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Recently, π–π stacked antiaromatic π‐systems have received considerable attention because they can exhibit stacked‐ring aromaticity due to substantial intermolecular orbital interactions. Here, we report three antiaromatic norcorrole dimers that self‐assemble to form supramolecular architectures through chiral self‐sorting. A 2,2’‐linked norcorrole dimer with 3,5‐di‐tert‐butylphenyl groups forms a π‐stacked dimer both in solid and solution states via homochiral self‐sorting. Its association constant in solution is (3.6±1.7)×105 M−1 at 20 °C. In the solid state, 3,3’‐linked norcorrole dimers with 3,5‐di‐tert‐butylphenyl and phenyl groups afford macrocyclic and helical supramolecular assemblies via heterochiral and homochiral self‐sorting, respectively. Notably, the subtle modification in the substituent resulted in a complete change in the structure of the aggregates and the chiral self‐sorting mode. The present findings demonstrate that structural manipulation in antiaromatic monomer units leads to the formation of various supramolecular assemblies on the basis of the attractive interactions between antiaromatic π‐systems. [ABSTRACT FROM AUTHOR]

Three S‐fused polycyclic aromatic hydrocarbons (PAHs) bearing cyclopenta[b]thiopyran moieties have been designed and successfully synthesized. With the conjugation extension, the absorption onset of the longest PAH reaches 1110 nm. All the three S‐fused PAHs exhibit significant halochromic properties in both solution and solid states. Upon protonation, the proton is incorporated on the cyclopentadiene ring while the positive charge is localized on the thiopyrylium ring. Moreover, no significant difference can be found for the two shorter PAHs upon the protonation by different organic acids, such as trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TfOH), while the longest PAH can be only mono‐protonated by TFA but di‐protonated by stronger TfOH. Furthermore, after protonation, the non‐emissive S‐fused PAHs exhibit strong fluorescence and can be regenerated by simply neutralization with triethylamine. The enhanced emission of mono‐protonated products stem from S2→S0 transitions, which disobey the Kasha's rule. [ABSTRACT FROM AUTHOR]

The effective capture of iodine with high volatility and poisonousness is significant for reprocessing the spent nuclear fuel. In this article, we report a hierarchically porous poly(ionic liquid)‐organic cage composite membrane (PIL@CC3) possessing a gradient content distribution of CC3 cage crystals throughout the membrane to capture iodine vapor. The introduction of microporous CC3 can significantly enhance the uptake capacity of iodine up to 980 mg g−1, which is superior to that of a pristine PIL membrane carrying large meso‐ and macropores (99 mg g−1), and CC3 crystalline powder (662 mg g−1). Such enhanced performance benefits from the micro‐meso‐macroporous structure of the PIL@CC3 membrane in which the large meso‐ and macropores facilitate the mass transfer of iodine molecules from the external environment into the surface of the CC3 crystal, followed by diffusion of iodine molecules from the CC3 surface into the interior and exterior pores of the CC3 crystal. In addition, the asymmetric distribution of CC3 crystals across the PIL@CC3 membrane also displays its advantage in intercepting trace iodine, revealing its great potential for practical application. This study provides an idea for constructing hierarchically porous membrane composites for the removal of toxic vapors. [ABSTRACT FROM AUTHOR]

Axially chiral indole‐based frameworks have been recognized as a class of important five‐membered heterobiaryls and developing catalytic asymmetric approaches for constructing these frameworks in an enantioselective manner is highly desirable. In recent years, synthetic chemists have paid much attention to this research field, and rapid developments have occurred. At this point, a range of axially chiral indole‐based scaffolds have been constructed via various catalytic asymmetric reactions based on different strategies. Thus, the catalytic asymmetric construction of axially chiral indole‐based frameworks has become an emerging area. This minireview summarizes the rapid advances in this field and gives some insights into future developments, which will help this research field to thrive. [ABSTRACT FROM AUTHOR]

The stable deposition of reactive nanostructures on metal electrodes is a key process for modern technologies including energy conversion/ storage, electrocatalysis or sensing. Here a facile, scalable route is reported, which allows the bulk nanostructuring of copper foam electrodes with metal, metal oxide or metal hydroxide nanostructures. A concentration‐gradient driven synthetic approach enables the fabrication of Janus‐type electrodes where one face features Cu(OH)2 nanowires, while the other face features CuO nanoflowers. Thermal or chemical conversion of the nanostructured surfaces into copper oxide or copper metal is possible whilst retaining the respective nanostructure morphologies. As proof of concept, the functionalized electrodes are promising in electrocatalytic water oxidation and water reduction reactions. [ABSTRACT FROM AUTHOR]

The synthesis of antiaromatic NiII–norcorroles having primary, secondary, and tertiary alkyl groups at the reactive meso‐positions was attempted. Reductive coupling of a NiII–dipyrrin precursor provided NiII–meso‐dihexylnorcorrole, which underwent substantial degradation on silica gel. Introduction of tert‐butyl groups was unsuccessful due to the difficult preparation of the corresponding dipyrrin precursor. Meanwhile, NiII–norcorroles with isopropyl and cyclohexyl groups were isolated as stable molecules under ambient conditions. Furthermore, we found that oxidation of NiII–meso‐dialkylnorcorroles with hydrogen peroxide in the presence of sodium carbonate gave NiII–5‐oxaporphyrins(2.0.1.0). In contrast, oxidation of NiII–meso‐dimesitylnorcorrole under the same reaction conditions gave 10‐oxaporphyrin(1.1.1.0). The contrasting reactivity can be attributed to the steric congestion around the meso‐positions. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) for enzyme immobilization have already shown superior tunable and designable characteristics, however, their diverse responsive properties have rarely been exploited. In this work we integrated a responsive MOF into a MOF–enzyme composite with the purpose of designing an "all‐in‐one" multifunctional composite with catalytic and luminescence functions incorporated into a single particle. As a proof‐of‐concept, glucose oxidase (GOx) was encapsulated in situ within an oxygen (O2)‐sensitive, noble‐metal‐free, luminescent CuI triazolate framework (MAF‐2), denoted as GOx@MAF‐2. Owing to the rigid scaffold of MAF‐2 and confinement effect, the GOx@MAF‐2 composite showed significantly improved stability (shelf life of 60 days and heat resistance up to 80 °C) as well as good selectivity and recyclability. More importantly, owing to the O2 sensitivity of MAF‐2, the GOx@MAF‐2 composite exhibited a rapid and reversible response towards dissolved O2, thereby allowing direct and ratiometric sensing of glucose without the need for chromogenic substrates, cascade enzymatic reactions, or electrode systems. High sensitivity with a detection limit of 1.4 μm glucose was achieved, and the glucose levels in human sera were accurately determined. This strategy has led to a new application for MOFs that can be facilely extended to other MOF–enzyme composites due to the multifunctionality of MOFs. Multifunctional composite: The "all‐in‐one" MOF–enzyme composite prepared in this work utilizes MAF‐2 simultaneously as protective matrix and signal transducer and can be applied to the detection of glucose in human serum (see figure). Glucose oxidase (GOx) is encapsulated within the MAF‐2 matrix, and the rapid and reversible response of the latter towards dissolved O2 allows the sensing of glucose. The composite shows good stability, selectivity, and recyclability. [ABSTRACT FROM AUTHOR]

Bimetallic transition-metal oxides, which exhibit superior electrochemical properties compared with pristine single-metal oxides, have recently become a topic of significant research interest for applications in lithium-ion batteries (LIBs). Herein, we report a simple and scalable electrospinning method to synthesize porous CoTiO3 nanofibers as the precursor for nanostructured bimetallic transition-metal oxides formed electrochemically in situ. This strategy ensures uniform mixing and perfect contact between two constituent transition-metal oxides during the lithiation/delithiation process. Furthermore, CoTiO3 nanofibers based on ultrafine CoTiO3 nanocrystals are interconnected to form a nano/microstructured 3D network, which ensures the high stability of the in situ formed structure composed of bimetallic transition-metal oxides, and also fast ion/electron transfer and electrolyte penetration into the electrode. Electrochemical measurements revealed the excellent lithium storage (647 mAh g−1 at 0.1 Ag−1) and retention properties (600 mAh g−1 at 1 Ag−1 after 1200 cycles) of the CoO/TiO2 electrode. Moreover, the electrochemical reaction mechanism was explored by using ex situ X-ray photoelectric spectroscopy and cyclic voltammetry tests, which confirmed the two-phase reaction processes in the electrodes. These results clearly validate the potential of CoTiO3 with a unique nano/microstructured morphology as the precursor for a bimetallic transition-metal oxide for use as the anode material for long-life LIBs. [ABSTRACT FROM AUTHOR]

The design of efficient and stable oxygen evolution reaction (OER) catalysts based on noble‐metal‐free materials is crucial for energy conversion and storage. In this work, it was demonstrated how polyoxometalate (POM)‐doped ZIF‐67 can be converted into a stable oxygen evolution electrocatalyst by chemical etching, cation exchange, and thermal annealing steps. Characterization by X‐ray photoelectron spectroscopy, transmission electron microscopy, energy‐dispersive X‐ray spectroscopy and Raman spectroscopy indicate that POM‐doped ZIF‐67 derived carbon‐supported metal oxides were synthesized. The resulting composite shows structural and compositional advantages which lead to low overpotential (306 mV at j=10 mA ⋅ cm−2) and long‐term stability under harsh OER conditions (1.0 M aqueous KOH). [ABSTRACT FROM AUTHOR]

Keywords: asymmetric catalysis; atropisomer-selectivity; axial chirality; enantioselectivity; indole EN asymmetric catalysis atropisomer-selectivity axial chirality enantioselectivity indole 1 1 1 12/09/20 20201204 NES 201204 B Axially chiral indole-based frameworks b have been recognized as a class of important five-membered heterobiaryls and developing catalytic asymmetric approaches for constructing these frameworks in an enantioselective manner is highly desirable. In recent years, synthetic chemists have paid much attention to this research field, and rapid developments have occurred. Asymmetric catalysis, atropisomer-selectivity, axial chirality, enantioselectivity, indole. [Extracted from the article]

Invited for the cover of this issue are Jie‐Peng Zhang, Zong Dai, and co‐workers at Sun Yat‐sen University. The image depicts the harmonious and synergetic combination of MAF‐2 and glucose oxidase (just like the Tai Chi in the background). Read the full text of the article at 10.1002/chem.201806146. "Since metal–organic frameworks (MOFs) and enzymes both have exhibited diverse functions and properties, we hope this exploratory work will inspire more research on utilizing the multifunctions of MOFs for enzyme‐related applications." Read more about the story behind the cover in the Cover Profile and about the research itself on page 5463 ff. (DOI: 10.1002/chem.201806146). [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) for enzyme immobilization have already shown some superior characteristics; however, their devisable responsive properties have rarely been exploited. This work adopted a facilely synthesized, oxygen‐sensitive luminescent MOF, MAF‐2, for the immobilization of glucose oxidase (GOx) to give GOx@MAF‐2. The MAF‐2 scaffold played both protective and sensing functions in GOx@MAF‐2, which possessed much improved stability and was applied for glucose detection in human sera without any other additional reagents. More information can be found in the Full Paper by J.‐P. Zhang, Z. Dai, et al. on page 5463. [ABSTRACT FROM AUTHOR]

Abstract: A new hexadecahedron assembled by core–shell CoS2 particles@N‐doped carbon (CoS2@NCH) is prepared successfully through the self‐templating method. The CoS2@NCH hybrid electrode delivers a high lithium‐storage capacity of 778 mA h g−1 after 1000 cycles at a high current density of 1 A g−1, which is the longest cycle lifespan among the reported CoS2 anode materials in lithium‐ion batteries. Furthermore, the CoS2@NCH hybrid electrode shows excellent rate capability with a discharge capacity of 220 mA h g−1 at an extremely high current density of 20 A g−1, and a charge capacity of 649 mA h g−1 is restored upon returning the current density back to 2 A g−1. The superior performance is attributed to the unique construction of CoS2@NCH. The N‐doped interconnected porous carbon shells form highly conductive skeletons for quick electron transfer and prevent the electrode from collapsing. Moreover, the porous characteristic of the materials plays a key role: as some effective channels, the mesopores on the porous carbon shells provide greater access for lithium, and the mesopores derived from the particle interspace enables the complete immersion of the electrodes in electrolyte, which alleviates the volume expansion and ensures the integrity of the electrode. In addition, the nanosized CoS2 particles, which shorten the ion‐transport path and provide extra electroactive sites, also improve the reaction kinetics. [ABSTRACT FROM AUTHOR]

In this work, oxygen-deficient anatase TiO2 nanosheets (A-TiO2− xNSs) are proposed as a substrate to improve the electrochemical properties of sulfur electrodes for lithium-sulfur (Li-S) batteries. The A-TiO2− xNSs are prepared by partly reducing pristine TiO2 nanosheets (A-TiO2NSs) in NaBH4 solution. With some oxygen vacancies on the surface of the TiO2 nanosheets, A-TiO2− xNSs not only promote electronic transfer, but also act as more effective polysulfide reservoirs to minimize the dissolution of lithium polysulfides (LiPSs) than the A-TiO2NSs control. Hence, upon utilization as modifiers for cathodes of Li-S batteries, the A-TiO2− xNSs-modified sulfur (A-TiO2− xNSs-S) cathode exhibits a higher reversible specific capacity and greater cycling performance and rate capability than the A-TiO2NSs-modified one (A-TiO2NSs-S). For example, A-TiO2− xNSs-S delivers an initial specific capacity of 1277.1 mAh g−1 at 0.1 C and maintains a stable Coulombic efficiency of approximately 99.2 % after the first five cycles; these values are higher than those of 997.3 mAh g−1 and around 96.7 %, respectively, for A-TiO2NSs-S. The enhanced electrochemical properties of the A-TiO2− xNSs-S cathode can be ascribed mainly to the more effective adsorption of dissolvable and diffused LiPSs by the oxygen vacancies. Therefore, utilization of the structure of oxygen vacancies in Li-S batteries demonstrates great prospects for practical application. [ABSTRACT FROM AUTHOR]