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The article abstracts of various research papers that were recently been published in sister journals of the "Chemistry: A European Journal," including papers on synthesis of lactones, biosynthesis of lactic acid and homogeneous catalysis.

Fluorine‐containing polyanionic compounds have attracted much attention in the last few years as potential positive electrode materials for rechargeable batteries. With their formula AaMbXcO4Yd (A=Li, Na...; M=Ti, V, Mn, Fe, Co, Ni...; X=P or S, and Y=F, OH, O), they offer a very rich chemistry and their electrochemical properties can be tuned by carefully choosing the different constituting elements. However, synthesis approaches that allow these materials to be obtained at low temperature are almost nonexistent. In this paper, the use of a nonaqueous fluorolytic sol–gel approach is reported to synthesize a tavorite‐type LiFePO4F material and its electrochemical characterization was performed. The obtained material displays an electrochemical performance that positively compares with the literature with an excellent cycling stability (115 mA h−1 g−1 after 100 cycles at C/2 rate). A slight change in the synthesis parameters allowed Li2CoPO4F to be successfully obtained, demonstrating the versatility of the reported route, which can be adapted to synthesize other fluorine‐containing polyanionic compounds, which are of great interest for energy storage applications. [ABSTRACT FROM AUTHOR]

The synthesis of minerals should play a crucial role in the development of new and advanced materials. Since 2016, a renewal of interest to enlarge the mineral synthesis towards industrial requirements has been observed, especially thanks to three main recent papers. The innovative process exposed combines a continuous process with the use of supercritical water. In addition to curtail synthesis times, this process offers a control on the particle characteristics (size, crystallinity, structure, etc.) and a capacity to be easily transferable at an industrial scale. This innovative concept is demonstrated with the synthesis of three minerals which are the talc (a phyllomineral), the xonotlite and the tobermorite (two inominerals). This article proposes an overview of the possibilities to synthesize nanominerals in continuous processing for the development of advanced materials with promising industrial applications. [ABSTRACT FROM AUTHOR]

Growing demands of material science and, in particular, in the field of nonlinear optics (NLO) encourage us to look for stable highly polarizable molecules with excess diffuse electrons. An unusual class of compounds called electrides comply with these requirements. Many attempts have been made, yet only few electrides have been synthesized as solids and none of them as molecular species. In this paper, a new theoretically designed molecular species with electride characteristics is reported. The idea of this molecular electride comes from the formation of electride‐like features in the MgO crystal with defect F‐centers. The geometry of the investigated molecule can be described as a Mg4O4 cube with one oxygen atom removed. In Mg4O3, two 3s electrons are pushed out from the inner area of the molecule forming a diffuse electride multicentered bond. Our calculations show that this electride‐like cluster possesses a noticeably large first hyperpolarizability β=5733 au. At the same time, a complete cube Mg4O4 and Mg4O32+ without electride electron pair have much smaller β: 0 au and 741 au, respectively. This fact indicates the decisive role of the electride electron pair in NLO properties. Additionally, vertical detachment energies of isomers (VDE), excitation energies ΔE, polarizabilities α, and IR spectra were calculated. These properties, including β, are supposed to be observable experimentally and can serve as indirect evidence of the stable molecular electride formation. Elusive electride: Many attempts have been made, yet only few electrides have been synthesized as solids and none of them as molecular species. A theoretically designed molecular species with electride characteristics is reported based on the idea of formation of electride‐like features in MgO crystals with defect F‐centers. [ABSTRACT FROM AUTHOR]

The exceptionally mild conditions of a titanium(III)‐catalyzed cyclization reaction paired with a convenient acid/base extraction have enabled the straightforward synthesis, isolation, and direct N‐functionalization of amino heterocycles such as 3‐aminoindoles and ‐pyrroles. The unprotected heterocycles are ideal building blocks for the installation of aminated indoles and pyrroles into target molecules, but their sensitivity has previously impeded their synthesis by modern catalytic methods. This full paper presents the development and extended scope of the new cyclization methodology. The transformation of the products into fused bis‐indoles is also demonstrated along with the discovery of an unusual palladium‐catalyzed reductive biphenyl coupling reaction. The titanium(III)‐catalyzed cyclization has also been applied to the synthesis of substituted 3‐iminoindolines, which are of potential interest for applications in natural product synthesis and exhibit tunable blue‐to‐green fluorescence properties. Success at last! A titanium(III)‐catalyzed imine–nitrile cyclization gives rise to free aminoindoles, aminopyrroles, and iminoindolines that are ideal but fragile building blocks for the installation of such motifs into target molecules. Herein, the development, extended scope, and application of this reaction are described. Moreover, the fluorescence properties of the iminoindoline products are briefly reported. [ABSTRACT FROM AUTHOR]

Supramolecular structures of organic molecules on planar nanocarbon surfaces, such as highly oriented pyrolytic graphite (HOPG), have been extensively studied and the factors that control them are generally well‐established. In contrast, the properties of supramolecular structures on curved nanocarbon surfaces like carbon nanotubes remain challenging to predict and/or to understand. This paper reports an investigation into the first study of the supramolecular structures of 5,15‐bisdodecylporphyrin (C12P) on chiral, concentrated single‐walled carbon nanotubes (SWNTs; with right‐handed helix P‐ and left‐handed helix M‐) surfaces using STM. Furthermore, the study is the first of its kind to experimentally assign the absolute‐handedness chirality of SWNTs, as well as to understand their effect on the supramolecular structures of organic molecules on their surfaces. Interestingly, these SWNT enantiomers resulted in supramolecular structures of opposite chirality based on the handedness chirality. With molecular modelling, we predicted the absolute‐handedness chirality of SWNTs, before demonstrating this experimentally. By using the STM imaging technique, the single‐walled carbon nanotube (SWNT) absolute‐handedness of chirality has been experimentally investigated using supramolecular structures of porphyrin derivatives (C12P). Two opposite chiral supramolecular structures have been observed based on the SWNT enantiomers handedness of chirality (see figure). [ABSTRACT FROM AUTHOR]

The structural diversity of natural products and their derivatives have long contributed to the development of new drugs. However, the difficulty in obtaining compounds bearing skeletally novel structures has recently led to a decline of pharmaceutical research into natural products. This paper reports the construction of a meroterpenoid‐like library containing 25 compounds with diverse molecular scaffolds obtained from diversity‐enhanced extracts. This method constitutes an approach for increasing the chemical diversity of natural‐product‐like compounds by combining natural product chemistry and diversity‐oriented synthesis. Extensive pharmacological screening of the library revealed promising compounds for anti‐osteoporotic and anti‐lymphoma/leukemia drugs. This result indicates that the use of diversity‐enhanced extracts is an effective methodology for producing chemical libraries for the purpose of drug discovery. Extending diversity: A meroterpenoid‐like library containing 25 compounds with diverse molecular scaffolds was constructed from diversity‐enhanced extracts, which constitutes an approach for increasing the chemical diversity of natural‐product‐like compounds by combining natural product chemistry and diversity‐oriented synthesis (see figure). Extensive pharmacological screening of the library revealed promising compounds for anti‐osteoporotic and anti‐lymphoma/leukemia drugs. [ABSTRACT FROM AUTHOR]

This paper presents an investigation of anodic TiO2 nanotube arrays (TNAs), with a Co3O4/CuO coating, for lithium‐ion batteries (LIBs). The coated TNAs are investigated using various analytical techniques, with the results clearly suggesting that the molar ratio of Co3O4/CuO in the TiO2 nanotubes substantially influences its battery performance. In particular, a cobalt/copper molar ratio of 2:1 on the TNAs (Co2Cu1@TNAs) features the best LIBs anode performance, exhibiting high reversible capacity and enhanced cycling stability. Noticeably, Co2Cu1@TNAs achieve excellent rate capability even after quite a high current density of 20.0 A g−1 (≈25 C, where C corresponds to complete discharge in 1 h) and superior volumetric reversible capacity of ≈3330 mA h−1 cm−3. This value is approximately seven times higher than those of a graphite‐based anode. This outstanding performance is attributed to the synergistic effects of Co2Cu1@TNAs: 1) the structural advantage of TNAs, with their large amount of free space to accommodate the large volume expansion during Li+ insertion/extraction and 2) the optimized ratio of Co3O4 and CuO in the composite for improved capacity. In addition, no binder or conductive agent is used, which is partly responsible for the overall improved volumetric capacity and electrochemical performance. Binder‐free Co3O4/CuO@TiO2 composites exhibit superior battery performances, relying on the synergetic effects between Co3O4 and CuO. [ABSTRACT FROM AUTHOR]

Intravascular oxygen delivery holds great potential to treat numerous hypoxic conditions and emergencies, including pulmonary disorders, hypoxic tumors, hemorrhagic shock, stroke, cardiac arrest and so on. Tremendous effort has been made in the past to find material solutions for the development of intravenous oxygen carriers and have ranged from blood substitutes to microbubbles with limited success. This paper highlights previous and recent progress in perfluorocarbon‐emulsions and microbubbles as intravenous gas carriers, including concerns over their long‐term stability, in vivo safety profiles, and oxygen transport efficacy. Their use as potential resuscitative therapeutics for treating various types of cardiac arrest is also discussed. Injectable oxygen: In this concept article, different biomaterials strategies to incorporate oxygen gas as injectable resuscitative therapeutics are discussed and compared, including perfluorocarbon emulsions and microbubbles stabilized by lipids and degradable polymers. [ABSTRACT FROM AUTHOR]

The aqueous oxygen reduction reaction (ORR) has recently received increased attention due to its critical role in clean and sustainable energy‐generation technologies, such as proton exchange membranes (PEM) fuel cells, alkaline fuel cells and Zn–air batteries. The sluggish kinetics associated with ORR result from multistep electron‐transfer process. The slow kinetics are partially related to the O2 adsorption process onto the catalyst, which happens at the triple‐phase boundary (TPB) of the electrocatalyst–electrolyte–oxygen interface. Hence, tremendous efforts have been devoted to improving the intrinsic properties of electrocatalysts such as active sites, electrical conductivity and porosity. Engineering the electrocatalyst's interfacial properties is another critical issue in ORR, however less described in the literature. The surface of the catalyst provides the microenvironment for the triple boundary interface reaction, which directly influences its electrocatalytic activity and the kinetics. This Minireview is a summary of the existing literature on manipulating the interfacial surface of non‐precious metal catalysts at the triple point between the solid catalyst, the aqueous electrolyte and the O2 gas with the aim of improving the ORR efficiency. Various approaches towards improving the wettability and nanostructuring the catalyst surface to boost the activity of the surface‐active sites and provide improved stability are discussed. Promoting adsorption: The sluggish kinetics resulting from multistep electron transfer processes is the main concern in ORR. Promoting O2 adsorption, which happens on the triple‐phase boundary (TPB) of electrocatalyst–electrolyte–oxygen interface can overcome the slow kinetics. In this paper we review some of the existing surface engineering strategies in the literature aiming to manipulate the triple point boundary (TPB) to promote the aqueous ORR. [ABSTRACT FROM AUTHOR]

Borates are one of the most important classes of functional materials, and several hundreds of artificial borates have been synthesized. The substitution of oxygen by fluorine leads to manifold classes of borates. Fluorooxoborates (also known as fluoroborates), in which the F atoms covalently connect with the B atoms, show additional compositional and structural diversity compared to classic borates. Recently, owing to the large polarizability anisotropy, large HOMO–LUMO gaps, and high hyperpolarizability of the oxyfluoride BOxF4−x building blocks, fluorooxoborates have received unprecedented attention in the search for new ultraviolet (UV) and deep‐UV (DUV) nonlinear optical (NLO) materials. Specifically, some compounds have excellent NLO properties that are comparable or superior to KBe2BO3F2, which is the only usable crystal that generates coherent light below 200 nm through a direct second harmonic generation (SHG) process. This Minireview illustrates recent progress on the synthesis, crystal structures, structure‐properties relationships and applications of fluorooxoborates. This paper concludes by highlighting the outstanding opportunities offered by NLO fluorooxoborate crystals as an innovative avenue for DUV all solid‐state coherent light generation. In at the deep end: The deep ultraviolet nonlinear optical materials with excellent comprehensive performance are the key for the development of deep ultraviolet all solid‐state lasers. This Minireview focuses on the design strategies, synthetic approaches, crystal chemistry, and structure‐properties relationships of recent research highlight fluorooxoborates. [ABSTRACT FROM AUTHOR]

Corrole derivatives have been recently employed in many applications at the solid–liquid interface. Therefore, the structural arrangement of the molecular layers in direct contact with the liquid is of fundamental interest. We investigated in solution the deposition of molecular layers of the previously prepared water‐soluble phosphorus complex of a 2‐sulfonato‐10‐(4‐sulfonatophenyl)‐5,15‐dimesitylcorrole [see synthesis in our previous paper, M. Naitana et al. Chem. Eur. J. 2017, 23, 905–916]. The layer formation of P corroles onto the Au(111) surface was monitored by STM in situ, that is, with the substrate immersed in the solution. Marked differences in the morphology between the organic layer formed on the substrate and that deposited after solvent evaporation (drop casting) are reported. In particular, the coating of gold was more effective and stable in the presence of liquid. Preservation of functionality of the corrole molecules after adsorption was verified. This result validates the relevance of corrole layers at the solid–liquid interface to exploit the peculiar properties of these molecules in real‐world applications. Monitoring of layer formation of a phosphorus corrole onto the Au(111) surface was performed by STM in situ, that is, with the substrate immersed in the solution. Preservation of the functionality of corrole molecules after adsorption was verified. [ABSTRACT FROM AUTHOR]

In this paper, the synthesis, comprehensive characterization and biological and photocatalytic properties of two series of neutral IrIII biscyclometalated complexes of general formula [Ir(C^N)2(N^O)], where the N^O ligands are 2‐(benzimidazolyl)phenolate‐N,O (L1, series a) and 2‐(benzothiazolyl)phenolate‐N,O (L2, series b), and the C^N ligands are 2‐(phenyl)pyridinate or its derivatives, are described,. Complexes of types a and b exhibit dissimilar photophysical and biological properties. In vitro cytotoxicity tests conclusively prove that derivatives of series a are harmless in the dark against SW480 cancer cells (colon adenocarcinoma), but express enhanced cytotoxicity versus the same cells after stimulation with UV or blue light. In contrast, complexes of type b show a very high cytotoxic activity in the dark, but low photosensitizing ability. Thus, the ancillary N^O ligand is the main factor in terms of cytotoxic activity both in the dark and upon irradiation. However, the C^N ligands play a key role regarding cellular uptake. In particular, the complex of formula [Ir(dfppy)2(L1)] (dfppy=2‐(4,6‐difluorophenyl)pyridinate) [3 a] has been identified as both an efficient photosensitizer for 1O2 generation and a potential agent for photodynamic therapy. These capabilities are probably related to a combination of its notable cellular internalization, remarkable photostability, high photoluminescence quantum yield, and long triplet excited‐state lifetime. Both types of complexes exhibit notable catalytic activity in the photooxidation of thioanisole and S‐containing aminoacids with full selectivity. Phototherapy: Influence of the ancillary ligand on the PDT properties of IrIII complexes—two series of IrIII complexes with 2‐benzoazole‐phenolates are described, and their anticancer activity both in the dark and under irradiation are evaluated. [ABSTRACT FROM AUTHOR]

Engineering the properties of conjugated materials in the solid state is an unsolved, ongoing challenge important to fundamental understanding of how non‐covalent interactions dictate packing and key properties, as well as the development of technologies based in organic optoelectronics. The most common design paradigm of such materials divide them into a "main chain" with extended conjugation, the chemical structure of which determines optoelectronic properties, and "side chains" not conjugated to the backbone, which provide solubility when they are long alkyl chains. This paper describes comparisons between phenylene‐ethynylene molecules in which slight changes to the structure of "side chains"—swapping hydrogen and fluorine atomic position on an aromatic ring—results in unexpectedly large changes in the solid‐state optical properties. In a pair of anisyl‐terminated three‐ring phenylene‐ethynylenes, switching the side chain arenes of benzyl esters from 2,4,6‐trifluoro to 2,3,6‐trifluoro results in a shift in fluorescence emission spectra of over 100 nm, as well as the opposite direction of force‐induced shifting of emission. Through a combination X‐ray crystal structures, electronic structure calculations, and comparisons with other derivatives, we describe how the 2,4,6‐trifluorinated side chains yield cofacial fluoroarene‐arene stacking interactions that twist the PE backbone out of conjugation, while the 2,3,6‐trifluoro side chains do not stack, instead yielding more coplanar PE backbones that form intermolecular aggregates. Overall, this work demonstrates how slight modifications to parts of conjugated materials normally considered ancillary to optoelectronic properties can determine their solid‐state properties, epitomizing the challenge of rational design but at the same time offering opportunities for materials discovery and improved understanding of non‐covalent interactions. The optical properties of solid phenylene‐ethynylenes depend heavily upon the regiochemistry of fluorinated aromatic side chains not conjugated to the chromophore. In addition to a >100 nm difference of fluorescence, force‐induced shifting of emission switches direction between the two isomers. X‐ray crystal structures rationalize these effects. [ABSTRACT FROM AUTHOR]

Metal complexes constitute an important class of DNA binders. In particular, a few ruthenium polyazaaromatic complexes are attractive as "light switches" because of their strong luminescence enhancement upon DNA binding. In this paper, a comprehensive study on the binding modes of several mononuclear and binuclear ruthenium complexes to human telomeric sequences, made of repeats of the d(TTAGGG) fragment is reported. These DNA sequences form G‐quadruplexes (G4s) at the ends of chromosomes and constitute a relevant biomolecular target in cancer research. By combining spectroscopy experiments and molecular modelling simulations, several key properties are deciphered: the binding modes, the stabilization of G4 upon binding, and the selectivity of these complexes towards G4 versus double‐stranded DNA. These results are rationalized by assessing the possible deformation of G4 and the binding free energies of several binding modes via modelling approaches. Altogether, this comparative study provides fundamental insights into the molecular recognition properties and selectivity of Ru complexes towards this important class of DNA G4s. Ru ready to bind? A comprehensive study on the binding modes of several mononuclear and binuclear ruthenium complexes to human telomeric sequences is reported, providing fundamental insights into the molecular recognition properties and selectivity of Ru complexes towards this important class of DNA G4s. [ABSTRACT FROM AUTHOR]

For the last decades, the chemical reduction of Au3+ to Au0 has been widely employed to produce various gold nanostructures. In comparison with the fast reduction, the slow reduction is systematically investigated in this research to provide more insights to reveal intermediary process and further disclose the underlying mechanism for growing gold nanostructures by using a series of simple ligands with aldehyde groups as weak reducing agents. The different binding energies of ligands to Aun+ (n=3, 1 and 0) exhibit variable binding affinities in starting, intermediate, and final gold species. For example, formic acid has much stronger binding affinity to Au+ than Au3+, and thus Au+ intermediate is able to be stabilized/captured during slow reduction of Au3+. Upon the disproportionation of Au+ to Au0 and Au3+, formic acid has much stronger binding affinity to the newly formed Au0 than other ligands for the controlled formation of gold nanostructures. Meanwhile, the adsorption of ligands causes substantially decreased surface energies on different gold planes. There are much higher energies on {110} planes compared to the other two {111} and {100} planes with certain ratios in these energies, leading to morphological growth of gold nanosheets. In this paper, we experimentally demonstrate anisotropic growth of gold nanosheets by using various ligands with weak reducing and appropriate coordination capabilities, and further provide insights to understand their morphological growth mechanism behind. This synthetic strategy is successfully extended to prepare silver, palladium, and platinum nanoplates. Going for gold: A facile method has been developed to synthesize gold nanostructures and investigate their formation mechanism by using various ligands with weak reducing and appropriate coordination capabilities, providing insights to the underlying growth mechanism for the formation of intermediate Au+ during retarded reduction. The morphology of the anisotropic gold nanostructures is controlled by surface energies of ligand‐bound gold planes with certain energy ratios and binding affinities of ligands to Au0. [ABSTRACT FROM AUTHOR]

Photocatalysis is an efficient approach to degrade hydrogen sulfide (H2S) and titanium dioxide (TiO2) is commonly used as a catalyst for H2S degradation. However, the low separation rate of photoinduced carriers and low gas adsorption ability of TiO2 limit its H2S photocatalytic decomposition rate. In this paper, single‐crystalline TiO2 nanowires are assembled on one‐dimensional carbon nanofibers (CNFs) and a tunable metal–organic framework (MOF) coating is fabricated on the surface of the TiO2 nanowires using a versatile step‐by‐step self‐assembly strategy. The excellent photocatalytic properties of the resulting membrane originate from the ability of the CNFs to rapidly transport charge carriers and the high and regenerable H2S adsorption ability of the MOF. The photocatalytic mechanism of the as‐prepared material was also discussed. Therefore, this work provides a promising method to improve the photocatalytic performance of H2S degradation. Insane in the membrane: A carbon nanofiber/TiO2 nanowire/MIL‐100 (denoted as CTWM) membrane was prepared as a photocatalyst that allowed the simultaneous adsorption and catalysis of H2S. The MIL‐100 MOF coated on the surface of the TiO2 nanowires in the CTWM membrane enhanced its photocatalytic activity by increasing its H2S adsorption ability. In addition, the carbon nanofiber (CNF)‐supported material displayed rapid transport of charge carriers and favourable recycling characteristics. [ABSTRACT FROM AUTHOR]

Abstract: The accelerating research interest in graphene involving the use of Hummers method has generated non‐negligible amount of wastewater containing residual graphite as well as Mn2+. In this paper, we report the first example of using this wastewater as precursor to prepare Mn3O4/N‐doped graphite (NG) composites through a facile solvothermal process. The mass fraction of Mn3O4 in the composites was manipulated by adding various amounts of extra Mn2+. The conversion of Mn2+ to Mn3O4 nanoparticles and the N atoms doping were achieved by adding hydrazine hydrate and ammonia into the system. The as‐obtained Mn3O4/NG composites were well characterized by SEM, TEM, EDS, Raman, XPS, TGA, XRD and N2 adsorption–desorption experiments and showed excellent catalytic performances as well as stability in the degradation of a model organic pollutant methylene blue (MB). Theoretical simulation was also carried out to illustrate the structural features of the Mn3O4/NG composite. This work presents a novel idea of designing functional materials from waste precursors. [ABSTRACT FROM AUTHOR]

Abstract: A series of poorly soluble phenyl bis‐phosphinato bismuth(III) complexes [BiPh(OP(=O)R1R2)2] (R1=R2=Ph; R1=R2=p‐OMePh; R1=R2=m‐NO2Ph; R1=Ph, R2=H; R1=R2=Me) have been synthesised and characterised, and shown to have effective antibacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), methicillin‐resistant Staphylococcus aureus (MRSA) and vancomycin‐resistant Enterococcus (VRE). The bismuth complexes were incorporated into microfibrillated (nano‐) cellulose generating a bismuth‐cellulose composite as paper sheets. Antibacterial evaluation indicates that the Bi‐cellulose materials have analogous or greater activity against Gram positive bacteria when compared with commercial silver based additives: silver sulfadiazine loaded at 0.43 wt % into nanocellulose produces a 10 mm zone of inhibition on the surface of agar plates containing S. aureus whereas [BiPh(OP(=O)Ph2)2] loaded at 0.34 wt % produces an 18 mm zone of inhibition. These phenyl bis‐phosphinato bismuth(III) complexes show potential to be applied in materials in healthcare facilities, to inhibit the growth of bacteria capable of causing serious disease. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we designed a kind of aggregation‐induced emission (AIE) chiral fluorescence emitters (R/S‐BINOL‐CN enantiomers) in the aggregate state. Chiral emissive nematic liquid crystals (N*‐LCs) prepared by doping this kind of AIE‐active R/S‐BINOL‐CN enantiomers into a common achiral nematic liquid crystal (N‐LC, E7) can self‐assemble as the regularly planar Grandjean texture leading to high luminescence dissymmetry factor (glum) of aggregation‐induced circularly polarized luminescence (AI‐CPL) signal up to 0.41, which can be attributed to dipolar interactions from polar cyano groups and π–π interactions between binaphthyl moiety of the dopant R/S‐BINOL‐CN and biphenyl group of the host molecules (E7). [ABSTRACT FROM AUTHOR]

Abstract: 3‐Chloropropionyl chloride is a chemically versatile building block with applications in the field of adhesives, pharmaceuticals, herbicides and fungicides. Its current production entails problems concerning safety, prolonged reaction times and the use of excessive amounts of chlorinating reagents. We developed a continuous flow procedure for acid chloride formation from acrylic acid and a consecutive 1,4‐addition of hydrogen chloride generating 3‐chloropropionyl chloride, as presented in this paper. Up to 94 % conversion was reached in 25 minutes at mild temperatures and pressures. This continuous flow method offers a safer alternative and is highly efficient in terms of consumption of starting product and shorter residence time. Valorization of this building block is exemplified by the synthesis of beclamide, a compound with sedative and anticonvulsant properties. Over 80 % conversion towards this drug was achieved in 1 minute in a continuous flow setup. Further research is needed to telescope the synthesis of 3‐chloropropionyl chloride and subsequent beclamide formation without intermediate purification. [ABSTRACT FROM AUTHOR]

Abstract: The phase of nanocrystals has a key role in the modulation of catalytic properties. Uniform and well‐crystallized nickel phosphide nanocrystals with controlled phases (Ni5P4, Ni2P, and Ni12P5) and narrow size distributions are synthesized by a wet chemical method. The phases of the as‐synthesized nickel phosphide nanocrystals are controlled by the P/Ni precursor molar ratio, heating process, and time of reaction. Rarely reported nearly monodisperse 5.6 nm Ni5P4 nanocrystals are successfully synthesized and show superior hydrogen evolution reaction (HER) activity. Only a low overpotential of 103 mV is required to achieve the HER current of 10 mA cm−2 at a low catalyst loading of 0.12 mg cm−2. The high HER activity is attributed to the high quality of the as‐obtained Ni5P4 nanocrystals, which have the electronic effect from the Ni5P4 phase and also high surface area owing to the small particle size. A systematic study of the controlled synthesis of nickel phosphide nanocrystals is shown in this paper, and the HER catalytic activity is improved through the phase‐ and size‐controlled synthesis of nanocrystals. [ABSTRACT FROM AUTHOR]

Abstract: Diarylethene derivatives, the biological activity of which can be reversibly changed by irradiation with light of different wavelengths, have shown promise as scientific tools and as candidates for photocontrollable drugs. However, examples demonstrating efficient photocontrol of their biological activity are still relatively rare. This concept article discusses the possible reasons for this situation and presents a critical analysis of existing data and hypotheses in this field, in order to extract the design principles enabling the construction of efficient photocontrollable diarylethene‐based molecules. Papers addressing biologically relevant interactions between diarylethenes and biomolecules are analyzed; however, in most published cases, the efficiency of photocontrol in living systems remains to be demonstrated. We hope that this article will encourage further discussion of design principles, primarily among pharmacologists, synthetic and medicinal chemists. [ABSTRACT FROM AUTHOR]

Abstract: The reaction mechanism in an active site is of the utmost importance when trying to understand the role that an enzyme plays in biological processes. In a recently published paper [Theor. Chem. Acc. 2017, 136, 86], we formalised the Relative Energy Gradient (REG) method for automating an Interacting Quantum Atoms (IQA) analysis. Here, the REG method is utilised to determine the mechanism of peptide hydrolysis in the aspartic active site of the enzyme HIV‐1 Protease. Using the REG method along with the IQA approach we determine the mechanism of peptide hydrolysis without employing any arbitrary parameters and with remarkable ease (albeit at large computational cost: the system contains 133 atoms, which means that there are 17 689 individual IQA terms to be calculated). When REG and IQA work together it is possible to determine a reaction mechanism at atomistic resolution from data directly derived from quantum calculations, without arbitrary parameters. Moreover, the mechanism determined by this novel method gives concrete insight into how the active site residues catalyse peptide hydrolysis. [ABSTRACT FROM AUTHOR]

Abstract: Crystallography and quantum mechanics have always been tightly connected because reliable quantum mechanical models are needed to determine crystal structures. Due to this natural synergy, nowadays accurate distributions of electrons in space can be obtained from diffraction and scattering experiments. In the original definition of quantum crystallography (QCr) given by Massa, Karle and Huang, direct extraction of wavefunctions or density matrices from measured intensities of reflections or, conversely, ad hoc quantum mechanical calculations to enhance the accuracy of the crystallographic refinement are implicated. Nevertheless, many other active and emerging research areas involving quantum mechanics and scattering experiments are not covered by the original definition although they enable to observe and explain quantum phenomena as accurately and successfully as the original strategies. Therefore, we give an overview over current research that is related to a broader notion of QCr, and discuss options how QCr can evolve to become a complete and independent domain of natural sciences. The goal of this paper is to initiate discussions around QCr, but not to find a final definition of the field. [ABSTRACT FROM AUTHOR]

Abstract: Fe‐based electrocatalysts are elegant due to their better performance towards the oxygen reduction reaction. Nevertheless, they commonly contain different moieties, for example Fe‐Nx, Fe, Fe3C and N‐doped carbon, primarily the debatable assistance of these components towards ORR electrocatalysis, specifically for intermediate peroxide reduction reactions (PRR). In this paper, to explore the role of Fe‐Nx centres for PRR, a Fe‐N‐C electrocatalyst rooted in nitrogen‐doped carbon nanotubes with mesoporous structures was synthesized from a Fe/Zn‐dicyanoimidazolate framework. The use of dicyanoimidazole coordinated with iron can introduce the Fe‐Nx active sites as well as directional N‐doped carbon nanotubes, which is good for enhancing electronic conductance of the catalyst. The attained electrocatalyst shows tremendous enactment to ORR, being comparable to the activity of Pt/C in acidic and better in alkaline electrolytes. This study also reveals that Fe‐Nx active centres are responsible for less H2O2 production. Though the Fe‐Nx moieties and Fe3C/Fe particles encapsulated N‐doped carbon, both are active centres for ORR, however, Fe‐Nx sites are more active than others for peroxide reduction reaction. These perceptions suggest rational methodologies for more active and consequently further durable Fe‐N‐C catalysts. [ABSTRACT FROM AUTHOR]

Abstract: Ruthenium‐containing organometallic ionic liquids with the B(CN)4 anion were developed that generate microporous amorphous coordination polymers upon UV irradiation. UV light irradiation of [Ru(C5H5)(C6H5R)][B(CN)4] (R=butyl, ethyl, octyl) quantitatively generated a yellow powder of a coordination polymer with the formula [Ru(C5H5){B(CN)4}]n. In this reaction, the arene ligand is eliminated by UV irradiation and coordination polymer is formed by coordination of the cyano groups of the anion to the Ru ion. The photogenerated solids exhibited nitrogen absorption properties due to their microporous structure. This paper proposes a method to fabricate functional coordination polymers by photoirradiation of liquids. [ABSTRACT FROM AUTHOR]

Abstract: The luciferin/luciferase system of the firefly has been used in bioluminescent imaging to monitor biological processes. In order to enhance the efficiency and expand the application range, some efforts have been made to tune the light emission, especially the effort to obtain NIR light. However, those case‐by‐case studies have not together revealed the nature and mechanism of the color tuning. In this paper, we theoretically investigated the fluorescence of all kinds of typical oxyluciferin analogues. The present systematical modifications of both oxyluciferin and luciferase indicate that the essential factor affecting the emission color is the charge distribution (or the electric dipole moment) on the oxyluciferin, which impacts on the charge transfer to form the light emitter and, subsequently, influence the strength and wavelength of the emission light. More negative charge distributed on the “thiazolone moiety” of the oxyluciferin or its analogues leads to a redshift. Based on this conclusion, we theoretically designed optimal pairs of luciferin analogue and luciferase for emitting NIR light, which could inspire new synthetic procedures and practical applications. [ABSTRACT FROM AUTHOR]

Keywords: computational chemistry; hydrogen bonds; NBO; noncovalent interactions; QTAIM EN computational chemistry hydrogen bonds NBO noncovalent interactions QTAIM 1 1 1 04/17/23 20230413 NES 230413 B The main idea b of the paper "the acceptor rules and the donor chooses" is illustrated by representing the different binding modes as the available "vegetables" offered in the market, ruled by the hydrogen bond acceptors. Computational chemistry, hydrogen bonds, NBO, noncovalent interactions, QTAIM. [Extracted from the article]

A new fluorescent 1,3-diaminonaphthalimide conjugate of calix[4]arene receptor ( R) was synthesized and characterized. The receptor displays good selectivity towards trinitrophenol (TNP) over other explosive aromatic- and aliphatic-nitro compounds by exhibiting changes in its fluorescence emission. Receptor-coated cellulose paper strips are equally effective in terms of their selective detection of TNP over other aromatic- and aliphatic-nitro compounds. When used in solution or on cellulose paper strips, R can detect up to submicromolar concentration of TNP by exhibiting changes in its fluorescence emission and in its supramolecular structure upon interaction. Interestingly, the microscopy features of R, TNP, and { R+TNP} are quite distinct, indicating the interactions present between R and TNP, as studied by using AFM and TEM. Computationally modeled complexes of receptor with TNP and TNT show enormous difference in their interaction energies in the favor of TNP by showing the host-guest interaction of cation ⋅⋅⋅anion type in the presence of TNP but not TNT. This is because the receptor adopts an 'arms-open'-type structure in the case of the TNP complex, whereas it adopts an 'arms-closed'-type structure in the presence of TNT. Both the experimental and the computational studies reveal that the receptor selectively binds to TNP over TNT. Thus, R-coated Whatman No.1 filter paper strips provide easy, rapid, and economical detection of trace amounts of TNP both by visual and spectral measurement. [ABSTRACT FROM AUTHOR]

This paper presents a novel and unique feature of metallacarboranes, consisting of the linkage of this redox electro-active site to a stretchable polymer. This is based on polyTHF, a known and applied material. This hybrid material has the two ends functionalized: one with the aforementioned redox molecule and the other with a terminal OH group, both linked by a molecular spring. Moreover, the redox electro-active molecules can be synthesized with either cobalt (cobaltabisdicarbollide) or with iron (ferrabisdicarbollide), species whose respective E1/2 value differs by almost 1 V. The polymerization mechanism, based on an intermediate molecular crystal structure, is explained through an unexpected cyclization process of the dioxanate derivative of the metallacarboranes with an additional THF molecule. This is achieved in the absence of any metal or external electrophile. Surface functionalization of a Pt electrode by the electropolymerization of pyrrole doped with the pristine metallacarboranes and with the polyTHF hybrid materials is reported in this paper. [ABSTRACT FROM AUTHOR]

2019, which was proclaimed by the United Nations as the International Year of the Periodic Table, sees one hundred years since Alfred Werner, the first Swiss to receive a Nobel Prize in chemistry, passed away. The undoubted father of coordination chemistry, he is also well‐known for influencing many other fields of chemistry, including organic, inorganic, organometallic, bioinorganic, and stereochemistry. However, one of his more rare and unique contributions to chemistry, his 1905 version of the periodic system, to this day remains overlooked. The simple and elegant idea which he used to construct his periodic table has not been communicated to the English‐speaking world, because Alfred Werner published his only original paper on the periodic table in German. Werner's simple mathematical approach lead to overwhelming success with anticipating the future f‐block. He managed to predict almost perfectly the number of lanthanides, which was hotly debated at that time. Werner's genius vision was considerably ahead of its time. It was not until the 1940s and the discovery of actinide series when the idea of representing the elements as a 32‐column periodic table finally became justified. [ABSTRACT FROM AUTHOR]

Not really for I Chemistry - A European Journal i as the 2018 citations to papers other than Reviews and Articles account for a mere 0.1 % of all citations (still, think of the accuracy once more). In addition to the aforementioned issues, there is a problem that is less often discussed: The overrated accuracy notwithstanding, it is not at all clear what citation counts are actually measuring.[6] Since usually a journal is regarded better than another one with a lower Impact Factor, one would have to assume that the Impact Factor is a direct measure of quality. In the group of ChemPubSoc Europe journals we have observed several times that after rejection and resubmission to a different journal, strangely enough, a lot of references to the rejecting journal were replaced by references to the new journal. So this is my plea: Since the Impact Factor, and similar citation-based metrics, are likely to prevail and will continue to be used for evaluating not only journals but also researchers who publish in them, could you as an author please pay more attention to the citations, bearing in mind their implications. [Extracted from the article]

Abstract: Technological innovation enforces a revolutionized approach towards materials chemistry. In this paper a new methodology towards crystal engineering of polar materials for possible applications in linear or non‐linear optics (NLO), as well as ferroelectric, pyroelectric or piezoelectric crystals is presented. The necessity to fulfil several criteria concerning symmetry, electron properties of the building blocks, and also mechanical and optical stability was achieved by fusion of a pharmaceutical molecule and an NLO‐phore. Co‐crystals of 2‐amino‐5‐nitropyridine barbital, presented in this manuscript, show cutting‐edge optical performance. Large second harmonic generation (SHG) efficiency (40 times better than potassium dihydrogen phosphate, KDP), extreme birefringence (2.7 times higher than for calcite), simplicity in preparation, and optical and mechanical stability of the product proves that in fact a new generation of smart materials was obtained. [ABSTRACT FROM AUTHOR]

Abstract: There is significant interest in the rapid and efficient detection of amines, which are widely used in different industries and also serve as markers in many biological processes. This work reports that the coupling of a thiosemicarbazide binding motif and a naphthalimide‐based chromophore affords highly sensitive sensor molecules, which can indicate the presence of amines with a pronounced and readily visible color change. It was demonstrated that the binding mechanism involves a proton transfer from the thiosemicarbazide to the analyte. This process renders the mechanism highly sensitive and broadly exploitable. The potential usefulness of the sensor is demonstrated by fabricating an indicator paper, which allows for the detection of volatile amines at concentrations as low as ca. 10 ppm. [ABSTRACT FROM AUTHOR]

Abstract: Ionic porous organic polymers have attracted much attention due to their broad applications in catalysis, energy storage/conversion, proton conduction, etc. In this paper, an ionic porous organic polymer, CMP‐PM‐Me, was synthesized through post‐synthetic modification of a pyrimidine‐based conjugated microporous polymer, CMP‐PM, which was constructed by the palladium catalyzed Sonogashira reaction of 1,3,5‐triethynylbenzen and 2,5‐dibromopyrimidine. These two polymers are porous with Brunauer–Emmett–Teller surface areas of 416 and 241 m2 g−1 for CMP‐PM and CMP‐PM‐Me, respectively. Due to the cationic framework, CMP‐PM‐Me exhibits a much faster and more efficient adsorption performance to anionic dyes such as Congo red (CR) and methyl orange (MO) than that of CMP‐PM with a neutral framework. The uptakes for CR are 400.0 mg g−1 for CMP‐PM‐Me and 344.8 mg g−1 for CMP‐PM, respectively. Furthermore, CMP‐PM‐Me could quickly and drastically separate anionic dyes from the binary mixed solution of anionic and nonanionic dyes within a short time. This work not only enriches the family of ionic organic porous polymers and widens their synthetic utility, but also demonstrates their applications in the adsorption and separation of anionic dyes in water. [ABSTRACT FROM AUTHOR]

Abstract: Square‐planar rhodium(I) isocyanide complexes exhibit unique chemical reactivities such as the formation of Rh−Rh bonds and oxidative addition. This paper details the syntheses and properties of multifunctional ionic liquids containing RhI isocyanide complexes [Rh(nBuNC)4]X (X=Tf2N (=N(SO2CF3)2−), Nf2N (=N(SO2C4F9)2−), FSA (=N(SO2F)2−), CF3BF3−). Salts with Tf2N and Nf2N were liquids, whereas those with FSA and CF3BF3 were solids at room temperature. The salts exhibited thermochromism in the liquid state, changing from orange at high temperatures to blue‐purple at lower temperatures. This is based on the equilibrium between monomer, dimer, and other oligomers associated with Rh−Rh bond formation. The salts also exhibited fluorescence. Exposure of the Tf2N salt to methyl iodide vapor produced ionic liquid mixtures [Rh(nBuNC)4]x[Rh(nBuNC)4IMe](1−x)[Tf2N], concomitant with a color change from purple to red, orange, and yellow, extending the thermochromic color range. The reaction of the Tf2N salt and iodine produced mononuclear and polynuclear iodine adducts. Thus, these liquids exhibit thermochromism, fluorescence, vapochromism, chemical reactivities, and characteristic properties of ionic liquids. [ABSTRACT FROM AUTHOR]

Abstract: Toward ultra‐simple and field‐ready biosensors, we demonstrate a novel assay transducer mechanism based on interfacial property changes and capillary flow dynamics in antibody‐conjugated submicron particle suspensions. Differential capillary flow is tunable, allowing pathogen quantification as a function of flow rate through a paper‐based microfluidic device. Flow models based on interfacial and rheological properties indicate a significant relationship between the flow rate and the interfacial effects caused by target‐particle aggregation. This mechanism is demonstrated for assays of Escherichia coli K12 in water samples and Zika virus (ZIKV) in blood serum. These assays achieved very low limits of detection compared with other demonstrated methods (1 log CFU/mL E. coli and 20 pg/mL ZIKV whole virus) with an operating time of 30 s, showing promise for environmental and health monitoring. [ABSTRACT FROM AUTHOR]

Abstract: Phosgene and its substitutes, diphosgene and triphosgene, are highly toxic and widely used chemicals, so it is necessary to investigate their reactivity and develop facile, sensitive, and specific methods for detecting them. In this work, we have developed a new 1,8‐naphthalimide‐based fluorescent chemosensor, Phos‐2, which exhibits high sensitivity (detection limits: 0.2–0.7 n m), high selectivity to phosgene and its substitutes over nitric oxide (NO), various acyl chlorides, and nerve agent mimics in solutions. Based on investigation of the reaction kinetics of Phos‐2 with phosgene and its substitutes, a two‐step sensing mechanism was clarified. The second‐order rate constants (k2) of Phos‐2 reveal that the relative rate constants of phosgene, diphosgene, and triphosgene are 40:4:1. Moreover, a Phos‐2 test paper has been fabricated as a low‐cost, sensitive (≈5 ppm from observation by the naked eye or 0.1 ppm from a measurement), and efficient method for visual detection of a low concentration of phosgene in the gas phase. [ABSTRACT FROM AUTHOR]

Abstract: Detection of nitroaromatics at ultralow concentration is a major security concern in defense, forensics, and environmental science. To this end, a new triarylamine‐cored dendritic gelator (OGR) was synthesized, which produced thermoreversible, thixotropic, and fluorescent gels in n‐octanol. On gelation, both π–π* transitions and the emission peak of the gelator show redshifts with a 4.5‐fold increase of fluorescence intensity in the gel state indicating J‐aggregation. The nitrogen lone‐pair electrons of OGR make it a donor, and electron transfer occurs to acceptor nitroaromatics causing fluorescence quenching, which is further promoted due to its acidity. The Stern–Volmer rate constants measured for different nitroaromatics showed that it senses picric acid (PA) best. The contact‐mode technique with OGR‐treated paper strips can allow naked‐eye detection of PA under UV light down to 10−11  m concentration within 30 s. Reusability of the gel is achieved by treating OGR@PAx with NaOH solution. Impedance spectroscopic results indicated a decrease of both charge‐transport resistance and Warburg impedance on successive addition of PA. The limits of detection of PA determined from fluorescence and impedance measurements match well. Thus, the OGR gel is a reusable, low‐cost, specific sensor for PA by naked‐eye colorimetric, fluorescence, and impedance techniques. [ABSTRACT FROM AUTHOR]

Abstract: The search for molecular catalysts that efficiently activate or cleave the dinitrogen molecule is an active field of research. While many thermal dinitrogen cleavage catalysts are known, the photochemical activation of N2 has received considerably less attention. In this paper, the first computational study of the osmium dimer [Os(II,III)2(μ‐N2)(NH3)10]5+, which was shown to be capable of dinitrogen photocleavage, is presented. Despite its deceptively simple geometry, it has a complex electronic structure with a valence‐delocalized and electronically degenerate ground state. Using multiconfigurational methods, the electronic structure at the ground state geometry and along the dinitrogen cleavage coordinate was investigated. The results indicate that an unoccupied molecular orbital with σ‐bonding character between osmium and μ‐N atoms and σ‐antibonding dinitrogen character is most affected by N–N distance elongation. This implies that a lower barrier for thermal or photochemical N2 activation in linear M‐N‐N‐M complexes can be achieved by lowering the energetic separation between this unoccupied orbital and the HOMO, representing a specific target for future catalyst design. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis of stable open‐shell singlet diradicaloids is critical for their practical material application. So far, most reported examples are based on carbon‐centered radicals, which are intrinsically reactive, and there are very few examples of stable nitrogen‐centered diradicaloids. In this full paper, a series of soluble and stable bis(imino)rylenes up to octarylene were synthesized on the basis of newly developed dibromorylene intermediates. It was found that from hexarylene onward, these quinoidal rylenes showed open‐shell singlet ground states and could be thermally populated to paramagnetic triplet aminyl diradicals. They are stable due to efficient spin delocalization onto the rylene backbone as well as kinetic blocking of the aminyl sites by the bulky and electron‐deficient 2,4,6‐trichlorophenyl groups. They exhibited very different electronic structures, diradical character, excited‐state dynamics, one‐photon absorption, two‐photon absorption, and electrochemical properties from their respective aromatic rylene counterparts. These bis(imino)rylenes represent a rare class of stable, neutral, nitrogen‐centered aminyl diradicaloids. [ABSTRACT FROM AUTHOR]

Abstract: Fe3N and Fe3C nanocomposites have a wide range of applications thanks to their ceramic nature, magnetic properties, conductivity and catalytic activity, just to cite some. In many fields optimal performances are ensured by crystallinity, homogeneity and hierarchical organization. In the present paper, crystalline, magnetic and well‐defined nanofibres of iron nitride and iron carbide/carbon nanocomposite with tunable composition and size were prepared via electrospinning. The starting polymeric material was directly electrospun into fibres and then calcined, leading to a highly homogeneous final product of nanoparticles along the fibres (both outside and inside). A mechanistic study was undertaken and here discussed. The magnetic properties of the as‐prepared nanofibres were also studied. The as‐prepared final fibre mat composite material can serve as active catalyst, for example, in oxygen reduction reaction (where nanofibres outperformed mere nanoparticles), it can serve as functional support for classical catalytic processes or, thanks to its magnetic properties, can be applied in magnetic‐field assisted separation or as magneto‐active membranes. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the physicochemical properties of a rhenium (Re) complex [Re(bpy)(CO)3Cl] immobilized on a bipyridine‐periodic mesoporous organosilica (BPy‐PMO) acting as a solid support. The immobilized Re complex generated a metal‐to‐ligand charge transfer absorption band at 400 nm. This wavelength is longer than that exhibited by Re(bpy)(CO)3Cl in the polar solvent acetonitrile (371 nm) and is almost equal to that in nonpolar toluene (403 nm). The photocatalytic activity of this heterogeneous Re complex was lower than that of a homogeneous Re complex due to the reduced phosphorescence lifetime resulting from immobilization. However, the catalytic activity was enhanced by the co‐immobilization of the ruthenium (Ru) photosensitizer [Ru(bpy)3]2+ on the PMO pore surfaces. Quantum chemical calculations suggest that electron transfer between the Ru and Re complexes occurs through interactions between the molecular orbitals in the pore walls. These results should have applications to the design of efficient heterogeneous CO2 reduction photocatalysis systems. [ABSTRACT FROM AUTHOR]

Abstract: Mg(OH)2‐ and Mg(OH)2‐containing materials can provide excellent performance as supports for AuPd nanoparticles for the oxidation of glycerol in the absence of base, which is considered to be a result of additional basic sites on the surface of the support. However, its influence on the reaction solution is not generally discussed. In this paper, we examine the relationship between the basic Mg(OH)2 support and AuPd nanoparticles in detail using four types of catalyst. For these reactions, the physical interaction between Mg(OH)2 and AuPd was adjusted. It was found that the activity of the AuPd nanoparticles increased with the amount of Mg(OH)2 added under base‐free conditions, regardless of its interaction with the noble metals. In order to investigate how Mg(OH)2 affected the glycerol oxidation, detailed information about the performance of AuPd/Mg(OH)2, physically mixed (AuPd/C+Mg(OH)2) and (AuPd/C+NaHCO3) was obtained and compared. Furthermore, NaOH and Mg(OH)2 were added during the reaction using AuPd/C. All these results indicate that the distinctive and outstanding performance of Mg(OH)2 supported catalysts in base‐free condition is in fact directly related to its ability to affect the pH during the reaction and as such, assists with the initial activation of the primary alcohol, which is considered to be the rate determining step in the reaction. [ABSTRACT FROM AUTHOR]

Abstract: The large‐scale, low‐cost preparation of Pt‐based catalysts with high activity and durability for the methanol oxidation reaction is still challenging. The key to achieving this aim is finding suitable supporting materials. In this paper, N‐doped carbon nanofibrous networks are prepared by annealing a gel containing two inexpensive and ecofriendly precursors, that is, bacterial cellulose and urea, for the loading of Pt nanoparticles. An undoped analogue is also prepared for comparison. Meanwhile, the effect of the annealing temperature on the performance of the catalysts is evaluated. The results show that the N doping and higher annealing temperature can improve the electron conductivity of the catalyst and provide more active sites for the loading of ultrafine Pt nanoparticles with a narrow size distribution. The best catalyst exhibits a remarkably high electrocatalytic activity (627 mA mg−1), excellent poison tolerance, and high durability. This work demonstrates an ideal Pt supporting material for the methanol oxidation reaction. [ABSTRACT FROM AUTHOR]

Abstract: The ability of neutral transition‐metal hydrides to serve as a source of hydride ion H− or proton H+ is well appreciated. The hydride ligands possessing a partly negative charge are proton accepting sites, forming a dihydrogen bond, M−Hδ−⋅⋅⋅δ+HX (M=transition metal or metalloid). On the other hand, some metal hydrides are able to serve as a proton source and give hydrogen bond of M−Hδ+⋅⋅⋅X type (X=organic base). In this paper we analyse recent works on transition‐metal and boron hydrides showing i) how formation of an intermolecular complex between the reactants changes the Z−H (M−H and X−H) bond polarity and ii) what is the implication of such activation in the mechanisms of hydrides reactions. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are a class of porous organic-inorganic crystalline materials that have attracted much attention as H2 storage devices and catalytic supports. In this paper, the synthesis of highly-dispersed Ni nanoparticles (NPs) for the hydrogenation of olefins was achieved by employing Ni-MOF-74 as a precursor. Investigations of the structural transformation of Ni species derived from Ni-MOF-74 during heat treatment were conducted. The transformation was monitored in detail by a combination of XRD, in situ XAFS, and XPS measurements. Ni NPs prepared from Ni-MOF-74 were easily reduced by the generation of reducing gases accompanied by the decomposition of Ni- MOF-74 structures during heat treatment at over 300 °C under N2 flow. Ni-MOF-74-300 exhibited the highest activity for the hydrogenation of 1-octene due to efficient suppression of excess agglomerated Ni species during heat treatment. Moreover, Ni-MOF-74-300 showed not only high activity for the hydrogenation of olefins but also high size-selectivity because of the selective formation of Ni NPs covered by MOFs and the MOF-derived carbonaceous layer. [ABSTRACT FROM AUTHOR]

In the last decade, numerous studies of graphene doping by various metal and nonmetal elements have been done in order to obtain tailored properties, such as non-zero band gap, electrocatalytic activity, or controlled optical properties. From nonmetal elements, boron and nitrogen were the most studied dopants. Recently, it has been shown that in some cases the enhanced electrocatalytic activity of graphene and its derivatives can be attributed to metal impurities rather than to nonmetal elements. In this paper, we investigated the electrocatalytical properties of B/N codoped graphene with respect to the content of metallic impurities introduced by the synthesis procedures. For this purpose, a permanganate (Hummers) and a chlorate (Hofmann) route were used for the preparation of the starting graphene oxides (GO). The GO used for the synthesis of B/N codoped graphene had significantly difference compositions of oxygen functionalities as well as metallic impurities introduced by the different synthetic procedures. We performed a detailed structural and chemical analysis of the doped graphene samples to correlate their electrocatalytic activity with the concentration of incorporated boron and nitrogen as well as metallic impurities. [ABSTRACT FROM AUTHOR]

To reduce intrinsic defect density in perovskite films, various additives are often added into the precursor solution. In this paper, a novel solution, in which isopropanol (IPA) was added into the precursor solution, was developed for the preparation of normal planar perovskite solar cells (PSCs). A champion power conversion efficiency (PCE) of 19.70 % was achieved with this approach. By adding IPA into the precursor solution, CH3NH3PbI3 perovskite showed better crystallization and stability, indicating improved film quality. Because of the improved morphology of perovskite crystal, the PCE of PSCs increased. In addition, the unencapsulated PSCs retained high output for up to 40 days in air at room temperature, indicating the stability of PSCs. These results may provide a new avenue for manufacturing high efficiency and high stability PSCs. [ABSTRACT FROM AUTHOR]