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Colloidal clathrate crystals self-assembled from hard polyhedral shapes in computer simulations are stabilized by entropy compartmentalization, whereby hosts and guests contribute unequally to the entropy. This creative solution to satisfying the laws of thermodynamics suggests new ways to make colloidal crystals with open cages and hierarchical host–guest structures.

Protein solutions can undergo liquid–liquid phase separation, by condensing into a dense phase that often resembles liquid droplets, which coexist with a dilute phase. Now it is shown that hydrophobic interactions, specifically at interfaces, can trigger a liquid–solid phase separation of a protein solution.

Clathrates—open crystals with a hierarchy of polyhedral cages—are mostly found in atomic and molecular systems. Now, it has been shown through Monte Carlo simulations that the formation of colloidal host–guest clathrates can be driven by entropy alone, through entropy compartmentalization.

A trivalent 4f cationic complex bearing two bis-silylamide ligands has been prepared that displays slow magnetic relaxation. The bulky ligands and weakly coordinating anion stabilize the pseudotrigonal geometry necessary to elicit strong ground-state magnetic anisotropy in this axially coordinated Yb(III) complex with well-localized charges.

Dipolar cycloadditions are excellent processes for generating heterocyclic systems from simple starting materials, but arenes as dipolarophiles have not been extensively explored. Now, the intramolecular dipolar cycloaddition of aromatic rings has been achieved using in situ generated diazoalkenes to produce bicyclic or tricyclic heterocycles.

1,3-Dipolar cycloadditions are well-known transformations in organic synthesis. However, the reactivity of benzene rings in these processes is underexplored. In situ-generated diazoalkenes have now been shown to undergo intramolecular 1,3-dipolar cycloadditions with aromatic rings. The transformation results in an unaromatized benzene ring that enables the synthesis of functionalized heterocycles.

Cellular membranes contain numerous lipids, and efforts to understand the biological functions of individual lipids demand approaches for controlled modulation of membrane composition in situ. Now, click chemistry-based directed evolution of a microbial phospholipase within mammalian cells affords an editor for optogenetic, targeted modification of phospholipids in cell membranes.

In vitro screening of a ribosomally synthesized macrocyclic peptide library containing cyclic γ^2,4-amino acids (cγAA) afforded the discovery of potent inhibitors of the SARS-CoV-2 main protease (M^pro). A co-crystal structure revealed the contribution of this cγAA to M^pro binding and the proteolytic stability of these macrocycles.

Electronic spin influences chemistry profoundly, but its role in surface chemistry is poorly established. Now the spin-dependent reaction probabilities of oxygen atoms with a graphite surface have been studied. Molecular dynamics simulations help elucidate the mechanism for spin-flipping, which is observed to occur with low probability in surface scattering experiments.

Getting started at a new institution and building a research programme can be an exciting period, but there is much to do in a short space of time. Shira Joudan reflects on her first month as an assistant professor, discussing the stresses of setting up a new lab and how it’s easier with a little help from your (new) friends.

The diverse site-selective functionalization, including multi-functionalization, of C=C double bonds and C(sp³)–H bonds remains a largely unmet challenge. Now, a palladium-catalysed aerobic oxidative method has been developed for the multi-site programmable functionalization of terminal olefins via a strategy that controls the reaction sequence between alkene isomerization and oxidative functionalization.

In situ chirality identification for single-molecule systems is not a straightforward task. Now, real-time chirality identification during a Michael addition reaction has been realized by continuous measurements of spin-polarized currents through a single-molecule junction, providing a promising method for studying symmetry-breaking reactions.

Catenanes that are chiral owing to the relative orientation of their rings have always been referred to as ‘topologically chiral’. It is now shown that although in specific cases the stereochemistry is a topological property of the structure, the underlying stereogenic unit itself is not inherently topological in nature.

Catenanes are topologically non-trivial and, perhaps for this reason, molecules composed of two oriented rings have always simply been referred to as ‘topologically chiral’. Now it has been shown that the same stereogenic unit can arise in systems whose stereochemistry is Euclidean, suggesting a need to rethink this fundamental form of mechanical chirality.

The metallophilic interaction between cyclometalated palladium complexes can facilitate supramolecular nanostructure formation in living mice, providing a phototoxic prodrug with a long circulation time and high tumour-targeting efficiency. Upon green light irradiation, this palladium-based drug destroys solid tumours, leaving non-irradiated organs intact.

Organisms that glow are perhaps eerie. Vadim Viviani ponders on the luciferin–luciferase systems responsible for their intriguing bioluminescence.

Catalytic enantioselective approaches to access chiral organophosphorus compounds are rare. A two-stage catalytic strategy for the synthesis of diverse enantioenriched P(V) compounds has now been developed: a bifunctional iminophosphorane superbase enables enantioselective nucleophilic desymmetrization, followed by downstream enantiospecific diversification of the resulting intermediate by substitution with medicinally relevant O-, N- and S-based nucleophiles.

The inability to access well-defined polysaccharides in sufficient quantities has hampered our understanding of their structure–function relationships. Now it has been shown that native precision polysaccharides can be readily prepared via living polymerization of 1,6-anhydrosugars. The obtained polymers display excellent chemical recyclability, suggesting their potential utility as a class of sustainable materials.