The Alchemist Newsletter: August 26, 2009

The Alchemist this week learns how fluorine chemistry is blooming, how to melt proteins, and how cholesterol is all about the good, the bad, and the oxy. Also this week, a technique borrowed from organic LED fabrication could lead to a new way to manufacture tiny inorganic LEDs for next generation displays, while a conductive flip has been observed with clusters of atoms close to absolute zero. Finally, the American Chemical Society announces this years previously unsung chemical heroes from across the industry.

back to top

Fluorine flowers

A simple and cost-effective way to add fluorine to various compounds, from pharmaceuticals to agrochemicals has been developed by Stephen Buchwald and colleagues at the Massachusetts Institute of Technology. About a fourth of all pharmaceuticals on the market now contain at least one fluorine atom, which not only improves efficacy and reduces side-effects but neatly side-steps patent expiries and certain regulatory hurdles. Buchwald and colleagues have identified conditions under which reductive elimination occurs to form new carbon-fluorine bonds in a catalytic process, a reaction that was missing from the chemist's synthetic repertoire until now.

New method for fluorinating compounds

back to top

Biological meltdown

Heating proteins usually causes them to denature and break down. They don't melt like other solids. Steven Mann and colleagues at Bristol University, England and at the Max Planck Institute of Colloids and Interfaces in Golm, Germany, have demonstrated that modifying the protein surface with a polymeric surfactant could overturn this received wisdom. They have successfully "liquefied" the protein ferritin, to a transparent, viscous red liquid that solidifies upon cooling to -50 Celsius. In the temperature range 30 to 37 Celsius, the modified protein is in the liquid crystal state. Mann hints that the research could have applications in biomedical research and sensor technology.

Molten Proteins

back to top

The good, the bad, and the oxy

Forget "good" cholesterol and "bad" cholesterol, according to research presented at the American Chemical Society's national meeting in August, it's the oxy form of cholesterol we should be concerned with when it comes to cardiovascular health. Total "bad" cholesterol, low-density lipoprotein cholesterol (LDL), and the heart-healthy high-density lipoprotein "good" cholesterol (HDL) are important health indicators explained Zhen-Yu Chen of the Chinese University of Hong Kong, but he says that medicine should recognize that the less well known oxycholesterol is also important and should not be ignored. "Our work demonstrated that oxycholesterol boosts total cholesterol levels and promotes atherosclerosis ["hardening of the arteries"] more than non-oxidized cholesterol," Chen says."

Little known type of cholesterol may pose the greatest heart disease risk

back to top

LED bulk

While organic light emitting diodes (OLEDs) are all the rage among gadget manufactures solid work in the area of inorganic LEDs has led to the development of semiconductor devices that could act as individual pixels in a display. John Rogers of the University of Illinois, Urbana-Champaign and colleagues have lifted the "simple" OLED fabrication technique, which involves layering materials, and applied it to their inorganic LEDs. The hope is that these lights could be eventually be produced en masse in parallel to act as the pixels of a display screen, rather than merely being used as a backlight source.

Producing tiny inorganic LEDs in bulk

back to top

Conductive flip

What happens when clusters of atoms flip from an electrically conducting state to an insulating one? Now, Cheng Chin of the University of Chicago and colleagues think they have an answer. His team have observed such a transition using super-cooled atoms to emulate the behavior of electrons. The atoms move a billion times slower than electrons but share several of their characteristics at close to absolute zero. Their experiments confirmed a prediction made in 2000 that atoms in the superfluid state, conducting, will experience very little repulsive force between each other and could be compressed. But, when a magnetic field was applied, a much greater repulsive force between the atoms arises shocking them into an incompressible insulating state.

Experiment Reveals Conductor-insulator Transition

back to top

Chemical heroes

The American Chemical Society announced its heroes of chemistry this month, highlighting chemical research used in dentistry, desalination, and medicine. "Heroes of Chemistry is a wonderful opportunity to recognize the people behind the products, medicines, and technology that are the foundations of modern society," said ACS President Thomas Lane. "It puts a human face on chemistry. These products don't just magically appear. Men and women like our 2009 Heroes invent them, develop them, and bring them to market." Among those cited for their industrial chemical prowess are William Mickols, and the late John Cadotte for their life-saving water filters and Sumita Mitra of 3M ESPE Dental Products Division in St. Paul, Minnesota.

'Heroes of Chemistry' for saving teeth, clean water, new high blood pressure drug

back to top

-- David Bradley, Science Journalist