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The article presents a study which examines the highly reversible lithium (Li)/dissolved polysulfide cell using a free-standing and self-weaving multi-walled carbon nanotube (MWCNT) paper as an electrode. The study investigates the MWCNT paper by a chemical vapor deposition process. The study reveals that a highly reversible Li/dissolved polysulfide cells were demonstrated as a host electrode.

A significant amount of attention has been given to the design and synthesis of co‐crystals by both industry and academia because of its potential to change a molecule's physicochemical properties. Yet, difficulties arise when searching for adequate combinations of molecules (or coformers) to form co‐crystals, hampering the efficient exploration of the target's solid‐state landscape. This paper reports on the application of a data‐driven co‐crystal prediction method based on two types of artificial neural network models and co‐crystal data present in the Cambridge Structural Database. The models accept pairs of coformers and predict whether a co‐crystal is likely to form. By combining the output of multiple models of both types, our approach shows to have excellent performance on the proposed co‐crystal training and validation sets, and has an estimated accuracy of 80 % for molecules for which previous co‐crystallization data is unavailable. [ABSTRACT FROM AUTHOR]

To boost the performance for various applications, a rational bottom‐up design on materials is necessary. The defect engineering on nanoparticle at the atomic level can efficiently tune the electronic behavior, which offers great opportunities in enhancing the catalytic performance. In this paper, we optimized the surface oxygen vacancy concentration and created the lattice distortion in rare‐earth‐based perovskite oxide through gradient replacement of the B site with valence alternated element. The dual defects make the electron spin state transit from low spin state to high spin state, thus decreasing the charge transport resistance. Furthermore, assembly the modified nanoparticle subunits into the micro‐sized hollow multishelled structures can provide porous shells, abundant interior space and effective contact, which enables an enhanced mass transfer and a shorter charge transport path. As a result, the systemic design in the electronic and nano‐micro structures for catalyst has brought an excellent oxygen evolution performance. [ABSTRACT FROM AUTHOR]

In common with other hindered structures containing two aromatic rings linked by a short tether, diarylamines may exhibit atropisomerism (chirality due to restricted rotation). Previous examples have principally been tertiary amines, especially those with cyclic scaffolds. Little is known of the structural requirement for atropisomerism in structurally simpler secondary and acyclic diarylamines. In this paper we describe a systematic study of a series of acyclic secondary diarylamines, and we quantify the degree of steric hindrance in the ortho positions that is required for atropisomerism to result. Through a detailed experimental and computational analysis, the role of each ortho‐substituent on the mechanism and rate of conformational interconversion is rationalised. We also present a simple predictive model for the design of configurationally stable secondary diarylamines. [ABSTRACT FROM AUTHOR]

The storage of solar energy in battery systems is pivotal for a sustainable society, which faces many challenges. Herein, a Zn–air battery is constructed with two cathodes of poly(1,4‐di(2‐thienyl))benzene (PDTB) and TiO2 grown on carbon papers to sandwich a Zn anode. The PDTB cathode is illuminated in a discharging process, in which photoelectrons are excited into the conduction band of PDTB to promote oxygen reduction reaction (ORR) and raise the output voltage. In a reverse process, holes in the valence band of the illuminated TiO2 cathode are driven for the oxygen evolution reaction (OER) by an applied voltage. A record‐high discharge voltage of 1.90 V and an unprecedented low charge voltage of 0.59 V are achieved in the photo‐involved Zn–air battery, regardless of the equilibrium voltage. This work offers an innovative pathway for photo‐energy utilization in rechargeable batteries. [ABSTRACT FROM AUTHOR]

Described in this paper are the synthesis and structure of novel and edge‐functionalized zigzag hydrocarbon belts. A stepwise "fjord‐stitching" strategy featuring repetitive intramolecular acylation reactions of a resorcin[4]arene derivative as the key steps afforded a biscarbonyl‐functionalized octahydrobelt[8]arene product. Facile ketone reduction with NaBH4 and nucleophilic addition with n‐butyllithium produced secondary and tertiary alcohol‐containing molecular belts, respectively. Selective oxidation reactions of biscarbonyl‐bearing octahydrobelt[8]arene with m‐CPBA and (PhSeO)2O furnished the corresponding lactone‐ and 1,4‐quinone‐embedded molecular belts. Depending on the functional groups on the edges, the acquired belt molecules adopt different shapes such as square prism, truncated cone, and elliptical cylinder. [ABSTRACT FROM AUTHOR]

In soft matter, thermal energy causes molecules to continuously translate and rotate, even in crowded environments, thereby impacting the spatial organization and function of most molecular assemblies, such as lipid membranes. Directly measuring the orientation and spatial organization of large collections (>3000 molecules μm−2) of single molecules with nanoscale resolution remains elusive. In this paper, we utilize SMOLM, single‐molecule orientation localization microscopy, to directly measure the orientation spectra (3D orientation plus "wobble") of lipophilic probes transiently bound to lipid membranes, revealing that Nile red's (NR) orientation spectra are extremely sensitive to membrane chemical composition. SMOLM images resolve nanodomains and enzyme‐induced compositional heterogeneity within membranes, where NR within liquid‐ordered vs. liquid‐disordered domains shows a ≈4° difference in polar angle and a ≈0.3π sr difference in wobble angle. As a new type of imaging spectroscopy, SMOLM exposes the organizational and functional dynamics of lipid‐lipid, lipid‐protein, and lipid‐dye interactions with single‐molecule, nanoscale resolution. [ABSTRACT FROM AUTHOR]

Metal–air batteries are considered one of the most promising next‐generation energy storage devices owing to their ultrahigh theoretical specific energy. However, sluggish cathode kinetics (O2 and CO2 reduction/evolution) result in large overpotentials and low round‐trip efficiencies which seriously hinder their practical applications. Utilizing light to drive slow cathode processes has increasingly becoming a promising solution to this issue. Considering the rapid development and emerging issues of this field, this Review summarizes the current understanding of light‐assisted metal–air batteries in terms of configurations and mechanisms, provides general design strategies and specific examples of photocathodes, systematically discusses the influence of light on batteries, and finally identifies existing gaps and future priorities for the development of practical light‐assisted metal–air batteries. [ABSTRACT FROM AUTHOR]

Polymer–drug conjugates are promising as strategies for drug delivery, because of their high drug loading capacity and low premature release profile. However, the preparation of these conjugates is often tedious. In this paper, we report an efficient method for polymer–drug conjugates using an ultrafast and reversible click reaction in a post‐polymerization functionalization strategy. The reaction is based on the rapid condensation of boronic acid functionalities with salicylhydroxamates. The polymer, bearing the latter functionality, has been designed such that the reaction with boronic acid bearing drugs induces an in situ self‐assembly of the conjugates to form well‐defined nanostructures. We show that this method is not only applicable for molecules with an intrinsic boronic acid group, but also for the other molecules that can be linked to aryl boronic acids through a self‐immolative linker. The linker has been designed to cause traceless release of the attached drug molecules, the efficiency of which has been demonstrated through intracellular delivery. [ABSTRACT FROM AUTHOR]

Huisgen's 1960 announcement of the concept of 1,3‐dipolar cycloadditions was published the year before Alder's study of the reaction of diazomethane and dimethylfulvene. The diazomethane reaction was studied again in 1970 by Houk et al. and shown to give a [6+4] adduct. Padwa's nitrile ylide cycloaddition to dimethylfulvene (1978) gave [6+4] and [4+2] adducts. We performed computational studies of these reactions with density functional theory (DFT) and show that they involve ambimodal [6+4]/[4+2] transition states that can lead to either type of cycloadduct from one transition state. We dedicate this paper to the extraordinary life and humanity of Rolf Huisgen, and to the undying influence of his discoveries on chemistry. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) show great promise for electrochemical CO2 reduction reaction (CRR), but the low density of active sites and the poor electrical conduction and mass transport of the single‐atom electrode greatly limit their performance. Herein, we prepared a nickel single‐atom electrode consisting of isolated, high‐density and low‐valent nickel(I) sites anchored on a self‐standing N‐doped carbon nanotube array with nickel–copper alloy encapsulation on a carbon‐fiber paper. The combination of single‐atom nickel(I) sites and self‐standing array structure gives rise to an excellent electrocatalytic CO2 reduction performance. The introduction of copper tunes the d‐band electron configuration and enhances the adsorption of hydrogen, which impedes the hydrogen evolution reaction. The single‐nickel‐atom electrode exhibits a specific current density of −32.87 mA cm−2 and turnover frequency of 1962 h−1 at a mild overpotential of 620 mV for CO formation with 97 % Faradic efficiency. [ABSTRACT FROM AUTHOR]

We reply to the comment by S. Pan and G. Frenking who challenged our interpretation of the Na−:→BH3 dative bond in the recently synthesized NaBH3− cluster. Our conclusion remains the same as that in our original paper (https://doi.org/10.1002/anie.201907089 and https://doi.org/10.1002/ange.201907089). This conclusion is additionally supported by the energetic pathways and NBO charges calculated at UCCSD and CASMP2(4,4) levels of theory. We also discussed the suitability of the Laplacian of electron density (QTAIM) and Adaptive Natural Density Partitioning (AdNDP) method for bond type assignment. It seems that AdNDP yields more sensible results. This discussion reveals that the complex realm of bonding is full of semantic inconsistencies, and we invite experimentalists and theoreticians to elaborate this topic and find solutions incorporating different views on the dative bond. [ABSTRACT FROM AUTHOR]

According to the well‐accepted mechanism, methyl‐coenzyme M reductase (MCR) involves Ni‐mediated thiolate‐to‐disulfide conversion that sustains its catalytic cycle of methane formation in the energy saving pathways of methanotrophic microbes. Model complexes that illustrate Ni‐ion mediated reversible thiolate/disulfide transformation are unknown. In this paper we report the synthesis, crystal structure, spectroscopic properties and redox interconversions of a set of NiII complexes comprising a tridentate N2S donor thiol and its analogous N4S2 donor disulfide ligands. These complexes demonstrate reversible NiII‐thiolate/NiII‐disulfide (both bound and unbound disulfide‐S to NiII) transformations via thiyl and disulfide monoradical anions that resemble a primary step of MCR's catalytic cycle. [ABSTRACT FROM AUTHOR]

SuFEx reactions, in which an S−F moiety reacts with a silyl‐protected phenol, have been developed as powerful click reactions. In the current paper we open up the potential of SuFEx reactions as enantioselective reactions, analyze the role of Si and outline the mechanism of this reaction. As a result, fast, high‐yielding, "Si‐free" and enantiospecific SuFEx reactions of sulfonimidoyl fluorides have been developed, and their mechanism shown, by both experimental and theoretical methods, to yield chiral products. [ABSTRACT FROM AUTHOR]

Vincent van Gogh used fugitive red lake pigments that have faded in some paintings. Mapping their distribution is key to understanding how his paintings have changed with time. While red lake pigments can be identified from microsamples, in situ identification and mapping remain challenging. This paper explores the ability of molecular fluorescence imaging spectroscopy to identify and, more importantly, map residual non‐degraded red lakes. The high sensitivity of this method enabled identification of the emission spectra of eosin (tetrabromine fluorescein) lake mixed with lead or zinc white at lower concentrations than elemental X‐ray fluorescence (XRF) spectroscopy used on account of bromine. The molecular fluorescence mapping of residual eosin and two carmine red lakes in van Gogh's The Olive Orchard is demonstrated and compared with XRF imaging spectroscopy. The red lakes are consistent with the composition of paint tubes known to have been used by van Gogh. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons with hexagons/pentagons or hexagons/heptagons have been intensively investigated in recent years, but those with simultaneous presence of hexagons, pentagons and heptagons remain rare. In this paper, we report dicyclohepta[ijkl,uvwx]rubicene (DHR), a non‐benzenoid isomer of dibenzo[bc,kl]coronene with two pentagons and two heptagons. We developed an efficient and scalable synthetic method for DHR by using Scholl reaction and dehydrogenation. Crystal structure of DHR shows that the benzenoid rings, two pentagons and two heptagons are coplanar. The bond lengths analysis and the ICSS(1)zz and LOL‐π calculations indicate that the incorporation of two formal azulene moieties has an effect on the conjugated structure. The π‐electrons of benzenoid and pentagon rings are more delocalized. Cyclic voltammetry studies indicate that DHR shows multiple oxidation and reduction potentials. Interestingly, DHR exhibits unusual S0 to S2 absorption and abnormal anti‐Kasha S2 to S0 emission. Moreover, crystals of DHR exhibit semiconducting behaviour with hole mobility up to 0.082 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

When computers plan multistep syntheses, they can rely either on expert knowledge or information machine‐extracted from large reaction repositories. Both approaches suffer from imperfect functions evaluating reaction choices: expert functions are heuristics based on chemical intuition, whereas machine learning (ML) relies on neural networks (NNs) that can make meaningful predictions only about popular reaction types. This paper shows that expert and ML approaches can be synergistic—specifically, when NNs are trained on literature data matched onto high‐quality, expert‐coded reaction rules, they achieve higher synthetic accuracy than either of the methods alone and, importantly, can also handle rare/specialized reaction types. [ABSTRACT FROM AUTHOR]

A new strategy for the synthesis of a covalent triazine framework (CTF‐1) was introduced based on the cyclotrimerization reaction of 1,4‐dicyanobenzene using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) under ionothermal conditions. LiTFSI not only served as a catalyst, but also facilitated the in situ generation and homogeneous distribution of LiF particles across the framework. The hierarchical structure resulting upon integration of CTF‐LiF onto an airlaid‐paper (AP) offered unique features for lithium metal anodes, such as lithiophilicity from CTF, interface stabilization from LiF, and sufficient lithium storage space from AP. Based on this synergistic effect, the AP‐CTF‐LiF anode exhibited stable cycling performance even at a current density of 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Water electrolysis is one of the most promising methods to produce H2 and O2 as high potential fuels. Comparing the two half‐reactions, the oxygen evolution reaction (OER) is the more difficult to be optimized and still relies on expensive noble metal‐based catalysts such as Ru or Ir. In this paper, we prepared nanoparticles of HfN and Hf2ON2 and tested them for the OER for the first time. The HfN sample, in particular, showed the highest activity, requiring an overpotential of only 358 mV at 10 mA cm−2 in Fe‐free electrolyte and, above all, exhibiting long‐term stability. This result places this system amongst one of the most promising catalysts for OER tested to date, in terms of sustainability, activity and stability. The prepared nanoparticles are small (less than 15 nm in diameter), well‐defined in shape and crystalline, and were characterised before and after electrochemical testing also via electron microscopy (EM), powder X‐ray diffraction (PXRD) and X‐ray photoelectron spectroscopy (XPS). [ABSTRACT FROM AUTHOR]

Although instrumental for optimizing their pharmacological activity, a molecular understanding of the preferential interactions given by volatile anesthetics is quite poor. This paper confirms the ability of halothane to work as a hydrogen‐bond (HB) donor and gives the first experimental proof that halothane also works as a halogen‐bond (HaB) donor in the solid state and in solution. A halothane/hexamethylphosphortriamide co‐crystal is described and its single‐crystal X‐ray structure shows short HaBs between bromine, or chlorine, and the phosphoryl oxygen. New UV/Vis absorption bands appear upon addition of diazabicyclooctane and tetra(n‐butyl)ammonium iodide to halothane solutions, indicating that nitrogen atoms and anions may mediate the HaB‐driven binding processes involving halothane as well. The ability of halothane to work as a bidentate/tridentate tecton by acting as a HaB and HB donor gives an atomic rationale for the eudismic ratio shown by this agent. [ABSTRACT FROM AUTHOR]

Neutral organic super electron donors (SEDs) display impressive reducing power but, until now, it has not been possible to use them catalytically in radical chain reactions. This is because, following electron transfer, these donors form persistent radical cations that trap substrate‐derived radicals. This paper unlocks a conceptually new approach to super electron donors that overcomes this issue, leading to the first catalytic neutral organic super electron donor. [ABSTRACT FROM AUTHOR]

The nature of the processes at the origin of life that selected specific classes of molecules for broad incorporation into cells is controversial. Among those classes selected were polyisoprenoids and their derivatives. This paper tests the hypothesis that polyisoprenoids were early contributors to membranes in part because they (or their derivatives) could facilitate charge transport by quantum tunneling. It measures charge transport across self‐assembled monolayers (SAMs) of carboxyl‐terminated monoterpenoids (O2C(C9HX)) and alkanoates (O2C(C7HX)) with different degrees of unsaturation, supported on silver (AgTS) bottom electrodes, with Ga2O3/EGaIn top electrodes. Measurements of current density of SAMs of linear length‐matched hydrocarbons—both saturated and unsaturated—show that completely unsaturated molecules transport charge faster than those that are completely saturated by approximately a factor of ten. This increase in relative rates of charge transport correlates with the number of carbon–carbon double bonds, but not with the extent of conjugation. These results suggest that polyisoprenoids—even fully unsaturated—are not sufficiently good tunneling conductors for their conductivity to have favored them as building blocks in the prebiotic world. [ABSTRACT FROM AUTHOR]

The retraction has been agreed upon following an investigation by an Investigation Committee (IC) of the Lawrence Berkeley National Laboratory (LBNL). The above article, published online in I Angewandte Chemie International Edition i on 11 March 2016 in Wiley Online Library (wileyonlinelibrary.com, DOI: 10.1002/anie.201510712), has been retracted by agreement between Lawrence Berkeley National Laboratory, the journal's Executive Committee, and Wiley-VCH GmbH, Weinheim. [Extracted from the article]

Behind the Science In my group's first paper (Chem. Eur. J. 2019) we reported an unusual butterfly-shaped dimeric dicopper hydride complex. " I The most important quality of a mentor is that they help you achieve your goals even though it might sometimes disadvantage them. We hypothesized that preventing dimerization would give a more accessible dicopper hydride and enable catalytic hydride insertion reactions. [Extracted from the article]

In this paper we report on the influence of light and oxygen on the stability of CH3NH3PbI3 perovskite-based photoactive layers. When exposed to both light and dry air the mp-Al2O3/CH3NH3PbI3 photoactive layers rapidly decompose yielding methylamine, PbI2, and I2 as products. We show that this degradation is initiated by the reaction of superoxide (O2-) with the methylammonium moiety of the perovskite absorber. Fluorescent molecular probe studies indicate that the O2- species is generated by the reaction of photoexcited electrons in the perovskite and molecular oxygen. We show that the yield of O2- generation is significantly reduced when the mp-Al2O3 film is replaced with an mp-TiO2 electron extraction and transport layer. The present findings suggest that replacing the methylammonium component in CH3NH3PbI3 to a species without acid protons could improve tolerance to oxygen and enhance stability. [ABSTRACT FROM AUTHOR]

Shuke Wu, a Professor of Biotechnology at Huazhong Agricultural University in Wuhan, China, has published an article titled "Production of Biobased Ethylbenzene by Cascade Biocatalysis with an Engineered Photodecarboxylase" in Angewandte Chemie International Edition. Wu's research focuses on biocatalysis, enzyme engineering, directed evolution, and synthetic biology. Wu's favorite example of chemistry in everyday life is how evolution shapes our world and human society. Wu believes that young professors and group leaders are not prepared for the administrative and teaching tasks that come with their positions. Wu's biggest motivation is making his scientific designs come true and helping his students and co-workers succeed. Wu's motto is "Just do it," and he celebrates success by having a big meal with his students and co-workers. Wu's favorite saying is "It doesn't matter if a cat is black or white, as long as it catches mice," which he applies to his research and his approach to working with students and co-workers. The idea for Wu's research was rooted in a previous paper he co-authored during his PhD studies, and it was made possible with the support of the Humboldt fellowship. [Extracted from the article]

“… To what extent is reproducibility a significant issue in chemical research? How can problems involving irreproducibility be minimized? … Researchers should be aware of the dangers of unconscious investigator bias, all papers should provide adequate experimental detail, and Reviewers have a responsibility to carefully examine papers for adequacy of experimental detail and support for the conclusions …” Read more in the Editorial by Robert G. Bergman and Rick L. Danheiser. [ABSTRACT FROM AUTHOR]

Despite the growth of research in universities on point-of-care (POC) diagnostics for global health, most devices never leave the laboratory. The processes that move diagnostic technology from the laboratory to the field--the processes intended to evaluate operation and performance under realistic conditions--are more complicated than they might seem. Two case studies illustrate this process: the development of a paper-based device to measure liver function, and the development of a device to identify sickle cell disease based on aqueous multiphase systems (AMPS) and differences in the densities of normal and sickled cells. Details of developing these devices provide strategies for forming partnerships, prototyping devices, designing studies, and evaluating POC diagnostics. Technical and procedural lessons drawn from these experiences may be useful to those designing diagnostic tests for developing countries, and more generally, technologies for use in resource-limited environments. [ABSTRACT FROM AUTHOR]

Colloidal barium-doped TiO2 nanocrystals have been developed that enable the highly reversible light-responsive color switching of redox dyes with excellent cycling performance and high switching rates. Oxygen vacancies resulting from the Ba doping serve as effective sacrificial electron donors (SEDs) to scavenge the holes photogenerated in TiO2 nanocrystals under UV irradiation and subsequently promote the reduction of methylene blue to its colorless leuco form. Effective color switching can therefore be realized without relying on external SEDs, thus greatly increasing the number of switching cycles. Ba doping can also accelerate the recoloration under visible-light irradiation by shifting the absorption edge of TiO2 nanocrystals to a shorter wavelength. Such a system can be further casted into a solid film to produce a rewritable paper on which letters and patters can be repeatedly printed using UV light and then erased by heating; this process can be repeated for many cycles and does not require additional inks. [ABSTRACT FROM AUTHOR]

Molecular weight distribution of polymers, termed dispersity (Đ), is a fundamental parameter for determining polymer material properties. This paper reports a novel approach for controlling Đ by exploiting a temperature‐selective radical generation in organocatalyzed living radical polymerization. The polymers with tailored Đ were synthesized in a batch system without the assistance of an external pump. A unique aspect of this approach is that Đ was tuneable from 1.11 to 1.50 in any segment in diblock, triblock, and multiblock copolymers and in any form of star and brush polymer without segmental or topological restriction. This approach is amenable to various monomers and free from metals and thus attractive for applications. The approach also generated polymer brushes on surfaces with tailored Đ. An interesting finding was that the polymer brushes exhibited unique interaction with external molecules, depending on the Đ value. Brush up: A novel approach for modulating polymer dispersity was developed. It is based on temperature‐selective organocatalyzed living radical polymerization and enabled dispersity modulation in any segment in linear and branched block copolymers as well as polymer brushes. A dispersity‐dependent size‐exclusion effect to external molecules was observed for the polymer brushes. [ABSTRACT FROM AUTHOR]

The Markovnikov rule, known to every student of organic chemistry, was formulated 150 years ago, in 1869. During its long history (almost as long as the history of organic chemistry itself), attitudes towards this famous statement of chemical reactivity have evolved from indifference up to the 1930s, through common acceptance as a useful educational paradigm with marginal use in research up to the 1990s, to its vigorous relaunch as an important designation of regioselectivity in the last few decades. The unexpected new popularity of the classical rule is accounted for by the rapid expansion in catalytic addition reactions and their critical importance as highly effective atom‐economical, regioselective methods in modern organic synthesis. A historical outline of the life and achievements of Vladimir Markovnikov is included to reveal the very wide scope of his interests as well as his prophetic predictions on structure, reactivity, selectivity, stereochemistry, and other key issues of organic chemistry. As a general rule: During its 150 year long history the Markovnikov rule, formulated by Vladimir Markovnikov, has undergone a rather incredible evolution. After starting as an empirical rule describing a particular organic reaction, it has become an important designation of regioselectivity that is applicable to a huge range of important organic transformations. [ABSTRACT FROM AUTHOR]

The production of CH3OH from the photocatalytic CO2 reduction reaction (PCRR) presents a promising route for the clean utilization of renewable resources, but charge recombination, an unsatisfying stability and a poor selectivity limit its practical application. In this paper, we present the design and fabrication of 0D/2D materials with polymeric C3N4 nanosheets and CdSe quantum dots (QDs) to enhance the separation and reduce the diffusion length of charge carriers. The rapid outflow of carriers also restrains self‐corrosion and consequently enhances the stability. Furthermore, based on quantum confinement effects of the QDs, the energy of the electrons could be adjusted to a level that inhibits the hydrogen evolution reaction (HER, the main competitive reaction to PCRR) and improves the selectivity and activity for CH3OH production from the PCRR. The band structures of photocatalysts with various CdSe particle sizes were also investigated quantitatively to establish the relationship between the band energy and the photocatalytic performance. Reduced to the max: A strategy for selective photocatalytic CO2 reduction in aqueous solution based on the adjustment of the reduction potential of electrons in CdSe quantum dots is presented. The approach also inhibits the competitive hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

Formation of radical–radical cocrystals is an important step towards the design of organic ferrimagnets. We describe a simple approach to generate radical–radical cocrystals through the identification and implementation of well‐defined supramolecular synthons which favor cocrystallization over phase separation. In the current paper we implement the structure‐directing interactions of the E−E bond (E=S, Se) of dithiadiazolyl (DTDA) and diselenadiazolyl (DSDA) radicals to form close contacts to electronegative groups. This is exemplified through the preparation and structural characterization of three sets of radical cocrystals; the 2:2 cocrystal [PhCNSSN]2[MBDTA]2 (4) [MBDTA=methyl benzodithiazolyl] and the 2:1 cocrystals [C6F5CNEEN]2[TEMPO] (E=S, 5; E=Se, 6). In 4 the two types of radical are linked via bifurcated inter‐dimer δ+S⋅⋅⋅Nδ− interactions whereas 5 and 6 exhibit a set of five‐centre δ+E⋅⋅⋅Oδ− contacts (E=S, Se). SOMO wrestling: Cocrystallization of radicals requires different open‐shell molecules to interact with each other rather than themselves. This process can be driven by careful selection of favorable electrostatic interactions between molecules. [ABSTRACT FROM AUTHOR]

Abstract: Benzylisoquinoline alkaloids (BIAs) are a structurally diverse family of plant secondary metabolites, which have been exploited to develop analgesics, antibiotics, antitumor agents, and other therapeutic agents. Biosynthesis of BIAs proceeds via a common pathway from tyrosine to (S)‐reticulene at which point the pathway diverges. Coclaurine N‐methyltransferase (CNMT) is a key enzyme in the pathway to (S)‐reticulene, installing the N‐methyl substituent that is essential for the bioactivity of many BIAs. In this paper, we describe the first crystal structure of CNMT which, along with mutagenesis studies, defines the enzymes active site architecture. The specificity of CNMT was also explored with a range of natural and synthetic substrates as well as co‐factor analogues. Knowledge from this study could be used to generate improved CNMT variants required to produce BIAs or synthetic derivatives. [ABSTRACT FROM AUTHOR]

Abstract: Small‐molecule‐based fluorescent probes have become important tools in biology for sensing and imaging applications. However, the biological applications of many of the fluorescent molecules are hampered by low cellular uptake and high toxicity. In this paper, we show for the first time that the introduction of halogen atoms enhances the cellular uptake of fluorescent molecules and the nature of halogen atoms plays a crucial role in the plasma membrane transport in mammalian cells. The remarkably higher uptake of iodinated compounds compared to that of their chloro or bromo analogues suggests that the strong halogen bonding ability of iodine atoms may play an important role in the membrane transport. This study provides a novel strategy for the transport of fluorescent molecules across the plasma membrane in living cells. [ABSTRACT FROM AUTHOR]

Abstract: Carbon dioxide (CO2) reduction in aqueous solutions is an attractive strategy for carbon capture and utilization. Cuprous oxide (Cu2O) is a promising catalyst for CO2 reduction as it can convert CO2 into valuable hydrocarbons and suppress the side hydrogen evolution reaction (HER). However, the nature of the active sites in Cu2O remains under debate because of the complex surface structure of Cu2O under reducing conditions, leading to limited guidance in designing improved Cu2O catalysts. This paper describes the functionality of surface‐bonded hydroxy groups on partially reduced Cu2O(111) for the CO2 reduction reaction (CO2RR) by combined density functional theory (DFT) calculations and experimental studies. We find that the surface hydroxy groups play a crucial role in the CO2RR and HER, and a moderate coverage of hydroxy groups is optimal for promotion of the CO2RR and suppression of the HER simultaneously. Electronic structure analysis indicates that the charge transfer from hydroxy groups to coordination‐unsaturated Cu (CuCUS) sites stabilizes surface‐adsorbed COOH*, which is a key intermediate during the CO2RR. Moreover, the CO2RR was evaluated over Cu2O octahedral catalysts with {111} facets and different surface coverages of hydroxy groups, which demonstrates that Cu2O octahedra with moderate coverage of hydroxy groups can indeed enhance the CO2RR and suppress the HER. [ABSTRACT FROM AUTHOR]

Abstract: Among the earliest Homo sapiens societies in Eurasia, the Aurignacian phase of the Early Upper Paleolithic, approximately 40 000–30 000 years ago, mammoth ivory assumed great social and economic significance, and was used to create hundreds of personal ornaments as well as the earliest known works of three‐dimensional figurative art in the world. This paper reports on the results of micro‐PIXE/PIGE analyses of mammoth‐ivory artifacts and debris from five major sites of Aurignacian ivory use. Patterns of variable fluorine content indicate regionally distinctive strategies of ivory procurement that correspond to apparent differences in human–mammoth interactions. Preserved trace elements (Br, Sr, Zn) indicate that differences at the regional level are applicable to sourcing Paleolithic ivory at the regional scale. [ABSTRACT FROM AUTHOR]

Abstract: Louis Ducos du Huron (1837–1920) dedicated his entire life to the elaboration of physical–chemical processes for color photography. This study aimed at highlighting his unique contribution to three‐color printing through 1) an in‐depth review of the many protocols he published and 2) the synchrotron‐based IR and X‐ray microanalysis of fragments sampled in three artworks. Ducos du Hauron's method relied on the preparation and assembly of three monochromes (red, blue, yellow). This study brings to light complex multistep recipes based on photochemistry (carbon print), organic, and inorganic chemistry. The various ingredients involved (e.g., pigments, dichromate gelatin, collodion, resin) were identified and localized through their spectroscopic signature, confirming the relevance of synchrotron spectromicroscopy for the characterization of historical photographs. The impressive correlation between texts and chemical analyses calls for a wider application to the history of photography. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical reduction of carbon dioxide (CO2) into value‐added chemicals is a promising strategy to reduce CO2 emission and mitigate climate change. One of the most serious problems in electrocatalytic CO2 reduction (CO2R) is the low solubility of CO2 in an aqueous electrolyte, which significantly limits the cathodic reaction rate. This paper proposes a facile method of catholyte‐free electrocatalytic CO2 reduction to avoid the solubility limitation using commercial tin nanoparticles as a cathode catalyst. Interestingly, as the reaction temperature rises from 303 K to 363 K, the partial current density (PCD) of formate improves more than two times with 52.9 mA cm−2, despite the decrease in CO2 solubility. Furthermore, a significantly high formate concentration of 41.5 g L−1 is obtained as a one‐path product at 343 K with high PCD (51.7 mA cm−2) and high Faradaic efficiency (93.3 %) via continuous operation in a full flow cell at a low cell voltage of 2.2 V. [ABSTRACT FROM AUTHOR]

Abstract: Supported vanadium oxides are one of the most promising alternative catalysts for propane dehydrogenation (PDH) and efforts have been made to improve its catalytic performance. However, unlike Pt‐based catalysts, the nature of the active site and surface structure of the supported vanadium catalysts under reductive reaction conditions still remain elusive. This paper describes the surface structure and the important role of surface‐bound hydroxyl groups on VOx / γ‐Al2O3 catalysts under reaction conditions employing in situ DRIFTS experiments and DFT calculations. It is shown that hydroxyl groups on the VOx /Al2O3 catalyst (V−OH) are produced under H2 pre‐reduction, and the catalytic performance for PDH is closely connected to the concentration of V−OH species on the catalyst. The hydroxyl groups are found to improve the catalyst that leads to better stability by suppressing the coke deposition. [ABSTRACT FROM AUTHOR]

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B My motto is b "Whatever is worth having is worth working for." B My greatest achievement has been b the birth of my son. I "The most important factor in the choice of my current research topic was wanting to develop functional materials for practical use ... My motto is 'Whatever is worth having is worth working for.' i " Find out more about Colleen N. Scott in her Introducing ... Profile. Behind the Science The idea behind the paper came from a conversation with co-author Prof. Jeff Chan following the development of our NIR II dyes. [Extracted from the article]

I "The next big goal of my research is to explore more efficient strategies for the ring-opening polymerization of macrocyclic monomers ... I am waiting for the day when someone will discover a new code table beyond the periodic table, bringing us to think about the chemical world in a different way." i Find out more about Hanchu Huang in his Introducing ... Profile. The idea of the "click polymerization trigger" behind our paper came about while exploring the anionic ring-opening polymerization of macrocyclic allylic sulfides. B The most important factor in the choice of my current research topic was b recognizing that achieving ring-opening polymerization of various macrocyclic monomers would be exciting. [Extracted from the article]

I "The most exciting thing about my research is manipulating renewable energy and chemical feedstock at the nanoscale to create useful molecules... To improve my work-life balance, I ask my team members to have work-life balance too, especially over the weekend...." i Find out more about Hiang Kwee Lee in his Introducing ... Profile. B The most exciting thing about my research is b manipulating renewable energy and chemical feedstock at the nanoscale to create useful molecules. Siew Kheng Boong (the first author of the paper) and I thus came up with the idea to squeeze light at the nanoscale by creating a superlattice-based plasmonic catalyst. [Extracted from the article]

We have achieved the divergent total synthesis of four kopsane alkaloids which share a complex heptacyclic caged ring system. Key transformations include an asymmetric Diels–Alder reaction to assemble the central bicyclo[2.2.2]octane moiety and the quaternary stereocenter at C20, a SmI2‐mediated cascade reduction/aldol reaction to construct the five‐membered ring and the quaternary stereocenter at C7, and a late‐stage cascade reductive amination/cyclization to establish the highly strained caged ring system. [ABSTRACT FROM AUTHOR]

An introduction is presented in which editor discusses various reports within the issue on topics including the benefits of double-blind reviewing in the scholarly community, the process of double-blind review, and contributors in the writing of a journal.

The article profiles Eric N. Jacobsen, Sheldon Emery professor of chemistry at Harvard University. Information on Jacobsen's educational background, awards, research interests and hobbies is presented. His views on friends, using a one-year paid leave, students and greatest scientific advance of the last decades are mentioned.