The moment your grade-school teacher or your favorite TV show (Magic School Bus) mentioned the existence of atoms, you would be shown an image of electrons orbiting a nucleus like planets around a solar system. You were hopelessly in love with such a beautiful thing… The symmetry alone was just gorgeous! Oh, what you would have given to see it in real life. But soon, your heart would be broken the moment you were taught that such a model was wrong. No orbiting electrons! Just a cloud of the stuff! They just exist. Bonds? They exist only in equations and theories… Not in pictures!
OR DO THEY?
That’s right, barely a week ago, on September 13th, pictures of a small molecule (pentacene) were released. These weren’t ordinary pictures though: they were so detailed that even the type of atomic bonds between the atoms were visible. For this, we have to thank an IBM team based in Zurich. The team used a slightly different form of atomic force microscopy (AFM) to obtain these images. Regular AFM uses a metal tip to pass over the desired object multiple times, very much like a record needle. The team put a slight spin on this method in that they used the metal tip to pick up a molecule of carbon monoxide, and used that as the tip instead.
The experiments were so delicate that the images show how long the atomic bonds are, and the density of the electrons (a brighter image means less density). All of this shows us what types of bonds are present and how many pairs of electrons the atoms share. Instruments had to be kept constantly cooled at a temperature near absolute zero. Additionally, any vibrations coming from the surroundings would have jeopardized the experiments, thus the AFM had to be carried out in an isolated environment on chemically within the molecules.
This was used to study graphene (single atom-thick sheets of pure carbon) under a new lens. Graphene holds a lot of promise as it has many applications in electronics and research, and with this new imaging technology we now have a higher degree of detail in studying small molecules, such as the aforementioned pentacene. The world (of possibilities) just got a little larger!
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