Diiron nonacarbonyl

Last updated
Diiron nonacarbonyl
Diiron nonacarbonyl Fe2(CO)9noFeFe.png
Diiron nonacarbonyl
Diiron nonacarbonyl Diiron-nonacarbonyl-from-xtal-1974-3D-balls.png
Diiron nonacarbonyl
Fe2(CO)9closeUp.png
Names
IUPAC name
Diiron nonacarbonyl, tri-μ-carbonyl-bis(tricarbonyliron)(Fe—Fe)
Other names
Iron enneacarbonyl
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.035.765 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 239-359-5
PubChem CID
  • InChI=1S/9CO.2Fe/c9*1-2;; Yes check.svgY
    Key: JCXLZXJCZPKTBW-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/9CO.2Fe/c9*1-2;;
    Key: JCXLZXJCZPKTBW-UHFFFAOYAN
  • O=C1[Fe]2(=C=O)(=C=O)(=C=O)C(=O)[Fe]1(=C=O)(=C=O)(=C=O)C2=O
Properties
Fe2C9O9
Molar mass 363.78 g/mol
Appearanceorange crystals
Density 2.08 g/cm3
Melting point decomposes at 100 °C [1]
insoluble, does not react with water [2]
Structure
0 D
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Toxic, flammable
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-pollu.svg GHS-pictogram-skull.svg
Danger
Related compounds
Related iron carbonyls
Iron pentacarbonyl
Triiron dodecacarbonyl
Related compounds
Dimanganese decacarbonyl
Dicobalt octacarbonyl
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

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. [3] It is a more reactive source of Fe(0) than Fe(CO)5. This micaceous orange solid is virtually insoluble in all common solvents.

Contents

Synthesis and structure

Following the original method, [4] photolysis of an acetic acid solution of Fe(CO)5 produces Fe2(CO)9 in good yield: [5] [6]

2 Fe(CO)5 → Fe2(CO)9 + CO

Fe2(CO)9 consists of a pair of Fe(CO)3 centers linked by three bridging CO ligands. Although older textbooks show an Fe-Fe bond consistent with the 18 electron rule (8 valence electrons from Fe, two each from the terminal carbonyls, one each from the bridging carbonyls and one from the other Fe atom in the metal-metal bond), theoretical analyses have consistently indicated the absence of a direct Fe-Fe bond: [7] this latter model proposes an Fe-C-Fe three-center-two-electron "banana bond" for one of the bridging carbonyls. The minor isomer has been crystallized together with C60. The iron atoms are equivalent and octahedral molecular geometry. Elucidation of the structure of Fe2(CO)9 proved to be challenging because its low solubility inhibits growth of crystals. The Mößbauer spectrum reveals one quadrupole doublet, consistent with the D3h-symmetric structure.

Reactions

Fe2(CO)9 is a precursor to compounds of the type Fe(CO)4L and Fe(CO)3(diene). Such syntheses are typically conducted as THF slurries. In these conversions, it is proposed that small amounts of Fe2(CO)9 dissolve according to the following reaction: [8]

Fe2(CO)9 → Fe(CO)5 + Fe(CO)4(THF)

Oxidative addition of allyl bromide to diiron nonacarbonyl gives the allyl iron(II) derivaive: [9]

Fe2(CO)9 + BrCH2CH=CH2 → FeBr(CO)3(C3H5) + CO + Fe(CO)5

Cyclobutadieneiron tricarbonyl is prepared similarly using 3,4-dichlorocyclobutene: [10]

C4H4Cl2 + 2 Fe2(CO)9 → (C4H4)Fe(CO)3 + 2 Fe(CO)5 + 2 CO + 2 FeCl2.

Fe2(CO)9 has also been employed in the synthesis of cyclopentadienones via a net [2+3]-cycloaddition from dibromoketones, known as the Noyori [3+2] reaction. [11]

(Benzylideneacetone)iron tricarbonyl, with the formula (C6H5CH=CHC(O)CH3)Fe(CO)3 is prepared by the reaction of diiron nonacarbonyl with benzylideneacetone. [12] This complex is a source of the Fe(CO)3 fragment.

Low temperature UV/vis photolysis of Fe2(CO)9 yields the Fe2(CO)8 unsaturated complex, producing both CO-bridged and unbridged isomers. [13]

Safety

Metal carbonyls are typically treated as if they are highly toxic. [5]

Related Research Articles

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

Molybdenum hexacarbonyl (also called molybdenum carbonyl) is the chemical compound with the formula Mo(CO)6. This colorless solid, like its chromium, tungsten, and seaborgium analogues, is noteworthy as a volatile, air-stable derivative of a metal in its zero oxidation state.

<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.

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

Cyclobutadieneiron tricarbonyl is an organoiron compound with the formula Fe(C4H4)(CO)3. It is a yellow oil that is soluble in organic solvents. It has been used in organic chemistry as a precursor for cyclobutadiene, which is an elusive species in the free state.

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

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. It is a more reactive source of iron(0) than iron pentacarbonyl.

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

Tungsten hexacarbonyl (also called tungsten carbonyl) is an organometallic compound with the formula W(CO)6. This complex gave rise to the first example of a dihydrogen complex.

<span class="mw-page-title-main">Metal nitrosyl complex</span> Complex of a transition metal bonded to nitric oxide: Me–NO

Metal nitrosyl complexes are complexes that contain nitric oxide, NO, bonded to a transition metal. Many kinds of nitrosyl complexes are known, which vary both in structure and coligand.

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

(Benzylideneacetone)iron tricarbonyl is the organoiron compound with the formula (C6H5CH=CHC(O)CH3)Fe(CO)3. It is a reagent for transferring the Fe(CO)3 unit. This red-colored compound is commonly abbreviated (bda)Fe(CO)3.

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

Cyclopentadienylmolybdenum tricarbonyl dimer is the chemical compound with the formula Cp2Mo2(CO)6, where Cp is C5H5. A dark red solid, it has been the subject of much research although it has no practical uses.

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. 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.

Transition metal carbyne complexes are organometallic compounds with a triple bond between carbon and the transition metal. This triple bond consists of a σ-bond and two π-bonds. The HOMO of the carbyne ligand interacts with the LUMO of the metal to create the σ-bond. The two π-bonds are formed when the two HOMO orbitals of the metal back-donate to the LUMO of the carbyne. They are also called metal alkylidynes—the carbon is a carbyne ligand. Such compounds are useful in organic synthesis of alkynes and nitriles. They have been the focus on much fundamental research.

<span class="mw-page-title-main">Half sandwich compound</span> Class of coordination compounds

Half sandwich compounds, also known as piano stool complexes, are organometallic complexes that feature a cyclic polyhapto ligand bound to an MLn center, where L is a unidentate ligand. Thousands of such complexes are known. Well-known examples include cyclobutadieneiron tricarbonyl and (C5H5)TiCl3. Commercially useful examples include (C5H5)Co(CO)2, which is used in the synthesis of substituted pyridines, and methylcyclopentadienyl manganese tricarbonyl, an antiknock agent in petrol.

<span class="mw-page-title-main">Transition-metal allyl complex</span>

Transition-metal allyl complexes are coordination complexes with allyl and its derivatives as ligands. Allyl is the radical with the connectivity CH2CHCH2, although as a ligand it is usually viewed as an allyl anion CH2=CH−CH2, which is usually described as two equivalent resonance structures.

<span class="mw-page-title-main">Transition metal isocyanide complexes</span> Class of chemical compounds

Transition metal isocyanide complexes are coordination compounds containing isocyanide ligands. Because isocyanides are relatively basic, but also good pi-acceptors, a wide range of complexes are known. Some isocyanide complexes are used in medical imaging.

<span class="mw-page-title-main">Ferrole</span> Class of chemical compounds

In organoiron chemistry, a ferrole is a type of diiron complex containing the (OC)3FeC4R4 heterocycle that is pi-bonded to a Fe(CO)3 group. These compounds have Fe-Fe bonds (ca. 252 pm) and semi-bridging CO ligands (Fe-C distances = 178, 251 pm). They are typically air-stable, soluble in nonpolar solvents, and red-orange in color.

<span class="mw-page-title-main">Metallaborane</span>

In chemistry, a metallaborane is a compound that contains one or more metal atoms and one or more boron hydride. These compounds are related conceptually and often synthetically to the boron-hydride clusters by replacement of BHn units with metal-containing fragments. Often these metal fragments are derived from metal carbonyls or cyclopentadienyl complexes. Their structures can often be rationalized by polyhedral skeletal electron pair theory. The inventory of these compounds is large, and their structures can be quite complex.

Trimethylenemethane complexes are metal complexes of the organic compound trimethylenemethane. Several examples are known, and some have been employed in organic synthesis.

In organometallic chemistry, (diene)iron tricarbonyl describes a diverse family of related coordination complexes consisting of a diene ligand coordinated to a Fe(CO)3 center. Often the diene is conjugated, e.g., butadiene, but the family includes nonconjugated dienes as well. The compounds are yellow, air-stable, often low-melting, and soluble in hydrocarbon solvents. The motif is so robust that even unstable dienes form easily characterized derivatives, such as norbornadienone and cyclobutadiene.

The stabilization of bismuth's +3 oxidation state due to the inert pair effect yields a plethora of organometallic bismuth-transition metal compounds and clusters with interesting electronics and 3D structures.

<span class="mw-page-title-main">Disulfidobis(tricarbonyliron)</span> Chemical compound

Disulfidobis(tricarbonyliron), or Fe2(μ-S2)(CO)6, is an organometallic molecule used as a precursor in the synthesis of iron-sulfur compounds. Popularized as a synthetic building block by Dietmar Seyferth, Fe2(μ-S2)(CO)6 is commonly used to make mimics of the H-cluster in [FeFe]-hydrogenase. Much of the reactivity of Fe2(μ-S2)(CO)6 proceeds through its sulfur-centered dianion, [Fe2(μ-S)2(CO)2]2-.

References

  1. Dewar, J., & Jones, H. O. (1907). On a New Iron Carbonyl, and on the Action of Light and of Heat on the Iron Carbonyls. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 79(527), 66–80. doi:10.1098/rspa.1907.0015
  2. Diiron nonacarbonyl, reactivity
  3. Elschenbroich, C.; Salzer, A. ”Organometallics : A Concise Introduction” (2nd Ed) (1992) Wiley-VCH: Weinheim. ISBN   3-527-28165-7
  4. Edmund Speyer; Hans Wolf (1924). "Über die Bildungsweise von Eisen-nonacarbonyl aus Eisen-pentacarbonyl". Berichte der Deutschen Chemischen Gesellschaft. 60 (6): 1424–1425. doi:10.1002/cber.19270600626.
  5. 1 2 King, R. B. Organometallic Syntheses. Volume 1 Transition-Metal Compounds; Academic Press: New York, 1965. ISBN   0-444-42607-8.
  6. E. H. Braye; W. Hübel (1966). "Diiron Enneacarbonyl". Inorganic Syntheses. Vol. 8. pp. 178–181. doi:10.1002/9780470132395.ch46. ISBN   978-0-470-13239-5.{{cite book}}: |journal= ignored (help)
  7. Jennifer C. Green, Malcolm L. H. Green, Gerard Parkin "The occurrence and representation of three-centre two-electron bonds in covalent inorganic compounds" Chem. Commun. 2012, 11481-11503. doi : 10.1039/c2cc35304k
  8. F. Albert Cotton, Jan M. Troup "Reactivity of diiron nonacarbonyl in tetrahydrofuran. I. Isolation and characterization of pyridinetetracarbonyliron and pyrazinetetracarbonyliron" J. Am. Chem. Soc., 1974, volume 96, pp 3438–3443. doi : 10.1021/ja00818a016
  9. Putnik, Charles F.; Welter, James J.; Stucky, Galen D.; d'Aniello, M. J.; Sosinsky, B. A.; Kirner, J. F.; Muetterties, E. L. (1978). "Metal clusters in catalysis. 15. A Structural and Chemical Study of a Dinuclear Metal Complex, Hexacarbonylbis(.eta.3-2-propenyl)diiron(Fe-Fe)". Journal of the American Chemical Society. 100 (13): 4107–4116. doi:10.1021/ja00481a020.
  10. Pettit, R.; Henery, J. (1970). "Cyclobutadieneiron Tricarbonyl". Organic Syntheses. 50: 21. doi:10.15227/orgsyn.050.0021.
  11. R. Noyori; Yokoyama, K.; Hayakawa, Y. (1988). "Cyclopentanones from α, α'-Dibromoketones and Enamines: 2,5-Dimethyl-3-Phenyl-2-Cyclopenten-1-one". Organic Syntheses ; Collected Volumes, vol. 6, p. 520.
  12. Domingos, A. J. P.; Howell, J. A. S.; Johnson, B. F. G.; Lewis, J. (1990). "Reagents for the Synthesis of η-Diene Complexes of Tricarbonyliron and Tricarbonylruthenium". Inorg. Synth. Inorganic Syntheses. Vol. 28. pp. 52–55. doi:10.1002/9780470132593.ch11. ISBN   9780470132593.
  13. Susan C. Fletcher; Martyn Poliakoff; James J. Turner (1986). "Structure and Reactions of Fe2(CO)8: An IR Spectroscopic study using 13C Photolysis with plane-polarized light, and matrix isolation". Inorg. Chem. 25 (20): 3597. doi:10.1021/ic00240a014.