Triiron dodecacarbonyl

Last updated
Triiron dodecacarbonyl
Fe3(CO)12lessFe-Fe.png
Names
IUPAC names
dodecarbonyltriiron,
tetra-μ-carbonyl-1:2κ4C,1:3κ2C,2:3κ2C-octacarbonyl-1κ3C,2κ3C,3κ2C-triangulo-triiron(3 FeFe)
Other names
Iron tetracarbonyl trimer
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.037.864 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 241-668-5
PubChem CID
  • InChI=1S/12CO.3Fe/c12*1-2;;;
    Key: HLYRMDDXFDINCB-UHFFFAOYSA-N
  • [C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[C-]#[O+].[Fe].[Fe].[Fe]
Properties
Fe3(CO)12
Molar mass 503.66 g/mol
Appearancedark black/green crystals
Melting point 165 °C (329 °F; 438 K)
Boiling point decomposes
insoluble
Structure
C2v
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-skull.svg GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg
Warning
H228, H302, H312, H331, H332, H371
Related compounds
Other cations
Triruthenium dodecacarbonyl
Triosmium dodecacarbonyl
Related iron carbonyls
Iron pentacarbonyl
Diiron nonacarbonyl
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Triiron dodecarbonyl is the organoiron compound with the formula Fe3(CO)12. It is a dark green solid that sublimes under vacuum. It is soluble in nonpolar organic solvents to give intensely green solutions. Most low-nuclearity clusters are pale yellow or orange. Hot solutions of Fe3(CO)12 decompose to an iron mirror, which can be pyrophoric in air.The solid decomposes slowly in air, and thus samples are typically stored cold under an inert atmosphere. [1] It is a more reactive source of iron(0) than iron pentacarbonyl.

Contents

Synthesis

It was one of the first metal carbonyl clusters synthesized. It was occasionally obtained from the thermolysis of Fe(CO)5:

3 Fe(CO)5 → Fe3(CO)12 + 3 CO

Traces of the compound are easily detected because of its characteristic deep green colour. UV-photolysis of Fe(CO)5 produces Fe2(CO)9, not Fe3(CO)12.

The usual synthesis of Fe3(CO)12 starts with the reaction of Fe(CO)5 with base: [2]

3 Fe(CO)5 + (C2H5)3N + H2O → [(C2H5)3NH][HFe3(CO)11] + 3 CO + CO2

followed by oxidation of the resulting hydrido cluster with acid:

[(C2H5)3NH][HFe3(CO)11] + HCl + CO → Fe3(CO)12 + H2 + [(C2H5)3NH]Cl

The original synthesis by Walter Hieber et al. entailed the oxidation of H2Fe(CO)4 with manganese dioxide. The cluster was originally formulated incorrectly as "Fe(CO)4". [3]

Structure

Saturated solution of Fe3(CO)12 in mesitylene. Fe3inC6Me3H3.jpg
Saturated solution of Fe3(CO)12 in mesitylene.

Elucidation of the structure of Fe3(CO)12 proved to be challenging because the CO ligands are disordered in the crystals. Early evidence for its distinctive C2v structure came from Mössbauer spectroscopic measurements that revealed two quadrupole doublets with similar isomer shifts but different (1.13 and 0.13 mm s−1) quadrupolar coupling constants.

Fe3(CO)12 consists of a triangle of iron atoms surrounded by 12 CO ligands. Ten of the CO ligands are terminal and two span an Fe---Fe edge, resulting in C2v point group symmetry. By contrast, Ru3(CO)12 and Os3(CO)12 adopt D3h-symmetric structures, wherein all 12 CO ligands are terminally bound to the metals. In solution Fe3(CO)12 is fluxional, resulting in equivalencing all 12 CO groups on the 13C NMR timescale. [4]

The anion [HFe3(CO)11] is structurally related to Fe3(CO)12, with the hydride replacing one bridging CO ligand. The bonding in the Fe-H-Fe subunit is described using concepts developed for diborane.

Reactions

Solutions of Fe3(CO)12 reacts with triphenylphosphine to give (triphenylphosphine)iron tetracarbonyl (and some bis(triphenylphosphine)iron tricarbonyl). [5]

Fe3(CO)12 + 3 P(C6H5)3 → 3 Fe(CO)4(P(C6H5)3)

Heating Fe3(CO)12 gives a low yield of the carbido cluster Fe5(CO)15C. Such reactions proceed via disproportionation of CO to give CO2 and carbon.

Fe3(CO)12 forms "ferroles" upon reaction with heterocycles such as thiophenes.

Fe3(CO)12 reacts with thiols and disulfides to give thiolate-bridged complexes, such as methylthioirontricarbonyl dimer: [6]

2 Fe3(CO)12 + 3 (CH3)2S2 → 3 [Fe(CO)3SCH3]2 + 6 CO. These complexes are studied as hydrogenase mimics. [7]

Safety

Fe3(CO)12 is hazardous as a source of carbon monoxide. Solid samples, especially when finely divided, and residues from reactions can be pyrophoric, which can ignite the organic solvents used for such reactions.

Related Research Articles

<span class="mw-page-title-main">Rhodium(III) chloride</span> Chemical compound

Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic solids featuring octahedral Rh(III) centres. Depending on the value of n, the material is either a dense brown solid or a soluble reddish salt. The soluble trihydrated (n = 3) salt is widely used to prepare compounds used in homogeneous catalysis, notably for the industrial production of acetic acid and hydroformylation.

<span class="mw-page-title-main">Iron pentacarbonyl</span> Chemical compound

Iron pentacarbonyl, also known as iron carbonyl, is the compound with formula Fe(CO)5. Under standard conditions Fe(CO)5 is a free-flowing, straw-colored liquid with a pungent odour. Older samples appear darker. This compound is a common precursor to diverse iron compounds, including many that are useful in small scale organic synthesis.

<span class="mw-page-title-main">Metal carbonyl</span> Coordination complexes of transition metals with carbon monoxide ligands

Metal carbonyls are coordination complexes of transition metals with carbon monoxide ligands. Metal carbonyls are useful in organic synthesis and as catalysts or catalyst precursors in homogeneous catalysis, such as hydroformylation and Reppe chemistry. In the Mond process, nickel tetracarbonyl is used to produce pure nickel. In organometallic chemistry, metal carbonyls serve as precursors for the preparation of other organometallic complexes.

Iron shows the characteristic chemical properties of the transition metals, namely the ability to form variable oxidation states differing by steps of one and a very large coordination and organometallic chemistry: indeed, it was the discovery of an iron compound, ferrocene, that revolutionalized the latter field in the 1950s. Iron is sometimes considered as a prototype for the entire block of transition metals, due to its abundance and the immense role it has played in the technological progress of humanity. Its 26 electrons are arranged in the configuration [Ar]3d64s2, of which the 3d and 4s electrons are relatively close in energy, and thus it can lose a variable number of electrons and there is no clear point where further ionization becomes unprofitable.

<span class="mw-page-title-main">Diiron nonacarbonyl</span> Chemical compound

Diiron nonacarbonyl is an organometallic compound with the formula Fe2(CO)9. This metal carbonyl is an important reagent in organometallic chemistry and of occasional use in organic synthesis. It is a more reactive source of Fe(0) than Fe(CO)5. This micaceous orange solid is virtually insoluble in all common solvents.

<span class="mw-page-title-main">Dicobalt octacarbonyl</span> Chemical compound

Dicobalt octacarbonyl is an organocobalt compound with composition Co2(CO)8. This metal carbonyl is used as a reagent and catalyst in organometallic chemistry and organic synthesis, and is central to much known organocobalt chemistry. It is the parent member of a family of hydroformylation catalysts. Each molecule consists of two cobalt atoms bound to eight carbon monoxide ligands, although multiple structural isomers are known. Some of the carbonyl ligands are labile.

<span class="mw-page-title-main">Triosmium dodecacarbonyl</span> Chemical compound

Triosmium dodecacarbonyl is a chemical compound with the formula Os3(CO)12. This yellow-colored metal carbonyl cluster is an important precursor to organo-osmium compounds. Many of the advances in cluster chemistry have arisen from studies on derivatives of Os3(CO)12 and its lighter analogue Ru3(CO)12.

<span class="mw-page-title-main">Triruthenium dodecacarbonyl</span> Chemical compound

Triruthenium dodecacarbonyl is the chemical compound with the formula Ru3(CO)12. Classified as metal carbonyl cluster, it is a dark orange-colored solid that is soluble in nonpolar organic solvents. The compound serves as a precursor to other organoruthenium compounds.

<span class="mw-page-title-main">Disodium tetracarbonylferrate</span> Chemical compound

Disodium tetracarbonylferrate is the organoiron compound with the formula Na2[Fe(CO)4]. It is always used as a solvate, e.g., with tetrahydrofuran or dimethoxyethane, which bind to the sodium cation. An oxygen-sensitive colourless solid, it is a reagent in organometallic and organic chemical research. The dioxane solvated sodium salt is known as Collman's reagent, in recognition of James P. Collman, an early popularizer of its use.

<span class="mw-page-title-main">Hexadecacarbonylhexarhodium</span> Chemical compound

Hexadecacarbonylhexarhodium is a metal carbonyl cluster with the formula Rh6(CO)16. It exists as purple-brown crystals that are slightly soluble in dichloromethane and chloroform. It is the principal binary carbonyl of rhodium.

Organoiron chemistry is the chemistry of iron compounds containing a carbon-to-iron chemical bond. Organoiron compounds are relevant in organic synthesis as reagents such as iron pentacarbonyl, diiron nonacarbonyl and disodium tetracarbonylferrate. While iron adopts oxidation states from Fe(−II) through to Fe(VII), Fe(IV) is the highest established oxidation state for organoiron species. Although iron is generally less active in many catalytic applications, it is less expensive and "greener" than other metals. Organoiron compounds feature a wide range of ligands that support the Fe-C bond; as with other organometals, these supporting ligands prominently include phosphines, carbon monoxide, and cyclopentadienyl, but hard ligands such as amines are employed as well.

<span class="mw-page-title-main">Iron tetracarbonyl dihydride</span> Chemical compound

Iron tetracarbonyl dihydride is the organometallic compound with the formula H2Fe(CO)4. This compound was the first transition metal hydride discovered. The complex is stable at low temperatures but decomposes rapidly at temperatures above –20 °C.

A metallacarboxylic acid is a metal complex with the ligand CO2H. These compounds are intermediates in reactions that involve carbon monoxide and carbon dioxide, these species are intermediates in the water gas shift reaction. Metallacarboxylic acids are also called hydroxycarbonyls.

<span class="mw-page-title-main">Cyclopentadienyliron dicarbonyl dimer</span> Chemical compound

Cyclopentadienyliron dicarbonyl dimer is an organometallic compound with the formula [(η5-C5H5)Fe(CO)2]2, often abbreviated to Cp2Fe2(CO)4, [CpFe(CO)2]2 or even Fp2, with the colloquial name "fip dimer". It is a dark reddish-purple crystalline solid, which is readily soluble in moderately polar organic solvents such as chloroform and pyridine, but less soluble in carbon tetrachloride and carbon disulfide. Cp2Fe2(CO)4 is insoluble in but stable toward water. Cp2Fe2(CO)4 is reasonably stable to storage under air and serves as a convenient starting material for accessing other Fp (CpFe(CO)2) derivatives (described below).

<span class="mw-page-title-main">Metal carbonyl hydride</span>

Metal carbonyl hydrides are complexes of transition metals with carbon monoxide and hydride as ligands. These complexes are useful in organic synthesis as catalysts in homogeneous catalysis, such as hydroformylation.

<span class="mw-page-title-main">Metal carbonyl cluster</span>

In chemistry, a metal carbonyl cluster is a compound that contains two or more metals linked in part by metal-metal bonds and containing carbon monoxide (CO) as the exclusive or predominant ligand. The area is a subfield of metal carbonyl chemistry, and many metal carbonyl clusters are in fact prepared from simple metal carbonyls. Simple examples include Fe2(CO)9, Fe3(CO)12, Mn2(CO)10. High nuclearity clusters include [Rh13(CO)24H3]2− and the stacked Pt3 triangules [Pt3n(CO)6n]2− (n = 2–6).

<span class="mw-page-title-main">Methylthioirontricarbonyl dimer</span> Chemical compound

Methylthioirontricarbonyl dimer, also known as methanethiolatoirontricarbonyl dimer, is an organometallic compound with the formula Fe2(SCH3)2(CO)6. It is a red volatile solid that is classified as a transition metal thiolate complex. It exists as air-stable red crystals with two isomers, where the methyl groups are either anti (isomer A) or syn (isomer B) with respect to each other.

<span class="mw-page-title-main">Ruthenium pentacarbonyl</span> Chemical compound

Ruthenium pentacarbonyl is the organoruthenium compound with the formula Ru(CO)5. It is a colorless, light-sensitive liquid that readily decarbonylates upon standing at room temperature. It is of academic interest as an intermediate for the synthesis of metal carbonyl complexes.

<span class="mw-page-title-main">Bis(triphenylphosphine)iron tricarbonyl</span> Chemical compound

Tricarbonylbis(triphenylphosphine)iron(0) is a coordination complex with the formula Fe(CO)3(PPh3)2 (Ph = C6H5). A yellow solid, this complex is derived from iron pentacarbonyl by replacement of two carbonyl ligands by triphenylphosphine (PPh3).

<span class="mw-page-title-main">(Triphenylphosphine)iron tetracarbonyl</span> Chemical compound

(Triphenylphosphine)iron tetracarbonyl is a coordination complex with the formula Fe(CO)4(PPh3) (Ph = C6H5). An off-white solid, this complex is derived from iron pentacarbonyl by replacement of one carbonyl ligand by triphenylphosphine (PPh3).

References

  1. Elschenbroich, C.; Salzer, A. ”Organometallics: A Concise Introduction” (2nd Ed) (1992) from Wiley-VCH: Weinheim. ISBN   3-527-28165-7
  2. McFarlane, W.; Wilkinson, G. W. (1966). "Triiron dodecacarbonyl". Inorganic Syntheses . 8: 181–3. doi:10.1002/9780470132395.ch47. ISBN   9780470132395.
  3. Hieber, W.; Leutert, F. (1932). "Über Metallcarbonyle. XII. Die Basenreaktion des Eisenpentacarbonyls und die Bildung des Eisencarbonylwasserstoffs (Metal carbonyls. XII. The Reaction of Iron Pentacarbonyl with Bases and the Formation of Iron Hydrocarbonyl)". Zeitschrift für anorganische und allgemeine Chemie. 204: 145–64. doi:10.1002/zaac.19322040115.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. Farrugia, Louis J. (1997). "Dynamics and Fluxionality in Metal Carbonyl Clusters: Some Old and New Problems". Journal of the Chemical Society, Dalton Transactions (11): 1783–1792. doi:10.1039/A608514H.
  5. Clifford, A. F.; Mukherjee, A. K. (1966). "Iron Carbonyl Complexes of Triphenylphosphine, Triphenylarsine, and Triphenylstibine". Inorganic Syntheses. Inorganic Syntheses. Vol. VIII. pp. 185–191. doi:10.1002/9780470132395.ch49. ISBN   9780470132395.
  6. King, R. B. "Organosulfur Derivatives of Metal Carbonyls. I. The Isolation of Two Isomeric Products in the Reaction of Triiron Dodecacarbonyl with Dimethyl Disulfide" J. Am. Chem. Soc. 1962, vol. 84, 2460. doi : 10.1021/ja00871a045
  7. Synthesis, Purification, and Characterization of a µ-(1,3-Propanedithiolato)-hexacarbonyldiiron Laboratory Experiment or Mini-Project for Inorganic Chemistry or Integrated Laboratory Carmen F. Works 836 Journal of Chemical Education Vol. 84 No. 5 May 2007 Abstract