Controlled protein interactions are desired for any material in a biological environment. These interactions can be characterized with a combination of techniques developed for curved as well as planar surfaces, and ideally enable engineering of functional material surfaces.

More than one HAT: Hexaazatriphenylene (HAT) derivatives are suitable building blocks for the systematic construction of stable hydrogen-bonded frameworks. The derivative with carboxybiphenyl groups forms a stable single-crystalline porous framework (CBPHAT-1 a) that displays protic solvent durability, heat resistance up to 305 °C, and SA_(BET) of 1288 m² g⁻¹.

A scalable one-pot reductive method produces stable solutions of single- and few-layer two-dimensional graphitic carbon nitride (gCN) nanosheets in high yield (35 %). Atomic-resolution imaging confirms an undamaged crystalline structure with AB stacking. The anionic charge provides a versatile route for functionalisation, as illustrated by alkylation.

Cl-ever cats: HCl was used as a hydrogen-atom-transfer catalyst precursor and activated to give chlorine radicals by an acridinium photoredox catalyst under visible-light irradiation in a microtubing reactor, which was effective in retaining the volatile HCl catalyst. This photomediated C−H activation strategy enabled the efficient alkylation and allylation of a variety of unactivated, even primary, C(sp³)−H bonds (see scheme).

Coupling strategies for surface-based kinetic assays based on the enzymes Sfp, SrtA, and OaAEP were developed to site-specifically and covalently ligate proteins of interest through short recognition sequences. The enzymes function under mild conditions without affecting the receptor fold, thereby enabling study of the binding kinetics of receptor–ligand pairs that are inaccessible to nonspecific surface chemistry.

A worthy COS: Chiral sulfur-containing polymers with good thermal and optical properties were synthesized for the first time by stereoselective desymmetrization copolymerization of achiral meso-epoxides and COS. The reaction is catalyzed by an enantiopure binaphthol-linked bimetallic catalyst and provides the polymers with >99 % isotacticity.

Gold nanoparticles functionalized with a chelating tetradentate porphyrin ligand exhibit significantly improved catalytic activity and stability for electrochemical CO₂ reduction. The inherent structural and electronic tunability of these nanoparticles offers an unrivaled degree of control over their reactivity.

Beating brine: Using two different DPA-based oligo-ligands (a bis-ligand, L₂ and tris-ligand, L₃) and metal ions, a supramolecular polyelectrolyte system was produced with cross-links, the number of which can be varied by varying the L₃/L₂ ratio. Combining this with a charged-neutral diblock copolymer led to M-L₂-L₃ micelles with tunable and enhanced salt stability and magnetic relaxivity that perform well as an MRI contrast agent.

Boron-alkylated BODIPY is used as a probe for single-molecule localization-based super-resolution microscopy. Photoactivation and excitation is achieved with a single visible-light laser and without additives in the imaging medium. Microtubules are imaged with a paclitaxel-attached probe to demonstrate the super-resolution imaging ability of cellular structures.

The electrophilicities (E) of trifluoromethylthiolating and difluoromethylthiolating reagents were investigated by following the kinetics of their reactions with a series of enamines and carbanions with known nucleophilicity parameters. The electrophilicity parameters determined for these reagents cover a reactivity range of 17 orders of magnitude.

Template synthesis: Pairs of trans-4-styrylpyridine or its derivatives are oriented in a parallel and head-to-tail (HT) manner for the solid-state photodimerization within a pseudorotaxane-like MOF. The high selectivity for the rctt-HT dimers provides a controlled photodimerization within a confined environment. These results are in striking contrast to the mixtures of products and low yields obtained by untemplated photodimerization in organic solvents.

S-propargyl-cysteine (SprC) was genetically encoded into proteins at the interface to cross-link proteins and at the active site to mask an enzyme, which was chemically activated by Pd(TPPTS)₄. In addition, molecular modifications were installed onto proteins via Sonogashira cross-coupling on SprC by Pd(NO₃)₂, and then tracelessly removed with Pd(TPPTS)₄.

Sweet but deadly: Phosphonium-based polymers appended with hydrophilic groups such as sugars or hydroxy groups can be employed as highly effective antibacterial agents against both Gram-negative and Gram-positive bacteria with minimal haemolysis of red blood cells. This challenges the conventional wisdom that hydrophobic appendages are necessary for this class of biocides.

Glowing radical: A photostable luminescent organic radical was doped into host molecular crystals. The 0.05 wt % doped crystals displayed bright luminescence with a room-temperature emission quantum yield of 89 %. The 10 wt % doped crystals show large changes in their emission spectra on applying a magnetic field at 4.2 K. This is the first observation of magnetoluminescence in organic radicals.

A covalent organic framework functionalized with triphenylamine and naphthalenediimide units was used as a cathode. It could synergize photoinduced charge transfer with reversible electrochemical (de)lithiation processes. This leads to decreased charge voltage (by 0.5 V), increased discharge voltage (by 0.5 V), and an extra 38.7 % battery efficiency under illumination.

A bimetallic, bifunctional catalyst composed of iron–ruthenium nanoparticles immobilized on an acid-functionalized supported ionic liquid phase (FeRu@SILP+IL-SO₃H) was developed. This catalyst showed high activity for the hydrodeoxygenation of aromatic ketones and excellent selectivity towards aromatic deoxygenation products.

Solar-renewable colorful organic mechanoluminescence (ML) materials are induced by introduction of alkyl chains. Colorful ML from a polycrystalline thin film can be repeated interactively and totally for preliminary sandwich-type ML device applications by simply recrystallizing the fractured crystal in situ after non-contact exposure to sunlight in less than one minute.

Prosthetic-group-free: The combination of photoactivated sodium decatungstate and [¹⁸F]-N-fluorobenzenesulfonimide effects site-selective ¹⁸F-fluorination at the branched position in leucine residues in unprotected and unaltered peptides. This streamlined process provides a means to directly convert native peptides into PET imaging agents under mild aqueous conditions.

Another trick up their sleeve: Pyridine and quinoline N-oxides underwent efficient reductive alkylation with Wittig reagents under mild conditions to provide a variety of C2-alkylated pyridines and quinolines with excellent site selectivity and functional-group compatibility (see scheme). Straightforward sequential C−H functionalization and postfunctionalization enable the synthesis of diverse bipyridyl ligands by this method.

A CB[8]-receptor-indicator complex for detection of amphiphilic compounds has been prepared. It has a hydrophilic receptor to bind a sugar head group, a hydrophobic macrocycle to bind the lipid portion of the analyte, and an indicator. Upon addition of a glycolipid, a clear increase of fluorescence was detected.

Germanium is for the first time reported to incorporate in all-inorganic CsPbI₂Br perovskite and lead to enhanced phase stability and photovoltaic performance. A large V_OC of up to 1.34 V and a high PCE of 10.8 % were achieved by planar perovskite solar cells (PSCs) that were prepared in an uncontrolled humid air atmosphere without a glovebox, which are remarkable records for the CsPbI₂Br PSCs.

Protective coat: Air-stable lithium spheres formed in a CO₂ environment at the carbon nanotube (CNT), Li₂O, and CO₂ triple point upon applying a negative potential. The high air stability is due to the formation of a Li₂CO₃ surface passivation layer.

Probing protonation: Two-color valence-to-core X-ray emission spectroscopy is used to probe the protonation patterns of several metallocofactor oxidation states involved in the activation of a class I-c ribonucleotide reductase from Chlamydia trachomatis. These spectra—augmented by insight from DFT computations—allow assignment of Mn^IV(O)₂Fe^IV and Mn^IV(O)(OH)Fe^III states during enzyme activation.

Posthaste: Poly(propylene fumarate) was functionalized with chlorine, alkyne, and nitrophenyl groups by ring-opening copolymerization of modified epoxides and maleic anhydride. These polymers can be modified by post-polymerization and post-printing.

Unlike in ABX₃ perovskites (X=halide), the band-gap transition in A₂BB′X₆ double perovskites has substantial metal-to-metal (B to B′) charge-transfer character, which allows access to small band gaps by aligning the energies of the B-site metal frontier orbitals, as exemplified in the new double perovskites Cs₂AgTlX₆; X=Cl and Br.

Break the trap: Inefficient endosomal escape into the cytosol has been a bottleneck in intracellular delivery of biomacromolecules. With appropriate chemical modifications, a cationic amphiphilic peptide, Mastoparan X, became a useful delivery tool that selectively disrupts the endosomal membranes and releases entrapped materials.

An atom-precise Ag₁₂@POSS₆ dendritic complex (POSS=polyhedral oligomeric silsesquioxane) has been synthesized. The central silver(I) cluster core underwent a reversible structural transformation with solvent stimuli, leading to the rearrangement of the shell POSS clusters from pseudo-octahedral to quasi-octahedral.

Chelator in disguise: Dithiocarbamate, a metal ion chelator, is masked for its ability to bind to Cu^II with a γ-glutamyl transpeptidase (GGT) enzyme trigger. Activated by GGT overexpressed in cancer cells, the chelator is unveiled to form cytotoxic Cu complexes in situ selectively in GGT-expressing cancer cells.

The unique solvation properties of diiodomethane towards halide-containing organometallic species are associated with its enhanced σ-hole-donating ability, which leads to stronger solvent–(metal complex) halogen bonding. The introduction of additional halogen atoms in the organometallic species attenuates the strength of the halogen bonding.

Waiting for a mate: A bismuth oxide nanosheet/nitrogen-doped graphene quantum dot composite catalyst (NGQDs) for the highly efficient electrochemical reduction of CO₂ to formate was prepared. NGQDs significantly enhance the activity of Bi₂O₃ nanosheets, achieving almost 100 % formate Faraday efficiency at a moderate overpotential of 0.7 V and an average formate Faraday efficiency of 95.6 % over a wide negative potential range from −0.9 V to −1.2 V vs. RHE.

Metamorphic proteins are prone to adopting alternative conformations. By performing a comparative study on the denatured states of two proteins sharing nearly identical amino acid sequences (88 %) but different topologies, a site-directed mutant, resulting in a switch in the folding, was designed. This finding represents a direct demonstration of the role of the denatured state in dictating the selection of pathways to the native state.

Catalytic conjunctive cross-coupling has been developed to construct enantiomerically enriched tertiary alkylboronic esters. These reactions occur with good yield and enantioselectivity for a range of substrates. Mechanistic experiments reveal aspects of the catalytic cycle that allow hindered substrates to react without significant complicating side reactions.

NO resting in a nest: A metal-free electron spin system was constructed by just encapsulating an NO molecule inside an open-cage fullerene C₆₀ derivative. The molecular complex displayed unique properties, reflecting the fact that the NO molecule is paramagnetic.

Under pressure: The discovery of the first intermetallic compound in the Cu-Pb system, Cu₃Pb, by high-pressure synthesis in a laser-heated diamond anvil cell, is presented.

Protective coating: The stability of lithium anodes plays a vital role in improving the cycle life of Li-O₂ batteries. A convenient method is presented to produce a film on a lithium surface by chemical reactions between lithium metal and 1,4-dioxacyclohexane. The protective film could reduce the morphology changes and suppress the parasitic reactions of lithium anodes and endow Li-O₂ batteries with enhanced cycling stability.

A radical approach: A photochemical asymmetric radical cascade process that converts unactivated olefins and α,β-unsaturated aldehydes into chiral adducts in a single step is reported. This enantioselective strategy, which is triggered by the excited-state reactivity of chiral iminium ion intermediates, combines two sequential radical-based bond-forming events.

More than once in a lifetime: Wavelength- and lifetime-engineered upconversion nanoparticles can dramatically expand the encoding capacity for multiplexed detection and imaging.

A sensitive fluorescent probe capable of detecting trace ^.OH from iron autoxidation is developed by utilizing both the unique aromatic hydroxylation and the electrophilicity of ^.OH. The capability of the probe is demonstrated by imaging ^.OH generated in living cells under iron autoxidation and various stimuli, revealing that the basal ^.OH level in RAW 264.7 cells is lower than that in HeLa cells.

Off the PEG: Ruthenium-catalyzed ring-closing metathesis (RCM) under careful control of the catalyst, concentration, and temperature allows the stereocontrolled synthesis of 1,4-linked six-membered cyclopolyethers. Post-polymerization modification by dihydroxylation (DH) affords polymers with a poly(ethylene glycol) backbone and sugar-like functionalities (“PEGose”).

Fe-containing Co and Ni (oxy)hydroxides are the fastest-known catalysts for water oxidation in alkaline conditions. Fe is essential to the high activity, but its role in the mechanism is under active investigation. Now it is shown that oxygen evolution is concurrent with the oxidation of Fe cations and shortening of Fe−O bonds. The results are consistent with density functional theory calculations and may indicate Fe-based active sites.

Energy-efficient separation of aromatics and cyclic aliphatics is a major industrial sustainability challenge. A flexible molecular material, namely nonporous adaptive crystals of pillararenes, can be used to separate them. Pillar[5]arene is shown to separate vapors of toluene from methylcyclohexane, while pillar[6]arene separates methylcyclohexane from toluene with over 98 % specificity in the solid state.

DES-SELEX: Aptamers can be selected in deep eutectic solvents composed of choline chloride and 1,2-ethanediol faster than in aqueous media. These highly solubilizing media, mimicking the intracellular environment, allow targeting non-soluble or poorly water-soluble species, which include targets of great interest in biomedical, pharmaceutical, and food analysis.

In situ IR spectroscopy provides insight into the mechanism of the oxygen reduction reaction on supported platinum. Observation of adsorbed superoxide and hydroperoxide provides evidence for an associative contribution to the mechanism. Further correlation with the catalytic current suggests that an additional pathway is also important at high potential.

YPhos: The ylide-functionalized phosphines (YPhos), a novel class of strong donor ligands, are readily accessible from commercially available starting materials and exhibit easily tunable electronic and steric properties. The huge potential of these ligands in catalysis is demonstrated by their use in gold catalysis, with excellent performance observed at low catalyst loadings under mild reaction conditions.

Functionalization of dinitrogen by B−H bonds, through three successive B−N bond formations at room temperature leads to the formation of borylamines.

Se salt: The use of trisubstituted selenonium salts as organic Lewis acids in electrophilic halogenation and aldol-type reactions has been developed. The substrate scope is broad. The reaction conditions are mild and compatible with various functionalities. This study opens a new avenue for the development of non-metallic Lewis acid catalysis.

Although η²-H−EX_n σ-complexes are well-known when E is a Group 13 or 14 element (E=B, Al, Ga, C, Si, Ge, Sn), η²-H−EX_n σ-complexes where E is a period 6 main-group element were previously unknown. Now the synthesis and structural characterization is presented of ruthenium σ-complexes [CpRu(PP)(η²-(H-Tl))]⁺ (PP=dppm, dppe), which contain TlH, a hydride of a period-6 main group element.

To the nines: Structurally defined fucosylated chondroitin sulfate hexa- and nonasaccharides were synthesized in 12 linear steps from chondroitin sulfate through the enzymatic degradation of chondroitin (see scheme). The nonasaccharide displayed selective intrinsic factor Xase complex inhibitory activity by binding to factor IXa with high affinity, thus showing promise for the development of anticoagulant agents targeting the intrinsic coagulation pathway.

Lamellar MFI zeolite nanosheets (2D-MFI) contain a large fraction of partially confined H⁺ sites ( ) residing at the micro- and mesopore intercepts, which are effective for C=C bond coupling and ring closure of aldehydes to produce aromatic compounds. These sheets resemble a nanometer-sized plug flow reactor; they promote formation and effective removal of aromatic products in cascade reactions, thus mitigating coke deposition.

A three-step transformation consisting of 1) addition of electrochemically generated iodosulfonium ions to vinylarenes, 2) nucleophilic substitution by subsequently added aromatic compounds, and 3) elimination of HI with a base enables metal- and oxidant-free alkenyl C−H/aromatic C−H cross-coupling. This one-pot transformation provides an easy access to various 1,1-diarylethylenes.

Fluoresce de Résistance: The demethylase ALKBH2 is critical for repairing DNA; however, it can be hijacked in tumors to develop chemotherapy resistance. The first fluorescent sensors for ALKBH2 are reported that specifically detect its activity in real-time both in vitro and in cell lysates. Assays are developed for direct quantification of cellular ALKBH2 activity in response to chemotherapeutics as well as high-throughput screening.

An enantioselective C−H arylation of phosphine oxides with o-quinone diazides is catalyzed by a Cp^xIr^III complex and chiral carboxylic acid co-catalyst. It provides a unifying access to P-chiral phosphine oxides, atropo-enantioselective construction of sterically demanding biaryl backbones, and a selective assembly of axial and P-chiral compounds in excellent yields and diastereo- and enantioselectivities.

Doubling up on M n' Mn: Hydroarylation of unsymmetrical 1,3-diyne alcohols with arylboronic acids, catalyzed by a dimeric Mn^I catalyst, has been achieved with predictive regio-, stereo-, and chemoselectivity. It offers a general, convenient, and practical strategy for the modular synthesis of multisubstituted Z-configurated conjugated enynes.

Two chlorinated polymers were designed and synthesized. They exhibited significantly different optical, electrochemical, organizational, and photovoltaic properties.

A palladium-catalyzed [3+2] cycloaddition of racemic allenes to form densely functionalized chiral allenes has been developed. This catalytic asymmetric procedure was utilized to obtain various cyclopentanes, pyrrolidines, and spirocycles with very good control over the regio-, enantio-, and diastereoselectivity.

Two rings: A copper-catalyzed enantioselective alkene carboetherification that provides 5,5-, 5,6-, and 6,6-spirocyclic products containing fully substituted chiral carbon centers, with up to 99 % enantiomeric excess, is disclosed. This reaction features the formation of two rings from acyclic 1,1-disubstituted alkenols functionalized with arenes, alkenes, or alkynes, and is a powerful approach to the synthesis of chiral spirocyclic ethers.

The cross-coupling between diverse esters and amines to form amides is enabled by the use of Ni catalysis. Unlike traditional approaches to amide bond formation, the reaction works in the absence of acidic or basic additives, and both aliphatic amines and aniline derivatives can be effectively utilized.

Asymmetric catalysis: (Diborylmethyl)zinc(II) species have been generated by transmetalation between isolable (diborylmethyl)lithium and zinc(II) halides. The zinc(II) species have been applied to the synthesis of enantioenriched gem-diborylalkanes through iridium-catalyzed asymmetric allylic alkylation reaction.

The cobalt-catalyzed asymmetric diborylation of gem-disubstituted alkenes enables the highly enantioselective synthesis of chiral gem-bis(boryl)alkanes. The synthetic utility of these products was exemplified through several stereospecific derivatizations and the synthesis of sesquiterpene and sesquiterpenoid natural products.

Making a transfer: Diversity-oriented, remote, site-selective radical C−H functionalization of unactivated C−H bonds is achieved using stable and readily accessed substrates. C−H functionalization proceeds by 1,5-hydrogen atom transfer followed by trapping with various sulfonyl derivatives.

With HAT in hand: Reported here is a photoinduced radical cascade strategy for the divergent functionalization of amides and protected amines. It is based on the oxidative generation of electrophilic amidyl radicals and their subsequent transposition by 1,5-H-atom transfer, which results in remote fluorination, chlorination, thioetherification, cyanation, and alkynylation. This strategy was used for the late-stage functionalization of amino acids and a dipeptide.

Polyanionic silicon clusters are provided by the Zintl phases K₄Si₄, comprising [Si₄]⁴⁻ units, and K₁₂Si₁₇, consisting of [Si₄]⁴⁻ and [Si₉]⁴⁻ clusters. Charged Si₉ clusters were detected for the first time by ²⁹Si NMR spectroscopy in the solid state and in solution. ²⁹Si and ¹H NMR spectra reveal the [H₂Si₉]²⁻ cluster anion in solution and J(²⁹Si—¹H) coupling shows these is proton scrambling.

It's flexible! The characteristic multiplicity patterns of ²⁹Si and ¹H NMR resonances and CEST studies reveal the highly dynamic behavior of [HSi₉]³⁻ in solution. Theoretical considerations corroborate a highly dynamic Si₈ entity and a Si−H moiety with slow proton hopping. A monocapped square-antiprismatic structure with the H atom localized at one vertex of the basal plane was identified in single-crystal studies.

A zirconium-based MOF with calixarene linkers was synthesized and characterized. It exhibits a complex three-dimensional pore system that exposes the calixarenes for the selective detection of NO₂. The impressive and reversible color change from white to blue makes the material a visual sensor for NO₂ at room temperature.

A fully atom-economic gold-catalyzed reaction enables the direct synthesis of substituted azulenes from easily accessible starting materials. A fluorine substituent as a strong +M donor initiates this reaction. The obtained scaffolds can be easily functionalized at the seven-membered ring in a selective manner.

Throw oxygen out in the cold: The simple methylation of endoperoxides of pyridylanthracenes causes the release of oxygen at room temperature. Furthermore, even reactive singlet oxygen can be generated under such mild conditions and was applied for oxidations.