Difference between revisions 6001595 and 6001596 on simplewiki

{{chembox
| Watchedfields = changed
| verifiedrevid = 310175235
| ImageFileL1 = Ferrocene-2D.png
| ImageSizeL1 = 80 px
| ImageFileR1 = Ferrocene-from-xtal-3D-balls.png
| ImageSizeR1 = 120 px
| ImageFile2 = Photo of Ferrocene (powdered).JPG
(contracted; show full)
 | journal = [[e-Journal of Surface Science and Nanotechnology]]
 | year = 2008
 | volume = 6
 | pages = 119–123
 | doi = 10.1380/ejssnt.2008.119}}</ref><ref>[http://www.jstage.jst.go.jp/article/ejssnt/6/0/119/_pdf Self-Assembling Properties of 11-Ferrocenyl-1-Undecanethiol on Highly Oriented Pyrolitic Graphite Characterized by Scanning Tunneling Microscopy]}}</ref>

The carbon-carbon bond distances are 1.40 Å within the five membered rings, and the 
bond distances between the sandwiched iron and the carbons of the rings are 2.04 Å.

==Physical properties==
[[Image:Ferrocene 3d model 2.png|thumb|right|A space-filling model of ferrocene.]]
Ferrocene is an [[air]]-stable orange solid that readily [[Sublimation (physics)|sublime]]s, especially upon heating in a vacuum.  As expected for a symmetric and uncharged species, ferrocene is soluble in normal organic solvents, such as benzene, but is insoluble in water.  It is stable to temperatures as high as 400 °C.<ref>Solomons, Graham, and Craig Fryhle. Organic Chemistry. 9th ed. USA: John Wiley & Sons, Inc., 2006.</ref>

The following table gives typical values of vapor pressure of ferrocene at different temperatures:<ref>Monte, M. J. S.; Santos, L. M. N. B. F.; Fulem, M.; Fonseca, J. M. S. & Sousa, C. A. D.,  New static apparatus and vapor pressure of reference materials: Naphthalene, benzoic acid, benzophenone, and ferrocene,  [[J. Chem. Eng. Data]], 2006, 51, 757-766</ref>

{| class="wikitable"
|-
! pressure(Pa)
! 1
! 10
! 100
|-
| temperature(K)
| 298
| 323
| 353
|}

==Preparation==
Ferrocene is efficiently prepared by the reaction of [[sodium cyclopentadienide]] with anhydrous [[iron(II) chloride|ferrous chloride]] in ethereal solvents:<ref>{{OrgSynth | title = Ferrocene | author = [[Geoffrey Wilkinson]] | collvol = 4 | collvolpages = 473 | year = 1963 | prep = cv4p0473}}</ref>
:2 NaC<sub>5</sub>H<sub>5</sub>  +  FeCl<sub>2</sub>   →   Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>  +  2 NaCl

==Reactions==
===With electrophiles===

Ferrocene undergoes many reactions characteristic of aromatic compounds, enabling the preparation of substituted derivatives.  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 preparation of phosphorus derivatives of ferrocenes are illustrative.  IFe-C bond distances are 2.04 Å.

==Synthesis and handling properties==
Ferrocene is efficiently prepared by the reaction of [[sodium cyclopentadienide]] with anhydrous [[iron(II) chloride|ferrous chloride]] in ethereal solvents:<ref>{{OrgSynth | title = Ferrocene | author = [[Geoffrey Wilkinson]] | collvol = 4 | collvolpages = 473 | year = 1963 | prep = cv4p0473}}</ref>
:2 NaC<sub>5</sub>H<sub>5</sub>  +  FeCl<sub>2</sub>   →   Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>  +  2 NaCl
[[Image:Ferrocene 3d model 2.png|thumb|right|A space-filling model of ferrocene.]]
As expected for a symmetric and uncharged species, ferrocene is soluble in normal organic solvents, such as benzene, but is insoluble in water.  Ferrocene is an [[air]]-stable orange solid that readily [[Sublimation (physics)|sublime]]s, especially upon heating in a vacuum.  It is stable to temperatures as high as 400 °C.<ref>Solomons, Graham, and Craig Fryhle. Organic Chemistry. 9th ed. USA: John Wiley & Sons, Inc., 2006.</ref>  The following table gives typical values of vapor pressure of ferrocene at different temperatures:<ref>Monte, M. J. S.; Santos, L. M. N. B. F.; Fulem, M.; Fonseca, J. M. S. & Sousa, C. A. D.,  New static apparatus and vapor pressure of reference materials: Naphthalene, benzoic acid, benzophenone, and ferrocene,  [[J. Chem. Eng. Data]], 2006, 51, 757-766</ref>
{| class="wikitable"
|-
! pressure(Pa)
! 1
! 10
! 100
|-
| temperature(K)
| 298
| 323
| 353
|}

==Reactions==
===With electrophiles===
Ferrocene undergoes many reactions characteristic of aromatic compounds, enabling the preparation of substituted derivatives.  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.
[[Image:FcGen'l.png|400px|thumb|center|Important reactions of ferrocene with electrophiles and other reagents.]]

===Lithiation===
Ferrocene reacts readily with [[butyl lithium]] to give 1,1'-dilithioferrocene, which in turn is a versatile [[nucleophile]]. This approach is especially useful method to introduce main group functionality, e.g. using S8, chlorophosphines, chlorosilanes.  The strained compounds undergo [[ring-opening polymerization]].<ref>David E. Herbert, Ulrich F. J. Mayer, Ian Manners “Strained Metallocenophanes and Related Organometallic Rings Containing pi-Hydrocarbon Ligands and Transition-Metal Centers”  Angew. Chem. Int. Ed. 2007, volume 46, 5060 - 5081.   {{DOI|10.1002/anie.200604409}}</ref>

[[Image:FcLi2chem.png|450px|thumb|center|Some transformations of dilithioferrocene.]]

===Phosphorus derivatives===
Many phosphine derivatives of ferrocenes are known and some are used in commericalized processes.  Simplest and best known is [[1,1'-Bis(diphenylphosphino)ferrocene|1,1'-bis(diphenylphosphino)ferrocene]] (dppf) prepared from dilithioferrocene.  Other routes to such ligands are known.  For example, in the presence of [[aluminium chloride]]  Me<sub>2</sub>NPCl<sub>2</sub> and ferrocene react to give ferrocenyl dichloro[[phosphine]],<ref>{{cite journal
 | title = Ferrocene derivatives. 27. Ferrocenyldimethylphosphine
 | author = G.R. Knox, P.L. Pauson and D. Willison
 | journal = Organometallics
 | volume = 11
 | issue = 8
 | pages = 2930 &ndash; 2933
 | year = 1992
 | doi = 10.1021/om00044a038
}}</ref>
while treatment with [[phenyldichlorophosphine]] under similar conditions forms ''P,P''-diferrocenyl-''P''-phenyl phosphine.<ref>{{cite journal
 | author = G.P. Sollott, H.E. Mertwoy, S. Portnoy and J.L. Snead
 | title = Unsymmetrical Tertiary Phosphines of Ferrocene by Friedel-Crafts Reactions. I. Ferrocenylphenylphosphines 
 | journal = J. Org. Chem.
 | year = 1963 
 | volume = 28 
 | pages = 1090 &ndash; 1092
 | doi = 10.1021/jo01039a055
}}</ref>⏎
⏎
  In common with [[anisole]] the reaction of ferrocene with P<sub>4</sub>S<sub>10</sub> forms a dithiadiphosphetane disulfide.<ref>{{cite journal
 | title = 2,4-Diferrocenyl-1,3-dithiadiphosphetane 2,4-disulfide; structure and reactions with catechols and [PtCl<sub>2</sub>(PR<sub>3</sub>)<sub>2</sub>](R = Et or Bun)
 | author = Mark R. St. J. Foreman, Alexandra M. Z. Slawin and J. Derek Woollins
 | journal = J. Chem. Soc., Dalton Trans., 
 | year = 1996
 | pages =  3653 &ndash; 3657
 | doi = 10.1039/DT9960003653
}}</ref>

[[Image:FcGen'l.png|400px|thumb|center|Important reactions of ferrocene with electrophiles and other reagents.]]

===Lithiation===

Ferrocene reacts readily with [[butyl lithium]] to give 1,1'-dilithioferrocene, which in turn is a versatile [[nucleophile]]. This approach is especially useful method to introduce main group functionality, e.g. using S8, chlorophosphines, chlorosilanes.  Related diphosphines are used as ligands in commerically useful processes.  The strained compounds undergo [[ring-opening polymerization]].<ref>David E. Herbert, Ulrich F. J. Mayer, Ian Manners “Strained Metallocenophanes and Related Organometallic Rings Containing pi-Hydrocarbon Ligands and Transition-Metal Centers”  Angew. Chem. Int. Ed. Angew Chem. Int. Ed. Engl. 2007, 46, 5060 - 5081.   {{DOI|10.1002/anie.200604409}}</ref>

[[Image:FcLi2chem.png|450px|thumb|center|Some transformations of dilithioferrocene.]]⏎
⏎
===Redox chemistry===⏎
{{main|Ferrocenium}}
Unlike the majority of hydrocarbons, ferrocene undergoes a one-electron oxidation at a low potential, around 0.5 V ''vs''. a [[saturated calomel electrode]] (SCE). It is also been used as standard in electrochemistry as Fc+/Fc = 0.64 V vs. NHE. Some [[electron]] rich hydrocarbons (e.g., [[aniline]]) also are oxidized at low potentials, but only irreversibly. Oxidation of ferrocene gives a stable cation called ferrocenium. On a preparative scale, the oxidation is conveniently effected wi(contracted; show full)[[pl:Ferrocen]]
[[ru:Ферроцен]]
[[fi:Ferroseeni]]
[[sv:Ferrocen]]
[[th:เฟอร์โรซีน]]
[[tr:Ferrosen]]
[[ur:Ferrocene]]
[[zh:二茂铁]]