ChemWeb Newsletter

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The Alchemist gets the beat from a laser charger for cardiac pacemakers, this week, while finding out how to sculpt a molecular trap for nanoparticles. In biomedicine, scientists have homed in on the factors influencing the cancer enzyme and theoretical physical-organic chemistry, benzene reveals new secrets about its aromatic breathing. A major development for miners could help reduce the incidence of silicosis, we hear, and among this year's AAAS fellows are two chemists from New York University.

A team of researchers at the University of Connecticut and the US Air Force Research Laboratory has used DNA electrospinning to produce nanofibers that incorporate two different fluorescent dye molecules. The structure allows energy to be passed from one dye to the other efficiently - fluorescence resonance energy transfer (FRET). The color of the resulting fluorescence dependent on the ratio of the two dyes. Writing in Angewandte Chemie, Gregory Sotzing and colleagues explain how they have now produced full-spectrum white light using this approach. The emergence of this and similar devices from the fields of optoelectronics, photonics, and nanoscience could lead to optimized materials for electromagnetic energy manipulation.

Molecular cages have always been of interest to chemists. Now, a team at the University at Buffalo has sculpted a novel cage using bottlebrush molecules that form tiny, organic tubes whose interior walls carry a negative charge. Such a structure might selectively encapsulate positively charged particles. The team was also able to tailor the precise size of their traps too. Writing in the Journal of the American Chemical Society, they explain how they could capture particles just 2.8 nanometers in diameter, while excluding particles just 1.5 nanometers bigger. The team says their traps could be used in purification and separation processes for nanotechnology.

Researchers at the University of Montreal, Canada, have used novel microscopy techniques to visualize in living cells the behavior of the enzyme responsible for keeping cell replication in check, the enzyme telomerase. Telomerase snips the ends of the telomeres at the ends of DNA at each cell replication so that a cell can only replicate a limited number of times. In cancer this process goes awry allowing uncontrolled cell replication. Pascal Chartrand and colleagues have now homed in on precisely what happens when telomerase is active. They have now identified regulatory factors that restrain the activity of telomerase within a narrow time window when the cell is dividing. Such insights might ultimately allow medicinal chemists to target those factors or telomerase itself to block cancerous replication.

Friedrich Kekulé's apocryphal daydream of a tail-eating snake led him to the cyclic structure of the benzene molecule, the only way, he reasoned, that six carbon atoms and six hydrogen atoms could sit comfortably together and display the molecule's known properties. Chemists ever since have been fascinated by the benzene molecule whether the standalone compound or the ring embedded in millions of different compounds. However, it still continues to surprise and a new theoretical study by David Bean and Patrick Fowler of the University of Sheffield, UK, now reveals how the aromaticity of the molecule ebbs and flows as the ring breathes. Their discovery takes us another step closer to a full understanding of how aromaticity affects stability and the reactivity of the benzene ring.

A portable near-infrared detector can measure levels of silica in coal dust, according to Arthur Miller at the National Institute for Occupational Safety and Health, Spokane, and colleagues. The device could be useful in instigating appropriate protection for miners potentially exposed to silica, which can lead to the fatal condition silicosis through inhalation of microscopic particles of the substance. The device could be used to inform immediate adjustments to the mining process so reducing the risk of disease and death, Miller suggests.

Chemists Zlatko Bacic and Michael Ward of New York University have been selected by the American Association for the Advancement of Science (AAAS) as 2011 Fellows. Bacic, works in theoretical and computational chemistry, and was recognized for distinguished contributions in creating computer models of how small molecules interact, with a particular focus on clusters and behavior in tiny cavities. Ward was cited for distinguished contributions to solid state chemistry and materials science, for his service as an editor of the journal Chemistry of Materials, and for his role as director of two NSF-supported research centers.