Snatching carbon from the air.

• Position: YOUR LIFE

It is the reason why chemists envy green plants: by using photosynthesis, plants easily can fix the carbon dioxide that is so plentiful in air to make biomass, or organic compounds. Chemists also would like to be able to produce carbon compounds out of carbon dioxide from air. In contrast to the usual sources of carbon used today--fossil fuels and natural gas--carbon dioxide is a renewable resource and an environmentally friendly chemical reagent.

However, its carbon-oxygen bonds are too strong to be broken easily. Yet, researchers working with Yugen Zhang and Jackie Y. Ying at the Institute of Bioengineering and Nanotechnology in Singapore have developed a novel reason scheme by which C[O.sub.2] can be converted into methanol efficiently under very mild conditions. It is based on N-heterocyclic carbene catalyst and a silane as the reducing agent.

The basic framework of an N-heterocyclic carbene is a five-membered ring made of two nitrogen and three carbon atoms. Instead of having the usual four bonds, one of these carbon atoms only has two. The two electrons left over form a lone pair that makes this species highly reactive--reactive enough to attack C[O.sub.2].

The researchers...