Cyclopentadienyliron dicarbonyl iodide

Cyclopentadienyliron dicarbonyl iodide

Identifiers
CAS Number	12078-28-3 Y
3D model (JSmol)	Interactive image
ChemSpider	35466814
ECHA InfoCard	100.155.006
EC Number	626-622-8
PubChem CID	138114916
InChI InChI=1S/C5H5.2CO.Fe.HI/c1-2-4-5-3-1;2*1-2;;/h1-5H;;;;1H/p-1 Key: XPSYTVVYYIGNSG-UHFFFAOYSA-M
SMILES [C-]#[O+].[C-]#[O+].C1=C[CH]C=C1.[Fe].[I-]
Properties
Chemical formula	C7H5FeIO2
Molar mass	303.864 g·mol−1
Appearance	Black crystalline solid (density = 2.374 g/cm3)
Melting point	119 °C (246 °F; 392 K)
Structure
Space group	Cs
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H312, H332
Safety data sheet (SDS)	Here
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Cyclopentadienyliron dicarbonyl iodide is an organoiron compound with the formula (C₅H₅)Fe(CO)₂I. It is a dark brown solid that is soluble in common organic solvents. (C₅H₅)Fe(CO)₂I, or FpI as it is often known, is an intermediate for the preparation of other organoiron compounds such as in ferraboranes.

Cyclopentadienyliron dicarbonyl iodide is synthesized by the reaction of cyclopentadienyliron dicarbonyl dimer with I₂:^[1]

Cp₂Fe₂(CO)₄ + I₂ → 2 CpFe(CO)₂I

It was first reported by Pauson and Hallam.^[2]

The compound has C_s symmetry, with a mirror plane intersecting one carbon of the Cp ring as well as the iron and iodide centre. The compound adopts a piano stool structure: the cyclopentadienyl ligand is the "seat" and three other ligands are "legs". Such compounds are members of the half-sandwich family of compounds, which is a subgroup of the metallocenes. X-ray crystallography shows the following features: Fe-Cp centroid = 1.72, Fe-I = 2.61, and Fe-CO = 1.78 Å.^[3]

Electron counting of this iron(II) complex indicates that (C₅H₅)Fe(CO)₂I is an 18-electron complex: using the neutral method there are 8 electrons from the iron, 5 electrons from the cyclopentadienyl anion, 2 electrons from each of the carbonyls, and 1 electron from the iodide.