The Alchemist Newsletter: Oct 12, 2012

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A simple approach to make p-xylene from ethylene could help the chemical industry reduce its dependency on crude oil by allowing natural gas or biogas supplies to act as a feedstock. Maurice Brookhart and colleagues at the University of North Carolina at Chapel Hill, USA, have developed a synthetic route from ethylene to the aromatic. First, they form a trimer from ethylene to generate a six-carbon intermediate, which, following dehydrogenation, undergoes a Diels–Alder reaction with an additional ethylene molecule to form 3,6-dimethylcyclohexene. Catalytic dehydrogenation of this with platinum over alumina yields a good supply of p-xylene with minimal by-products.

Restructuring the Chemical Industry One Reaction at a Time

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Physical chemists know only too well how anomalous the behavior of water can be. Now, researchers from the University of Twente, in the Netherlands, have chilled water droplets on a plate at -20 Celsius and taken snapshots of the freezing front as it travels up the droplets. Freezing took about 20 seconds and as the last liquid solidifies each ice drop develops a pointy tip. The vertical expansion of the ice, in combination with the confining effect of surface tension on the spherical cap of remaining liquid, leads to the point formation. Which as physical chemists will tell you is most likely to be due to the presence of the ubiquitous hydrogen bond network in water.

Freezing Water Droplets Form Sharp Ice Peaks

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Organic catalysts might facilitate the development of fuel cells, an essentially nineteenth century technology, into an alternative power system for applications in the twenty-first century. Scientists at Ume? University in Sweden writing in the journal ACS Nano have improved our understanding of how inexpensive organic catalysts, based on nitrogen-doped carbon nanotubes, might displace expensive catalysts based on nobel metals. The team has demonstrated that nitrogen defects can boost local catalytic activity in carbon nanotubes and that heat treatment can improve the activity of these defects still further. The team is also investigating related materials for artificial photosynthesis.

More efficient all-organic catalysts in fuel cells

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New clues as to how atmospheric aerosol particles "age" have been revealed by an international team of researchers. The team explains how aerosol particles are critical to atmospheric health and thus affect cloud formation, the Earth's albedo, weather patterns and ultimately climate. In the Muchachas [Multiple Chamber Aerosol Chemical Aging Experiments] project, the team has shown that aerosols comprising organic compounds are "aged" by the presence of hydroxyl radicals in the air. It is now essential that this factor is incorporated into the next-generation climate change models.

International research group shows that the aging of organic aerosols is caused by OH radicals

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A new drug for ovarian cancer could cut the number of doses needed for a chemotherapy regimen as well as potentially reducing the effects of drug resistance. The new class of cytotoxic agents, PACMA, emerged from screening of a 10,000 compound library by University of Southern California researchers. Currently, there are two types of drug to treat ovarian cancer, paclitaxel which inhibits microtubule disassembly and so blocks cell division and carboplatin which creates DNA crosslinks to kill cancer cells. PACMA31 irreversibly inhibits protein disulfide isomerase an enzyme that is over-expressed by ovarian cancer cells. The drug needs much pre-clinical testing before it can be trialed in women with the disease. However, its novel mode of action and lack of obvious toxicity in preliminary tests bodes well for the development of a new and effective cancer therapy.

USC Collaboration Leads to Publication in Proceedings of the National Academy of Sciences

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A $500,000 non-strings attached genius grant has been awarded by the MacArthur Fellowship to geochemist Terry Plank who develops chemical proxies to help improve our understanding of the deep earth and how to affects explosive volcanic activity at the surface. Columbia University's Plank stands tall alongside mathematician Maria Chudnovsky, novelist Junot Diaz, war correspondent David Finkel and filmmaker Natalia Almada. Plank is the daughter of two chemists and grew up fascinated by rocks and minerals, one might suggest that it was almost inevitable that she would be a genius geochemist.

Volcano Expert Wins MacArthur 'Genius Grant'

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