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Epimerization/C-alkylation of a seven-membered iminosugar with a broad hexosaminidase inhibition spectrum leads to low micromolar HexAB and NagZ inhibitors.

Triarylboranes have been known for more than 100 years and have found potential applications in various fields such as anion sensors and optoelectronics, for example in organic light emitting diodes (OLEDs), field effect transistors (OFETs), and organic photovoltaic devices. However, biological applications, such as bioimaging agents and biomolecule sensors have evolved much more recently. This review summarises progress in this relatively young field and highlights the potential of triarylboranes in biological applications.

Diagram depicting the strategy for fabricating DNA-based hydrogels impregnated by ultrathin 2D tungsten disulfide nanosheets relevant for biomedical applications.

The application of azimuthal plot analysis of tts-μXRD results allows us to discriminate the origin of calcium oxalate nephrolith formation.

Plasmonic-based reticular materials are promising photocatalysts for CO2 reduction due to their efficient charge separation, band structure and crystalline properties.

A series of 6-oxo verdazyl radicals functionalised at the 1- and 5-positions by methyl, thiomethyl and iodo groups were synthesised using conventional strategies. Facile Sonogashira cross-coupling reactions of terminal alkynes with the diiodo analogue were used for synthetic elaboration of the verdazyl core structure with π-conjugated ethynyl groups. The radicals were characterised by EPR spectroscopy, single-crystal X-ray diffraction, cyclic voltammetry and optical spectroscopy. The chemically and electrochemically reversible oxidation and reduction of these radicals within a convenient redox window permitted further studies on the closed-shell cationic and anionic forms using spectroelectrochemical methods, supported by (TD-)DFT calculations.

The catalysis of the Hajos–Parrish reaction bycis- andtrans-4,5-ethano-proline was explored experimentally and computationally with DFT (ωB97X-D and MN15) and DLPNO-CCSD(T).

Broadband photodetectors (PDs) have great applications in both industrial and scientific sectors. In this study, solution-processed broadband PDs with an “inverted” vertical photodiode device structure without incorporating transparent conductive oxides electrodes, fabricated by bulk heterojunction (BHJ) composites composed of a low optical gap conjugated polymer blended with highly electrically conductive PbS quantum dots (QDs), operated at room temperature, are reported. The low optical gap conjugated polymer incorporated with PbS QDs contributes to the spectral response from the ultraviolet (UV)-visible to the infrared (IR) range. To realize the IR spectral response and to circumvent the weak IR transparency of the transparent oxide electrodes, the implementation of a photodiode with an “inverted” vertical device structure with the Au anode and the Ba/Al bilayer semitransparent cathode passivated with the MgF2 layer is demonstrated. Photoinduced charge carrier transfer occurring within the BHJ composite gave rise to decent photocurrent, resulting in detectivities greater than 1012 Jones (cm Hz1/2/W) over the wavelength from the UV-visible to the IR range under low applied bias. Thus, our findings of the utilization of the BHJ composites and an “inverted” vertical photodiode without the incorporation of the transparent conductive oxide electrodes provide a facile way to realize broadband PDs.

A breadth of strategies are needed to efficiently modify oligonucleotides with peptides or lipids to capitalize on their therapeutic and diagnostic potential, including the modulation of in vivo chemical stability and for applications in cell-targeting and cell-permeability. The chemical linkages typically used in peptide oligonucleotide conjugates (POCs) have limitations in terms of stability and/or ease of synthesis. Herein, we report an efficient method for POC synthesis using a diselenide-selenoester ligation (DSL)-deselenization strategy that rapidly generates a stable amide linkage between the two biomolecules. This conjugation strategy is underpinned by a novel selenide phosphoramidite building block that can be incorporated into an oligonucleotide by solid-phase synthesis to generate diselenide dimer molecules. These can be rapidly ligated with peptide selenoesters and, following in situ deselenization, leads to the efficient generation of POCs. The diselenide within the oligonucleotide also serves as a flexible functionalisation handle that can be leveraged for fluorescent labelling, as well as for alkylation to generate micelles.

International audience; Serendipitous self-assembly is a potential approach for achieving structurally versatile and unexpected solids with chosen metal–ligand combinations. Cyclen (1,4,7,10-tetraazacyclododecane) is an interesting flexible molecule, well explored for biological and material applications of its metal complexes. The dihedral angle (θ) between four nitrogen atoms of free cyclen is close to 0°. Still, it may vary upon complexation, allowing flexibility to adopt any two conformers, viz., (i) planar and (ii) twisted. The present work establishes the crucial role of metal ions in controlling the conformation adopted by cyclen through metal complexation. SCXRD studies of the complexes of cyclen with CuII and NiII with halides and pseudohalides as counterions reveal the existence of a planar conformation (θ = ∼0–3°) for cyclen in CuII systems and a highly twisted conformation (hitherto unreported) in NiII systems (θ = ∼52–55°). Further, SQUID magnetic studies for the dimeric [Ni1] complex reveal antiferromagnetic interactions between the two Ni centres.

A low-spin stabilized Fe(ii) spin-crossover material shows a single-step cooperative thermal transition and multi-stepped photoinduced high-spin – low-spin relaxation.

The intermetallic wetting between metallic liquids and solid surfaces enables a high-resolution liquid metal patterning strategy which is widely applicable for fabricating functional patterns on versatile substrates and planar/3D geometries.

Disulfide bonds are often employed as reductively cleavable sites in biomaterials and polymers. Here we demonstrate the aerobic photo-cross-linking of thiol-containing polymers through disulfide formation using a sensitizer and telluride catalyst.

The classic and most widely used co-reactant electrochemiluminescence (ECL) reaction of tris(2,2′-bipyridine)ruthenium(ii) ([Ru(bpy)3]2+) and tri-n-propylamine is enhanced by an order of magnitude by fac-[Ir(sppy)3]3− (where sppy = 5′-sulfo-2-phenylpyridinato-C2,N), through a novel ‘redox mediator’ pathway. Moreover, the concomitant green emission of [Ir(sppy)3]3−* enables internal standardisation of the co-reactant ECL of [Ru(bpy)3]2+. This can be applied using a digital camera as the photodetector by exploiting the ratio of R and B values of the RGB colour data, providing superior sensitivity and precision for the development of low-cost, portable ECL-based analytical devices., A water-soluble Ir(iii) complex is shown to enhance the ‘remote’ mechanism of the most widely used co-reactant ECL reaction of tris(2,2′-bipyridine)ruthenium(ii) with tripropylamine.

Most current biosensors were designed for the detection of individual analytes, or a group of chemically similar analytes. We reason that sensors designed to track both reactants and products might be useful for following chemical reactions. Adenosine triphosphate (ATP) is a key biomolecule that participates in various biochemical reactions, and its hydrolysis plays a fundamental role in life. ATP can be converted to adenosine diphosphate (ADP) and inorganic phosphate (Pi)

International audience; We report the reentrant phase transition of the organic-inorganic hybrid metal cluster (MC) compound (TBA)(2)[(Mo6Br8Br6a)-Br-i] (TBA = ((n-C4H9)(4)N)). Structural studies revealed that (TBA)(2)[(Mo6Br8Br6a)-Br-i] was crystallized in the conventional monoclinic phase with space group P2(1)/n. When the crystal was cooled down to 143 K, we observed a structural phase transition from the conventional phase to an unknown phase with packing structure similar to the conventional one; however, the unit cell was extended to a double size. A reentrant transition to the conventional structure was induced when the crystal was further cooled to 113 K. These reentrant phase transitions occurred without any symmetry changes caused by slight motions of the MCs and TBA(+) ions. Luminescence studies revealed that the phase transition poorly affected the emission spectra; however, the newly found phase exhibited 1.7 times longer emission lifetime than the conventional phase. These results indicate that MC-based compounds are promising and exhibit phase transitions and crystallographic polymorphisms.

DNA tweezers have emerged as powerful devices for a wide range of biochemical and sensing applications; however, most DNA tweezers consist of single units activated by DNA recognition, limiting their range of motion and ability to respond to complex stimuli. Herein, we present an extended, tripodal DNA nanotweezer with a small molecule junction. Simultaneous, asymmetric elongation of our molecular core is achieved using polymerase chain reaction (PCR) to produce length- and sequence-specific DNA arms with repeating DNA regions. When rigidified, our DNA tweezer can be addressed with streptavidin-binding ligands. Full control over the number, separation, and location of these ligands enables site-specific streptavidin recognition; all three arms of the DNA nanotweezer wrap around multiple streptavidin units simultaneously. Our approach combines the simplicity of DNA tile arrays with the size regime normally provided by DNA origami, offering an integrated platform for the use of branched DNA scaffolds as structural building blocks, protein sensors, and dynamic, stimuli-responsive materials., An extended, multivalent DNA nanotweezer that undergoes large-scale molecular motion upon protein recognition is presented. Our method based on “printing-elongation-folding” combines the DNA-minimal aspect of DNA tile-based assembly, with complexity of DNA origami.

DFT modelling predicts proximal boron groups can accelerate sulfenate alkylation reactions, depending on boron substituents and boron distance from the reaction site.

To address the increased demand for greater mechanical robustness of superhydrophobic and icephobic surfaces, we fabricated damage-tolerant, abrasion-insensitive, and icephobic superhydrophobic bulk nanocomposites using a facile, cost-effective, industrially applicable, and environmentally benign strategy. We prepared nanocomposites composed of high-temperature vulcanized silicone rubber through the highly controlled incorporation of nanosized fumed silica and microsized aluminum trihydrate particles. The produced nanocomposites did not require additional processing, such as sand abrasion or plasma treatment, to acquire their superhydrophobic properties. The extended roughness throughout the whole bulk of the nanocomposites imparted the volumetric superhydrophobicity and resistance to mechanical damage. The presence of micro-nanoparticles also enhanced the thermal stability and icephobic properties of the silicone rubber. The icephobic behavior of the developed nanocomposites was assessed based on freezing delay and push-off tests both of which denoted improved icephobic properties, i.e., high freezing delay time and low ice adhesion strength. We verified the extended duration of superhydrophobicity within the bulk nanocomposite using sandpaper abrasion, severe cutter scratching, tape peeling, and water-jet impacts. This study represents the first evaluation, to the best of our knowledge, of the icephobic properties of both the surface and bulk of the produced nanocomposite subjected to several cycles of sandpaper abrasion. Interestingly, even after multiple abrasion cycles, the samples demonstrated considerably low ice adhesion strength confirming their bulk icephobicity. In a nutshell, our findings are very promising for the fabrication of mechanically robust icephobic materials.

Herein we report a thiol-labile cysteine protecting group based on an unsaturated pyridazinedione (PD) scaffold. We establish compatibility of the PD in conventional solid phase peptide synthesis (SPPS), showcasing this in the on-resin synthesis of biologically relevant oxytocin. Furthermore, we establish the applicability of the PD protecting group towards both microwave-assisted SPPS and native chemical ligation (NCL) in a model system.

Asymmetric hydrogenation based on heterogeneous metal nanoparticles (NPs) has attracted extensive attention for the production of chiral chemicals due to its high conversion efficiency, simple product separation, and convenient catalyst regeneration. Nevertheless, its further practical application is still impeded by the leaching of expensive chiral ligands and by the associated extra purification costs that are caused by the weak absorption of the chiral ligands on the metal NPs. In contrast, chiral metal–organic frameworks (CMOFs) have been proposed to serve as metal NP supports and chirality inducers via biomimicry of the configuration of privileged natural cinchona alkaloids on the single-chiral-site level. Among the presented engineered isoreticular valine (Val)-, serine (Ser)-, and threonine (Thr)-derived CMOFs, the Thr-MOF-supported Pt nanoparticles (NPs) exhibit impressive enantioselectivity in the asymmetric hydrogenation of ethyl pyruvate (EP) in addition to inherently robust catalytic recyclability without the need to add either fresh chiral ligands or Pt NPs.

The study is carried out with the aim of establishing in which measure the outcomes of polyelectrolyte multilayer formation can be predicted on the basis of the results of complexation studies in solution and vice versa. For this purpose, the correlation between the process of complex and multilayer formation involving three pairs of vinylic polyions in solutions of binary 1:1 sodium salts (NaX ; X = F, Cl, Br, I, NO3, ClO4) was explored by means of dynamic and electrophoretic light scattering, potentiometry, microcalorimetry, spectrophotometry and quartz crystal microbalance. The gradual reactant mixing in solution at lower salt concentrations resulted in Fuoss-Sadek sequence of events (primary complexes → secondary complexes→1:1 flocculate)., whereby the obtained nano-complexes could be overcharged. At high salt concentration and excess polycation present, metastable nano-complexes and precipitates containing surplus of positively charged monomers were formed. The amount of extrinsically compensated charge was in accord with the polycation affinities toward counteranions, established by monitoring the electrolyte-induced aggregation of positively charged nano-complexes. Perfect analogy with respect to counteranion influence on the amount of adsorbed polycation was noticed for corresponding multilayers. Aside from providing the deeper understanding of interpolyelectrolyte neutralization, the gained insights can also be used to steer the polyelectrolyte multilayer composition and properties.

We present a versatile synthesis method capable of creating triphenylene discotic liquids with enhanced control of the number and type of tails. The compounds obtained from this method include a discotic liquid crystal with unusually short methoxy tails.

International audience; The isoelectronic doping of dichalcogenolato nanoclusters of the type [Ag-21{E2P(OR)(2)}(12)](+) (E = S, Se) by any heteroatom belonging to groups 9-12 was systematically investigated using DFT calculations. Although they can differ in their global structure, all of these species have the same M@M-12-centered icosahedral core. In any case, the different structure types are all very close in energy. In all of them, three different alloying sites can be identified (central, icosahedral, peripheral) and calculations allowed the trends in heteroatom site occupation preference across the group 9-12 family to be revealed. These trends are supported by complementary experimental results. They were rationalized on the basis of electronegativity, potential involvement in the bonding of valence d-orbitals and atom size. TD-DFT calculations showed that the effect of doping on optical properties is sizable and this should stimulate research on the modulation of luminescence properties in the dithiolato and diseleno families of complexes.

This study demonstrates enhancement of in-device electro-optic activity via a series of theory-inspired organic electro-optic (OEO) chromophores based on strong (diarylamino)phenyl electron donating moieties. These chromophores are tuned to minimize trade-offs between molecular hyperpolarizability and optical loss. Hyper-Rayleigh scattering (HRS) measurements demonstrate that these chromophores, herein described as BAH, show >2-fold improvement in β versus standard chromophores such as JRD1, and approach that of the recent BTP and BAY chromophore families. Electric field poled bulk devices of neat and binary BAH chromophores exhibited significantly enhanced EO coefficients (r33) and poling efficiencies (r33/Ep) compared with state-of-the-art chromophores such as JRD1. The neat BAH13 devices with charge blocking layers produced very large poling efficiencies of 11.6 ± 0.7 nm2 V−2 and maximum r33 value of 1100 ± 100 pm V−1 at 1310 nm on hafnium dioxide (HfO2). These results were comparable to that of our recently reported BAY1 but with much lower loss (extinction coefficient, k), and greatly exceeding that of other previously reported OEO compounds. 3 : 1 BAH-FD : BAH13 blends showed a poling efficiency of 6.7 ± 0.3 nm2 V−2 and an even greater reduction in k. 1 : 1 BAH-BB : BAH13 showed a higher poling efficiency of 8.4 ± 0.3 nm2 V−2, which is approximately a 2.5-fold enhancement in poling efficiency vs. JRD1. Neat BAH13 was evaluated in plasmonic–organic hybrid (POH) Mach–Zehnder modulators with a phase shifter length of 10 μm and slot widths of 80 and 105 nm. In-device BAH13 achieved a maximum r33 of 208 pm V−1 at 1550 nm, which is ∼1.7 times higher than JRD1 under equivalent conditions. ISSN:2051-6347 ISSN:2051-6355

Using metal–organic cages (MOCs) as preformed supermolecular building-blocks (SBBs) is a powerful strategy to design functional metal–organic frameworks (MOFs) with control over the pore architecture and connectivity. However, introducing chemical complexity into the network via this route is limited as most methodologies focus on only one type of MOC as the building-block. Herein we present the pairwise linking of MOCs as a design approach to introduce defined chemical complexity into porous materials. Our methodology exploits preferential Rh-aniline coordination and stoichiometric control to rationally link Cu4L4 and Rh4L4 MOCs into chemically complex, yet extremely well-defined crystalline solids. This strategy is expected to open up significant new possibilities to design bespoke multi-functional materials with atomistic control over the location and ordering of chemical functionalities., A new strategy to design atomically precise multivariate metal–organic frameworks is presented. This is achieved by linking two preformed metal–organic cages via a precisely tuned Rh–aniline interaction.

Thermoresponsive microgels undergo a volume phase transition from a swollen state under good solvent conditions to a collapsed state under poor solvent conditions. The most prominent examples of such responsive systems are based on poly-(N-isopropylacrylamide). When cross-linked with N,N′-methylenebisacrylamide, such microgels typically possess a fuzzy-spherelike morphology with a higher cross-linked core and a loosely cross-linked fuzzy shell. Despite the efforts devoted to understanding the internal structure of microgels and their kinetics during collapse/swelling, the origins of the accompanying changes in light scattering intensity have barely been addressed. In this work, we study core–shell microgels that contain small gold nanoparticle cores with microgel shells of different thicknesses and cross-linker densities. All microgels are small enough to fulfill the Rayleigh-Debye-Gans criterion at all stages of swelling. Due to the high X-ray contrast of the gold cores, we can use absolute intensity small-angle X-ray scattering to determine the number density in the dilute dispersions. This allows us to extract polymer volume fractions of the microgels at different stages of swelling from form factor analysis of small-angle neutron scattering data. We match our findings to results from temperature-dependent absorbance measurements. The increase in absorbance during the shrinkage of the microgels is related to the transition from fuzzy spheres to hard sphere-like scattering objects with a rather homogeneous density profile. We provide a first attempt to model experimental spectra using finite difference time domain simulations that take into account the structural changes during the volume phase transition. Our findings significantly contribute to the understanding of the optical properties of thermoresponsive microgels. Further, we provide polymer volume fractions and microgel refractive indices as a function of the swelling state.

Thionyl fluoride (SOF2) was first isolated in 1896, but there have been less than 10 subsequent reports of its use as a reagent for organic synthesis. This is partly due to a lack of facile, lab-scale methods for its generation. Herein we report a novel protocol for the ex situ generation of SOF2 and subsequent demonstration of its ability to access both aliphatic and aromatic acyl fluorides in 55–98% isolated yields under mild conditions and short reaction times. We further demonstrate its aptitude in amino acid couplings, with a one-pot, column-free strategy that affords the corresponding dipeptides in 65–97% isolated yields with minimal to no epimerization. The broad scope allows for a wide range of protecting groups and both natural and unnatural amino acids. Finally, we demonstrated that this new method can be used in sequential liquid phase peptide synthesis (LPPS) to afford tri-, tetra-, penta-, and decapeptides in 14–88% yields without the need for column chromatography. We also demonstrated that this new method is amenable to solid phase peptide synthesis (SPPS), affording di- and pentapeptides in 80–98% yields., Thionyl fluoride (SOF2) was developed as a rapid acid activation peptide coupling reagent for liquid phase peptide synthesis (LPPS) and solid phase peptide synthesis (SPPS).

The building blocks of life – nucleotides, amino acids and saccharides – give rise to a large variety of components and make up the hierarchical structures found in Nature. Driven by chirality and non-covalent interactions, helical and highly organised structures are formed and the way in which they fold correlates with specific recognition and hence function. A great amount of effort is being put into mimicking these highly specialised biosystems as biomaterials for biomedical applications, ranging from drug discovery to regenerative medicine. However, as well as lacking the complexity found in Nature, their bio-activity is sometimes low and hierarchical ordering is missing or underdeveloped. Moreover, small differences in folding in natural biomolecules (e.g., caused by mutations) can have a catastrophic effect on the function they perform. In order to develop biomaterials that are more efficient in interacting with biomolecules, such as proteins, DNA and cells, we speculate that incorporating order and handedness into biomaterial design is necessary. In this review, we first focus on order and handedness found in Nature in peptides, nucleotides and saccharides, followed by selected examples of synthetic biomimetic systems based on these components that aim to capture some aspects of these ordered features. Computational simulations are very helpful in predicting atomic orientation and molecular organisation, and can provide invaluable information on how to further improve on biomaterial designs. In the last part of the review, a critical perspective is provided along with considerations that can be implemented in next-generation biomaterial designs.

This work investigated the properties of a four-component molecular ensemble, in which a carbazole (CBz) donor and a benzothiadiazole (BTD) acceptor are connected through a phenylthiophene (PT) bridge. The multiple rotational freedoms at the C--C single bonds that interconnect the different arene units render this compound a molecular rotor that shows interesting intramolecular N●●●S contact and various intermolecular non-covalent interactions in the solid state. Detailed structural and crystal packing properties were elucidated by single crystal X-ray diffraction analysis in conjunction with Hirshfeld surface analysis and density functional theory (DFT) calculations. Cyclic voltammetric (CV) analysis indicated that this donor--acceptor ensemble exhibits electrochemical amphoteric redox behavior with a relatively narrow electronic bandgap (Eg) of 1.95 eV. Moreover, this CBz--PT--BTD molecular rotor was found to emit orange-to-red luminescence in different organic solvents. The solvatofluorochromic behavior was due to twisted intramolecular charge-transfer (TICT) emission and agreed well with the Lippert-Magata relationship. Moreover, the fluorescence efficiency of this molecular rotor showed dependence on solvent viscosity as well as other solvent parameters.

Rotational spectroscopy and quantum mechanical calculations reveal a significant change in conformational landscapes when oxygen is substituted with sulfur: observation of features from nine conformers of diallylether versus one of the sulfide.

Nanoelectrochemistry, where electrochemical processes are controlled and investigated with nanoscale resolution, is gaining more and more attention because of the many potential applications in energy and sensing and the fact that there is much to learn about fundamental electrochemical processes when we explore them at the nanoscale. The development of instrumental methods that can explore the heterogeneity of electrochemistry occurring across an electrode surface, monitoring single molecules or many single nanoparticles on a surface simultaneously, have been pivotal in giving us new insights into nanoscale electrochemistry. Equally important has been the ability to synthesise or fabricate nanoscale entities with a high degree of control that allows us to develop nanoscale devices. Central to the latter has been the incredible advances in nanomaterial synthesis where electrode materials with atomic control over electrochemically active sites can be achieved. After introducing nanoelectrochemistry, this paper focuses on recent developments in two major application areas of nanoelectrochemistry; electrocatalysis and using single entities in sensing. Discussion of the developments in these two application fields highlights some of the advances in the fundamental understanding of nanoelectrochemical systems really driving these applications forward. Looking into our nanocrystal ball, this paper then highlights: the need to understand the impact of nanoconfinement on electrochemical processes, the need to measure many single entities, the need to develop more sophisticated ways of treating the potentially large data sets from measuring such many single entities, the need for more new methods for characterising nanoelectrochemical systems as they operate and the need for material synthesis to become more reproducible as well as possess more nanoscale control.

International audience; We report the influence of positional isomerism on the electronic (electrochemical HOMO/LUMO energy levels), photophysical and physical properties (molecular organization, crystallinity and phase transitions) and charge transport properties of dispiroacridine-indacenobisthiophene positional isomers. The isomers differ from the central indacenobisthiophene (IDT) core, which displays either para or meta linkages. We show that the spiro-connected phenylacridine bridges have a significant influence on all these properties and particularly on the charge transport mobility values, which were found to be higher in the meta isomer than in the para isomer. This finding is different to what was reported in the literature for the other couples of IDT-based isomers and shows the key role played by the spiro-connected fragments in these molecular systems.

Thermal energy storage systems utilising phase change materials have the potential to overcome the intermittency issues associated with most renewable energy sources, significantly contributing to the decarbonisation of the energy sector. While the concept of storing energy in the latent heat of a phase transition is not new, large scale systems employing this concept have not yet realised their full potential. This is in large part due to the shortcomings of conventionally used materials – whether it be issues with their flammability, chemical and thermal instability, corrosivity, poor cycling stability, or a combination of these. Ionic liquids offer a suite of inherent “green” properties that translate well into the field of phase change materials, namely low volatility, low flammability, and good thermal and chemical stability, alongside the potential to tune their chemical and phase properties. In this Perspective, we discuss the evolution and promise of the emerging field of ionic liquids for renewable thermal energy storage. Systems are considered from a holistic, sustainable point of view, demonstrating the importance of assessing material origins and synthetic pathways as well as system performance through lifecycle assessment. We elucidate the emerging design rules for optimising thermal properties, and in doing so attempt to provide an overview of promising emerging systems and future directions.

This article provides a review of various types of self-rechargeable batteries powered by ubiquitous clean and sustainable energy sources.

Embedding Ag single atoms onto densely arrayed Cu nanopyramids could optimize the *CO adsorption strength toward direct propanediol production via a one-step concerted *CO trimerization mechanism.

Amphiphilic Janus dendrimers with aggregation-induced emission property undergo self-assembly to yield emissive dendrimersomes of tunable sizes and quantum yields.

Hydrogen evolution from electrochemical water splitting under alkaline conditions is an ongoing challenge for the requirement of a simultaneous balance to be achieved between the water dissociation step and the hydrogen adsorption on the catalysts. Herein, Bi2O3, an inactive catalyst for hydrogen evolution reaction (HER) aroused by its unfavourable hydrogen adsorption Gibbs free energy (ΔGH*), is activated by an in-situ phase engineering strategy for efficient HER electrocatalysis in alkaline media. Via this strategy, two-dimensional (2D) dual active Bi2O3 nanosheets with both BixNi alloy phases and α-Bi2O3 were fabricated to simultaneously catalyse the water dissociation step and the hydrogen formation step during the alkaline HER. In combining with the advantages of 2D nanomaterials and dual active catalytic sites, this phase engineered Bi2O3-based catalyst exhibited simultaneously accelerated water dissociation and optimized ΔGH* and thus excellent HER performance. The modulated catalyst demonstrated an overpotential of 127 mV (at j = 10 mA cm-2) and a Tafel slope of 92 mV dec-1 in 1 M KOH, which is exceptional compared with other Bi2O3-based HER electrocatalysts. This work not only provides an innovative way to activate HER-inferior bismuth oxide-based catalysts, but also offers new insights into the design of dual active catalysts for sluggish alkaline HER catalysis.

Electrolyte buffering species have been shown to act as proton donors in the hydrogen evolution reaction (HER). Analogously, we study here whether these electrolyte species may participate in other reactions by investigating CO electrooxidation (COOR) on a gold rotating disk electrode. This model system, characterized by fast kinetics, exhibits a dffusion-limited regime, which helps in the identification of the species dictating the diffusion-limited current. Through a systematic concentration dependence study in a variety of buffers, we show that electrolyte buffering species act as oxygen donor shuttles in COOR, lowering the reaction overpotential. A similar correlation between electrolyte and electrocatalytic activity was observed for COOR on a different electrode material (Pt). Probing the electrode-electrolyte interface by attenuated total reflection infrared spectroscopy (ATR-FTIR) and modelling the surface speciation to include the effect of the solution reactions, we propose that the buffer conjugated base generates the oxygen donor (i.e. OH-) through its acid-base reaction with water.

We demonstrate extraordinarily spectrally selective narrowband mid-infrared radiation via coupling of plasmon resonance and molecular vibration. Absorbance and thermal emittance with resonant peak FWHM ≤ 124 nm at λ = 5.73 μm, corresponding to a Q-factor of ∼92.3 were obtained.

In this Frontier article, recently discovered chromium(0) and manganese(I) complexes emitting from metal-to-ligand charge transfer (MLCT) excited states are highlighted. Chelating isocyanide ligands give access to this new class of 3d6 emitters with MLCT lifetimes in (or close to) the nanosecond regime in solution at room temperature. Although the so far achievable luminescence quantum yields in these open-shell complexes are yet comparatively low, the photophysical properties of the new chromium(0) and manganese(I) isocyanides are reminiscent of those of well-known ruthenium(II) polypyridines. Our findings provide insight into how undesired nonradiative MLCT deactivation in 3d6 complexes can be counteracted, and they seem therefore relevant for the further development of new luminescent first-row transition metal complexes based on iron(II) and cobalt(III) in addition to chromium(0) and manganese(I).

A hybrid material (SL–PPN–HEP–HRP) of dual enzyme function was prepared by co-immobilization of papain (PPN) and horseradish peroxidase (HRP) on sulphate latex (SL) microspheres using heparin (HEP) polyelectrolyte as a building block in the sequential adsorption method. The doses of PPN, HEP and HRP were optimized in each step of the preparation process to achieve high functional and colloidal stability. The enzymes and the polyelectrolyte strongly adsorbed on the oppositely charged surfaces via electrostatic forces, and enzyme leakage was not observed from the hybrid material, as confirmed by colorimetric protein tests and microscopy measurements. It was found that the polyelectrolyte acted as a separator between PPN and HRP to prevent hydrolytic attack on the latter enzyme, which otherwise prevents the joint use of these important biocatalysts. Excellent colloidal stability was obtained for the SL–PPN–HEP–HRP composite and the embedded PPN and HRP showed remarkable protease and peroxidase activities, respectively, at least until five days after preparation. The present results offer a promising approach to develop biocatalytic systems of dual function, which are often required in manufacturing processes in the food industry, where the colloidal stability of such multifunctional materials is a key parameter to achieve remarkable efficiency.

Metal-organic layers (MOLs) are of great interest in heterogeneous catalysis, particularly materials that can accommodate extraneous metal centres. Here, we demonstrate a two-step preorganisation/delamination synthetic strategy using CuI as a template to prepare Zr-based MOLs with accessible 'syn' bis-pyrazolyl chelating sites (named

Novel carbon based “X-type” graphene nanoribbons (GNRs) with azulenes were designed for applications in nonlinear optics in the present work, and the second order nonlinear optical (NLO) properties of those X-type GNRs were predicted using the sum-over-states (SOS) model. The GNRs with edge states are feasibly polarized. The effects of zigzag edges on the NLO properties of GNRs are scrutinized by passivation, and the electronic structures of GNRs are modulated with heteroatoms at the zigzag edges for improved stability and NLO properties. Those nanomaterials were further functionalized with electron-donating and electron-withdrawing groups (NH2/NO2) to enhance the NLO responses, and the connection of those functional groups at the azulene ends play a determinant role in the enhancement of the NLO properties of those X-type nanoribbons, e.g., the static first hyperpolarizability (〈β0〉) changes from −783.23 × 10−30 esu to −1421.98 × 10−30 esu. The mechanism of such an enhancement has been investigated. Through two-dimensional second order NLO spectra simulations, particularly besides the strong electro-optical Pockels effect and optical rectification responses, strong electronic sum frequency generations and difference frequency generations are observed in those GNRs. The strong second order NLO responses of those GNRs in the visible light region bring about potential applications of these carbon nanomaterials in nonlinear nanophotonic devices and biological nonlinear optics.

The oxygen evolution reaction (OER) is the bottleneck reaction of water splitting, which can be used to generate green hydrogen from renewable electricity. Cobalt iron oxyhydroxides (CoFeOxHy) are among the most active OER catalysts in alkaline medium. However, the active sites of these catalysts remain unclear. Here we use operando ultraviolet-visible (UV-Vis), X-ray absorption, and Raman spectroscopy to reveal oxidations of both Fe and Co ions in CoFeOxHy during the OER. By analyzing samples with different Fe contents and thickness, we find that the concentration of Fe4+ species at the surface, but not the concentration of Co4+ in the bulk, scales with the catalytic activity. These results indicate an Fe4+-containing active site in CoFeOxHy.

International audience; Induction time, a measure of how long one will wait for nucleation to occur, is an important parameter in quantifying nucleation kinetics and its underlying mechanisms. Due to the stochastic nature of nucleation, efficient methods for measuring large number of independent induction times are needed to ensure statistical reproducibility. In this work, we present a novel approach for measuring and analyzing induction times in sessile arrays of microdroplets via deliquescence/recrystallization cycling. With the help of a recently developed image analysis protocol, we show that the interfering diffusion-mediated interactions between microdroplets can be eliminated by controlling the relative humidity, thereby ensuring independent nucleation events. Moreover, possible influence of heterogeneities, impurities, and memory effect appear negligible as suggested by our 2-cycle experiment. Further statistical analysis (k-sample Anderson-Darling test) reveals that upon identifying possible outliers, the dimensionless induction times obtained from different datasets (microdroplet lines) obey the same distribution and thus can be pooled together to form a much larger dataset. The pooled dataset showed an excellent fit with the Weibull function, giving a mean supersaturation at nucleation of 1.61 and 1.85 for the 60pL and 4pL microdroplet respectively. This confirms the effect of confinement where smaller systems require higher supersaturations to nucleate. Both the experimental method and the data-treatment procedure presented herein offer promising routes in the study of fundamental aspects of nucleation kinetics, particularly confinement effects, and are adaptable to other salts, pharmaceuticals, or biological crystals of interest.

The dynamical complexity of the hydrogen-bonded water network can be investigated with intense Terahertz (THz) spectroscopy, which can drive the liquid into the nonlinear response regime and probe anharmonicity effects. Here we report single-color and polarization-dependent pump–probe experiments at 12.3 THz on liquid water, exciting the librational mode. By comparing results obtained on a static sample and a free-flowing water jet, we are able to disentangle the distinct contributions by thermal, acoustic, and nonlinear optical effects. We show that the transient transmission by the static water layer on a time scale of hundreds of microseconds can be described by thermal (slow) and acoustic (temperature-dependent) effects. In addition, during pump probe overlap we observe an anisotropic nonlinear optical response. This nonlinear signal is more prominent in the liquid jet than in the static cell, where temperature and density perturbations are more pronounced. Our measurements confirm that the THz excitation resonates with the rotationally-damped motion of water molecules, resulting in enhanced transient anisotropy. This model can be used to explain the non-linear response of water in the frequency range between about 1 and 20 THz.

Human body is continuously in a never-ending chess game against pathogens. When the immune system, our natural defense tool, is weakened, these organisms are able to escape, collapsing the body contingency plan, which results in a pathological state. To overcome this checkmate status, emerging nanomedicines have been successfully employed as one of the best booming tactic for the immune response, manipulating the body defense tools for a specific recognition/elimination of pathological cells via active ingredient delivery. However, the vast majority of these drug delivery systems (DDS) has been often considered exclusively as passive vehicles. Among them, nanoscaled metal-organic frameworks (nanoMOFs) have attracted a great attention due to their versatility, allowing to carry and deliver exceptional drug payloads and to modulate their biological bypass. Nonetheless, their intrinsic immunogenicity character has been never addressed. Considering the immense possibilities that nanoMOFs offer as treatment platform, our purpose is unveiling the MOF immunological fingerprint, including an in-deep evaluation of the cellular oxidation balance, the inflammation & recruitment of immune cells and the precise Th1/Th2 cytokine profile triggered. This performance will make more feasible the design of customized immune-active MOF nanoplatforms according to targeted diseases, becoming the next ace up of the immune system sleeve.

A pair of thermally activated delayed fluorescence (TADF) emitters with symmetric and asymmetric D-A-D structure are investigated. Despite displaying near-identical photoluminescence spectrum and quantum yields, the symmetric material possesses significantly better delayed fluorescence characteristics and OLED performance. Building on a previous study of analogous D-A materials we are able to explain these differences in terms of different strengths of electronic interactions between the two donor units. This interaction lowers the energy of the TADF-active triplet state in the asymmetric molecule, increasing its singlet–triplet energy gap and leading to worse performance. This result therefore demonstrates a new strategy to selectively control the triplet states of TADF molecules, in contrast to established control of singlet states using host environment. These results also show that multi-donor TADF emitters cannot be understood simply as the sum of their isolated parts; these parts have different electronic interactions depending on their relative positions, even when there is no scope for steric interaction.

Solid-state batteries (SSBs) have attracted considerable attention due to the high intrinsic stability and theoretical energy density. As the core part, garnet electrolyte has been extensively investigated due to high lithium-ion conductivity, wide electrochemical potential window, and easy synthesis. However, the poor and electrochemically unstable interfacial contact between electrolyte and lithium anode greatly impedes the practical use of garnet based SSBs. Here, we report such interface challenge can be perfectly tackled by introducing a multifunctional Li0.3La0.5TiO3 (LLTO) as additive into lithium anode. The limited reaction between the LLTO and lithium effectively changes the physical properties of lithium anode, making it perfectly compatible with garnet surface, consequently significantly decreasing the interfacial resistant from 200 to only 48 Ω cm2 and greatly improving the interface stability and avoiding the dendrite formation. Interestingly, LLTO provides additional lithium storage, and the close interface contact and the high lithium-ion conductivity of LLTO ensures high-rate performance. Consequently, the symmetrical cell runs stably at 0.1 mA cm-2 for 400 h without obvious degradation. The assembled SSB with the LiFePO4 cathode and Li-LLTO composite anode demonstrates a specific capacity of 147 mAh g-1 and remarkable cycling stability with only 10 % capacity decay over 700 cycles at 1 C.