Nature Chem. doi:10.1038/nchem.248 (2009)

Rare compounds in which carbon — the archetypal organic element — seems to behave like a metal may be more widespread than previously thought.

In typical organic compounds, a carbon atom forms four covalent bonds by sharing its four most accessible electrons. But Alois Fürstner and his colleagues at Germany's Max Planck Institute for Coal Research in Mülheim an der Ruhr argue that in some newly synthesized and previously known compounds, carbon's bonding behaviour is best described as donating pairs of electrons to, or accepting pairs of electrons from, neighbouring atoms — behaviour seen in positively charged metal ions.

This peculiar situation, which blurs the traditional divide between organic and inorganic chemistry, could form the basis of new types of catalyst.