Volume 2 Issue 2, February 2010

Michelle Francl wonders why people almost inevitably draw scientists as men with weird hair and glasses, and why there is no such thing as a 'draw a lawyer' test.

A molecular 'walker' can be made to move up and down a molecular 'track' by alternately locking and unlocking the two different types of covalent bonds that join the two components together. By changing the conditions under which one of the bond-forming/bond-breaking processes occurs, a directional bias for walking can be achieved.

The use of conventional computers to calculate molecular properties is hindered by the exponential increase in computational cost on increasing the size of the molecules studied. Using quantum computers could be the solution and the initial steps are now being taken.

The stereochemical lability of cycloalkylzinc reagents combined with a large difference in reactivity between epimers has been exploited to form a wide variety of interesting organic compounds with both high yields and diastereoselectivities.

Quantum tunnelling can at times be the cause of kinetic isotope effects, and in these cases conventional wisdom has been that molecules with isotopes of larger mass will react more slowly. New calculations, however, predict that sometimes the reverse should be true.

Chemical reactions of fullerenes and metallofullerenes lined up inside single-walled carbon nanotubes can be monitored at the atomic scale inside an aberration-corrected transmission electron microscope.

Yttrium-based catalysts can be used to stitch together two different lactone monomers in an alternating fashion to produce polyesters with well-defined primary structures. The ability to control the sequence of building blocks in polymers with increasing levels of precision offers new opportunities for tailoring the properties of designer synthetic macromolecules.

An enzyme that is unusually tolerant of a truly broad range of substrates can catalyse aldol-type chemistry on sugars in which the various hydroxyl groups are protected. The new methodology combines some of the most important advantages of enzyme and small-molecule catalysis.

The formation of single-layer-thick molecular networks at metal surfaces is governed by the interplay between intermolecular and interfacial interactions. This Review highlights how, with films built by vacuum deposition, these interactions can be modulated to form substrates that may be useful as catalysts or templates for further deposition steps.

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.

Ready access to sugars in which the various hydroxyl groups are differentially protected will be of benefit in the production of vaccines, antibiotics and drugs. Here, a chemoenzymatic method that provides a direct route to such protected sugars is described.

Precise calculations of molecular properties from first-principles set great problems for large systems because their conventional computational cost increases exponentially with size. Quantum computing offers an alternative, and here the H₂ potential energy curve is calculated using the latest photonic quantum computer technology.

Silicon, like carbon, favours a four-coordinate geometry and this underpins the frameworks of the wide range of inorganic and organosilicon compounds, from silicate minerals to polysilanes. Although some pentavalent silicon compounds have already been reported, this work presents the first example where two five-coordinate silicon atoms are bonded to each other.

Well-resolved images of small molecules and their motions can be obtained with high-resolution transmission electron microscopy. It has now been shown that this technique can also be used to visualize individual chemical reactions involving the dimerization of fullerenes and metallo-fullerenes trapped inside carbon nanotubes by monitoring how the positions of their atoms change over time.

Highly diastereoselective Negishi cross-coupling reactions between 2-, 3- and 4-substituted cycloalkylzinc reagents and aryl iodides are described. In all cases, the thermodynamically most stable diastereomers of the cross-coupling products were obtained. NMR spectroscopy and density functional theory calculations were performed in order to rationalize the observed stereoselectivities.

The bulk properties of materials that lack long-range order have been widely studied, but their local structures remain difficult to elucidate. Now, using scanning tunnelling microscopy, researchers have been able to look more closely at the structural motifs of robust, two-dimensional glassy networks assembled through metal–ligand interactions.

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.

In the search for superheavy elements, element 112 was a stepping stone towards the 'islands of stability'. Sigurd Hofmann now relates the steps that led to its 'creation' and detection.