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1. Uptake of N2O5 by aqueous aerosol unveiled using chemically accurate many-body potentials

   https://doi.org/10.1038/s41467-022-28697-8  

   Cruzeiro, Vinícius Wilian ; Galib, Mirza ; Limmer, David T. ; Götz, Andreas W. ( December 2022 , Nature Communications)

   Abstract The reactive uptake of N 2 O 5 to aqueous aerosol is a major loss channel for nitrogen oxides in the troposphere. Despite its importance, a quantitative picture of the uptake mechanism is missing. Here we use molecular dynamics simulations with a data-driven many-body model of coupled-cluster accuracy to quantify thermodynamics and kinetics of solvation and adsorption of N 2 O 5 in water. The free energy profile highlights that N 2 O 5 is selectively adsorbed to the liquid–vapor interface and weakly solvated. Accommodation into bulk water occurs slowly, competing with evaporation upon adsorption from gas phase. Leveraging the quantitative accuracy of the model, we parameterize and solve a reaction–diffusion equation to determine hydrolysis rates consistent with experimental observations. We find a short reaction–diffusion length, indicating that the uptake is dominated by interfacial features. The parameters deduced here, including solubility, accommodation coefficient, and hydrolysis rate, afford a foundation for which to consider the reactive loss of N 2 O 5 in more complex solutions. 

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2. Emerging contaminants uptake by an Ultisol and a Vertisol from Puerto Rico

   https://doi.org/10.1002/agg2.20022  

   Flores‐Mangual, Mario L. ; Hernández‐Maldonado, Arturo J. ; Ortíz‐Martínez, Krisiam ; Quiñones, Natasha P. ( April 2020 , Agrosystems, Geosciences & Environment)

   Contaminants of emerging concern (CECs), including pharmaceutical compounds, have been found in irrigation waters and have found their way into crops through the uptake of contaminated water. Many farms in Puerto Rico are irrigated with water that might have considerable levels of CECs. The objective of this study was to determine the quantity of commonly detected CEC adsorbed onto soil particles of two contrasting tropical soils of Puerto Rico (Fraternidad, basic Vertisol [fine, smectitic, isohyperthermic Typic Haplusterts], and Mariana series, acid Ultisol [fine, mixed, active, isohyperthermic Typic Haplohumults]). A CECs single point and multicomponent adsorption experiments were carried out using the batch equilibrium technique. The CECs were naproxen (NPX), O‐desmethylnaproxen (O‐DesNPX), caffeine (CFN), paraxanthine (PX), carbamazepine (CBZ), carbamazepine‐10, 11‐epoxide (Ep‐CBZ), clofibric acid (ClofA), and salicylic acid (SA). The CEC concentrations in water before and after adsorption were determined using a triple quadrupole mass spectroscopy liquid chromatography. The results showed that SA was highly adsorbed by both soils, although in greater concentrations in Fraternidad than Mariana, probably because of greater cation‐bridging. Paraxanthine was adsorbed only in the multicomponent test, probably as a co‐adsorbate. Caffeine, CBZ, and their metabolites were adsorbed in both soils in lesser concentrations than SA and PX. However, NPX and ClofA were not adsorbed by either soil type. Thus, these CECs could potentially move more freely through the soil matrix and reach soil roots in greater quantities than other contaminants.

    

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3. Ortho ‐Alkoxy‐benzamide Directed Formation of a Single Crystalline Hydrogen‐bonded Crosslinked Organic Framework and Its Boron Trifluoride Uptake and Catalysis

   https://doi.org/10.1002/ange.202311601  

   Li, Fangzhou ; Li, Errui ; Samanta, Krishanu ; Zheng, Zhaoxi ; Wu, Lianqian ; Chen, Albert D. ; Farha, Omar K. ; Staples, Richard J. ; Niu, Jia ; Schmidt‐Rohr, Klaus ; et al ( November 2023 , Angewandte Chemie)

   Boron trifluoride (BF₃) is a highly corrosive gas widely used in industry. Confining BF₃in porous materials ensures safe and convenient handling and prevents its degradation. Hence, it is highly desired to develop porous materials with high adsorption capacity, high stability, and resistance to BF₃corrosion. Herein, we designed and synthesized a Lewis basic single‐crystalline hydrogen‐bond crosslinked organic framework (H_COF‐50) for BF₃storage and its application in catalysis. Specifically, we introduced self‐complementaryortho‐alkoxy‐benzamide hydrogen‐bonding moieties to direct the formation of highly organized hydrogen‐bonded networks, which were subsequently photo‐crosslinked to generate H_COFs. The H_COF‐50 features Lewis basic thioether linkages and electron‐rich pore surfaces for BF₃uptake. As a result, H_COF‐50 shows a record‐high 14.2 mmol/g BF₃uptake capacity. The BF₃uptake in H_COF‐50 is reversible, leading to the slow release of BF₃. We leveraged this property to reduce the undesirable chain transfer and termination in the cationic polymerization of vinyl ethers. Polymers with higher molecular weights and lower polydispersity were generated compared to those synthesized using BF₃ ⋅ Et₂O. The elucidation of the structure–property relationship, as provided by the single‐crystal X‐ray structures, combined with the high BF₃uptake capacity and controlled sorption, highlights the molecular understanding of framework‐guest interactions in addressing contemporary challenges.

    

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4. Ortho ‐Alkoxy‐benzamide Directed Formation of a Single Crystalline Hydrogen‐bonded Crosslinked Organic Framework and Its Boron Trifluoride Uptake and Catalysis

   https://doi.org/10.1002/anie.202311601  

   Li, Fangzhou ; Li, Errui ; Samanta, Krishanu ; Zheng, Zhaoxi ; Wu, Lianqian ; Chen, Albert D. ; Farha, Omar K. ; Staples, Richard J. ; Niu, Jia ; Schmidt‐Rohr, Klaus ; et al ( November 2023 , Angewandte Chemie International Edition)

   Boron trifluoride (BF₃) is a highly corrosive gas widely used in industry. Confining BF₃in porous materials ensures safe and convenient handling and prevents its degradation. Hence, it is highly desired to develop porous materials with high adsorption capacity, high stability, and resistance to BF₃corrosion. Herein, we designed and synthesized a Lewis basic single‐crystalline hydrogen‐bond crosslinked organic framework (H_COF‐50) for BF₃storage and its application in catalysis. Specifically, we introduced self‐complementaryortho‐alkoxy‐benzamide hydrogen‐bonding moieties to direct the formation of highly organized hydrogen‐bonded networks, which were subsequently photo‐crosslinked to generate H_COFs. The H_COF‐50 features Lewis basic thioether linkages and electron‐rich pore surfaces for BF₃uptake. As a result, H_COF‐50 shows a record‐high 14.2 mmol/g BF₃uptake capacity. The BF₃uptake in H_COF‐50 is reversible, leading to the slow release of BF₃. We leveraged this property to reduce the undesirable chain transfer and termination in the cationic polymerization of vinyl ethers. Polymers with higher molecular weights and lower polydispersity were generated compared to those synthesized using BF₃ ⋅ Et₂O. The elucidation of the structure–property relationship, as provided by the single‐crystal X‐ray structures, combined with the high BF₃uptake capacity and controlled sorption, highlights the molecular understanding of framework‐guest interactions in addressing contemporary challenges.

    

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5. Insights into dual-functional modification for water stability enhancement of mesoporous zirconium metal–organic frameworks

   https://doi.org/10.1039/D2TA03851J  

   Liu, Jian ; Anderson, Ryther ; Schmalbach, Kevin M. ; Sheridan, Thomas R. ; Wang, Zhao ; Schweitzer, Neil M. ; Stein, Andreas ; Mara, Nathan A. ; Gomez-Gualdron, Diego ; Hupp, Joseph T. ( August 2022 , Journal of Materials Chemistry A)

   The stability of metal–organic frameworks (MOFs) in water affects their ability to function as chemical catalysts, their capacity as adsorbents for separations in water vapor presence, and their usefulness as recyclable water harvesters. Here, we have examined water stability of four node-modified variants of the mesoporous MOF, NU-1000, namely formate-, Acac-, TFacac-, and Facac-NU-1000, comparing these with node-accessible NU-1000. These NU-1000 variants present ligands grafted to NU-1000's hexa-Zr( iv )-oxy nodes by displacing terminal aqua and hydroxo ligands. Facac-NU-1000, containing the most hydrophobic ligands, showed the greatest water stability, being able to undergo at least 20 water adsorption/desorption cycles without loss of water uptake capacity. Computational studies revealed dual salutary functions of installed Facac ligands: (1) enhancement of framework mechanical stability due to electrostatic interactions; and (2) transformation and shielding of the otherwise highly hydrophilic nodes from H-bonding interactions with free water, presumably leading to weaker channel-stressing capillary forces during water evacuation – consistent with trends in free energies of dehydration across the NU-1000 variants. Water harvesting and hydrolysis of chemical warfare agent simulants were examined to gauge the functional consequences of modification and mechanical stabilization of NU-1000 by Facac ligands. The studies revealed a harvesting capacity of ∼1.1 L of water vapor per gram of Facac-NU-1000 per sorption cycle. They also revealed retention of catalytic MOF activity following 20 water uptake and release cycles. This study provides insights into the basis for node-ligand-engendered stabilization of wide-channel MOFs against collapse during water removal. 

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