News & Views in 2017

Molecular crystals have recently started to shake their inflexible reputation. Now, copper(II) acetylacetonate needles have been shown to be very flexible, and their mechanical deformation has been assessed through materials constants using methods customarily reserved for non-molecular materials.

Water-oxidation catalysts that are fast and efficient in strong acid are rare even though there are several benefits for systems working at low pH. Such catalysts usually feature expensive noble metals such as ruthenium and iridum; however, an electrocatalytic system that is exceptionally efficient and based on cobalt has now been developed.

The accumulation of multiple redox equivalents is essential in photo-driven catalytic reactions such as solar water splitting. However, direct spectroscopic observation of a twice-oxidized species under diffuse illumination has proved elusive until now.

Non-covalent interactions can organize planar molecules into two-dimensional arrays. It has now been shown that such arrays can be combined at the solid–liquid interface into bilayered heterostructures.

Building materials with clusters instead of atoms promises unconventional properties, but those 'superatomic solids' are often too fragile to manipulate. Now, intercalating a guest within an ionic layered solid made of fullerenes and metal chalcogenide clusters greatly alters its conductivity and optical properties without disrupting its crystalline structure.

The use of mechanical force to break and build chemical bonds in polymers can enable transformations that cannot be conducted using stimuli such as light and heat. Now, an insulating polymer has been mechanically unzipped to create a semiconducting polymer with extended regions of conjugation.

Although predicted many years ago, chemically reactive termolecular reactions were thought to be unimportant in defining the behaviour of combustion systems. Now, calculations have shown that such reactions between radicals and long-lived bimolecular complexes can actually play an important role in hydrogen combustion.

Understanding the biological roles of modifications to DNA, RNA and proteins is critical to revealing how cells regulate gene expression in development and disease. Two papers now present a combination of new tools and discoveries that could enable biologists and chemical biologists to better study epigenetic regulation in mammals.

Both the topology and the mechanical strength of woven materials have inspired great synthetic efforts to replicate their structures at the nanoscale. Now, a triaxial weave has been prepared by self-assembly of a judiciously designed organic molecule through π–π and CH–π interactions.

DNA double helical structures are supramolecular assemblies that are typically held together by classical Watson–Crick pairing. Now, nucleotide chelation of silver ions supports an extended silver–DNA hybrid duplex featuring an uninterrupted silver array.

Water is increasingly recognized as being of paramount importance in biological processes, yet its exact role remains difficult to elucidate. Now, the motion of water molecules within and around a synthetic peptide-amphiphile nanofibre has been precisely determined, showing significant differences between its core and surface.

Ejecting electrons from negative ions using light can create structures that very closely resemble the transition states of bimolecular reactions. Now, using this technique, trapped quantum states, or 'resonances', have been observed in a seven-atom reaction, and theory has been shown to be up to the task of capturing such complex phenomena.

Mathematically modelling metal–ligand bonding in late transition-metal complexes has been an important tool in catalyst development — although lacking for early transition metals such as Cr and Ti. Now, a simple method for measuring ligand donor properties promises to elevate high-valent early transition metal catalysis to the same level.

Merging the advantages of homogeneous and heterogeneous catalysts is a useful strategy for creating improved catalytic systems. Now, a concept has been developed that uses single Pd atoms — supported within liquid alloy droplets — that emerge from the droplet subsurface and interior to react with molecules approaching from the gas phase.

Intracellular protein delivery has been a major challenge in the field of cell biology for decades. Engineering such delivery is a key step in the development of protein- and antibody-based therapeutics. Now, two different approaches that enable the delivery of antibodies and antibody fragments into the cytosol have been developed.

The flow of energy in Earth's primary light harvesters — photosynthetic pigment–protein complexes — needs to be heavily regulated, as the sun's energy supply can vary over many orders of magnitude. Observing hundreds of individual light-harvesting complexes has now provided important insights into the machinery that regulates this process.

Disentangling the chemistry and physics behind reported unconventional superconductivity and exotic magnetism in alkali-intercalated PAHs has remained problematic due to the lack of phase-pure samples. Two synthetic pathways have now remedied this issue, facilitating studies of cooperative electronic properties based on carbon π-electrons.

Two papers provide insight into the reactivity of cytochrome P450s. A direct link between electron donation and reactivity has been shown with a selenocysteine-ligated P450 compound I, whereas a serine-ligated P450 (P411) has been engineered to catalyse an intermolecular C–H amination via nitrene transfer.

Lipid bilayers form the thin and floppy membranes that define the boundary of compartments such as cells. Now, a method to control the shape and size of bilayers using DNA nanoscaffolds has been developed. Such designer materials advance synthetic biology and could find use in membrane research.

Femtochemistry, the real-time study of reactions on a timescale that captures the molecular and atomic activity involved, has traditionally been performed in the gas or liquid phase. It has now been extended to the solid state in a study that highlights how a controlled reaction environment can place steric constraints on the motions of photoproducts.