Seeing the Invisible

People have always yearned to peer at that which can’t be seen. Hence, telescopes to see into the distance and microscopes to magnify the tiny.

The resolving power for any such instrument depends of the wavelength of light used for detection and the ingenuity of the optical device used to capture that light. The human eye, as an example, is highly ingenious but limited to the visible wavelengths, thus restricting our ability to directly inspect small objects.

Electron microscopes use smaller wavelengths and can thus see smaller objects. But nobody thought we could ever see the individual atoms and bonds of a molecule because the necessary light would be so energetic as to destroy the very molecule under observation.

Luckily, intractable problems attract smart scientists. A group from IBM Research in Zurich and the Debye Institute in the Netherlands avoided the optical problem by touching the molecule instead of looking at it (Science 325: 5944 [28 August 2009], 1110–1114).

The new work uses atomic-force microscopy to visualize the complete chemical structure of pentacene, a five-ring aromatic hydrocarbon. The trick in this accomplishment lies in refining the tip of the AFM device (in this case with adsorbed carbon monoxide) so that it doesn’t perturb the sample and allows highly precise visualization. The technical achievement is dramatic enough, but the experience of actually “seeing” a real molecule is truly cosmic.

Check it out yourself, and be prepared for the most remarkable reality show possible. The wholly authentic images will send a chill down your spine.

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Periodic Tabloid is an ongoing record of the activities of the Chemical Heritage Foundation’s staff and scholars, whose work tells the story of chemistry over the centuries up to modern times. Stay tuned for behind-the-scenes coverage of our events, exclusive supplemental materials to our publications, analysis of pressing contemporary scientific issues, and much more.