Articles in 2020

Acyl fluorides are useful synthetic intermediates, but their preparation may involve toxic or unstable reagents. Here the authors use 2-(difluoromethoxy)-5-nitropyridine as a bench-stable reagent for the one pot palladium-catalysed conversion of aryl and vinyl iodides to the corresponding acyl fluorides.

The catalytic mechanism in non-oxidative methane coupling becomes complicated at high temperatures, making informed catalyst design challenging. Here, microkinetic modelling and experiments on a single-atom iron catalyst show how optimizing the reaction conditions can increase the C2 hydrocarbon yield.

Hyperpolarised water is an attractive alternative to metal-containing contrast agents in magnetic resonance imaging, but generating usefully persistent hyperpolarised water protons is challenging. Here dissolution dynamic nuclear polarisation using UV-generated radicals is used to obtain substantial water signal enhancement.

Ionic liquids are used as solvents in biocatalysis but how they interact with the structures of proteins is imperfectly understood. Here the effect of three common ionic liquids on the structure of green fluorescent protein is studied using a suite of experimental techniques, finding a complex relationship which is poorly captured by any single technique.

The conformational flexibility of monoribonucleotides can make interpreting their vibrational spectra challenging. Here a combination of classical and ab initio molecular dynamics is used to calculate the contributions of different monoribonucleotide conformers to experimental Raman spectra.

Organic molecules that exhibit thermally activated delayed fluorescence allow for high efficiencies in OLEDs, but their operational stability remains a challenge to their commercialization. Here the molecular factors that govern the stability of various dyads based on a cycloamino donor–acceptor platform are studied.

Hypoxia-inducible factor (FIH) is an oxygenase which post-translationally hydroxylates proteins and is implicated in a range of biological processes. Here a wide substrate tolerance for FIH is demonstrated, including for d-amino acids, where double hydroxylation of d-leucine is observed.

Diastereoselective cyclisation of heteroatom-substituted enynes offers a valuable route to bioactive heterocycles. Here, a diastereodivergent nickel-catalysed cyclisation of heteroenynes offers access to diastereomers of 1,3- and 1,4-hydroalkenylation products, controlled by the choice of substituents.

Molecular crowding such as that which may occur in model protocells is known to reduce the rate and fidelity of RNA replication. Here diffusion NMR and NMR relaxation studies of RNA monomers under crowded conditions show that purines stack more efficiently than pyrimidines, reducing their availability for polymerization.

The mechanism of formation of H₃⁺ cations during double ionisation of methanol is debated. Here a combination of spectroscopic and molecular dynamics studies support a mechanism involving abstraction of a proton from the double cation by roaming neutral hydrogen molecules within 100 femtoseconds.

Dienes are useful reagents for cross-couplings in the synthesis of unsaturated natural products, but decarboxylative Heck reactions of dienes are limited by facile E/Z isomerism. Here configurationally stable divinyldicarboxylic acid is used as a coupling reagent in which the carboxylates direct the Heck reaction prior to decarboxylation.

Dilute alloy nanoparticles are a promising class of heterogeneous catalysts, but how their composition and structure affects performance is imperfectly understood. Here dilute PdAu catalysts are shown to be highly dynamic, which enables systematic tuning of their structure and composition to maintain an active state.

Enantioselective dicarbofunctionalization of tethered alkenes typically relies on facially selective arylmetalation as a key step. Here, a nickel-catalyzed reductive carboacylation of alkenes and alkyl iodides which features acylnickelation as the enantiodetermining step is reported.

Single-atom heterogeneous catalysts are widely studied, but few examples are known which promote carbon–carbon bond formation. Here single palladium atoms supported by crystalline ZnO-ZrO₂ catalyse Suzuki–Miyaura couplings.

The restrained electrostatic potential (RESP) is a widely used method for assigning partial charges to organic molecules for molecular dynamics simulations, but it imperfectly accounts for self-polarization in solution. Here, RESP is updated by co-optimizing the polarity of the charges it generates, along with atomic Lennard-Jones parameters, to yield an improved model of non-bonded interactions.

The lower decomposition barriers of cyclo-N₆ anions hinder their application as high-energy-density materials. Here, first-principles calculations reveal that enhancing the covalent component of the interaction between cyclo-N₆ anions and cations can effectively improve stability at high pressure.

Multinuclear metal complexes are common motifs in metalloenzymes and hold promising applications in homogeneous catalysis. Here an iodide-bridged binuclear palladium complex improves the efficiency of C-H nitrosation/annulation reactions through a trans effect.

Octa-coordinated complexes or ions have a bond order of seven, yet they accommodate eight lone-pairs of ligands. Here the Jellium model is demonstrated to be an appropriate description of the valence bonding structures of M(CO)₈ species, where each coordinative bond contains 7/8ths of the bonding orbitals and 1/8th non-bonding orbitals.

The efficiency of perovskite/silicon tandem solar cells is affected by silicon surface texture, however fabrication processes in solution limit surface studies. Here a perovskite layer on textured silicon is formed through a dry two-step conversion process with lead oxide sputtering and direct contact with methyl ammonium iodide.

The biochemical phosphate cycle is dependent on interfacial reactions between humic acid and iron-bearing minerals, but the role of humic acid remains unclear. Here the authors study the reaction of siderite with humic acid and its influence on phosphate adsorption.