Biferrocene is the

organometallic compound Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and ...

with the formula C₅H₅)Fe(C₅H₄)sub>2. It is the product of the formal dehydrocoupling of

ferrocene Ferrocene is an organometallic chemistry, organometallic compound with the formula . The molecule is a Cyclopentadienyl complex, complex consisting of two Cyclopentadienyl anion, cyclopentadienyl rings sandwiching a central iron atom. It is an o ...

, analogous the relationship between biphenyl and benzene. It is an orange, air-stable solid that is soluble in nonpolar organic solvents. Biferrocene can be prepared by the

Ullmann coupling The Ullmann reaction or Ullmann coupling, named after Fritz Ullmann, couples two aryl or alkyl groups with the help of copper. The reaction was first reported by Ullmann and his student Bielecki in 1901. It has been later shown that palladium and ...

of iodoferrocene. Its one-electron oxidized derivative C₅H₅)Fe(C₅H₄)sub>2⁺ attracted attention as a prototypical

mixed-valence Mixed valence complexes contain an element which is present in more than one oxidation state. Well-known mixed valence compounds include the Creutz–Taube complex, Prussian blue, and molybdenum blue. Many solids are mixed-valency including ...

compound. A related compound is biferrocenylene, e(C₅H₄)₂sub>2 wherein all

cyclopentadienyl Cyclopentadienyl can refer to * Cyclopentadienyl anion, or cyclopentadienide, ** Cyclopentadienyl ligand * Cyclopentadienyl radical, • * Cyclopentadienyl cation, See also * Pentadienyl {{Chemistry index ...

rings are coupled into two

fulvalene Fulvalene (bicyclopentadienylidene) is the member of the fulvalene family with the molecular formula C10H8. It is of theoretical interest as one of the simplest non-benzenoid conjugated hydrocarbons. Fulvalene is an unstable isomer of the mor ...

ligands.

Reactions

Biferrocene can easily be converted into a

mixed-valence complex Mixed valence complexes contain an element which is present in more than one oxidation state. Well-known mixed valence compounds include the Creutz–Taube complex, Prussian blue, and molybdenum blue. Many solids are mixed-valency including ...

, which is called biferrocenium. This e(II)-Fe(III)cation is a class II type (0.707 > α > 0) mixed-valence complex according to the Robin-Day classification.

Derivatives

Aminophosphine In organophosphorus chemistry, aminophosphines are compounds with the formula R3−nP(NR2)n where R is a hydrogen or organic substituent, and n = 0, 1, or 2. At one extreme, the parents H2PNH2 and are lightly studied and fragile. At the other extre ...

ligands with biferroceno substituents have been prepared as catalysts for asymmetric

allylic substitution An allylic rearrangement or allylic shift is an organic chemical reaction in which reaction at a center vicinal to a double bond causes the double bond to shift to an adjacent pair of atoms: It is encountered in both nucleophilic and electrophi ...

and

asymmetric hydrogenation Asymmetric hydrogenation is a chemical reaction that adds two atoms of hydrogen to a target (substrate) molecule with three-dimensional spatial selectivity. Critically, this selectivity does not come from the target molecule itself, but from oth ...

of alkenes.

Related compounds

* Bis(fulvalene)diiron

References

{{Cyclopentadienide complexes Ferrocenes Sandwich compounds Cyclopentadienyl complexes