Angewandte Chemie International Edition

Cover image for Vol. 55 Issue 27

Editor: Peter Gölitz, Deputy Editors: Neville Compton, Haymo Ross

Online ISSN: 1521-3773

Associated Title(s): Angewandte Chemie, Chemistry - A European Journal, Chemistry – An Asian Journal, ChemistryOpen, ChemPlusChem, Zeitschrift für Chemie

Upcoming Hot Papers

Hot Papers are chosen by the Editors for their importance in a rapidly evolving field of high current interest. Many of the "Very Important Papers" (VIPs) would certainly qualify to be included here, but such a duplication is avoided.

Peptide Coatings

Easy Access toward Functional Patterns on Cellulose Paper by Combining Laser Printing and Material-Specific Peptide Adsorption

Easy Access toward Functional Patterns on Cellulose Paper by Combining Laser Printing and Material-Specific Peptide Adsorption

Stick to print: Selective coating of laser-printed patterns was achieved by material-specific adhesion of peptides to cellulose or toner. The peptide sequences were obtained using phage display. Functionalization of the immobilized peptides was realized by selective modification of tyrosine residues present on the printed-pattern coatings, offering new ways towards low-cost printed devices.

Read more now


 

Gas Separation

A Highly Permeable Aligned Montmorillonite Mixed-Matrix Membrane for CO2 Separation

A Highly Permeable Aligned Montmorillonite Mixed-Matrix Membrane for CO2 Separation

A mixed-matrix membrane consisting of aligned montmorillonite (AMT) and polysulfone was prepared for CO2 separation. The MT interlayer gaps were aligned with polyvinylamineacid chains that had been grafted onto the surface of the hydroxylated polysulfone substrate. The high-speed transport channels in AMT result in high CO2 permeance and mixed-gas permselectivity.

Read more now


 

Multicomponent Reactions

Insertion of Isocyanides into N−Si Bonds: Multicomponent Reactions with Azines Leading to Potent Antiparasitic Compounds

Insertion of Isocyanides into N−Si Bonds: Multicomponent Reactions with Azines Leading to Potent Antiparasitic Compounds

Insert here! Multicomponent reactions (MCRs) with isoquinolines and other azines that proceed through the insertion of an isocyanide into a N−Si bond are described. This novel activation mode enables a variety of transformations to take place with high selectivity under mild reaction conditions. Some of the products showed in vitro activity against the causative agents of trypanosomiasis. TMS=trimethylsilyl.

Read more now


 

Molecular Devices

Alcohol-Mediated Resistance-Switching Behavior in Metal–Organic Framework-Based Electronic Devices

Alcohol-Mediated Resistance-Switching Behavior in Metal–Organic Framework-Based Electronic Devices

A MOF never forgets: Alcohol-mediated memory devices with reliable resistance-switching properties were realized in metal–organic framework (MOF) films. The memory behavior can be controlled by the intermolecular interactions among the guest molecules adsorbed in MOF crystals to achieve multilevel information storage.

Read more now


 

C−F Activation

Single C−F Bond Cleavage of Trifluoromethylarenes with an ortho-Silyl Group

Single C−F Bond Cleavage of Trifluoromethylarenes with an ortho-Silyl Group

One of the three: The transformation of a single C−F bond of trifluoromethylarenes bearing an ortho-hydrosilyl group is described. The activation of the hydrosilyl group with a trityl cation in the presence of nucleophiles enabled selective C−F bond functionalization, for example, by allylation, carboxylation, or chlorination. Further derivatization of the resulting fluorosilylarenes afforded various difluoromethylated arenes.

Read more now


 

Inorganic Chemistry

Oxidation State 10 Exists

Oxidation State 10 Exists

An existential conundrum: The stability of transition metal compounds with a metal formal oxidation state of 10 was determined with Kohn–Sham density functional theory, and PtO42+ was found to be stable. PtO42+ reveals a similar electron density but a larger partial atomic charge on the metal when compared to IrO4+, for which the highest oxidation state of 9 was previously found.

Read more now


 

Perovskite Solar Cells

Hexaazatrinaphthylene Derivatives: Efficient Electron-Transporting Materials with Tunable Energy Levels for Inverted Perovskite Solar Cells

Hexaazatrinaphthylene Derivatives: Efficient Electron-Transporting Materials with Tunable Energy Levels for Inverted Perovskite Solar Cells

Only sulfur has the answer: Fine tuning of the energy levels and solution processability of hexaazatrinaphthylene (HATNA) derivatives is achieved by introducing alkylsulfanyl chains of various chain lengths and with different sulfur oxidation states. Perovskite solar cells employing these HATNA derivatives as electron-transporting materials exhibited excellent performances, with power conversion efficiencies (PCE) up to 17.6 %.

Read more now


 

C−H Activation

Catalytic C(sp3)−H Arylation of Free Primary Amines with an exo Directing Group Generated In Situ

Catalytic C(sp3)−H Arylation of Free Primary Amines with an exo Directing Group Generated In Situ

The direct arylation of unactivated aliphatic C−H bonds in free primary amines was achieved by using an exo-imine-type directing group (DG) that can be generated and removed in situ. Both primary aliphatic amines and anilines are suitable substrates, and methyl as well as cyclic and acyclic methylene groups smoothly underwent site-selective arylation.

Read more now


 

Crystal Growth

Determination of the Preassembled Nucleating Units That Are Critical for the Crystal Growth of the Metal–Organic Framework CdIF-4

Determination of the Preassembled Nucleating Units That Are Critical for the Crystal Growth of the Metal–Organic Framework CdIF-4

Growth agents: Through the combined use of in situ atomic force microscopy and mass spectrometry, several preformed cadmium-containing species that are present in the growth solution of the cadmium 2-ethylimidazolate metal–organic framework CdIF-4 were identified. Their presence was shown to be critical for surface nucleation.

Read more now


 

Synthetic Biology

Short Self-assembling Peptides are Able to Bind to Copper and Activate Oxygen

Short Self-assembling Peptides are Able to Bind to Copper and Activate Oxygen

Let's get together: De novo designed peptides were developed that self-assemble in the presence of copper to create supramolecular assemblies that catalyze the oxidation of dimethoxyphenol in the presence of dioxygen. Formation of the supramolecular assembly, which is akin to a protein fold, is critical for productive catalysis since peptides possessing the same functional groups but lacking the ability to self-assemble do not catalyze substrate oxidation.

Read more now


 

Homogeneous Catalysis

Dizinc Lactide Polymerization Catalysts: Hyperactivity by Control of Ligand Conformation and Metallic Cooperativity

Dizinc Lactide Polymerization Catalysts: Hyperactivity by Control of Ligand Conformation and Metallic Cooperativity

Ring-opening polymerization: Dinuclear and analogous mononuclear zinc complexes embedded in bis(imino)diphenylamido ligands were synthesized and used as catalysts for the ring-opening polymerization (ROP) of racemic lactide (LA). The catalysts with “folded” ligands show high turnover frequency (TOF) values, which are up to 5500 times higher than those for “flat” ligands (see picture).

Read more now


 

Heterogeneous Catalysis

Nitrogen-Doped Ordered Mesoporous Carbon Supported Bimetallic PtCo Nanoparticles for Upgrading of Biophenolics

Nitrogen-Doped Ordered Mesoporous Carbon Supported Bimetallic PtCo Nanoparticles for Upgrading of Biophenolics

The phenol cut: A novel method allows the synthesis of bimetallic PtCo nanoparticles (ca.1.5 nm) which are highly dispersed in the framework of nitrogen-doped ordered mesoporous carbon (NOMC). The resulting PtCo-NOMC shows high catalytic activity for hydrodeoxygenation of phenolic compounds and “real-world” biomass-derived phenolic streams.

Read more now


 

Stacked Assemblies

Two- and Three-Tiered Stacked Architectures by Covalent Assembly

Two- and Three-Tiered Stacked Architectures by Covalent Assembly

Discrete stacks: Two- and three-tiered covalent compounds are obtained through imine condensation. The final structures, formally fused cages, comprise a central stack of arenes embedded within a triple helix. The rate of racemization depends strongly on the number of tiers because of conformational coupling in these highly interconnected structures.

Read more now


 

Conformational Analysis

The meso Helix: Symmetry and Symmetry-Breaking in Dynamic Oligourea Foldamers with Reversible Hydrogen-Bond Polarity

The meso Helix: Symmetry and Symmetry-Breaking in Dynamic Oligourea Foldamers with Reversible Hydrogen-Bond Polarity

Reversible foldamers: Urea oligomers of meso-cyclohexane-1,2-diamine form a dynamic racemic mixture of 2.512/14 helices in which screw-sense inversion is coupled with reversal of hydrogen-bond directionality. Desymmetrization induces a preferred directionality and screw sense.

Read more now


 

C−H Bond Activation

Highly Stereoselective Cobalt(III)-Catalyzed Three-Component C−H Bond Addition Cascade

Highly Stereoselective Cobalt(III)-Catalyzed Three-Component C−H Bond Addition Cascade

Essential bond connections: A highly stereoselective three-component C(sp2)−H bond addition across alkene and polarized π-bonds is reported. Catalysis by CoIII was much more effective than by RhIII, providing products in good yield and with high diastereoselectivity for a broad range of aldehydes. The first asymmetric reactions employing CoIII-catalyzed C−H functionalization are also reported for three-component C−H bond addition cascades with N-tert- butanesulfinyl imines.

Read more now


 

Nanocapsules

Hollow Carbon Nanobubbles: Synthesis, Chemical Functionalization, and Container-Type Behavior in Water

Hollow Carbon Nanobubbles: Synthesis, Chemical Functionalization, and Container-Type Behavior in Water

Hollow carbon nanobubbles: Water-dispersible, carbon-based nanobubbles, synthesized by metal templating, spontaneously take up cargo by hydrophobic interactions. The slow release of the cargo follows an unexpected out-of-equilibrium (hysteretic) behavior.

Read more now


 

Imaging

Cross-Platform DNA Encoding for Single-Cell Imaging of Gene Expression

Cross-Platform DNA Encoding for Single-Cell Imaging of Gene Expression

Now you see it: DNA encoding chemistry combined with multiplexed imaging enables simultaneous in situ interrogation of a panel of selected DNA, RNA, and/or protein markers (red, blue, and green probes, respectively) in single cells by bringing different target types onto the same detection platform. In a proof-of-concept study with multicolor quantum dot probes, DNA encoding was used to explore the spatial and temporal aspects of cell transfection and RNAi.

Read more now


 

Host–Guest Systems

Iminium Catalysis inside a Self-Assembled Supramolecular Capsule: Modulation of Enantiomeric Excess

Iminium Catalysis inside a Self-Assembled Supramolecular Capsule: Modulation of Enantiomeric Excess

An accommodating host: The iminium-catalyzed 1,4-reduction of unsaturated aldehydes can be performed inside a supramolecular host. Only catalytic amounts of the supramolecular capsule are required. The intermolecular, noncovalent interactions inside the host system dramatically improve enantioselectivity for several amine catalysts.

Read more now


 

Enantioselective Catalysis

Radical Changes in Lewis Acid Catalysis: Matching Metal and Substrate

Radical Changes in Lewis Acid Catalysis: Matching Metal and Substrate

The choice of metal for an enantioselective catalyzed process depends on its preferred coordination geometry, redox reactivity, and the possible metal–substrate interactions. These are well matched in the boxmi/CuII-catalyzed electrophilic alkylation of β-ketoesters, whereas oxindoles react in an unselective radical process. However, they can be converted with excellent enantioselectivity in the presence of ZnII catalysts.

Read more now


 

Ordered Nanoparticles

Ordered PdCu-Based Nanoparticles as Bifunctional Oxygen-Reduction and Ethanol-Oxidation Electrocatalysts

Ordered PdCu-Based Nanoparticles as Bifunctional Oxygen-Reduction and Ethanol-Oxidation Electrocatalysts

Non-platinum electrocatalysts for fuel-cell reactions, composed of ordered intermetallic PdCuM nanoparticles (NPs; M=Ni or Co), have been synthesized. These ordered PdCuM NPs are generally much more active and stable than the conventional disordered counterparts and also the commercial Pt/C and Pd/C catalysts, towards both the ethanol-oxidation and oxygen-reduction reactions (ADTs=accelerated durability tests).

Read more now


 

Microfluidics

A Method for Detecting Circulating Tumor Cells Based on the Measurement of Single-Cell Metabolism in Droplet-Based Microfluidics

A Method for Detecting Circulating Tumor Cells Based on the Measurement of Single-Cell Metabolism in Droplet-Based Microfluidics

An altered metabolism is one of the hallmarks of cancer cells. Differences between healthy and cancerous cell metabolism, hidden in bulk, are apparent in tiny (pL) droplets containing individual cells. Within minutes, cancerous cells generate a pH change in their microenvironment. By measuring the pH value in each droplet, circulating tumor cells (CTCs) can be detected in patient samples. WBC=white blood cell; lac=lactate.

Read more now


 

Biosynthesis

Cyclic Guanidine Compounds from Toxic Newts Support the Hypothesis that Tetrodotoxin is Derived from a Monoterpene

Cyclic Guanidine Compounds from Toxic Newts Support the Hypothesis that Tetrodotoxin is Derived from a Monoterpene

Eye of newt: On the basis of a proposed pathway for tetrodotoxin formation, a screening of biosynthetic intermediates was carried out. Five cyclic guanidine compounds, including Cep-210 (see picture), were found in toxic newts, and their elucidated structures support the hypothesis that tetrodotoxin is derived from a monoterpene.

Read more now


 

Hydrogen Production

A Highly Efficient Sandwich-Like Symmetrical Dual-Phase Oxygen-Transporting Membrane Reactor for Hydrogen Production by Water Splitting

A Highly Efficient Sandwich-Like Symmetrical Dual-Phase Oxygen-Transporting Membrane Reactor for Hydrogen Production by Water Splitting

Sandwich-like membrane reactor: H2 production by means of water splitting coupled with partial oxidation of methane (POM) is conducted in a sandwich-like symmetrical dual-phase membrane reactor. The infiltrated Ni nanoparticles (red spheres) significantly enhance the number of reactive sites and also catalyze the POM reaction. Furthermore, the membrane reactor can regenerate the coked catalyst in situ using steam.

Read more now


 

Water Oxidation

Modification of Wide-Band-Gap Oxide Semiconductors with Cobalt Hydroxide Nanoclusters for Visible-Light Water Oxidation

Modification of Wide-Band-Gap Oxide Semiconductors with Cobalt Hydroxide Nanoclusters for Visible-Light Water Oxidation

When rutile TiO2, a wide-band-gap semiconductor, is modified with cobalt hydroxide nanoclusters, it can be used for photocatalytic water oxidation under visible-light irradiation at wavelengths of up to 850 nm. This material thus constitutes the first particulate photocatalyst that operates at such long wavelengths.

Read more now


 

Graphene Nanostructures

The Nanoparticle Size Effect in Graphene Cutting: A “Pac-Man” Mechanism

The Nanoparticle Size Effect in Graphene Cutting: A “Pac-Man” Mechanism

Surface or interface? By employing a multiscale simulation approach, a “Pac-Man” mechanism is revealed for the nickel-nanoparticle-catalyzed cutting of graphene. Although the overall cutting rate is proportional to the surface area of the nanoparticle, it is found that the rate-limiting step is actually at the graphene–metal interface instead of on the nanoparticle surface.

Read more now


 

Venom Peptides

Autocrine-Based Selection of Drugs that Target Ion Channels from Combinatorial Venom Peptide Libraries

Autocrine-Based Selection of Drugs that Target Ion Channels from Combinatorial Venom Peptide Libraries

Pick your poison: Cysteine-knot peptides were extracted from the venom database by using bioinformatics and used to create a lentiviral vector library for the autocrine-based selection of peptides targeting ion channels. Interaction of the membrane-tethered venom peptide with the ion channel results in the protease-mediated release of a transcription factor (orange), which triggers expression of a reporter gene (red).

Read more now


 

Photocatalysis

Chromoselective Photocatalysis: Controlled Bond Activation through Light-Color Regulation of Redox Potentials

Chromoselective Photocatalysis: Controlled Bond Activation through Light-Color Regulation of Redox Potentials

I see your two colors, shining through: The xanthene dye rhodamine 6G is a moderately reducing photoredox catalyst if irradiated with green light, but provides an high reduction power of −2.4 V vs. SCE upon blue-light irradiation. This allows control of the selectivity of photocatalytic C−H arylation reactions through changing the color of the light.

Read more now


 

Atomic-Scale Engineering

Low-Temperature Cationic Rearrangement in a Bulk Metal Oxide

Low-Temperature Cationic Rearrangement in a Bulk Metal Oxide

The unprecedented low-temperature (150–300 °C) cationic rearrangement in bulk Mn2FeMoO6 leads to a transition from a Ni3TeO6-type to an ordered-ilmenite structure, and dramatic changes of the electrical and magnetic properties, which demonstrates remarkable physical property tunneling through atomic-scale manipulation in bulk oxide under mild conditions.

Read more now


 

Molecular Motion

Dissipative and Autonomous Square-Wave Self-Oscillation of a Macroscopic Hybrid Self-Assembly under Continuous Light Irradiation

Dissipative and Autonomous Square-Wave Self-Oscillation of a Macroscopic Hybrid Self-Assembly under Continuous Light Irradiation

Oscillate wildly: In a limit-cycle self-oscillatory motion of a macroscopic assembly, the assembly permanently flips under continuous blue-light irradiation. Mechanical self-oscillation showing a spatio-temporal pattern is established by successively alternating photoisomerization processes and multi-stable phase transitions.

Read more now


 

Oxygen Reduction

Nitrogen-Rich Manganese Oxynitrides with Enhanced Catalytic Activity in the Oxygen Reduction Reaction

Nitrogen-Rich Manganese Oxynitrides with Enhanced Catalytic Activity in the Oxygen Reduction Reaction

The catalytic activities of manganese oxynitrides with different nitrogen contents in the oxygen reduction reaction (ORR) in alkaline solution were investigated. An increase in the nitrogen content of rock-salt-type manganese oxynitrides increases the valence of manganese and leads to enhanced catalytic activity.

Read more now


 

Spin-Crossover Materials

First Step Towards a Devil's Staircase in Spin-Crossover Materials

First Step Towards a Devil's Staircase in Spin-Crossover Materials

The devil is in the detail: Periodic and aperiodic spin-state concentration waves form during “Devil's staircase”-type spin-crossover in a new bimetallic 2D coordination polymer {Fe[(Hg(SCN)3)2](4,4′-bipy)2}n.

Read more now


 

Analytical Methods

A Disposable Planar Paper-Based Potentiometric Ion-Sensing Platform

A Disposable Planar Paper-Based Potentiometric Ion-Sensing Platform

Paper-based sensors: Embedding a potentiometric cell into paper brings selective ion sensors into the reach of users with limited resources and training. The paper-based device is simple to use, does not need any pretreatment, and requires only a low sample volume of 20 μL. It can be used to detect clinically relevant ions in biological samples with high sensitivity and reproducibility. ISE=ion-selective electrode.

Read more now


 

SEARCH

SEARCH BY CITATION