One of the most important sets of chemical reactions upon which all life depends is photosynthesis, the process by which green plants capture solar energy and store it in the form of chemical bonds that hold the atoms of a sugar molecule together. Photosynthesis is the Earth's dominant source of food, fuel and oxygen.
Scientists at Argonne National Laboratory near Chicago have created a synthetic molecule that mimics a key part of the photosynthetic process. They say they think the molecule will prove useful as a catalyst in industrial chemical processing, capturing the energy of light to speed chemical reactions that are otherwise slow.
Someday, said Michael Wasielewski, the molecule's inventor, improved versions may prove useful in a variety of chemical-making industries. One is the pharmaceutical industry, which wants to synthesize drug molecules that require difficult chemical reactions to bring them into existence.
The Argonne molecule is a combination of some of the same components in chlorophyll, the key substance in photosynthesis, and of an entirely synthetic component. When sunlight, or even light from a bulb, strikes the molecule, it causes electrons to jump from one atom to another in a predictable way.
Because electrons carry an electrical charge, they can act as a kind of glue holding atoms together. Electrons made available by the Argonne molecule can thus join the ingredient molecules of an industrial process, binding them into some new and useful substance.