Watching Simple Molecules React at Surfaces, A-Molecule-At-A-Time

Scanning Tunneling Microscopy allows one to characterize the geometry of molecules at surfaces (their positioning, alignment and tilt) before and after they react.

The motions of the atoms and radicals as they react can therefore be visualized in the form of movies, using a blend of quantum mechanics and classical mechanics to obtain the intermediate configurations. The atomic and molecular motions in reactions at semi- conductor and metal surfaces, obtained in this fashion, will be exemplified.

Fortunately simple principles can be deduced governing the process of reaction, so that this visualization is more rewarding than would be the reconstruction of the script of Hamlet from its first and last acts. In fact, thanks to STM and the power of modern computing, our understanding of reaction dynamics at the nano-level is currently undergoing a renaissance.