Articles in 2009

Many lab-on-a-chip applications use microarrays for the high-throughput screening of a range of materials, including biomolecules such as DNA and proteins, as well as living cells. To address some of the limitations of traditional printed microarrays, researchers have now developed robust hydrogel-based systems with thiol-ene chemistry that enables different covalent attachment strategies to be implemented in an orthogonal fashion.

Although molecular motors that ‘walk’ along tracks are common in biological systems, the only artificial analogues reported so far have been made from DNA. It has now been shown, however, that a synthetic small molecule with two ‘feet’ can take steps along a molecular track, and that the direction of movement can be biased under certain conditions.

A phosphine catalyses the formation of multiple rings and stereocentres in a single step from a simple linear precursor.

Tethering a nickel complex to carbon nanotubes creates an effective catalyst for fuel cells.

A simple fluorescence quenching method can be used to visualize graphene.

Nature's enzymes are remarkably efficient at catalysing highly specific reactions with extraordinary selectivity. The ability to design enzymes for any desired reaction is a huge challenge. Here, the advances in the development of artificial enzymes are discussed with a particular focus on the computational advances that bring this challenge closer to reality.

The construction and operation of interlocked molecular machines often rely on the mutual recognition of different building blocks through a range of non-covalent interactions. Researchers have now shown that the versatility of bipyridinium systems can be increased by taking advantage of the complexes formed between their radical cations; with this approach they have been able to make electrochemically switchable bi- and tristable rotaxanes.

Chemists have very few tools at their disposal for controlling synthetic processes under physiological conditions. Now, a monomer has been prepared that oligomerizes in living cells under the control of various triggers (pH change, disulfide reduction and enzymatic cleavage), showing promise for imaging or therapeutic applications.

Two abundant feedstocks, dinitrogen and carbon monoxide, have the strongest bonds in chemistry, so breaking them is a significant challenge. An organometallic hafnium compound has now been shown to induce nitrogen cleavage on addition of carbon monoxide, with simultaneous assembly of new nitrogen–carbon and carbon–carbon bonds.

Electron tomography has revealed the interior structure of a calcite–agarose composite material.

Charge transfer in a donor–bridge–acceptor ensemble is shown to be affected by exciting the vibrational modes of the hydrogen-bonded bridging groups.

The conversion of carbon dioxide into methanol has been achieved by a metal-free homogeneous process.

A cluster formed by calixarenes coordinated to a mixed metal manganese–gadolinium magnetic core has excited states that are populated at low temperature, and shows promise for magnetic refrigeration systems.

Unusual ozonide and adamantane motifs are essential for the activity of next-generation antimalarial drugs.

A molecular crystal shows extremely large anisotropic positive and negative thermal expansion.

The Nobel Prize in Chemistry for 2009 was awarded for research into the structure and function of the ribosome, sparking debate about its significance to chemists.