Chemistry

Researchers from the National Institute of Standards and Technology (NIST) and Seoul National University (SNU) have learned how to tweak a new class of polymer-based semiconductors to better control the location and alignment of the components of the blend.

Their recent results—how to move the top to the bottom—could enable the design of practical, large-scale manufacturing techniques for a wide range of printable, flexible electronic displays and other devices.

Organic semiconductors—novel carbon-based molecules that have similar electrical properties to more conventional semiconducting materials like silicon and germanium—are a hot research topic because practical, high-performance organic semiconductors would open up whole new categories of futuristic electronic devices. Think of tabloid-sized “digital paper” that you could fold up into your pocket or huge sheets of photovoltaic cells that are dirt cheap because they’re manufactured by—basically—ink-jet printing.


LLNL researchers care about the environment too. To keep Mother Nature safe while we blow stuff up, they have added unique green solvents (ionic liquids) to an explosive called TATB (1,3,5-triamino-2,4,6-trinitrobenzene) and improved the crystal quality and chemical purity of the material.

Most explosives belong to a general class of materials called molecular crystals, which have become important building blocks in a number of other applications ranging from drugs, pigments, agrochemicals, dyes and optoelectronics. Many of these materials, including TATB, are bound together by a strong network of hydrogen-bonds. This extended network often makes these materials nearly insoluble in common organic solvents, leading to poor quality and limited size crystals, which in turn hinders progress in many technological applications.

The semiconductor silicon and the ferromagnet iron are the basis for much of mankind's technology, used in everything from computers to electric motors.

Writing in Nature, an international group of scientists from the UK, USA and Lesotho report that they have combined these elements with a small amount of another common metal, manganese, to create a new material which is neither a magnet nor an ordinary semiconductor.

They then show how a small magnetic field can be used to switch ordinary semiconducting behavior (such as that seen in the electronic-grade silicon which is used to make transistors) back on.


A $2500 bottle of Château Latour wine that scored a 98 on the Wine Spectator point scale is not for amateurs. The sobering business of the high end wine trade involves scientists on a variety of different levels. One big problem is that wine—especially superb wine—goes bad. A chemist at U.C. Davis has found a way to tell if a bottle is fit for the Queen of England, or for the Queen of Wishful Thinking.

In the basement of the chemistry building at U.C. Davis, associate professor Matthew Augustine works with a unique nuclear magnetic resonance device of which there are only two in the U.S. Besides being able to do things like locating liquid explosives in sealed containers such as turpentine and nitro glycerin, Augustine has used the NMR to test the quality of wine.


Tetra-Amido Macrocyclic Ligands (TAMLs) are environmentally friendly catalysts with a host of applications for reducing and cleaning up pollutants, and a prime example of "green chemistry."

Carnegie Mellon University's Terry Collins, the catalyst's inventor, believes that the small-molecule catalysts have the potential to be even more effective than previously proven. Collins will discuss how iron-TAMLs (Fe-TAMLs) work and areas for further research, citing evidence from mechanistic and kinetic studies of the catalyst on Monday, Aug. 18 at the 236th national meeting of the American Chemical Society in Philadelphia.

In chemistry, just as in life, threesomes do not break up neatly.

Open-minded thinkers may disagree and say that theoretically clean three-way splits can happen, but no one had actually witnessed one – until now.

A paper in the Aug. 8 issue of Science provides the first hard evidence for the simultaneous break-up of a molecule into three equal parts, called "concerted break-ups."

Maxine Clarke highlights a bit of recent controversy regarding Open Notebook Science that has been bouncing around the blogosphere and FriendFeedosphere. There are some who interpret the ongoing publication of our laboratory notebook as an expectation for the world to read it like a magazine. For someone who is not a collaborator or working in a related area that would make about as much sense as reading the phone book. Here is an example of how an Open Notebook should be used:
Terrace-like elevations of just a few nanometres can form during production of organic thin films made from electrically conductive material. This phenomenon was previously only known from inorganic materials and is crucially important for future production of a new generation of semi-conductor components based on organic thin films.

Inorganic semi-conductors have a simple construction and have made high-performance computers possible. In contrast, organic semi-conductors are complex but enable production of innovative electronic circuits, as vividly demonstrated by the first prototypes for roll-up screens. Yet these benefits of organic semi-conductors can only be fully harnessed when the response of their organic molecular layer - whose thinness is crucial in functional terms - is better understood.

The national research network (NRN) "Interface controlled and functionalised organic thin films" of the Austrian Science Fund FWF is contributing to precisely this understanding.

This material originates from volcanoes but in synthesized form it takes up around a third of the average packet of washing powder and it also helps refine 99 per cent of the world's petrol (*) - when it's not used to clean up nuclear waste.

You've probably never heard of it but this extremely useful material is a zeolite. A European team of scientists has revealed, for the first time, its chemical structure using the European Synchrotron Radiation Facility (ESRF). This research opens door to more effective zeolites in the future.

Zeolites are crystalline white minerals, mostly made of aluminium, silicon and oxygen. Their structure is like molecular scaffolding, and thanks to this structure they are frequently used as a “molecular sieve.” This means that with their pores they can separate different molecules and cause different reactions, which are crucial in treating petrol and producing chemicals. Zeolites can also provoke ion exchange, which is useful in water softening or in the removal of nuclear waste (by filtering the radioactive components).


Glass has always been a chemical and physical puzzle. Unlike most solids, glass is actually more like a slow-moving liquid - a 'jammed' state of matter that moves very slowly. Like cars in traffic, atoms in a glass can't reach their destination because the route is blocked by their neighbors, so it never really becomes a solid.

For more than 50 years most scientists have tried to figure out the glass puzzle. Work so far has concentrated on trying to understand the traffic jam, but now Dr Paddy Royall from the University of Bristol, with colleagues in Canberra and Tokyo, has shown that the problem really lies with the destination, not with the traffic jam.

Publishing in Nature Materials, the team has revealed that glass 'fails' to be a solid due to the special atomic structures that form in a glass when it cools (ie, when the atoms arrive at their destination).