Articles in 2017

The analysis of complex (bio)molecules by NMR spectroscopy is often complicated by limitations in sensitivity. Now, it has been shown that ¹³C NMR signals are strongly enhanced in solution by resonant microwave irradiation of a nitroxide polarizer. This method exhibits up to one-thousand-fold improvements in sensitivity, which stands to greatly improve the detail with which small molecules and metabolites can be studied.

Cation–π interactions are critical for the adhesion proteins of marine organisms, yet the energetics of cation–π interactions in underwater environments remains uncharted. Nanoscale force measurements and NMR spectroscopy reveal that interfacial confinement fundamentally alters the energetics of cation–π mediated assembly.

The properties of discrete species can sometimes be improved by fixing them into extended materials. This strategy has now been applied to silver(I) chalcogenide/chalcogenolate clusters, resulting in a metal–organic framework with enhanced stability and fluorescent sensing capabilities. Crystallographic analysis allows precise structural determination of guest binding, which is responsible for both emission turn-off and multicoloured turn-on.

A scalable, one-pot, solution-based protocol for the controlled synthesis of uniform non-spherical block copolymer micelles is a desirable but challenging target. Now, a polymerization-induced crystallization-driven self-assembly process has been developed that offers facile access to 1D and platelet micelle morphologies and to near monodisperse cylinders of controlled length.

The secondary and tertiary structure of a protein has profound implications on function and catalysis. Now, both the secondary and tertiary structures of a synthetic polymer have been utilized to catalyse the polymerization of N-carboxyanhydrides. Both the folding of the resulting polypeptides into α-helices and their macromolecular organization dramatically enhance the polymerization rate.

Radical SAM enzymes are versatile enzymes catalysing chemically challenging reactions. Now, a radical SAM enzyme that post-translationally modifies ribosomally synthesized peptides to contain D-amino acids has been discovered in Bacillus subtilis, and its mechanism has been deciphered. These peptides, called epipeptides, efficiently inhibit bacterial growth.

Helium is generally recognized as being chemically inert. A thermodynamically stable compound of helium and sodium, Na₂He, has been predicted computationally and then synthesized at high pressure. It exists as an electride, where strongly localized electrons serve as anions located at the centre of Na₈ cubes.

Photoreceptors play an essential role in determining the fate of subsequent biological reactions, however, tracking their structural evolution on ultrafast timescales has been challenging. Now, photoactive yellow protein has been studied using time-domain Raman spectroscopy with sub-7-femtosecond pulses, revealing the ultrafast rearrangement of its hydrogen-bonding structure and also the structure of the first photocycle intermediate.

Planar molecules may break mirror symmetry when aligned on a surface, but both right- and left-handed forms will be created. Starting with a single-handed precursor, chiral adsorbates of planar hydrocarbons with a single handedness are formed in on-surface reactions.

A squaramide-based anion transporter has now been shown to cause changes in the lysosomal pH leading to impairment of lysosomal enzyme activity and disruption of autophagic processes. The study provides the first experimental evidence that synthetic ion transporters can both disrupt autophagy and induce apoptosis.

Amidation is one of the most widely utilized organic reactions for the synthesis of pharmaceuticals and functional materials. DATB, characterized by the B₃NO₂ heterocycle, proved to act as a superb catalyst for the direct amidation with a distinct mechanistic pathway, displaying broadened applicability to a wide range of substrates.

A cytocompatible controlled radical polymerization method has now been developed that initiates polymer synthesis directly on the surface of living cells. This method achieves significantly enhanced polymer grafting and enables active manipulation of cellular phenotypes.

A programmable model of membraneless organelles comprised of intrinsically disordered proteins (IDPs) containing sequences of low complexity has now been developed. The rules governing the assembly of archetypal IDPs into biologically inspired mixed, layered and size-controlled configurations provides a new means for understanding intracellular phase behaviour of IDPs.

From grand challenges of nineteenth century chemistry to powerful technology in small packages, Brett F. Thornton and Shawn C. Burdette explain why neodymium is the twin element discovered twice by two Carls.

Strong interactions between oxide supports and catalytic metal particles can lead to inhibitive oxide layers forming over the active metal catalyst. Now, adsorbate-induced metal–support interactions have been shown to lead to a porous overlayer in the Rh/TiO₂ system that tunes catalyst activity, improving its selectivity for the partial reduction of CO₂.

The chemical universe is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. Bruce Gibb reminds us that it's somewhat messy too, and so we succeed by recognizing the limits of our knowledge.

Attempts to build lifelike synthetic protocells must consider extracellular influences in order to accurately reflect the behaviours and characteristics of real ecosystems. Now, this concept has been demonstrated by the synthesis of a community of protocells in which one cell type preys upon another.

A chiral ammonium salt mediates a dynamic kinetic resolution of racemic α-aryl ketones by atropselective O-alkylation. Oxidation with DDQ gives access to C₂-symmetric and non-symmetric BINOL derivatives in high yields and with high enantioselectivity.

Mono-iron hydrogenase promotes the heterolytic cleavage of H₂ and subsequent hydride transfer to its organic substrate, H₄MPT⁺, which serves as a CO₂ ‘carrier’ in methanogenic pathways. Now, using an anthracene-scaffold-based approach, a synthetic model featuring enzyme-like Fe-C,N,S facial coordination has been developed. The model complex enables the bidirectional activity of H₂ activation and evolution.

The first example of an asymmetric silver-catalysed intermolecular bromotrifluoromethoxylation of alkenes has been described with trifluoromethyl aryl sulfonate as a new trifluoromethoxylation reagent. This reaction is operationally simple, scalable and proceeds under mild reaction conditions, which can be applied to the late-stage trifluoromethoxylation of complex small molecules.