Volume 4 Issue 6, June 2012

Proton conduction in both water and other hydrogen-bonded liquids occurs through successive proton transfers along the hydrogen-bond network. But first-principles simulations have revealed that the mechanism by which this occurs in orthophosphoric acid has some unusual features.

Flow chemistry has grown in stature as a technique with the potential to deliver synthetic complexity with assembly-line-like efficiency. Application of flow technology to the front-line antimalarial drug artemisinin promises to revolutionalize treatment.

Previous approaches to the development of self-repairing polymeric materials have required either the input of external energy or the use of a healing agent. Now, a new type of elastomer, in which hard/soft phase-separation occurs at the nanoscale, displays efficient and entirely autonomic self-repair through reversible hydrogen bonding.

The behaviour of di-selenol enzyme mimics indicates that a halogen bond between selenium and iodine, and a chalcogen interaction between the two selenium atoms, play an important role in the activation of thyroid hormones.

Supramolecular catalysts that combine an anionic chiral scaffold, a cationic coordinating structure and a metal centre have been shown to be highly effective for asymmetric synthesis. The success opens a new avenue for the design of new catalysts with a wide variety of chiral environments.

Sensing neuronal activity using fluorescence has many potential advantages over current methods. Now, by taking advantage of photoinduced electron transfer, fluorescent sensors have been developed that allow high-fidelity recording of neural signals in real time.

A dihydroboration–amination sequence provides a step-economical route to indolizidine alkaloids — a common structure in bioactive natural products.

Thiolate-protected gold surfaces and interfaces are archetypal systems in various fields of current research in nanoscience, materials science, inorganic chemistry and surface science. Examples include self-assembled monolayers of organic molecules on gold, passivated gold nanoclusters and molecule–gold junctions. This Review discusses recent experimental and theoretical breakthroughs that highlight common features of gold-sulfur bonding in these systems.

The dynamics of mechanically interlocked molecules such as catenanes and rotaxanes have been studied in solution as examples of rudimentary molecular switches and machines. A metal–organic framework with a [2]rotaxane as a building block demonstrates that such dynamic processes can also operate inside a solid-state material.

Proton transport in phosphate-based systems is important in biology and clean energy technologies, and phosphoric acid, being the best known intrinsic proton conductor, represents an important model. Ab initio molecular dynamics simulations now reveal that the interplay between extended, polarized, hydrogen-bonded chains and a frustrated hydrogen-bond network gives rise to the high conductivity in liquid phosphoric acid.

Polymer materials that could spontaneously heal like tissues in living systems would significantly improve the safety, lifetime, energy efficiency and environmental impact of man-made materials. Now, a general multiphase design of autonomous self-healing elastomeric materials that do not require the input of external energy or healing agents is reported.

Rather than create a chiral catalyst by combining a chiral ligand with a metal, here an achiral phosphine ligand endowed with a cationic ammonium group is ion-paired with a chiral binaphtholate. A palladium catalyst based on this strategy is shown to be effective for highly enantioselective allylic alkylation of α-nitrocarboxylates.

Substituted aspartic acids are highly valuable as tools for biological research and as chiral building blocks for pharmaceuticals. Here, engineering of the enzyme methylaspartate ammonia lyase to accept a large variety of substituted amines and fumarates and catalyse the asymmetric synthesis of aspartic acid derivatives is described.

Triarylamine derivatives in solution have been self-assembled into organic nanowires between two electrodes, under white-light irradiation and in the presence of a voltage. The resulting fibres possess a very high electric conductivity as well as a metallic behaviour when cooled down to a temperature of 1.5 K.

Nature synthesizes proteins and nucleic acids by polymerization methods that use well-regulated and segregated templates. Now, synthetic block-copolymer templates have been designed to assemble in a biomimetic fashion to segregate, and thus control, the synthetic radical polymerization of complementary nucleobase-containing vinyl monomers, to yield high-molecular-weight, low-polydispersity polymer chains.

Copper and bipyridine (bpy) self-assemble in aqueous solutions at high pH into an active electrocatalyst for the oxidation of water to O₂, one of the great challenges in energy catalysis. These solutions contain primarily (bpy)Cu(OH)₂, and are robust and active catalysts, albeit at high overpotentials.

Acyclic cucurbituril-type molecular containers have been found to increase the solubility of insoluble pharmaceutical agents in water by up to 2,750-fold. In vitro and in vivo toxicology studies suggest that the containers are well tolerated, and paclitaxel solubilized in this manner efficiently kills HeLa and SK-OV-3 cancer cells.

Many chemical elements behave quite differently depending on the compound they are found in, but Matt Rattley argues that bromine does so in a particularly striking manner.