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We report a method to detect proteins via suppression of rolling circle amplification (RCA) by using an appropriate aptamer as the linear primer (denoted as an aptaprimer) to initiate RCA. In the absence of a protein target, the aptaprimer is free to initiate RCA, which can produce long DNA products that are detected via binding of a fluorescent intercalating dye. Introduction of a target causes the primer region within the aptamer to become unavailable for binding to the circular template, inhibiting RCA. Using SYBR Gold or QuantiFluor dyes as fluorescent probes to bind to the RCA reaction product, it is possible to produce a generic protein‐modulated RCA assay system that does not require fluorophore‐ or biotin‐modified DNA species, substantially reducing complexity and cost of reagents. Based on this modulation of RCA, we demonstrate the ability to produce both solution and paper‐based assays for rapid and quantitative detection of proteins including platelet derived growth factor and thrombin. [ABSTRACT FROM AUTHOR]

Congratulations to the GDCh: This issue of Chemistry—A European Journal celebrates the 150th anniversary of the German Chemical Society (GDCh). Members of the GDCh have played pivotal roles in the development of Chemistry—A European Journal and together with our other European partners have been instrumental in the success of the family of ChemPubSoc Europe journals. [ABSTRACT FROM AUTHOR]

EPR spectroscopic evidence for intramolecular electron transfer in anionic N‐substituted naphthalimides to yield persistent diradical anions and intermolecular electron transfer from a variety of carbanions to 6‐bromo‐N‐phenyl‐naphthalimide to yield persistent radical–radical anion pairs was recently claimed in two papers by Zhang et al. In this comment, it is shown that the EPR spectra published in both papers do not agree with the proposed triplet‐state species. Rather, the spectra are due to various doublet‐state radicals, deriving from minor side reactions. The misinterpretations invalidate the general conclusions of the papers. [ABSTRACT FROM AUTHOR]

A foldable battery with high flexibility provides great potential in various wearable electronic devices for health and fitness tracking, chronic disease management, performance monitoring, navigation tracking, and portable gears for soldiers. We report a highly flexible, self‐healing Zn‐ion battery with a free‐standing cathode that is composed of a 3D gear‐like NH4V4O10@C composite on carbon paper. The battery retained a capacity of up to 102.4 mAh g−1 even after being folded 60 times with a high angle of 180°. An aqueous hydrogel consisting polyvinyl alcohol, glycerin and Zn(CF3SO3)2 was used as electrolyte, which showed as high as 580 % tensile strain under a loading weight of 78 N. The battery exhibited a better capacity retention of over 100 mAh g−1 and Coulombic efficiency of over 99.8 % after cutting and twisting to 90°, thereby indicating a great self‐healing performance. The gear‐like geometry greatly improved the volume accommodation due to the increased interval space between the blades and the outward configuration. Meanwhile the Zn2+ ionic conductivity was improved by rapid re‐binding of many existing hydroxy groups from the electrolyte and the enhanced contact surface area and diffusion route from the cathode material. The highly flexible, safe aqueous Zn‐ion battery opens a practical way to power various carry‐on electronics under mechanical agitation. [ABSTRACT FROM AUTHOR]

The templated synthesis of ultralong hydroxyapatite nanowires@metal–organic framework core/shell (HAP@MIL‐100(Fe)) nanofibers has been demonstrated herein. The HAP@MIL‐100(Fe) nanofibers exhibited peroxidase‐like activity towards the oxidation of different peroxidase substrates in the presence of H2O2 accompanying with the clear color change of the solution. A new kind of flexible test paper was prepared by using HAP@MIL‐100(Fe) nanofibers as building blocks, which can be used for the detection of H2O2 and glucose, and it can be easily recovered, exhibiting excellent recyclability and promising applications in various fields. More information can be found in the Full Paper by Y.‐J. Zhu and Z.‐C. Xiong et al. on page 3328 ff. [ABSTRACT FROM AUTHOR]

The crystallization of a complex having electron transfer properties in a polar space group can induce the polarization switching of a crystal in a specific direction, which is attractive for the development of sensors, memory devices, and capacitors. Unfortunately, the probability of crystallization in a polar space group is usually low. Noticing that enantiopure compounds crystallize in Sohncke space groups, this paper reports a strategy for the molecular design of non‐ferroelectric polarization switching crystals based on the use of intramolecular electron transfer and chirality. In addition, this paper describes the synthesis of a mononuclear valence tautomeric (VT) cobalt complex bearing an enantiopure ligand. The introduction of enantiomer enables the crystallization of the complex in the polar space group (P21). The polarization of the crystals along the b‐axis direction is not canceled out and the VT transition is accompanied by a change in the macroscopic polarization of the polar crystal. Polarization switching via electron transfer is realized at around room temperature. [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]

1,2‐benzisothiazol‐3(2H)‐one derivatives are highly active against a broad spectrum of fungi as well as Gram positive and Gram negative bacteria. For this reason they are extensively used, for example, as additives in detergents, leather products, paper coatings, and antifouling paintings. In this paper experimental findings are reported proving that the sulfur atom of benzisothiazolinones have a remarkable tendency to form short and directional chalcogen bondings on the extension of the covalent N−S bond and, to a lesser extent, of the C−S bond. Analyses of the Cambridge Structural Database confirm the interaction as a primary recognition motif of these systems. The electrophilicity of sulfur is crucial in the chemical reactions initiating the cascade of events resulting in the biopharmacological activities of benzisothiazolinones. The reported results suggest that the electrophility of sulfur may play a role also at earlier stages than the reactive ones, namely it may pin the compounds at the active site of target enzymes via chalcogen bondings that preorganize the system in the conformation required for the bonds formation/cleavage determining the biopharmacological activity [ABSTRACT FROM AUTHOR]

William Henry Perkin, Jr. FRS, the son of the inventor of mauve and other commercial dyes and credited for initiating the industrialization of chemistry, was himself a notable chemist. He was the Professor of Organic Chemistry at Manchester from 1892–1912 and then was the Waynflete Professor of Chemistry at Oxford and the first Head of the Dyson Perrins Laboratory from 1912–1929. One of Perkin's graduate students and research assistants at Manchester was Robert Robinson, subsequently Sir Robert Robinson, FRS and recipient of the 1947 Nobel Prize in Chemistry. Perkin and Robinson had perhaps the most productive and broad collaboration between a professor and one's student. Together, during and after Robinson's student days, they had 71 joint publications, 25 of which involved just the two of them, 17 of which involved the structure determination of strychnine, and eight of which were published after Perkin's death in 1929. Upon Perkin's early death, Robinson succeeded him as the fourth Waynflete Professor of Chemistry at the Dyson Perrins Laboratory, Oxford University. This Essay will examine the professional relationship of Perkin, Jr. and Robinson as revealed in their joint publications on the structure of strychnine. [ABSTRACT FROM AUTHOR]

Recently, resistance random access memories (RRAMs) have been studied extensively, because the demand for information storage is increasing. However, it remains challenging to obtain a flexible device because the active materials involved need to be nontoxic, nonpolluting, distortion‐tolerable, and biodegradable as well adhesive to diverse flexible substrates. In this paper, tannic acid (TA) and an iron ion (FeIII) coordination complex were employed as the active layer in a sandwich‐like (Al/active layer/substrate) device to achieve memory performance. A nontoxic, biocompatible TA‐FeIII coordination complex was synthesized by a one‐step self‐assembly solution method. The retention time of the TA‐FeIII memory performance was up to 15 000 s, the yield up to 53 %. Furthermore, the TA‐FeIII coordination complex can form a high‐quality film and shows stable ternary memory behavior on various flexible substrates, such as polyethylene terephthalate (PET), polyimide (PI), printer paper, and leaf. The device can be degraded by immersing it in vinegar solution. Our work will broaden the application of organic coordination complexes in flexible memory devices with diverse substrates. Flexible memory: Tannic acid (TA) and an iron (FeIII) coordination complex were employed as an active layer in a sandwich‐like (Al/active layer/substrate) device to achieve memory performance. A nontoxic, biocompatible TA‐FeIII coordination complex was synthesized by a one‐step self‐assembly solution method. This complex can form a film on various flexible substrates (PET, PI, paper, and leaf) and all display ternary memory performance (see graphic). [ABSTRACT FROM AUTHOR]

"Swift fly the years", wrote Alexander Pope. I, for one, feel that 2018, my first full year as Editor‐in‐Chief of Chemistry—A European Journal, flew swiftly indeed. Looking back, the editorial team has accomplished a lot in 2018: We published nearly 2400 papers, more than 200 of which were Reviews, Minireviews or Concepts. Notwithstanding the growth in submitted and published papers we were able to handle manuscripts rapidly. [ABSTRACT FROM AUTHOR]

Certain properties of an object only emerge when a sufficient number of those objects are present in a definite arrangement. For example, one or two water molecules cannot said to be in a liquid state, but a drop of water can be. This concept of emergence has been studied extensively, but only occasionally discussed explicitly in the context of chemistry. In this paper, we aim to show the fruitfulness of the concept of emergence for chemical inquiry by considering four case studies of emergent chemical properties, i. e., the liquidity and freezing of water, structural properties of crystals, thermodynamical phase transitions and quantum mechanical phenomena. We show that some of these properties emerge gradually, some at discrete points, and some should be taken to emerge only when the number of constituents tends to infinity. We argue that studying the way in which chemical properties emerge presents a useful avenue for research that promises greater insight into the nature of those properties. [ABSTRACT FROM AUTHOR]

In this paper, Pd‐catalyzed [4+2] decarboxylative cycloaddition of 4‐vinylbenzodioxinones with barbiturate‐derived alkenes has been developed, leading to various spirobarbiturate−chromane derivatives in high yields with excellent diastereo‐ and enantioselectivities. The scale‐up reaction and further derivation of the product were demonstrated. A plausible reaction mechanism was also proposed. [ABSTRACT FROM AUTHOR]

MXenes have unique properties such as high electrical conductivity, excellent mechanical properties, rich surface chemistry, and convenient processability. These characteristics make them ideal for producing flexible materials with tunable microstructures. This paper reviews the laboratory research progress of flexible MXene and its composite materials for supercapacitors. And introduces the general synthesis method of MXene, as well as the preparation and properties of flexible MXene. By analyzing the current research status, the electrochemical reaction mechanism of MXene was explained from the perspectives of electrolyte and surface terminating groups. This review particularly emphasizes the composite methods of freestanding flexible MXene composite materials. The review points out that the biggest problem with flexible MXene electrodes is severe self‐stacking, which reduces the number of chemically active sites, weakens ion accessibility, and ultimately lowers electrochemical performance. Therefore, it is necessary to composite MXene with other electrode materials and design a good microstructure. This review affirms the enormous potential of flexible MXene and its composite materials in the field of supercapacitors. In addition, the challenges and possible improvements faced by MXene based materials in practical applications were also discussed. [ABSTRACT FROM AUTHOR]

[1]Benzothieno[3,2‐b][1]benzothiophenes (BTBTs) are important molecules that have been extensively studied as high‐performance organic field‐effect transistors (OFETs). Therefore, it is important to develop a simple synthetic method for these molecules. In this paper, a synthetic method to obtain the BTBTs from 2‐arylbenzo[b]thiophenes and elemental sulfur, in which two C−S bonds are formed at once, is described. In this method, molecular iodine plays a very important role as an additive. The role of iodine is discussed in the presumed reaction pathways. [ABSTRACT FROM AUTHOR]

Cinnamic ester is a common and abundant chemical substance, which can be extracted from natural plants. Compared with traditional esters, cinnamic ester contains α,β‐unsaturated carbonyl structure with multiple reactive sites, resulting in more abundant reactivities and chemical structures. Here, a versatile polymerization‐induced emission (PIE) is successfully demonstrated through Barbier polymerization of cinnamic ester. Attributed to its abundant reactivities of α,β‐unsaturated carbonyl structure, Barbier polymerization of cinnamic esters with different organodihalides gives polyalcohol and polyketone via 1,2‐addition and 1,4‐addition, respectively, which is also confirmed by small molecular model reactions. Meanwhile, these organodihalides dependant polyalcohol and polyketone exhibit different non‐traditional intrinsic luminescence (NTIL) from aggregation‐induced emission (AIE) type to aggregation‐caused quenching (ACQ) type, where novel PIE luminogens (PIEgens) are revealed. Further potential applications in explosive detection are carried out, where it achieves TNT detection sensitivity at ppm level in solution and ng level on the test paper. This work therefore expands the structure and functionality libraries of monomer, polymer and NTIL, which might cause inspirations to different fields including polymer chemistry, NTIL, AIE and PIE. [ABSTRACT FROM AUTHOR]

"Carbon Peak and Carbon Neutrality" is an important strategic goal for the sustainable development of human society. Typically, a key means to achieve these goals is through electrochemical energy storage technologies and materials. In this context, the rational synthesis and modification of battery materials through new technologies play critical roles. Plasma technology, based on the principles of free radical chemistry, is considered a promising alternative for the construction of advanced battery materials due to its inherent advantages such as superior versatility, high reactivity, excellent conformal properties, low consumption and environmental friendliness. In this perspective paper, we discuss the working principle of plasma and its applied research on battery materials based on plasma conversion, deposition, etching, doping, etc. Furthermore, the new application directions of multiphase plasma associated with solid, liquid and gas sources are proposed and their application examples for batteries (e. g. lithium‐ion batteries, lithium‐sulfur batteries, zinc‐air batteries) are given. Finally, the current challenges and future development trends of plasma technology are briefly summarized to provide guidance for the next generation of energy technologies. [ABSTRACT FROM AUTHOR]

Hydrogen‐bonded organic frameworks (HOFs) are a class of crystalline framework materials assembled by hydrogen bonds. HOFs have the advantages of high crystallinity, mild reaction conditions, good solution processability, and reproducibility. Coupled with the reversibility and flexibility of hydrogen bonds, HOFs can be assembled into a wide diversity of crystalline structures. Since the bonding energy of hydrogen bonds is lower than that of ligand and covalent bonds, the framework of HOFs is prone to collapse after desolventisation and the stability is not high, which limits the development and application of HOFs. In recent years, numerous stable and functional HOFs have been developed by π–π stacking, highly interpenetrated networks, charge‐assisted, ligand‐bond‐assisted, molecular weaving, and covalent cross‐linking. Charge‐assisted ionic HOFs introduce electrostatic attraction into HOFs to improve stability while enriching structural diversity and functionality. In this paper, we review the development, the principles of rational design and assembly of charge‐assisted ionic HOFs, and introduces the different building block construction modes of charge‐assisted ionic HOFs. Highlight the applications of charge‐assisted ionic HOFs in gas adsorption and separation, proton conduction, biological applications, etc., and prospects for the diverse design of charge‐assisted ionic HOFs structures and multifunctional applications. [ABSTRACT FROM AUTHOR]

Synthesis of diverse sterically congested molecules from a single important intermediate is one of the ideal synthetic strategies in organic synthesis. In this paper, we found that γ‐oxoalkyl substituted cyclohexenone derivatives (OAC) possessing a quaternary carbon are a useful key intermediate to derive both congested fused [5,6] rings and spirocycles. For this purpose, we have established an efficient synthetic method to obtain OAC by tertiary alkylation of β‐methylcyclohexenone derivatives using α‐bromocarbonyl compounds as a tertiary alkyl source. The key to the success of this reaction is controlling the reactivity of the dienamine intermediate. While there have been many reports on enamine reactions, dienamine reactions have not been well studied. Herein, we report controlling reactivity of dienamines and molecular diversification from OAC. [ABSTRACT FROM AUTHOR]

This paper presents a one‐step photochemical method for the preparation of CdS/Poly(MMA‐co‐MAA) composite photocatalyst, based on the concept of simultaneous photocatalytic polymerization of organic monomers during UV‐light induced formation of CdS. The preparation is carried out in an aqueous solution of Na2S2O3, CdSO4, methyl methacrylate (MMA) and methacrylic acid (MAA), under a UV lamp. The continuously formed CdS particles with photocatalytic activity act the role of initiator to directly initiate the copolymerization of MMA and MAA, resulting in the in situ formation of the composite and full contact of the CdS particles with the oxygen‐containing groups in the polymer. Taking the photocatalytic degradation of methylene blue as a case study, the composite exhibited significantly higher activity under simulated solar light compared to the pure CdS. By analysis on various data, the enhanced photocatalytic activity is attributed to the enhanced visible light absorption, and especially the high electron‐hole separation efficiency caused by the electrostatic interaction between photogenerated holes and carbonyl oxygen atoms with negatively charged features. Furthermore, the composite displays excellent sunlight activity and recyclability, suggesting its potential for practical applications. Such a one‐step construction strategy relying only on photo‐energy is green, low‐cost and promising in obtaining high‐performance semiconductor/polymer composite photocatalysts. [ABSTRACT FROM AUTHOR]

This article introduces a special collection of papers dedicated to Maurizio Prato, a renowned scientist in the field of carbon nanostructures and molecular nanoscience. The collection showcases Prato's team's achievements in integrating complex frontier research with groundbreaking advancements in these fields. Prato's work focuses on designing and synthesizing carbon nanostructures for applications in regenerative medicine and solar energy research. The article highlights Prato's scientific journey, his contributions to sustainable materials, and his impact on shaping functional nano-interfaces through precision chemistry. The Prato lab has made significant contributions to nanotechnology, particularly in the area of functionalized carbon nanotubes (f-CNT). Their research has shown that f-CNT are more biocompatible and easily cleared from the body compared to nonfunctionalized CNT. The lab has applied this knowledge to develop solutions for challenging problems such as healing spinal cord injuries and using water as a solar fuel. Their work in regenerative medicine has shown promising results in repairing severe and irreversible nervous system lesions, while their research in energy conversion has explored the use of f-CNT for solar energy conversion. Maurizio Prato, the leader of the lab, has fostered an interdisciplinary and collaborative environment, encouraging his team to explore diverse research avenues and promoting intellectual freedom. His mentorship and open-mindedness have been instrumental in the lab's success. [Extracted from the article]

Distyrylbenzenes (DSBs) are well‐known for their strong multicolour fluorescence. Fluorescence tuning of DSB via further functionalization/arylation, on the other hand, is uncommon. This paper reports a Pd‐catalysed direct arylation approach for introducing different aryl groups onto fluorobenzene‐containing DSB moiety (7) in high yields (67–72 %). The versatile methodology allows the substitution of neutral [tolyl (1)], electron‐deficient [p‐formyl benzene (2), p‐acetyl benzene (3), p‐nitrobenzene (4)] and electron‐rich [carbazole (5), triphenylamine (6)] aryl groups. The electron‐deficient aryls render mono‐substitution, while the electron‐rich counterparts promote di‐substitution. The compounds (1–6) show blue, green, and yellow fluorescence in both the solution and solid states; the fluorescence quantum yields reach >98 % and the peak maxima span from 425 to 560 nm. The mono‐carbazole DSB (5) exhibit white light emission (WLM) in polar solvents (acetone, DMF, CH3CN, DMSO and NMP) with very high fluorescence quantum yields (φf) of 60–80 %. For WLM, such high efficiency (φf) is somewhat uncommon. Moreover, visible‐to‐NIR reversible electrochromism is demonstrated by the TPA‐integrated DSB (6). The colour of 6 changes from pristine light yellow to orange, and the absorption maxima shifts from 372 to 1500 nm when a positive potential of 1.0 V vs Ag/Ag+ is applied. Moreover, the system shows high colouration efficiency in the NIR region with fast switching speeds for colouration and decolouration as fast as 0.98 s and 1.05 s. [ABSTRACT FROM AUTHOR]

Among many problems of a fundamental value in the heteroatom chemistry the mechanism and stereochemistry of the nucleophilic substitution reaction at the phosphorus and other heteroatom centres have attracted great attention of phosphorus chemists already in the middle of the last century. This review, which does not have a comprehensive character, summarizes the selected original contributions aimed at solution of the mechanism of SN2−P reaction and its relationship with stereochemistry. The breakthrough in these studies was the Westheimer's concept and his rules which is presented at the beginning of this article. Next, a series of papers is presented where the stereochemistry of the substitution at phosphorus was investigated in cyclic five‐, four‐ and six‐membered ring phosphorus compound. The majority of these reactions have been found to occur with retention of the P‐configuration. In the third part of this account, the selected examples of substitution reactions at phosphorus in acyclic compounds are discussed. As the results of all the investigations discussed did not allow to undoubtedly ascribe the mechanism (SN2 or A−E) to the investigated reactions, in the last part the SN‐P reactions are presented, the mechanism of which has been established by combination of the stereochemical and DFT‐studies. [ABSTRACT FROM AUTHOR]

Fluorescent polymeric materials have been exploited in the fields of aesthetical purposes, biomedical engineering, and three‐dimensional printing applications. While the fluorescent materials are prepared by the polymerization of fluorescent monomer or the blending a fluorescent dye with common polymer, the covalent immobilization of fluorescent dye onto common polymers is not the practical technique. In this paper, dansylated nitrile N‐oxide (Dansyl‐NO) has been designed and synthesized to be a stable nitrile N‐oxide as the derivative of 2‐hydroxy‐1‐naphthaldehyde. While Dansyl‐NO shows good reactivity to an alkene and an alkyne to give fluorescent Dansyl‐Ene and Dansyl‐Yne, respectively, it hardly reacts to a nitrile. The results indicate that Dansyl‐NO serves as a fluorescent dye clickable to alkenes and alkynes. To know the effects of solvent on the fluorescent properties, the UV‐vis and fluorescence spectra of Dansyl‐Ene are measured in three solvents. Dansyl‐Ene shows fluorescent solvatochromism, which appears to be red‐shifted along with the increase in solvent polarity. Poly(styrene‐co‐butadiene) directly reacts with Dansyl‐NO to give fluorescent modified SB. The emission spectrum of modified SB is blue‐shifted compared with that of Dansyl‐Ene. The blue‐shift could be possibly attributed to the presence of less polar polymer skeleton around the dansyl moieties of modified SB. [ABSTRACT FROM AUTHOR]

Tumor immunotherapy, represented by immune checkpoint blocking and chimeric antigen receptor (CAR) T cell therapy, has achieved promising results in clinical applications. However, it faces challenges that hinder its further development, such as limited response rates and poor tumor permeability. The efficiency of tumor immunotherapy is also closely linked to the structure and function of the immune microenvironment where the tumor resides. Recently, nanoparticle‐based tumor immune microenvironment (TIME) modulation strategies have attracted a great deal of attention in cancer immunotherapy. This is primarily due to the distinctive physical characteristics of nanoparticles, which enable them to effectively infiltrate the TIME and selectively modulate its key constituents. This paper reviews recent advances in nanoparticle engineering to improve anti‐cancer immunotherapy. Emerging nanoparticle‐based approaches for modulating immune cells, tumor stroma, cytokines and immune checkpoints are discussed, aiming to overcome current challenges in the clinic. In addition, integrating immunotherapy with various treatment modalities such as chemotherapy and photodynamic therapy can be facilitated through the utilization of nanoparticles, thereby enhancing the efficacy of cancer treatment. The future challenges and opportunities of using nanomaterials to reeducate the suppressive immune microenvironment of tumors are also discussed, with the aim of anticipating further advancements in this growing field. [ABSTRACT FROM AUTHOR]

This paper presents a green and efficient aqueous‐phase method for the synthesis of thiosulfonates, which has the benefits of no need for catalysts or redox reagents and a short reaction time, providing a method with great economic value for synthesizing thiosulfonates. Furthermore, 3‐Sulfenylindoles can be easily synthesized using this method, which expands the potential applications of this reaction. [ABSTRACT FROM AUTHOR]

Free radicals are increasingly recognized as active intermediate reactive species that can participate in various redox processes, significantly influencing the mechanistic pathways of reactions. Numerous researchers have investigated the generation of one or more distinct photogenerated radicals, proposing various hypotheses to explain the reaction mechanisms. Notably, recent research has demonstrated the emergence of photogenerated radicals in innovative processes, including organic chemical reactions and the photocatalytic dissolution of precious metals. To harness the potential of these free radicals more effectively, it is imperative to consolidate and analyze the processes and action modes of these photogenerated radicals. This conceptual paper delves into the latest advancements in understanding the mechanics of photogenerated radicals. [ABSTRACT FROM AUTHOR]

Owing to its high natural abundance compared to the commonly used transition (precious) metals, as well as its high Lewis acidity and ability to change oxidation state, aluminium has recently been explored as the basis for a range of single‐site catalysts. This paper aims to establish the ground rules for the development of a new type of cationic alkene oligomerisation catalyst containing two Al(III) ions, with the potential to act co‐operatively in stereoselective assembly. Five new dimers of the type [R2Al(2‐py′)]2 (R=Me, iBu; py′=substituted pyridyl group) with different substituents on the Al atoms and pyridyl rings have been synthesised. The formation of the undesired cis isomers can be suppressed by the presence of substituents on the 6‐position of the pyridyl ring due to steric congestion, with DFT calculations showing that the selection of the trans isomer is thermodynamically controlled. Calculations show that demethylation of the dimers [Me2Al(2‐py′)]2 with Ph3C+ to the cations [{MeAl(2‐py’)}2(μ‐Me)]+ is highly favourable and that the desired trans disposition of the 2‐pyridyl ring units is influenced by steric effects. Preliminary experimental studies confirm that demethylation of [Me2Al(6‐MeO‐2‐py)]2 can be achieved using [Ph3C][B(C6F5)4]. [ABSTRACT FROM AUTHOR]

[Gd(HP‐DO3A)] (gadoteridol) as an active compound of ProHance® is a widely employed contrast agent in clinical MRI scans in the last 30 years. Recent concerns about the long‐term retention of gadolinium‐based contrast agents (GBCAs) led to a deeper investigation of the structural features underlying the integrity of the paramagnetic metal complex. Several human and nonclinical studies have noted marked differences among the macrocyclic GBCAs, with the least retention of Gd traces and most rapid elimination consistently being reported for [Gd(HP‐DO3A)]. It was deemed of interest to assess how minor structural/electronic changes associated to the ligand structure may affect basic properties of the metal complex with several [Gd(HP‐DO3A)] analogues synthesized and characterized in the last years. We recently reported that the closest homolog of [Gd(HP‐DO3A)], i. e.: [Gd(HB‐DO3A)], in which a (±)‐2‐hydroxy‐1‐propyl pendant arm is replaced by a (±)‐2‐hydroxy‐1‐butyl moiety, showed a significantly different retention behaviour in the model interaction with collagen, despite the apparently very minor structural difference. In this paper we report a comprehensive study of the structural, thermodynamic, kinetic and relaxation properties of [Gd(HB‐DO3A)], compared to the parent [Gd(HP‐DO3A)] and to other closely related macrocyclic GBCAs to assess whether very minor structural changes can modulate the physico‐chemical properties of Gd3+ complexes. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of ruthenium‐based molecular gear prototypes composed of a brominated or non‐brominated pentaphenylcyclopentadienyl ligand as an anchoring unit and a tripodal ligand with aryl‐functionalized indazoles as a rotating cogwheel. Single crystal structures of the ruthenium complexes revealed that the appended aryl groups increase the apparent diameter of the cogwheel rendering them larger than the diameter of the anchoring units and consequently making them suitable for intermolecular gearing motions once the complexes will be adsorbed on a surface. [ABSTRACT FROM AUTHOR]

This paper provides the first report of the intramolecular [2+2] cycloaddition of vinylsilane. The [2+2] cycloaddition of allenes is a useful reaction that can synthesize cyclobutanes. However, no previous works have attempted to control the regioselectivity between the two double bonds of allenes only by changing the reaction conditions, although there have been some reports of the regioselective [2+2] cycloaddition of allenes by changing the substrate. In this study, we have succeeded in controlling intramolecular [2+2] cycloaddition reactions at the proximal and distal positions of allenes simply by changing the reaction conditions. We found that the atomic radius of silicon is very important for perfect control of the reaction's sites. The structures of all key compounds were determined by the crystal sponge method which could identify the structures of liquid compounds. [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: 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]

A response to the comment by Gernot Frenking, outlining common ground, as well as differences, with regard to a recent paper on charge-shift bonding in quaternary ammonium cations. [ABSTRACT FROM AUTHOR]

A thin film of poly-([IrCl(cod)(NHC-onbe)] n-(propyl-onbe) m) (onbe=oxanorbornene) coated on filter paper reacts quantitatively with CO to yield 1,5-cyclooctadiene, the unpleasant smell of which can be detected by the human olfactory system with very high sensitivity. Odorless, but toxic CO is thus 'translated' into the distinct smell of 1,5-cyclooctadiene. Based on malodorogenic sensing it is possible to smell the presence of CO. [ABSTRACT FROM AUTHOR]

Radical‐type mechanophores (RMs) can undergo homolytic cleavage of their central C−C bonds upon exposure to mechanical forces, which affords radical species. Understanding the characteristics of these radical species allows bespoke mechanoresponsive materials to be designed and developed. The thermal stability of the central C−C bonds and the oxygen tolerance of the generated radical species are crucial characteristics that determine the functions and applicability of such RM‐containing mechanoresponsive materials. In this paper, we report the synthesis and characterization of two series of arylfluorene‐based RM derivatives, that is, 9,9'‐bis(5‐methyl‐2‐pyridyl)‐9,9'‐bifluorene (BPyF) and 9,9'‐bis(4,6‐diphenyl‐2‐triazyl)‐9,9'‐bifluorene (BTAF). BPyF and BTAF derivatives were synthesized without generating any peroxides initially, albeit that BPyF slowly converted to the corresponding peroxide in solution. DFT calculations revealed the importance of the thermodynamic stability and the values of the α‐SOMO levels of the corresponding radical species for their thermal stability and oxygen tolerance. Furthermore, the mechanochromism of BTAF was demonstrated by ball‐milling a BTAF‐centered polymer, which was synthesized by atom‐transfer radical polymerization (ATRP). [ABSTRACT FROM AUTHOR]

Sodium manganese‐based oxides (NMO) are attracting huge attention as safe and cost‐effective cathode materials for sodium‐ion batteries (SIBs). To date, one of the most important challenges of NMO‐based cathodes is the relatively low capacity. Therefore, it is of great significance to develop high‐capacity NMO‐based cathodes. Great efforts have been made to enhance the reversible capacity of NMO‐based cathodes, achieving considerable progress not only on electrochemical performance, but also the mechanism of massive sodium ion storage. In this paper, the structure and sodium storage mechanism for typical phases of NMO are reviewed, including P2, P3, O3, tunnel‐type, and spinel‐type NMO‐based cathodes. Strategies for high‐capacity NMO‐based cathodes, such as cationic substitution, anion redox activation, etc are introduced in detail. Last but not least, the future opportunities and challenges for high‐capacity NMO‐based cathode are prospected. [ABSTRACT FROM AUTHOR]

The regioselective deiodinations of L‐thyroxine (T4) play key roles in the thyroid hormone homeostasis. These reactions are catalyzed by three isoforms of the selenoenzymes, iodothyronine deiodinases (Dio1, Dio2 and Dio3), which are highly homologous in nature. Dio1 mediates 5′‐ or 5‐deiodinations of T4 to produce T3 and rT3, respectively. In contrast, Dio2 and Dio3 are selective to 5′‐ or 5‐deiodination to produce T3 and rT3, respectively. Understanding of the regioselectivity of deiodination at the molecular level is important as abnormal levels of thyroid hormone have been implicated in various clinical conditions, such as hypoxia, myocardial infarction, neuronal ischemia and cancer. In this paper, we report that the electronic properties of the iodine atoms in thyroxine (T4) can be modulated through a simple substitution in the 4′‐phenolic moiety. This leads to the change in the regioselectivity of deiodination by different small molecule mimics of Dio enzymes. By using this chemical approach, we also show that the substitution of a strong electron withdrawing group facilitates the removal of all four iodine atoms in the T4 derivative. Theoretical investigations on the hydrogen bonded adducts of T4 with imidazole indicate that the charge on the iodine atoms depend on the nature of hydrogen bond between the −OH group of T4 and the imidazole moiety. While the imidazole can act as either hydrogen bond acceptor (HBA) or hydrogen bond donor (HBD), the protonated imidazole acts exclusively as HBD in T4‐imidazole complex. These studies support the earlier observations that the histidine residue at the active sites of the deiodinases play an important role not only in the substrate binding, but also in altering the regioselectivity of the deiodination reactions. [ABSTRACT FROM AUTHOR]

Nitrogenase is the enzyme that converts N2 to NH3 under ambient conditions. The chemical mechanism of this catalysis at the active site FeMo‐co [Fe7S9CMo(homocitrate)] is unknown. An obligatory co‐product is H2, while exogenous H2 is a competitive inhibitor. Isotopic substitution using exogenous D2 revealed the N2‐dependent reaction D2+2H++2e−→2HD (the 'HD reaction'), together with a collection of additional experimental characteristics and requirements. This paper describes a detailed mechanism for the HD reaction, developed and elaborated using density functional simulations with a 486‐atom model of the active site and surrounding protein. First D2 binds at one Fe atom (endo‐Fe6 coordination position), where it is flanked by H−Fe6 (exo position) and H−Fe2 (endo position). Then there is synchronous transfer of these two H atoms to bound D2, forming one HD bound to Fe2 and a second HD bound to Fe6. These two HD dissociate sequentially. The final phase is recovery of the two flanking H atoms. These H atoms are generated, sequentially, by translocation of a proton from the protein surface to S3B of FeMo‐co and combination with introduced electrons. The first H atom migrates from S3B to exo‐Fe6 and the second from S3B to endo‐Fe2. Reaction energies and kinetic barriers are reported for all steps. This mechanism accounts for the experimental data: (a) stoichiometry; (b) the N2‐dependence results from promotional N2 bound at exo‐Fe2; (c) different N2 binding Km for the HD reaction and the NH3 formation reaction results from involvement of two different sites; (d) inhibition by CO; (e) the non‐occurrence of 2HD→H2+D2 results from the synchronicity of the two transfers of H to D2; (f) inhibition of HD production at high pN2 is by competitive binding of N2 at endo‐Fe6; (g) the non‐leakage of D to solvent follows from the hydrophobic environment and irreversibility of proton introduction. [ABSTRACT FROM AUTHOR]