Sesquifulvalene or pentaheptafulvalene is a hydrocarbon in the fulvalenes with chemical formula C12H10. It is composed of linked cyclopentadiene and cycloheptatriene rings.
Properties
In the
ground state, which is a
singlet state, the central
double bond is
dielectric, with a partial positive charge on the carbon atom of heptagonal ring and a partial negative charge on the carbon atom of pentagonal ring. This shift makes each ring have closer to 4
n+2
pi electron, in keeping with the Hückel's pattern of
aromaticity. However, in the lowest
quintet state, the central double bond is
polar bond with a partial negative charge on the carbon atom of heptagonal ring and a partial positive charge on the carbon atom of pentagonal ring due to Baird's rule.
See also
