First images of molecules in reaction
Amazing pictures show atomic bonds look just like the textbook diagrams. James Mitchell Crow reports.
What does a molecule look like? It turns out, exactly like the drawings we made in high school chemistry class. A striking new set of images confirms that chemists’ cartoons, worked out with mathematics and a pencil long before there were computers, really do represent the real thing.
The tiny arrangements of atoms, held in place by chemical bonds, are far too small for conventional microscopes to see. In the past, chemists devised ingenious indirect methods for measuring them and cartoon-style shorthand diagrams to describe what they had measured. But now the new pictures show they got it absolutely spot-on.
The images, which show actual molecules, in atomic-scale detail, were taken using a processvcalled non-contact atomic force microscopy (nc-AFM), which moves a single-atom-sharp “finger” backwards and forwards across the molecule, line by line. It is like reading Braille, explains Felix Fischer, who co-led the work at the University of California, Berkeley.
The images show a molecule before and after a chemical reaction, capturing the way that the bonds between atoms are shuffled when the substance is heated. Fischer is researching ways to improve industrial catalysts.