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This week The Alchemist learns how helium ions could soon displace electrons as the medium of choice in scanning microscopy allowing much clearer 3D images of nanoscopic objects to be obtained. We also hear of the plight of British rail passengers in the fall, when leaves on the line accompanies something not akin to mellow fruitfulness as trains that don't stick cause delays. Speaking of the big chill, xenon atoms cooled to close to absolute zero have been shown, using NMR spectroscopy, to display a new fundamental phenomenon that is a physical mashup between Newtonian mechanics in the form of chaos with the non-classical theory of quantum mechanics. In the world of catalysts, a robust, porous solid has been shown to act as a reaction flask for single crystal to single crystal reactions even with bulky reagents. While in biomedicine, the MMR hoax is perhaps finally laid to rest thanks to yet one more study. Finally, the American Chemical Society reveals a new landmark this week in the form of emulsion technology that led to a revolution in home improvements.

Scientists at the National Institute of Standards and Technology (NIST) are testing a helium ion microscope to the extremes of its capabilities to see whether it could cope with the demands of nanotechnology studies of importance to the semiconductor and nanomanufacturing industries. The new microscope uses helium ions, instead of electrons, to produce an image with greater depth of field than the scanning electron microscope, higher resolution images and higher contrast are also possible despite helium ions being far larger than electrons. "Ions have larger mass but a shorter wavelength than electrons," explains Andras Vladar, SEM project leader in NIST's Nanoscale-Metrology Group. Test images of a silicon crystal appear almost three-dimensional and reveal details smaller than a nanometer, he adds.

The daily commute for rail passengers can be an uncomfortable experience at the best of times in the UK, but in the autumn, one excuse is often heard from the train companies explaining delays - leaves on the line. It sounds such a weak excuse, how could a few fallen leaves delay the vast bulk of a train? Well, researchers Gordana Vasic and Francis Franklin of the University of Newcastle upon Tyne, UK, working with colleagues in Australia and Serbia, explain the issue with chemistry and a little meteorology. A thin, greasy film of dead leaves can stick to rails causing low adhesion between wheels and track, they say, which not only leads to safety problems with the possibility of collisions but also causes much more wear and tear on the rolling stock. They have carried out tests that demonstrate that friction falls dramatically regardless of the presence of leaves, but on a typical morning during Keats' "season of mists and mellow fruitfulness" dampness combines with nocturnal iron oxidation (rust) and a greasy coating of wet leaves to produce a surface so slippery that no adhesion between train and track is possible.

A spectroscopic study of chilled xenon atoms has uncovered a possible link between the classical world of chaotic behavior, which is essentially based on Newtonian mechanics and the sub-atomic constituency of the quantum world. Nuclear magnetic resonance spectroscopy has been used by Brian Saam and colleagues at the University of Utah's College of Science, USA, to investigate predictions about spin alignments made earlier by colleague Boris Fine of the University of Heidelberg, Germany, and his colleagues. The work shows a fundamental new physical phenomenon but could also have practical relevance for the development of xenon as a powerful contrast agent for medical magnetic resonance imaging (MRI).

A novel porous material synthesized by chemists in Japan acts as what they describe as a single-crystal reaction flask. Makoto Fujita and colleagues developed the material from the reaction of a triazine ligand with and zinc iodide in the presence of a 2-aminotriphenylene. They explain that the material crystallizes into a robust network with large pores into which even bulky chemicals can fit. With reactive groups, such as amino groups, protruding into the pores, dipping the material into a solution containing desired reactants brings them all together within the pores where they can react smoothly. As product forms, the crystal structure changes, but can be monitored throughout using X-ray diffraction.

Laying to rest once and for all the hoax that was the MMR-autism link, a case-controlled study of children with autism and gastrointestinal disturbances shows that the presence of measles virus RNA was no more likely in those children than in children with only gastrointestinal disturbances. Furthermore, the research by the US Centers for Disease Control and Prevention found that gastrointestinal symptoms and autism onset were unrelated to MMR vaccine timing in more than 100 children. In 1998, an unreviewed report by UK researcher Andrew Wakefield claimed a connection between the presence of measles virus RNA in intestinal tissue from just 12 children with autism spectrum disorders and gastrointestinal disturbances, which led to serious public concern over the safety of MMR vaccine. With the link revealed as nothing but a hoax by this and much other research, Wakefield now may face disciplinary action by the UK's General Medical Council.

A. Prasanna "AP" de Silva is announced winner of the Royal Society of Chemistry's Sensors Award for 2008. de Silva is Chair of Organic Chemistry at Queen's University Belfast, UK. His research which focuses on molecular logic gates and most recently "intelligent" molecules is at the heart of a diagnostics system, the market-leading OPTI point-of-care blood gas/electrolyte analyzer, which has had sales amounting to $50m globally so far. The award, sponsored by GE Healthcare, is given twice yearly for chemical excellence and input into the design of novel sensors or novel applications of existing sensors.