Articles in 2009

Can philosophy make worthwhile contributions to science? Eric Scerri thinks it can, and looks at what it has brought to the table for chemistry.

Chemists are like detectives: they like to know 'whodunit' during a catalytic reaction. Combining advanced electron microscopy with intelligent molecular design has now provided strong evidence for the presence of a highly active site within a complex catalytic solid.

Shining circularly polarized light into a suspension of racemic amino-acid-derivative crystals in a saturated solution and then grinding them results in enantiomerically pure crystals. This evolution is shown to be directed by an unknown chiral product.

The conformational structure of a molecule can have important effects on its interactions and properties, but studying such effects is made difficult by the challenge of separating different conformers. Their spatial separation has now been achieved using an electric field — allowing the possibility of isomer-specific studies.

Magnesium is commonly found in rocks and sea water as well as living organisms. Paul Knochel relates how this element has also sparked a great deal of interest among chemists.

Proton-conducting solids are crucial components in a variety of electrochemical and energy-conversion devices. A porous metal–organic framework loaded with guest molecules displays both proton-conducting and gas-tight properties, affirming its potential as a fuel cell membrane.

In spite of the many functions of copper proteins within biology, those that contain a single copper ion can be divided into two classes, based in part on their spectroscopic properties. An artificial 'type 0' protein combines some properties of both, and may offer a route to stable catalytic processes.

The formation of a phosphine oxide with its strong P=O bond is the driving force for the classical Wittig reaction, but is wasteful and can pose problems during purification. A new development allowing the use of catalytic phosphorus reagents promises to clean up olefination chemistry.

New web-based models of scholarly communication have made a significant impact in some scientific disciplines, but chemistry is not one of them. What has prevented the widespread adoption of these developments by chemists — and what are the prospects for adoption over time?

Many synthetic processes rely on the ability to selectively couple oxygenated molecules. Here a study of low-temperature selective cross-coupling of aldehydes with methanol on a gold surface is presented. The results allow the construction of a mechanistic model for such coupling reactions that will be applicable under a wide range of reaction conditions.

Combining the benefits of homogeneous and heterogeneous processes may lead to important advances in catalysis. This has now been achieved using selectively oxidized and supported electrophilic platinum nanoparticles that catalyse a range of π-bond activation reactions previously only catalysed homogeneously.

Proton hydrates that have an extensive charge delocalization can aggregate into proton wires within carborane nanochannels.

The ultrafast protonation of bicarbonate by a photoacid gives a glimpse of the elusive aqueous carbonic acid species.

A protein cage acts as a mould for growing coordination polymers with precise control over the size of the resulting particles.

Encapsulating guest molecules inside host structures ranging from soft, flexible enzymes to rigid, porous zeolites has led to developments in many areas, including catalysis, sensing and separation. This Review highlights how metal–organic frameworks — materials formed by linking metal centres with organic ligands — can combine softness with regularity to produce dynamic, yet crystalline, structures that may prove useful for a range of applications.

Both hydrogen and xenon form unusual phases at very high pressures. Researchers have now observed that an unexpectedly stable compound forms when a hydrogen-rich mixture of the two gases is subjected to pressures in the gigapascal range. Xenon dimers and other unusual bonding states are revealed in this compound, which is stable to megabar pressures.

When making nanoparticles it is often desirable to produce samples in which there is little variation in the size of the structures that are formed. Hollow self-assembled metal–organic cages have now been shown to be effective templates for the preparation of monodisperse silica nanoparticles, and may also prove useful for the controlled synthesis of nanoparticles from other materials.

Encapsulating arsenic- and platinum-based drugs together in the same liposome carrier has increased their efficiency for targeted cancer treatment and stability.

A chemoinformatics approach, which defines drug targets by the molecules they interact with, allows the creation of a map that predicts many useful unanticipated interactions.