Decamethylferrocene

Decamethylferrocene

Names
IUPAC name Bis(η5 pentamethylcyclopentadienyl)iron(II)
Other names Decamethyl-ferrocene; 1,1',2,2',3,3',4,4',5,5'-Decamethyl-ferrocene; Bis(pentamethylcyclopentadienyl)iron(II); Permethylferrocene
Identifiers
CAS Number	12126-50-0 Y
3D model (JSmol)	Interactive image
ChemSpider	4321548 N
ECHA InfoCard	100.116.086
PubChem CID	5148079
InChI InChI=1S/2C10H15.Fe/c2*1-6-7(2)9(4)10(5)8(6)3;/h2*1-5H3;/q2*-1;+2 N Key: SEYZDJPFVVXSRB-UHFFFAOYSA-N N InChI=1/2C10H15.Fe/c2*1-6-7(2)9(4)10(5)8(6)3;/h2*1-5H3;/q2*-1;+2 Key: SEYZDJPFVVXSRB-UHFFFAOYAP
SMILES C[c-]1c(c(c(c1C)C)C)C.C[c-]1c(c(c(c1C)C)C)C.[Fe+2]
Properties
Chemical formula	C20H30Fe
Molar mass	326.31 g·mol−1
Appearance	Yellow crystalline solid
Melting point	291 to 295 °C (556 to 563 °F; 564 to 568 K)
Sublimation conditions	413 K, 5.3 Pa
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Decamethylferrocene is a sandwich compound. In terms of structure and bonding it resembles ferrocene, but with a methyl group on each of the carbons of the Cp rings. It is a yellow crystalline solid that is a weak reductant.

Decamethylferrocene is prepared in the same manner as ferrocene from pentamethylcyclopentadiene. This method can be used to produce other decamethylcyclopentadienyl sandwich compounds.

The product can be purified by sublimation. FeCp₂* has staggered Cp* rings. The average distance between iron and each carbon is approximately 2.050 Å. This structure has been confirmed by X-ray crystallography.

Like ferrocene, decamethylferrocene forms a stable cation because Fe(II) is easily oxidized to Fe(III). Because of the electron donating methyl groups on the Cp* groups, decamethylferrocene is more reducing than is ferrocene. In a solution of MeCN the reduction potential for the [FeCp₂*]^+/0 couple is -0.48 V compared to a [FeCp₂]^0/+ reference (-0.59 V V vs Fc/Fc+ in CH₂Cl₂). Oxygen is reduced to hydrogen peroxide by decamethylferrocene in acidic solution.

Using powerful oxidants (e.g. SbF₅ or AsF₅ in SO₂, or XeF⁺ Sb₂F₁₁⁻ in HF/SbF₅) decamethylferrocene is oxidized to a stable dication. In the Sb₂F₁₁⁻ salt, the Cp* rings are parallel. In contrast, a tilt angle of 17° between the Cp* rings is observed in the crystal structure of the SbF₆⁻ salt.