Articles in 2023

The energy density in redox flow batteries is currently limited by the solubility of dissolved redox species. Now it has been shown that intermolecular C–H···π interactions can disrupt electrostatic forces in these organic electrolytes to improve their solubility in non-aqueous solvents.

The design and improvement of enzymes based on physical principles remain challenging. Now, the vibrational Stark effect has been used to demonstrate how an electrostatic model can unify the catalytic effects of distinct chemical forces in a quantitative manner and guide the design of enzyme variants that outperform their natural counterpart.

Although gas bubble dynamics during electrochemical processes dramatically affect performance, the fundamental understanding and manipulation of such dynamics have been limited. Now, electrolyte composition is found to be a key factor in inducing a solutal Marangoni instability that impacts both H₂ gas detachment and coalescence between H₂ microbubbles.

Bicyclic lactones are valuable motifs for the synthesis of natural products and bioactive molecules. Now, a palladium-catalysed protocol has been developed to access unsaturated bicyclic lactones in one step from corresponding carboxylic acids. The method demonstrates reverse site selectivity for C(sp³)–H activation to form diverse bicyclic cores.

Pump–probe measurements conventionally achieve femtosecond time resolution for X-ray crystallography of reactive processes, but the measured structural dynamics are complex. Using coherent control techniques, we show that the ultrafast crystallographic differences of a fluorescent protein are dominated by ground-state vibrational processes that are unconnected to the photoisomerization reaction of the chromophore.

The coupling of autocatalysis to compartment growth and division is a key step in the origin of life. Now it has been shown that compartmentalizing the formose reaction in emulsion droplets leads to several crucial properties of living and evolving systems (growth, division, variation, competition, rudimentary heredity and selection).

While chiral hybrid organic–inorganic perovskites are promising materials for optoelectronic applications, the synthesis of three-dimensional single crystals has proven challenging. Now, a general strategy has been shown to synthesize chiral, three-dimensional perovskites by heterogeneous nucleation. The single-crystalline materials contain no chiral component; their chiroptical activity arises from supercells formed by chiral patterns of the A-site cations.

Interpenetration—in which two or more lattices are catenated—is common in metal–organic frameworks (MOFs). Now a deliberate synthesis of hetero-interpenetrated MOFs, with two distinct lattices, has been developed. It can combine the different properties of the two sublattices in one material, as demonstrated with chirality and catalytic activity, delivering an asymmetric catalyst.

Functionalizing two-dimensional transition-metal carbide (MXene) surfaces can alter their properties, but covalent functionalization has been synthetically challenging. Now, it has been shown that various organic groups can be covalently attached to MXene surfaces through amido and imido bonds. The resulting hybrid organic–inorganic structures exhibit Fano resonances and superior stability compared with traditional MXenes with a mixture of –F, –O and –OH surface terminations.

Understanding interfacial and cellular electron transport is essential for guiding efficiency optimization in microbe–semiconductor biohybrids for energy conversion. A multimodal imaging platform that combines optical imaging and photocurrent mapping can now interrogate such electron-transport pathways at the single-cell level, uncovering different roles of hydrogenases and a microbe’s large electron-uptake capacity.

Three-protein conjugates, which have so far been produced using protein-engineering strategies, can now be generated using a chemical approach that enables the addition of small-molecule functionality. Checkpoint inhibitory T cell engagers (CiTEs) were assembled and shown to have enhanced in vitro potency compared to a traditional T cell engager.

Quantum state-to-state understanding of collisional charge transfer is a long-time goal of chemical dynamics. Now, using high-resolution molecular-beam experiments with spin–orbit state-selected ions and surface-hopping calculations, a vibrational-state-specific mechanism has been observed for the reaction Ar⁺(²P_3/2) + N₂ → Ar + N₂⁺(v′, J′). Besides the well-known long-range harpooning mechanism, a hard-collision glory scattering mechanism was also identified.

Most chemoproteomic screening approaches are indirect. Now, a chemoproteomic platform based on chiral sulfonyl fluoride probes has been developed for the direct identification of probe-modified tyrosines and lysines in live cells. Stereoselective modification by structurally diverse probes was observed for 634 tyrosines and lysines across functionally diverse protein sites.

The streamlined synthesis of multiple (proto)biomolecules from common starting materials is a key goal of prebiotic chemistry. Now, a one-pot synthesis of ribo-aminooxazoline (a precursor for prebiotic nucleotide synthesis) from HCN has been achieved. Additionally, the two moieties used in extant terpenoid biosynthesis have been accessed, with all carbon atoms also originating from HCN.

Rapid solvent flows stretch dissolved polymer chains to their breaking point by hitherto-elusive molecular mechanisms. Now, analysis of competing mechanochemical reactions suggests a broad distribution of molecular geometries of fracturing chains. This occurs because, in each chain, fracture and kinetically destabilizing backbone stretching compete on submillisecond timescales.

The kinetics of liquid–liquid phase separation (LLPS) in cell-like confinements remains poorly understood. Now it has been shown that it involves complex interplay between the incipient phases and the membrane boundary, which arrests phase coarsening, deforms the membrane and couples LLPS with lipid phase separation.

In the atmosphere, photolysis of formaldehyde generates H and HCO radicals, which then react with O₂ to form HO₂ (important in converting atmospheric carbon to CO₂). Now it has been shown that internally excited formaldehyde can also react with atmospheric O₂ to make HO₂ in a direct, one-step ‘photophysical oxidation’, a mechanism likely to be general in the troposphere.

Although Li–O₂ batteries offer high theoretical capacities, redox mediators are necessary to control intermediate reaction kinetics and to limit electrode passivation. Now it has been shown that a family of triarylmethyl cations can rival top-performing quinone-based redox mediators. Cations with sluggish catalytic rates were found to suppress surface-mediated O₂ reduction and achieve higher capacitances.

Allostery produces concerted functions of protein complexes by orchestrating the cooperative work between the constituent subunits. By restoring functions of pseudo-active sites that have been lost through evolution, allosteric sites have now been designed into a rotary molecular motor, V₁-ATPase, resulting in its rotation being boosted allosterically.

Scandium is challenging and expensive to isolate in pure form using conventional solvent extraction. Now a covalent organic framework (COF) has been synthesized that can incorporate scandium coordination complexes; subsequent removal of the scandium ions generates open coordination sites, and the resulting ‘metal-imprinted’ COF can be used for highly selective, cyclable scandium capture.