Cover Picture: Recoding the Genetic Code with Selenocysteine (Angew. Chem. Int. Ed. 1/2014)

Editable Supercapacitors with Customizable Stretchability Based on Mechanically Strengthened Ultralong MnO2 Nanowire Composite

Although some progress has been made on stretchable supercapacitors, traditional stretchable supercapacitors fabricated by predesigning structured electrodes for device assembling still lack the device-level editability and programmability. To adapt to wearable electronics with arbitrary configurations, it is highly desirable to develop editable supercapacitors that can be directly transferred into desirable shapes and stretchability. In this work, editable supercapacitors for customizable shapes and stretchability using electrodes based on mechanically strengthened ultralong MnO₂ nanowire composites are developed. A supercapacitor edited with honeycomb-like structure shows a specific capacitance of 227.2 mF cm^-2 and can be stretched up to 500% without degradation of electrochemical performance, which is superior to most of the state-of-the-art stretchable supercapacitors. In addition, it maintains nearly 98% of the initial capacitance after 10 000 stretch-and-release cycles under 400% tensile strain. As a representative of concept for system integration, the editable supercapacitors are integrated with a strain sensor, and the system exhibits a stable sensing performance even under arm swing. Being highly stretchable, easily programmable, as well as connectable in series and parallel, an editable supercapacitor with customizable stretchability is promising to produce stylish energy storage devices to power various portable, stretchable, and wearable devices.

A new redox-based and stepwise synthetic strategy lead to an unprecedented mixed-valence Keggin-type tungstovanadophosphate (WVI/VIV) bi-capped by vanadium(VIII)-complexes

A new POM-based V^III-organic coordination compound has been prepared using a redox-based and stepwise synthetic strategy.

Area negative thermal expansion in a mixed metal mixed organic MOF: “elevator-platform” mechanism induced by O–H⋯O hydrogen bonding

Rare area negative thermal expansion of a new mixed metal mixed organic MOF has been described using an “elevator-platform” analogy induced by O–H⋯O hydrogen bonding.

Asperones A–E, five dimeric polyketides with new carbon skeletons from the fungus Aspergillus sp. AWG 1–15

Five dimeric polyketides with two novel skeletons, generated by the crucial [3 + 2] and [3 + 3] cycloadditions, were isolated from Aspergillus sp.

Two interpenetrated metal–organic frameworks with a slim ethynyl-based ligand: designed for selective gas adsorption and structural tuning

Structural tuning and selective gas adsorption of two interpenetrated metal–organic frameworks using a slim ethynyl-based ligand were achieved.

Hierarchical heterostructure of Ag-nanoparticle decorated fullerene nanorods (Ag–FNRs) as an effective single particle freestanding SERS substrate

A hierarchical heterostructure composed of silver nanoparticles on fullerene nanorods functions as SERS substrate for the detection Rhodamine 6G: R6G in nanomolar concentration range.

Simple preparation and highly selective detection of silver ions using an electrochemical sensor based on sulfur-doped graphene and a 3,3′,5,5′-tetramethylbenzidine composite modified electrode

An electrochemical sensor based on S-Gr-TMB/GCE was prepared to solve the nonselectivity problem of TMB as a spectral probe.

Stereochemical effects on dynamics in two-component systems of gelators with perfluoroalkyl and alkyl chains as revealed by vibrational circular dichroism

The VCD method was applied to the gelation processes of chiral two-component gel systems.

Total synthesis of natural productsviairidium catalysis

An overview of the highlights in total synthesis of natural products using iridium as a catalyst is given.

Zeolitic-imidazolate-framework (ZIF-8)/PEDOT:PSS composite counter electrode for low cost and efficient dye-sensitized solar cells

ZIF-8 polystyrenesulfonate-doped poly(3,4-ethylenedioxythiophene) (ZIF-8/PEDOT:PSS) is prepared and used as the alternative counter electrode (CE) for dye-sensitized solar cells (DSSCs) based on I⁻/I₃⁻ and Co²⁺/Co³⁺ redox mediators.

Host–guest complexes of cucurbit[6]uril with phenethylamine-type stimulants

The macrocyclic host cucurbit[6]uril forms either partial inclusion or perching complexes with phenethylamine drugs ephedrine, synephrine and octopamine.

Supramolecular self-assembly for designing non-centrosymmetric crystals based on Keggin polyoxometallates and crown ether

POM based non-centrosymmetric inorganic–organic hybrids are designed by gradually introducing asymmetry into the building units.

Active Sites Intercalated Ultrathin Carbon Sheath on Nanowire Arrays as Integrated Core-Shell Architecture: Highly Efficient and Durable Electrocatalysts for Overall Water Splitting

The development of active bifunctional electrocatalysts with low cost and earth-abundance toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) remains a great challenge for overall water splitting. Herein, metallic Ni₄ Mo nanoalloys are firstly implanted on the surface of NiMoO_x nanowires array (NiMo/NiMoO_x ) as metal/metal oxides hybrid. Inspired by the superiority of carbon conductivity, an ultrathin nitrogen-doped carbon sheath intercalated NiMo/NiMoO_x (NC/NiMo/NiMoO_x ) nanowires as integrated core-shell architecture are constructed. The integrated NC/NiMo/NiMoO_x array exhibits an overpotential of 29 mV at 10 mA cm^-2 and a low Tafel slope of 46 mV dec^-1 for HER due to the abundant active sites, fast electron transport, low charge-transfer resistance, unique architectural structure and synergistic effect of carbon sheath, nanoalloys, and oxides. Moreover, as OER catalysts, the NC/NiMo/NiMoO_x hybrids require an overpotential of 284 mV at 10 mA cm^-2 . More importantly, the NC/NiMo/NiMoO_x array as a highly active and stable electrocatalyst approaches ≈10 mA cm^-2 at a voltage of 1.57 V, opening an avenue to the rational design and fabrication of the promising electrode materials with architecture structures toward the electrochemical energy storage and conversion.

Recent advances in studying single bacteria and biofilm mechanics

Bacterial biofilms correspond to surface-associated bacterial communities embedded in hydrogel-like matrix, in which high cell density, reduced diffusion and physico-chemical heterogeneity play a protective role and induce novel behaviors. In this review, we present recent advances on the understanding of how bacterial mechanical properties, from single cell to high-cell density community, determine biofilm tri-dimensional growth and eventual dispersion and we attempt to draw a parallel between these properties and the mechanical properties of other well-studied hydrogels and living systems.

Synthesis and electronic properties of ester substituted 1,4-dicyanodibenzodioxins and evaluation of anti-proliferative activity of all isomeric 1,2-, 2,3- and 1,4-dicyanodibenzodioxins against HeLa cell line

1,4-Dicyanodibenzodioxins bearing carboxy methyl ester groups were synthesized using our established one-step SNAr coupling reaction between ortho- and meta-ester substituted catechols and perfluorinated terephthalonitrile. These are the first examples of 1,4-dicyanodibenzodioxins substituted at both the benzene moieties. Optical spectra were similar to the earlier examples reported, with a marginal blue shift for the ester dibenzodioxins. Theoretical analysis of the molecular orbitals reveals modest destabilization of the frontier molecular orbitals of one carboxy methyl ester isomer over the other and overall higher HOMO-LUMO gap for both isomers when compared to the earlier published 1,4-dicyanodibenzodioxins. In vitro cytotoxicity against human cervical cancer HeLa cell line was evaluated for these two compounds and all other previously published dibenzodioxins from our laboratory (1,4-dicyano, 1,2-dicyano and 2,3-dicyano variants). A number of derivatives showed anti-tumor activity in μM ranges and also exhibited no cytotoxicity against normal HEK 293 cell line. Mechanistic investigation of cell death pathways indicated high levels of reactive oxygen species (ROS) in the dibenzodioxin treated tumor cell lines along with cellular nuclear fragmentation, both of which are markers of the apoptotic cell death pathway.

Phase transition and in situ construction of lateral heterostructure of 2D superconducting α/β Mo2C with sharp interface by electron beam irradiation

Lateral heterostructures of 2D materials have several interesting properties and potential applications, and they are usually fabricated by chemical vapor deposition. However, it still remains a great challenge to fabricate 2D lateral heterostructures with well-controlled patterns and sharp interfaces. Herein, we found that the 2D α-Mo₂C crystal, a recently emerging 2D superconductor, experiences a phase transition from the α phase to β phase on electron beam irradiation in a transmission electron microscope because of the migration of carbon atoms among the molybdenum octahedrons. Combined with first-principles calculations, the carbon atom migration paths and the corresponding energy barriers were discussed. Utilizing this unique phase transition property of 2D α-Mo₂C crystal, we demonstrated the precise in situ construction of the lateral heterostructure of 2D superconducting α/β Mo₂C with a well-controlled pattern and sharp interface using advanced aberration-corrected scanning transmission electron microscopy.

Luminescent manganese-doped CsPbCl3 perovskite quantum dots

Nanocrystalline cesium lead halide perovskites (CsPbX₃, X = Cl, Br, and I) form an exciting new class of semiconductor materials showing quantum confinement. The emission color can be tuned over the full visible spectral region making them promising for light‒emitting applications. Further control over the optical and magnetic properties of quantum dots (QDs) can be achieved through doping of transition metal (TM) ions such as Mn²⁺ or Co²⁺. Here we demonstrate how, following QD synthesis in the presence of a Mn‒precursor, dropwise addition of silicon tetrachloride (SiCl₄) to the QDs in toluene results in the formation of Mn‒doped CsPbCl₃ QDs showing bright orange Mn²⁺ emission around 600 nm. Evidence for successful doping is provided by excitation spectra of the Mn²⁺ emission, with all features of the CsPbCl₃ QD absorption spectrum and a decrease of the 410 nm excitonic emission life time with increasing Mn‒concentration, giving evidence for enhanced exciton to Mn²⁺ energy transfer. As a doping mechanism we propose a combination of surface etching and reconstruction and diffusion doping. The presently reported approach provides a promising avenue for doping TM ions into perovskites QDs enabling a wider control over optical and magnetic properties for this new class of QDs.

Fast Collisional Lipid Transfer Among Polymer-Bounded Nanodiscs

Some styrene/maleic acid (SMA) copolymers solubilise membrane lipids and proteins to form polymer-bounded nanodiscs termed SMA/lipid particles (SMALPs). Although SMALPs preserve a lipid-bilayer core, they appear to be more dynamic than other membrane mimics. We used time-resolved Förster resonance energy transfer and small-angle neutron scattering to determine the kinetics and the mechanisms of phospholipid transfer among SMALPs. In contrast with vesicles or protein-bounded nanodiscs, SMALPs exchange lipids not only by monomer diffusion but also by fast collisional transfer. Under typical experimental conditions, lipid exchange occurs within seconds in the case of SMALPs but takes minutes to days in the other bilayer particles. The diffusional and second-order collisional exchange rate constants for SMALPs at 30 °C are kdif = 0.287 s-1 and kcol = 222 M-1s-1, respectively. Together with the fast kinetics, the observed invariability of the rate constants with probe hydrophobicity and the moderate activation enthalpy of ~70 kJ mol-1 imply that lipids exchange through a "hydrocarbon continuum" enabled by the flexible nature of the SMA belt surrounding the lipid-bilayer core. Owing to their fast lipid-exchange kinetics, SMALPs represent highly dynamic equilibrium rather than kinetically trapped membrane mimics, which has important implications for studying protein/lipid interactions in polymer-bounded nanodiscs.

Biomineralization: From Material Tactics to Biological Strategy

Biomineralization is an important tactic by which biological organisms produce hierarchically structured minerals with marvellous functions. Biomineralization studies typically focus on the mediation function of organic matrices on inorganic minerals, which helps scientists to design and synthesize bioinspired functional materials. However, the presence of inorganic minerals may also alter the native behaviours of organic matrices and even biological organisms. This progress report discusses the latest achievements relating to biomineralization mechanisms, the manufacturing of biomimetic materials and relevant applications in biological and biomedical fields. In particular, biomineralized vaccines and algae with improved thermostability and photosynthesis, respectively, demonstrate that biomineralization is a strategy for organism evolution via the rational design of organism-material complexes. The successful modification of biological systems using materials is based on the regulatory effect of inorganic materials on organic organisms, which is another aspect of biomineralization control. Unlike previous studies, this study integrates materials and biological science to achieve a more comprehensive view of the mechanisms and applications of biomineralization.

Fluorescence Enhancement on Large Area Self-Assembled Plasmonic-3D Photonic Crystals

Discontinuous plasmonic-3D photonic crystal hybrid structures are fabricated in order to evaluate the coupling effect of surface plasmon resonance and the photonic stop band. The nanostructures are prepared by silver sputtering deposition on top of hydrophobic 3D photonic crystals. The localized surface plasmon resonance of the nanostructure has a symbiotic relationship with the 3D photonic stop band, leading to highly tunable characteristics. Fluorescence enhancements of conjugated polymer and quantum dot based on these hybrid structures are studied. The maximum fluorescence enhancement for the conjugated polymer of poly(5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene) potassium salt by a factor of 87 is achieved as compared with that on a glass substrate due to the enhanced near-field from the discontinuous plasmonic structures, strong scattering effects from rough metal surface with photonic stop band, and accelerated decay rates from metal-coupled excited state of the fluorophore. It is demonstrated that the enhancement induced by the hybrid structures has a larger effective distance (optimum thickness ≈130 nm) than conventional plasmonic systems. It is expected that this approach has tremendous potential in the field of sensors, fluorescence-imaging, and optoelectronic applications.

Emerging of Inorganic Hole Transporting Materials For Perovskite Solar Cells

Hole transporting material (HTM) is a significant component to achieve the high performance perovskite solar cells (PSCs). Over the years, inorganic, organic and hybrid (organic-inorganic) material based HTMs have been developed and investigated successfully. Today, perovskite solar cells achieved the efficiency of 22.1 % with with 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine) 9,9-spirobifluorene (spiro-OMeTAD) as HTM. Nevertheless, synthesis and cost of organic HTMs is a major challenging issue and therefore alternative materials are required. From the past few years, inorganic HTMs showed large improvement in power conversion efficiency (PCE) and stability. Recently CuO_x reached the PCE of 19.0% with better stability. These developments affirms that inorganic HTMs are better alternativesto the organic HTMs for next generation PSCs. In this report, we mainly focussed on the recent advances of inorganic and hybrid HTMs for PSCs and highlighted the efficiency and stability of PSCs improved by changing metal oxides as HTMs. Consequently, we expect that energy levels of these inorganic HTMs matches very well with the valence band of perovskites and improved efficiency helps in future practical deployment of low cost PSCs.

Li6Zn3(BO3)4: a new zincoborate featuring vertex-, edge- and face-sharing LiO4tetrahedra and exhibiting reversible phase transitions

A new zincoborate, Li₆Zn₃(BO₃)₄, was prepared, which exhibits two reversible phase transitions and contains a face-sharing LiO₄configuration.

High performance multifunctional green Co3O4 spinel nanoparticles: photodegradation of textile dye effluents, catalytic hydrogenation of nitro-aromatics and antibacterial potential

The multifunctional catalytic activity of Co₃O₄ spinel nanoparticles, synthesized using Punica granatum (pomegranate) seed extract was evaluated for its multiple applications.

Amphiphilic silane modified multifunctional nanoparticles for ratiometric oxygen sensing

Precise detection of dissolved oxygen (DO) at the cellular level plays a pivotal role in the diagnosis of many diseases and intraoperative observation.

Confinement effect of monolayer MoS2 quantum dots on conjugated polyimide and promotion of solar-driven photocatalytic hydrogen generation

Monolayer MoS₂ quantum dot (MQD) confined polyimide demonstrates 360% enhancement in hydrogen production compared to Pt/PI under solar light.

CdIn2S4/g-C3N4 heterojunction photocatalysts: enhanced photocatalytic performance and charge transfer mechanism

CdIn₂S₄/g-C₃N₄ heterojunction with excellent photocatalytic activities have been synthesized. The enhanced photocatalytic performance might be ascribed to the efficient photoinduced charge transfer derived from the heterojunction structure.

Synergy of facet control and surface metalloid modification on hierarchical Pt–Ni nanoroses toward high electrocatalytic activity

We demonstrated a highly active nitrogen species-decorated Pt–Ni–N electrocatalyst with tunable architectures, facets, and catalytic performance.

A metal–organic framework as a “turn on” fluorescent sensor for aluminum ions

A new three-dimensional (3D) metal–organic framework exhibits high sensitivity and selectivity for Al³⁺ ions as a “turn on” fluorescent sensor.

Recent advances on supramolecular isomerism in metal organic frameworks

This review highlights selected examples of supramolecular isomerism in the area of metal organic frameworks and major factors of their formation are also discussed.

Eosin Y catalysed photoredox synthesis: a review

In recent years, photoredox catalysis using eosin Y has come to the fore front in organic chemistry as a powerful strategy for the activation of small molecules.

Two novel metal–organic coordination polymers based on ligand 1,4-diazabicyclo[2.2.2]octane N,N′-dioxide with phase transition, and ferroelectric and dielectric properties

The synthesis of two low-temperature structural phase transition compounds {[Ag₃(dabcodo)(NO₃)₃]·H₂O}n (1) and [Ca(Dabcodo)(H₂O)₄Cl₂]_n (2) are described. Compound 1 displayed ferroelectric–ferroelectric phase transition.

Palladium-catalyzed, unsymmetrical homocoupling of thiophenes via carbon–sulfur bond activation: a new avenue to homocoupling reactions

Introduction of an unprecedented pattern of reactivity, namely the C–N unsymmetrical homocoupling by joining the electrophilic and nucleophilic motifs of the substrate through transition-metal catalysis.

Graphene quantum dot incorporated perovskite films: passivating grain boundaries and facilitating electron extraction

GQDs at grain boundaries effectively bond to CH₃NH₃PbI₃ so as to passivate the hanging bonds and rapidly extract electrons from CH₃NH₃PbI₃.

Supramolecular helical nanofibers formed by an achiral monopyrrolotetrathiafulvalene derivative: water-triggered gelation and chiral evolution

An achiral MPTTF-based gelator could form left- and right-handed supramolecular assemblies in pure DMF, whereas it turned into an opaque gel with right-handed nanofibers after adding small amounts of water.

Adjusting the proportions of {0001} facets and high-index facets of ZnO hexagonal prisms and their photocatalytic activity

ZnO hexagonal prisms with different proportions of {0001} facets and high-index facets were synthesized by a hydrothermal method. The proportion of {0001} facets and high-index facets was controlled by changing the amount of PEG.

Hydrolytic depolymerization of corncob lignin in the view of a bio-based rigid polyurethane foam synthesis

Corncob lignin was efficiently depolymerized in an isopropanol–water mixture with NaOH as catalyst into bio-polyols with low molecular weight and suitable hydroxyl number in view of the preparation of a bio-based rigid polyurethane foam.