Reviews & Analysis

One goal of synthetic biologists is to develop artificial systems to help study biological processes. Now, cell communication and differentiation have been demonstrated using spatiotemporal patterns created in artificial multicellular compartments.

Gold nanomaterials are attractive for a variety of applications, including in medicine, but need to be made stable enough to operate in biological systems. Now, gold nanorods have been stabilized for photothermal therapy by sequential surface anchoring, using a bidendate PEG-based ligand that features a thiolate moiety and an Au–NHC moiety.

Covalent organic frameworks (COFs), whose heterogeneous backbones can be easily tuned at the molecular level, are promising photocatalysts for artificial photosynthesis. Sulfone-rich crystalline, wettable COFs have now been shown to exhibit high photocatalytic hydrogen evolution rates with platinum nanoparticles as co-catalysts.

Superoxide dismutase mimics can help regulate the levels of O₂^•− in the body, but typically rely on redox-active metals that are toxic in their free form. Now, a complex featuring a redox-active quinol moiety complexed to a redox-inactive zinc centre has been shown to catalyse O₂^•− dismutation.

Magnetic or electric fields have long been used to align or orient atomic or molecular species in a molecular beam. Now, experiments in a merged beam apparatus show that an external magnetic field can be used to favour one particular reaction path.

The structural features and catalytic performances of catalyst particles have now been correlated using a fluorescence microscopy approach, by tracking nanoprobes as well as fluorescent reaction products. Such mapping enables exploration of structure–function relationships, which is essential for the design of better catalysts.

The applicability of metal-organic frameworks (MOFs) — in spite of their obvious potential — is hindered by stability issues, in particular towards water. Now, a ‘crumple zone’ concept has been proposed in which the presence of sacrificial bonds protects a MOF without significantly altering its structure or functionality.

Dynamic covalent chemistry combines the error-correcting behaviour of supramolecular chemistry with the robustness of covalent bonding, but relies on a somewhat limited set of reactions. Now, the classic nucleophilic aromatic substitution (S_NAr) reaction has been shown to be reversible and self-correcting.

Probing single-atom alloys has shown that, when interactions between the components are weak, the electronic structure of the dilute element resembles that of a free atom, making bonding with reactants more like that in molecular homogeneous catalysts.

The structure of an antibiotic that is effective against Gram-positive bacteria, but not against Gram-negative bacteria, has now been modified to improve its effectiveness against Gram-negative bacteria. The approach could help broaden the spectrum of activity of other antibiotics.

Knots have been rigorously studied since the 1860s, but only in the past 30 years have they been made in the laboratory in molecular form. Now, the most complex small-molecule examples so far — a composite knot and an isomeric link, each with nine crossings — have been prepared.

The preparation of three-dimensional frameworks with multiple stereocentres from simple acyclic hydrocarbons represents a challenging transformation. Now, starting from simple and readily available reagents, formation of these complex targets can be achieved in just three catalytic transformations with high levels of stereocontrol.

State-of-the-art quantum simulations predict that solvent molecules may partner with a solute in solution to form stable chemically distinct coordination species that interconvert from one to another. The solvent would thus be directly implicated in chemical reactions.

Specific forms of nitrogen doping can endow carbon-based metal-free materials with electrocatalytic activity. Now, introducing sp-hybridized nitrogen atoms into some acetylenic sites of ultra-thin graphdiyne — a highly π-conjugated lamellar carbon allotrope — has led to excellent oxygen reduction reaction activity.

Potassium channels rapidly move K⁺ ions across cell membranes while blocking Na⁺, but how these two effects are achieved simultaneously has remained unclear. Now, extensive molecular simulations show a single mechanism that features fully dehydrated ions can explain both rapid transport and impeccable selectivity.

Enzymes can perform various biological functions because of their delicately and precisely organized structures. Now, simple inorganic nanoparticles with a rationally designed recognition capability can mimic restriction enzymes and selectively cut specific DNA sequences.

A new pyrrolysyl-tRNA synthetase/^PyltRNA (PylRS/^PyltRNA) pair that is mutually orthogonal to existing PylRS/^PyltRNA pairs has now been discovered and optimized. This system could enable the site-specific incorporation of a greater number of distinct non-canonical amino acids into a protein.

Sodium chloride phases with unconventional non-1:1 stoichiometries are known to exist under high-pressure conditions. Now, Na₂Cl and Na₃Cl two-dimensional crystals have been obtained under ambient conditions, on graphene surfaces, from dilute solutions.

Certain drug targets have been deemed undruggable because of the difficulty in finding pharmacologically useful inhibitors. Now, two teams have developed exciting technologies for the creation of diverse collections of macrocyclic molecules and have demonstrated their usefulness for discovering macrocyclic inhibitors.