Articles in 2020

Interactions between two bodies that are both attractive and repulsive — such as predators chasing prey — are common in nature. Similar chasing behaviour has now been engineered in self-propelling microdroplets and controlled through fundamental physical and chemical mechanisms.

Interactions that generate directed movement in response to a chemical stimulus occur in nature but have been difficult to realize in synthetic systems. Now, it has been shown that asymmetric micelle-mediated exchange of haloalkanes can be used to create tunable chasing interactions between chemically distinct microdroplets. Collective interactions lead to the formation of droplet assemblies with emergent self-organization and collective behaviours.

Nature successfully uses supramolecular assemblies for efficient and robust solar energy harvesting; however, mimicking such material systems for applications in optoelectronic devices has been hampered by stability issues such as the fragility of the supramolecular structures used and the delicate nature of Frenkel excitons. Now, enabled by tunable cage-like scaffolds, stable supramolecular light-harvesting nanotubes have been composed that are robust even under heat stress.

Synthetic oligo-/polyynes with unprecedented length are used to model the elusive carbon allotrope carbyne. Spectroscopic and physical analyses show that endgroups influence the properties of shorter derivatives, but these effects predictably diminish in longer molecules. Molecular symmetry documents the evolution of characteristics from oligoynes to polyynes and offers predictions for the D_∞h structure of carbyne.

Layered COFs are attractive precursors for two-dimensional materials but they are difficult to cleave into mono- or few-layer sheets. Pseudorotaxane moieties have now been embedded into layered COFs to facilitate their cleavage into sheets of uniform thickness. Crown-ether macrocycles within the COF backbone bind to ionic viologen guests, leading to electrostatic repulsion between layers.

If you feel like shifting your attention away from what’s happening here on planet Earth in 2020 for a moment, join Bruce C. Gibb on a tour through the chemistry of the largest planet in the Solar System.

Ayanna Jones, Samantha Mensah and Devin Swiner, three of the #BlackInChem co-founders, talk to Nature Chemistry about the origins, goals, initiatives and joy of this movement.

It’s generally assumed that primitive forms of cellular life arose from nucleic acids and peptides compartmentalized within vesicles — all underpinned by a non-enzymatic protometabolism. Three studies now provide new insights into the ancient chemistry that may have supported early biology.

It is far from certain how simple chemical reactions became interconnected networks that gave rise to life on early Earth. Exploring the possible ways in which this could have occurred is an active area of research and a collection of articles in this issue consider what chemical steps may have been taken on the path towards life as we know it today.

The #ScienceTwitter community was recently treated to a virtual campaign under the hashtags #BlackInChem and #BlackChemistsWeek. This event highlighted past and present contributions from Black people in the field and offered unique opportunities for networking, mentorship, and recognition, say Abraham Beyene and Priera Panescu.

The manner in which adjacent sheets stack in layered covalent organic frameworks largely influences their material properties, including chemical stability, crystallinity and porosity. The layer stacking of a COF has now been probed locally, showing disorder that is not detected through long-range characterization.

Life requires a constant supply of energy, but the energy sources that drove the transition from prebiotic chemistry to biochemistry on the early Earth are unknown. Now, a potentially prebiotic chemical activating reagent has been shown to enable the synthesis, in aqueous conditions and catalysed by small molecules, of peptides, peptidyl–RNAs, RNA oligomers and primordial phospholipids.

Labelling proteins at internal sites holds promise for generating novel protein conjugates in a programmable fashion. Now, a chemoenzymatic approach, dubbed LACE, enables the site-specific modification of recombinant proteins that contain a short genetically encoded tag.

Conducting high-resolution, multiplexed imaging in living mammals is challenging because of considerable scattering and autofluorescence in tissue at visible and near-infrared wavelengths. Now, real-time, non-invasive multicolour imaging experiments in live animals have been achieved through the design of optical contrast agents for the shortwave infrared (SWIR, 1,000–2,000 nm) region and the introduction of excitation multiplexing with single-channel SWIR detection.

The past decade has seen unprecedented growth in the development of chemical methods that proceed by mechanisms involving radical intermediates, but controlling absolute stereochemistry has been a longstanding challenge in this area. This Review Article examines how attractive non-covalent interactions between a chiral catalyst and the substrate can exert enantiocontrol in radical reactions.

Silyl-substituted silicon–carbonyl complexes that are stable at room temperature have been prepared by exposure of highly reactive bis(silyl)silylenes to carbon monoxide. The compounds show structural features and reactivity that are reminiscent of their ubiquitous transition-metal–carbonyl counterparts, including π-backbonding and ligand liberation as well as substitution and functionalization reactions.

The controllable functionalization of graphene at the molecular level may prove useful for graphene-based electronics, but is difficult to do in a precise fashion. Now it has been shown that a photocycloaddition reaction between a hydrogen-bonded network of maleimide-derived molecules and single-layer graphene can produce a functionalized array with long-range order.

It is unclear how phospholipid membranes formed on the early Earth, as modern cells synthesize the phospholipid constituents of their membranes enzymatically. Now, a combination of ion pairing and self-assembly has enabled transacylation of lysophospholipids with acyl donors in water, affording a variety of membrane-forming natural diacylphospholipids in high yields.