Cyclopentadienyl anion

From Wikipedia, the free encyclopedia
  (Redirected from Cyclopentadienide)
Jump to: navigation, search

In organic chemistry, the cyclopentadienyl anion or cyclopentadienide is an aromatic species with a formula of [C5H5]-.[1] Its name derives from the molecule cyclopentadiene. Salts of the cyclopentadienyl anion can be stable, e.g., Sodium cyclopentadienide. more complex coordination compounds are known as cyclopentadienyl complexes, such as metallocene

It is a Pentagonal, planar, cyclic ion; as well, it has 6 π-electrons (4n+2, where n=1), which fulfills Hückel's rule of aromaticity. It can coordinate as a ligand to metal atoms.

The structure shown is a composite of five resonance contributors in which each carbon carries part of the negative charge.

See also[edit]


  1. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version:  (2006–) "molecule".