Chemical bonds can form or break incredibly quickly. In the past decade or so, scientists have visualized such ultrafast reactions with laser pulses briefer than a trillionth of a second (SN: 11/13/99, p. 310).
That technique has worked in gases or liquids, but not on surfaces. Now a team of physicists reports real-time viewing of a reaction of molecules on a surface. These reactions lie at the heart of important technologies such as catalytic converters.
The problem with surfaces is that they contain a sea of energy-hungry electrons that can cut short a chemical reaction. A reaction can get started when a laser pulse excites an electron so that it moves into a molecule adhered to the surface. However, the electron's energy usually dissipates among other surface electrons before such a reaction can run its course.