The synthesis of radical polymers with control over chemical composition and structure is a milestone in materials science and has re‐emerged recently because of the development of new synthetic methods to produce stable radical organic compounds. However, their synthesis is remarkably challenging due to the inherent reactivity induced by the presence of unpaired electrons in their structure. Here, we report on the synthesis and characterization of atomically precise one‐dimensional diradical peripentacene...
Sat Jun 27, 2020 13:50
Chemiluminescence (CL) sensing without the external excitation ligh t and autofluorescence interference has been applied to high‐contrast in vitro immunoassays and in vivo inflammation and tumor microenvironment detection. However, conventional CL sensing usually operates in the range of 400‐850 nm, which limits the high‐performance of in vivo imaging due to the serious light scattering effect and signals attenuation in tissue. To address this challenge, here we present a new type of CL...
Sat Jun 27, 2020 13:19
Expanding the application scope of single‐atom catalysts (SACs) to high‐temperature hydrogenation requires materials that thermodynamically favor metal atom isolation over cluster formation under these conditions. Here, we show that Pd can be predominantly dispersed as isolated atoms onto TiO 2 during the reverse water‐gas shift (rWGS) reaction at 400 °C. Achieving atomic dispersion requires an artificial increase of the absolute TiO 2 surface area by an order of magnitude and can be accomplished...
Fri Jun 26, 2020 22:49
We report a single‐molecule mechanistic investigation into 2‐cyanobenzothiazole (CBT) chemistry within a protein nanoreactor. When simple thiols reacted reversibly with CBT, the thioimidate monoadduct was ~80‐fold longer‐lived than the tetrahedral bisadduct, with important implications for the design of molecular walkers. The irreversible condensation between CBT derivatives and N‐terminal cysteine has been established as a biocompatible reaction for site‐selective biomolecular labeling and imaging....
Fri Jun 26, 2020 22:00
Calcium (Ca 2+ ), as a ubiquitous but nuanced modulator of cellular physiology, its level is meticulously controlled intracellularly. However, the intracellular Ca 2+ regulation, such as mitochondrial Ca 2+ buffering capacity, can be readily disrupted by 1 O 2 . Thus, the intracellular Ca 2+ overload, which is recognized as one of the important cell pro‐death factors, can be logically achieved by the synergism of 1 O 2 with exogenous Ca 2+ delivery. Reported herein is a nanoscale...
Fri Jun 26, 2020 21:19
Enantioselectivity in heterogeneous catalysis strongly depends on the chirality transfer between catalyst surface and all reactants, intermediates, and the product along the reaction pathway. Here we report the first enantioselective on‐surface synthesis of molecular structures from an intial racemic mixture and without the need of enantiopure modifier molecules. The reaction consists of a trimerization via an unidentified bonding motif of prochiral 9‐ethynylphenanthrene (9‐EP) upon annealing to...
Fri Jun 26, 2020 21:19
Fluorescently‐quenched probes that are specifically activated in the cancer microenvironment have great potential application for diagnosis, early detection and surgical guidance. These probes are often designed to target specific enzymes associated with disease by direct optimization using single purified enzymes. However, this can result in painstaking chemistry efforts to produce a probe with suboptimal performance when applied in vivo. We describe here an alternate, unbiased activity‐profiling...
Fri Jun 26, 2020 20:49
β‐Lactam antibiotics are generally perceived as one of the greatest inventions of the 20 th century, and these small molecular compounds have saved millions of lives. However, upon clinical application of antibiotics, the β‐lactamase secreted by pathogenic bacteria can lead to the gradual development of drug resistance . β‐Lactamase is a hydrolase that can efficiently hydrolyze and destroy β‐lactam antibiotics. It develops and spreads rapidly in pathogens, and the drug‐resistant bacteria pose...
Fri Jun 26, 2020 20:22
Separation of acetylene (C 2 H 2 ) from carbon dioxide (CO 2 ) or ethylene (C 2 H 4 ) is important in industry but challenged by the low capacity and selectivity due to their similar molecular sizes and physical properties. Herein, we report two novel dodecaborate‐hybrid metal organic frameworks, MB 12 H 12 (dpb) 2 (termed as BSF‐3 and BSF‐3‐Co for M = Cu and Co), for highly selective capture of C 2 H 2 . The high C 2 H 2 capacity and remarkable C 2 H 2 /CO 2 selectivity...
Fri Jun 26, 2020 18:20
To gain insight into chiral recognition in porous materials we have prepared a family of fourth generation chiral metal‐organic frameworks (MOFs) which exhibit rigid frameworks and adaptable (flexible) pores. The previously reported parent material, [Co 2 (S‐mandelate) 2 (4,4’‐bipyridine) 3 ](NO 3 ) 2 , CMOM‐ 1S , is a modular MOF; five new variants in which counterions (BF 4 ‐ , CMOM‐ 2S ) or mandelate ligands are substituted (2‐Cl, CMOM‐ 11R ; 3‐Cl, CMOM‐ 21R ; 4‐Cl, CMOM‐...
Fri Jun 26, 2020 18:20
Polyelectrolytes such as e.g. DNA or heparin are long linear or branched macromolecules onto which charges are appended. The counterions neutralizing these charges may dissociate in water and will largely determine the interaction of such polyelectrolytes with biomolecules and in particular with proteins. Here we review studies on the interaction of proteins with polyelectrolytes and how this knowledge can be used for medical applications. Counterion release was identified as the main driving force...
Fri Jun 26, 2020 17:52
The stereospecific 1,2‐migration of boronate complexes is one of the most representative reactions in boron chemistry. This process has been used extensively to develop powerful methods for asymmetric synthesis, with applications spanning from pharmaceuticals to natural products. Typically, 1,2‐migration of boronate complexes is driven by displacement of an α ‐leaving group, oxidation of an α ‐boryl radical, or electrophilic activation of an alkenyl boronate complex. The aim of this article is...
Fri Jun 26, 2020 16:52
Overproduction of superoxide anion (O 2 ∙ – ), the primary cellular reactive oxygen species (ROS), is implicated in various human diseases. To reduce cellular oxidative stress caused by overproduction of superoxide, we developed a compound that reacts with O 2 ∙ – to release a persulfide (RSSH), a type of reactive sulfur species related to the gasotransmitter hydrogen sulfide (H 2 S). Termed SOPD‐NAC , this persulfide donor reacts specifically with O 2 ∙ – , decomposing to generate...
Fri Jun 26, 2020 16:51
We report a high‐performance I+/H2O2 catalysis for the oxidative or decarboxylative oxidative α‐azidation of carbonyl compounds by using sodium azide under biphasic neutral phase transfer conditions. To induce higher reactivity especially for the α‐azidation of 1,3‐dicarbonyls, we designed a structurally compact isoindoline‐derived quaternary ammonium iodide catalyst bearing electron‐withdrawing groups. In addition, the non‐productive decomposition pathways of I+/H2O2 catalysis could be suppressed...
Fri Jun 26, 2020 12:37
Force to be reckoned with : The correlations between nanoscale electrical, chemical, structural, and mechanical surface properties were explored in perovskite and amyloid fibrils with intrinsically integrated peak force infrared and Kelvin probe force microscopies. Correlative nanoimaging serves as a useful tool for deciphering the important underlying causal relationships between properties in situ. Abstract Correlative scanning probe microscopy of chemical identity, surface potential,...
Thu Jun 25, 2020 22:00
Cyclobutanones are synthetically versatile compounds that often requires extensive effort to access. Herein, we report a facile synthesis of cyclobutanones based on the C(sp 3 )‐H insertion chemistry of oxidatively generated gold carbenes. A range of cyclobutanones was obtained in synthetically useful yields from substrates with minimal structural prefunctionalization. This discovery reveals new synthetic utilities of gold‐catalyzed oxidative transformations of alkynones.
Thu Jun 25, 2020 21:23
Elucidating the effects of crystallization induced blue shift emission of a newly synthesized di‐boron complex (DBC) by enhanced photoluminescence (PL) and electrochemiluminescence (ECL) in the annihilation pathway was realized for the first time. The 57 nm blue‐shift and great enhancement in the crystalline lattice relative to the DBC solution were attributed to the restriction of intramolecular rotation (RIR) and confirmed by PL imaging, x‐ray diffraction, as well as DFT calculations. It was discovered...
Thu Jun 25, 2020 20:50
Hydrogen peroxide (H 2 O 2 ) mediates the biology of wound healing, apoptosis, inflammation, etc. H 2 O 2 has been fluorometrically imaged with protein‐ or small molecule‐based probes. However, only protein‐based probes have afforded temporal insights within seconds. Small molecule‐based electrophilic probes for H 2 O 2 require many minutes for a sufficient response in biological systems. Here, we report a fluorogenic probe that selectively undergoes a [2,3]‐sigmatropic rearrangement...
Thu Jun 25, 2020 20:50
We describe a photoinduced copper‐catalyzed asymmetric radical decarboxylative alkynylation of bench‐stable N ‐hydroxyphthalimide(NHP)‐type esters of racemic alkyl carboxylic acids with terminal alkynes, providing a flexible platform for the construction of chiral C( sp 3 )‐C( sp ) bonds. Critical to the success of this process are not only the use of the copper catalyst as a dual photo‐ and cross‐coupling catalyst but also the tuning of NHP‐type esters to inhibit the easily‐occurring homodimerization...
Thu Jun 25, 2020 18:19
Nanoreactors with hollow structures have attracted great interest in catalysis research due to their void‐confinement effects. However, the challenge in unambiguously unraveling these confinement effects is to decouple them from other factors affecting the catalytic behaviors. Here, we synthesize a pair of hollow carbon sphere (HCS) nanoreactors with pre‐synthesized PdCu nanoparticles encapsulated inside of HCS (PdCu@HCS) and supported outside of HCS (PdCu/HCS), respectively, while keeping other...
Thu Jun 25, 2020 17:55
Oxidative coupling of methane (OCM) has been considered as one of the most promising and attractive catalytic technology to upgrade methane. However, C 2 products (C 2 H 6 /C 2 H 4 ) from conventional methane conversion have not yielded commercially due to the competition from overoxidation and carbon accumulation at high temperatures. Herein, we reported the co‐deposition of Pt nanoparticles and CuO x clusters on TiO 2 (PC‐50), and then used the photocatalyst to demonstrate the first...
Thu Jun 25, 2020 17:51
The right surfactant : The extent to which the surfactant coverage of two‐dimensional materials can influence functionalization reactions is elaborated. In a case study of the spontaneous reaction of chloroauric acid with WS2, preferential adsorption of certain surfactants can be exploited to exert control on regioselective functionalization. Abstract In recent years, various functionalization strategies for transition‐metal dichalcogenides have been explored to tailor the properties of...
Thu Jun 25, 2020 17:05
Ironing imines : The first iron‐catalyzed asymmetric reduction of N ‐alkyl imines is reported. A molecularly defined iron complex catalyzes the highly enantioselective hydroboration of various N ‐alkyl imines, providing access to the corresponding α‐chiral amines in high yields and stereoselectivities. The earth‐abundant metal catalyst was applied in the synthesis of the pharmaceuticals Fendiline and Tecalcet. Abstract A readily activated iron alkyl precatalyst effectively catalyzes the...
Thu Jun 25, 2020 17:03
Dual‐stress and thermally responsive crystalline metal–organic materials (MOMs) based on molecular spring‐like triple‐helix coordination polymers are presented. As the first example of thermosalient effect in elastic MOMs, these compounds undergo elastic flexure upon external stress as well as cracking and jumping after thermal treatment. Abstract Elastic metal–organic materials (MOMs) capable of multiple stimuli‐responsiveness based on dual‐stress and thermally responsive triple‐helix...
Thu Jun 25, 2020 17:02
The exsolution of CoFe alloy nanoparticles in La0.4Sr0.6Co0.2Fe0.7Mo0.1O3−δ perovskite is investigated at atomic scale using in situ scanning transmission electron microscopy with energy dispersive X‐ray spectroscopy and density functional theory calculations. Abstract In situ exsolution of metal nanoparticles in perovskite under reducing atmosphere is employed to generate a highly active metal–oxide interface for CO2 electrolysis in a solid oxide electrolysis cell. Atomic‐scale insight...
Thu Jun 25, 2020 17:01
“Chemistry is fun because it is a changing art. … My favorite time of day is sunset … ” Find out more about Xinping Wang in his Author Profile.
Thu Jun 25, 2020 17:01
Reactivity pathways of NacNacAl with various N‐heterocycles have been investigated and diverse and highly substrate‐controlled reactivity patterns have been discovered. Cases of unusual sp3 and sp2 C−H bond activation, C−C coupling, and N−N bond cleavage are reported. NacNac=[ArNC(Me)CHC(Me)NAr]−, Ar=2,6‐i Pr2C6H3. Abstract The aluminum(I) compound NacNacAl (NacNac=[ArNC(Me)CHC(Me)NAr]−, Ar=2,6‐i Pr2C6H3, 1 ) shows diverse and substrate‐controlled reactivity in reactions with N‐heterocycles....
Thu Jun 25, 2020 16:59
Preparation of supported metal catalysts with uniform particle size and coordination environment is a challenging and important topic in materials chemistry and catalysis. In this work, we report the regioselective generation of single‐site Ir atoms and their evolution into stabilized subnanometric Ir clusters in MWW zeolite, which are located at the 10MR window connecting the two neighboring 12MR supercages. The size of the subnanometric Ir clusters can be controlled by the post‐synthesis treatments...
Thu Jun 25, 2020 13:28
A liquid crystalline elastomer strip can expand in both length and width on cooling and shrink along the two directions on heating over order–disorder phase transition. Abstract Liquid crystalline elastomers (LCEs) have been actively investigated as stimuli‐controlled actuators and soft robots. The basis of these applications is the ability of LCEs to undergo a reversible shape change upon a liquid crystalline (LC)‐isotropic phase transition. Herein, we report the synthesis of a novel...
Thu Jun 25, 2020 12:49
A non‐alternant isomer of terrylene bisimide was synthesized by palladium‐catalyzed [3+3] annulation of azulene and naphthalimide. It was functionalized by simple bromination and nucleophilic substitution. These π‐extended azulenes show NIR absorptions and planar geometries with an aromatic azulene moiety, as confirmed by crystallographic analysis and theoretical calculations. Abstract The first planar π‐extended azulene that retains aromaticity of odd‐membered rings was synthesized by...
Thu Jun 25, 2020 12:48
Passing through : Reported for the first time is the successful in situ biomineralization of an enzyme‐containing metal–organic framework (MOF) layer on a polymeric hollow fiber in a facile one‐step process. The interconnection between an enzymatic active layer and a porous membrane overcomes stability drawbacks, removes the need for MOF separation, and leads to increased enzyme activity as a result of the improved mass transport by permeation. Abstract Metal–organic frameworks (MOFs) are...
Thu Jun 25, 2020 12:48
Plastic fantastic : Plastic can rise again and again as a new product. Researchers now know methods with which new plastics can be produced from 100 % recycled material, products that can even be used for food applications. This development is possible thanks to chemical recycling, through which polymer chains are first broken to then be reformed into new molecules, such as plastics but also other chemicals. Abstract Increasing the stream of recycled plastic necessitates an approach beyond...
Thu Jun 25, 2020 12:47
Novel organic lasers were fashioned from large, aggregation‐free polycyclic aromatic hydrocarbons (PAHs). Several new perylene‐based PAHs were prepared that show perylene‐like electronic properties with moderate fluorescence quantum yields. Two of them show amplified spontaneous emission, and solution‐processed distributed feedback lasers were successfully fabricated. Abstract Perylene‐fused, aggregation‐free polycyclic aromatic hydrocarbons with partial zigzag periphery (ZY‐01 , ZY‐02...
Thu Jun 25, 2020 12:45
Reversible regulation of membrane microstructures via non‐covalent interactions is of considerable interest yet remains a challenge. Herein, we discover a general one‐step approach to fabricate supramolecular porous polyelectrolyte membranes (SPPMs) from a single poly(ionic liquid) (PIL). The experimental results and theoretical simulation suggested that SPPMs were formed by a hydrogen bond‐induced phase separation of a PIL between its polar and apolar domains, which were linked together by water...
Thu Jun 25, 2020 12:44
The reactions of laser‐ablated beryllium atoms with dinitrogen and carbon monoxide mixtures form the end‐on bonded NNBeCO and side‐on bonded (η 2 ‐N 2 )BeCO isomers in solid argon, which are predicted by quantum chemical calculations to be almost isoenergetic. The end‐on bonded complex has a triplet ground state while the side‐on bonded isomer has a singlet electronic ground state. The complexes rearrange to the energetically lowest lying NBeNCO isomer upon visible light excitation, which is...
Thu Jun 25, 2020 11:46
<div class="abstract"> <p> <div><div class="abstract"> <p> <div><div class="abstract"> <p> <div><div class="abstract"> <p> <div><div class="abstract"> <p> <div>Mild mono‐ and di‐hydrodehalogenative reductions of gem‐dibromocyclopropanes are described, providing an easy and green approach towards the synthesis of cyclopropanes. The methodology utilizes 0.5‐5 mol % TMPhen‐nickel as catalyst that, when activated...
Wed Jun 24, 2020 22:43
A general and efficient approach for the preparation of 1,3‐bis‐(boryl)alkanes is introduced. It is shown that readily generated vinylboron ate complexes react with commercially available ICH 2 Bpin to valuable 1,3‐bis‐(boryl)alkanes. The introduced transformation which is experimentally easy to conduct shows broad substrate scope and high functional group tolerance. Mechanistic studies reveal that the reaction does not proceed via radical intermediates. Instead, an unprecedented boronic ester‐induced...
Wed Jun 24, 2020 22:00
As an emerging optical material, perovskite nanocrystals (NCs) exhibit excellent optoelectronic properties and show great potential for various optoelectronic applications. However, the inherent inferior stability against moisture, oxygen, light and heat limit their practical application. As well, the exploration and development of perovskite NCs with novel properties and functions are newly opened challenges. To achieve these goals, the integration and encapsulation of perovskite NCs with multifunctional...
Wed Jun 24, 2020 20:46
Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. Herein, a semiconducting covalent organic framework (named NDA‐TN‐AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA‐TN‐AO with a high anti‐biofouling activity by generating biotoxic reactive oxygen species, and promoting photoelectrons...
Wed Jun 24, 2020 19:19
Hydrodesulphurization, the removal of sulphur from crude oils, is an essential catalytic process in the petroleum industry safeguarding the production of clean hydrocarbons. Sulphur removal is critical for the functionality of downstream processes and vital to the elimination of environmental pollutants. The effectiveness of such an endeavour is among other factors determined by the structural arrangement of the heterogeneous catalyst. Namely, the accessibility of the catalytically active molybdenum...
Wed Jun 24, 2020 19:13
We evaluated co‐assembling vaccines composed of lipidated HER2‐derived antigenic CH401 peptide and a lipophilic adjuvant, Pam 3 CSK 4 , α‐GalCer, or lipid A 506, as breast cancer vaccine candidates. This vaccine design was aimed to inherit both antigen multivalency and antigen‐specific immunostimulation properties, observed in reported self‐adjuvanting vaccine candidates, using self‐assembling and adjuvant‐conjugated antigens. Under vaccination concentrations, respective lipophilic adjuvants...
Wed Jun 24, 2020 18:14
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 perovskite oxide through gradient replacement of the B site with valence alternated element. The dual defects...
Wed Jun 24, 2020 18:14
Understanding and controlling multicomponent coassembly is of primary importance in different fields, such as materials fabrication, pharmaceutical polymorphism and supramolecular polymerization, but these aspects have been a long‐standing challenge. Herein, we discover that liquid‐liquid phase separation (LLPS) into ion cluster‐rich and ion cluster‐poor liquid phases is the first step prior to coassembly nucleation based on a model system of water‐soluble porphyrin and ionic liquids. The LLPS‐formed...
Wed Jun 24, 2020 17:44
Anion transporters have shown potential application as anti‐cancer agents that function by disrupting homeostasis and triggering cell death. In this research article we report switchable anion transport by gold complexes of anion transporters that are ‘switched on’ in situ in the presence of the reducing agent GSH by decomplexation of gold. GSH is found in higher concentrations in tumours than in healthy tissue and hence this approach offers a strategy to target these systems to tumours.
Wed Jun 24, 2020 16:45
Surface‐bound ligand molecules with suitable chemical and physical properties have been widely employed not only in nanocrystal synthesis where the size, morphology, phase structure, and even optoelectronic features can be defined, they have also been utilized in modulating the assembly behaviors of nanocrystals in terms of the packing modes, dimensions, as well as functionalities. Herein, we report a facile growth of 3‐dimensional CsPbBr 3 perovskite supercrystals (PSCs) self‐assembled from individual...
Wed Jun 24, 2020 12:59
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