A Y₂Ti₂O₅S₂ oxysulfide photocatalyst that is activated and stabilized by Rh/Cr₂O₃ and IrO₂ co-catalysts achieves efficient photocatalytic overall water splitting when irradiated with 600 nm visible light. The band gap of Y₂Ti₂O₅S₂ is a narrow 1.9 eV because Y 3d contributes to the valence band maximum. This Highlight discusses this recent innovation in sulfide-based photocatalytic materials. Key: conduction (CB) and valence (VB) bands, hydrogen (HEC) and oxygen (OEC) evolution co-catalysts.

The highest resolution of drug delivery is achieved by targeting molecules to specific subcellular compartments through chemical modifications. This approach can lead to improved clinical efficacy and reduced side effects and to essential chemical probes for cell biology research.

Thermally stable and able: All-inorganic CsPbX₃ perovskites (X is halide) have attracted attention owing to their thermally stability for photovoltaic applications. This Review presents the various CsPbX₃ materials and the challenges as well as perspectives for the future development of CsPbX₃ solar cells.

Photosynthesis with soap: Surfactants consisting of dye molecules and a polyhydroxylated fullerene self-assemble into bilayer vesicles that mimic key functions of photosystems II and I. They can absorb photons of two different visible wavelengths, exchange excited charge carriers, and thus enable the conversion of CO₂ into formic acid.

Size matters: Coordination isomerism was exploited for the first time to control the morphology of a supramolecular polymer. These observations pave the way for novel stimuli-responsive materials and offer a new approach for size control in self-assembled systems.

One stone, four birds: Various 2-bromobiaryl derivatives undergo a smooth cyclolanthanation upon reaction with nBu₂LaCl⋅4 LiCl. The resulting cyclometalated lanthanum reagents are versatile intermediates for the facile preparation of valuable polyfunctional biaryl derivatives. X-ray absorption fine structure (XAFS) measurements rationalize the proposed structures of the involved organolanthanum species.

At the border: The relative surface propensity of hydrated proton and hydroxide at the D₂O–air interface in the presence of excess D₃O⁺/OD⁻ was determined by probing the stretching vibration of interfacial water with sum-frequency generation spectroscopy. The hydrated proton is found to be orders of magnitude more surface active than the hydroxide ion.

One way or the other: Experimental and computational studies provide insight into the selectivity-controlling factors in ruthenium-catalyzed C−H arylation and oxidative C−H/C−H functionalization.

(B)rush delivery: The efficient delivery of an active DNA-modifying enzyme to human stem cells through high-density cell penetrating peptide brush polymers is reported. Brush polymer formulations utilizing cell penetrating peptides could promote delivery of Cre recombinase, whereas oligopeptides alone or oligopeptides displayed on nanoparticles did not.

The electronic ground state of the weakly magnetic U^IV was studied in great detail for the simple structurally characterized [UF₆]²⁻ anion, combining X-ray absorption spectroscopy, magnetometry, and quantum-chemical calculations. The decomposition and quantification of the relatively large spin and orbital magnetic moments provide key information for an improved understanding of the complex electronic structures of actinide ions.

Zinc-stabilized palladium colloids with a size of about 2 nm are the key building units for bifunctional syngas-to-dimethyl ether catalysts with enhanced stability, longevity, and high dimethyl ether selectivity. The catalysts were characterized by combining high-pressure operando X-ray absorption spectroscopy and DFT calculations.

Nucleosomal allostery: Inspired by the binding of RAPTA-T on the nucleosome core, which triggers a cascade of allosteric modifications to allow auranofin to bind at a distant site, a hetero-bimetallic compound was designed that bridges the two sites and impacts the activity of nucleosomes.

Light pillars: Host–guest interactions of pillar[5]arene (P5)-capped silver nanoclusters (Ag₂₉(LA-P5)₁₂(TPP)₂ with alkylamines and quaternary ammonium guest molecules resulted in the modulation of optical properties of the NCs, including an extraordinary circa 2000-fold photoluminescence enhancement.

Au₂₄Cu₆(SPhtBu)₂₂ was synthesized. It is effective in the catalysis of the epoxide ring-opening reaction. Control experiments and DFT calculations revealed that the π conjugation among the Cu−S bonds played a pivotal role.

Thio-fusion: Benzothiophenes are accessed from non-prefunctionalized arenes in a one-pot sequence involving an interrupted Pummerer reaction, [3,3]-sigmatropic rearrangement, and cyclization. The process does not require metals, proceeds by twofold C−H functionalization, and can be used to achieve the straightforward π-extension of polyaromatic hydrocarbons.

Charging ahead: The development of anion–ion batteries is possible by combining the benefits of p-type organic redox-active materials and molecular engineering to tune their working potentials. The pairing of an aromatic diamine as the positive electrode with a zwitterionic bipyridinium carboxylate compound as the negative electrode resulted in the assembly of an all-organic anionic battery.

Light fantastic: By applying right (RCP) or left (LCP) circularly polarized light to racemic samples of 1,1′-bi-2-naphthol (BINOL) coated onto achiral glass substrates, preferential desorption of enantiomers can be achieved, thereby providing contamination-free enantioenrichment. There are no known mechanisms for this phenomenon, and a simplified phenomenological model suggests that the contribution of quantum mechanical processes should be revisited.

The canopy: Molybdenum alkylidyne complexes with triarylsilanolate ligands are privileged catalysts for alkyne metathesis, but tethering of the silyl groups seems to make things even better. Crystallographic data and a rare case study based on ⁹⁵Mo NMR spectroscopy provide insights into why that is so.

Reductive Functionalization: The transition-metal-free synthesis of tetrahydroisoquinolines that bear a quaternary center through a reductive hydroxymethylation process is reported. It is a simple and robust method using cheap and accessible reagents to prepare complex heterocyclic motifs.

Crystallographic charge density analysis of a strong N−Br⋅⋅⋅N halogen bond in a N-bromosuccinimide and 3,5-dimethylpyridine co-crystal (NBS-lut) reveals a partially covalent character. Comparisons with pure crystalline NBS and the covalent bond in a bis(3-methylpyridine)bromonium cation suggest that there is a continuum of interactions between the intermolecular “non-bonding” halogen bond and a three centre–two electron covalent bond.

Elastic supercaps: An agar/hydrophobically associated polyacrylamide (HPAAm) double network (DN) hydrogel and pure polypyrrole (PPy) film based all-polymer supercapacitor was fabricated. It is highly elastic and reversibly stretchable. This supercapacitor can be stretched and recovered for 1000 times with no obvious performance degradation and strain residue, exhibiting excellent elasticity at the device level.

An evolutionary idea: Organic molecules in zeolite synthesis switch the predominant mode of silicalite-1 growth between classical and nonclassical pathways by mediating the degree to which silica nanoparticle precursors undergo microstructural evolution.

Negative isn't always bad: Reduction of a porphyrin nanoring by the addition of 4 or 6 electrons was found to result in global (anti)aromaticity (see picture), as revealed by ¹H NMR spectroscopy and DFT calculations. Thus, the Hückel rules apply to huge macrocyclic anions, and the charge in these anions is fully delocalized.

Balancing act: The indeno[1,2-b]carbazole donor not only combines the characteristics of carbazole and fluorene, but also exhibits excellent thermal stability and high hole mobility as a result of the bulky planar structure. Hole-transporting materials based on this methoxy-free donor demonstrate a high efficiency and stability simultaneously, providing a promising strategy for developing efficient and stable perovskite-based solar cells.

Well-defined polyacetals are designed that readily degrade in aqueous environments through the use of enyne metathesis polymerization. This approach permits modular design of the monomer scaffolds, and post-polymerization functionalization with triazolinediones modulates the rate of hydrolytic degradation.

With a twist: 6-Methylenebicyclo[3.2.1]oct-1-en-3-one, a twisted and highly reactive enone, was prepared for the first time by elimination of its bromide precursor. Its reactions as a dienophile with several dienes in Diels–Alder reactions proceeded smoothly to provide tricyclic and tetracyclic adducts, which allowed short syntheses (10–11 steps) of four kurane diterpenoids including 11β-hydroxy-16-kaurene, 11α-hydroxy-16-kaurene, liangshanin G, and gesneroidin B.

The two faces of CN: Cyanide ligands are generally C-bound in transition-metal chemistry, but for Mg, an isocyanide structure was established. Based on experiment and theory, at 298 K, a Mg−NC/Mg−CN ratio of 95:5 is found. In the solid state and in solution, isomerization is facile with a low energy barrier.

Planarization-enhanced stability: Dibenzo[g,p]chrysene (DBC), a “closed” version of tetraphenylethene (4PE), was integrated into a 2D heteroporous imine covalent organic framework (COF). The resulting DBC-COF exhibited much better crystallinity and stability than its counterpart 4PE-COF, and is a promising host material for ionic conduction.

An electrochemical method was developed for arylation of electron-deficient arenes through reductive activation. Various electron-deficient arenes and aryldiazonium tetrafluoroborates were examined for the transformation within an undivided cell, furnishing the desired products with up to 92 % yield. Reduction of quinoxaline is a key step in the transformation.

For the demonstration of physical forces in biology, a general concept in supramolecular chemistry that focuses on chalcogen bonds is introduced to access the desired stable, evolvable mechanochemistry tools. The source of inspiration of their rational design is illustrated in freeze–thaw cycles in DMSO.

Finding X-rays: Single crystals of a lead-free hybrid double perovskite, (BA)₂CsAgBiBr₇ (BA⁺: n-Butylammonium), adopting a unique 2D multilayered quantum-confined motif, can serve as a potential X-ray detecting material. This promise stems from the large μτ product of 1.21×10⁻³ cm² V⁻¹, high bulk resistivity, low trap density, and efficient X-ray attenuation.

Escape from flatland: A dearomative strategy is reported based on combination of arenophile chemistry and Pd catalysis. Non-activated arenes were readily converted into the corresponding syn-1,4-oxyaminated products using oximes or benzyl alcohols as O-nucleophiles. This process delivers products with an exclusive diastereoselectivity, amenable to myriad of further elaborations.

Interaction skills: Chiral nitrogen-containing compounds have been synthesized with excellent enantioselectivity (95–98 % ee) and high productivity (up to 2000 TON) by the Co-catalyzed asymmetric hydrogenation of C=N bonds. The reaction is facilitated by coordination of an NHBz group in the substrates to the cobalt atom and a nonbonding interaction with the ligand.

Amorphous NiFeMo oxide (up to 515 g one batch) with homogeneous elemental distribution was synthesized through a facile supersaturated co-precipitation method. The amorphous NiFeMo oxide undergoes rapid surface self-reconstruction during OER that forms a metal oxy(hydroxide) active layer with oxygen vacancies, enabling efficient OER catalysis.

Indane formation: A one-step organic catalytic strategy for enantioselective access to indanes with an all-carbon quaternary center is disclosed. The reaction involves an N-heterocyclic carbene (NHC) catalyzed process for direct arene construction, indane formation, remote-carbon desymmetrization, and excellent chirality control. This approach enables the concise synthesis of arene-containing molecules, including those having complex structures and challenging chiral centers.

Burst catalysis: A substrate-induced transient helical morphology was accessed as a self-assembled state. Critically, burst hydrolytic rates of substrates result in disassembly, thus mimicking the dynamic instability of microtubules.

Hooked! An approach to prepare supramolecular polymers by hooking together sigmoidal monomers into 1D arrays of π-stacked anthracene and acridine units is presented. It gives rise to micrometer-sized fibrils that show pseudoconductivities, in line with other conducting materials.

Making molecular triangles: The [3]triangulene ring system is easily accessed through a superacid-catalyzed cascade cyclization of benzyl cations followed by reduction of the planar 4,8,12-trihydrotriangulenium ion. Preliminary experiments support rapid oligomerization of triangulene in solution.

Protection at the nano-level: Molecular layer deposition is employed to fabricate a nanoscale “zircone” coating that is highly effective at stabilizing the Li metal anode interface. In-situ XAS is used for the first time to study the lithiation process of the artificial coating and the protected Li metal anode shows significantly enhanced cycling stability and lifetime in Li-O₂ batteries.

One, two, three! A three-component radical cascade for the enantioselective synthesis of γ-amino-acid derivatives is presented. The reactions proceed by redox and phosphoric acid dual catalysis, and work with readily available starting materials.

An unconventional nickel-catalyzed reaction has been developed for the synthesis of multifunctionalized benzofurans through the aryl nickelation of alkynes. A nucleophilic vinyl Ni^II species, from regioselective syn-aryl nickelation of an alkyne, undergoes an intramolecular cyclization with phenol ester to yield highly functionalized 1,1-disubstituted alkenes with 3-benzofuranyl and (hetero)aryl substituents.

One to three: An unprecedented stereoselective synthesis of trisubstituted vinylboronates from the transition-metal-free borylation of lithium ketone enolates was developed. Carbonyl-induced 1,3-metalate rearrangement through a C-bound boron enolate leads to the stereospecific C−O borylation of lithium enolates. A variety of stereospecific tri- and tetrasubstituted vinylboronates were easily obtained.

P-ylides: The use of Rh catalysis in the enantioselective ring-opening/cyclopropanation reactions of various P-ylides is demonstrated. This asymmetric reaction occurs through the cleavage of two bridgehead C−O bonds and the formation of two C−C bonds and constitutes the first highly enantioselective direct catalytic asymmetric cyclopropanation of stabilized P-ylide nucleophiles.

About the axis: The first organocatalytic atroposelective three-component cascade heteroannulation of 2,3-diketoesters, aromatic amines, and 1,3-cyclohexanediones has been developed. A wide range of axially chiral N-arylindoles were obtained in high yields and ee values by using a spirocyclic phosphoric acid catalyst. DCM=dichloromethane.

The selective one-electron reduction of nontrigonal R₃E compounds (E=P, As, Sb) afforded the first stable tricoordinate pnictogen-centered radical anion salts; the pnictogen atoms retain a planar T-shaped structure. EPR spectroscopy and calculations reveal that the spin density mainly resides at the p orbital of the pnictogen atom, which is perpendicular to the N₃E plane.

Ligands for nanocatalysts: Polymeric N-heterocyclic carbene (NHC) ligands are demonstrated to stabilize Au and Pd nanoparticles for CO₂ electroreduction while simultaneously enhancing their selectivity over competitive proton reduction.

A dendrite-free zinc plating behavior was achieved by combining a Cu-Zn solid solution interface on a copper mesh skeleton and polyacrylamide electrolyte additive. The zinc ion has strong selective adsorption on the acyl group of polyacrylamide and can be transferred along the polymer chains, leading to the homogeneous zinc distribution.

The unique dynamic oxygen-bubble template (DOBT) programmably controlled by a square-wave potential was utilized to tune catalyst morphology and expose Pt active facets in PtNi PFs. PtNi PFs with enriched Pt(111) facets can be obtained by affecting the surface-adsorbed OH^* through adjusting the anodic voltage.

By design: Novel lithium nickel borides with unique layered structures were theoretically predicted and synthesized. Their structures are composed of [NiB] layers with different topologies alternating with layers of Li cations (see picture). These compounds are ultimate precursors for further exfoliation to generate 2D transition-metal borides, known as MBenes.

Well-coordinated: Ordered mesoporous Ti³⁺-doped Li₄Ti₅O₁₂ nanocrystal frameworks were synthesized by the stoichiometric cationic coordination assembly process.

Unusual phase tester: An accessible pentapeptide system for studying gel–crystal phase transitions in supramolecular gels is introduced. The system allows to continuously measure the kinetics and visualize the dynamics of this common gel-destabilizing phase-transition process in situ using non-destructive microscopy-based methodology.

Light-induced protein labeling: Cyclopropenone-caged dibenzoannulated bicyclononynes (photo-DMBO) are photo-activatable dienophiles that engage in rapid inverse electron-demand Diels–Alder cycloadditions with tetrazines upon light-induced decarbonylation. Site-specific incorporation of methyl-tetrazine amino acids allows photo-induced protein labeling in living cells with spatio-temporal control using photo-DMBO fluorophore conjugates.

Taking shape: Polyethylene aerogels with low density and excellent mechanical resilience were obtained by combining and maximizing physical crosslinking, by crystallization, and chemical crosslinking, controlled by hydrosilylation reactions. These materials display remarkable shape-memory properties.

Particle in a frame: Gold particle-in-a-frame nanostructures with well-defined interior nanogaps were successfully generated through fine control over the galvanic replacement reaction of Ag nanoprisms with Au precursors. The prepared nanostructures exhibited enhanced plasmonic performance owing to their interior nanogaps, which strongly promote the plasmonic field.

To sum up: A carbon-coupled nickel nitride nanosheet was employed as an efficient electrocatalyst for 5-hydroxymethylfurfural (HMF) oxidation. In situ sum frequency generation (SFG) spectroscopy was used to explore the HMF electrooxidation process, and confirmed that the oxidation pathway proceeds via 5-hydroxymethyl-2-furancarboxylic acid (HMFCA).

Using amber-codon suppression, N^ϵ-acryloyl-lysine was genetically encoded in a phage-displayed peptide library for cyclization with a pre-installed cysteine. Selection from this phage-display library afforded cyclic peptides that bind TEV protease and histone deacetylase, HDAC8, much more strongly than their linear counterparts.

A highly reversible iodine plating cathode is presented that operates on the redox couples of I₂/[ZnI_x(OH₂)_4−x]^2−x in a water-in-salt electrolyte. The iodine plating cathode with the theoretical capacity of 211 mAh g⁻¹ plates on carbon fiber paper as the current collector, delivering a large areal capacity of 4 mAh cm⁻².

Not just one, but two: An organocatalytic asymmetric functionalization of unactivated benzylic C(sp³)−H bonds of alkyl indoles with trifluoropyruvates was developed with high enantioselectivity. Mechanistic studies and DFT calculations show an unusual mechanism, including the first installation of a trifluoropyruvate electrophile at C3 of indoles, towards the formation of the key enamine nucleophile, followed by the addition of the second trifluoropyruvate.

The right channel: Open 1D channels were able to recognize differences in molecular size when the pores were designed with a triangular shape and discrete size in covalent organic frameworks. This finding introduces the possibility of using 1D channels for selective transport and instant molecular separation with infinite selectivity (see picture).

Progressive metals: Be₅Pt is a rare representative of semiconductors that are formed by metallic elements only. The gap in the band structure appears due to both relativistic effects and a unique chemical-bonding situation with polar two-atom and multi-atom Pt–Be interactions.