Articles in 2017

Geng Deng relates how terbium, a garden-variety lanthanide, has found its way into our daily lives owing to its green phosphorescence.

Michelle Francl muses on fantastic beasts of chemistry and why we try to find them.

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.

Given its ubiquity, the importance of understanding the properties of water cannot be understated. Now, stemming from discussions at a National Science Foundation-supported workshop, this Review Article highlights where there is latent chemical space for potential collaborations between the physical and supramolecular communities, both of which are interested in how molecules interact with each other in water.

The ability to merge the photophysical properties of semiconductor quantum dots with those of well-understood and inexpensive molecular chromophores is important for the development of various emerging photonic and optoelectronic technologies. Now, 1-pyrenecarboxylic acid-functionalized CdSe quantum dots have been shown to undergo thermally activated delayed photoluminescence and display tunable photophysical properties.

Enzymes that form a metabolic pathway in which the product of one enzyme is the substrate for the next have now been shown to associate through a process of sequential, directed chemotactic movement. The extent of enzyme migration is proportional to the exposure time to the substrate gradient.

Peptides derived from non-ribosomal peptide synthetases (NRPS) are an important class of pharmaceutically relevant drugs. However, no general rules for the modification of NRPS or the generation of artificial NRPS are known. Now, a new strategy for the modification of NRPS has been developed that uses defined exchange units that are fused at specific positions connecting the condensation and adenylation domains.

Catalytic transformations that incorporate carbonyl functional groups in arene C–H bonds have remained limited, despite being attractive synthetic steps. Now, the intermolecular carbonylative coupling of a broad range of simple arenes into ketones has been developed. The reaction occurs through the palladium-catalysed generation of high-energy aroyl triflate electrophiles.

The direct arylation of C–H bonds is an attractive synthetic step, but the reductive elimination of an organometallic catalyst carrying the desired C–H and aryl functionalities has remained challenging. Now, this step has been achieved by first oxidizing the iridium centre of the catalyst, which facilitates the arylation of arene C–H bonds of a range of substrates.

An arene-anchored uranium(III) complex that facilitates the electrocatalytic formation of H₂ from H₂O has now been shown to involve redox-cooperativity between the uranium centre and its covalently bound mesitylene ligand. The oxidative addition of H₂O to the uranium catalyst is a concerted two-electron reaction — atypical for f-block metals.

Selectively targeting native amino acids for late-stage protein modification is a significant challenge, but now it has been shown that photoredox catalysis can be used to specifically target protein C-termini toward decarboxylative-alkylation with Michael acceptors. This technology harnesses innate differences in side-chain oxidation potentials to select between the various functional groups typical among proteins in order to form a single modified product.

A centimetre-long string formed by the hierarchical self-assembly of a photoresponsive amphiphilic molecular motor — composed of 95 wt% of water — undergoes muscle-like contraction. Under irradiation, rotary motion at the molecular level is amplified through non-covalent interactions to sustain a fast macroscopic mechanical motion of large amplitude.

DNA–polymer conjugates are attractive materials that combine the programmability of nucleic acid assembly with polymer functionality. Now, through a DNA cube template, monodisperse polymer particles have been imprinted with several DNA strands in pre-designed orientations— each independently set and addressable. The resulting hybrid particles can further assemble into well-defined, non-centrosymmetric structures.

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.

Photosynthesis uses sunlight to oxidize or reduce reaction centres multiple times and prepare them for multiple-electron-transfer reactions. Now, it has been shown that a molecular proxy for a multiple-electron-transfer electrocatalyst can be oxidized twice by dye molecules when both are anchored to a mesoporous TiO₂ thin film and excited with low-intensity visible light.

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.