Editing Metallocene (section)

===Polynuclear and heterobimetallic metallocenes===
*Ferrocene derivatives: biferrocenophanes have been studied for their mixed [[valence (chemistry)|valence]] properties. Upon one-electron oxidation of a compound with two or more equivalent ferrocene moieties, the electron vacancy could be localized on one ferrocene unit or completely [[delocalized]].
*[[Ruthenocene]] derivatives: in the solid state biruthenocene is disordered and adopts the transoid conformation with the mutual orientation of Cp rings depending on the intermolecular interactions.
*[[Vanadocene]] and [[rhodocene]] derivatives: vanadocene complexes have been used as starting materials for the synthesis of heterobimetallic complexes. The 18 [[valence electron]] ions [Cp<sub>2</sub>Rh]<sup>+</sup> are very stable, unlike the neutral monomers Cp<sub>2</sub>Rh which [[dimer (chemistry)|dimerize]] immediately at room temperature and they have been observed in [[matrix isolation]].