Ferrocene
IUPAC name	bis(η5-cyclopentadienyl)iron(II)
Other names	ferrocene, iron cyclopentadienyl
Identifiers
CAS number	[102-54-5]
PubChem	11985121
Properties
Molecular formula	C10H10Fe
Molar mass	186.04 g/mol
Appearance	light orange powder
Density	1.49 g/cm3 (20 °C)
Melting point	174-176 °C Image File history File links Download high resolution version (530x730, 5 KB) Summary Self-made in ChemDraw 8. ... Image File history File links Download high resolution version (1211x1051, 113 KB) Summary A 3D-model of a ferrocene molecule. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... PubChem is a database of chemical molecules. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... In physics, density is defined as mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ...
Boiling point	249 °C The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ...
Solubility in water	Insoluble in water, soluble in most organic solvents
Related Compounds
Related compounds	cobaltocene, nickelocene, chromacene, bis(benzene)chromium
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Ferrocene is the chemical compound with the formula Fe(C₅H₅)₂. Ferrocene is the prototypical metallocene, a type of organometallic chemical compound consisting of two cyclopentadienyl rings bound on opposite sides of a central metal atom. Such organometallic compounds are also known as sandwich compounds.^[1] Solubility refers to the ability for a given substance, the solute, to dissolve in a solvent. ... Impact of a drop of water Water is a chemical substance that is essential to all known forms of life. ... Cobaltocene, Co(C5H5)2, also known as bis(cyclopentadienyl)cobalt(II), belongs to a group of organometallic compounds called metallocenes which consist of a metal ion sandwiched between two cyclopentadienyl (Cp) rings. ... Nickelocene, Ni(C5H5)2, also known as biscyclopentadienylnickel(II), belongs to a group of organometallic compounds called metallocenes which consist of a metal ion sandwiched between two cyclopentadienyl (cp) rings. ... Chromocene is an organometallic compound with the formula Cr(C5H5)2. ... Bis(benzene)chromium is the chemical compound with the formula Cr(η6-C6H6)2. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... A chemical compound is a chemical substance consisting of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. ... In chemistry, and in particular, in organometallic chemistry, a metallocene is a compound consisting of an aromatic organic ligand bound to a metal. ... n-butyllithium, an organometallic compound. ... This article or section includes a list of works cited but its sources remain unclear because it lacks in-text citations. ... A cyclopentadienyl complex is a metal complex with one or more cyclopentadienyl groups (C5H5-, abbreviated as Cp). ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily loses electrons to form positive ions (cations) and has metallic bonds between metal atoms. ... An organometallic compound is partially characterized by the presence of one or more metal-carbon bonds, in which the carbon involved would, apart from the metal-carbon bond, be otherwise considered a part of an organic compound. ... Space-filling model of ferrocene, the archetypal sandwich compound A sandwich compound in organometallic chemistry is any chemical compound containing a metal atom sandwiched between two arene units. ...

History

Ferrocene, like many chemical compounds, was first prepared unintentionally. In 1951, Pauson and Kealy at Duquesne University reported the reaction of cyclopentadienyl magnesium bromide and ferric chloride with the goal of oxidatively coupling the diene. Instead, they obtained a light orange powder of "remarkable stability." Ferrocene is more efficiently prepared by the reaction of sodium cyclopentadienyl with anhydrous ferrous chloride in ethereal solvents. R-phrases , S-phrases , Related Compounds Other anions Iron(III) fluoride Iron(III) bromide Other cations Iron(II) chloride Manganese(II) chloride Cobalt(II) chloride Ruthenium(III) chloride Related coagulants Iron(II) sulfate Polyaluminium chloride Except where noted otherwise, data are given for materials in their standard state (at 25... Iron(II) chloride, or ferrous chloride, is the chemical compound FeCl2. ...

Sir Geoffrey Wilkinson of Imperial College London shared a Nobel Prize for his work on ferrocene. Ferrocene's structure was confirmed by NMR spectroscopy and X-ray crystallography.^[2] Its distinctive "sandwich" structure led to an explosion of interest in compounds of d-block metals with hydrocarbons, and initiated the development of the now flourishing study of organometallic chemistry. Many other metals can be used in place of iron and many other hydrocarbons can be used instead of cyclopentadiene to form altered Cp ligands which are then attached to iron. For instance indene can be used in place of the cyclopentadiene to form bisbenzoferrocene.^[3]. Sir Geoffrey Wilkinson was an English chemist He was born 14 July 1921 in the village of Springside, near Todmorden in Yorkshire. ... Imperial College London is a university in London and is one of the United Kingdoms best-known scientific academic institutions. ... Pacific Northwest National Laboratorys high magnetic field (800 MHz, 18. ... X-ray crystallography or single-crystal X-ray diffraction is an analytical technique which uses the diffraction pattern produced by bombarding a single crystal with X-rays to solve the crystal structure. ... D Block is a rap group based in Yonkers, New York. ... Indene is a flammable polycyclic hydrocarbon with chemical formula C9H8 and CAS number 95-13-6. ...

In addition it is possible by heating [Fe(η⁵-C₅H₅)(CO)₂(η¹-pyrrole)] in cyclohexane to form the pyridine version of ferrocene [Fe(η⁵-C₅H₅)(η⁵-C₄H₄N)].^[4]. This compound on boiling under reflux in benzene is converted to ferrocene.^[5] Cyclohexane is a cycloalkane with the molecular formula C6H12. ... Pyridine is a chemical compound with the formula C5H5N. It is a liquid with a distinctively putrid odour. ... Diagram of typical reflux apparatus. ... Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ...

In ferrocene, the six π-electrons of each aromatic cyclopentadienyl anion are shared with the central Fe²⁺ ion, resulting in an inert gas electron configuration. This configuration makes ferrocene particularly stable. In chemistry, an aromatic molecule is one in which electrons are free to cycle around circular arrangements of atoms, which are alternately singly and doubly bonded to one another. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... The valence shells of a transition metal can accommodate 18 electrons: 2 in each of the five d orbitals, to give 10 in total; 2 in each of the 3 p orbitals, to give 6 in total; and 2 in the s orbital (see Electron counting). ...

Physical properties

Ferrocene is an air stable orange solid that readily sublimes in vacuum or when heated. As expected for a symmetric and uncharged species, ferrocene is soluble in normal organic solvents, such as benzene, but is insoluble in water. Layers of Atmosphere (NOAA) Air redirects here. ... Sublimation of an element or substance is a conversion between the solid and the gas phases with no intermediate liquid stage. ...

Chemical properties

Ferrocene undergoes many reactions characteristic of aromatic compounds, enabling the preparation of derivatives (substituted ferrocenes). Most common substitution patterns are 1-substituted (one substituent on one ring), 1,1'-disubstituted (1 H of each ring is replaced by a substituent), and 1,2-disubstituted (two substituents on the same ring). For example the reaction of ferrocene, aluminium chloride and Me₂NPCl₂ in hot heptane forms dichloroferrocenyl phosphine,^[6] while treatment with phenyldichlorophosphine under similar conditions forms P,P-diferrocenyl-P-phenyl phosphine.^[7] In common with anisole the reaction of ferrocene with P₄S₁₀ forms a dithiadiphosphetane disulfide.^[8] Aluminium chloride (AlCl3) is a compound of aluminium and chlorine. ... R-phrases , , , , S-phrases , , , , , , , Flash point −4 °C Autoignition temperature 285 °C Explosive limits 1. ... Phosphine is the common name for phosphorus hydride (PH3), also known by the IUPAC name phosphane and, occasionally, phosphamine. ... Anisole, also known as methoxybenzene, is a clear, colorless liquid with a pleasant smell similar to that of anise seed. ...

A common undergraduate experiment is the Friedel-Crafts reaction of ferrocene with acetic anhydride (or acetyl chloride) in the presence of phosphoric acid as a catalyst: The Friedel-Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877. ... Acetic anhydride, also known as ethanoic anhydride, is one of the simplest of acid anhydrides. ... Acetyl chloride, also known as ethanoyl chloride, is an acid chloride derived from acetic acid. ... Phosphoric acid, also known as orthophosphoric acid or phosphoric(V) acid, is an inorganic mineral acid having the chemical formula H3PO4. ...

Fe(C₅H₅)₂ + (CH₃CO)₂O → Fe(C₅H₅)(C₅H₄C(O)CH₃) + CH₃CO₂H

Fe(C₅H₅)(C₅H₄C(O)CH₃) + (CH₃CO)₂O → Fe(C₅H₄C(O)CH₃)₂ + CH₃CO₂H

Ferrocene is readily deprotonated, e.g. by butyl lithium, to give 1,1'-dilithioferrocene, which in turn is a versatile nucleophile. An organolithium reagent is a carbon nucleophile similar to a Grignard reagent. ... In chemistry, a nucleophile (literally nucleus lover) is a reagent which is attracted to centres of positive charge. ...

Fe(C₅H₅)₂ + 2 C₄H₉Li → Fe(C₅H₄Li)₂ + 2 C₄H₁₀

Fe(C₅H₄Li)₂ + 2 (C₆H₅)₂PCl → Fe(C₅H₄P(C₆H₅)₂)₂ + 2 LiCl

Unlike the majority of aromatic hydrocarbons, ferrocene can undergo one-electron oxidation at a low potential, around. 0.4 V vs. a saturated calomel electrode (SCE) (N.B. electron rich aromatic amines such as aniline, the heterocycles pyrrole and thiophene can be oxidized with ease by electrochemical means). Ferrocene can be oxidized using FeCl₃ to give the blue-colored ferrocenium ion, [Fe(C₅H₅)₂]⁺, which is often isolated as its [PF₆]⁻ salt. Ferrocenium salts are a widely used oxidizing agent, in part because the redox product ferrocene is so inert and readily separated from the products.^[9] The Saturated calomel electrode (SCE) is a reference electrode which uses the reaction between mercury metal and mercury(I) chloride, to fix its potential. ... e- redirects here. ... Aniline, phenylamine or aminobenzene (C6H5NH2) is an organic chemical compound which is a primary aromatic amine consisting of a benzene ring and an amino group. ... Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ... Thiophene is an aromatic heterocyclic compound consisting of four carbon atoms and one sulfur atom in a five-membered ring. ...

Applications of ferrocene and its derivatives

Ferrocene itself has few applications. However, known synthetic methods allow the preparation of countless of derivatives, such as mono- and disubstituted ferrocenes, thus extending the range of applications.

Fuel additives

Ferrocene and its derivatives are antiknock agents used in the fuel for petrol engines; they are considered to be safer than tetraethyl lead, previously used.^[10] It is possible to buy at Halfords retail shop in UK, a petrol additive solution which contains ferrocene which can be added to unleaded petrol to enable it to be used in vintage cars which were designed to run on leaded petrol.^[11] Unfortunately, the iron containing deposits formed from ferrocene can form a conductive coating on the spark plug surfaces leading to spark plug failure. An antiknock agent is a gasoline additive used to reduce engine knocking and increase the fuels octane rating. ... Tetra-ethyl lead (also known as TEL, lead tetraethyl and tetraethyllead) is a toxic organometallic chemical compound, with formula (CH2CH3)4Pb, which was once used as a gasoline (petrol) additive. ... Halfords Group plc (LSE: HFD) is a leading retailer of car parts, car enhancement, cycles and travel solutions in the United Kingdom. ...

In diesel-fueled engines, ferrocene reduces the production of soot. Rudolf Christian Karl Diesel (1858-1913), inventor of the diesel engine. ...

Medical

Some ferrocenium salts exhibit anticancer activity, and an experimental drug has been reported which is a ferrocenyl version of tamoxifen.^[12] The idea is that the tamoxifen will bind to the estrogen binding sites, resulting cytotoxicity effect.^[13][14][15] Tamoxifen is an oral selective estrogen receptor modulator which is used in breast cancer treatment, and is currently the worlds largest selling breast cancer treatment. ... Estriol. ...

Materials chemistry

Ferrocene, being readily sublimed, can be used to deposit certain kinds of fullerenes, especially carbon nanotubes. Due to the fact that many organic reactions can be used to modify ferrocenes, it is the case that vinyl ferrocene can be made. The vinyl ferrocene can be made by a Wittig reaction of the aldehyde, a phosphonium salt and sodium hydroxide.^[16] The vinyl ferrocene can be converted into a polymer which can be thought of as a ferrocnyl version of polystyrene (the phenyl groups are replaced with ferrocenyl groups). Chemical structure of the vinyl functional group. ... The Wittig reaction is a chemical reaction of an aldehyde or ketone with a phosphonium ylide to give an alkene and triphenylphosphine oxide. ... An aldehyde. ... A phosphonium salt is a salt containing the phosphonium (PH4+) ion such as phosphonium iodide (PH4+I−). It may also refer to an organic derivative such as tetramethylphosphonium iodide, [P(CH3)4]+I−. Alkyltriphenylphosphonium salts are widely used for the preparation of Wittig reagents for the Wittig reaction. ... Sodium hydroxide (NaOH), also known as lye or caustic soda, is a caustic metallic base. ... Polystyrene is a polymer made from the monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum by the chemical industry. ...

As a ligand scaffold

Chiral ferrocenyl phosphines are employed as ligands for transition-metal catalyzed reactions. Some of them have found industrial applications in the synthesis of pharmaceuticals and agrochemicals. Phosphine is the common name for phosphorus hydride (PH3), also known by the IUPAC name phosphane and, occasionally, phosphamine. ...

1,1'-Bis(diphenylphosphino)ferrocene (dppf) is a diphosphine containing a ferrocene moiety; it is a valuable ligand for palladium coupling reactions. 1,1-Bis(diphenylphosphino)ferrocene, commonly abbreviated dppf, is a substituted phosphine commonly used, as are other phosphines, as a ligand in organometallic chemistry. ... Phosphine is the common name for phosphorus hydride (PH3), also known by the IUPAC name phosphane and, occasionally, phosphamine. ... A coupling reaction in organic chemistry is a catch-all for a range of reactions in Organometallic chemistry where two hydrocarbon radicals are coupled with the aid of a metal containing catalyst. ...

Variations

Because of the ease of substitution, many structurally unusual ferrocene derivatives have been prepared. For example, penta(ferrocenyl)cyclopentadienyl ligand ^[17], features a cyclopentadiene fitted with five ferrocene substituents.

In hexaferrocenylbenzene, all six positions on a benzene molecule have ferrocenyl substituents (R) ^[18]. X-ray diffraction analysis of this compound confirms that the cyclopentadienyl ligands are not co-planar with the benzene core but have alternating dihedral angles of +30° and −80°. Due to steric crowding the ferrocenyls are slightly bent with angles of 177° and have elongated C-Fe bonds. The quaternary cyclopentadienyl carbon atoms are also pyramidalized. ^[19] Image File history File links Download high resolution version (924x222, 7 KB) Summary Penta(ferrocenyl)cyclopentadienyl ligand Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ... X-ray crystallography is a technique in crystallography in which the pattern produced by the diffraction of x-rays through the closely spaced lattice of atoms in a crystal is recorded and then analyzed to reveal the nature of that lattice. ... In Aerospace engineering, the dihedral is the angle that the two wings make with each other. ... A generic trigonal planar molecule showing ideal bond angle. ...

References

Chemical & Engineering News is a weekly chemistry news magazine published by the American Chemical Society. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Chemical Reviews (usually abbreviated as ), is a peer-reviewed scientific journal, published since 1900 by the American Chemical Society. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Chemical & Engineering News is a weekly chemistry news magazine published by the American Chemical Society. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Angewandte Chemie or Angewandte Chemie International Edition is the chemistry journal of the Gesellschaft Deutscher Chemiker (Society of German Chemists). ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Chemical Communications or ChemComm is a is a peer-reviewed scientific journal in the chemical sciences published since 1996 by the Royal Society of Chemistry. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... The chair conformation is a term used for the most stable chemical conformation of a six membered single bonded carbon ring like cyclohexane. ... In molecular geometry, bond length or bond distance is the distance between two bonded atoms in a molecule. ... Picometre (American spelling: picometer) is an SI measure of length that is equal to 10−12 of a metre. ...

Further reading

Announcement of the discovery of ferrocene, but with wrong structure

• Kealy, T. J., Pauson, P. L. (1951). "A New Type of Organo-iron Compound". Nature 168: 1039-40. 
• Miller, S. A., Tebboth, J. A., Tremaine, J. F. (1952). "114. Dicyclopentadienyliron". Journal of the Chemical Society: 632-635. DOI:10.1039/JR9520000632. 

Announcement of the correct 'sandwich' structure

• Wilkinson, G., Rosenblum, M., Whiting, M. C., Woodward, R. B. (1952). "The Structure of Iron Bis-Cyclopentadienyl". Journal of the American Chemical Society 74: 2125-2126. 
• Fischer, E. O., Pfab, W. (1952). "{{{title}}}". Zeitschrift für Naturforschung B 7: 377-379. 

Others

• Dunitz, J. D., Orgel, L. E. (1953). "Bis-Cyclopentadienyl - A Molecular Sandwich". Nature 171: 121-122. 
• Pauson, P. L. (2001). "Ferrocene-how it all began". Journal of Organometallic Chemistry: 637-639. 
• Gerard Jaouen (ed.) (2006). Bioorganometallics: Biomolecules, Labeling, Medicine. Weinheim: Wiley-VCH. ISBN 978-3-527-30990-0.  (discussion of biological role of ferrocene and related compounds)

Nature is one of the most prominent scientific journals, first published on 4 November 1869. ... The Journal of the Chemical Society was a scientific journal published from 1862 to 1877. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Sir Geoffrey Wilkinson was an English chemist He was born 14 July 1921 in the village of Springside, near Todmorden in Yorkshire. ... Robert Burns Woodward (April 10, 1917–July 8, 1979) was an American organic chemist. ... The Journal of the American Chemical Society (usually abbreviated as , or JACS), is a peer-reviewed scientific journal, published since 1879 by the American Chemical Society. ... Nature is one of the most prominent scientific journals, first published on 4 November 1869. ...

External links

• Links to external chemical sources