The 100 most-cited articles in Angewandte Chemie, 2017

Abstract The development of low‐cost, efficient, and stable electrocatalysts for the oxygen reduction reaction (ORR) is desirable but remains a great challenge. Herein, we made a highly reactive and stable isolated single‐atom Fe/N‐doped porous carbon (ISA Fe/CN) catalyst with Fe loading up to 2.16 wt %. The catalyst showed excellent ORR performance with a half‐wave potential (E1/2) of 0.900 V, which outperformed commercial Pt/C and most non‐precious‐metal catalysts reported to date. Besides exceptionally high kinetic current density (Jk) of 37.83 mV cm−2 at 0.85 V, it also had a good methanol tolerance and outstanding stability. Experiments demonstrated that maintaining the Fe as isolated atoms and incorporating nitrogen was essential to deliver the high performance. First principle calculations further attributed the high reactivity to the high efficiency of the single Fe atoms in transporting electrons to the adsorbed OH species.

Abstract Metal–organic framework (MOF) nanosheets could serve as ideal building blocks of molecular sieve membranes owing to their structural diversity and minimized mass‐transfer barrier. To date, discovery of appropriate MOF nanosheets and facile fabrication of high performance MOF nanosheet‐based membranes remain as great challenges. A modified soft‐physical exfoliation method was used to disintegrate a lamellar amphiprotic MOF into nanosheets with a high aspect ratio. Consequently sub‐10 nm‐thick ultrathin membranes were successfully prepared, and these demonstrated a remarkable H 2 /CO 2 separation performance, with a separation factor of up to 166 and H 2 permeance of up to 8×10 −7 mol m −2 s −1 Pa −1 at elevated testing temperatures owing to a well‐defined size‐exclusion effect. This nanosheet‐based membrane holds great promise as the next generation of ultrapermeable gas separation membrane.

Abstract The design of active, selective, and stable CO 2 reduction electrocatalysts is still challenging. A series of atomically dispersed Co catalysts with different nitrogen coordination numbers were prepared and their CO 2 electroreduction catalytic performance was explored. The best catalyst, atomically dispersed Co with two‐coordinate nitrogen atoms, achieves both high selectivity and superior activity with 94 % CO formation Faradaic efficiency and a current density of 18.1 mA cm −2 at an overpotential of 520 mV. The CO formation turnover frequency reaches a record value of 18 200 h −1 , surpassing most reported metal‐based catalysts under comparable conditions. Our experimental and theoretical results demonstrate that lower a coordination number facilitates activation of CO 2 to the CO 2 .− intermediate and hence enhances CO 2 electroreduction activity.

Abstract DNA‐based machines have attracted rapidly growing interest owing to their potential in drug delivery, biocomputing, and diagnostic applications. Herein, we report a type of exonuclease III (Exo III)‐powered stochastic DNA walker that can autonomously move on a spherical nucleic acid (SNA)‐based 3D track. The motion is propelled by unidirectional Exo III digestion of hybridized DNA tracks in a burnt‐bridge mechanism. The operation of this Exo III‐propelled DNA walker was monitored in real time and at the single‐particle resolution using total internal reflection fluorescence microscopy (TIRF). We further interrogated the morphological effect of the 3D track on the nuclease activity, which suggested that the performance of the DNA walker was critically dependent upon the DNA density and the track conformation. Finally, we demonstrated potential bioanalytical applications of this SNA‐based stochastic DNA walker by exploiting movement‐triggered cascade signal amplification.

Abstract Das Activation‐Strain‐ oder Distortion/Interaction‐Modell ist ein Instrument zur Analyse von Aktivierungsbarrieren und damit von Reaktionsgeschwindigkeiten. Für eine bimolekulare Reaktion ergibt sich die Aktivierungsenergie aus der Summe der Energien, die für die Deformation der Grundzustandsgeometrie der Reaktanten benötigt wird, um die Geometrie des Übergangszustands anzunehmen, plus der Wechselwirkungsenergie zwischen diesen deformierten Reaktanten. Die mit der Deformation assoziierte Energie wird “activation strain” (Aktivierungsspannung) oder “distortion energy” (Deformationsenergie) genannt. Diese Energie bildet den Hauptbeitrag zur Aktivierungsbarriere. Der Übergangszustand wird erreicht, wenn die stabilisierende Wechselwirkung die Aktivierungsspannung überwindet. Die Verlaufsanalyse dieser Energien gibt Einblicke in die reaktivitätsbestimmenden physikalischen Faktoren. Anwendungsbeispiele für das Modell sind die Analyse von Substitutions‐ und Eliminierungsreaktionen sowie Cycloadditionen.

Abstract Lithium (Li) metal is the most promising electrode for next‐generation rechargeable batteries. However, the challenges induced by Li dendrites on a working Li metal anode hinder the practical applications of Li metal batteries. Herein, nitrogen (N) doped graphene was adopted as the Li plating matrix to regulate Li metal nucleation and suppress dendrite growth. The N‐containing functional groups, such as pyridinic and pyrrolic nitrogen in the N‐doped graphene, are lithiophilic, which guide the metallic Li nucleation causing the metal to distribute uniformly on the anode surface. As a result, the N‐doped graphene modified Li metal anode exhibits a dendrite‐free morphology during repeated Li plating and demonstrates a high Coulombic efficiency of 98 % for near 200 cycles.

Abstract Ein Kennzeichen der seit 2005 bekannten cyclischen Alkylaminocarbene (CAACs) ist ihre ausgeprägte Nucleophilie (σ‐Donor) und zugleich Elektrophile (π‐Akzeptor). Diese Eigenschaften ermöglichen die Aktivierung einer Vielzahl kleiner Moleküle und starker Bindungen, die Stabilisierung hochreaktiver dia‐ und paramagnetischer Spezies der Haupt‐ und Nebengruppenelemente sowie die Bildung stabiler Bindungen mit Metallen, was zu robusten Katalysatoren führt. Dieser Aufsatz fasst die wichtigsten Ergebnisse vor 2014 kurz zusammen, wobei der Schwerpunkt jedoch auf den Erkenntnissen der vergangenen drei Jahre liegt.

Abstract Polymeric or organic semiconductors are promising candidates for photocatalysis but mostly only show moderate activity owing to strongly bound excitons and insufficient optical absorption. Herein, we report a facile bottom‐up strategy to improve the activity of a carbon nitride to a level in which a majority of photons are really used to drive photoredox chemistry. Co‐condensation of urea and oxamide followed by post‐calcination in molten salt is shown to result in highly crystalline species with a maximum π–π layer stacking distance of heptazine units of 0.292 nm, which improves lateral charge transport and interlayer exciton dissociation. The addition of oxamide decreases the optical band gap from 2.74 to 2.56 eV, which enables efficient photochemistry also with green light. The apparent quantum yield (AQY) for H 2 evolution of optimal samples reaches 57 % and 10 % at 420 nm and 525 nm, respectively, which is significantly higher than in most previous experiments.

Abstract Electrochemical reduction of CO2 to ethanol, a clean and renewable liquid fuel with high heating value, is an attractive strategy for global warming mitigation and resource utilization. However, converting CO2 to ethanol remains great challenge due to the low activity, poor product selectivity and stability of electrocatalysts. Here, the B‐ and N‐co‐doped nanodiamond (BND) was reported as an efficient and stable electrode for selective reduction of CO2 to ethanol. Good ethanol selectivity was achieved on the BND with high Faradaic efficiency of 93.2 % (−1.0 V vs. RHE), which overcame the limitation of low selectivity for multicarbon or high heating value fuels. Its superior performance was mainly originated from the synergistic effect of B and N co‐doping, high N content and overpotential for hydrogen evolution. The possible pathway for CO2 reduction revealed by DFT computation was CO2→*COOH→*CO→*COCO→*COCH2OH→*CH2OCH2OH→CH3CH2OH.

Abstract Hollow nanostructures have attracted increasing research interest in electrochemical energy storage and conversion owing to their unique structural features. However, the synthesis of hollow nanostructured metal phosphides, especially nonspherical hollow nanostructures, is rarely reported. Herein, we develop a metal–organic framework (MOF)‐based strategy to synthesize carbon incorporated Ni–Co mixed metal phosphide nanoboxes (denoted as NiCoP/C). The oxygen evolution reaction (OER) is selected as a demonstration to investigate the electrochemical performance of the NiCoP/C nanoboxes. For comparison, Ni–Co layered double hydroxide (Ni–Co LDH) and Ni–Co mixed metal phosphide (denoted as NiCoP) nanoboxes have also been synthesized. Benefiting from their structural and compositional merits, the as‐synthesized NiCoP/C nanoboxes exhibit excellent electrocatalytic activity and long‐term stability for OER.

Abstract The discovery of new nonlinear optical (NLO) materials for coherent light generation in the deep‐ultraviolet (DUV, wavelength below 200 nm) region is essential for the development of laser technologies. Herein, we report a new material CsB 4 O 6 F (CBF), which combines the superior structural properties of two well‐known NLO materials, β‐BaB 2 O 4 (BBO) and KBe 2 BO 3 F 2 (KBBF). CBF exhibits excellent DUV optical properties including a short cutoff edge (155 nm), a large SHG response (≈1.9×KDP), and a suitable birefringence that enables frequency doubling down to 171.6 nm. Remarkably, CBF melts congruently and shows an improved growth habit. In addition, our rational design strategy will contribute to the discovery of DUV NLO materials.

Abstract Extending the conjugation of viologen by a planar thiazolo[5,4‐d]thiazole (TTz) framework and functionalizing the pyridinium with hydrophilic ammonium groups yielded a highly water‐soluble π‐conjugation extended viologen, 4,4′‐(thiazolo[5,4‐d]thiazole‐2,5‐diyl)bis(1‐(3‐(trimethylammonio)propyl)pyridin‐1‐ium) tetrachloride, [(NPr)2TTz]Cl4 , as a novel two‐electron storage anolyte for aqueous organic redox flow battery (AORFB) applications. Its physical and electrochemical properties were systematically investigated. Paired with 4‐trimethylammonium‐TEMPO (NMe‐TEMPO) as catholyte, [(NPr)2TTz]Cl4 enables a 1.44 V AORFB with a theoretical energy density of 53.7 Wh L−1. A demonstrated [(NPr)2TTz]Cl4/NMe‐TEMPO AORFB delivered an energy efficiency of 70 % and 99.97 % capacity retention per cycle.

Die Chemie begrüßt eine neue Bindung: Die mechanische Bindung stattet Moleküle mit Komponenten aus, deren Bewegung gesteuert und verfolgt werden kann. J. F. Stoddart beschreibt in seinem Nobelaufsatz, wie die Fähigkeit zum gezielten Aufbau mechanisch verzahnter Moleküle zum Design und der Synthese von Shuttles, Schaltern und Maschinen auf der Nanoskala geführt hat.

Abstract Metal–organic frameworks (MOFs) are a class of promising materials for diverse heterogeneous catalysis, but they are usually not directly employed for oxygen evolution electrocatalysis. Most reports focus on using MOFs as templates to in situ create efficient electrocatalysts through annealing. Herein, we prepared a series of Fe/Ni‐based trimetallic MOFs (Fe/Ni/Co(Mn)‐MIL‐53 accordingly to the Material of Institute Lavoisier) by solvothermal synthesis, which can be directly adopted as highly efficient electrocatalysts. The Fe/Ni/Co(Mn)‐MIL‐53 shows a volcano‐type oxygen evolution reaction (OER) activity as a function of compositions. The optimized Fe/Ni 2.4 /Co 0.4 ‐MIL‐53 can reach a current density of 20 mA cm −2 at low overpotential of 236 mV with a small Tafel slope of 52.2 mV dec −1 . In addition, the OER performance of these MOFs can be further enhanced by directly being grown on nickel foam (NF).

Abstract We successfully prepared QDs incorporated into a silica/alumina monolith (QDs‐SAM) by a simple sol–gel reaction of an Al–Si single precursor with CsPbBr3 QDs blended in toluene solution, without adding water and catalyst. The resultant transparent monolith exhibits high photoluminescence quantum yields (PLQY) up to 90 %, and good photostability under strong illumination of blue light for 300 h. We show that the preliminary ligand exchange of didodecyl dimethyl ammonium bromide (DDAB) was very important to protect CsPbBr3 QDs from surface damages during the sol–gel reaction, which not only allowed us to maintain the original optical properties of CsPbBr3 QDs but also prevented the aggregation of QDs and made the monolith transparent. The CsPbBr3 QDs‐SAM in powder form was easily mixed into the resins and applied as color‐converting layer with curing on blue light‐emitting diodes (LED). The material showed a high luminous efficacy of 80 lm W−1 and a narrow emission with a full width at half maximum (FWHM) of 25 nm.

Abstract Das Gebiet der molekularen Maschinen nahm seinen Anfang, nachdem mehreren Forschungsgruppen die relativ einfache Herstellung ineinander verschlungener Ringverbindungen gelungen war. Man unterscheidet hier Catenane, als ineinander verschlungene Ringe, und Rotaxane, bei denen Ringe auf molekulare Fasern oder Achsen aufgefädelt sind. Andere Familien von molekularen Maschinen wurden ebenfalls entwickelt, die nicht in den Bereich der Catenane oder Rotaxane gehören, diese stammen aber erst aus jüngerer Zeit. Da die Erzeugung ineinander verschlungener Ringmoleküle mit Blick auf das Gebiet der molekularen Maschinen so wichtig ist, werden wir mit diesem Teil unserer Arbeiten beginnen. Der zweite Teil wird sich den dynamischen Eigenschaften solcher Systeme widmen, sowie den Verbindungen, deren Bewegung auf kontrollierte Weise “von außen” gesteuert werden kann, d. h. den molekularen Maschinen. Wir werden unsere Ausführungen auf eine sehr begrenzte Auswahl von Beispielen beschränken, die wir als besonders repräsentativ für das Forschungsgebiet erachten.

Abstract Abstraction of a chloride ligand from the dysprosium metallocene [(Cpttt)2DyCl] (1Dy Cpttt=1,2,4‐tri(tert‐butyl)cyclopentadienide) by the triethylsilylium cation produces the first base‐free rare‐earth metallocenium cation [(Cpttt)2Dy]+ (2Dy) as a salt of the non‐coordinating [B(C6F5)4]− anion. Magnetic measurements reveal that [2Dy][B(C6F5)4] is an SMM with a record anisotropy barrier up to 1277 cm−1 (1837 K) in zero field and a record magnetic blocking temperature of 60 K, including hysteresis with coercivity. The exceptional magnetic axiality of 2Dy is further highlighted by computational studies, which reveal this system to be the first lanthanide SMM in which all low‐lying Kramers doublets correspond to a well‐defined MJ value, with no significant mixing even in the higher doublets.

Abstract Funktionalisierungen von C(sp3)‐H‐Bindungen verkürzen und vereinfachen chemische Synthesen, indem sie die Verwendung einfacher Moleküle ermöglichen und neuartige Retrosynthesen bereitstellen. Intensive Forschungen, die auf die Entwicklung neuer Reaktionen basierend auf dem Ansatz der C‐H‐Funktionalisierung abzielten, haben zur weiten Verbreitung dieser Methoden in einer Vielzahl von Bereichen geführt. Dieser Aufsatz erörtert die Stärken und Schwächen der drei Hauptstrategien – übergangsmetallkatalysierte C‐H‐Aktivierung, 1,n‐Wasserstoffatomtransfer und übergangsmetallkatalysierter Carben‐ oder Nitrentransfer – in der gezielten Funktionalisierung nichtaktivierter C(sp3)‐H‐Bindungen. Für jede Strategie werden der Anwendungsbereich, die Reaktivität verschiedener C‐H‐Bindungen, die Position der reagierenden C‐H‐Bindungen bezüglich der dirigierenden Gruppe und die stereochemischen Auswirkungen mit Beispielen aus der Literatur veranschaulicht. Das Ziel dieses Aufsatzes ist es, dem Anwender von C‐H‐Funktionalisierungsreaktionen eine Orientierungshilfe zu geben und künftige…

Abstract Structural parameters of ternary transition‐metal dichalcogenide (TMD) alloy usually obey Vegard law well, while interestingly it often exhibits boosted electrocatalytic performances relative to its two pristine binary TMDs. To unveil the underlying reasons, we propose an ideal model of ternary TMDs alloy monolayer. As a prototype, MoSeS alloy monolayers are successfully synthesized, in which X‐ray absorption fine structure spectroscopy manifests their shortened Mo−S and lengthened Mo−Se bonds, helping to tailor the d‐band electronic structure of Mo atoms. Density functional theory calculations illustrate an increased density of states near their conduction band edge, which ensures faster electron transfer confirmed by their lower work function and smaller charge‐transfer resistance. Energy calculations show the off‐center charge around Mo atoms not only benefits for stabilizing COOH* intermediate confirmed by its most negative formation energy, but also facilitates the rate‐limiting CO desorption step verified by CO temperature programmed desorption and electro‐stripping…

Abstract Herein we report the colloidal synthesis of Cs3Sb2I9 and Rb3Sb2I9 perovskite nanocrystals, and explore their potential for optoelectronic applications. Different morphologies, such as nanoplatelets and nanorods of Cs3Sb2I9, and spherical Rb3Sb2I9 nanocrystals were prepared. All these samples show band‐edge emissions in the yellow–red region. Exciton many‐body interactions studied by femtosecond transient absorption spectroscopy of Cs3Sb2I9 nanorods reveals characteristic second‐derivative‐type spectral features, suggesting red‐shifted excitons by as much as 79 meV. A high absorption cross‐section of ca. 10−15 cm2 was estimated. The results suggest that colloidal Cs3Sb2I9 and Rb3Sb2I9 nanocrystals are potential candidates for optical and optoelectronic applications in the visible region, though a better control of defect chemistry is required for efficient applications.

Abstract Nanomaterials with enzyme‐like activities (nanozymes) attracts significant interest due to their therapeutic potential for the treatment of various diseases. Herein, we report that a Mn 3 O 4 nanozyme functionally mimics three major antioxidant enzymes, that is, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and the multienzyme activity is size as well as morphology‐dependent. The redox modulatory effect of Mn 3 O 4 plays a crucial role in protecting the cells from MPP+ induced cytotoxicity in a Parkinson disease (PD)‐like cellular model, indicating that manganese‐based nanomaterials having multi‐enzyme activity can robustly rescue the cells from oxidative damage and thereby possess therapeutic potential to prevent ROS‐mediated neurological disorders.

Abstract Die mobile und stationäre Energiespeicherung durch wiederaufladbare Batterien ist ein Thema von breiter gesellschaftlicher und ökonomischer Bedeutung. Die wichtigste Technologie in diesem Bereich ist die Lithiumionenbatterie (LIB), jedoch muss man davon ausgehen, dass ein massiv wachsender LIB‐Markt ernsten Druck auf Ressourcen und Lieferketten ausüben wird. Seit kurzem richtet sich die Aufmerksamkeit daher auch wieder auf die Natriumionenbatterie (SIB), die eine preisgünstige Alternative darstellen könnte, die weniger anfällig für Ressourcen‐ und Versorgungsrisiken ist. Auf dem Papier scheint der Austausch von Lithium durch Natrium in einer Batterie unkompliziert, jedoch erlebt man in der Praxis oft unvorhersehbare Überraschungen. Was geschieht, wenn in Elektrodenreaktionen Lithium durch Natrium ersetzt wird? Dieser Aufsatz bietet einen aktuellen Überblick über das Redoxverhalten von Materialien bei ihrer Verwendung als Elektroden in LIBs bzw. SIBs. Die Vorteile und Herausforderungen im Zusammenhang mit der Verwendung von Natrium anstelle von Lithium werden diskutiert.

Abstract Persistent room‐temperature phosphorescence (RTP) in pure organic materials has attracted great attention because of their unique optical properties. The design of organic materials with bright red persistent RTP remains challenging. Herein, we report a new design strategy for realizing high brightness and long lifetime of red‐emissive RTP molecules, which is based on introducing an alkoxy spacer between the hybrid units in the molecule. The spacer offers easy Br−H bond formation during crystallization, which also facilitates intermolecular electron coupling to favor persistent RTP. As the majority of RTP compounds have to be confined in a rigid environment to quench nonradiative relaxation pathways for bright phosphorescence emission, nanocrystallization is used to not only rigidify the molecules but also offer the desirable size and water‐dispersity for biomedical applications.

Abstract Two types of templates, an active metal salt and silica nanoparticles, are used concurrently to achieve the facile synthesis of hierarchical meso/microporous FeCo‐Nx‐carbon nanosheets (meso/micro‐FeCo‐Nx‐CN) with highly dispersed metal sites. The resulting meso/micro‐FeCo‐Nx‐CN shows high and reversible oxygen electrocatalytic performances for both ORR and OER, thus having potential for applications in rechargeable Zn–air battery. Our approach creates a new pathway to fabricate 2D meso/microporous structured carbon architectures for bifunctional oxygen electrodes in rechargeable Zn–air battery as well as opens avenues to the scale‐up production of rationally designed heteroatom‐doped catalytic materials for a broad range of applications.

Abstract Despite its widespread use in signal collection, flexible sensors have been rarely used in human–machine interactions owing to its indistinguishable signal, poor reliability, and poor stability when inflicted with unavoidable scratches and/or mechanical cuts. A highly sensitive and self‐healing sensor enabled by multiple hydrogen bonding network and nanostructured conductive network is demonstrated. The nanostructured supramolecular sensor displays extremely fast (ca. 15 s) and repeatable self‐healing ability with high healing efficiency (93 % after the third healing process). It can precisely detect tiny human motions, demonstrating highly distinguishable and reliable signals even after cutting–healing and bending over 20 000 cycles. Furthermore, a human–machine interaction system is integrated to develop a facial expression control system and an electronic larynx, aiming to control the robot to assist the patient's daily life and help the mute to realize real‐time speaking.

Abstract Carbon dioxide and carbon monoxide can be electrochemically reduced to useful products such as ethylene and ethanol on copper electrocatalysts. The process is yet to be optimized and the exact mechanism and the corresponding reaction intermediates are under debate or unknown. In particular, it has been hypothesized that the C−C bond formation proceeds via CO dimerization and further hydrogenation. Although computational support for this hypothesis exists, direct experimental evidence has been elusive. In this work, we detect a hydrogenated dimer intermediate (OCCOH) using Fourier transform infrared spectroscopy at low overpotentials in LiOH solutions. Density functional theory calculations support our assignment of the observed vibrational bands. The formation of this intermediate is structure sensitive, as it is observed only during CO reduction on Cu(100) and not on Cu(111), in agreement with previous experimental and computational observations.

Abstract A family of perovskite light absorbers (NH 4 ) 3 Sb 2 I x Br 9− x (0≤ x ≤9) was prepared. These materials show good solubility in ethanol, a low‐cost, hypotoxic, and environmentally friendly solvent. The light absorption of (NH 4 ) 3 Sb 2 I x Br 9− x films can be tuned by adjusting I and Br content. The absorption onset for (NH 4 ) 3 Sb 2 I x Br 9− x films changes from 558 nm to 453 nm as x changes from 9 to 0. (NH 4 ) 3 Sb 2 I 9 single crystals were prepared, exhibiting a hole mobility of 4.8 cm 2 V −1 s −1 and an electron mobility of 12.3 cm 2 V −1 s −1 . (NH 4 ) 3 Sb 2 I 9 solar cells gave an open‐circuit voltage of 1.03 V and a power conversion efficiency of 0.51 %.

Abstract Tuning the surface strain of heterogeneous catalysts represents a powerful strategy to engineer their catalytic properties by altering the electronic structures. However, a clear and systematic understanding of strain effect in electrochemical reduction of carbon dioxide is still lacking, which restricts the use of surface strain as a tool to optimize the performance of electrocatalysts. Herein, we demonstrate the strain effect in electrochemical reduction of CO 2 by using Pd octahedra and icosahedra with similar sizes as a well‐defined platform. The Pd icosahedra/C catalyst shows a maximum Faradaic efficiency for CO production of 91.1 % at −0.8 V versus reversible hydrogen electrode (vs. RHE), 1.7‐fold higher than the maximum Faradaic efficiency of Pd octahedra/C catalyst at −0.7 V (vs. RHE). The combination of molecular dynamic simulations and density functional theory calculations reveals that the tensile strain on the surface of icosahedra boosts the catalytic activity by shifting up the d ‐band center and thus strengthening the adsorption of key intermediate COOH*.…

Abstract A novel OER electrocatalyst, namely oxygen‐incorporated amorphous cobalt sulfide porous nanocubes (A‐CoS 4.6 O 0.6 PNCs), show advantages over the benchmark RuO 2 catalyst in alkaline/neutral medium. Experiments combining with calculation demonstrate that the desirable O* adsorption energy, associated with the distorted CoS 4.6 O 0.6 octahedron structure and the oxygen doping, contribute synergistically to the outstanding electrocatalytic activity.

Eine Reise in die Nanowelt: Die Fähigkeit, motorartige Funktionen auf molekularer Ebene zu entwickeln und zu nutzen, bereitet die Grundlage für zahlreiche dynamische molekulare Systeme. B. L. Feringa schildert in seinem Nobel-Aufsatz den Werdegang des Gebiets der molekularen Motoren und erläutert, wie Moleküle durch den Einbau von responsiven und adaptiven Eigenschaften programmiert und ihre Bewegung gesteuert werden kann.

Abstract The nanostructure of a series of choline chloride/urea/water deep eutectic solvent mixtures was characterized across a wide hydration range by neutron total scattering and empirical potential structure refinement (EPSR). As the structure is significantly altered, even at low hydration levels, reporting the DES water content is important. However, the DES nanostructure is retained to a remarkably high level of water (ca. 42 wt % H2O) because of solvophobic sequestration of water into nanostructured domains around cholinium cations. At 51 wt %/83 mol % H2O, this segregation becomes unfavorable, and the DES structure is disrupted; instead, water–water and DES–water interactions dominate. At and above this hydration level, the DES–water mixture is best described as an aqueous solution of DES components.

Abstract Pd‐catalyzed intramolecular asymmetric carbopalladation of N‐aryl acrylamides followed by reduction of C(sp3)‐Pd intermediate using diboron–water as a hydride source afforded enantioenriched 3,3‐disubstituted oxindoles in high yields and enantioselectivities. When heavy water was used as a deuterium donor in combination with bis(catecholato)diboron (Cat2B2), deuterium was incorporated into the products with high synthetic efficiency. The ligand determined both the enantioselectivity of the reaction and the reaction pathways, thereby affording either hydroarylation (reductive Heck) or carboborylation products.

Abstract BiVO 4 films with (040) facet grown vertically on fluorine doped SnO 2 (FTO) glass substrates are prepared by a seed‐assisted hydrothermal method. A simple electrochemical treatment process drastically enhances the photocatalytic activity of BiVO 4 , exhibiting a remarkable photocurrent density of 2.5 mA cm −2 at 1.23 V vs. reversible hydrogen electrode (RHE) under AM 1.5 G illumination, which is approximately 10‐fold higher than that of the pristine photoanode. Loading cobalt borate (CoBi) as cocatalyst, the photocurrent density of the BiVO 4 photoanode can be further improved to 3.2 mA cm −2 , delivering an applied bias photon‐to‐current efficiency (ABPE) of 1.1 %. Systematic studies reveal that crystal facet orientation also synergistically boosts both charge separation and transfer efficiencies, resulting in remarkably enhanced photocurrent densities. These findings provide a facile and effective approach for the development of efficient photoelectrodes for photoelectrochemical water splitting.

Abstract A stimuli‐responsive lanthanide‐based smart nanocomposite has been fabricated by supramolecular assembly and applied as an active material in multidimensional memory materials. Conjugation of the lanthanide complexes with carbon dots provides a stimuli response that is based on the modulation of the energy level of the ligand and affords microsecond‐to‐nanosecond fluorescence lifetimes, giving rise to intriguing memory performance in the spatial and temporal dimension. The present study points to a new direction for the future development of multidimensional memory materials based on inorganic–organic hybrid nanosystems.

Abstract Two new bithiophene imide (BTI)‐based n‐type polymers were synthesized. f‐BTI2‐FT based on a fused BTI dimer showed a smaller band gap, a lower LUMO, and higher crystallinity than s‐BTI2‐FT containing a BTI dimer connected through a single bond. s‐BTI2‐FT exhibited a remarkable electron mobility of 0.82 cm2 V−1 s−1, and f‐BTI2‐FT showed a further improved mobility of 1.13 cm2 V−1 s−1 in transistors. When blended with the polymer donor PTB7‐Th, f‐BTI2‐FT‐based all‐polymer solar cells (all‐PSCs) attained a PCE of 6.85 %, the highest value for an all‐PSC not based on naphthalene (or perylene) diimide polymer acceptors. However, s‐BTI2‐FT all‐PSCs showed nearly no photovoltaic effect. The results demonstrate that f‐BTI2‐FT is one of most promising n‐type polymers and that ring fusion offers an effective approach for designing polymers with improved electrical properties.

Abstract An active and stable photocatalyst to directly split water is desirable for solar‐energy conversion. However, it is difficult to accomplish overall water splitting without sacrificial electron donors. Herein, we demonstrate a strategy via constructing a single site to simultaneously promote charge separation and catalytic activity for robust overall water splitting. A single Co1‐P4 site confined on g‐C3N4 nanosheets was prepared by a facile phosphidation method, and identified by electron microscopy and X‐ray absorption spectroscopy. This coordinatively unsaturated Co site can effectively suppress charge recombination and prolong carrier lifetime by about 20 times relative to pristine g‐C3N4, and boost water molecular adsorption and activation for oxygen evolution. This single‐site photocatalyst exhibits steady and high water splitting activity with H2 evolution rate up to 410.3 μmol h−1 g−1, and quantum efficiency as high as 2.2 % at 500 nm.

Abstract Cyclopentadienyl (Cp) ligands enable efficient steering of various transition‐metal‐catalyzed transformations, in particular enantioselective C−H activation. Currently only few chiral Cp ligands are available. Therefore, a conceptually general approach to chiral Cp ligand discovery would be invaluable as it would enable the discovery of applicable Cp ligands and to efficiently and rapidly vary and tune their structures. Herein, we describe the three‐step gram‐scale synthesis of a structurally diverse and widely applicable chiral Cp ligand collection (JasCp ligands) with highly variable and adjustable structures. Their modular nature and their amenability to rapid structure variation enabled the efficient discovery of ligands for three enantioselective RhIII‐catalyzed C−H activation reactions, including one unprecedented transformation. This novel approach should enable the discovery of efficient chiral Cp ligands for various further enantioselective transformations.

Abstract A one‐step ligand‐free method based on an adsorption–precipitation process was developed to fabricate iridium/cerium oxide (Ir/CeO 2 ) nanocatalysts. Ir species demonstrated a strong metal–support interaction (SMSI) with the CeO 2 substrate. The chemical state of Ir could be finely tuned by altering the loading of the metal. In the carbon dioxide (CO 2 ) hydrogenation reaction it was shown that the chemical state of Ir species—induced by a SMSI—has a major impact on the reaction selectivity. Direct evidence is provided indicating that a single‐site catalyst is not a prerequisite for inhibition of methanation and sole production of carbon monoxide (CO) in CO 2 hydrogenation. Instead, modulation of the chemical state of metal species by a strong metal–support interaction is more important for regulation of the observed selectivity (metallic Ir particles select for methane while partially oxidized Ir species select for CO production). The study provides insight into heterogeneous catalysts at nano, sub‐nano, and atomic scales.

Abstract Lithium (Li) metal is a promising anode material for high‐energy density batteries. However, the unstable and static solid electrolyte interphase (SEI) can be destroyed by the dynamic Li plating/stripping behavior on the Li anode surface, leading to side reactions and Li dendrites growth. Herein, we design a smart Li polyacrylic acid (LiPAA) SEI layer high elasticity to address the dynamic Li plating/stripping processes by self‐adapting interface regulation, which is demonstrated by in situ AFM. With the high binding ability and excellent stability of the LiPAA polymer, the smart SEI can significantly reduce the side reactions and improve battery safety markedly. Stable cycling of 700 h is achieved in the LiPAA‐Li/LiPAA‐Li symmetrical cell. The innovative strategy of self‐adapting SEI design is broadly applicable, providing opportunities for use in Li metal anodes

Abstract Der nachhaltige Umgang mit den Ressourcen unseres Planeten ist essenziell. Edelmetalle sind sehr selten und werden vielfältig in Schlüsseltechnologien wie der Katalyse genutzt. Mangan ist das dritthäufigste Übergangsmetall der Erdkruste und aufgrund seiner kürzlich entdeckten beeindruckenden Reaktivität für Hydrierungen und Dehydrierungen ein potenzieller Edelmetall‐“Ersatz”. An einen derartigen “Ersatz” sind auch Hoffnungen auf neuartige Selektivitätsprofile geknüpft, die mit Edelmetallen nicht erzielt werden können. Dass Mangankomplexe eine solche Reaktivität für (De)Hydrierungen aufweisen, wurde erstmals 2016 gezeigt. Hier fassen wir die seitdem publizierten Arbeiten auf diesem Gebiet zusammen und diskutieren im Besonderen die Bedeutung der Mangankatalysatoren im Vergleich zu Cobalt‐ und Eisenkatalysatoren.

Abstract Wasserstoffisotope sind einzigartige Werkzeuge zur Identifizierung und Erforschung biologischer oder chemischer Vorgänge. Wasserstoffisotopenmarkierungen erlauben den spurlosen und direkten Einbau einer zusätzlichen Masseneinheit oder eines radioaktiven Markers in ein organisches Molekül, und dies praktisch ohne Änderungen der chemischen Struktur, der physikalischen Eigenschaften oder der biologischen Aktivität. Die Verwendung von deuteriummarkierten Isotopologen zur Untersuchung der spezifischen massenspektrometrischen (MS) Muster, die von Gemischen biologisch relevanter Moleküle hervorgerufen werden, ermöglicht eine drastische Vereinfachung der Analyse. Solche Methoden ermöglichen nun tiefe Einblicke in einen großen, kontinuierlich anwachsenden Bereich von Anwendungen in den Biowissenschaften und darüber hinaus. Speziell Tritium ( 3 H) wird zunehmend eingesetzt, insbesondere in der pharmazeutischen Wirkstoffsuche. Aufwand und Kosten der Synthese markierter Verbindungen werden durch die hohe Empfindlichkeit der Analyse und hohe Zuverlässigkeit der erhaltenen Daten mehr als…

Abstract The utility of electronically conductive metal–organic frameworks (EC‐MOFs) in high‐performance devices has been limited to date by a lack of high‐quality thin film. The controllable thin‐film fabrication of an EC‐MOF, Cu3(HHTP)2, (HHTP=2,3,6,7,10,11‐hexahydroxytriphenylene), by a spray layer‐by‐layer liquid‐phase epitaxial method is reported. The Cu3(HHTP)2 thin film can not only be precisely prepared with thickness increment of about 2 nm per growing cycle, but also shows a smooth surface, good crystallinity, and high orientation. The chemiresistor gas sensor based on this high‐quality thin film is one of the best room‐temperature sensors for NH3 among all reported sensors based on various materials.

Abstract Z‐scheme water splitting is a promising approach based on high‐performance photocatalysis by harvesting broadband solar energy. Its efficiency depends on the well‐defined interfaces between two semiconductors for the charge kinetics and their exposed surfaces for chemical reactions. Herein, we report a facile cation‐exchange approach to obtain compounds with both properties without the need for noble metals by forming Janus‐like structures consisting of γ‐MnS and Cu7S4 with high‐quality interfaces. The Janus‐like γ‐MnS/Cu7S4 structures displayed dramatically enhanced photocatalytic hydrogen production rates of up to 718 μmol g−1 h−1 under full‐spectrum irradiation. Upon further integration with an MnOx oxygen‐evolution cocatalyst, overall water splitting was accomplished with the Janus structures. This work provides insight into the surface and interface design of hybrid photocatalysts, and offers a noble‐metal‐free approach to broadband photocatalytic hydrogen production.

Abstract Ammonia is synthesized directly from water and N2 at room temperature and atmospheric pressure in a flow electrochemical cell operating in gas phase (half‐cell for the NH3 synthesis). Iron supported on carbon nanotubes (CNTs) was used as the electrocatalyst in this half‐cell. A rate of ammonia formation of 2.2×10−3 g m−2 h−1 was obtained at room temperature and atmospheric pressure in a flow of N2, with stable behavior for at least 60 h of reaction, under an applied potential of −2.0 V. This value is higher than the rate of ammonia formation obtained using noble metals (Ru/C) under comparable reaction conditions. Furthermore, hydrogen gas with a total Faraday efficiency as high as 95.1 % was obtained. Data also indicate that the active sites in NH3 electrocatalytic synthesis may be associated to specific carbon sites formed at the interface between iron particles and CNT and able to activate N2, making it more reactive towards hydrogenation.

Abstract Die allmählich zunehmende Konzentration an Kohlendioxid (CO2) in der Atmosphäre wurde als Hauptursache für den Anstieg der mittleren Erdtemperatur erkannt. In den letzten Jahren hat daher die Entwicklung von Wegen zur hocheffizienten Umwandlung von CO2 viel Beachtung gefunden. Dieser Aufsatz beschreibt neueste Fortschritte auf dem Gebiet von Festkörperkatalysatoren für die elektrochemische CO2‐Reduktion. Die Bedeutung dieser katalytischen Verfahren wird im Einführungsteil dargestellt, darauf folgen die allgemeinen Parameter für die elektrochemische CO2‐Reduktion und ein Überblick zur Reaktionsvorrichtung. Wir erörtern außerdem verschiedene Arten von festen Katalysatoren in Abhängigkeit von den Mechanismen der CO2‐Umwandlung. Darüber hinaus geben wir eine Zusammenfassung zu den entscheidenden Faktoren (Partikelgröße, Oberflächenstruktur, Zusammensetzung usw.), die die Leistungsfähigkeit der elektrochemischen Reduktion bestimmen.

Abstract Hollow structures with an efficient light harvesting and tunable interior component offer great advantages for constructing a Z‐scheme system. Controlled design of hollow cobalt sulfide (Co9S8) cubes embedded with cadmium sulfide quantum dots (QDs) is described, using hollow Co(OH)2 as the template and a one‐pot hydrothermal strategy. The hollow CdS/Co9S8 cubes utilize multiple reflections of light in the cubic structure to achieve enhanced photocatalytic activity. Importantly, the photoexcited charge carriers can be effectively separated by the construction of a redox‐mediator‐free Z‐scheme system. The hydrogen evolution rate over hollow CdS/Co9S8 is 134 and 9.1 times higher than that of pure hollow Co9S8 and CdS QDs under simulated solar light irradiation, respectively. Moreover, this is the first report describing construction of a hollow Co9S8 based Z‐scheme system for photocatalytic water splitting, which gives full play to the advantages of light‐harvesting and charges separation.

Abstract Two‐dimensional (2D) materials are promising candidates for advanced water purification membranes. A new kind of lamellar membrane is based on a stack of 2D MXene nanosheets. Starting from compact Ti3AlC2, delaminated nanosheets of the composition Ti3C2Tx with the functional groups T (O, OH, and/or F) can be produced by etching and ultrasonication and stapled on a porous support by vacuum filtration. The MXene membrane supported on anodic aluminum oxide (AAO) substrate shows excellent water permeance (more than 1000 L m−2 h−1 bar−1) and favorable rejection rate (over 90 %) for molecules with sizes larger than 2.5 nm. The water permeance through the MXene membrane is much higher than that of the most membranes with similar rejections. Long‐time operation also reveals the outstanding stability of the MXene membrane for water purification.

Abstract Layered double hydroxides (LDHs) with two‐dimensional lamellar structures show excellent electrocatalytic properties. However, the catalytic activity of LDHs needs to be further improved as the large lateral size and thickness of the bulk material limit the number of exposed active sites. However, the development of efficient strategies to exfoliate bulk LDHs into stable monolayer LDH nanosheets with more exposed active sites is very challenging. On the other hand, the intrinsic activity of monolayer LDH nanosheets can be tuned by surface engineering. Herein, we have exfoliated bulk CoFe LDHs into ultrathin LDH nanosheets through Ar plasma etching, which also resulted in the formation of multiple vacancies (including O, Co, and Fe vacancies) in the ultrathin 2D nanosheets. Owing to their ultrathin 2D structure, the LDH nanosheets expose a greater number of active sites, and the multiple vacancies significantly improve the intrinsic activity in the oxygen evolution reaction (OER).

Abstract The first example of a heterogeneous iron(III)‐catalyzed aerobic oxidation of aldehydes in water was developed. This method utilizes 1 atmosphere of oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification. Its operational simplicity, gram‐scale oxidation, and the ability to successively reuse the catalyst, make this new methodology environmentally benign and cost effective. The generality of this methodology gives it the potential to be used on an industrial scale.

Abstract The reversible regulation of catalytic activity is a feature found in natural enzymes which is not commonly observed in artificial catalytic systems. Here, we fabricate an artificial hydrolase with pH‐switchable activity, achieved by introducing a catalytic histidine residue at the terminus of a pH‐responsive peptide. The peptide exhibits a conformational transition from random coil to β‐sheet by changing the pH from acidic to alkaline. The β‐sheet self‐assembles to form long fibrils with the hydrophobic edge and histidine residues extending in an ordered array as the catalytic microenvironment, which shows significant esterase activity. Catalytic activity can be reversible switched by pH‐induced assembly/disassembly of the fibrils into random coils. At higher concentrations, the peptide forms a hydrogel which is also catalytically active and maintains its reversible (de‐)activation.

Abstract Conversion of carbon dioxide (CO 2 ) into fuels and chemicals by electroreduction has attracted significant interest, although it suffers from a large overpotential and low selectivity. A Pd‐Sn alloy electrocatalyst was developed for the exclusive conversion of CO 2 into formic acid in an aqueous solution. This catalyst showed a nearly perfect faradaic efficiency toward formic acid formation at the very low overpotential of −0.26 V, where both CO formation and hydrogen evolution were completely suppressed. Density functional theory (DFT) calculations suggested that the formation of the key reaction intermediate HCOO* as well as the product formic acid was the most favorable over the Pd‐Sn alloy catalyst surface with an atomic composition of PdSnO 2 , consistent with experiments.

Abstract Photothermal therapy (PTT) has shown significant potential for cancer therapy. However, developing nanomaterials (NMs)‐based photothermal agents (PTAs) with satisfactory photothermal conversion efficacy (PTCE) and biocompatibility remains a key challenge. Herein, a new generation of PTAs based on two‐dimensional (2D) antimonene quantum dots (AMQDs) was developed by a novel liquid exfoliation method. Surface modification of AMQDs with polyethylene glycol (PEG) significantly enhanced both biocompatibility and stability in physiological medium. The PEG‐coated AMQDs showed a PTCE of 45.5 %, which is higher than many other NMs‐based PTAs such as graphene, Au, MoS2, and black phosphorus (BP). The AMQDs‐based PTAs also exhibited a unique feature of NIR‐induced rapid degradability. Through both in vitro and in vivo studies, the PEG‐coated AMQDs demonstrated notable NIR‐induced tumor ablation ability. This work is expected to expand the utility of 2D antimonene (AM) to biomedical applications through the development of an entirely novel PTA platform.

Abstract Seit einigen Jahren erleben wir einen deutlichen Anstieg bei der Erzeugung nachhaltiger und erneuerbarer Energien. Allerdings sind die elektrochemischen Ausbeuten der verschiedenen Energiegewinnungssysteme limitiert, und es findet daher eine intensive Suche nach hocheffizienten Elektrokatalysatoren durch rationale Kontrolle von Größe, Form, Zusammensetzung und Struktur statt. Von besonderem Interesse für die Elektrokatalyse sind Einzelatomkatalysatoren (single‐atom catalysts, SACs), die sich durch hohe katalytische Aktivitäten, Stabilität, Selektivität und 100 % Atomausnutzung auszeichnen. In diesem Aufsatz stellen wir innovative Synthesen und Charakterisierungstechniken für SACs vor, mit einem Fokus auf elektrochemischen Anwendungen in der Sauerstoffreduktion und Sauerstoffentwicklung, der Wasserstoffentwicklung und der Kohlenwasserstoffkonversion in Brennstoffzellen (Elektrooxidation von Methanol, Ethanol und Ameisensäure). Wir betrachten ferner elektrokatalytische Vorgänge auf atomarer Ebene und erörtern die zugrundeliegenden Mechanismen. Das ultimative Ziel dieser…

Abstract The highly efficient electrochemical hydrogen evolution reaction (HER) provides a promising pathway to resolve energy and environment problems. An electrocatalyst was designed with single Mo atoms (Mo‐SAs) supported on N‐doped carbon having outstanding HER performance. The structure of the catalyst was probed by aberration‐corrected scanning transmission electron microscopy (AC‐STEM) and X‐ray absorption fine structure (XAFS) spectroscopy, indicating the formation of Mo‐SAs anchored with one nitrogen atom and two carbon atoms (Mo1N1C2). Importantly, the Mo1N1C2 catalyst displayed much more excellent activity compared with Mo2C and MoN, and better stability than commercial Pt/C. Density functional theory (DFT) calculation revealed that the unique structure of Mo1N1C2 moiety played a crucial effect to improve the HER performance. This work opens up new opportunities for the preparation and application of highly active and stable Mo‐based HER catalysts.

Abstract Owing to the transient nature of the intermediates formed during the oxygen evolution reaction (OER) on the surface of transition metal oxides, their nature remains largely elusive by the means of simple techniques. The use of chemical probes is proposed, which, owing to their specific affinities towards different oxygen species, unravel the role played by these species on the OER mechanism. For that, tetraalkylammonium (TAA) cations, previously known for their surfactant properties, are introduced, which interact with the active oxygen sites and modify the hydrogen bond network on the surface of OER catalysts. Combining chemical probes with isotopic and pH‐dependent measurements, it is further demonstrated that the introduction of iron into amorphous Ni oxyhydroxide films used as model catalysts deeply modifies the proton exchange properties, and therefore the OER mechanism and activity.

Abstract Die Regulation biologischer Vorgänge in der Natur unterliegt einer strengen räumlichen und zeitlichen Steuerung; eines der offensichtlichsten Beispiele ist die Embryogenese bei Metazoen. Zahlreiche chemische Werkzeuge wurden in der Zell‐ und Entwicklungsbiologie zur Untersuchung zellulärer Prozesse genutzt. Durch regelbare Steuerungsmethoden wurden die Anwendungsmöglichkeiten dieser Verfahren auch auf komplexe biologische Fragestellungen ausgeweitet. Licht eignet sich ausgezeichnet als externer Impuls, denn es kann mit sehr hoher räumlicher und zeitlicher Genauigkeit eingesetzt werden. Dazu wurden verschiedene optisch regulierte Werkzeuge entwickelt und auf lebende Systeme angewendet. In diesem Aufsatz diskutieren wir die aktuellen Entwicklungen optochemischer Werkzeuge, darunter niedermolekulare Verbindungen, Peptide, Proteine und Nukleinsäuren, die durch Lichteinstrahlung irreversibel oder reversibel kontrolliert werden können, insbesondere für Anwendungen in Zellen und in Tieren.

Abstract A conceptually novel strategy with achiral pyridine as the ancillary ligand to stabilize high‐valent copper species for the first asymmetric radical oxytrifluoromethylation of alkenes with alcohols under CuI/phosphoric acid dual‐catalysis has been developed. The transformation features mild reaction conditions, a remarkably broad substrate scope and excellent functional group tolerance, offering an efficient approach to a wide range of trifluoromethyl‐substituted tetrahydrofurans bearing an α‐tertiary stereocenter with excellent enantioselectivity. Mechanistic studies support the presumed role of the achiral pyridine as a coordinative ligand on copper metal to stabilize the key transient reaction species involved in the asymmetric induction process.

Abstract Die metallkatalysierte Kreuzkupplung ist eine der wichtigsten Umwandlungen der organischen Synthese. Aufgrund der geringen Toxizität und des günstigen Preises von Kupfer hat die Kupferkatalyse viel Interesse geweckt. Die traditionelle Ullmann‐Kupplung hat jedoch eine geringe Substratbreite und erfordert harsche Reaktionsbedingungen. In den vergangenen zwei Jahrzehnten wurden zweizähnige Liganden, z. B. Aminosäuren, Diamine, 1,3‐Diketone und Oxalsäurediamide, eingeführt, die Cu‐katalysierte Kupplungen von Arylhalogeniden und Nucleophilen sowohl bei niedrigen Temperaturen als auch in katalytischer Weise ermöglichen. Dadurch ist die Cu‐vermittelte Kreuzkupplung zu einer attraktiven Reaktion für die akademische Forschung und die Industrie geworden. Dieser Aufsatz fasst Fortschritte bei Kupplungen von (Hetero)Arylhalogeniden mit verschiedenen Nucleophilen zusammen und stellt Entwicklungen bei Cu‐katalysierten Kupplungen mit Arylboronaten und Cu‐vermittelten Trifluormethylierungen von aromatischen Elektrophilen vor.

Abstract Manganese(I)‐catalyzed C−H alkynylations with organic halides occurred with unparalleled substrate scope, and thus enabled step‐economical C−H functionalizations with silyl, aryl, alkenyl, and alkyl haloalkynes. The versatility of the manganese(I) catalysis manifold enabled C−H couplings with haloalkynes featuring, among others, fluorescent labels, steroids, and amino acids, thereby setting the stage for peptide ligation as well as the efficient molecular assembly of acyclic and cyclic peptides. A plausible catalytic cycle was proposed.

Abstract An einen Übersichtsartikel aus dem Jahre 2004 anknüpfend, wird hier über den strukturellen Aufbau, die Stabilität und die Anwendungen moderner schwach koordinierender Anionen (weakly coordinating anions, WCAs) berichtet, aber auch über Fortschritte der “klassischen” WCAs. In tabellarischer Form werden sowohl Ausgangsverbindungen zur Einführung einer Vielzahl von WCAs als auch deren physikochemische Eigenschaften zusammengefasst. Damit lässt sich für mögliche Anwendungen gut beurteilen, wie WCAs am besten in vorgegebene Systeme inkorporiert werden können. Die angeführten Anwendungsbeispiele für WCAs sind breit gestreut, eigene Abschnitte bilden aber die Schwerpunkte Übergangsmetallkomplexe, katalytische Anwendungen und Leitsalze für elektrochemische Anwendungen.

Abstract The lithium–sulfur (Li–S) battery is a promising high‐energy‐density storage system. The strong anchoring of intermediates is widely accepted to retard the shuttle of polysulfides in a working battery. However, the understanding of the intrinsic chemistry is still deficient. Inspired by the concept of hydrogen bond, herein we focus on the Li bond chemistry in Li–S batteries through sophisticated quantum chemical calculations, in combination with 7Li nuclear magnetic resonance (NMR) spectroscopy. Identified as Li bond, the strong dipole–dipole interaction between Li polysulfides and Li–S cathode materials originates from the electron‐rich donors (e.g., pyridinic nitrogen (pN)), and is enhanced by the inductive and conjugative effect of scaffold materials with π‐electrons (e.g., graphene). The chemical shift of Li polysulfides in 7Li NMR spectroscopy, being both theoretically predicted and experimentally verified, is suggested to serve as a quantitative descriptor of Li bond strength. These theoretical insights were further proved by actual electrochemical tests. This work…

Abstract Poröse organische Materialien sind eine aufstrebende Klasse funktionaler Nanostrukturen mit beispiellosen Eigenschaften. Die dynamisch‐kovalente Organisation kleiner organischer Bausteine unter thermodynamischer Kontrolle wird dabei für die verblüffend einfache Bildung komplexer Architekturen in Eintopfreaktionen genutzt. In diesem Aufsatz werden die grundlegenden Designprinzipien analysiert, die zur Bildung von entweder kovalenten organischen Netzwerken als kristalline poröse Polymere oder kovalenten organischen Käfigverbindungen als formgetreue molekulare Objekte führen. Konventionelle Synthesevorschriften und Analysemethoden werden neben ausgefeilteren Strategien, wie postsynthetische Modifizierungen oder Selbstsortierung, diskutiert. Gegebenenfalls werden die entsprechenden Eigenschaften und Besonderheiten von polymeren Netzwerken und diskreten organischen Käfigen verglichen. Darüber hinaus wird das Potenzial dieser Materialien für Anwendungen, von der Gasspeicherung über die Katalyse bis hin zur organischen Elektronik, erörtert.

Abstract Despite high morbidity and mortality associated with lung diseases, addressing drugs towards lung tissue remains a pending task. Particle lung filtration has been proposed for passive lung targeting and drug delivery. However, toxicity issues derived from the long‐term presence of the particles must be overcome. By exploiting some of the ignored properties of nanosized metal–organic frameworks it is possible to achieve impressive antitumoral effects on experimental lung tumors, even without the need to engineer the surface of the material. In fact, it was discovered that, based on unique pH‐responsiveness and reversible aggregation behaviors, nanoMOF was capable of targeting lung tissue. At the neutral pH of the blood, the nanoMOFs form aggregates with the adequate size to be retained in lung capillaries. Within 24 h they then disaggregate and release their drug payload. This phenomenon was compatible with lung tissue physiology.

Abstract Lead‐based perovskite nanocrystals (NCs) have outstanding optical properties and cheap synthesis conferring them a tremendous potential in the field of optoelectronic devices. However, two critical problems are still unresolved and hindering their commercial applications: one is the fact of being lead‐based and the other is the poor stability. Lead‐free all‐inorganic perovskite Cs3Bi2X9 (X=Cl, Br, I) NCs are synthesized with emission wavelength ranging from 400 to 560 nm synthesized by a facile room temperature reaction. The ligand‐free Cs3Bi2Br9 NCs exhibit blue emission with photoluminescence quantum efficiency (PLQE) about 0.2 %. The PLQE can be increased to 4.5 % when extra surfactant (oleic acid) is added during the synthesis processes. This improvement stems from passivation of the fast trapping process (2–20 ps). Notably, the trap states can also be passivated under humid conditions, and the NCs exhibited high stability towards air exposure exceeding 30 days.

Abstract The adsorption of molecules on metal nanoparticles can be sterically controlled through the use of zeolite crystals, which enhances the product selectivity in hydrogenations of reactants with more than one reducible group. Key to this success was the fixation of Pd nanoparticles inside Beta zeolite crystals to form a defined structure (Pd@Beta). In the hydrogenation of substituted nitroarenes with multiple reducible groups as a model reaction, the Pd@Beta catalyst exhibited superior selectivity for hydrogenation of the nitro group, outperforming both conventional Pd nanoparticles supported on zeolite crystals and a commercial Pd/C catalyst. The extraordinary selectivity of Pd@Beta was attributed to the sterically selective adsorption of the nitroarenes on the Pd nanoparticles controlled by the zeolite micropores, as elucidated by competitive adsorption and adsorbate displacement tests. Importantly, this strategy is general and was extended to the synthesis of selective Pt and Ru catalysts by fixation inside Beta and mordenite zeolites.

Abstract Layered materials are of high importance because of their anisotropy and as a source of 2D materials. Whilst there is a plethora of multi‐elemental 2D materials, the number mono‐elemental 2D materials is rather limited. Herein, we demonstrate that aqueous shear exfoliation can be used to obtain As, Sb, and Bi exfoliated nanosheets. Morphological and chemical characterization of the exfoliated materials shows a decrease in thickness, sheet‐to‐nanosheet scale, and partial oxidation owing to a higher surface area. The electrochemical performance is tested in terms of inherent electrochemistry, electron transfer, and sensing applications as demonstrated with ascorbic acid. Potential energy‐related applications are evaluated in the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR), with shear‐exfoliated Sb having the best electrochemical performance overall. These findings will have a profound impact on the preparation and application of 2D mono‐elemental materials.

Abstract The delamination of layered crystals that produces single or few‐layered nanosheets while enabling exotic physical and chemical properties, particularly for semiconductor functions in optoelectronic applications, remains a challenge. Here, we report a facile and green approach to prepare few‐layered polymeric carbon nitride (PCN) semiconductors by a one‐step carbon/nitrogen steam reforming reaction. Bulky PCN, obtained from typical precursors including urea, melamine, dicyandiamide, and thiourea, are exfoliated into few‐layered nanosheets, while engineering its surface carbon vacancies. The unique sheet structures with strengthened surface properties endow PCNs with more active sites, and an increased charge separation efficiency with a prolonged charge lifetime, drastically promoting their photoredox performance. After an assay of a H2 evolution reaction, an apparent quantum yield of 11.3 % at 405 nm was recorded for the PCN nanosheets, which is much higher than those of PCN nanosheets. This delamination method is expandable to other carbon‐based 2D materials for advanced…

Abstract Deep‐ultraviolet nonlinear optical (DUV NLO) crystals are the key materials to extend the output range of solid‐state lasers to below 200 nm. The only practical material KBe2BO3F2 suffers high toxicity through beryllium and strong layered growth. Herein, we propose a beryllium‐free material design and synthesis strategy for DUV NLO materials. Introducing the (BO3F)4−, (BO2F2)3−, and (BOF3)2− groups in borates could break through the fixed 3D B–O network that would produce a larger birefringence without layering and simultaneously keep a short cutoff edge down to DUV. The theoretical and experimental studies on a series of fluorooxoborates confirm this strategy. Li2B6O9F2 is identified as a DUV NLO material with a large second harmonic generation efficiency (0.9×KDP) and a large predicted birefringence (0.07) without layering. This study provides a feasible way to break down the DUV wall for NLO materials.

Abstract Various advanced catalysts based on sulfur‐doped Fe/N/C materials have recently been designed for the oxygen reduction reaction (ORR); however, the enhanced activity is still controversial and usually attributed to differences in the surface area, improved conductivity, or uncertain synergistic effects. Herein, a sulfur‐doped Fe/N/C catalyst (denoted as Fe/SNC) was obtained by a template‐sacrificing method. The incorporated sulfur gives a thiophene‐like structure (C−S−C), reduces the electron localization around the Fe centers, improves the interaction with oxygenated species, and therefore facilitates the complete 4 e − ORR in acidic solution. Owing to these synergistic effects, the Fe/SNC catalyst exhibits much better ORR activity than the sulfur‐free variant (Fe/NC) in 0.5 m H 2 SO 4 .

Abstract Selectivity control in hydroarylation‐based C−H alkylation has been dominated by steric interactions. A conceptually distinct strategy that exploits the programmed switch in the C−H activation mechanism by means of cobalt catalysis is presented, which sets the stage for convenient C−H alkylations with unactivated alkenes. Detailed mechanistic studies provide compelling evidence for a programmable switch in the C−H activation mechanism from a linear‐selective ligand‐to‐ligand hydrogen transfer to a branched‐selective base‐assisted internal electrophilic‐type substitution.

Abstract To use water as the source of electrons for proton or CO2 reduction within electrocatalytic devices, catalysts are required for facilitating the proton‐coupled multi‐electron oxygen evolution reaction (OER, 2 H2O→O2+4 H++4 e−). These catalysts, ideally based on cheap and earth abundant metals, have to display high activity at low overpotential and good stability and selectivity. While numerous examples of Co, Mn, and Ni catalysts were recently reported for water oxidation, only few examples were reported using copper, despite promising efficiencies. A rationally designed nanostructured copper/copper oxide electrocatalyst for OER is presented. This material derives from conductive copper foam passivated by a copper oxide layer and further nanostructured by electrodeposition of CuO nanoparticles. The generated electrodes are highly efficient for catalyzing selective water oxidation to dioxygen with an overpotential of 290 mV at 10 mA cm−2 in 1 m NaOH solution.

Abstract Nicht‐ribosomale Peptidsynthetasen (NRPSs) sind große Multienzymmaschinerien, die zahlreiche Peptide mit enormer struktureller und funktionaler Diversität erzeugen. Unter diesen Produkten befinden sich mehr als 20 auf dem Markt befindliche Wirkstoffe, darunter Antibiotika (Penicillin, Vancomycin), antitumorale Medikamente (Bleomycin) und Immunsuppressiva (Cyclosporin). In den vergangenen Jahrzehnten haben biochemische sowie strukturbiologische Studien mechanistische Einblicke in die hochkomplexen NRPSs gewährt. Dieser Aufsatz fasst den aktuellen Kenntnisstand über die zugrundeliegenden Mechanismen von NRPSs zusammen und gibt einen Überblick über die Vielfalt ihrer Produkte. Ebenso behandelt werden die Probleme und Herausforderungen, die mit der Umprogrammierung von NRPS‐Systemen einhergehen. Das Potenzial einer solchen Umprogrammierung liegt begründet in einer nachhaltigen Generierung von Wirkstoffanaloga und neuen Substanzbibliotheken, die anderenfalls kaum zugänglich sind.

Abstract Proton adsorption on metallic catalysts is a prerequisite for efficient hydrogen evolution reaction (HER). However, tuning proton adsorption without perturbing metallicity remains a challenge. A Schottky catalyst based on metal–semiconductor junction principles is presented. With metallic MoB, the introduction of n‐type semiconductive g‐C 3 N 4 induces a vigorous charge transfer across the MoB/g‐C 3 N 4 Schottky junction, and increases the local electron density in MoB surface, confirmed by multiple spectroscopic techniques. This Schottky catalyst exhibits a superior HER activity with a low Tafel slope of 46 mV dec −1 and a high exchange current density of 17 μA cm −2 , which is far better than that of pristine MoB. First‐principle calculations reveal that the Schottky contact dramatically lowers the kinetic barriers of both proton adsorption and reduction coordinates, therefore benefiting surface hydrogen generation.

Abstract Fabrication of hybrid MOF‐on‐MOF heteroarchitectures can create novel and multifunctional platforms to achieve desired properties. However, only MOFs with similar crystallographic parameters can be hybridized by the classical epitaxial growth method (EGM), which largely suppressed its applications. A general strategy, called internal extended growth method (IEGM), is demonstrated for the feasible assembly of MOFs with distinct crystallographic parameters in an MOF matrix. Various MOFs with diverse functions could be introduced in a modular MOF matrix to form 3D core–satellite pluralistic hybrid system. The number of different MOF crystals interspersed could be varied on demand. More importantly, the different MOF crystals distributed in individual domains could be used to further incorporate functional units or enhance target functions.

Abstract Two typical types of luminescent organic cocrystals comprising pyrene–octafluoronaphthalene (pyrene–OFN) and pyrene–1,2,4,5‐tetracyanobezene (pyrene–TCNB) were developed by a simple supramolecular assembly strategy. The cocrystals exhibit distinct optical properties because of their different intermolecular interaction modes; that is, arene–perfluoroarene (AP) and charge‐transfer (CT) interactions. Unexpectedly, a pyrene–TCNB system with strong CT interactions was incorporated into a pyrene–OFN host as a robust guest to generate white‐light emission (WLE). In the supramolecular cocrystal system, an efficient energy‐transfer process from pyrene–OFN to pyrene–TCNB occurred because of the well‐matched spectra of the constituents and a desirable energy donor/acceptor (D/A) distance. The present competitive intermolecular interaction strategy could be applied to the fabrication of more complicated organic light‐harvesting systems.

Abstract Herein we introduce a straightforward, low cost, scalable, and technologically relevant method to manufacture an all‐carbon, electroactive, nitrogen‐doped nanoporous‐carbon/carbon‐nanotube composite membrane, dubbed “HNCM/CNT”. The membrane is demonstrated to function as a binder‐free, high‐performance gas diffusion electrode for the electrocatalytic reduction of CO2 to formate. The Faradaic efficiency (FE) for the production of formate is 81 %. Furthermore, the robust structural and electrochemical properties of the membrane endow it with excellent long‐term stability.

Abstract Atroposelective synthesis of axially chiral biaryls by palladium‐catalyzed C−H olefination, using tert‐leucine as an inexpensive, catalytic, and transient chiral auxiliary, has been realized. This strategy provides a highly efficient and straightforward access to a broad range of enantioenriched biaryls in good yields (up to 98 %) with excellent enantioselectivities (95 to >99 % ee). Kinetic resolution of trisubstituted biaryls bearing sterically more demanding substituents is also operative, thus furnishing the optically active olefinated products with excellent selectivity (95 to >99 % ee, s‐factor up to 600).

Abstract Conjugated polymers (CPs) are emerging and appealing light harvesters for photocatalytic water splitting owing to their adjustable band gap and facile processing. Herein, we report an advanced mild synthesis of three conjugated triazine‐based polymers (CTPs) with different chain lengths by increasing the quantity of electron‐donating benzyl units in the backbone. Varying the chain length of the CTPs modulates their electronic, optical, and redox properties, resulting in an enhanced performance for photocatalytic oxygen evolution, which is the more challenging half‐reaction of water splitting owing to the sluggish reaction kinetics. Our results could stimulate interest in these functional polymers where a molecular engineering strategy enables the production of suitable semiconductor redox energetics for oxygenic photosynthesis.

Abstract Recently, Cu I ‐ and Ag I ‐based halide double perovskites have been proposed as promising candidates for overcoming the toxicity and instability issues inherent within the emerging Pb‐based halide perovskite absorbers. However, up to date, only Ag I ‐based halide double perovskites have been experimentally synthesized; there are no reports on successful synthesis of Cu I ‐based analogues. Here we show that, owing to the much higher energy level for the Cu 3d 10 orbitals than for the Ag 4d 10 orbitals, Cu I atoms energetically favor 4‐fold coordination, forming [CuX 4 ] tetrahedra (X=halogen), but not 6‐fold coordination as required for [CuX 6 ] octahedra. In contrast, Ag I atoms can have both 6‐ and 4‐fold coordinations. Our density functional theory calculations reveal that the synthesis of Cu I halide double perovskites may instead lead to non‐perovskites containing [CuX 4 ] tetrahedra, as confirmed by our material synthesis efforts.

Abstract Covalent triazine frameworks (CTFs) are normally synthesized by ionothermal methods. The harsh synthetic conditions and associated limited structural diversity do not benefit for further development and practical large‐scale synthesis of CTFs. Herein we report a new strategy to construct CTFs (CTF‐HUSTs) via a polycondensation approach, which allows the synthesis of CTFs under mild conditions from a wide array of building blocks. Interestingly, these CTFs display a layered structure. The CTFs synthesized were also readily scaled up to gram quantities. The CTFs are potential candidates for separations, photocatalysis and for energy storage applications. In particular, CTF‐HUSTs are found to be promising photocatalysts for sacrificial photocatalytic hydrogen evolution with a maximum rate of 2647 μmol h−1 g−1 under visible light. We also applied a pyrolyzed form of CTF‐HUST‐4 as an anode material in a sodium‐ion battery achieving an excellent discharge capacity of 467 mAh g−1.

Abstract Highly enantioselective iron‐catalyzed C−H alkylations by inner‐sphere C−H activation were accomplished with ample scope. High levels of enantiocontrol proved viable through a novel ligand design that exploits a remote meta‐substitution on N‐heterocyclic carbenes within a facile ligand‐to‐ligand H‐transfer C−H cleavage.

Abstract A photoinduced cascade strategy leading to a variety of differentially functionalised nitriles and ketones has been developed. These reactions rely on the oxidative generation of iminyl radicals from simple oximes. Radical transposition by C(sp 3 )−(sp 3 ) and C(sp 3 )−H bond cleavage gives access to distal carbon radicals that undergo S H 2 functionalisations. These mild, visible‐light‐mediated procedures can be used for remote fluorination, chlorination, and azidation, and were applied to the modification of bioactive and structurally complex molecules.

Abstract CO2 capture is a pressing global environmental issue that drives scientists to develop creative strategies for tackling this challenge. The concept in this contribution is to produce site‐specific nitrogen doping in microporous carbon fibers. Following this approach a carbon/carbon heterojunction is created by using a poly(ionic liquid) (PIL) as a “soft” activation agent that deposits nitrogen species exclusively on the surface of commercial microporous carbon fibers. This type of carbon‐based biphasic heterojunction amplifies the interaction between carbon fiber and CO2 molecule for unusually high CO2 uptake and resistive sensing.

Abstract Sulfuryl fluoride, SO2F2, has been found to derivatize phenols in all kinds of environments, even those in highly functional molecules. We now report that a solid fluorosulfuryl imidazolium triflate salt delivers the same “F−SO2+” fragment to Nu−H acceptor groups in the substrates. However, this triflate salt is a far more reactive fluorosulfurylating agent than SO2F2 and displays selectivity preferences of its own. Moreover, the new azolium triflate reagent reacts once with primary amines and anilines before the reaction stops. On the other hand, with triethylamine and two equivalents of the “F−SO2+” donor present, it proceeds on to the bis(fluorosulfuryl)imides in good yield—two important conversions that we have never seen with sulfuryl fluoride as the electrophile.

Abstract The oxygen evolution reaction (OER) is involved in various renewable energy systems, such as water‐splitting cells and metal–air batteries. Ni‐Fe layered double hydroxides (LDHs) have been reported as promising OER electrocatalysts in alkaline electrolytes. The rational design of advanced nanostructures for Ni‐Fe LDHs is highly desirable to optimize their electrocatalytic performance. Herein, we report a facile self‐templated strategy for the synthesis of novel hierarchical hollow nanoprisms composed of ultrathin Ni‐Fe LDH nanosheets. Tetragonal nanoprisms of nickel precursors were first synthesized as the self‐sacrificing template. Afterwards, these Ni precursors were consumed during the hydrolysis of iron(II) sulfate for the simultaneous growth of a layer of Ni‐Fe LDH nanosheets on the surface. The resultant Ni‐Fe LDH hollow prisms with large surface areas manifest high electrocatalytic activity towards the OER with low overpotential, small Tafel slope, and remarkable stability.

Abstract We report a facile approach to prepare an artificial enzyme system for tandem catalysis. NiPd hollow nanoparticles and glucose oxidase (GOx) were simultaneously immobilized on the zeolitic imidazolate framework 8 (ZIF‐8) via a co‐precipitation method. The as‐prepared GOx@ZIF‐8(NiPd) nanoflower not only exhibited the peroxidase‐like activity of NiPd hollow nanoparticles but also maintained the enzymatic activity of GOx. A colorimetric sensor for rapid detection of glucose was realized through the GOx@ZIF‐8(NiPd) based multi‐enzyme system. Moreover, the GOx@ZIF‐8(NiPd) modified electrode showed good bioactivity of GOx and high electrocatalytic activity for the oxygen reduction reaction (ORR), which could also be used for electrochemical detection of glucose.

Abstract Complex metal–organic frameworks used as precursors allow design and construction of various nanostructured functional materials which might not be accessible by other methods. Here, we develop a sequential chemical etching and sulfurization strategy to prepare well‐defined double‐shelled zinc–cobalt sulfide (Zn‐Co‐S) rhombic dodecahedral cages (RDCs). Yolk‐shelled zinc/cobalt‐based zeolitic imidazolate framework (Zn/Co‐ZIF) RDCs are first synthesized by a controlled chemical etching process, followed by a hydrothermal sulfurization reaction to prepare double‐shelled Zn‐Co‐S RDCs. Moreover, the strategy reported in this work enables easy control of the Zn/Co molar ratio in the obtained double‐shelled Zn‐Co‐S RDCs. Owing to the structural and compositional benefits, the obtained double‐shelled Zn‐Co‐S RDCs exhibit enhanced performance with high specific capacitance (1266 F g−1 at 1 A g−1), good rate capability and long‐term cycling stability (91 % retention over 10,000 cycles) as a battery‐type electrode material for hybrid supercapacitors.

Abstract Highly active, stable, and cheap Pt‐free catalysts for the hydrogen evolution reaction (HER) are under increasing demand for future energy conversion systems. However, developing HER electrocatalysts with Pt‐like activity that can function at all pH values still remains as a great challenge. Herein, based on our theoretical predictions, we design and synthesize a novel N,P dual‐doped carbon‐encapsulated ruthenium diphosphide (RuP2@NPC) nanoparticle electrocatalyst for HER. Electrochemical tests reveal that, compared with the Pt/C catalyst, RuP2@NPC not only has Pt‐like HER activity with small overpotentials at 10 mA cm−2 (38 mV in 0.5 m H2SO4, 57 mV in 1.0 m PBS and 52 mV in 1.0 m KOH), but demonstrates superior stability at all pH values, as well as 100 % Faradaic yields. Therefore, this work adds to the growing family of transition‐metal phosphides/heteroatom‐doped carbon heterostructures with advanced performance in HER.

Abstract Nitrogen‐enriched porous nanocarbon, graphene, and conductive polymers attract increasing attention for application in supercapacitors. However, electrode materials with a large specific surface area (SSA) and a high nitrogen doping concentration, which is needed for excellent supercapacitors, has not been achieved thus far. Herein, we developed a class of tetracyanoquinodimethane‐derived conductive microporous covalent triazine‐based frameworks (TCNQ‐CTFs) with both high nitrogen content (>8 %) and large SSA (>3600 m 2 g −1 ). These CTFs exhibited excellent specific capacitances with the highest value exceeding 380 F g −1 , considerable energy density of 42.8 Wh kg −1 , and remarkable cycling stability without any capacitance degradation after 10 000 cycles. This class of CTFs should hold a great potential as high‐performance electrode material for electrochemical energy‐storage systems.

Abstract The particle size effect of Pd nanoparticles supported on alumina with various crystalline phases on methane combustion was investigated. Pd/θ, α‐Al2O3 with weak metal‐support interaction showed a volcano‐shaped dependence of the catalytic activity on the size of Pd particles, and the catalytic activity of the strongly interacted Pd/γ‐Al2O3 increased with the particle size. Based on a structural analysis of Pd nanoparticles using CO adsorption IR spectroscopy and spherical aberration‐corrected scanning/transmission electron microscopy, the dependence of catalytic activity on Pd particle size and the alumina crystalline phase was due to the fraction of step sites on Pd particle surface. The difference in fraction of the step site is derived from the particle shape, which varies not only with Pd particle size but also with the strength of metal–support interaction. Therefore, this interaction perturbs the particle size effect of Pd/Al2O3 for methane combustion.

Abstract Two stable, purely organic luminogens exhibit both mechano‐ (ML) and photoluminescence (PL) with dual fluorescence–phosphorescence emissions at room temperature. Careful analysis of the crystal structures, coupled with theoretical calculations, demonstrate that room‐temperature phosphorescence and ML properties are strongly related to molecular packing. In particular, the formation and fracture of molecular dimers with intermolecular charge‐transfer properties has a significant effect on intersystem crossing, as well as excited triplet state emissions, in both PL and ML processes.

Abstract Eine Deaminierungsstrategie für die durch sichtbares Licht vermittelte Erzeugung von Alkylradikalen aus redoxaktivierten primären Amin‐Vorstufen wird beschrieben. Häufig vorkommende und preiswerte primäre Amine, einschließlich der Aminosäuren, wurden in einem Schritt in redoxaktive Pyridiniumsalze und anschließend in Alkylradikale durch Umsetzung mit einem angeregten Photokatalysator umgesetzt. Das Potenzial dieses Protokolls für Synthesen wurde durch die einfach durchzuführende Alkylierung einer Anzahl von Heteroarenen unter milden Bedingungen nachgewiesen.

Abstract The step‐change in gravimetric energy density needed for electrochemical energy storage devices to power unmanned autonomous vehicles, electric vehicles, and enable low‐cost clean grid storage is unlikely to be provided by conventional lithium ion batteries. Lithium–sulfur batteries comprising lightweight elements provide a promising alternative, but the associated polysulfide shuttle in typical ether‐based electrolytes generates loss in capacity and low coulombic efficiency. The first new electrolyte based on a unique combination of a relatively hydrophobic sulfonamide solvent and a low ion‐pairing salt, which inhibits the polysulfide shuttle, is presented. This system behaves as a sparingly solvating electrolyte at slightly elevated temperatures, where it sustains reversible capacities as high as 1200–1500 mAh g−1 over a wide range of current density (2C–C/5, respectively) when paired with a lithium metal anode, with a coulombic efficiency of >99.7 % in the absence of LiNO3 additive.

Abstract Along with amide bond formation, Suzuki cross‐coupling, and reductive amination, the Buchwald–Hartwig–Ullmann‐type amination of aryl halides stands as one of the most employed reactions in modern medicinal chemistry. The work herein demonstrates the potential of utilizing electrochemistry to provide a complementary avenue to access such critical bonds using an inexpensive nickel catalyst under mild reaction conditions. Of note is the scalability, functional‐group tolerance, rapid rate, and the ability to employ a variety of aryl donors (Ar−Cl, Ar−Br, Ar−I, Ar−OTf), amine types (primary and secondary), and even alternative X−H donors (alcohols and amides).

Abstract A series of novel imide‐functionalized ladder‐type heteroarenes with well‐defined structure and controllable conjugation lengths were synthesized and characterized. The synthetic route shows remarkable efficacy for constructing the electron‐deficient ladder backbones. π‐Conjugation extension leads to narrowed band gaps with enhanced electron affinities. The ladder arenes are incorporated into organic thin‐film transistors, and show encouraging electron mobilities of 0.013–0.045 cm2 V−1 s−1. The heteroarenes reported here provide a remarkable platform for fundamental physicochemical studies and materials innovation in organic electronics.

Abstract The metallic 1T‐MoS2 has attracted considerable attention as an effective catalyst for hydrogen evolution reactions (HERs). However, the fundamental mechanism about the catalytic activity of 1T‐MoS2 and the associated phase evolution remain elusive and controversial. Herein, we prepared the most stable 1T‐MoS2 by hydrothermal exfoliation of MoS2 nanosheets vertically rooted into rigid one‐dimensional TiO2 nanofibers. The 1T‐MoS2 can keep highly stable over one year, presenting an ideal model system for investigating the HER catalytic activities as a function of the phase evolution. Both experimental studies and theoretical calculations suggest that 1T phase can be irreversibly transformed into a more active 1T′ phase as true active sites in photocatalytic HERs, resulting in a “catalytic site self‐optimization”. Hydrogen atom adsorption is the major driving force for this phase transition.

Abstract Two‐dimensional (2D) layered hybrid perovskites have shown great potential in optoelectronics, owing to their unique physical attributes. However, 2D hybrid perovskite ferroelectrics remain rare. The first hybrid ferroelectric with unusual 2D multilayered perovskite framework, (C 4 H 9 NH 3 ) 2 (CH 3 NH 3 ) 2 Pb 3 Br 10 ( 1 ), has been constructed by tailored alloying of the mixed organic cations into 3D prototype of CH 3 NH 3 PbBr 3 . Ferroelectricity is created through molecular reorientation and synergic ordering of organic moieties, which are unprecedented for the known 2D multilayered hybrid perovskites. Single‐crystal photodetectors of 1 exhibit fascinating performances, including extremely low dark currents (ca. 10 −12 A), large on/off current ratios (ca. 2.5×10 3 ), and very fast response rate (ca. 150 μs). These merits are superior to integrated detectors of other 2D perovskites, and compete with the most active CH 3 NH 3 PbI 3 .

Abstract C3‐substituted indoles and carbazoles react with α‐aryl‐α‐diazoesters under palladium catalysis to form α‐(N‐indolyl)‐α‐arylesters and α‐(N‐carbazolyl)‐α‐arylesters. The products result from insertion of a palladium‐carbene ligand into the N−H bond of the aromatic N‐heterocycles. Enantioselection was achieved using a chiral bis(oxazoline) ligand, in many cases with high enantioselectivity (up to 99 % ee). The method was applied to synthesize the core of a bioactive carbazole derivative in a concise manner.

Abstract Die Wasserstoffentwicklungsreaktion (hydrogen evolution reaction, HER) ist ein grundlegender Vorgang in der Elektrokatalyse und spielt eine wichtige Rolle bei der Energieumwandlung zur Entwicklung von wasserstoffbasierten Energiequellen. Die recht langsame Geschwindigkeit der HER unter alkalischen Bedingungen hemmte jedoch die Fortschritte bei Wasserspaltungsverfahren zur Produktion von hochreinem Wasserstoff. Anders als bei der gut dokumentierten sauren HER sind die mechanistischen Aspekte der alkalischen HER noch zu klären. Wir legen eine kritische Bewertung der alkalischen HER‐Elektrokatalyse vor, unter besonderer Berücksichtigung des Zusammenhangs zwischen der grundlegenden Oberflächenelektrochemie an Einkristallmodellen und dem abgeleiteten molekularen Designprinzip für reale Elektrokatalysatoren. Indem wir einige typische Beispiele für theoretische Berechnungen, Oberflächencharakterisierungen und elektrochemische Experimente vorstellen, möchten wir einige wichtige anhaltende Diskussionen thematisieren, um zu einem besseren Verständnis der alkalischen HER auf atomarer…

Abstract A mesoporous MnCo 2 O 4 electrode material is made for bifunctional oxygen electrocatalysis. The MnCo 2 O 4 exhibits both Co 3 O 4 ‐like activity for oxygen evolution reaction (OER) and Mn 2 O 3 ‐like performance for oxygen reduction reaction (ORR). The potential difference between the ORR and OER of MnCo 2 O 4 is as low as 0.83 V. By XANES and XPS investigation, the notable activity results from the preferred Mn IV ‐ and Co II ‐rich surface. The electrode material can be obtained on large‐scale with the precise chemical control of the components at relatively low temperature. The surface state engineering may open a new avenue to optimize the electrocatalysis performance of electrode materials. The prominent bifunctional activity shows that MnCo 2 O 4 could be used in metal–air batteries and/or other energy devices.