Iron tetracarbonyl diiodide explained

Iron tetracarbonyl diiodide is the inorganic compound with the formula FeI₂(CO)₄. The molecule features four carbonyl ligands and two iodides. It is a low-spin complex of ferrous iron. As confirmed by X-ray crystallography, the compound has cis stereochemistry.^[1] It is a black solid that is soluble in dichloromethane and related organic solvents.

Preparation and reactions

It is prepared by the reaction of molecular iodine with iron pentacarbonyl, following a procedure first reported by Hieber and Wirschung in 1940:^[2]

Fe(CO)₅ + I₂ → FeI₂(CO)₄ + CO

Iron tetracarbonyl diiodide reacts with a variety of Lewis bases with displacement of one or two CO ligands.^[3]

References

1. Koordinatsionnaya Khimiya. 2008. 812–816. Yu. V. Torubayev, A. A. Pasynskii, P. Mathur. 34.
2. Über Metallcarbonyle. XXXII. Über Eisencarbonylhalogenide. W.. Hieber. A.. Wirsching. Z. Anorg. Allg. Chem.. 1940. 245. 35-58. 10.1002/zaac.19402450108.
3. 10.1021/ic9017882 . Synthesis and Mössbauer Characterization of Octahedral Iron(II) Carbonyl Complexes FeI₂(CO)₃L and FeI₂(CO)₂L₂: Developing Models of the [Fe]-H₂ase Active Site . Bin . Li . Tianbiao . Liu . Codrina V. . Popescu . Andrey . Bilko . Marcetta Y. . Darensbourg . Inorg. Chem. . 2009 . 48 . 23 . 11283–11289. 19860458 .