Research articles

Spin-crossover nanoparticles have been covalently grafted onto a semiconducting MoS₂ layer to form a self-strainable heterostructure. Under light or thermal stimulus, the nanoparticles switch between their high- and low-spin states, in which they have different volumes. This generates a reversible strain over the MoS₂ layer and, in turn, alters the electrical and optical properties of the heterostructure.

In polluted atmospheres, NO₂ oxidation of SO₂ in particles is a potentially important reaction leading to sulfate aerosol formation. Now it has been shown that the reaction occurs much faster than predicted by known bulk solution chemistry, implicating an interfacial mechanism.

Bicyclic hydrocarbons, and bicyclo[1.1.1]pentanes in particular, are playing an emerging role as saturated bioisosteres in pharmaceutical, agrochemical and materials intramolecular coupling approach has been developed for the modular construction of underexplored multisubstituted strained bicyclic hydrocarbons, ranging from [1.1.1] to [3.2.1] scaffolds.

The valorization of lignin is generally implemented through the cleavage of labile C–O bonds to produce aromatic monomers in up to 40 wt% yield. The remaining material consists of lignin dimers and oligomers connected by C–C bonds, but now a method has been developed for the oxidative cleavage of these C–C bonds using oxoammonium salts, to produce benzoquinones.

Triphenylphosphonium ylides (Wittig reagents) that selectively react with sulfenic acids—a pivotal post-translational cysteine modification in redox biology—are developed. This bioconjugation method enables a site-specific proteome-wide stoichiometry analysis of S-sulfenylation, and visualization of redox-dependent changes in mitochondrial cysteine oxidation and the redox-triggered generation of triphenylphosphonium for the controlled delivery of small molecules to mitochondria.

The use of anionic redox chemistry in high-capacity Li-rich cathodes is being hampered by voltage hysteresis, the origin of which remains obscure. Now it has been shown that sluggish ligand-to-metal charge transfer kinetically traps an intermediate Fe⁴⁺ species and is responsible for voltage hysteresis in the prototypical Li-rich cation-disordered rock-salt Li_1.17Ti_0.33Fe_0.5O₂.

A deep chemical proteomic investigation of diverse aminophilic electrophiles has identified ligandable lysines across a wide range of human proteins. The proteins cover different functional and structural classes, and the aminophilic electrophiles include compounds that disrupt protein–protein and protein–RNA interactions. This dataset provides a proteome-wide atlas of lysine-reactive chemistry.

Coulombic interactions can be used to assemble charged nanoparticles into higher-order structures, but this process typically requires similarly sized oppositely charged partners. Now, small anions or cations with as few as three charges have been shown to induce attractive interactions between oppositely charged nanoparticles in water, guiding the assembly of colloidal crystals.

Tailoring the size and connectivity of organic nanostructures is challenging but is often key in molecular electronics for tuning the properties of the quantum materials. Now an approach has been developed for building low-dimensional covalent architectures block by block on a surface by highly selective tip-induced intermolecular reactions.

The correct function of ribozymes in a prebiotic world would be dependent on the presence of optimal salt compositions and concentrations. Now, local heat fluxes have been shown to create an ideal salt habitat for ribozyme activity based on geologically plausible salt-leaching processes.

The construction of mechanically interlocked molecules solely made from peptides is a great synthetic challenge because of a lack of effective templating strategies. Now it has been shown that by combining self-assembly and dynamic covalent chemistry, catenanes, daisy chains and other interlocked peptides can be synthesized from genetically engineered building blocks.

Non-canonical amino acids can be incorporated into proteins through translation of orthogonal mRNAs. Now, automating the design of orthogonal mRNAs—which are more selectively and efficiently translated—in combination with compact orthogonal aminoacyl-tRNA synthetase/tRNA expression systems, enables the incorporation of four distinct non-canonical monomers via a 68-codon genetic code.

The opening mechanism of the SARS-CoV-2 spike protein has been studied by integrating computational and experimental data. Combining weighted ensemble molecular dynamics simulations, biolayer interferometry and ManifoldEM analysis of cryo-EM data revealed that the glycan at N343 plays a gating role in the opening mechanism of the SARS-CoV-2 spike protein.

Computationally designed enzymes can be substantially improved by directed evolution. Now, it has been shown that evolution can introduce a dynamic network that selectively tightens the transition-state ensemble, giving rise to a negative activation heat capacity. Targeting such transition state conformational dynamics may expedite de novo enzyme creation.

Sulfur(vi) fluoride exchange (SuFEx)—a type of click chemistry that generates S^VI-centred covalent linkages—has previously been used for polymer synthesis. Now, modular SuFEx polymerization using SOF₄ has been used to generate helical polymers. Unlike previous examples of SuFEx polymerization, the backbone retains S^VI–F motifs and therefore is able to undergo further SuFEx click reactions, enabling facile and efficient post-polymerization modification.

Although organocatalysis has emerged as a powerful catalysis platform, its application for the selective transformation of inactive arenes remains challenging. Now, an organocatalyst-controlled site-selective C–H functionalization of arenes has been developed, with wide substrate generality and applicability, offering a general strategy for arene transformation.

As the number of atoms involved in a reaction increases, so do the experimental and theoretical challenges faced when studying their dynamics. Now, using ion-imaging experiments and quasi-classical trajectory simulations, the dynamics of the polyatomic reaction F^– + CH₃CH₂Cl have been studied and the competition between bimolecular nucleophilic substitution and base-induced elimination has been disentangled.

Nature uses out-of-equilibrium systems to control hierarchical assembly. Now, a dissipative chemical system has been shown to slowly release monomer DNA strands from a high-energy reservoir, regulating self-assembly by switching the mechanism of supramolecular polymerization at the single-molecule level. This process heals fibre defects, converting branched, heterogeneous networks into nanocable superstructures.

The breakdown of the Born–Oppenheimer approximation is omnipresent in chemistry and detailed understanding of non-adiabatic dynamics is still incomplete. Now, the non-adiabatic quenching of electronically excited OH(A²Σ⁺) molecules by H₂ has been investigated using full-dimensional quantum dynamics calculations and a high-quality diabatic-potential-energy matrix, providing insight into the branching ratio of the two electronic quenching channels.

Machine learning has now been shown to enable the de novo design of abiotic nuclear-targeting miniproteins. To achieve this, high-throughput experimentation was combined with a directed evolution-inspired deep-learning approach in which the molecular structures of natural and unnatural residues are represented as topological fingerprints. The designed miniproteins, called Mach proteins, are non-toxic and can efficiently deliver antisense cargo in mice.