing a 25-electron radical anion and a 24-electron neutral species. Several oxidizing reagents were investigated for the chemical oxidation of closo-B12(OR)122- and hypercloso-B12(OR)12- to hypercloso-B12(OR)12. Both FeCl3 . 6H2O and K3Fe(CN)6 in 90/5/5 ethanol/acetonitrile/H2O were found to be the reagents of choice. The reverse reaction leading from the neutral species to the radical anion and subsequently to the dianion was achieved using sodium borohydride in ethanol. A variety of alkoxyl derivatives have been synthesized by heating the reactants for extended periods of time in acetonitrile at the reflux temperature. The use of elevated reaction temperatures attained by employing moderate argon pressure (autoclave) over the reaction mixture led to drastic reductions in reaction times and increased efficiency. X-ray diffraction studies of substituted dodecabenzyl ether derivatives proved that 2 2- has approximate I h symmetry while hypercloso-2, -3, -9, -11, -12, and -13 have approximate D 3 d point group symmetry due to Jahn−Teller distortion from I h .
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Hydrogen-bonded organic frameworks (HOFs), self-assembled from strategically pre-designed molecular tectons with complementary hydrogen-bonding patterns, are rapidly evolving into a novel and ...important class of porous materials. In addition to their common features shared with other functionalized porous materials constructed from modular building blocks, the intrinsically flexible and reversible H-bonding connections endow HOFs with straightforward purification procedures, high crystallinity, solution processability, and recyclability. These unique advantages of HOFs have attracted considerable attention across a broad range of fields, including gas adsorption and separation, catalysis, chemical sensing, and electrical and optical materials. However, the relatively weak H-bonding interactions within HOFs can potentially limit their stability and potential use in further applications. To that end, this Perspective highlights recent advances in the development of chemically and thermally robust HOF materials and systematically discusses relevant design rules and synthesis strategies to access highly stable HOFs.
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Metal–organic frameworks (MOFs), a versatile class of porous materials that exhibit high specific surface areas, controllable structures, and tunable pores, have been identified as a promising ...platform in the field of electrochemistry in recent years, and researchers have now designed MOFs specific to electrochemical applications. In this review, we describe the recent uses of MOFs and their composites for use in electrochemical sensing, electrocatalysis, and electrochemical energy storage devices (e.g., batteries and supercapacitors), followed by an overview of the remaining challenges and viewpoints for MOF-based materials for these applications.
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Wearable personal protective equipment that is decorated with photoactive self‐cleaning materials capable of actively neutralizing biological pathogens is in high demand. Here, we developed a series ...of solution‐processable, crystalline porous materials capable of addressing this challenge. Textiles coated with these materials exhibit a broad range of functionalities, including spontaneous reactive oxygen species (ROS) generation upon absorption of daylight, and long‐term ROS storage in dark conditions. The ROS generation and storage abilities of these materials can be further improved through chemical engineering of the precursors without altering the three‐dimensional assembled superstructures. In comparison with traditional TiO2 or C3N4 self‐cleaning materials, the fluorinated molecular coating material HOF‐101‐F shows a 10‐ to 60‐fold enhancement of ROS generation and 10‐ to 20‐fold greater ROS storage ability. Our results pave the way for further developing self‐cleaning textile coatings for the rapid deactivation of highly infectious pathogenic bacteria under both daylight and light‐free conditions.
A series of solution‐processable, crystalline porous materials were prepared and used as textiles coatings to spontaneously convert absorbed oxygen from air into reactive oxygen species (ROS) upon absorption of daylight, and long‐termly store ROS in dark conditions. This work paves the way for further developing self‐cleaning textile coatings for the rapid deactivation of highly infectious pathogenic bacteria under both daylight and light‐free conditions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The connectivity of NU-1000, a metal-organic framework, gives rise to Zr6 nodes with hydroxyl-containing functional groups pointing into the large 1D mesoporous hexagonal channels of the framework. ...These free and exposed -OH groups are ideal grafting sites, and they can be easily tailored to serve a specific function. Through atomic layer deposition in MOFs (AIM), we demonstrate the ability to form several oxides with atomic precision at the exposed -OH sites of NU-1000. Importantly, this process occurs without changing the overall structure of the framework. Recent progress in scaling AIM process of the ultrahigh surface area (2300 m2/g) framework as well as progress in pinpointing the location and mechanism of surface chemical reactions of catalytically relevant metals is discussed. Computational, synchrotron, and in-situ analytical methods including DFT, differential electron diffraction, and in situ FTIR are brought to bear on several new metal systems, many of which show remarkably self-limiting behavior.
To grow films of Cu
2
O, bis-(dimethylamino-2-propoxide)Cu(
ii
), or Cu(dmap), is used as an atomic layer deposition precursor using only water vapor as a co-reactant. Between 110 and 175 °C, a ...growth rate of 0.12 ± 0.02 Å per cycle was measured using an
in situ
quartz crystal microbalance (QCM). X-ray photoelectron spectroscopy (XPS) confirms the growth of metal-oxide films featuring Cu(
i
).
To grow films of Cu
2
O, bis-(dimethylamino-2-propoxide)Cu(
ii
), or Cu(dmap), is used as an atomic layer deposition precursor using only water vapor as a co-reactant.
Metal–organic frameworks with Zr6 nodes, UiO-66 and NU-1000, were investigated as supports for Ir(CO)2 and Ir(C2H4)2 complexes. A single bonding site for the iridium is identified on the nodes of ...NU-1000, whereas two sites are identified on UiO-66, although at low iridium loadings only one site is occupied. Density functional theory calculations provide structural results that are in good agreement with infrared and X-ray absorption fine-structure spectra. The reactivity of node-supported Ir(CO)2 with C2H4 and the catalytic activity and selectivity of the species initially present as Ir(C2H4)2 for ethylene hydrogenation and dimerization were investigated both experimentally and computationally and shown to be strongly influenced by the node.
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