Editing Cyclopentadienyl complex (section)

===Bulky Cp ligands===
{{main|Bulky cyclopentadienyl ligands}}
[[Pentamethylcyclopentadiene]] gives rise to pentamethylcyclopentadienyl (Cp*) complexes.  These ligands are more basic and more lipophilic.  Replacing methyl groups with larger substituents results in cyclopentadienes that are so encumbered that pentaalkyl derivatives are no longer possible. Well-studied ligands of this type include C<sub>5</sub>R<sub>4</sub>H<sup>−</sup> (R = iso-Pr) and 1,2,4-C<sub>5</sub>R<sub>3</sub>H<sub>2</sub><sup>−</sup> (R = ''tert''-Bu).