Angewandte Chemie International Edition
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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.
Hydrogels from Amorphous Calcium Carbonate and Polyacrylic Acid: Bio-Inspired Materials for “Mineral Plastics”
Shapeable, stretchable, recyclable, (thermochromic) amorphous calcium carbonate-based hybrid supramolecular hydrogels were synthesized, which can reversibly form macroscopic rigid transparent films upon drying. This plastic material may potentially replace conventional plastics in a move towards solving environmental issues.
Individualized p-Doped Carbon Nanohorns
I am an individual: A facile approach for the separation of aggregated carbon nanohorns (CNHs), by treatment with chlorosulfonic acid, leads to p-doped species. The acid induces positive charges on the nanohorns which repel and push the individual nanohorns apart. The method yields gram quantities of free nanohorns.
An Epigenetics-Inspired DNA-Based Data Storage System
Information storage: Inspired by the epigenetic regulation of genomic information in cells, it is shown how digital data can undergo controlled changes when encoded in synthetic DNA strands. Chemical transformations were used to alter naturally occurring cytosine derivatives, which enabled the reversible recovery of multiple data layers from a single DNA template (see portraits).
Simplest Monodentate Imidazole Stabilization of the oxy-Tyrosinase Cu2O2 Core: Phenolate Hydroxylation through a CuIII Intermediate
Cold copper cores: Three Nτ-imidazole-bonded CuII2O2 species were synthesized and characterized at low solution temperatures. These complexes resemble the catalytic cores of tyrosinases, and allowed phenolate-ligated CuIII intermediates during hydroxylation reactions to be probed, providing insights into the enzymatic mechanisms.
Reactions between Criegee Intermediates and the Inorganic Acids HCl and HNO3: Kinetics and Atmospheric Implications
Novel sink for Criegee intermediates: The rate constants for the reaction of the simplest Criegee intermediate, CH2OO, with HCl (in green) and HNO3 (in blue) were directly measured by broadband transient absorption spectroscopy. Both reactions occur at or near the collision limit, as was also confirmed by quantum-chemical calculations.
Tuning Pore Size in Square-Lattice Coordination Networks for Size-Selective Sieving of CO2
Sieves you right: Crystal engineering of supramolecular isomers of [Cu(quinoline-5-carboxyate)2]n metal–organic materials enables the right pore-chemistry for ultra-high CO2/N2 and CO2/CH4 selectivity even in the presence of water vapor.
Wide Band-Gap Bismuth-based p-Dopants for Opto-Electronic Applications
Bi doping: Ten new efficient p-dopants for conductivity doping of organic semiconductors for OLEDs are identified. The key advantage of the electrophilic tris(carboxylato)bismuth(III) compounds is the unique low absorption of the resulting doped layers. The combination of this feature with their low fabrication cost, volatility, and stability, make these materials very attractive as dopants in organic electronics.
Fluorinated Azobenzenes for Shape-Persistent Liquid Crystal Polymer Networks
Liquid crystal polymers that contain fluorinated azobenzenes and retain a photochemically generated shape for more than eight days are reported. To preserve photoactivated molecular deformation on the macroscopic scale, the thermal stability of the photoswitch, the cross-linking density in the polymer network, and the molecular orientations in the material have been optimized.
Solid-to-Liquid Charge Transfer for Generating Droplets with Tunable Charge
Charged water: When water droplets flow across surfaces that have been charged by contact electrification, the droplets also become charged. Depending on the charge of the surface, the polarity and magnitude of the charge of the droplets can be controlled. The charge allows the droplets to be manipulated, coalesced, and sorted. This method for generating charged droplet is general, simple and inexpensive.
A Rechargeable Al/S Battery with an Ionic-Liquid Electrolyte
An ionic-liquid electrolyte is employed to give a rechargeable Al/S battery . The hurdle for oxidizing AlSx is addressed by using a microporous carbon/sulfur cathode that can improve the electron access of sulfur species, enlarge interfacial reaction area, and reduce the Al3+ diffusion length (<2 nm). Experimental results indicate that sulfur undergoes solid state conversion reaction in the electrolyte.
Hydrogel Wound Dressing
On-Demand Dissolution of a Dendritic Hydrogel-based Dressing for Second-Degree Burn Wounds through Thiol–Thioester Exchange Reaction
An easily removable dressing: A hydrogel-based dressing for second-degree burn wounds has been synthesized and tested in vivo. It is composed of a dendritic macromonomer and a poly(ethylene glycol) crosslinker that form a hydrogel upon mixing. An on-demand and atraumatic hydrogel dissolution proceeds through thiol–thioester exchange reaction in presence of a cysteine methyl ester solution.
Designer Extracellular Matrix Based on DNA–Peptide Networks Generated by Polymerase Chain Reaction
Catch and release: A functional DNA-based network was generated by PCR and functionalized with a peptide that specifically interacts with certain cell types while others are repelled. By following this approach, specific cell types were attracted to functionalized surfaces. The cells remained viable and could also be easily detached for future studies.
A Dinitrogen Dicopper(I) Complex via a Mixed-Valence Dicopper Hydride
Caught between two coppers: A tris(pyrazolyl)borate (Tp) dicopper N2 complex [CuI]2(μ-N2) forms through the intermediacy of a mixed-valence dicopper hydride [Cu1⋅5]2(μ-H). Besides allowing a direct comparison between N2 and O2 binding at copper(I), this [CuI]2(μ-N2) complex represents a key member in a family of TpCu complexes [CuI]2(μ-NH=NH) and [CuI](NH2NH2) featuring reduced N2 ligands.
Rechargeable Lithium Batteries
Organotrisulfide: A High Capacity Cathode Material for Rechargeable Lithium Batteries
SSSsuitable for batteries: Dimethyl trisulfide (DMTS) was used as a model compound to demonstrate that organotrisulfide compounds can be high capacity cathode materials undergoing multi-electron redox reactions for rechargeable lithium batteries. The lithium/DMTS cell has a high specific energy density of 229 Wh kg−1 as a result of low electrolyte/DMTS ratios.
Second-Generation Non-Covalent NAAA Inhibitors are Protective in a Model of Multiple Sclerosis
Treating neuroinflammation: The cysteine amidase N-acyl ethanolamine acid amidase (NAAA) promotes inflammation by degrading endogenous anti- inflammatory lipid amides such as palmitoylethanolamide (PEA). A new class of non-covalent, orally available NAAA inhibitors (see example) interrupt NAAA-mediated lipid amide degradation in the brain, and are strongly protective in a mouse model of neuroinflammation.
An Iron-Catalyzed Bond-Making/Bond-Breaking Cascade Merges Cycloisomerization and Cross-Coupling Chemistry
Cut and paste: Iron catalysis allows cycloisomerization chemistry and cross-coupling to be merged into a new reaction cascade; this manifold engenders formation of two new C−C bonds at the expense of a C−Z bond in the substrate backbone, which is cleaved while the tetrasubstituted alkene product is forming.
Detection of Cyclo-N5− in THF Solution
N-circled: The cyclopentazolate anion (cyclo-N5−), which is thought to be important for further development of polynitrogen chemistry, has been synthesized in THF and detected by HPLC/MS. The anion is generated by the reduction of phenylpentazole with an alkali metal in THF followed by thermal dissociation. The compound is indefinitely stable below −40 °C, and has a half-life of a few minutes at room temperature.
Hydrogen Evolution Reaction
Porous Molybdenum Phosphide Nano-Octahedrons Derived from Confined Phosphorization in UIO-66 for Efficient Hydrogen Evolution
Decorated for HER: Using the open porosity derived from the pyrolysis of metal–organic frameworks (MOFs), MoO2 small nanoparticles can be deposited in the porous carbon by chemical vapor deposition. Carbonization, nitridation, or phosphorization, selectively gives Mo2C-, MoN-, and MoP-decorated carbocatalysts with unchanged morphology. The catalysts are promising for the hydrogen evolution reaction.
Trapping Aluminum Hydroxide Clusters with Trisilanols during Speciation in Aluminum(III)–Water Systems: Reproducible, Large Scale Access to Molecular Aluminate Models
Picking out early aggregates: Tripodal trisilanols stabilize aluminum hydroxide aggregates formed during the hydrolysis of AliBu2H with different sizes dependent on the amount of water added.
Nickel-Catalyzed Cross-Coupling of Redox-Active Esters with Boronic Acids
A cross-coupling between alkyl carboxylic acids and aryl boronic acids is enabled by a new activation/cross-coupling strategy under Nickel catalysis. The operational simplicity and the wide range of heterocyclic compounds make a convenient strategy for obtaining aryl–alkyl cross-coupling products.
Light-Driven Transport of a Liquid Marble with and against Surface Flows
Sliding marbles: Floating liquid marbles can be transported by light-induced Marangoni flows. Liquid marbles move in the direction of these flows at a large liquid-layer thickness (Marangoni regime) but show a remarkable upstream motion at a low substrate thickness (anti-Marangoni motion). The upstream motion occurs as a result of deformation of the surface of the liquid, a behavior termed the “slide effect”.
Hydrogenation of CO2 to Formic Acid with a Highly Active Ruthenium Acriphos Complex in DMSO and DMSO/Water
Stable environment: The direct hydrogenation of CO2 into formic acid without the need for amine bases as a product stabilizer is described. Complex 1 shows high catalytic productivity and activity. The dimethylsulfoxide (DMSO)/H2O medium is capable of stabilizing the reaction product thermodynamically, which was rationalized by DFT calculations.
Fluorine-Doped Antiperovskite Electrolyte for All-Solid-State Lithium-Ion Batteries
Higher conductivity: A fluorine-doped antiperovskite Li-ion conductor Li2(OH)0.9F0.1Cl shows electrochemical stability up to 9 V versus Li+/Li and two orders of magnitude higher Li-ion conductivity than that of orthorhombic Li2OHCl.
Rapid Access to Orthogonally Functionalized Naphthalenes: Application to the Total Synthesis of the Anticancer Agent Chartarin
Substituted naphthalenes: Orthogonally functionalized naphthalenes were synthesized from commercially available indanones in four steps. The developed method proceeds through the thermally induced fragmentation of cyclopropane indanones and involves a regioselective 1,2-chloride shift. This transformation enables the synthesis of the anticancer agent chartarin.
Low-Energy Electron-Induced Transformations in Organolead Halide Perovskite
Explaining the break-up: Low-energy electrons (4.5 to 60 eV) can affect structural and chemical properties of methylammonium (MA) lead iodide perovskite (MAPbI3) via interactions with the organic part. This results in MAPbI3 decomposition and aggregation of the hydrocarbon layer.
C−H Bond Formylation
Photo-induced Substitutive Introduction of the Aldoxime Functional Group to Carbon Chains: A Formal Formylation of Non-Acidic C(sp3)−H Bonds
Formally formyl: A photo-induced substitutive introduction of an aldoxime functional group to carbon chains was achieved using photo-excited 4-benzoylpyridine and arylsulfonyl oxime. This is a newly developed method for formal formylation of non-acidic C(sp3)−H bonds in a single step that proceeds at room temperature under neutral conditions.
Extended Aromatic Structure
Extended Bis(benzothia)quinodimethanes and Their Dications: From Singlet Diradicaloids to Isoelectronic Structures of Long Acenes
Isoelectronic to acenes: Extended bis(benzothia)quinodimethanes show increased diradical character with increasing molecular length. More importantly, their dications exhibit similar electronic structures to their corresponding all-carbon acene analogues and can be regarded as being genuine isoelectronic analogues of acenes.
Unidirectional Threading into a Bowl-Shaped Macrocyclic Trimer of Boron–Dipyrrin Complexes through Multipoint Recognition
Going in to bowl: A bowl-shaped macrocyclic trimer of a boron–dipyrrin complex has been synthesized in which six polarized B−F bonds are directed towards the center of the macrocycle for strong recognition. Cationic ammonium guests are strongly captured from the convex side of the macrocycle by hydrogen bonding, Coulomb forces, and C−H⋅⋅⋅π interactions and thread unidirectionally through the complex.
Tuning the Reactivity of Ultrathin Oxides: NO Adsorption on Monolayer FeO(111)
Tailored chemisorption: Supported oxide monolayers exhibit novel chemical properties that can be exploited for applications in catalysis. Drastic differences in adsorption of NO on supported FeO monolayers are observed, depending on the metal substrate. These differences are found to result from steric blocking, which is due to substrate-induced buckling of the FeO films.
Flexible Zirconium Metal-Organic Frameworks as Bioinspired Switchable Catalysts
An open and shut case: The inherent cavities and dynamic behavior of flexible MOFs, bear a close resemblance to regulatory enzymes. Switchable activation and deactivation of their catalytic properties occurs on pore opening and closing by solvation/solvent removal.
Spatially Separated Photosystem II and a Silicon Photoelectrochemical Cell for Overall Water Splitting: A Natural–Artificial Photosynthetic Hybrid
A hybrid natural–artificial photosynthetic platform was constructed by wiring photosystem II and a silicon photoelectrochemical cell based on a photocatalytic–photoelectrochemical Z-scheme design. The hybrid platform combined the strengths of natural and artificial platforms and achieved unassisted and spatially separated production of H2 and O2 from water splitting under solar irradiation.
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.
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.
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.
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.
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.
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.
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.
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.
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 %.
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.
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).
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.
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.
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.
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.
C−H Bond Activation
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.