• Issue

    Angewandte Chemie International Edition: Volume 60, Issue 48

    25165-25582
    November 22, 2021

Cover Pictures

Free Access

Cover Picture: Conversion of Ammonia to Hydrazine Induced by High-Frequency Ultrasound (Angew. Chem. Int. Ed. 48/2021)

  • Pages: 25165
  • First Published: 14 October 2021
Description unavailable

Ammonia has been converted into hydrazine, a chemical of utmost importance for organic synthesis and energy purposes. In their Communication on page 25230, François Jérôme et al. report that cavitation bubbles, created by ultrasonic irradiation of aqueous ammonia at a high frequency, act as microreactors to activate and convert ammonia into hydrazine at the gas–liquid interface. Maintaining the aqueous solution close to 30 °C prevents the degradation of in situ produced hydrazine.

Free Access

Inside Cover: Local Ordering of Molten Salts at NiO Crystal Interfaces Promotes High-Index Faceting (Angew. Chem. Int. Ed. 48/2021)

  • Pages: 25166
  • First Published: 14 September 2021
Description unavailable

High-index NiO faceting during molten salt synthesis is investigated with density functional theory by Jeffrey D. Rimer, Matteo Maestri, and co-workers in their Research Article on page 25391. Trapezohedral NiO particles observed in experiments are shown to form in LiCl and KCl due to locally ordered alkali chloride structures, which act as capping agents during crystal growth. In the absence of salt, octahedral NiO particles are produced because of their stable hydroxylated surfaces.

Free Access

Inside Back Cover: Radically Enhanced Dual Recognition (Angew. Chem. Int. Ed. 48/2021)

  • Pages: 25583
  • First Published: 14 October 2021
Description unavailable

Selective recognition of two stacked viologen radical cations in solution using a size-matched radical host is reported by J. Fraser Stoddart and co-workers in their Research Article on page 25454. By employing 2,6-bismethylenenaphthalene as the linker, the bisradical dicationic host is able to accommodate two methyl viologen radical cation guests with strong and cooperative binding.

Free Access

Back Cover: Proton Traffic Jam: Effect of Nanoconfinement and Acid Concentration on Proton Hopping Mechanism (Angew. Chem. Int. Ed. 48/2021)

  • Pages: 25584
  • First Published: 03 September 2021
Description unavailable

Protons confined within nonionic reverse micelles experience a “traffic jam” in which forward proton hopping, or the Grotthuss mechanism, is restricted. This effect is size- and concentration-dependent: Protons in small micelles or at lower concentrations diffuse freely via forward hopping. For larger sizes or higher concentrations, ions accumulate at the interfacial region of the micelle, causing a gridlock that decreases available pathways for movement of protons to the water interior, as reported by Martina Havenith, Teresa Head-Gordon, and co-workers in their Research Article on page 25419.

Frontispiece

Free Access

Frontispiece: On-Surface Synthesis and Collective Spin Excitations of a Triangulene-Based Nanostar

  • First Published: 15 November 2021
Description unavailable

Macrocycles In their Communication on page 25224, Thomas Frederiksen, Jose Ignacio Pascual, Diego Peña et al. report the on-surface synthesis and collective spin excitations of a triangulene-based nanostar.

Free Access

Frontispiece: A Titanium Nitride Nanozyme for pH-Responsive and Irradiation-Enhanced Cascade-Catalytic Tumor Therapy

  • First Published: 15 November 2021
Description unavailable

Nanozymes In their Research Article on page 25328, Xin Yu, Jing Liu, Chunying Chen et al. report a titanium nitride nanozyme for pH-responsive and irradiation-enhanced cascade-catalytic tumor therapy.

Graphical Abstract

Free Access

Graphical Abstract: Angew. Chem. Int. Ed. 48/2021

  • Pages: 25169-25184
  • First Published: 15 November 2021

Corrigendum

Introducing …

Free Access

Shelley Claridge

  • Pages: 25186
  • First Published: 25 October 2021
Description unavailable

My favorite equation is the equation for Gibbs free energy. It tells us that things happen for a good reason … I can never resist going back as far as I can through the literature to understand where an idea first started …” Find out more about Shelley Claridge in her Introducing … Profile.

Minireviews

N-Heterocycle Synthesis

Open Access

Synthesis of N-Heterocycles via Oxidant-Free Dehydrocyclization of Alcohols Using Heterogeneous Catalysts

  • Pages: 25188-25202
  • First Published: 17 June 2021
Description unavailable

This Minireview summarizes recent developments in which both noble and non-noble metal-based heterogeneous catalysts are used to synthesize N-heterocycles from alcohols and N-nucleophiles via acceptorless dehydrogenation or borrowing hydrogen methodologies. The strategies for the preparation and functionalization of heterogeneous catalysts, reaction mechanisms, and the roles of heterogeneous catalysts in these reactions are also discussed.

Reviews

Structure Analysis

Crystalline Sponge Method: X-ray Structure Analysis of Small Molecules by Post-Orientation within Porous Crystals—Principle and Proof-of-Concept Studies

  • Pages: 25204-25222
  • First Published: 09 June 2021
Description unavailable

Crystal growth is not needed for single-crystal X-ray structure analysis when the crystalline sponge method is used. This method makes use of single-crystalline porous coordination networks (“crystalline sponges”) that can absorb small guest molecules within the pores and make the absorbed guests observable by conventional single-crystal diffraction. This Review focuses on the principles of this approach as well as proof-of-concept studies.

Communications

On-Surface Synthesis | Very Important Paper

Open Access

On-Surface Synthesis and Collective Spin Excitations of a Triangulene-Based Nanostar

  • Pages: 25224-25229
  • First Published: 13 October 2021
Description unavailable

A star-shaped triangulene cyclic hexamer, which accumulates 12 unpaired electrons, was prepared by combining solution chemistry and on-surface synthesis. The resulting triangulene-based nanostar was visualized by bond-resolved scanning tunneling microscopy on a gold substrate. The collective spin excitations, explained by the Heisenberg model, were revealed by inelastic electron tunneling spectroscopy.

Sonochemistry | Hot Paper

Conversion of Ammonia to Hydrazine Induced by High-Frequency Ultrasound

  • Pages: 25230-25234
  • First Published: 27 August 2021
Description unavailable

Cavitation bubbles act as microreactors to activate NH3, resulting in the formation of NH species that further recombine to hydrazine at the bubble–liquid interface. One of the advantages of this technology is the compartmentation of the as-formed hydrazine in the bulk solution, maintained at only 30 °C, which limits its thermal degradation.

Photocatalysis

Visible-Light Induced C(sp2)−H Amidation with an Aryl–Alkyl σ-Bond Relocation via Redox-Neutral Radical–Polar Crossover

  • Pages: 25235-25240
  • First Published: 23 September 2021
Description unavailable

Herein, a photocatalyzed, intramolecular C(sp2)−H amidation of N-benzoyloxyamides has been developed to afford δ-benzolactams with an aryl-alkyl σ-bond relocation. Upon the formation of amidyl radical via reductive N−O bond cleavage, selective radical ipso-addition followed by a redox-neutral radical–polar crossover was suggested to be responsible for the preferential C−C bond migration.

CO2 Reduction

Atomically Dispersed s-Block Magnesium Sites for Electroreduction of CO2 to CO

  • Pages: 25241-25245
  • First Published: 22 September 2021
Description unavailable

Atomically dispersed magnesium atoms embedded in graphitized C3N4 (Mg-C3N4) show weak CO adsorption because of nondirectionally delocalized Mg 3 s orbit. Mg-C3N4 exhibits a high turnover frequency (TOF) of ≈18 000 hour−1 under a CO Faradaic efficiency ≥90 %. Furthermore, the flow cell fabricated with Mg-C3N4 reaches a large current density of −300 mA cm−2 under a CO Faradaic efficiency ≥90 %.

Aggregation-Induced Emission | Hot Paper

Core–Shell Fluorescent Polymeric Particles with Tunable White Light Emission Based on Aggregation Microenvironment Manipulation

  • Pages: 25246-25251
  • First Published: 24 September 2021
Description unavailable

Core–shell fluorescent polymeric particles (CS-FPPs) were constructed based on aggregation-induced emission (AIE) via the stepwise self-stabilized precipitation (2SP) polymerization, and white light emission of CS-FPPs was achieved with the CIE1931 coordinate of (0.33, 0.34), which could be simply but effectively tuned by manipulating the aggregation microenvironment of the AIEgens.

Photoredox Catalysis

Open Access

Cooperative NHC/Photoredox Catalyzed Ring-Opening of Aryl Cyclopropanes to 1-Aroyloxylated-3-Acylated Alkanes

  • Pages: 25252-25257
  • First Published: 28 September 2021
Description unavailable

Ring-opening/arylcarboxylation/acylation of mono, di and trisubstituted cyclopropanes enabled by cooperative NHC and organophotoredox catalysis for the preparation of γ-aroyloxy ketones is reported. Key step is the radical/radical cross- coupling of a benzylic radical generated in the photoredox catalysis cycle and a ketyl radical formed in the NHC catalysis cycle.

Rearrangements | Hot Paper

Open Access

Gold-Catalyzed Reaction of Propargyl Esters and Alkynylsilanes: Synthesis of Vinylallene Derivatives through a Twofold 1,2-Rearrangement

  • Pages: 25258-25262
  • First Published: 28 September 2021
Description unavailable

An efficient synthesis of structurally complex allenylsilanes through gold-catalyzed coupling of propargyl esters with alkynylsilanes is described. DFT calculations support a stepwise pathway consisting of two 1,2-rearrangements (acyloxy and silyl). A preliminary study on the enantioselective version would demonstrate its feasibility (er up to 95:5).

Electrocatalysis

High-Performance Electrochemical NO Reduction into NH3 by MoS2 Nanosheet

  • Pages: 25263-25268
  • First Published: 14 September 2021
Description unavailable

MoS2/GF behaves as a superb and durable electrocatalyst for ambient NH3 generation via NO reduction in acids. It is capable of attaining a Faradaic efficiency of 76.6 % and a large NH3 yield of up to 99.6 μmol cm−2 h−1. The MoS2-based Zn-NO battery delivers a power density of 1.04 mW cm−2 with an NH3 yield of 411.8 μg h−1 mgcat.−1.

Metallofulleroids | Hot Paper

Unexpected Formation of Metallofulleroids from Multicomponent Reactions, with Crystallographic and Computational Studies of the Cluster Motion

  • Pages: 25269-25273
  • First Published: 24 September 2021
Description unavailable

Various metallofulleroids were generated from a new isocyanide-induced multicomponent reaction on clusterfullerenes. One ketenimine metallofulleroid has fixed Lu3N cluster due to the presence of the nearby organic appendant from a neighbor molecule in the solid state.

Water Dynamics | Hot Paper

Open Access

Probing Water State during Lipidic Mesophases Phase Transitions

  • Pages: 25274-25280
  • First Published: 23 September 2021
Description unavailable

We study the phase transitions from cubic to reverse hexagonal phase in lipidic mesophase at molecular level. The dynamics of both water and lipids, as well as the hydrogen bond network of confined water were monitored during the phase transition. The results demonstrate clear dynamical difference between bound and interstitial water in both phases.

C−C Bond Formation

Reactions of a Dilithiomethane with CO and N2O: An Avenue to an Anionic Ketene and a Hexafunctionalized Benzene

  • Pages: 25281-25285
  • First Published: 24 September 2021
Description unavailable

The dianion [(Ph2P(S))2CLi2(THF)]2 1 reacts with CO affording C−C bond formation and Ph2P(S)-fragment migration. Subsequent reaction with N2O cleaves a P−C bond generating an anionic ketene-derivative which cyclotrimerizes to give the hexa-substituted benzene derivative, [Ph2P(S)COLi(THF)2]3 6 regioselectively. The experimental observations are rationalized by a detailed theoretical study of the reaction mechanism by state-of-the-art DFT methods.

Heteroallenes | Hot Paper

Synthesis, Structure and Reactivity of a Cyapho-Cyanamide Salt

  • Pages: 25286-25289
  • First Published: 23 September 2021
Description unavailable

We describe the step-wise synthesis of the novel cyapho-cyanamide ion, [N(CN)(CP)], obtained by the reaction of sodium phosphanide, Na(PH2), with dimethyl N-cyanocarbonimidate, (MeO)2C=N(CN). Preliminary reactions of the ion with electrophiles reveal the cyclisation reactions are available on functionalisation.

Photoswitches | Hot Paper

Open Access

Phenylimino Indolinone: A Green-Light-Responsive T-Type Photoswitch Exhibiting Negative Photochromism

  • Pages: 25290-25295
  • First Published: 05 October 2021
Description unavailable

Visible-light-responsive T-type photoswitches with negative photochromism are rare and interesting candidates for a wide range of applications. Here, we describe the computer-assisted rational design of phenylimino indolinone (PIO) and its characterization in the ground and excited state using the full toolbox of physical organic chemistry.

Single-Atom Catalysis | Hot Paper

Dynamic Control of Sacrificial Bond Transformation in the Fe−N−C Single-Atom Catalyst for Molecular Oxygen Reduction

  • Pages: 25296-25301
  • First Published: 15 September 2021
Description unavailable

Bond breaking/re-formation to tune local coordination: Deliberate construction and subsequent selective cleavage of sacrificial Fe−S bonds render flexible tunability to control the local coordination of metal single atoms. The oxidized sulfur functionalization around the Fe center helps the Fe−N−C reach the ORR volcano-plot apex by optimizing the adsorption strength of the oxygenated intermediates.

Nonlinear Optical Crystals | Hot Paper

An Effective Strategy for Designing Nonlinear Optical Crystals by Combining the Structure-Directing Property of Oxyfluorides with Chemical Substitution

  • Pages: 25302-25306
  • First Published: 27 September 2021
Description unavailable

A non-centrosymmetric and polar Ba2[MoO3F(IO3)](MoO3F2) was synthesized by combining the structure-directing property of oxyfluorides with chemical substitution. Measurement of the optical properties shows that the compound satisfies all key property requirements to be promising application from UV to mid-infrared regions as SHG materials.

Suzuki–Miyaura Coupling

Desulfonative Suzuki–Miyaura Coupling of Sulfonyl Fluorides

  • Pages: 25307-25312
  • First Published: 27 September 2021
Description unavailable

Aryl sulfonyl fluorides, typically inert to transition metal catalysis, undergo a Pd-catalyzed desulfonative Suzuki–Miyaura coupling. The reaction can occur without added base and turns the −SO2F group into a divergent handle for C−C or S−Nu coupling.

Synthetic Methods | Hot Paper

Chiral Benzothiophene Synthesis via Enantiospecific Coupling of Benzothiophene S-Oxides with Boronic Esters

  • Pages: 25313-25317
  • First Published: 28 September 2021
Description unavailable

The C2 alkylation of functionalized benzothiophenes has been explored. Enantiospecific C−C bond formation is achieved via O-activation and 1,2-metalate shift of benzothiophene S-oxide boronate complexes, which enables expedient access to chiral C2-alkylated benzothiophenes.

Supercapacitors | Hot Paper

MXene-Copper/Cobalt Hybrids via Lewis Acidic Molten Salts Etching for High Performance Symmetric Supercapacitors

  • Pages: 25318-25322
  • First Published: 28 September 2021
Description unavailable

Ti3C2 MXene-Cu/Co hybrids were fabricated through molten salt etching for illustrating their interactions. The pseudocapacitive contribution of Cu and a splendid specific capacitance of Ti3C2-Cu were demonstrated. A symmetric supercapacitor based on Ti3C2-Cu electrode delivered a high energy density of 103.3 μWh cm−2 at 0.8 mW cm−2.

2D Conjugated Polymers

1,6-Anthrazoline-Linked π-Conjugated Macrocycles and Two-Dimensional Polymer via Friedländer Synthesis

  • Pages: 25323-25327
  • First Published: 25 September 2021
Description unavailable

An old chemistry, but a new efficient method for the synthesis of π-conjugated macrocycles and 2D polymer! We demonstrated that Friedländer synthesis which involves both dynamic imine condensation and aldol condensation is highly effective for the synthesis of kinetically stable, 1,6-anthrazoline-based all sp2 C/N containing macrocycles and crystalline 2D polymer.

Research Articles

Photothermal Therapy | Hot Paper

A Titanium Nitride Nanozyme for pH-Responsive and Irradiation-Enhanced Cascade-Catalytic Tumor Therapy

  • Pages: 25328-25338
  • First Published: 28 August 2021
Description unavailable

N-doping significantly improves the peroxidase (POD) activity of titanium-based nanozymes. Titanium nitride nanoparticles (TiN NPs) showed enhanced POD activity under NIR laser irradiation due to surface plasmon resonance (SPR) and temperature effects. Combined with glucose oxidase in liposomes, a TiN-NP-based nanoplatform (TLGp) showed an excellent antitumor activity under NIR-mediated mild thermal conditions through its cascade-catalytic activity.

Self-Assembly

Mechanical Enhancement and Kinetics Regulation of Fmoc-Diphenylalanine Hydrogels by Thioflavin T

  • Pages: 25339-25345
  • First Published: 30 September 2021
Description unavailable

Thioflavin T dramatically enhances the structural and mechanical properties of the Fmoc-FF hydrogel and drives the self-assembly by interfering the metastable phase of the two-step nucleation process.

Proteins | Very Important Paper

APEX2-based Proximity Labeling of Atox1 Identifies CRIP2 as a Nuclear Copper-binding Protein that Regulates Autophagy Activation

  • Pages: 25346-25355
  • First Published: 22 September 2021
Description unavailable

Seeking to overcome challenges with the identification of copper chaperone protein's binding partners, we used APEX2-based proximity labeling with Atox1 as the bait to identify weak/transient protein–protein interactions. Atox1 delivers copper into the nucleus and transfers it to a previously unrecognized nuclear copper binding protein CRIP2, and copper promotes CRIP2 degradation to induce ROS-mediated activation of autophagy.

Polymerisation | Hot Paper

Open Access

Block Copolymers Based on Ethylene and Methacrylates Using a Combination of Catalytic Chain Transfer Polymerisation (CCTP) and Radical Polymerisation

  • Pages: 25356-25364
  • First Published: 21 September 2021
Description unavailable

Catalytic chain transfer polymerisation was used to produce methacrylic macromonomers. Those were involved in a simple radical polymerisation of ethylene to form block copolymers featuring a polyethylene segment and various polymethacrylic segments.

Anti-Cancer Therapy | Hot Paper

Smart Tumor-Cell-Derived Microparticles Provide On-Demand Photosensitizer Synthesis and Hypoxia Relief for Photodynamic Therapy

  • Pages: 25365-25371
  • First Published: 16 September 2021
Description unavailable

Accurate co-localization of PpIX and O2: HAL and 3BP-loaded microparticles specifically target and recognize tumor cells, wherein HAL induces the biosynthesis of PpIX in mitochondria and 3BP reduces the mitochondria oxygen consumption. The precise co-localization of PpIX and O2 produces sufficient singlet oxygen to directly disrupt mitochondria, significantly improving PDT.

Hydrogenation Catalysts | Hot Paper

Open Access

Reduction of Nitrogen Oxides by Hydrogen with Rhodium(I)–Platinum(II) Olefin Complexes as Catalysts

  • Pages: 25372-25380
  • First Published: 12 September 2021
Description unavailable

Catalyzed hydrogenation of NO2, NO, and N2O is achieved under mild conditions by air stable olefin RhI–PtII bimetallic complexes. In the molecular catalysts, the Rh−Pt interaction is a direct metal−metal bond and cooperativity of both metals in substrate activation is proposed based on DFT. A hyponitrite rhodium complex is a key intermediate for the N−N bond-forming step in the catalytic reduction of NO.

Water Splitting

Ultrathin Crystalline Covalent-Triazine-Framework Nanosheets with Electron Donor Groups for Synergistically Enhanced Photocatalytic Water Splitting

  • Pages: 25381-25390
  • First Published: 21 September 2021
Description unavailable

Ultrathin crystalline 2D triazine polymer nanosheets with electron donor groups are prepared for the first time by a novel redox strategy. They demonstrate ultrahigh photocatalytic overall water splitting performance arising from the optimized band structure and improved light-responsive range from the electron donor groups introduced into the 2D ordered molecular plane.

Crystals

Open Access

Local Ordering of Molten Salts at NiO Crystal Interfaces Promotes High-Index Faceting

  • Pages: 25391-25396
  • First Published: 18 August 2021
Description unavailable

With density functional theory, the phenomena that drive the shape selectivity of NiO particles crystallized by molten salt synthesis were studied. Trapezohedral NiO particles are shown to form in LiCl and KCl due to the interaction of locally ordered alkali-chloride structures with the growing high-index oxide facets, thus acting as capping agents. In the absence of salt, octahedral NiO formation is driven by the dissociative adsorption of water.

Glycosylation | Hot Paper

Direct Experimental Characterization of a Bridged Bicyclic Glycosyl Dioxacarbenium Ion by 1H and 13C NMR Spectroscopy: Importance of Conformation on Participation by Distal Esters

  • Pages: 25397-25403
  • First Published: 20 September 2021
Description unavailable

Simple methylation at the 4-position of a 4-O-benzoyl galactopyranosyl donor enables direct observation by low-temperature NMR spectroscopy of the previously elusive bridging dioxacarbenium ion, supporting the hypothesis that distal group participation by secondary esters is disfavored by the conformation of the ester.

Oxygen Reduction Reaction

Unraveling the Origin of Sulfur-Doped Fe-N-C Single-Atom Catalyst for Enhanced Oxygen Reduction Activity: Effect of Iron Spin-State Tuning

  • Pages: 25404-25410
  • First Published: 22 September 2021
Description unavailable

The enhanced oxygen reduction reaction (ORR) activity of sulfur-doped Fe-N-C single-atom catalysts is studied from Fe spin-state tuning. Operando 57Fe Mössbauer spectra monitoring further supported the low-spin (LS) single-Fe3+-atom of the C-FeN4-S moiety as the active site for the ORR.

Heterogeneous Catalysis

Single-Phase Formation of Rh2O3 Nanoparticles on h-BN Support for Highly Controlled Methane Partial Oxidation to Syngas

  • Pages: 25411-25418
  • First Published: 15 September 2021
Description unavailable

A single-phase Rh2O3 nanocatalyst is developed by exploiting the stabilization of the (110) plane of the Rh2O3(I) seed on hexagonal boron nitride (h-BN) after decomposition of the rhodium precursor. By using the Rh/h-BN, catalytic methane partial oxidation to syngas was accomplished solely via the direct route.

Physical Chemistry | Hot Paper

Open Access

Proton Traffic Jam: Effect of Nanoconfinement and Acid Concentration on Proton Hopping Mechanism

  • Pages: 25419-25427
  • First Published: 16 August 2021
Description unavailable

The mechanism of proton transport within nonionic reverse micelles is dependent on the proton concentration ([H+]) and the size of the nanoconfined environment. For small reverse micelles and/or low [H+], protons diffuse via the Grotthuss mechanism (forward hopping). In larger reverse micelles and/or at high [H+], ions accumulate at the reverse micelles interface, resulting in a proton “traffic jam,” in which an oscillatory hopping mechanism becomes dominant.

Protein Structure | Hot Paper

NMR Spectroscopy of the Main Protease of SARS-CoV-2 and Fragment-Based Screening Identify Three Protein Hotspots and an Antiviral Fragment

  • Pages: 25428-25435
  • First Published: 27 September 2021
Description unavailable

We report the liquid-sate NMR spectroscopy analysis of the dimeric SARS-CoV-2 main protease (3CLp), including its backbone assignments, to study its complex conformational regulation. Using fragment-based NMR screening, we highlighted three hotspots on the protein, two in the substrate binding pocket and one at the dimer interface, and we identified a non-covalent reversible inhibitor of 3CLp that has antiviral activity in infected cells.

Interfacial Patterning

Plenty of Room at the Top: A Multi-Scale Understanding of nm-Resolution Polymer Patterning on 2D Materials

  • Pages: 25436-25444
  • First Published: 21 September 2021
Description unavailable

Striped phase polydiacetylenes create 1-nm-resolution chemical patterns on 2D materials, well below the limits possible through most fabrication methods. A new multi-scale view of polymerization enables the design of monomers that undergo efficient on-surface polymerization, opening the door to new applications that rely on stable, near-atomic-scale chemical environments.

Nanographenes

Stepwise Generation of Mono-, Di-, and Triply-Reduced Warped Nanographenes: Charge-Dependent Aromaticity, Surface Nonequivalence, Swing Distortion, and Metal Binding Sites

  • Pages: 25445-25453
  • First Published: 23 September 2021
Description unavailable

Stepwise chemical reduction of a molecular warped nanographene (WNG, 1) with Cs metal affords the mono-, di-, and triply-reduced nanosized carbanions. In-depth X-ray crystallographic analysis and comprehensive theoretical investigations of this series of negatively charged nanographenes reveal a very complex response and core flexibility upon multi-electron charging.

Molecular Recognition | Hot Paper

Radically Enhanced Dual Recognition

  • Pages: 25454-25462
  • First Published: 02 August 2021
Description unavailable

Double the stoichiometry in radical recognition: A highly selective and efficient protocol, based on radical-pairing interactions, was developed for the recognition of two viologen radical cations in solution using a size-matched radical host.

Metal–Organic Frameworks | Hot Paper

Elimination of Grain Boundary Defects in Zeolitic Imidazolate Framework ZIF-95 Membrane via Solvent-Free Secondary Growth

  • Pages: 25463-25467
  • First Published: 21 September 2021
Description unavailable

A solvent-free secondary growth is developed for facile synthesis of highly oriented and well-intergrown ZIF-95 membranes. The solvent-free secondary growth is not only helpful to control the membrane microstructure and thickness, but also reduce solvent-induced intercrystalline defects, leading to a significant enhancement of the H2 permselectivity for the separation of hydrogen from larger gas molecules compared to solvothermal synthesis.

Enzymes

A Cryptic Plant Terpene Cyclase Producing Unconventional 18- and 14-Membered Macrocyclic C25 and C20 Terpenoids with Immunosuppressive Activity

  • Pages: 25468-25476
  • First Published: 27 September 2021
Description unavailable

A cryptic plant terpene cyclase producing unconventional macrocyclic sesterterpenoids and diterpenoids was characterized from Leucosceptrum canum. Two variants producing more sesterterpenoids were engineered, and the immunosuppressive activity of these sesterterpenoids was found.

Photocatalysis

Visible-Light-Induced Selective Photolysis of Phosphonium Iodide Salts for Monofluoromethylations

  • Pages: 25477-25484
  • First Published: 06 September 2021
Description unavailable

Simple and selective synthesis of fluoromethylated alkenes, heterocycles, enamines and heteroarenes by using the readily available and bench-stable fluoromethylphosphonium iodide salts is described. Key to this privileged transformation is the formation of a photoactive charge-transfer complex involving the σ-hole effect of phosphonium salts.

Tandem Catalysis | Hot Paper

Highly Selective Tandem Electroreduction of CO2 to Ethylene over Atomically Isolated Nickel–Nitrogen Site/Copper Nanoparticle Catalysts

  • Pages: 25485-25492
  • First Published: 17 September 2021
Description unavailable

An effective tandem catalysis strategy is developed to enhance the selectivity of the CO2 electroreduction reaction towards C2H4 with a 6-fold increase in comparison with that of the non-tandem catalysts. The local high concentration of CO generated by atomically isolated nickel–nitrogen sites PTF(Ni) sites can facilitate the C−C coupling to form C2H4 on the nearby Cu NP sites, thus switching from CH4 to C2H4 production with a Faradaic efficiency of 57.3 %.

Polymers | Hot Paper

Overcoming the Low Driving Force in Forming Depolymerizable Polymers through Monomer Isomerization

  • Pages: 25493-25498
  • First Published: 09 September 2021
Description unavailable

The cis-to-trans isomerization of fused-ring cyclooctene monomers substantially elevates the driving force in forming depolymerizable polymers, enabling living polymerization and block copolymer synthesis at initial monomer concentration ≥0.025 M. The sequence of isomerization-polymerization-depolymerization forms a unique closed-loop that can be exploited for developing chemically recyclable polymers.

Conjugated Polymers

Revealing the Side-Chain-Dependent Ordering Transition of Highly Crystalline Double-Cable Conjugated Polymers

  • Pages: 25499-25507
  • First Published: 21 September 2021
Description unavailable

When switching the alkyl linkers from C12H24 to C16H32 in double-cable conjugated polymers, perylene bisimide side units exhibited order phase transition from disordered structures to ordered H-aggregation, which is strongly correlated to the photovoltaic performance in single-component organic solar cells.

Batteries | Hot Paper

Fatigue-Resistant Interfacial Layer for Safe Lithium Metal Batteries

  • Pages: 25508-25513
  • First Published: 27 September 2021
Description unavailable

A slide-ring polymer with a high stiffness, high toughness and excellent fracture resistance is designed to adapt its shape to dynamic electrode volume variations and stabilize the lithium anode upon cycling.

Lasers

Solid-State Red Laser with a Single Longitudinal Mode from Carbon Dots

  • Pages: 25514-25521
  • First Published: 22 September 2021
Description unavailable

Red-emissive carbon dots (CDs) with high PLQY (65.5 %) were obtained from aliphatic precursors by combining graphitic nitrogen doping and surface modification. A planar microcavity with only one resonant mode, which fitted with the CDs’ amplified spontaneous emission (ASE) peak, was constructed and resulted in a solid-state laser with a single longitudinal mode, a linewidth of 0.14 nm and a signal-to-noise ratio of 14.8 dB.

Coordination Complexes

Stabilization of the Elusive Antimony(I) Cation and Its Coordination Complexes with Transition Metals

  • Pages: 25522-25529
  • First Published: 09 September 2021
Description unavailable

The elusive SbI cation has been stabilized by the 5,6-bis(diisopropylphosphino)acenaphthene ligand (see structure). The bis(phosphine) not only acts as a supporting ligand, but also enables the unique two-electron reduction of the SbIII precursor in the presence of trimethylsilyl triflate, leading to SbI cation. The strategically introduced nucleophilicity at the SbI site enabled the first examples of its coordination to transition metals.

Oxygen Reduction

Boosting Oxygen Reduction via Integrated Construction and Synergistic Catalysis of Porous Platinum Alloy and Defective Graphitic Carbon

  • Pages: 25530-25537
  • First Published: 25 September 2021
Description unavailable

A porous platinum-rich alloy encapsulated by graphitic carbon results in improved oxygen reduction reaction (ORR) performance as a result of the interaction between the ternary PtCuCo alloy and graphitic Co-N-C units.

Heterogeneous Catalysis

The Facile Dissociation of Carbon–Oxygen Bonds in CO2 and CO on the Surface of LaCoSiHx Intermetallic Compound

  • Pages: 25538-25545
  • First Published: 14 September 2021
Description unavailable

In this work, the facile dissociation of CO2 and CO on the surface of the LaCoSiHx catalyst is observed at room temperature. This is attributed to the marked electron transfer from catalysts into the antibonding orbital of CO2 and CO.

Photocatalysis

Iodide-Induced Fragmentation of Polymerized Hydrophilic Carbon Nitride for High-Performance Quasi-Homogeneous Photocatalytic H2O2 Production

  • Pages: 25546-25550
  • First Published: 17 September 2021
Description unavailable

Iodide ions are utilized as an inhibitor for terminating the polymerization of PCN (TP-PCN). The resulting ultrathin and small-sized TP-PCN have abundant edge active sites (AEASs). They greatly enhance the O2 adsorption/activation capacity and the 2 e oxygen reduction reaction (ORR) selectivity. As expected, the TP-PCN affords a remarkably increased photocatalytic H2O2 production activity.

Nanographenes | Hot Paper

Open Access

On-Surface Synthesis of a Dicationic Diazahexabenzocoronene Derivative on the Au(111) Surface

  • Pages: 25551-25556
  • First Published: 21 September 2021
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A hexabenzocoronene derivative embedded with graphitic nitrogen in its honeycomb lattice is prepared by on-surface assisted cyclodehydrogenation on the Au(111) surface. Combined scanning tunnelling microscopy/spectroscopy and non-contact atomic force microscopy investigations unveil the chemical and electronic structures of the obtained dicationic nanographene.

Cancer Therapy

Supramolecular Self-Assembled DNA Nanosystem for Synergistic Chemical and Gene Regulations on Cancer Cells

  • Pages: 25557-25566
  • First Published: 17 September 2021
Description unavailable

A supramolecular self-assembled DNA nanosystem that reprograms the cellular antioxidant system via synergistic chemical and gene regulations is reported, achieving an efficient suppression of breast cancer.

Perovskites

Ferrocene-Induced Perpetual Recovery on All Elemental Defects in Perovskite Solar Cells

  • Pages: 25567-25574
  • First Published: 21 September 2021
Description unavailable

Towards stable solar cells, ferrocene as a perpetual recovering agent has been developed to fix all elemental defects in ABX3 perovskite by a chain-reaction cycle. The ferrocene cations can form a 1D perovskite structure which has suitable dissociation energy to convert back to light-harvesting 3D perovskite and reactivate its photovoltaic performance. Based on this recovering agent, perovskite solar cell can achieve >10 000 h lifetime.

Batteries | Very Important Paper

A Low-Strain Phosphate Cathode for High-Rate and Ultralong Cycle-Life Potassium-Ion Batteries

  • Pages: 25575-25582
  • First Published: 24 September 2021
Description unavailable

A low-strain phosphate cathode material K3(VO)(HV2O3)(PO4)2(HPO4) (KVP) nanoruler is synthesized by a facile solvothermal approach. The KVP nanorulers manifest high discharge voltage, superior rate capability, and ultralong cyclic life as a cathode material for potassium-ion batteries (PIBs). This work would provide guidance to exploit high-performance PIB cathode materials.