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Two new metallocycle‐supported POM‐based metal‐organic frameworks were isolated by employing isomeric N‐riched rigid organic ligands (straight and the V‐shaped). It is Interesting that both modes can form metallocycles with Ag⁺ cations and further to incorporate POMs. Obtained compounds could fast and selectively separate MB⁺ dye molecules from the mixtures of MB⁺/RhB⁺ and MB⁺/MO– for a moment, respectively.

Two novel POM‐based metal‐organic frameworks, [Ag₇(L₁)₂ ·(µ₂‐OH)₄][H₃VW₁₂O₄₀] (1) and [Ag₈(L₂)₄][VW₁₂O₄₀]·4H₂O (2) have been isolated by altering the isomeric organic ligands {5‐[n‐(1,2,4‐triazol‐4‐yl)phenyl]‐1H‐tetrazole: n = 3 (HL₁); n = 4 (HL₂)} under hydrothermal conditions. Due to L₁ acts as a V‐shaped linker, compound 1 displays a 3D MOF with three types of metallocycles, in which the Keggin polyanions locat in the largest metallocycle (the size of void ca. 13.31 Å × 13.53 Å). However, when the ligand is replaced by straight ligand L₂, compound 2 with a different structure is obtained. Although compound 2 is also a 3D MOF, the types of metallocycle are reduced to one. The Keggin polyanions are seated in the only metallocycle (the size of void ca. 13.6 Å × 13.7 Å). In addition, the adsorption behaviors of the title compounds for organic dyes were investigated in detail. In particular, compound 1 could selectively separate MB⁺ from the mixture of MB⁺/RhB⁺ and MB⁺/MO^– within 5 min, which can be used as a chromatography column for dyes removal.

“My favorite motto is be good, be happy, be motivated. My biggest motivation is to overcome challenges …” Find out more about Xiao‐Feng Wu in his Author Profile.

Textbook answer! A sustainable and generalized route for production of amides (up to 21 examples) is developed from selective aerobic oxidations of amines over a non‐noble MnO_x nanorod catalyst. More importantly, this catalyst is leaching‐free, stable, and reusable, outperforming the state‐of‐the‐art heterogeneous catalysts such as Ru(OH)_x/Al₂O₃.

Abstract

The development of heterogeneous catalysts for the synthesis of pharmaceutically relevant compounds is always important for chemistry research. Here, we report a selective aerobic oxidation of aromatic and aliphatic amines to corresponding amides over a nanorod manganese oxide (NR‐MnO_x) catalyst. The kinetic studies reveal that the NR‐MnO_x catalyzed amine‐to‐amide reaction proceeds the oxidative dehydrogenation of the amines into nitriles, followed by hydrolysis of nitrile into amides. The NR−MnO_x exhibits fast kinetics and high selectivities in these steps, as well as hinders the by‐product formation. More importantly, the NR‐MnO_x catalyst is stable and reusable in the continuous recycle tests with water as a sole by‐product, exhibiting superior sustainability and significant advancement to outperform the traditional amide production route in acidic or basic media with toxic by‐products.

Keep on POPping! Porous organic polymers (POPs) with high surface area, chemical stability, nanoscale porosity and structural diversity have huge potential as selective CO₂ adsorbent and catalysis for the CO₂ fixation reactions. This review provides a brief account in designing POPs and their application in CO₂ adsorption and fixation for the synthesis of fuels and value added fine chemicals.

Abstract

To overcome the challenges of global warming and environmental pollution it is mandatory to reduce the concentration of atmospheric carbon dioxide (CO₂), which is largely accumulated in air through the combustion of fossil fuels. Thus, sequestration of CO₂ through physisorption on solid adsorbents and their successful conversion into value added fine chemicals are the major priority areas of research today. Innovation of efficient solid CO₂‐philic adsorbents together with their high mechanical/chemical stability and regeneration efficiency are the most challenging objectives to achieve this goal. In this context, porous organic polymers (POPs) owing to their high specific surface area, chemical stability, nanoscale porosity and structural diversity have huge potential to play as selective CO₂ adsorbent. POPs synthesized through large varieties of reactive monomers via simple and convenient chemical routes can be the ideal adsorbents for the CO₂ storage and fixation reactions. A wide range of POPs can be synthesized from different multidentate amines, aldehydes, carboxylic acids or triazine monomers through the polycondensation reactions or solid state condensation reactions. Ease of synthesis, uniform pore width together with high surface area and surface basic sites (nitrogen and other heteroelements) play crucial role in the CO₂ absorption and conversion reactions. This review provides a concise account in designing POPs and their application in CO₂ adsorption and fixation into reactive organic molecules for the synthesis of fuels and value added fine chemicals.

Alarming trend: High resolution mass spectrometry revealed hundreds of previously unknown halogenated contaminants in polar bear serum. A mouse study confirmed the 5 new PCB metabolite classes. Stable time‐trends of PCB metabolites and increasing fluoroalkyl contaminants in polar bear serum between the mid‐1980s and 2016 make toxicological studies on these new contaminants warranted.

Abstract

Exposure of polar bears (Ursus maritimus) to persistent organic pollutants was discovered in the 1970s, but recent evidence suggests the presence of unknown toxic chemicals in their blood. Protein and phospholipid depleted serum was stirred with polyethersulfone capillaries to extract a broad range of analytes, and nontarget mass spectrometry with “fragmentation flagging” was used for detection. Hundreds of analytes were discovered belonging to 13 classes, including novel polychlorinated biphenyl (PCB) metabolites and many fluorinated or chlorinated substances not previously detected. All analytes were detected in the oldest (mid‐1980s) archived polar bear serum from Hudson Bay and Beaufort Sea, and all fluorinated classes showed increasing trends. A mouse experiment confirmed the novel PCB metabolites, suggesting that these could be widespread in mammals. Historical exposure and toxic risk has been underestimated, and these halogenated contaminants pose uncertain risks to this threatened species.