Difference between revisions 6001623 and 6001624 on simplewiki

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| ImageFileL1 = Ferrocene-2D.png
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| ImageFileR1 = Ferrocene-from-xtal-3D-balls.png
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| ImageFile2 = Photo of Ferrocene (powdered).JPG
(contracted; show full)

The carbon-carbon bond distances are 1.40 Å within the five membered rings, and the Fe-C bond distances are 2.04 Å.

==Synthesis and handling properties==
The first reported<ref>{{cite journal|year=1951|last1=Kealy|first1=T. J.|last2=Pauson|first2=P. L.|journal=
[[Nature (journal)|Nature]]|volume=168|pages=1039}}</ref> synthesis of ferrocene used the [[Grignard reagent]] cyclopentadienyl magnesium bromide, which can be prepared by reacting [[cyclopentadiene]] with magnesium and [[bromoethane]] in [[anhydrous]] [[benzene]].  [[Iron(II) chloride]] is then suspended in anhydrous [[diethyl ether]] and added to the Grignard reagent.  The reaction sequence is:

:2 C<sub>5</sub>H<sub>5</sub>MgBr + FeCl<sub>2</sub> &rarr; Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub> + MgCl<sub>2</sub> + MgBr<sub>2</sub>

Numerous other syntheses have been reported, including the direct reaction of [[gas]]-phase cyclopentadiene with metallic iron<ref>{{cite journal|year=1954|last1=Wilkinson|first1=G.|authorlink1=Geoffrey Wilkinson|last2=Pauson|first2=P. L.|last3=Cotton|first3=F. A.|journal=Journal of the American Chemical Society[[J. Am. Chem. Soc.]]|volume=76|pages=1970}}</ref> at 350 °C or with [[iron pentacarbonyl]].<ref>{{cite journal|year=1959|last1=Wilkinson|first1=G.|authorlink1=Geoffrey Wilkinson|last2=Cotton|first2=F. A.|journal=Progress in Inorganic Chemistry|volume=1|pages=1-124}}</ref>⏎
[[Image:Ferrocene 3d model 2.png|thumb|right|A space-filling model of the [[staggered conformation]] of ferrocene.]]

:Fe + 2 C<sub>5</sub>H<sub>6</sub>(g) &rarr; Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub> + H<sub>2</sub>(g)

:Fe(CO)<sub>5</sub> + 2 C<sub>5</sub>H<sub>6</sub>(g) &rarr; Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub> + 5 CO(g) + H<sub>2</sub>(g)

[[Image:Ferrocene 3d model 2.png|thumb|right|A space-filling model of ferrocene.]]⏎
More efficient preparative methods are generally a modification of the original [[transmetalation]] sequence using either commercially available [[sodium cyclopentadienide]]<ref>{{OrgSynth|title = Ferrocene|author = [[Geoffrey Wilkinson]]|collvol = 4|collvolpages = 473|year = 1963|prep = cv4p0473}}</ref> or freshly [[dicyclopentadiene|cracked]] cyclopentadiene and [[potassium hydroxide]]<ref>Jolly, W. L., The Synthesis and Characterization of Inorganic Compounds, Prentice-Hall: New Jersey, 1970.</ref> with anhydrous iron(II) chloride in ethereal solvents:

: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

:FeCl<sub>2</sub>.4H<sub>2</sub>O + 2 C<sub>5</sub>H<sub>6</sub> + 2 KOH &rarr; Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub> + 2 KCl + 6 H<sub>2</sub>O

Direct transmetalation can also be used to prepare ferrocene from other metallocenes, such as [[manganocene]]:<ref>{{cite journal |last1= Wilkinson|first1= G.|authorlink1= Geoffrey Wilkinson|last2= Cotton|first2= F. A.|last3= Birmingham|first3= J. M.|year= 1956|title= |journal= J. Inorg. Nucl. Chem.|volume= 2|issue= |pages= 95|url= |doi= }}</ref>

:FeCl<sub>2</sub> + Mn(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub> &rarr; MnCl<sub>2</sub> + Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>⏎
⏎
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 fer(contracted; show full)[[ru:Ферроцен]]
[[fi:Ferroseeni]]
[[sv:Ferrocen]]
[[th:เฟอร์โรซีน]]
[[tr:Ferrosen]]
[[uk:Фероцен]]
[[ur:Ferrocene]]
[[zh:二茂铁]]