Sunday, September 16, 2012

Microscope shows atom bonds in molecules

Microscopes allow us to see small things that cannot be observed with the eye. Examples include tissue structure, cells, or even individual parts of cells. But as technology progresses, we gain the ability to image increasingly smaller things. Now, researchers have found a way to reveal the bonds between individual atoms in a molecular structure. Basically, it shows us the most fundamental structure of matter, even though atoms themselves are also built up from individual parts. This technology ought to help with studying compounds and their chemical properties.

Originally, the technique that was used by the scientists was developed by IBM. The company already showed the first picture of an individual molecule, which is a pretty impressive feat. In order to make pictures of such small things, one cannot use ordinary microscopy. A technique called atomic force microscopy was developed in order to make images of things at the atomic level, and it works with a tiny needle that is 'loaded' with a carbon monoxide molecule. While the needle moves across the surface of a molecule that ought to be imaged, the electrons in both molecules repulse each other.

By performing electromagnetic measurements, computers can derive images from the degree of repulsion. It is however necessary to maintain a temperature of about -268 degrees, because higher temperatures will cause vibrations that result in blurry pictures. When the scientists performed measurements and constructed the corresponding images, the results were as found below: the picture clearly shows the individual connections between atoms in the molecular structure.
Chemistry works on the level of atomic bonds: when bonds, kept together by electrons, break, atoms can make new connections. By imaging the individual connections and looking at what happens during chemical reactions, molecular imaging can help us gain more knowledge about the behaviour of compounds. The scientists want to use the microscope to study graphene, which consists of several carbon layers and is of interest for use in electronics. 

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