Research articles

Amyloid cascades leading to peptide β-sheet fibrils are central to many diseases. Intermediate assemblies were recently identified as the toxic agents, but obtaining structural details of these early oligomers has largely been unsuccessful with traditional techniques. Here, ion mobility methods provide evidence for structural transitions from random to β-sheet assembly.

Characterization of plasma membrane proteins is important in understanding fundamental biological processes and developing new drugs, but their separation remains a challenge. Now, a synthetic receptor–ligand pair based on ferrocene derivatives and cucurbit[7]uril is shown to have exceptionally high binding affinity, and enables membrane proteins to be isolated efficiently without any contamination from naturally biotinylated molecules.

Aromatic hydrocarbons are among the most important building blocks in the chemical industry. Here, n-alkanes are catalytically converted to alkylaromatics, in yields up to 86%, using ‘pincer’-ligated iridium complexes and olefinic hydrogen acceptors. The carbon number of the n-alkanes is retained in the products, which are exclusively unbranched (n-alkyl-substituted).

Although most proteins fulfil their role as part of large protein complexes, little is known about the pathways of complex assembly. Here, ion mobility–mass spectrometry is used to monitor and structurally characterize the assembly intermediates of viral protein shells, called capsids, of two major human pathogens, norovirus and hepatitis B virus.

Ceramic preparation of spinels — materials useful for a wide range of applications — requires complicated procedures and heat treatment over long periods. Now, it is shown that rapid synthesis of nanocrystalline Co–Mn–O spinels can be achieved under ambient conditions, and the resulting nanoparticles exhibit considerable catalytic activity towards the electrochemical oxygen reduction/evolution reactions.

Larmor precession of a quantum mechanical angular momentum vector about an applied magnetic field forms the basis for NMR spectroscopy, MRI and a range of other important analytical techniques. This precessional motion has now been imaged for the first time, using velocity-map imaging in a model system of strongly polarized oxygen atoms.

Chain-reactions could provide an alternative method for surface patterning. Now the chain reaction of CH₃Cl molecules on a silicon surface has been observed to create lines that are made up of alternating CH₃ groups and Cl atoms. The reactions are propagated through surface-mediated charge-transfer and have been studied using microscopy and ab initio theory.

Nitrogen fixing is an extremely energy-consuming industrial process so there is much effort underway to develop better catalytic methods. Now, a dimolybdenum–dinitrogen complex bearing a PNP pincer ligand has been found to work as an effective catalyst for the formation of ammonia from dinitrogen.

Oxynitrides of transition metals are emerging materials with useful properties and improved stability over corresponding nitrides, but a full understanding of their anion ordering has been lacking. Now, a neutron and electron diffraction study of the perovskites SrNbO₂N and SrTaO₂N reveals the chemical principles for anion order and their potential influence on materials properties.

Water is the most abundant oxygen source, and is used as such by nature in photosynthesis. Now, it has been shown that photocatalytic oxygenation of organic substrates proceeds efficiently with water as the oxygen source, a manganese(III) porphyrin oxygenation catalyst, and a ruthenium complex as a photocatalyst.

Understanding how biosilica forms is crucial to our knowledge of this important biomaterial. Now, the role of collagen as structuring agent for the metre-long spicules of a primitive glass sponge has been revealed and found to have an unusual peptide motif.

Uranium oxo groups are very inert, in contrast with many transition metal oxo compounds that can carry out reactions that are difficult to achieve with other reagents. Now, the controlled lithiation of a ‘Pacman’ complex is shown to activate the uranium oxo group towards functionalization and single electron transfer.

The co-existence of superconductivity and magnetism in single compounds is rare, and heterostructures containing both properties have only been made with complex techniques. Now, a molecular-building-block approach has been applied to match organic and inorganic layers to produce multifunctional materials.

The self-assembly of planar molecules at interfaces can produce porous nanostructured surfaces that allow the selective trapping of guest molecules. By careful choice of both network and guest molecule it is possible to promote controlled, reversible growth perpendicular to the surface in the form of a molecular bilayer.

Specific molecular-recognition interactions are often used to build supramolecular architectures on very small length scales — typically those of molecules or macromolecules. Now, it has been shown that a host-guest system based on cyclodextrin rings and hydrocarbon groups can be used to direct the self-assembly of objects from macroscopic gel-based building blocks.

Phenylene oligomers are shown to form left- and right-handed helices in solution, but a chiral symmetry-breaking process occurs on crystallization to give a non-racemic mixture of crystals that each contains only one enantiomer. One-electron oxidation of the oligomers suppresses the interconversion of the mirror-image helices in solution, locking-in one conformation and leading to chiral memory effects.

Large polycyclic aromatic hydrocarbons or nanographenes have huge potential for organic electronics applications, but it is challenging to synthesize them in a controlled way. Now, a surface chemical route has been used to produce tailored nanographenes with atomically precise control over the final structure.

Using a chemical model, the binding of a monovalent ligand and the clustering of a membrane-embedded receptor are shown to be closely related processes that modulate each other without the contribution of any apparent multivalence effect.

Benzene-1,3,5-tricarboxamides are known to self-assemble via intramolecular hydrogen bonding into helical columnar aggregates. Here it is shown that the introduction of a stereocentre by an isotopic substitution — replacing hydrogen for deuterium on the methylene groups next to the amide — is sufficient to direct the helicity of the formed aggregate.

DNA has been used as a building block to make a wide variety of molecular architectures, but it remains difficult to make functional structures from this particular construction material. Now, a strategy for the assembly of hybrid RNA–DNA nanostructures has been described, which offers the possibility of combining the programmability of DNA with the rich functionality of RNA.