The 100 most-cited articles in Angewandte Chemie, 2016

Abstract Bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline electrolyte may improve the efficiency of overall water splitting. Nickel cobaltite (NiCo2O4) has been considered a promising electrode material for the OER. However, NiCo2O4 that can be used as an electrocatalyst in HER has not been studied yet. Herein, we report self‐assembled hierarchical NiCo2O4 hollow microcuboids for overall water splitting including both the HER and OER reactions. The NiCo2O4 electrode shows excellent activity toward overall water splitting, with 10 mA cm−2 water‐splitting current reached by applying just 1.65 V and 20 mA cm−2 by applying just 1.74 V across the two electrodes. The synthesis of NiCo2O4 microflowers confirms the importance of structural features for high‐performance overall water splitting.

Abstract Co 3 O 4 , which is of mixed valences Co 2+ and Co 3+ , has been extensively investigated as an efficient electrocatalyst for the oxygen evolution reaction (OER). The proper control of Co 2+ /Co 3+ ratio in Co 3 O 4 could lead to modifications on its electronic and thus catalytic properties. Herein, we designed an efficient Co 3 O 4 ‐based OER electrocatalyst by a plasma‐engraving strategy, which not only produced higher surface area, but also generated oxygen vacancies on Co 3 O 4 surface with more Co 2+ formed. The increased surface area ensures the Co 3 O 4 has more sites for OER, and generated oxygen vacancies on Co 3 O 4 surface improve the electronic conductivity and create more active defects for OER. Compared to pristine Co 3 O 4 , the engraved Co 3 O 4 exhibits a much higher current density and a lower onset potential. The specific activity of the plasma‐engraved Co 3 O 4 nanosheets (0.055 mA cm −2 BET at 1.6 V) is 10 times higher than that of pristine Co 3 O 4 , which is contributed by the surface oxygen vacancies.

Abstract A new super‐concentrated aqueous electrolyte is proposed by introducing a second lithium salt. The resultant ultra‐high concentration of 28 m led to more effective formation of a protective interphase on the anode along with further suppression of water activities at both anode and cathode surfaces. The improved electrochemical stability allows the use of TiO2 as the anode material, and a 2.5 V aqueous Li‐ion cell based on LiMn2O4 and carbon‐coated TiO2 delivered the unprecedented energy density of 100 Wh kg−1 for rechargeable aqueous Li‐ion cells, along with excellent cycling stability and high coulombic efficiency. It has been demonstrated that the introduction of a second salts into the “water‐in‐salt” electrolyte further pushed the energy densities of aqueous Li‐ion cells closer to those of the state‐of‐the‐art Li‐ion batteries.

Abstract Photoluminescence (PL), up‐conversion PL (UCPL), and phosphorescence are three kinds of phenomena common to light‐emitting materials, but it is very difficult to observe all of them simultaneously when they are derived from a single material at room temperature. For the first time, triple‐mode emission (that is, PL, UCPL, and room temperature phosphorescence (RTP)) is reported, which relies on a composite of the luminescent carbon dots (CDs) prepared from m‐phenylenediamine and poly(vinyl alcohol) (PVA). Moreover, the CDs‐PVA aqueous dispersion is nearly colorless and demonstrates promise as a triple‐mode emission ink in the field of advanced anti‐counterfeiting.

Abstract To achieve sustainable production of H2 fuel through water splitting, low‐cost electrocatalysts for the hydrogen‐evolution reaction (HER) and the oxygen‐evolution reaction (OER) are required to replace Pt and IrO2 catalysts. Herein, for the first time, we present the interface engineering of novel MoS2/Ni3S2 heterostructures, in which abundant interfaces are formed. For OER, such MoS2/Ni3S2 heterostructures show an extremely low overpotential of ca. 218 mV at 10 mA cm−2, which is superior to that of the state‐of‐the‐art OER electrocatalysts. Using MoS2/Ni3S2 heterostructures as bifunctional electrocatalysts, an alkali electrolyzer delivers a current density of 10 mA cm−2 at a very low cell voltage of ca. 1.56 V. In combination with DFT calculations, this study demonstrates that the constructed interfaces synergistically favor the chemisorption of hydrogen and oxygen‐containing intermediates, thus accelerating the overall electrochemical water splitting.

Abstract A new strategy for achieving stable Co single atoms (SAs) on nitrogen‐doped porous carbon with high metal loading over 4 wt % is reported. The strategy is based on a pyrolysis process of predesigned bimetallic Zn/Co metal–organic frameworks, during which Co can be reduced by carbonization of the organic linker and Zn is selectively evaporated away at high temperatures above 800 °C. The spherical aberration correction electron microscopy and extended X‐ray absorption fine structure measurements both confirm the atomic dispersion of Co atoms stabilized by as‐generated N‐doped porous carbon. Surprisingly, the obtained Co‐N x single sites exhibit superior ORR performance with a half‐wave potential (0.881 V) that is more positive than commercial Pt/C (0.811 V) and most reported non‐precious metal catalysts. Durability tests revealed that the Co single atoms exhibit outstanding chemical stability during electrocatalysis and thermal stability that resists sintering at 900 °C. Our findings open up a new routine for general and practical synthesis of a variety of materials bearing…

Abstract Considering that the high capacity, long‐term cycle life, and high‐rate capability of anode materials for sodium‐ion batteries (SIBs) is a bottleneck currently, a series of Co‐doped FeS2 solid solutions with different Co contents were prepared by a facile solvothermal method, and for the first time their Na‐storage properties were investigated. The optimized Co0.5Fe0.5S2 (Fe0.5) has discharge capacities of 0.220 Ah g−1 after 5000 cycles at 2 A g−1 and 0.172 Ah g−1 even at 20 A g−1 with compatible ether‐based electrolyte in a voltage window of 0.8–2.9 V. The Fe0.5 sample transforms to layered NaxCo0.5Fe0.5S2 by initial activation, and the layered structure is maintained during following cycles. The redox reactions of NaxCo0.5Fe0.5S2 are dominated by pseudocapacitive behavior, leading to fast Na+ insertion/extraction and durable cycle life. A Na3V2(PO4)3/Fe0.5 full cell was assembled, delivering an initial capacity of 0.340 Ah g−1.

Abstract The development of efficient metal‐free organic emitters with thermally activated delayed fluorescence (TADF) properties for deep‐blue emission is still challenging. A new family of deep‐blue TADF emitters based on a donor–acceptor architecture has been developed. The electronic interaction between donor and acceptor plays a key role in the TADF mechanism. Deep‐blue OLEDs fabricated with these TADF emitters achieved high external quantum efficiencies over 19.2 % with CIE coordinates of (0.148, 0.098).

Abstract Highly crystalline graphitic carbon nitride (g‐C 3 N 4 ) with decreased structural imperfections benefits from the suppression of electron–hole recombination, which enhances its hydrogen generation activity. However, producing such g‐C 3 N 4 materials by conventional heating in an electric furnace has proven challenging. Herein, we report on the synthesis of high‐quality g‐C 3 N 4 with reduced structural defects by judiciously combining the implementation of melamine–cyanuric acid (MCA) supramolecular aggregates and microwave‐assisted thermolysis. The g‐C 3 N 4 material produced after optimizing the microwave reaction time can effectively generate H 2 under visible‐light irradiation. The highest H 2 evolution rate achieved was 40.5 μmol h −1 , which is two times higher than that of a g‐C 3 N 4 sample prepared by thermal polycondensation of the same supramolecular aggregates in an electric furnace. The microwave‐assisted thermolysis strategy is simple, rapid, and robust, thereby providing a promising route for the synthesis of high‐efficiency g‐C 3 N 4 photocatalysts.

Abstract Polymer–ceramic composite electrolytes are emerging as a promising solution to deliver high ionic conductivity, optimal mechanical properties, and good safety for developing high‐performance all‐solid‐state rechargeable batteries. Composite electrolytes have been prepared with cubic‐phase Li7La3Zr2O12 (LLZO) garnet and polyethylene oxide (PEO) and employed in symmetric lithium battery cells. By combining selective isotope labeling and high‐resolution solid‐state Li NMR, we are able to track Li ion pathways within LLZO‐PEO composite electrolytes by monitoring the replacement of 7Li in the composite electrolyte by 6Li from the 6Li metal electrodes during battery cycling. We have provided the first experimental evidence to show that Li ions favor the pathway through the LLZO ceramic phase instead of the PEO‐LLZO interface or PEO. This approach can be widely applied to study ion pathways in ionic conductors and to provide useful insights for developing composite materials for energy storage and harvesting.

Abstract The delamination of titanium carbide sheets, an intriguing class of two‐dimensional materials, has been critically dependent on the extraction of interlayer Al in acidic media, such as concentrated hydrofluoric acid (HF) or a mixture of hydrochloric acid (HCl) and a fluoride salt. Herein, we report an organic‐base‐driven intercalation and delamination of titanium carbide that takes advantage of the amphoteric nature of interlayer Al. The resulting aluminum‐oxoanion‐functionalized titanium carbide sheets manifested unusually strong optical absorption in the near‐infrared (NIR) region with a mass extinction coefficient as high as 29.1 L g−1 cm−1 at 808 nm. Thus, the performance of this material is comparable or even superior to that of state‐of‐the‐art photoabsorption materials, including gold‐based nanostructures, carbon‐based materials, and transition‐metal dichalcogenides. Preliminary studies show that the titanium carbide sheets serve as efficient photothermal agents against tumor cells.

Abstract The direct urea fuel cell (DUFC) is an important but challenging renewable energy production technology, it offers great promise for energy‐sustainable developments and mitigating water contamination. However, DUFCs still suffer from the sluggish kinetics of the urea oxidation reaction (UOR) owing to a 6 e− transfer process, which poses a severe hindrance to their practical use. Herein, taking β‐Ni(OH)2 nanosheets as the proof‐of‐concept study, we demonstrated a surface‐chemistry strategy to achieve metallic Ni(OH)2 nanosheets by engineering their electronic structure, representing a first metallic configuration of transition‐metal hydroxides. Surface sulfur incorporation successfully brings synergetic effects of more exposed active sites, good wetting behavior, and effective electron transport, giving rise to greatly enhanced performance for UOR. Metallic nanosheets exhibited a much higher current density, smaller onset potential and stronger durability.

Abstract Modular optimization of metal–organic frameworks (MOFs) was realized by incorporation of coordinatively unsaturated single atoms in a MOF matrix. The newly developed MOF can selectively capture and photoreduce CO2 with high efficiency under visible‐light irradiation. Mechanistic investigation reveals that the presence of single Co atoms in the MOF can greatly boost the electron–hole separation efficiency in porphyrin units. Directional migration of photogenerated excitons from porphyrin to catalytic Co centers was witnessed, thereby achieving supply of long‐lived electrons for the reduction of CO2 molecules adsorbed on Co centers. As a direct result, porphyrin MOF comprising atomically dispersed catalytic centers exhibits significantly enhanced photocatalytic conversion of CO2, which is equivalent to a 3.13‐fold improvement in CO evolution rate (200.6 μmol g−1 h−1) and a 5.93‐fold enhancement in CH4 generation rate (36.67 μmol g−1 h−1) compared to the parent MOF.

Abstract The ground‐state deprotection of a simple alkynylsilane is studied under vibrational strong coupling to the zero‐point fluctuations, or vacuum electromagnetic field, of a resonant IR microfluidic cavity. The reaction rate decreased by a factor of up to 5.5 when the Si−C vibrational stretching modes of the reactant were strongly coupled. The relative change in the reaction rate under strong coupling depends on the Rabi splitting energy. Product analysis by GC‐MS confirmed the kinetic results. Temperature dependence shows that the activation enthalpy and entropy change significantly, suggesting that the transition state is modified from an associative to a dissociative type. These findings show that vibrational strong coupling provides a powerful approach for modifying and controlling chemical landscapes and for understanding reaction mechanisms.

Abstract TiO2 photoredox catalysis has recently attracted much interest for use in performing challenging organic transformations under mild reaction conditions. However, the reaction scheme is hampered by the fact that TiO2 can only be excited by UV light of wavelengths λ shorter than 385 nm. One promising strategy to overcome this issue is to anchor an organic, preferably metal‐free dye onto the surface of TiO2. Importantly, we observed that the introduction of a catalytic amount of the redox mediator TEMPO [(2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl] ensured the stability of the anchored dye, alizarin red S, thereby resulting in the selective oxidation of organic sulfides with O2. This result affirms the essential role of the redox mediator in enabling the organic transformations by visible‐light photoredox catalysis.

Abstract Aufgrund ihrer strukturellen, chemischen und funktionellen Vielfalt werden Metall‐organische Gerüstverbindungen (MOFs) seit etwa zwei Jahrzehnten für energierelevante Anwendungen erforscht. Bis vor kurzem mangelte es dabei aber an Anwendungen, für die ein guter Ladungstransport zusammen mit Porosität und einer großen Oberfläche erforderlich ist. Die meisten MOFs sind elektrische Isolatoren, und erst unlängst wurde für einige Materialien dieser Klasse ausgezeichnete elektrische Leitfähigkeit und hohe Ladungsmobilität gefunden. In diesem Aufsatz geben wir eine Übersicht über synthetische und elektronische Designstrategien für Gerüste mit permanenter Porosität und Ladungstransport über große Distanzen. Ferner diskutieren wir wegweisende Experimente zum elektrischen Ladungstransport und ausgewählte Anwendungen für diese spezielle Unterklasse von MOFs.

Abstract Rational design of non‐noble materials as highly efficient, economical, and durable bifunctional catalysts for oxygen evolution and reduction reactions (OER/ORR) is currently a critical obstacle for rechargeable metal‐air batteries. A new route involving S was developed to achieve atomic dispersion of Fe‐N x species on N and S co‐decorated hierarchical carbon layers, resulting in single‐atom bifunctional OER/ORR catalysts for the first time. The abundant atomically dispersed Fe‐N x species are highly catalytically active, the hierarchical structure offers more opportunities for active sites, and the electrical conductivity is greatly improved. The obtained electrocatalyst exhibits higher limiting current density and a more positive half‐wave potential for ORR, as well as a lower overpotential for OER under alkaline conditions. Moreover, a rechargeable Zn–air battery device comprising this hybrid catalyst shows superior performance compared to Pt/C catalyst. This work will open a new avenue to design advanced bifunctional catalysts for reversible energy storage and…

Abstract Although persistent room‐temperature phosphorescence (RTP) emission has been observed for a few pure crystalline organic molecules, there is no consistent mechanism and no universal design strategy for organic persistent RTP (pRTP) materials. A new mechanism for pRTP is presented, based on combining the advantages of different excited‐state configurations in coupled intermolecular units, which may be applicable to a wide range of organic molecules. By following this mechanism, we have developed a successful design strategy to obtain bright pRTP by utilizing a heavy halogen atom to further increase the intersystem crossing rate of the coupled units. RTP with a remarkably long lifetime of 0.28 s and a very high quantum efficiency of 5 % was thus obtained under ambient conditions. This strategy represents an important step in the understanding of organic pRTP emission.

Abstract Electrochemical splitting of water to produce hydrogen and oxygen is an important process for many energy storage and conversion devices. Developing efficient, durable, low‐cost, and earth‐abundant electrocatalysts for the oxygen evolution reaction (OER) is of great urgency. To achieve the rapid synthesis of transition‐metal nitride nanostructures and improve their electrocatalytic performance, a new strategy has been developed to convert cobalt oxide precursors into cobalt nitride nanowires through N 2 radio frequency plasma treatment. This method requires significantly shorter reaction times (about 1 min) at room temperature compared to conventional high‐temperature NH 3 annealing which requires a few hours. The plasma treatment significantly enhances the OER activity, as evidenced by a low overpotential of 290 mV to reach a current density of 10 mA cm −2 , a small Tafel slope, and long‐term durability in an alkaline electrolyte.

Abstract Lignin ist ein reichlich vorhandenes Biopolymer mit hohem Kohlenstoffgehalt und hoher Aromatizität. Trotz seines Potenzials als Rohstoff für die Kraftstoffherstellung und die chemische Industrie ist Lignin noch immer das am wenigsten genutzte Biopolymer der Lignocellulose. Zur effektiven Aufwertung von Lignin ist eine sorgfältige Feinabstimmung mehrerer vorgeschalteter Prozessstufen (d. h. Biotechnik von Lignin, Abtrennung von Lignin und katalytische Umwandlung von Lignin in der Anfangsphase) und mehrerer nachgeschalteter Prozessstufen (d. h. Depolymerisation und Verwertung von Lignin) erforderlich, die den Einsatz und das Zusammenwirken eines breiten Spektrums wissenschaftlicher Disziplinen erfordert. Dieser Aufsatz liefert eine Analyse der neuesten Fortschritte bei der Verwertung von Lignin “vom Anfang bis zum Ende”. Besonderes Augenmerk liegt auf dem verbesserten Verständnis der Biosynthese und Struktur von Lignin, den Unterschieden in Struktur und chemischer Bindung zwischen nativen und technischen Ligninen, den neu aufkommenden Verfahren der katalytischen Verwertung…

Abstract Methanol synthesis by CO 2 hydrogenation is attractive in view of avoiding the environmental implications associated with the production of the traditional syngas feedstock and mitigating global warming. However, there still is a lack of efficient catalysts for such alternative processes. Herein, we unveil the high activity, 100 % selectivity, and remarkable stability for 1000 h on stream of In 2 O 3 supported on ZrO 2 under industrially relevant conditions. This strongly contrasts to the benchmark Cu‐ZnO‐Al 2 O 3 catalyst, which is unselective and experiences rapid deactivation. In‐depth characterization of the In 2 O 3 ‐based materials points towards a mechanism rooted in the creation and annihilation of oxygen vacancies as active sites, whose amount can be modulated in situ by co‐feeding CO and boosted through electronic interactions with the zirconia carrier. These results constitute a promising basis for the design of a prospective technology for sustainable methanol production.

Während es schon viele Metallabenzole gibt , existieren bislang als Metalla-Analoga der linearen polycyclischen Kohlenwasserstoffe nur ein paar Metallanaphthaline. L. J. Wright und B. J. Frogley beschreiben in der Zuschrift auf S. 149 ff. nun das erste Metallaanthracen, das als Vorstufe für andere neue Metallaarene dient. Im Bild (in dem Iridium und seine Hilfsliganden die Augen sind) schildert der Cartoonist Nick Kim die “Evolution” polycyclischer Metallaarene bis hin zur Bildung einer Iridaanthrachinon-“Tochter”.

Abstract Dieser Aufsatz diskutiert die Chancen und Herausforderungen für die Nutzung der Kombination aus Kohlendioxid und Wasserstoff als C1‐Synthon in katalytischen Reaktionen und Prozessen. Die Transformationen werden anhand des Reduktionsgrades und der Bindungsknüpfung geordnet, wobei die chemische Wertschöpfungskette von großvolumigen Grundchemikalien bis hin zu komplexen Molekülen mit biologischer Wirkung abgedeckt wird. Die chemischen Transformationen erlauben zum einen die Speicherung und Nutzung von erneuerbaren Energien in stofflichen Produkten und bieten gleichzeitig Möglichkeiten für ressourcenschonende und umweltfreundliche Herstellungsprozesse. Interdisziplinäre Grundlagenforschung von Chemikern und Ingenieuren kann so zu nachhaltigen Technologien an der Schnittstelle von Energie und Chemie beitragen. Der Aufsatz lädt den Leser dazu ein, das “katalytische Schachbrett” der Nutzung von CO2 und H2 kennenzulernen und vielleicht selbst einige Partien darauf zu beginnen.

Abstract Die Katalyse mit N‐heterocyclischen Carbenen (NHC) hat sich in der organischen Synthese zu einer leistungsfähigen Strategie entwickelt, um komplexe Moleküle hauptsächlich durch Umpolungsverfahren aufzubauen. Diese einzigartigen Lewis‐Basen wurden verwendet, um Acylanionen, Enolate und Homoenolate katalytisch zu generieren. Kürzlich wurde eine neue Strategie entwickelt, mit der die Anwendbarkeit der Carbenkatalyse bei Synthesen durch den wirksamen Einsatz zusätzlicher Aktivierungsarten erheblich erweitert werden konnte: die kooperative Katalyse. Durch die sorgfältige Auswahl von Cokatalysatoren können Reaktivitäten, Ausbeuten und Stereoselektivitäten verbessert werden. In einigen Fällen haben diese katalytischen Additive die Regioselektivität oder Diastereoselektivität verändert. In diesem Kurzaufsatz werden die neuesten Fortschritte bei der kooperativen Katalyse mit NHCs herausgestellt und die Gesamtentwicklung des Gebiets betrachtet.

Abstract In this work, the selective electrocatalytic reduction of carbon dioxide to carbon monoxide on oxide‐derived silver electrocatalysts is presented. By a simple synthesis technique, the overall high faradaic efficiency for CO production on the oxide‐derived Ag was shifted by more than 400 mV towards a lower overpotential compared to that of untreated Ag. Notably, the Ag resulting from Ag oxide is capable of electrochemically reducing CO2 to CO with approximately 80 % catalytic selectivity at a moderate overpotential of 0.49 V, which is much higher than that (ca. 4 %) of untreated Ag under identical conditions. Electrokinetic studies show that the improved catalytic activity is ascribed to the enhanced stabilization of COOH. intermediate. Furthermore, highly nanostructured Ag is likely able to create a high local pH near the catalyst surface, which may also facilitate the catalytic activity for the reduction of CO2 with suppressed H2 evolution.

Abstract It is highly attractive but challenging to develop earth‐abundant electrocatalysts for energy‐saving electrolytic hydrogen generation. Herein, we report that Ni2P nanoarrays grown in situ on nickel foam (Ni2P/NF) behave as a durable high‐performance non‐noble‐metal electrocatalyst for hydrazine oxidation reaction (HzOR) in alkaline media. The replacement of the sluggish anodic oxygen evolution reaction with such the more thermodynamically favorable HzOR enables energy‐saving electrochemical hydrogen production with the use of Ni2P/NF as a bifunctional catalyst for anodic HzOR and cathodic hydrogen evolution reaction. When operated at room temperature, this two‐electrode electrolytic system drives 500 mA cm−2 at a cell voltage as low as 1.0 V with strong long‐term electrochemical durability and 100 % Faradaic efficiency for hydrogen evolution in 1.0 m KOH aqueous solution with 0.5 m hydrazine.

Abstract Extraction of lithium ions from salt‐lake brines is very important to produce lithium compounds. Herein, we report a new approach to construct polystyrene sulfonate (PSS) threaded HKUST‐1 metal–organic framework (MOF) membranes through an in situ confinement conversion process. The resulting membrane PSS@HKUST‐1‐6.7, with unique anchored three‐dimensional sulfonate networks, shows a very high Li+ conductivity of 5.53×10−4 S cm−1 at 25 °C, 1.89×10−3 S cm−1 at 70 °C, and Li+ flux of 6.75 mol m−2 h−1, which are five orders higher than that of the pristine HKUST‐1 membrane. Attributed to the different size sieving effects and the affinity differences of the Li+, Na+, K+, and Mg2+ ions to the sulfonate groups, the PSS@HKUST‐1‐6.7 membrane exhibits ideal selectivities of 78, 99, and 10296 for Li+/Na+, Li+/K+, Li+/Mg2+ and real binary ion selectivities of 35, 67, and 1815, respectively, the highest ever reported among ionic conductors and Li+ extraction membranes.

Abstract Metallic glasses and cancer theranostics are emerging fields that do not seem to be related to each other. Herein, we report the facile synthesis of amorphous iron nanoparticles (AFeNPs) and their superior physicochemical properties compared to their crystalline counterpart, iron nanocrystals (FeNCs). The AFeNPs can be used for cancer theranostics by inducing a Fenton reaction in the tumor by taking advantage of the mild acidity and the overproduced H 2 O 2 in a tumor microenvironment: Ionization of the AFeNPs enables on‐demand ferrous ion release in the tumor, and subsequent H 2 O 2 disproportionation leads to efficient . OH generation. The endogenous stimuli‐responsive . OH generation in the presence AFeNPs enables a highly specific cancer therapy without the need for external energy input.

Abstract Electrochemical reduction of CO2 into liquid fuels is a promising approach to achieve a carbon‐neutral energy cycle. However, conventional electrocatalysts usually suffer from low energy efficiency and poor selectivity and stability. A 3D hierarchical structure composed of mesoporous SnO2 nanosheets on carbon cloth is proposed to efficiently and selectively electroreduce CO2 to formate in aqueous media. The electrode is fabricated by a facile combination of hydrothermal reaction and calcination. It exhibits an unprecedented partial current density of about 45 mA cm−2 at a moderate overpotential (0.88 V) with high faradaic efficiency (87±2 %), which is even larger than most gas diffusion electrodes. Additionally, the electrode also demonstrates flexibility and long‐term stability. The superior performance is attributed to the robust and highly porous hierarchical structure, which provides a large surface area and facilitates charge and mass transfer.

Abstract Composite nanomaterials usually possess synergetic properties resulting from the respective components and can be used for a wide range of applications. In this work, a Pd nanocubes@ZIF‐8 composite material has been rationally fabricated by encapsulation of the Pd nanocubes in ZIF‐8, a common metal–organic framework (MOF). This composite was used for the efficient and selective catalytic hydrogenation of olefins at room temperature under 1 atm H 2 and light irradiation, and benefits from plasmonic photothermal effects of the Pd nanocube cores while the ZIF‐8 shell plays multiple roles; it accelerates the reaction by H 2 enrichment, acts as a “molecular sieve” for olefins with specific sizes, and stabilizes the Pd cores. Remarkably, the catalytic efficiency of a reaction under 60 mW cm −2 full‐spectrum or 100 mW cm −2 visible‐light irradiation at room temperature turned out to be comparable to that of a process driven by heating at 50 °C. Furthermore, the catalyst remained stable and could be easily recycled. To the best of our knowledge, this work represents the first…

Abstract A titanium sulfonate ligand is synthesized for surface coordination of black phosphorus (BP). In contrast to serious degradation observed from the bare BP, the BP after surface coordination exhibits excellent stability during dispersion in water and exposure to air for a long period of time, thereby significantly extending the lifetime and spurring broader application of BP.

Abstract We report a supramolecular strategy to prepare conductive hydrogels with outstanding mechanical and electrochemical properties, which are utilized for flexible solid‐state supercapacitors (SCs) with high performance. The supramolecular assembly of polyaniline and polyvinyl alcohol through dynamic boronate bond yields the polyaniline–polyvinyl alcohol hydrogel (PPH), which shows remarkable tensile strength (5.3 MPa) and electrochemical capacitance (928 F g −1 ). The flexible solid‐state supercapacitor based on PPH provides a large capacitance (306 mF cm −2 and 153 F g −1 ) and a high energy density of 13.6 Wh kg −1 , superior to other flexible supercapacitors. The robustness of the PPH‐based supercapacitor is demonstrated by the 100 % capacitance retention after 1000 mechanical folding cycles, and the 90 % capacitance retention after 1000 galvanostatic charge–discharge cycles. The high activity and robustness enable the PPH‐based supercapacitor as a promising power device for flexible electronics.

Abstract Improving the efficiency of electron–hole separation and charge‐carrier utilization plays a central role in photocatalysis. Herein, Pt nanoparticles of ca. 3 nm are incorporated inside or supported on a representative metal–organic framework (MOF), UiO‐66‐NH2, denoted as Pt@UiO‐66‐NH2 and Pt/UiO‐66‐NH2, respectively, for photocatalytic hydrogen production via water splitting. Compared with the pristine MOF, both Pt‐decorated MOF nanocomposites exhibit significantly improved yet distinctly different hydrogen‐production activities, highlighting that the photocatalytic efficiency strongly correlates with the Pt location relative to the MOF. The Pt@UiO‐66‐NH2 greatly shortens the electron‐transport distance, which favors the electron–hole separation and thereby yields much higher efficiency than Pt/UiO‐66‐NH2. The involved mechanism has been further unveiled by means of ultrafast transient absorption and photoluminescence spectroscopy.

Abstract Herein, we developed FeOOH/Co/FeOOH hybrid nanotube arrays (HNTAs) supported on Ni foams for oxygen evolution reaction (OER). The inner Co metal cores serve as highly conductive layers to provide reliable electronic transmission, and can overcome the poor electrical conductivity of FeOOH efficiently. DFT calculations demonstrate the strong electronic interactions between Co and FeOOH in the FeOOH/Co/FeOOH HNTAs, and the hybrid structure can lower the energy barriers of intermediates and thus promote the catalytic reactions. The FeOOH/Co/FeOOH HNTAs exhibit high electrocatalytic performance for OER, such as low onset potential, small Tafel slope, and excellent long‐term durability, and they are promising electrocatalysts for OER in alkaline solution.

Abstract Room‐temperature sodium‐ion batteries (SIBs) have shown great promise in grid‐scale energy storage, portable electronics, and electric vehicles because of the abundance of low‐cost sodium. Sodium‐based layered oxides with a P2‐type layered framework have been considered as one of the most promising cathode materials for SIBs. However, they suffer from the undesired P2–O2 phase transition, which leads to rapid capacity decay and limited reversible capacities. Herein, we show that this problem can be significantly mitigated by substituting some of the nickel ions with magnesium to obtain Na 0.67 Mn 0.67 Ni 0.33− x Mg x O 2 (0≤ x ≤0.33). Both the reversible capacity and the capacity retention of the P2‐type cathode material were remarkably improved as the P2–O2 phase transition was thus suppressed during cycling. This strategy might also be applicable to the modulation of the physical and chemical properties of layered oxides and provides new insight into the rational design of high‐capacity and highly stable cathode materials for SIBs.

Abstract Polydopamine (PDA), which is biodegradable and is derived from naturally occurring products, can be employed as an electrode material, wherein controllable partial oxidization plays a key role in balancing the proportion of redox‐active carbonyl groups and the structural stability and conductivity. Unexpectedly, the optimized PDA derivative endows lithium‐ion batteries (LIBs) or sodium‐ion batteries (SIBs) with superior electrochemical performances, including high capacities (1818 mAh g−1 for LIBs and 500 mAh g−1 for SIBs) and good stable cyclabilities (93 % capacity retention after 580 cycles for LIBs; 100 % capacity retention after 1024 cycles for SIBs), which are much better than those of their counterparts with conventional binders.

Abstract The direct synthesis of lower (C 2 to C 4 ) olefins, key building‐block chemicals, from syngas (H 2 /CO), which can be derived from various nonpetroleum carbon resources, is highly attractive, but the selectivity for lower olefins is low because of the limitation of the Anderson–Schulz–Flory distribution. We report that the coupling of methanol‐synthesis and methanol‐to‐olefins reactions with a bifunctional catalyst can realize the direct conversion of syngas to lower olefins with exceptionally high selectivity. We demonstrate that the choice of two active components and the integration manner of the components are crucial to lower olefin selectivity. The combination of a Zr–Zn binary oxide, which alone shows higher selectivity for methanol and dimethyl ether even at 673 K, and SAPO‐34 with decreased acidity offers around 70 % selectivity for C 2 –C 4 olefins at about 10 % CO conversion. The micro‐ to nanoscale proximity of the components favors the lower olefin selectivity.

Abstract Die selektive C‐H‐Aktivierung an einer einzigen und strategisch wichtigen Position in Gegenwart von zahlreichen weiteren C‐H‐Bindungen kann einen leistungsfähigen und allgemein nützlichen Schritt in der Syntheseplanung darstellen. In diesem Zusammenhang dient die dirigierende Gruppe als ein “Kompass”, um – mittels Abständen und Geometrien als Erkennungsparameter zur Unterscheidung zwischen proximalen und distalen C‐H‐Bindungen – das Übergangmetall an C‐H‐Bindungen zu lenken. Die Einführung und Abspaltung dirigierender Gruppen ist allerdings ein Nachteil für die Synthesepraxis. Um diese Ansätze nützlicher zu gestalten, kann man in drei Richtungen nach Lösungen suchen. Erstens, durch Vereinfachung der dirigierenden Gruppe; zweitens, durch Verwendung von gängigen funktionellen Gruppen oder Schutzgruppen als dirigierende Gruppen; drittens, durch Anbindung der dirigierenden Gruppe an Substrate über eine transiente kovalente Bindung, um die dirigierende Gruppe zu einem Katalysator zu machen. Dieser Aufsatz beschreibt die rationale Entwicklung einer sehr einfachen und dennoch…

Abstract Polymer‐derived carbon aerogels can be obtained by direct polymerization of monomers under hypersaline conditions using inorganic salts. This allows for significantly increased mechanical robustness and avoiding special drying processes. This concept was realized by conducting the polymerization of phenol–formaldehyde (PF) in the presence of ZnCl2 salt. Afterwards, the simultaneous carbonization and foaming process conveniently converts the PF monolith into a foam‐like carbon aerogel. ZnCl2 plays a key role, serving as dehydration agent, foaming agent, and porogen. The carbon aerogels thus obtained are of very low density (25 mg cm−3), high specific surface area (1340 m2 g−1), and have a large micro‐ and mesopore volume (0.75 cm3 g−1). The carbon aerogels show very promising potential in the separation/extraction of organic pollutants and for energy storage.

Abstract This paper describes a sintering technique for ceramics and ceramic‐based composites, using water as a transient solvent to effect densification (i.e. sintering) at temperatures between room temperature and 200 °C. To emphasize the incredible reduction in sintering temperature relative to conventional thermal sintering this new approach is named the “Cold Sintering Process” (CSP). Basically CSP uses a transient aqueous environment to effect densification by a mediated dissolution–precipitation process. CSP of NaCl, alkali molybdates and V 2 O 5 with small concentrations of water are described in detail, but the process is extended and demonstrated for a diverse range of chemistries (oxides, carbonates, bromides, fluorides, chlorides and phosphates), multiple crystal structures, and multimaterial applications. Furthermore, the properties of selected CSP samples are demonstrated to be essentially equivalent as samples made by conventional thermal sintering.

Abstract Mussel‐inspired polydopamine (PDA) deposition offers a promising route to fabricate multifunctional coatings for various materials. However, PDA deposition is generally a time‐consuming process, and PDA coatings are unstable in acidic and alkaline media, as well as in polar organic solvents. We report a strategy to realize the rapid deposition of PDA by using CuSO4/H2O2 as a trigger. Compared to the conventional processes, our strategy shows the fastest deposition rate reported to date, and the PDA coatings exhibit high uniformity and enhanced stability. Furthermore, the PDA‐coated porous membranes have excellent hydrophilicity, anti‐oxidant properties, and antibacterial performance. This work demonstrates a useful method for the environmentally friendly, cost‐effective, and time‐saving fabrication of PDA coatings.

Abstract We report a monometallic dysprosium complex, [Dy(OtBu)2(py)5][BPh4] (5), that shows the largest effective energy barrier to magnetic relaxation of Ueff=1815(1) K. The massive magnetic anisotropy is due to bis‐trans‐disposed tert‐butoxide ligands with weak equatorial pyridine donors, approaching proposed schemes for high‐temperature single‐molecule magnets (SMMs). The blocking temperature, TB , is 14 K, defined by zero‐field‐cooled magnetization experiments, and is the largest for any monometallic complex and equal with the current record for [Tb2N2{N(SiMe3)2}4(THF)2].

Abstract Electrocatalysts are required for clean energy technologies (for example, water‐splitting and metal‐air batteries). The development of a multifunctional electrocatalyst composed of nitrogen, phosphorus, and fluorine tri‐doped graphene is reported, which was obtained by thermal activation of a mixture of polyaniline‐coated graphene oxide and ammonium hexafluorophosphate (AHF). It was found that thermal decomposition of AHF provides nitrogen, phosphorus, and fluorine sources for tri‐doping with N, P, and F, and simultaneously facilitates template‐free formation of porous structures as a result of thermal gas evolution. The resultant N, P, and F tri‐doped graphene exhibited excellent electrocatalytic activities for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). The trifunctional metal‐free catalyst was further used as an OER–HER bifunctional catalyst for oxygen and hydrogen gas production in an electrochemical water‐splitting unit, which was powered by an integrated Zn–air battery based on an air electrode made from…

Abstract A meticulously designed, polar, non‐centrosymmetric lead borate chloride, Pb2BO3Cl, was synthesized using KBe2BO3F2 (KBBF) as a model. Single‐crystal X‐ray diffraction revealed that the structure of Pb2BO3Cl consists of cationic [Pb2(BO3)]+ honeycomb layers and Cl− anions. Powder second harmonic generation (SHG) measurements on graded polycrystalline Pb2BO3Cl indicated that the title compound is phase‐matchable (type I) and exhibits a remarkably strong SHG response, which is approximately nine times stronger than that of potassium dihydrogen phosphate, and the largest efficiency observed in materials with structures similar to KBBF. Further characterization suggested that the compound melts congruently at high temperature and has a wide transparency window from the near‐UV to the mid‐IR region.

Abstract Die außerordentliche Zunahme der Zahl katalytischer Umwandlungen über eine metallvermittelte Aktivierung von zuvor als inert angesehenen C‐H‐Bindungen zeugt von einem grundlegenden Wandel auf dem Gebiet der Synthesechemie. Während die meisten Reaktionen mit C‐H‐Aktivierung einfache Funktionalisierungen oder Additionen sind, wuchs in den letzten Jahren das Interesse an verwandten Umwandlungen, die formal als Cycloadditionsprozesse betrachtet werden können. Diese Reaktionen sind besonders für die Synthese vielversprechend, da sie die schnelle und nachhaltige Umwandlung leicht zugänglicher Substrate in wertvolle cyclische Produkte ermöglichen. In vielen Fällen entstehen bei diesen Anellierungsreaktionen metallacyclische Intermediate, die denen der herkömmlichen metallkatalysierten Cycloadditionen ungesättigter Vorstufen ähneln.

Abstract The polarity reversal (umpolung) reaction is an invaluable tool for reversing the chemical reactivity of carbonyl and iminyl groups, which subsequent cross‐coupling reactions to form C−C bonds offers a unique perspective in synthetic planning and implementation. Reported herein is the first visible‐light‐induced polarity‐reversed allylation and intermolecular Michael addition reaction of aldehydes, ketones, and imines. This chemoselective reaction has broad substrate scope and the engagement of alkyl imines is reported for the first time. The mechanistic investigations indicate the formation of ketyl (or α‐aminoalkyl) radicals from single‐electron reduction, where the Hantzsch ester is crucial as the electron/proton donor and the activator.

Abstract Constructing heterostructures can endow materials with fascinating performance in high‐speed electronics, optoelectronics, and other applications owing to the built‐in charge‐transfer driving force, which is of benefit to the specific charge‐transfer kinetics. Rational design and controllable synthesis of nano‐heterostructure anode materials with high‐rate performance, however, still remains a great challenge. Herein, ultrafine SnS/SnO2 heterostructures were successfully fabricated and showed enhanced charge‐transfer capability. The mobility enhancement is attributed to the interface effect of heterostructures, which induces an electric field within the nanocrystals, giving them much lower ion‐diffusion resistance and facilitating interfacial electron transport.

Abstract In this work, the effect of Cu nanowire morphology on the selective electrocatalytic reduction of CO2 is presented. Cu nanowire arrays were prepared through a two‐step synthesis of Cu(OH)2 and CuO nanowire arrays on Cu foil substrates and a subsequent electrochemical reduction of the CuO nanowire arrays to Cu nanowire arrays. By this simple synthesis method, Cu nanowire array electrodes with different length and density were able to be controllably synthesized. We show that the selectivity for hydrocarbons (ethylene, n‐propanol, ethane, and ethanol) on Cu nanowire array electrodes at a fixed potential can be tuned by systematically altering the Cu nanowire length and density. The nanowire morphology effect is linked to the increased local pH in the Cu nanowire arrays and a reaction scheme detailing the local pH‐induced formation of C2 products is also presented by a preferred CO dimerization pathway.

Abstract All‐solid‐state sodium‐ion batteries that operate at room temperature are attractive candidates for use in large‐scale energy storage systems. However, materials innovation in solid electrolytes is imperative to fulfill multiple requirements, including high conductivity, functional synthesis protocols for achieving intimate ionic contact with active materials, and air stability. A new, highly conductive (1.1 mS cm−1 at 25 °C, Ea=0.20 eV) and dry air stable sodium superionic conductor, tetragonal Na3SbS4, is described. Importantly, Na3SbS4 can be prepared by scalable solution processes using methanol or water, and it exhibits high conductivities of 0.1–0.3 mS cm−1. The solution‐processed, highly conductive solidified Na3SbS4 electrolyte coated on an active material (NaCrO2) demonstrates dramatically improved electrochemical performance in all‐solid‐state batteries.

Abstract In den vergangenen Jahren hat die Chemie niedermolekularer Verbindungen mit elektronenpräzisen Bor‐Bor‐Bindungen große Fortschritte gemacht. Dieser Aufsatz bietet eine Übersicht über die neuesten Methoden zur kontrollierten Synthese von B‐B‐Einfach‐ und B‐B‐Mehrfachbindungen sowie über den immer größer werdenden Reaktivitätsumfang von B‐B‐Mehrfachbindungen.

Abstract Lithium–sulfur (Li–S) batteries have been recognized as promising substitutes for current energy‐storage technologies owing to their exceptional advantage in energy density. The main challenge in developing highly efficient and long‐life Li–S batteries is simultaneously suppressing the shuttle effect and improving the redox kinetics. Polar host materials have desirable chemisorptive properties to localize the mobile polysulfide intermediates; however, the role of their electrical conductivity in the redox kinetics of subsequent electrochemical reactions is not fully understood. Conductive polar titanium carbides (TiC) are shown to increase the intrinsic activity towards liquid–liquid polysulfide interconversion and liquid–solid precipitation of lithium sulfides more than non‐polar carbon and semiconducting titanium dioxides. The enhanced electrochemical kinetics on a polar conductor guided the design of novel hybrid host materials of TiC nanoparticles grown within a porous graphene framework (TiC@G). With a high sulfur loading of 3.5 mg cm−2, the TiC@G/sulfur composite…

Abstract Konjugierte Polymere mit vollständiger π‐Konjugation stellen eine neue Generation heterogener Photokatalysatoren für die Nutzung von Solarenergie dar. Sie zeichnen sich durch drei wesentliche Merkmale aus, die für photokatalytische Prozesse wichtig sind, nämlich Robustheit, Ungiftigkeit und ihre Aktivität bei Bestrahlung mit sichtbarem Licht. Dies macht sie zu attraktiven Kandidaten für die Produktion im Großmaßstab. Dieser Kurzaufsatz gibt eine Zusammenfassung der aktuellen Entwicklung verschiedener vielversprechender Polymerphotokatalysatoren für die Wasserstoffentwicklung aus wässrigen Lösungen und geht dabei auch auf lineare Polymere, planarisierte Polymere, Triazin‐/Heptazin‐Polymere und andere verwandte konjugierte organische Halbleiter ein. Besonderes Augenmerk soll auf die rationale Beeinflussung der Zusammensetzung, der Architektur sowie der optischen und elektronischen Eigenschaften gelegt werden, die für die photophysikalischen und photochemischen Eigenschaften relevant sind. Einige Trends und die Zukunftsaussichten für konjugierte organische Photokatalysatoren…

Abstract Two‐dimensional (2D) boron sheets have been successfully synthesized in recent experiments, however, some important issues remain, including the dynamical instability, high energy, and the active surface of the sheets. In an attempt to stabilize 2D boron layers, we have used density functional theory and global minimum search with the particle‐swarm optimization method to predict four stable 2D boron hydride layers, namely the C2/m, Pbcm, Cmmm, and Pmmn sheets. The vibrational normal mode calculations reveal all these structures are dynamically stable, indicating potential for successful experimental synthesis. The calculated Young's modulus indicates a high mechanical strength for the C2/m and Pbcm phases. Most importantly, the C2/m, Pbcm, and Pmmn structures exhibit Dirac cones with massless Dirac fermions and the Fermi velocities for the Pbcm and Cmmm structures are even higher than that of graphene. The Cmmm phase is reported as the first discovery of Dirac ring material among boron‐based 2D structures. The unique electronic structure of the 2D boron hydride sheets…

Abstract Das Feld der Photopharmakologie nutzt durch Licht schaltbare Moleküle, um Kontrolle über die Wirkung biologisch aktiver Verbindungen zu erlangen. Das Ziel ist es, die systemische Toxizität von Wirkstoffen wie auch die Herausbildung von Resistenzen zu vermindern und gleichzeitig eine extrem hohe Präzision in der Behandlung zu erreichen. Durch die Verwendung niedermolekularer Verbindungen stellt die Photopharmakologie eine valide Alternative zur Optogenetik dar. Wir präsentieren hier einen Überblick über die pharmakologischen Zielstrukturen in verschiedenen Organen sowie über Organsysteme im menschlichen Körper, die auf nicht‐invasive Weise angesteuert werden können. Wir diskutieren die Perspektiven einer selektiven Lichtzuführung zu diesen Organen sowie die spezifischen Anforderungen lichtaktivierbarer Wirkstoffe. Über anwendungsorientierte Aspekte hinaus sind wir bestrebt, die Wirkstofftauglichkeit (“druggability”) pharmazeutischer Zielstrukturen anhand aktueller Ergebnisse zu illustrieren. Ferner wollen wir aufzeigen, an welchen Stellen neue Ansätze erforscht werden…

Abstract Favoring the CO2 reduction reaction (CO2RR) over the hydrogen evolution reaction and controlling the selectivity towards multicarbon products are currently major scientific challenges in sustainable energy research. It is known that the morphology of the catalyst can modulate catalytic activity and selectivity, yet this remains a relatively underexplored area in electrochemical CO2 reduction. Here, we exploit the material tunability afforded by colloidal chemistry to establish unambiguous structure/property relations between Cu nanocrystals and their behavior as electrocatalysts for CO2 reduction. Our study reveals a non‐monotonic size‐dependence of the selectivity in cube‐shaped copper nanocrystals. Among 24 nm, 44 nm and 63 nm cubes tested, the cubes with 44 nm edge length exhibited the highest selectivity towards CO2RR (80 %) and faradaic efficiency for ethylene (41 %). Statistical analysis of the surface atom density suggests the key role played by edge sites in CO2RR.

Abstract The pore size enlargement and structural stability have been recognized as two crucial targets, which are rarely achieved together, in the development of metal–organic frameworks (MOFs). Herein, we have developed a versatile modulator‐induced defect‐formation strategy, in the presence of monocarboxylic acid as a modulator and an insufficient amount of organic ligand, successfully realizing the controllable synthesis of hierarchically porous MOFs (HP‐MOFs) with high stability and tailorable pore characters. Remarkably, the integration of high stability and large mesoporous property enables these HP‐MOFs to be important porous platforms for applications involving large molecules, especially in catalysis.

Abstract A pyridinebis(oxazoline) cobalt complex is a very efficient precatalyst for the hydrosilylation of terminal alkynes with Ph2SiH2, providing α‐vinylsilanes with high (Markovnikov) regioselectivity and broad functional‐group tolerance. The vinylsilane products can be further converted into geminal borosilanes through Markovnikov hydroboration with pinacolborane and a bis(imino)pyridine cobalt catalyst.

Abstract Herein, a series of porous nano‐structured carbocatalysts have been fused and decorated by Mo‐based composites, such as Mo2C, MoN, and MoP, to form a hybrid structures. Using the open porosity derived from the pyrolysis of metal–organic frameworks (MOFs), the highly dispersive MoO2 small nanoparticles can be deposited in porous carbon by chemical vapor deposition (CVD). Undergoing different treatments of carbonization, nitridation, and phosphorization, the Mo2C‐, MoN‐, and MoP‐decorated carbocatalysts can be selectively prepared with un‐changed morphology. Among these Mo‐based composites, the MoP@Porous carbon (MoP@PC) composites exhibited remarkable catalytic activity for the hydrogen evolution reaction (HER) in 0.5 m H2SO4 aqueous solution versus MoO2@PC, Mo2C@PC, and MoN@PC. This study gives a promising family of multifunctional lab‐on‐a‐particle architectures which shed light on energy conversion and fuel‐cell catalysis.

Abstract Black phosphorus (BP) as a new 2D material has attracted extensive attention because of its unique electronic, optical, and structural properties. However, the difficulties associated with BP synthesis severely hinder the further development of BP for any potential applications. On the other hand, searching for other potential applications of BP is also a big challenge. A facile strategy was developed for preparation of BP supported on Ti foil (BP‐Ti) in a thin‐film form. Surprisingly, the as‐prepared BP shows advanced electrocatalytic activity for the oxygen evolution reaction (OER). To improve the OER activity of the electrocatalyst, BP was grown on a carbon nanotube network (BP‐CNT), showing even better activity. The results demonstrate that BP can be prepared by a facile method and may be applied as an electrocatalyst.

Abstract Hypervalente Iodverbindungen nehmen als Reagentien in der organischen Synthese aufgrund ihrer außergewöhnlichen Reaktivität eine Sonderstellung ein. Unter ihnen ragen cyclische Derivate wegen ihrer erhöhten Stabilität heraus. Sie finden zwar weitreichende Anwendung als Oxidationsmittel, die Erforschung ihrer Möglichkeiten zum Transfer funktioneller Gruppen begann jedoch erst kürzlich. Während die Verwendung von Benziodoxol(on)en zur Trifluormethylierung (Togni‐Reagens) schon weitgehend anerkannt ist, erfuhren vor kurzem auch andere Transformationen große Aufmerksamkeit. Der vorliegende Aufsatz bespricht die Entwicklungen auf diesem Gebiet seit 2011. Nach einer kurzen Zusammenfassung der Methoden zur Synthese von Benziodoxol(on)reagentien wird ihre Verwendung zum Aufbau von Kohlenstoff‐Heteroatom‐ und Kohlenstoff‐Kohlenstoff‐Bindungen diskutiert. Äußerst erfolgreich war die Einführung von Alkinen mithilfe von Ethinylbenziodoxol(on)(EBX)‐Reagentien. Durchbrüche bei der Einführung von Alkoxy‐, Azido‐, Difluormethyl‐ und Cyangruppen werden ebenfalls vorgestellt.

Abstract Graphitic carbon nitride (g‐C3N4) has been used as photosensitizer to generate reactive oxygen species (ROS) for photodynamic therapy (PDT). However, its therapeutic efficiency was far from satisfactory. One of the major obstacles was the overexpression of glutathione (GSH) in cancer cells, which could diminish the amount of generated ROS before their arrival at the target site. Herein, we report that the integration of Cu2+ and g‐C3N4 nanosheets (Cu2+–g‐C3N4) led to enhanced light‐triggered ROS generation as well as the depletion of intracellular GSH levels. Consequently, the ROS generated under light irradiation could be consumed less by reduced GSH, and efficiency was improved. Importantly, redox‐active species Cu+–g‐C3N4 could catalyze the reduction of molecular oxygen to the superoxide anion or hydrogen peroxide to the hydroxyl radical, both of which facilitated the generation of ROS. This synergy of improved ROS generation and GSH depletion could enhance the efficiency of PDT for cancer therapy.

Abstract Polymermembranen sind ein energieeffizientes Mittel zur Aufbereitung von Wasser, ein Problem ist jedoch das Auftreten von Fouling während der Filtration. Ein Weg, Membran‐Fouling zu umgehen, ist die Modifizierung der Membranoberfläche, um eine höhere Wasserproduktivität aufrechtzuerhalten. Wir diskutieren hier eine Reihe gängiger Membranoberflächenmodifizierungstechniken, darunter Oberflächenbeschichtungen und Pfropfen, sowie verschiedene Behandlungsmethoden wie etwa chemische Behandlungen, UV‐Bestrahlung und Plasma‐Behandlungen. Die Diskussion wird in den historischen Hintergrund der Membranentwicklung und Oberflächenmodifizierung eingebunden. Wir stellen außerdem Polydopamin als ein neu entwickeltes Material für die Membranmodifizierung vor, das sich in einfacher Weise auf einer Vielzahl von Substraten aufbringen lässt.

Abstract Ein langfristiges Ziel der organischen Synthesechemie und der Nanokohlenstoffchemie ist die selektive und vorhersagbare Synthese von strukturell gleichförmigen Kohlenstoffnanoröhren (CNTs). Dieser Aufsatz konzentriert sich auf synthetische Arbeiten, die dieses Ziel einer gesteuerten Synthese von chiralen CNTs durch die organische Synthese von CNT‐Segmenten und mithilfe eines durch organische Template vermittelten CNT‐Wachstums in Reichweite bringen.

Abstract Katalysatoren, deren Aktivität und Selektivität durch externe Stimuli reguliert wird, können die effiziente mehrstufige Synthese von komplexen Molekülen und Pharmazeutika ermöglichen. Hier wird über die Regulation des Redoxpotentials eines Photokatalysators zur kontrollierten Aktivierung von chemischen Bindungen durch die Farbe des Anregungslichts berichtet. Die Lichtfarbenregulation der Redoxkraft eines Photokatalysators ergänzt die Photoredoxkatalyse um einen neuen Selektivitätsparameter: Anstatt den Katalysator oder die Liganden auszutauschen, reicht der Wechsel der Anregungslichtfarbe aus, um die Selektivität einer chemischen Transformation zu ändern. Auf Grundlage dieses Prinzips gelingen die selektive Aktivierung von Aryl‐Halogen‐Bindungen für C‐H‐Arylierungen und die sequenzielle Umwandlung von funktionellen Gruppen mit unterschiedlichem Reduktionspotential durch verschiedene Lichtfarben zur Anregung desselben Photokatalysators.

Abstract Herein, we introduce catalysts that operate with chalcogen bonds. Compared to conventional hydrogen bonds, chalcogen bonds are similar in strength but more directional and hydrophobic, thus ideal for precision catalysis in apolar solvents. For the transfer hydrogenation of quinolines and imines, rate enhancements well beyond a factor of 1000 are obtained with chalcogen bonds. Better activities with deeper σ holes and wider bite angles, chloride inhibition and correlation with computed anion binding energies are consistent with operational chalcogen bonds. Comparable to classics, such as 2,2′‐bipyrroles or 2,2′‐bipyridines, dithieno[3,2‐b;2′,3′‐d]thiophenes (DTTs), particularly their diimides, but also wide‐angle cyclopentadithiazole‐4‐ones are identified as privileged motifs to stabilize transition states in the focal point of the σ holes on their two co‐facial endocyclic sulfur atoms.

Abstract In this work, for the first time, we constructed a novel multi‐nanozymes cooperative platform to mimic intracellular antioxidant enzyme‐based defense system. V2O5 nanowire served as a glutathione peroxidase (GPx) mimic while MnO2 nanoparticle was used to mimic superoxide dismutase (SOD) and catalase (CAT). Dopamine was used as a linker to achieve the assembling of the nanomaterials. The obtained V2O5@pDA@MnO2 nanocomposite could serve as one multi‐nanozyme model to mimic intracellular antioxidant enzyme‐based defense procedure in which, for example SOD, CAT, and GPx co‐participate. In addition, through assembling with dopamine, the hybrid nanocomposites provided synergistic antioxidative effect. Importantly, both in vitro and in vivo experiments demonstrated that our biocompatible system exhibited excellent intracellular reactive oxygen species (ROS) removal ability to protect cell components against oxidative stress, showing its potential application in inflammation therapy.

Abstract Thermoset polymers are known for their superior thermomechanical properties, but the chemical crosslinking typically leads to intractability. This is reflected in the great differences between thermoset and thermoplastic shape‐memory polymers; the former exhibit a robust shape memory but are not capable of redefining the permanent shape. Contrary to current knowledge, we reveal here that a classical thermoset shape‐memory polyurethane is readily capable of permanent reshaping (plasticity) after a topological network rearrangement that is induced by transcarbamoylation. By employing the Jianzhi technique (also known as kirigami), unexpected shape‐shifting versatility was observed for this otherwise classical material. As the essential carbamate moiety in polyurethanes is one of the most common polymer building units, we anticipate that our finding will have significant benefits beyond shape shifting.

Abstract A covalent triazine framework (CTF) with embedded polymeric sulfur and a high sulfur content of 62 wt % was synthesized under catalyst‐ and solvent‐free reaction conditions from 1,4‐dicyanobenzene and elemental sulfur. Our synthetic approach introduces a new way of preparing CTFs under environmentally benign conditions by the direct utilization of elemental sulfur. The homogeneous sulfur distribution is due to the in situ formation of the framework structure, and chemical sulfur impregnation within the micropores of CTF effectively suppresses the dissolution of polysulfides into the electrolyte. Furthermore, the triazine framework facilitates electron and ion transport, which leads to a high‐performance lithium–sulfur battery.

Abstract We report on a fast and simple method to produce highly stable isopropanol/water (4:1) suspensions of few‐layer antimonene by liquid‐phase exfoliation of antimony crystals in a process that is assisted by sonication but does not require the addition of any surfactant. This straightforward method generates dispersions of few‐layer antimonene suitable for on‐surface isolation. Analysis by atomic force microscopy, scanning transmission electron microscopy, and electron energy loss spectroscopy confirmed the formation of high‐quality few‐layer antimonene nanosheets with large lateral dimensions. These nanolayers are extremely stable under ambient conditions. Their Raman signals are strongly thickness‐dependent, which was rationalized by means of density functional theory calculations.

Abstract Die Forschung auf dem Gebiet der Redox‐Flow‐Batterie (RFB) erlebt momentan einen signifikanten Aufschwung, der durch den wachsenden Bedarf angetrieben wird, immer größere Elektrizitätsmengen aus erneuerbaren Quellen zwischenzuspeichern. RFBs sind vielversprechende Kandidaten, um in Kombination mit Photovoltaik‐ und Windkraftanlagen sogenannte “Smart Grids” (d. h. intelligente Stromnetze) aufzubauen. Um das Ziel eines “grünen”, sicheren und kostengünstigen Energiespeichers zu erreichen, wurde in den vergangen Jahren der Fokus von metallbasierten Materialien mehr und mehr auf organische Aktivmaterialien verlagert. In diesem Aufsatz wird eine Übersicht über verschiedene Flow‐Batterie‐Systeme gegeben. Dafür werden relevante Beiträge über die Geschichte dieser Systeme diskutiert und die Entwicklung innerhalb der letzten Jahre von klassischen, anorganischen über organisch/anorganische hin zu Redox‐Flow‐Batterien, welche innerhalb des Katholyten und Anolyten redoxaktive organische Materialien nutzen, aufgezeigt. Wir analysieren die verfügbaren Technologien in Bezug auf deren…

Abstract The design of high‐performance electrocatalysts for the alkaline hydrogen evolution reaction (HER) is highly desirable for the development of alkaline water electrolysis. Phase‐ and interface‐engineered platinum–nickel nanowires (Pt‐Ni NWs) are highly efficient electrocatalysts for alkaline HER. The phase and interface engineering is achieved by simply annealing the pristine Pt‐Ni NWs under a controlled atmosphere. Impressively, the newly generated nanomaterials exhibit superior activity for the alkaline HER, outperforming the pristine Pt‐Ni NWs and commercial Pt/C, and also represent the best alkaline HER catalysts to date. The enhanced HER activities are attributed to the superior phase and interface structures in the engineered Pt‐Ni NWs.

Abstract As an environmentally friendly approach to generate H2, electrocatalytic water splitting has attracted worldwide interest. However, its broad employment has been inhibited by costly catalysts and low energy conversion efficiency, mainly due to the sluggish anodic half reaction, the O2 evolution reaction (OER), whose product O2 is not of significant value. Herein, we report an efficient strategy to replace OER with a thermodynamically more favorable reaction, the oxidation of 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), catalyzed by 3D Ni2P nanoparticle arrays on nickel foam (Ni2P NPA/NF). HMF is one of the primary dehydration intermediates of raw biomass and FDCA is of many industrial applications. As a bifunctional electrocatalyst, Ni2P NPA/NF is not only active for HMF oxidation but also competent for H2 evolution. In fact, a two‐electrode electrolyzer employing Ni2P NPA/NF for simultaneous H2 and FDCA production required a voltage at least 200 mV smaller compared with pure water splitting to achieve the same current density, as well as exhibiting…

Abstract Luminescent materials consisting of boron clusters, such as carboranes, have attracted immense interest in recent years. In this study, luminescent organic–inorganic conjugated systems based on o‐carboranes directly bonded to electron‐donating and electron‐accepting π‐conjugated units were elaborated as novel optoelectronic materials. These o‐carborane derivatives simultaneously possessed aggregation‐induced emission (AIE) and thermally activated delayed fluorescence (TADF) capabilities, and showed strong yellow‐to‐red emissions with high photoluminescence quantum efficiencies of up to 97 % in their aggregated states or in solid neat films. Organic light‐emitting diodes utilizing these o‐carborane derivatives as a nondoped emission layer exhibited maximum external electroluminescence quantum efficiencies as high as 11 %, originating from TADF.

Abstract Au–Pd core–shell nanocrystals with tetrahexahedral (THH), cubic, and octahedral shapes and comparable sizes were synthesized. Similar‐sized Au and Pd cubes and octahedra were also prepared. These nanocrystals were used for the hydrogen‐evolution reaction (HER) from ammonia borane. Light irradiation can enhance the reaction rate for all the catalysts. In particular, Au–Pd THH exposing {730} facets showed the highest turnover frequency for hydrogen evolution under light with 3‐fold rate enhancement benefiting from lattice strain, modified surface electronic state, and a broader range of light absorption. Finite‐difference time‐domain (FDTD) simulations show a stronger electric field enhancement on Au–Pd core–shell THH than those on other Pd‐containing nanocrystals. Light‐assisted nitro reduction by ammonia borane on Au–Pd THH was also demonstrated. Au–Pd tetrahexahedra supported on activated carbon can act as a superior recyclable plasmonic photocatalyst for hydrogen evolution.

Abstract Compounds with stereogenic phosphorus atoms are frequently used as ligands for transition‐metal as well as organocatalysts. A direct catalytic enantioselective method for the synthesis of P‐chiral compounds from easily accessible diaryl phosphinamides is presented. The use of rhodium(III) complexes equipped with a suitable atropochiral cyclopentadienyl ligand is shown to enable an enantiodetermining C−H activation step. Upon trapping with alkynes, a broad variety of cyclic phosphinamides with a stereogenic phosphorus(V) atom are formed in high yields and enantioselectivities. Moreover, these can be reduced enantiospecifically to P‐chiral phosphorus(III) compounds.

Abstract Peptide‐tuned self‐assembly of functional components offers a strategy towards improved properties and unique functions of materials, but the requirement of many different functions and a lack of understanding of complex structures present a high barrier for applications. Herein, we report a photosensitive drug delivery system for photodynamic therapy (PDT) by a simple dipeptide‐ or amphiphilic amino‐acid‐tuned self‐assembly of photosensitizers (PSs). The assembled nanodrugs exhibit multiple favorable therapeutic features, including tunable size, high loading efficiency, and on‐demand drug release responding to pH, surfactant, and enzyme stimuli, as well as preferable cellular uptake and biodistribution. These features result in greatly enhanced PDT efficacy in vitro and in vivo, leading to almost complete tumor eradication in mice receiving a single drug dose and a single exposure to light.

Abstract While natural photosynthesis serves as the model system for efficient charge separation and decoupling of redox reactions, bio‐inspired artificial systems typically lack applicability owing to synthetic challenges and structural complexity. We present herein a simple and inexpensive system that, under solar irradiation, forms highly reductive radicals in the presence of an electron donor, with lifetimes exceeding the diurnal cycle. This radical species is formed within a cyanamide‐functionalized polymeric network of heptazine units and can give off its trapped electrons in the dark to yield H2, triggered by a co‐catalyst, thus enabling the temporal decoupling of the light and dark reactions of photocatalytic hydrogen production through the radical′s longevity. The system introduced here thus demonstrates a new approach for storing sunlight as long‐lived radicals, and provides the structural basis for designing photocatalysts with long‐lived photo‐induced states.

Abstract Aprotic lithium–oxygen (Li–O 2 ) batteries have attracted considerable attention in recent years owing to their outstanding theoretical energy density. A major challenge is their poor reversibility caused by degradation reactions, which mainly occur during battery charge and are still poorly understood. Herein, we show that singlet oxygen ( 1 Δ g ) is formed upon Li 2 O 2 oxidation at potentials above 3.5 V. Singlet oxygen was detected through a reaction with a spin trap to form a stable radical that was observed by time‐ and voltage‐resolved in operando EPR spectroscopy in a purpose‐built spectroelectrochemical cell. According to our estimate, a lower limit of approximately 0.5 % of the evolved oxygen is singlet oxygen. The occurrence of highly reactive singlet oxygen might be the long‐overlooked missing link in the understanding of the electrolyte degradation and carbon corrosion reactions that occur during the charging of Li–O 2 cells.

Abstract We report the first example of an AIEgen (DPP‐BO) with fluorescence–phosphorescence dual emission under mechanical stimulation. By carefully analyzing the crystal structure of DPP‐BO, the efficient intermolecular and intramolecular interactions should account for its unique mechanoluminescence (ML) properties, especially the abnormal phosphorescence, as further confirmed by controlled experiments and theoretical calculations for the presence of ISC transitions. These results provide important information for understanding the complex ML process, possibly opening up a new way to study the inherent mechanism of ML by broadening the application of AIEgens.

Abstract The environmental instability of single‐ or few‐layer black phosphorus (BP) has become a major hurdle for BP‐based devices. The degradation mechanism remains unclear and finding ways to protect BP from degradation is still highly challenging. Based on ab initio electronic structure calculations and molecular dynamics simulations, a three‐step picture on the ambient degradation of BP is provided: generation of superoxide under light, dissociation of the superoxide, and eventual breakdown under the action of water. The well‐matched band gap and band‐edge positions for the redox potential accelerates the degradation of thinner BP. Furthermore, it was found that the formation of P‐O‐P bonds can greatly stabilize the BP framework. A possible protection strategy using a fully oxidized BP layer as the native capping is thus proposed. Such a fully oxidization layer can resist corrosion from water and leave the BP underneath intact with simultaneous high hole mobility.

Abstract Die durch Bestrahlung mit sichtbarem Licht induzierte, Gold‐katalysierte intermolekulare Difunktionalisierung von Alkinen mit Aryldiazoniumsalzen in MeOH liefert verschiedene α‐Arylketone in moderaten bis guten Ausbeuten. Im Unterschied zu vorangegangenen Berichten zu auf Redoxzyklen beruhenden Gold‐katalysierten Reaktionen werden keine Oxidantien oder Photosensibilisatoren benötigt. Die Reaktion läuft unter milden Bedingungen ab und zeigt eine breite Toleranz gegenüber funktionellen Gruppen. Weitere Anwendungen dieses Protokolls demonstrieren die allgemeine Anwendbarkeit der Arylierung einer Vinylgold‐Zwischenstufe anstelle des normalerweise benutzten Protodemetallierungsschrittes. Dies ermöglicht den leichten Zugang zu höher funktionalisierten Produkten in Eintopfreaktionen. Mit einem P,N‐zweizähnigen Liganden wurde die stabile Arylgold(III)‐Spezies erhalten – der überhaupt erste experimentelle Nachweis für die allgemein postulierte direkte oxidative Addition von Aryldiazoniumsalzen an einen Pyridin‐Phosphin‐Gold(I)‐Komplex.

Abstract The first manganese‐catalyzed hydrogenation of esters to alcohols has been developed. The combination of Mn(CO)5Br with [HN(CH2CH2P(Et)2)2] leads to a mixture of cationic and neutral Mn PNP pincer complexes, which enable the reduction of various ester substrates, including aromatic and aliphatic esters as well as diesters and lactones. Notably, related pincer complexes with isopropyl or cyclohexyl substituents showed very low activity.

Abstract In coordination chemistry, catalytically active metal complexes in a zero‐ or low‐valent state often adopt four‐coordinate square‐planar or tetrahedral geometry. By applying this principle, we have developed a stable Pt1 single‐atom catalyst with a high Pt loading (close to 1 wt %) on phosphomolybdic acid(PMA)‐modified active carbon. This was achieved by anchoring Pt on the four‐fold hollow sites on PMA. Each Pt atom is stabilized by four oxygen atoms in a distorted square‐planar geometry, with Pt slightly protruding from the oxygen planar surface. Pt is positively charged, absorbs hydrogen easily, and exhibits excellent performance in the hydrogenation of nitrobenzene and cyclohexanone. It is likely that the system described here can be extended to a number of stable SACs with superior catalytic activities.

Abstract Glucose is a key energy supplier and nutrient for tumor growth. Herein, inspired by the glucose oxidase (GOx)‐assisted conversion of glucose into gluconic acid and toxic H2O2, a novel treatment paradigm of starving‐like therapy is developed for significant tumor‐killing effects, more effective than conventional starving therapy by only cutting off the energy supply. Furthermore, the generated acidic H2O2 can oxidize l‐Arginine (l‐Arg) into NO for enhanced gas therapy. By using hollow mesoporous organosilica nanoparticle (HMON) as a biocompatible/biodegradable nanocarrier for the co‐delivery of GOx and l‐Arg, a novel glucose‐responsive nanomedicine (l‐Arg‐HMON‐GOx) has been for the first time constructed for synergistic cancer starving‐like/gas therapy without the need of external excitation, which yields a remarkable H2O2–NO cooperative anticancer effect with minimal adverse effect.

Abstract Electron‐transfer (redox) thermochromism was successfully used for switching the conductance of semiconductors, by introducing a thermally active organic component into an inorganic semiconducting framework. A moisture‐resistant semiconductor {(MV)2[Pb7Br18]}n (MV2+=methyl viologen cation) has been prepared through an in situ synthetic method for MV2+. It features a rare 3D haloplumbate open framework and unprecedented electron‐transfer thermochromic behavior in haloplumbates. The electrical conductivity of this compound dropped significantly after coloration and restored after decoloration, which was satisfactorily explained by valence band XPS and theoretical data. This work not only offers a new approach to modify electrical properties of semiconductors without altering components or structures, but may lead to the development of over‐temperature color indicators, circuit overload protectors or photovoltaic materials.

Abstract The chemistry and physics of charged interfaces is regulated by the structure of the electrical double layer (EDL). Herein we quantify the average thickness of the Stern layer at the silica (SiO2) nanoparticle/aqueous electrolyte interface as a function of NaCl concentration following direct measurement of the nanoparticles’ surface potential by X‐ray photoelectron spectroscopy (XPS). We find the Stern layer compresses (becomes thinner) as the electrolyte concentration is increased. This finding provides a simple and intuitive picture of the EDL that explains the concurrent increase in surface charge density, but decrease in surface and zeta potentials, as the electrolyte concentration is increased.

Abstract Wet chemical synthesis of covalent III‐V colloidal quantum dots (CQDs) has been challenging because of uncontrolled surfaces and a poor understanding of surface–ligand interactions. We report a simple acid‐free approach to synthesize highly crystalline indium phosphide CQDs in the unique tetrahedral shape by using tris(dimethylamino) phosphine and indium trichloride as the phosphorus and indium precursors, dissolved in oleylamine. Our chemical analyses indicate that both the oleylamine and chloride ligands participate in the stabilization of tetrahedral‐shaped InP CQDs covered with cation‐rich (111) facets. Based on density functional theory calculations, we propose that fractional dangling electrons of the In‐rich (111) surface could be completely passivated by three halide and one primary amine ligands per the (2×2) surface unit, satisfying the 8‐electron rule. This halide–amine co‐passivation strategy will benefit the synthesis of stable III‐V CQDs with controlled surfaces.

Abstract This work demonstrates how photoredox‐mediated C(sp3)−H activation through radical translocation can be combined with asymmetric catalysis. Upon irradiation with visible light, α,β‐unsaturated N‐acylpyrazoles react with N‐alkoxyphthalimides in the presence of a rhodium‐based chiral Lewis acid catalyst and the photosensitizer fac‐[Ir(ppy)3] to provide a C−C bond‐formation product with high enantioselectivity (up to 97 % ee) and, where applicable, with some diastereoselectivity (3.0:1 d.r.). Mechanistically, the synthetic strategy exploits a radical translocation (1,5‐hydrogen transfer) from an oxygen‐centered to a carbon‐centered radical with a subsequent stereocontrolled radical alkene addition.

Abstract Aufgrund der einzigartigen Eigenschaften der Trifluormethoxygruppe finden Moleküle, die diesen Baustein enthalten, in verschiedenen Bereichen Anwendung, besonders in den Biowissenschaften. Obwohl also an dieser funktionellen Gruppe ein großes Interesse besteht, ist gegenwärtig nur eine geringe Anzahl an trifluormethoxylierten Molekülen präparativ zugänglich. In den letzten Jahren sind mehrere innovative und vielversprechende Strategien für die Synthese von trifluormethoxylierten Verbindungen beschrieben worden. In diesem Kurzaufsatz werden diese Methoden diskutiert, mit einem Fokus auf aktuelleren Fortschritten.

Abstract Metall‐organische Gerüste (MOFs) sind kristalline poröse Materialien, die aus bi‐ oder multipodalen organischen Linkern und Übergangsmetall‐Knoten aufgebaut sind. Manche MOFs zeigen hohe strukturelle Stabilität und flexible Zusammensetzungen. MOFs können aufgrund von Lichtabsorption durch die organische Komponente oder den Metalloxid‐Knoten photosensitiv sein. Die Photoanregung der Lichtabsorptionseinheiten generiert einen Ligand‐zu‐Metall‐Ladungstrennungszustand, der zu photokatalytischer Aktivität führen kann. In diesem Aufsatz diskutieren wir die Vorteile und Besonderheiten von MOFs im Zusammenhang mit der Photokatalyse. Wir besprechen geeignete Verfahren zur Bestimmung der photokatalytischen Aktivität von MOFs und zur Abscheidung von Kokatalysatoren. Insbesondere stellen wir Beispiele für die photokatalytische Aktivität von MOFs in der H2‐Entwicklung, der CO2‐Reduktion, der Photooxygierung und der Photoreduktion vor.

Abstract Two porous hydrogen‐bonded organic frameworks (HOFs) based on arene sulfonates and guanidinium ions are reported. As a result of the presence of ionic backbones appended with protonic source, the compounds exhibit ultra‐high proton conduction values (σ) 0.75× 10−2 S cm−1 and 1.8×10−2 S cm−1 under humidified conditions. Also, they have very low activation energy values and the highest proton conductivity at ambient conditions (low humidity and at moderate temperature) among porous crystalline materials, such as metal–organic frameworks (MOFs) and covalent organic frameworks (COFs). These values are not only comparable to the conventionally used proton exchange membranes, such as Nafion used in fuel cell technologies, but is also the highest value reported in organic‐based porous architectures. Notably, this report inaugurates the usage of crystalline hydrogen‐bonded porous organic frameworks as solid‐state proton conducting materials.

Abstract Ein benzanelliertes Doppel‐[7]Carbohelicen (D7H) wurde durch regioselektive Cyclodehydrierung einer Tetranaphthyl‐p‐Terphenyl‐Vorstufe hergestellt. Die verdrillten Konformere D7H‐1 und D7H‐2 wurden durch Kristallisation getrennt, und ihre doppelte Helicenstruktur mit sich überlappenden terminalen Benzolringen wurde röntgenographisch aufgeklärt. Die hohe Isomerisierungsbarriere (46.0 kcal mol−1) der Doppelhelicene wurde mit Dichtefunktionaltheorie berechnet, wodurch sich eine sehr hohe Konformationsstabilität von D7H ergab. Die physikochemischen Eigenschaften von D7H‐1 und D7H‐2 wurden durch UV/Vis‐Spektroskopie und Cyclovoltammetrie untersucht. Die Ergebnisse zeigen die konformationsabhängigen Unterschiede in der jeweiligen elektronischen Struktur. Die Racematspaltung von D7H‐1 erfolgte durch HPLC an chiraler Phase, und die enantiomerenreinen Konformere D7H‐1‐(P,P) und D7H‐1‐(M,M) konnten isoliert sowie durch CD‐Spektroskopie charakterisiert wurden.

Abstract Electrocatalytic CO 2 conversion into fuel is a prospective strategy for the sustainable energy production. However, still many parts of the catalyst such as low catalytic activity, selectivity, and stability are challenging. Herein, a hierarchical hexagonal Zn catalyst showed highly efficient and, more importantly, stable performance as an electrocatalyst for selectively producing CO. Moreover, we found that its high selectivity for CO is attributed to morphology. In electrochemical analysis, Zn (101) facet is favorable to CO formation whereas Zn (002) facet favors the H 2 evolution during CO 2 electrolysis. Indeed, DFT calculations showed that (101) facet lowers a reduction potential for CO 2 to CO by more effectively stabilizing a . COOH intermediate than (002) facet. This further suggests that tuning the crystal structure to control (101)/(002) facet ratio of Zn can be considered as a key design principle to achieve a desirable product from Zn catalyst.

Abstract The generation of ammonia from atmospheric nitrogen and water using sunlight is a preferable approach to obtaining ammonia as an energy carrier and potentially represents a new paradigm for achieving a low‐carbon and sustainable‐energy society. Herein, we report the selective conversion of dinitrogen into ammonia through plasmon‐induced charge separation by using a strontium titanate (SrTiO3) photoelectrode loaded with gold nanoparticles (Au‐NPs) and a zirconium/zirconium oxide (Zr/ZrOx) thin film. We observed the simultaneous stoichiometric production of ammonia and oxygen from nitrogen and water under visible‐light irradiation.

Abstract A symmetric sodium‐ion battery with an aqueous electrolyte is demonstrated; it utilizes the NASICON‐structured Na 3 MnTi(PO 4 ) 3 as both the anode and the cathode. The NASICON‐structured Na 3 MnTi(PO 4 ) 3 possesses two electrochemically active transition metals with the redox couples of Ti 4+ /Ti 3+ and Mn 3+ /Mn 2+ working on the anode and cathode sides, respectively. The symmetric cell based on this bipolar electrode material exhibits a well‐defined voltage plateau centered at about 1.4 V in an aqueous electrolyte with a stable cycle performance and superior rate capability. The advent of aqueous symmetric sodium‐ion battery with high safety and low cost may provide a solution for large‐scale stationary energy storage.

Abstract Der Ersatz teurer Edelmetalle durch in der Erde reichlich vorkommende Übergangsmetalle ist ein zentrales Thema in der Katalyse. Hier wird ein hochaktiver und selektiver, homogener, Mn‐basierter Hydrierkatalysator von C=O‐Bindungen vorgestellt. Der Katalysator verfügt über ein breites Substratspektrum und ist in der Lage, Aryl‐alkyl‐, Diaryl‐, Dialkyl‐ und Cycloalkylketone sowie Aldehyde zu hydrieren. Eine sehr gute Verträglichkeit mit funktionellen Gruppen, einschließlich der quantitativen und selektiven Hydrierung eines Ketons in Gegenwart eines nicht abgeschirmten Olefins, wird beobachtet. In der Mn‐Hydrierkatalyse ist die Kombination aus mehrzähnigem Liganden, Oxidationszustand des Metalls und richtigem Hilfsliganden wahrscheinlich entscheidend für eine hohe Aktivität. Diese Beobachtung unterstreicht einen Vorteil von Homogenkatalysatoren in der 3d‐Metallkatalyse. Für Koordinationsverbindungen ist eine Feinabstimmung einer komplexen Koordinationsumgebung leichter durchführbar als für Enzyme und/oder Heterogenkatalysatoren.

Abstract Effiziente und reversible Sauerstoffelektroden für die Sauerstoffreduktion (oxygen reduction reaction, ORR) sowie die Sauerstoffentwicklung (oxygen evolution reaction, OER) sind entscheidend für die Energieumwandlung beispielsweise in regenerativen Brennstoffzellen und Metall‐Luft‐Batterien. Die Realisierung solcher Elektroden wird im Wesentlichen durch unzureichende Aktivität und Stabilität der Elektrokatalysatoren sowohl bei der Wasserspaltung als auch bei der Sauerstoffreduktion erschwert. Wir berichten über hochaktive bifunktionale Elektrokatalysatoren für Sauerstoffelektroden. Die Katalysatoren bestehen aus Co@Co3O4‐Kern‐Schale‐Nanopartikeln, die durch Pyrolyse einer Cobalt‐haltigen Metall‐organischen Gerüstverbindung (MOF; ZIF‐67) in einer reduktiven H2‐Atmosphäre mit anschließender kontrollierter oxidativer Kalzinierung in CNT‐gekoppelte N‐dotierte Kohlenstoffpolyeder eingebettet wurden. Die Katalysatoren liefern eine reversible Gesamtüberspannung von 0.85 V in 0.1 m KOH‐Lösung und übertreffen damit Pt/C, IrO2 und RuO2, sodass sie zu den bislang besten nicht auf…

Abstract A dinuclear cobalt complex [Co 2 (OH)L 1 ](ClO 4 ) 3 ( 1 , L 1 =N[(CH 2 ) 2 NHCH 2 ( m ‐C 6 H 4 )CH 2 NH(CH 2 ) 2 ] 3 N) displays high selectivity and efficiency for the photocatalytic reduction of CO 2 to CO in CH 3 CN/H 2 O (v/v=4:1) under a 450 nm LED light irradiation, with a light intensity of 100 mW cm −2 . The selectivity reaches as high as 98 %, and the turnover numbers (TON) and turnover frequencies (TOF) reach as high as 16896 and 0.47 s −1 , respectively, with the calculated quantum yield of 0.04 %. Such high activity can be attributed to the synergistic catalysis effect between two Co II ions within 1 , which is strongly supported by the results of control experiments and DFT calculations.

Abstract The recent technological evolution of reaction monitoring techniques has not been paralleled by the development of modern kinetic analyses. The analyses currently used disregard part of the data acquired, thus requiring an increased number of experiments to obtain sufficient kinetic information for a given chemical reaction. Herein, we present a simple graphical analysis method that takes advantage of the data‐rich results provided by modern reaction monitoring tools. This analysis uses a variable normalization of the time scale to enable the visual comparison of entire concentration reaction profiles. As a result, the order in each component of the reaction, as well as kobs , is determined with just a few experiments using a simple and quick mathematical data treatment. This analysis facilitates the rapid extraction of relevant kinetic information and will be a valuable tool for the study of reaction mechanisms.

Abstract Chiral self‐assembly is a basic process in biological systems, where many chiral biomolecules such as amino acids and sugars play important roles. Achiral nucleobases usually covalently bond to saccharides and play a significant role in the formation of the double helix structure. However, it remains unclear how the achiral nucleobases can function in chiral self‐assembly without the sugar modification. Herein, we have clarified that purine nucleobases could trigger N‐(9‐fluorenylmethox‐ycarbonyl) (Fmoc)‐protected glutamic acid to self‐assemble into helical nanostructures. Moreover, the helical nanostructure could serve as a matrix and transfer the chirality to an achiral fluorescence probe, thioflavin T (ThT). Upon chirality transfer, the ThT showed not only supramolecular chirality but also circular polarized fluorescence (CPL). Without the nucleobase, the self‐assembly processes cannot happen, thus providing an example where achiral molecules played an essential role in the expression and transfer of the chirality.