Search

The article presents a study which examines the highly reversible lithium (Li)/dissolved polysulfide cell using a free-standing and self-weaving multi-walled carbon nanotube (MWCNT) paper as an electrode. The study investigates the MWCNT paper by a chemical vapor deposition process. The study reveals that a highly reversible Li/dissolved polysulfide cells were demonstrated as a host electrode.

Light to wear: Aluminum coated fibrous materials with excellent electrical conductivity and mechanical endurance are fabricated at room temperature by a chemical solution process. The resulting aluminum‐coated conductive papers and threads can be used in electric circuits for flexible and wearable electronics. [ABSTRACT FROM AUTHOR]

Making sense: A novel polyacetylene composite material with incorporated aligned carbon nanotubes shows rapid changes in both fluorescent intensity and color appearance in response to applied electric currents, and these electrochromatic transitions remain reversible even after a thousand cycles. The composite material is anticipated to be suitable for various other sensing applications. [ABSTRACT FROM AUTHOR]

Wearable electronics require highly conductive fibrous materials, which can now be fabricated at room temperature. In their Communication on page 7718 ff., H. M. Lee, S. H. Ko, and co‐workers demonstrate that cotton or paper fibers can be impregnated and coated with Al atoms from the precursor Al{O(C4H9)2}. The fibrous materials exhibit excellent electrical conductivity, as well as enduring mechanical strength, which is indicative of their potential applications for flexible and wearable electronics. [ABSTRACT FROM AUTHOR]

This paper discloses the first uses of phosphahelicenes as chiral ligands in transition-metal catalysis. Unlike all known helical phosphines used so far in catalysis, the phosphorus function of phosphahelicenes is embedded in the helical structure itself. This crucial structural feature originates unprecedented catalytic behaviors and efficiency. An appropriate design and fine tuning allowed both high catalytic activity and good enantiomeric excesses to be attained in the gold promoted cycloisomerizations of N-tethered 1,6-enynes and dien-ynes. [ABSTRACT FROM AUTHOR]

The article presents abstracts on papers related to chemistry including "Transition-Metal-Free Catalytic Reduction of Carbon Dioxide," by F. G. Fontaine, M. A. Courtemanche, and M. A. Lègarè, "Effective Cancer Cell Killing by Hydrophobic Nanovoid-Enhanced Cavitation under Safe Low-Energy Ultrasound," by Y. Zhao and colleagues, and "Oxidative Coupling of Organoboron Compounds," by R. N. Dhital and H. Sakurai.

This paper compares rates of charge transport by tunneling across junctions with the structures AgTSX(CH2)2 nCH3 //Ga2O3 /EGaIn ( n=1-8 and X= SCH2 and O2C); here AgTS is template-stripped silver, and EGaIn is the eutectic alloy of gallium and indium. Its objective was to compare the tunneling decay coefficient ( β, Å−1) and the injection current ( J0, A cm−2) of the junctions comprising SAMs of n-alkanethiolates and n-alkanoates. Replacing AgTSSCH2-R with AgTSO2C-R (R=alkyl chains) had no significant influence on J0 (ca. 3×103 A cm−2) or β (0.75-0.79 Å−1)-an indication that such changes (both structural and electronic) in the AgTSXR interface do not influence the rate of charge transport. A comparison of junctions comprising oligo(phenylene)carboxylates and n-alkanoates showed, as expected, that β for aliphatic (0.79 Å−1) and aromatic (0.60 Å−1) SAMs differed significantly. [ABSTRACT FROM AUTHOR]

This paper describes the hydrofluorination of alkenes through sequential H− and F+ addition under palladium catalysis. The reaction is cis specific, thus providing access to benzylic fluorides. The mechanism of this reaction involves an ionic pathway and is distinct from known hydrofluorinations involving radical intermediates. The first catalytic enantioselective hydrofluorination is also disclosed. [ABSTRACT FROM AUTHOR]

A straightforward photo-annealing approach was developed for building functional polymer layers on paper. Conducting polyaniline with the ability for photothermal conversion can be readily annealed by near-infrared light. The annealed polymers become both insulating and hydrophobic. Selective photo-annealing produces a functional layer with patterned conductive arrays. This material exhibits real-time response to ammonium gas. Complete photo-annealing preserves the porous structure but changes the wettability of the polyaniline-nanofiber film. [ABSTRACT FROM AUTHOR]

A photo‐annealing approach was developed for building functional polymer layers on paper. In their Communication on page 4465 ff., Y. Wang and co‐workers show that conducting polyaniline with the ability to undergo photothermal conversion can be annealed by near‐infrared light. The porous structure is retained in the annealed polymer but it becomes insulating and hydrophobic. The asymmetric paper functions as a “water diode” and selective photo‐annealing produces patterned conductive arrays. [ABSTRACT FROM AUTHOR]

Ambient ionization is achieved by spraying from a carbon nanotube (CNT)-impregnated paper surface under the influence of small voltages (≥3 V). Organic molecules give simple high-quality mass spectra without fragmentation in the positive or negative ion modes. Conventional field ionization is ruled out, and it appears that field emission of microdroplets occurs. Microscopic examination of the CNT paper confirms that the nanoscale features at the paper surface are responsible for the high electric fields. Raman spectra imply substantial current flows in the nanotubes. The performance of this analytical method was demonstrated for a range of volatile and nonvolatile compounds and a variety of matrices. [ABSTRACT FROM AUTHOR]

A piece of paper that is impregnated with multi‐walled or single‐walled carbon nanotubes generates ions from diverse analytes at voltages as low as 3 V, as T. Pradeep et al. show in their Communication on page 5936 ff. This miniaturized ion source is held in front of a mass‐spectrometer inlet to collect the mass spectrum. Common pesticides from the surface of an orange, active molecules from tablets, and a variety of analytes, such as amino acids, can been characterized. [ABSTRACT FROM AUTHOR]

The article presents abstracts on papers related to chemistry including "Dihaloimidazolidinediones as Versatile Halodehydrating Agents," by J. P. Moerdyk and C. W. Bielawski, "Rapid and Selective Electrophilic Trifluoromethylation of the 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) Scaffold," by N. Santschi and colleagues, and "Think What Nobody Has Thought," by M. Preuss.

Indolines are important moieties present in various biologically significant molecules and have attracted considerable attention in synthetic chemistry. This paper describes a Heck reaction/CH activation/amination sequence for forming indolines using di-tert-butyldiaziridinone. The reaction process likely proceeds via a pallada(II)cycle, which is converted into an indoline by oxidative addition to the diaziridinone and two subsequent CN bond formations. [ABSTRACT FROM AUTHOR]

When a colloidal drop dries on a surface, most of the particles accumulate at the drop periphery, yielding a characteristic ring-shaped pattern. This so-called coffee-ring effect (CRE) is observed in any pinned evaporating drop containing non-volatile solutes. Here, the CRE is dynamically controlled for the first time by using light, and an unprecedented reconfigurability of the deposit profile is demonstrated. This is achieved through a new mechanism where particle stickiness is optically tuned on demand, thus offering reliable modulation of the deposition pattern. The system consists of anionic nanoparticles and photosensitive cationic surfactants dispersed in water. It is shown that light-dependent modulation of surfactant-particle interactions dictates particle attraction and trapping at the liquid-gas interface, which allows us to direct particle deposition into a wide range of patterns from rings to homogeneous disks. Patterning from single drops is photoreversible upon changing the wavelength whereas spatial control in multiple drop arrays is achieved using a photomask. [ABSTRACT FROM AUTHOR]

The exciton chirality method (ECM) is commonly recognized as one of the best approaches to assign the absolute configuration of biaryls. This paper reports the first exception to this method for a simple biaryl system. ECD and VCD measurements in combination with DFT (B3LYP/6-311G*), TDDFT (CAM-B3LYP/6-311G*), and Coupled-Cluster (RI-SCS-CC2) calculations were used to determine the absolute configurations of axially chiral BODIPY DYEmers. The ECM fails to predict the sign of the intense CD couplet at 500 nm of the 1,1′-coupled dimer. The odd behavior was rationalized by considering the strong transition magnetic dipole associated with the 500 nm transition, which leads to an unexpected dominance of the μm coupling at the expense of the μμ one in these compounds. This is the first case in which a strong μm coupling hampers the use of the ECM, but this behavior should not be restricted to the BODIPY chromophore. [ABSTRACT FROM AUTHOR]

Despite the growth of research in universities on point-of-care (POC) diagnostics for global health, most devices never leave the laboratory. The processes that move diagnostic technology from the laboratory to the field--the processes intended to evaluate operation and performance under realistic conditions--are more complicated than they might seem. Two case studies illustrate this process: the development of a paper-based device to measure liver function, and the development of a device to identify sickle cell disease based on aqueous multiphase systems (AMPS) and differences in the densities of normal and sickled cells. Details of developing these devices provide strategies for forming partnerships, prototyping devices, designing studies, and evaluating POC diagnostics. Technical and procedural lessons drawn from these experiences may be useful to those designing diagnostic tests for developing countries, and more generally, technologies for use in resource-limited environments. [ABSTRACT FROM AUTHOR]

Ligand exchange is central in the processing of inorganic nanocrystals (NCs) and requires understanding of surface chemistry. Studying sterically stabilized HfO2 and ZrO2 NCs using 1H solution NMR and IR spectroscopy as well as elemental analysis, this paper demonstrates the reversible exchange of initial oleic acid ligands for octylamine and self-adsorption of oleic acid at NC surfaces. Both processes are incompatible with an X-type binding motif of carboxylic acids as reported for sulfide and selenide NCs. We argue that this behavior stems from the dissociative adsorption of carboxylic acids at the oxide surface. Both proton and carboxylate moieties must be regarded as X-type ligands yielding a combined X2 binding motif that allows for self-adsorption and exchange for L-type ligands. [ABSTRACT FROM AUTHOR]

The selective radical/radical cross-coupling of two different organic radicals is a great challenge due to the inherent activity of radicals. In this paper, a copper-catalyzed radical/radical C [ABSTRACT FROM AUTHOR]

Lithium diisopropyl amide (LDA) is a very prominent reagent that plays a key role in organic synthesis, serving as a base par excellence for a broad range of deprotonation reactions. However, the state of aggregation in solution in the absence of donor bases was unclear. In this paper we solved this problem by employing DOSY NMR experiments based on a newly elaborated external calibration curve (ECC) approach with normalized diffusion coefficients. [ABSTRACT FROM AUTHOR]

In this paper we report on the influence of light and oxygen on the stability of CH3NH3PbI3 perovskite-based photoactive layers. When exposed to both light and dry air the mp-Al2O3/CH3NH3PbI3 photoactive layers rapidly decompose yielding methylamine, PbI2, and I2 as products. We show that this degradation is initiated by the reaction of superoxide (O2-) with the methylammonium moiety of the perovskite absorber. Fluorescent molecular probe studies indicate that the O2- species is generated by the reaction of photoexcited electrons in the perovskite and molecular oxygen. We show that the yield of O2- generation is significantly reduced when the mp-Al2O3 film is replaced with an mp-TiO2 electron extraction and transport layer. The present findings suggest that replacing the methylammonium component in CH3NH3PbI3 to a species without acid protons could improve tolerance to oxygen and enhance stability. [ABSTRACT FROM AUTHOR]

We report on a paper device capable of carrying out target-induced rolling circle amplification (RCA) to produce massive DNA amplicons that can be easily visualized. Interestingly, we observed that RCA was more proficient on paper than in solution, which we attribute to a significantly higher localized concentration of immobilized DNA. Furthermore, we have successfully engineered a fully functional paper device for sensitive DNA or microRNA detection via printing of all RCA-enabling molecules within a polymeric sugar film formed from pullulan, which was integrated with the paper device. This encapsulation not only stabilizes the entrapped reagents at room temperature but also enables colorimetric bioassays with minimal steps. [ABSTRACT FROM AUTHOR]

Photocatalytic reduction of CO2 to produce fuels is a promising way to reduce CO2 emission and address the energy crisis. However, the H2 evolution reaction competes with CO2 photoreduction, which would lower the overall selectivity for carbonaceous products. Cu2O has emerged as a promising material for suppressing the H2 evolution. However, it suffers from poor stability, which is commonly regarded as the result of the electron-induced reduction of Cu2O. This paper describes a simple strategy using Cu2O as a dark cathode and TiO2 as a photoanode to achieve stable aqueous CO2 reduction with a high Faradaic efficiency of 87.4 % and a selectivity of 92.6 % for carbonaceous products. We have shown that the photogenerated holes, instead of the electrons, primarily account for the instability of Cu2O. Therefore, Cu2O was used as a dark cathode to minimize the adverse effects of holes, by which an improved stability was achieved compared to the Cu2O photocathode under illumination. Additionally, direct exposure of the Cu2O surface to the electrolyte was identified as a critical factor for the high selectivity for carbonaceous products. [ABSTRACT FROM AUTHOR]

In a recent paper, Wang et al. found an iridium-containing compound with a formal oxidation state of 9. This is the highest oxidation state ever found in a stable compound. To learn if this is the highest chemical oxidation state possible, Kohn-Sham density functional theory was used to study various compounds, including PdO42+, PtO42+, PtO3F22+, PtO4OH+, PtO5, and PtO4SH+, in which the metal has an oxidation state of 10. It was found that PtO42+ has a metastable state that is kinetically stable with a barrier height for decomposition of 31 kcal mol−1 and a calculated lifetime of 0.9 years. All other compounds studied would readily decompose to lower oxidation states. [ABSTRACT FROM AUTHOR]

Efficient charge separation and light absorption are crucial for solar energy conversion over solid photocatalysts. This paper describes the construction of Pt@TiO2@In2O3@MnO x mesoporous hollow spheres (PTIM-MSs) for highly efficient photocatalytic oxidation. TiO2-In2O3 double-layered shells were selectively decorated with Pt nanoparticles and MnO x on the inner and outer surfaces, respectively. The spatially separated cocatalysts drive electrons and holes near the surface to flow in opposite directions, while the thin heterogeneous shell separates the charges generated in the bulk phase. The synergy between the thin heterojunctions and the spatially separated cocatalysts can simultaneously reduce bulk and surface/subsurface recombination. In2O3 also serves as a sensitizer to enhance light absorption. The PTIM-MSs exhibit high photocatalytic activity for both water and alcohol oxidation. [ABSTRACT FROM AUTHOR]

The article talks about Jun Chen, Professor and Cheung Kong Scholar of Chemistry at Nankai University, Tianjin.His education and the awards won by him are mentioned. His views on his favorite food and scientists and songs and motivation and his top 5 research papers in the field of chemistry are also mentioned.

Biomolecular transport systems based on cytoskeletal filaments and motor proteins have become promising tools for a wide range of nanotechnological applications. In this paper, we report control of such transport systems using substrates with switchable shape. We demonstrate this approach on the example of microtubules gliding on surfaces of self-folding polymer bilayers with adsorbed kinesin motors. The polymer bilayers are able to undergo reversible transitions between flat and tube-like shapes that allow the externally controlled retention and release of gliding microtubules. The demonstrated approach, based on surfaces with reconfigurable topography, opens broad perspectives to control biomolecular transport systems for bioanalytical and sensing applications, as well as for the construction of subcellular compartments in the field of synthetic biology. [ABSTRACT FROM AUTHOR]

The article reflects on author Karsten Meyer who discusses the discovery of penicillin by scientist Alexander Fleming as the most significant historic event of the past 100 years, study of chemistry, and uranium as his favorite molecule. He also mentions research in chemistry and how to publish high-quality research papers.

We introduce a general method to transform antibodies into ratiometric, bioluminescent sensor proteins for the no-wash quantification of analytes. Our approach is based on the genetic fusion of antibody fragments to NanoLuc luciferase and SNAP-tag, the latter being labeled with a synthetic fluorescent competitor of the antigen. Binding of the antigen, here synthetic drugs, by the sensor displaces the tethered fluorescent competitor from the antibody and disrupts bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. The semisynthetic sensors display a tunable response range (submicromolar to submillimolar) and large dynamic range (Δ Rmax>500 %), and they permit the quantification of analytes through spotting of the samples onto paper followed by analysis with a digital camera. [ABSTRACT FROM AUTHOR]

The first oxidative C(sp3)−H/C(sp3)−H cross-dehydrogenative coupling (CDC) reaction promoted by an internal oxidant is reported. This copper-catalyzed CDC reaction of oxime acetates and trifluoromethyl ketones provides a simple and efficient approach towards 2-trifluoromethyldihydropyrrol-2-ol derivatives in a highly diastereoselective manner by cascade C(sp3)−C(sp3) bond formation and cyclization. These products were further transformed into various significant and useful trifluoromethylated heterocyclic compounds, such as trifluoromethylated furan, thiophene, pyrrole, dihydropyridazine, and pyridazine derivatives. A trifluoromethylated analogue of an Aβ42 lowering agent was also synthesized smoothly. Preliminary mechanistic studies indicated that this reaction involves a copper(I)/copper(III) catalytic cycle with the oxime acetate acting as an internal oxidant. [ABSTRACT FROM AUTHOR]

Abstract: We report a paper‐based aptasensor platform that uses two reaction zones and a connecting bridge along with printed multifunctional bio/nano materials to achieve molecular recognition and signal amplification. Upon addition of analyte to the first zone, a fluorescently labelled DNA or RNA aptamer is desorbed from printed graphene oxide, rapidly producing an initial fluorescence signal. The released aptamer then flows to the second zone where it reacts with printed reagents to initiate rolling circle amplification, generating DNA amplicons containing a peroxidase‐mimicking DNAzyme, which produces a colorimetric readout that can be read in an equipment‐free manner or with a smartphone. The sensor was demonstrated using an RNA aptamer for adenosine triphosphate (a bacterial marker) and a DNA aptamer for glutamate dehydrogenase (Clostridium difficile marker) with excellent sensitivity and specificity. These targets could be detected in spiked serum or feacal samples, demonstrating the potential for testing clinical samples. [ABSTRACT FROM AUTHOR]

Abstract: Supported vanadium oxides are one of the most promising alternative catalysts for propane dehydrogenation (PDH) and efforts have been made to improve its catalytic performance. However, unlike Pt‐based catalysts, the nature of the active site and surface structure of the supported vanadium catalysts under reductive reaction conditions still remain elusive. This paper describes the surface structure and the important role of surface‐bound hydroxyl groups on VOx / γ‐Al2O3 catalysts under reaction conditions employing in situ DRIFTS experiments and DFT calculations. It is shown that hydroxyl groups on the VOx /Al2O3 catalyst (V−OH) are produced under H2 pre‐reduction, and the catalytic performance for PDH is closely connected to the concentration of V−OH species on the catalyst. The hydroxyl groups are found to improve the catalyst that leads to better stability by suppressing the coke deposition. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical reduction of carbon dioxide (CO2) into value‐added chemicals is a promising strategy to reduce CO2 emission and mitigate climate change. One of the most serious problems in electrocatalytic CO2 reduction (CO2R) is the low solubility of CO2 in an aqueous electrolyte, which significantly limits the cathodic reaction rate. This paper proposes a facile method of catholyte‐free electrocatalytic CO2 reduction to avoid the solubility limitation using commercial tin nanoparticles as a cathode catalyst. Interestingly, as the reaction temperature rises from 303 K to 363 K, the partial current density (PCD) of formate improves more than two times with 52.9 mA cm−2, despite the decrease in CO2 solubility. Furthermore, a significantly high formate concentration of 41.5 g L−1 is obtained as a one‐path product at 343 K with high PCD (51.7 mA cm−2) and high Faradaic efficiency (93.3 %) via continuous operation in a full flow cell at a low cell voltage of 2.2 V. [ABSTRACT FROM AUTHOR]

The nature of the processes at the origin of life that selected specific classes of molecules for broad incorporation into cells is controversial. Among those classes selected were polyisoprenoids and their derivatives. This paper tests the hypothesis that polyisoprenoids were early contributors to membranes in part because they (or their derivatives) could facilitate charge transport by quantum tunneling. It measures charge transport across self‐assembled monolayers (SAMs) of carboxyl‐terminated monoterpenoids (O2C(C9HX)) and alkanoates (O2C(C7HX)) with different degrees of unsaturation, supported on silver (AgTS) bottom electrodes, with Ga2O3/EGaIn top electrodes. Measurements of current density of SAMs of linear length‐matched hydrocarbons—both saturated and unsaturated—show that completely unsaturated molecules transport charge faster than those that are completely saturated by approximately a factor of ten. This increase in relative rates of charge transport correlates with the number of carbon–carbon double bonds, but not with the extent of conjugation. These results suggest that polyisoprenoids—even fully unsaturated—are not sufficiently good tunneling conductors for their conductivity to have favored them as building blocks in the prebiotic world. [ABSTRACT FROM AUTHOR]

Reported here is the first highly selective conversion of various waste plastics into C2 fuels under simulated natural environment conditions by a sequential photoinduced C−C cleavage and coupling pathway, where single‐use bags, disposable food containers, food wrap films, and their main components of polyethylene, polypropylene, and polyvinyl chloride can be photocatalytically transformed into CH3COOH without using sacrificial agents. As an example, polyethylene is photodegraded 100 % into CO2 within 40 h by single‐unit‐cell thick Nb2O5 layers, while the produced CO2 is further photoreduced to CH3COOH. Various methods and experiments disclose that O2 and.OH radicals trigger the oxidative C−C cleavage of polyethylene to form CO2, while other investigations show that the yielded CH3COOH stems from CO2 photoreduction by C−C coupling of.COOH intermediates. This two‐step plastic‐to‐fuel conversion may help to simultaneously address the white pollution crisis and harvest highly valuable multicarbon fuels in natural environments. [ABSTRACT FROM AUTHOR]

This paper describes a new method for the transannular functionalization of the γ‐C−H bonds in alicyclic amines to install C(sp3)−halogen, oxygen, nitrogen, boron, and sulfur bonds. The key challenge for this transformation is controlling the relative rate of Cγ−H versus Cα−H functionalization. We demonstrate that this selectivity can be achieved by pre‐complexation of the substrate with Pd prior to the addition of oxidant. This approach enables the use of diverse oxidants that ultimately install various heteroatom functional groups at the γ‐position with high site‐ and diastereoselectivity. [ABSTRACT FROM AUTHOR]

Atropisomers, biaryls, cycloaddition, organocatalysis, axial chirality Keywords: atropisomers; axial chirality; biaryls; cycloaddition; organocatalysis EN atropisomers axial chirality biaryls cycloaddition organocatalysis 17248 17248 1 07/28/21 20210802 NES 210802 The authors of this Communication have inadvertently overlooked a previous work by Professor Ryo Irie and co-workers, in which they reported one case study using a similar catalytic system.[1] This reference should have been cited in the paper. The authors apologize for omitting this relevant work and all authors are grateful to the kind readers for raising this point to their attention. [Extracted from the article]

As a typical class of man‐made nanoreactors, metal‐loaded hollow carbon nanostructures (MHC nanoreactors) exhibit competitive potentials in the heterogeneous catalysis due to their tailorable microenvironment effects, in which the void‐confinement effect is one of the most fundamental functions in boosting the catalytic performance. Herein this paper, Ru‐loaded hollow carbon spheres are employed as nanoreactors with a crucial biomass hydrogenation process, levulinic acid (LA) hydrogenation into γ‐valerolactone, as the probe reaction to further recognize the forming mechanism of this pivotal effect. We demonstrated that the void‐confinement effect of the selected MHC nanoreactors is essentially driven by an integrating action of electronic metal‐support interaction, reactant enrichment and diffusion, which are mainly ascribed to peculiar properties of hollow nanoreactors both in electronic and structural aspects, respectively. This work offers a distinct case for interpreting the catalytic behaviour of MHC nanoreactors, which could potentially promise broader insights into the microenvironment engineering strategies of hollow nanostructures. [ABSTRACT FROM AUTHOR]

Force‐selective mechanochemical reactions may be important for applications in polymer mechanochemistry, yet it is difficult to achieve such reactions. This paper reports that cis‐N‐phthalimidoaziridine incorporated into a macromolecular backbone undergoes migration of N‐phthalimido group to afford imine under mechanochemical condition and not thermal one. The imine is further hydrolyzed by water bifurcating into amine and aldehyde. These structural transformations are confirmed by 1H NMR and FT‐IR spectroscopic analyses. Computational simulations are conducted for the aziridine mechanophore to propose the mechanism of reaction and define the substrate scope of reaction. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks provide versatile templates for the fabrication of various metal/carbon materials, but most of the derived composites possess only microspores, limiting the accessibility of embedded active sites. Herein, we report the construction of cobalt/nitrogen‐doped carbon composites with a three‐dimensional (3D) ordered macroporous and hollow‐wall structure (H‐3DOM‐Co/NC) using a single‐crystal ordered macropore (SOM)‐ZIF‐8@ZIF‐67 as precursor. During the pyrolysis, the interconnected macroporous structure of SOM‐ZIF‐8@ZIF‐67 is mostly preserved, whereas the pore wall achieves a solid‐to‐hollow transformation with Co nanoparticles formed in the hollow walls. The 3D‐ordered macroporous carbon skeleton may effectively promote long‐range mass transfer and the hollow wall can facilitate local accessibility of active sites. This unique structure can greatly boost its catalytic activity in the selective hydrogenation of biomass‐derived furfural to cyclopentanol, much superior to its counterparts without this well‐designed hierarchically porous structure. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of NO not only offers an attractive alternative to the Haber–Bosch process for ambient NH3 production but mitigates the human‐caused unbalance of nitrogen cycle. Herein, we report that MoS2 nanosheet on graphite felt (MoS2/GF) acts as an efficient and robust 3D electrocatalyst for NO‐to‐NH3 conversion. In acidic electrolyte, such MoS2/GF attains a maximal Faradaic efficiency of 76.6 % and a large NH3 yield of up to 99.6 μmol cm−2 h−1. Using MoS2 nanosheet‐loaded carbon paper as the cathode, a proof‐of‐concept device of Zn‐NO battery was assembled to deliver a discharge power density of 1.04 mW cm−2 and an NH3 yield of 411.8 μg h−1 mgcat.−1. Calculations reveal that the positively charged Mo‐edge sites facilitate NO adsorption/activation via an acceptance–donation mechanism and disfavor the binding of protons and the coupling of N−N bond. [ABSTRACT FROM AUTHOR]

Electrochemical redox‐control is an emerging strategy for the regulation of polymerization process without the addition of external oxidants and reductants, which enables the control over composition, microstructure and properties of the polymer products. In this paper, based on the chemical selectivity of heterometallic Salen‐Co‐Mn complexes of different valences, an electrochemically switchable strategy was developed for the copolymerization of lactide (LA), CO2 and epoxides. The switchable redox reactions endowed this system with the capability to easily synthesize a multi‐block copolymer of polylactide (PLA) and polycarbonate (PC). Moreover, the multi‐block copolymer could be further modified by introducing various monomers with different microstructures and functional groups. [ABSTRACT FROM AUTHOR]

Long‐lived afterglow room‐temperature phosphorescence (RTP) from natural phenolics has seldom been reported yet this is essential for the development of sustainable afterglow RTP materials. With this research, we have prepared sustainable afterglow RTP materials (GA@SA) with a lifetime of up to ≈934.7 ms by embedding gallic acid (GA) within a Ca2+‐crosslinked sodium alginate (SA) matrix. Theoretical simulations indicate that the restricted carbonyl moieties of the GA and H‐type aggregates of GA in a SA matrix promoted the spin orbit coupling (SOC) of GA and induced afterglow emission. Moreover, afterglow RTP emission could be produced by embedding different types of natural phenolics such as, tannic acid, caffeic acid and chlorogenic acid into Ca2+‐crosslinked networks of SA. As an illustration of potential applications, GA@SA was used to prepare anti‐counterfeit afterglow clothing and paper. This work provides an innovative method for the activation of long‐lived afterglow RTP from sustainable phenolics. [ABSTRACT FROM AUTHOR]

Porous organic polymer films (PFs) with intrinsical porosity and tuneable pore environment are ideally suited for application in electronic devices. However, the huge challenges still exist for construction of electronic devices based on PFs owing to lack of robustness, processability, and controllable preparation. Herein, we report the electrochemical preparation of carbazole‐based porous organic polymer films (eCPFs) as switchable materials for the memristors. These eCPFs possess the characteristics of controllable thickness/size, high stability, and excellent porosity. Carbazole and cyano groups are introduced into the eCPFs to constructing electron transfer systems. Thus, the memristors constructed based on these eCPFs exhibit excellent switching performance, reliability, and reproducibility. The electrochemically controllable preparation method of porous organic polymer membranes proposed in this paper provides a feasible idea for the developments of electronic devices. [ABSTRACT FROM AUTHOR]

Improving the stability of sensitive catalytic systems is an emerging research topic in the catalysis field. However, the current design of heterogeneous catalysts mainly improves their catalytic performance. This paper presents a single‐atom catalyst (SAC) strategy to improve the cobalt‐catalysed fluorination of acyl chlorides. A stable Co−F intermediate can be formed through the oxidative fluorination of Co1−N4@NC SAC, which can replace the unstable high‐valent cobalt catalytic system and avoid the use of phosphine ligands. In the SAC system, KF can be employed as a fluorinating reagent to replace the AgF, which can be applied to various substrates and scale‐up conversion with high turnover numbers (TON=1.58×106). This work also shows that inorganic SACs have tremendous potential for organofluorine chemistry, and it provides a good reference for follow‐up studies on the structure‐activity relationship between catalyst design and chemical reaction mechanisms. [ABSTRACT FROM AUTHOR]

The development of novel metal organic framework (MOF) friction power generation materials with high stability is important. This paper reports the first example of a double‐helix metal chain organic framework with a network structure (ZUT‐8). ZUT‐8 shows high chemical stability, functional adjustability, and excellent output performance of friction power generation, which is superior to traditional coordination polymer materials. The cathodic protection system with ZUT‐8 can prevent metal corrosion significantly. The output performance can be improved effectively by enhancing the conjugate effect of the linker. The theoretical calculation results showed that an increase in the degree of conjugation could significantly reduce the band gap, thereby affecting the friction power output signal. This study opens the door to constructing MOF materials with a double‐helix metal chain and will promote their potential applications in self‐powered electrochemical cathodic protection. [ABSTRACT FROM AUTHOR]

Our teams benefit tremendously from a legacy of collaboration between TRIUMF, the University of Copenhagen and the University of British Columbia, and from a broad, supportive community of inspiring researchers. " I My favorite thing about my lab group is that we all are just ordinary people who are doing things together in an extraordinary way ... The most important thing I have learned from my students is to stay open-minded, not to be afraid of unconventional approaches, and always celebrate victories, no matter how small or big they are ... i " Find out more about Monika Stachura in her Introducing ... Profile. Our paper is the culmination of five years of pioneering work in establishing a novel way of performing NMR experiments with radioactive ions instead of stable isotopes. [Extracted from the article]

The concept of green carbon science is to promote the goal of achieving carbon neutrality, the importance and urgency of which have been well‐recognized and received worldwide attention. Carbon neutrality has become the focus of research work in many fields, and correspondingly, a growing number of papers and publications have been published over the last few years. However, since carbon neutralization is a real problem that urgently requires technical solutions, the transition from fundamental research to practical applications must be accelerated. A number of research teams are bold in putting things into practice and blazing new trails. This Review summarizes the recent technological developments within the framework of green carbon science, focusing on conducted pilot tests, industrial demonstrations, and commercial applications beyond the laboratory stage. [ABSTRACT FROM AUTHOR]

We report herein an asymmetric Pictet–Spengler reaction of α‐ketoesters. In the presence of a catalytic amount of simple alanine‐derived squaramide and p‐nitrobenzoic acid, reaction of tryptamines with methyl 2‐oxoalkanoates afforded the corresponding 1‐alkyl‐1‐methoxycarbonyl tetrahydro‐β‐carbolines (THBCs) in high yields and ee values. A primary kinetic isotope effect (KIE=4.5) using C2‐deteurium‐labelled tryptamine indicates that rearomatization through deprotonation of the pentahydro‐β‐carbolinium ion could be the rate‐ and enantioselectivity‐determining step. A concise enantioselective total synthesis of (+)‐alstratine A, a hexacyclic cagelike monoterpene indole alkaloid, featuring this reaction as a key step, was subsequently accomplished. Remeasurement of the [a]D value of the natural product indicates that natural alstratine A is dextrorotatory rather than levorotatory as it was initially reported in the isolation paper. [ABSTRACT FROM AUTHOR]