The mercury removal efficiency of a novel metal‐organic framework (MOF) derived from the amino acid S‐methyl‐L‐cysteine is presented and the process is characterized by single‐crystal X‐ray ...crystallography. A feasibility study is further presented on the performance of this MOF—and also that of another MOF derived from the amino acid L‐methionine—when used as the sorbent in mixed matrix membranes (MMMs). These MOF‐based MMMs exhibit high efficiency and selectivity—in both static and dynamic regimes—in the removal of Hg2+ from aqueous environments, due to the high density of thioalkyl groups decorating MOF channels. Both MMMs are capable to reduce different concentration of the pollutant to acceptable limits for drinking water (<2 parts per billion). In addition, a novel device, consisting of the recirculation and adsorption of contaminated solutions through the MOF–MMMs, is designed and successfully explored in the selective capture of Hg2+. Thus, filtration of Hg2+ solutions with multiple passes through the permeation cell shows a gradual decrease of the pollutant concentration. These results suggest that MOF‐based MMMs can be implemented in water remediation, helping to reduce either contaminants from accidental unauthorized or deliberate metal industrial dumping and to ensure access for clean and potable freshwater.
The potential of metal‐organic frameworks (MOFs) and MOF‐based membranes in water remediation receives a very important boost with the reported results. New MOF‐based membranes are testified as sustainable, effective, and cheap solution for mercury decontamination to get drinking water, with the potential of minimizing the impact of this pollutant on the environment and human bodies.
The gram‐scale synthesis, stabilization, and characterization of well‐defined ultrasmall subnanometric catalytic clusters on solids is a challenge. The chemical synthesis and X‐ray snapshots of Pt02 ...clusters, homogenously distributed and densely packaged within the channels of a metal–organic framework, is presented. This hybrid material catalyzes efficiently, and even more importantly from an economic and environmental viewpoint, at low temperature (25 to 140 °C), energetically costly industrial reactions in the gas phase such as HCN production, CO2 methanation, and alkene hydrogenations. These results open the way for the design of precisely defined catalytically active ultrasmall metal clusters in solids for technically easier, cheaper, and dramatically less‐dangerous industrial reactions.
The multigram synthesis of Pt02 clusters within a metal–organic framework (MOF) is presented. The high stability and crystallinity of the selected MOF offers an unprecedented characterization of such ultrasmall entities. This hybrid material catalyzes important industrial reactions efficiently and at low temperature, such as HCN production, CO2 methanation, and alkene hydrogenations.
Proton conduction in solids attracts great interest, not only because of possible applications in fuel cell technologies, but also because of the main role of this process in many biological ...mechanisms. Metal–organic frameworks (MOFs) can exhibit exceptional proton-conduction performances, because of the large number of hydrogen-bonded water molecules embedded in their pores. However, further work remains to be done to elucidate the real conducting mechanism. Among the different MOF subfamilies, bioMOFs, which have been constructed using biomolecule derivatives as building blocks and often affording water-stable materials, emerge as valuable systems to study the transport mechanisms involved in the proton-hopping dynamics. Herein, we report a versatile chiral three-dimensional (3D) bioMOF, exhibiting permanent porosity, as well as high chemical, structural, and water stability. Moreover, the choice of this suitable bioligand results in proton conductivity, and allows us to propose a proton-conducting mechanism based on experimental data, which are displayed visually by means of quantum molecular dynamics simulations.
A novel ZnII biological metal–organic framework mimics β‐lactamase enzymes. The crystal structure of a novel Zn‐based biological MOF occupies the central position to reflect the crucial role that its ...porous functional channels play in the capture, immobilization and degradation of amoxicillin. The crystal structures of amoxicillin and the degraded derivative surround the MOF, indicating the differences in the antibiotic before and after entering the bioMOF. More information can be found in the Research Article by J. Ferrando‐Soria, D. Armentano, A. Leyva‐Pérez, E. Pardo and co‐workers (DOI: 10.1002/chem.202301325).
The lack of rational design methodologies to obtain chiral rod-based MOFs is a current synthetic limitation that hampers further expansion of MOF chemistry. Here we report a metalloligand design ...strategy consisting of the use, for the first time, of preformed 1D rodlike SBUs (1) for the rational preparation of a chiral 3D MOF (2) exhibiting a rare eta net topology. The encoded chiral information on the enantiopure ligand is efficiently transmitted first to the preformed helical 1D building block and, in a second stage, to the resulting chiral 3D MOF. These results open new routes for the rational design of chiral rod-based MOFs, expanding the scope of these unique porous materials.
The combination of high crystallinity and rich host‐guest chemistry in metal‐organic frameworks (MOFs), have situated them in an advantageous position, with respect to traditional porous materials, ...to gain insight on specific weak noncovalent supramolecular interactions. In particular, sulfur σ‐hole interactions are known to play a key role in the biological activity of living beings as well as on relevant molecular recognitions processes. However, so far, they have been barely explored. Here, we describe both how the combination of the intrinsic features of MOFs, especially the possibility of using single‐crystal X‐ray crystallography (SCXRD), can be an extremely valuable tool to gain insight on sulfur σ‐hole interactions, and how their rational exploitation can be enormously useful in the efficient removal of harmful organic molecules from aquatic ecosystems. Thus, we have used a MOF, prepared from the amino acid L‐methionine and possessing channels decorated with −CH2CH2SCH3 thioalkyl chains, to remove a family of organic dyes at very low concentrations (10 ppm) from water. This MOF is able to efficiently capture the four dyes in a very fast manner, reaching within five minutes nearly the maximum removal. Remarkably, the crystal structure of the different organic dyes within MOFs channels could be determined by SCXRD. This has enabled us to directly visualize the important role sulfur σ‐hole interactions play on the removal of organic dyes from aqueous solutions, representing one of the first studies on the rational exploitation of σ‐hole interactions for water remediation.
A metal‐organic framework, with functional channels decorated with −CH2CH2SCH3 thioalkyl chains, does not only exhibit outstanding capture properties for organic dyes but also establishes that sulfur σ‐hole interactions play a prominent role with the help of single crystal X‐ray diffraction.
We report two new highly crystalline metal–organic frameworks (MOFs), derived from the natural amino acids serine (1) and threonine (2), featuring hexagonal channels densely decorated with hydroxyl ...groups belonging to the amino acid residues. Both 1 and 2 are capable of discriminating, via solid-phase extraction, a mixture of selected chloride salts of lanthanides on the basis of their size, chemical affinity, and/or the flexibility of the network. In addition, this discrimination follows a completely different trend for 1 and 2 because of the different locations of the hydroxyl groups in each compound, which is evocative of steric complementarity between the substrate and receptor. Last but not least, the crystal structures of selected adsorbates could be resolved, offering unprecedented snapshots on the capture process and enabling structural correlations with the separation mechanism.
Porous organic molecular materials (POMMs) are a novel class of porous materials that cover a wide range of organic‐based molecular building blocks connected through weak supramolecular interactions, ...such as hydrogen bonds, π‐π stacking, van der Waals and electrostatic interactions. Despite of their diverse chemical and structural nature, common features to POMMs include solution processability, crystallinity and microporosity. Herein, we focus, for the first time, on the advance of the field of POMMs beyond the archetypical microporosity. In particular, we highlight relevant examples of meso‐ and macroporous POMMs, as well as hierchachical ones (micro‐/meso‐, micro‐/macro‐ and meso‐/macroporous). We also remark some of their unique properties, and how they can be key in many applications.
The level of porosity beyond the microporous regime in Porous Organic Molecular Materials (POMMs) will trigger a shift in porous materials, rendering fascinating and unique opportunities in many applications. In this minireview, we summarize the recent advances in the synthesis of meso‐ and/or macroporous and hierarchical POMMs, highlighting some of their current applications.
Circumventing the impact of agrochemicals on aquatic environments has become a necessity for health and ecological reasons. Herein, we report the use of a family of five eco-friendly water-stable ...isoreticular metal–organic frameworks (MOFs), prepared from amino acids, as adsorbents for the removal of neonicotinoid insecticides (thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid) from water. Among them, the three MOFs containing thioether-based residues show remarkable removal efficiency. In particular, the novel multivariate MOF {SrIICuII 6(S,S)-methox1.5(S,S)-Mecysmox1.50(OH)2(H2O)}·36H2O (5), featuring narrow functional channels decorated with both −CH2SCH3 and −CH2CH2SCH3 thioalkyl chainsfrom l-methionine and l-methylcysteine amino acid-derived ligands, respectivelystands out and exhibits the higher removal efficiency, being capable to capture 100% of acetamiprid and thiacloprid in a single capture step under dynamic solid-phase extraction conditionsless than 30 s. Such unusual combination of outstanding efficiency, high stability in environmental conditions, and low-cost straightforward synthesis in 5 places this material among the most attractive adsorbents reported for the removal of this type of contaminants.
Single‐ion magnets (SIMs) are the smallest possible magnetic devices and are a controllable, bottom‐up approach to nanoscale magnetism with potential applications in quantum computing and ...high‐density information storage. In this work, we take advantage of the promising, but yet insufficiently explored, solid‐state chemistry of metal–organic frameworks (MOFs) to report the single‐crystal to single‐crystal inclusion of such molecular nanomagnets within the pores of a magnetic MOF. The resulting host–guest supramolecular aggregate is used as a playground in the first in‐depth study on the interplay between the internal magnetic field created by the long‐range magnetic ordering of the structured MOF and the slow magnetic relaxation of the SIM.
Molecular magnetism meets MOFs! A unique example of solid‐state incorporation of a single‐ion magnet (SIM) within the pores of a magnetic 3D MOF in a single‐crystal to single‐crystal process is shown. The resulting host–guest supramolecular aggregate affords the first deep study on the interplay between the internal magnetic field of the MOF and the slow magnetic relaxation of the SIM (see figure).
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