Carbon can exceed four-bond limit
Chemists confirm links to six other atoms in unusual molecule
BONDING TIME When hexamethylbenzene loses two electrons, it rearranges from a flat hexagonal ring into the five-sided pyramid shown here. The carbon atom on top of the pyramid bonds to six other carbon atoms as opposed to the usual four.
E. Otwell
A molecule originally proposed more than 40 years ago breaks the rules about how carbon connects to other atoms, scientists have confirmed.