Research articles

Electron spin resonance spectroscopy has traditionally been used to study large ensembles of spins, but its combination with scanning tunnelling microscopy recently enabled measurements on single adatoms. Now, individual iron phthalocyanine complexes adsorbed on a surface have been probed. Their spin distribution partially extends on the phthalocyanine, leading to a strong geometry-dependent exchange coupling interaction.

Several polymorphs of borophene have been synthesized on metal substrates, but typically as monolayers. Now large-size, single-crystalline bilayer borophene has been grown on Cu(111)—a sufficient electron provider to enable the bonding of the second boron layer. The resulting bilayer possesses a metallic character and is less susceptible to oxidation than its monolayer counterpart.

The use of ammonia as an alternative fuel relies on its electrochemical conversion to dinitrogen in a fuel cell. Now a stable metal–metal bonded diruthenium complex is shown to spontaneously produce dinitrogen from ammonia under ambient conditions and is also able to electrocatalyse the oxidation of ammonia to dinitrogen at low potentials.

A conjunctive olefination between aldehydes and carboxylic acids has been developed by merging photoredox catalysis with the Wittig reaction. The process uses a readily available phosphonium salt to join together complex molecular fragments with high functional group tolerance and minimal use of protecting groups, enabling access to coupling products with user-defined geometries.

Biosynthesis of aromatic amines typically uses glutamic acid or glutamine as the nitrogen donor. Now, a biosynthetic pathway to aromatic amines has been reported that uses glycyl-tRNA as the nitrogen donor. The myosin-targeting ammosamide is made via a pathway that involves the post-translational modification of a tryptophan, which is added to the end of a peptide in a tryptophanyl-tRNA-dependent step.

Weakly hydrated anions solubilize macromolecules but cause small molecules that are made from identical chemical constituents to precipitate out of aqueous solutions. Now, this phenomenon has been understood by demonstrating that the binding of anions to polymers is regulated by molecular curvature and interfacial water structure.

Imaging-based companion diagnostics can provide real-time information to match therapies to patients; however, glutathione is abundant in most cells, making it an unlikely candidate for companion diagnosis. Now, a chemical probe has been developed that can detect elevated glutathione concentrations via photoacoustic imaging. Using this probe enables normal and pathological states in a lung cancer model to be distinguished.

A haem protein that serves as a dual-function catalyst capable of inserting a carbene into a N–H bond to form α-amino lactones has been reported. The enzyme catalyses both carbene transfer and the subsequent proton transfer in a single active site. This transformation can proceed at the gram scale with high efficiency and enantioselective control.

Layered materials held together by weak interactions can be exfoliated into monolayers that retain the structure and composition of their bulk counterpart, but this has remained challenging to achieve for non-van der Waals materials. Now, AgCrS₂ has been exfoliated into such [CrS₂]Ag[CrS₂] nanosheets through intercalation with tetraalkylammonium cations chosen for their suitable redox potential. The nanosheets show superionic behaviour at room temperature.

Self-propelled artificial chemical swimmers have previously been developed for chemical sensing. Now, hybrid bioelectrochemical swimmers, capable of translating chiral molecular information into macroscopic motion, have been developed. Diastereomeric interactions between enantiopure oligomers immobilized on the swimmer and a chiral molecule present in solution control the trajectory of the device.

During polypeptide biosynthesis, a strong interaction can occur between a segment of an emerged, disordered nascent protein and the ribosomal surface. Now, it has been shown that competition between this ribosomal binding and the folding energetics of an immunoglobulin-like domain modulates the mechanism of co-translational folding.

Natural products are produced by living organisms practising nature’s chemical transformations. Now, an unnatural product has been generated by creating hybrid biosynthetic microorganisms. These microorganisms combine an unnatural chemical transformation—catalysis by an artificial metalloenzyme containing an iridium-based, unnatural cofactor—with a natural biosynthetic pathway within the same cell.

Carbon dioxide is a substantial component of many planetary atmospheres, but reduction of carbon dioxide requires conditions and substrates that are rare on planetary surfaces. Now, the reduction of carbon dioxide to organic species with biological relevance has been photochemically coupled to the oxidation of sulfite, suggesting that prebiotic carbon fixation could take place on the surfaces of rocky planets.

In biological systems, controlled molecular motion along a particular path is realized by protein motors that travel along microtubule filaments. Now, control of motion with light has been achieved in a synthetic supramolecular system, in which anionic porphyrin molecules move along the fibres of a bis-imidazolium gel upon irradiation.

Super-concentrated water-in-salt electrolytes enable high-voltage aqueous batteries, but have considerable drawbacks such as high viscosity, low conductivity and slow kinetics. Now a concentration-dependent association between CO₂ and TFSI^– has been discovered and leveraged to decouple the interphasial responsibility of an aqueous electrolyte from its bulk properties, making high-voltage aqueous Li-ion batteries practical in dilute salt-in-water electrolytes.

Located in the catalytically important belt region, the ‘ninth sulfur’ of the nitrogenase cofactor has now been shown to be inserted through coordination of sulfite by two cluster iron atoms at a vacant belt site. This is followed by in situ reduction of sulfite to sulfide, which enables the subsequent transfer and functionalization of the cofactor.

Selective C–H alkenylation of pyridines at the C3 position, with the pyridine as the limiting reagent, is a long-standing synthetic challenge. Now, it has been shown that this can be achieved using a bifunctional N-heterocyclic carbene-ligated Ni–Al catalyst that overrides the intrinsic C2/4 selectivity of pyridines and enables the selective late-stage functionalization of a range of complex pyridyl-containing motifs.

Chiral Brønsted acid catalysis is mostly limited to the activation of imine and carbonyl moieties. Now, by direct activation of alkynes, chiral Brønsted acids have been used to enable the catalytic asymmetric dearomatization of naphthol-, phenol- and pyrrole-ynamides for the construction of various spirocyclic enones and 2H-pyrroles bearing a chiral quaternary carbon stereocentre.

Liquid–liquid phase separation plays an important role in creating cellular compartments and protocells, but designing small-molecule models remains difficult. A peptide-based synthon for liquid–liquid phase separation consisting of two stickers and a flexible, polar spacer has now been presented. Condensates formed by these synthons can concentrate biomolecules and catalyse anabolic reactions.

Diazoolefins tend to be highly reactive compounds, and thus experimental evidence of these species is currently limited. Now, the reactivity and coordination chemistry of N-heterocyclic diazoolefins has been described. Diazoolefins are observed to form in reactions of N-heterocyclic olefins with nitrous oxide. The products benefit from resonance stabilization, enabling isolation on a preparative scale and comprehensive characterization.