Ferrocene
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| General | |
|---|---|
| Discovered | 1951 |
| Systematic | bis(η5-cyclopentadienyl)iron(II) |
| Name | Ferrocene, iron cyclopentadienyl |
| Chemical formula | Fe(C5H5)2 |
| Data | |
| Formula weight | 186,04 amu |
| Melting point | 174–176°C (447–449 K) |
| Boiling point | 249°C (522 K) |
| Density | 1,490 g/m3 (20°C) |
| Crystal structure | ? |
| Solubility | insoluble in water and soluble in organic solvents |
| Thermochemistry | |
| ΔfH0gas | |
| ΔfH0liquid | |
| ΔfH0solid | |
| S0solid | |
| Safety | |
| Ingestion | ? |
| Inhalation | ? |
| Skin | ? |
| Eyes | ? |
| More info | Hazardous Chemical Database (http://ull.chemistry.uakron.edu/erd/chemicals1/9/8391.html) |
Ferrocene Fe(C5H5)2 is the prototypical metallocene, a type of organometallic chemical compound, consisting of two cyclopentadienyl rings bound on opposite sides of a central iron atom and forming an organometallic sandwich compound.
It was first made unintentionally from the reaction of cyclopentadiene and iron powder in the 1950s, originally designed to couple the diene. Instead a lightly orange powder was obtained. The structure was confirmed by NMR. Discovery of its structure led to an explosion of interest in d-block metal carbon bonds and brought about the development and the now flourishing study of organometallic chemistry.
In ferrocene, the pi electrons of both aromatic cyclopentadienyl rings are shared with the central iron ion, giving it an inert gas electron configuration. This makes ferrocene particularly stable.
Ferrocene finds practical application as a catalyst in the making of ultra-high molecular weight polyethylene. This material is a new alternative to aramid, both can be used to make fibres for bulletproof clothing.
Ferrocene demonstrates electrochemically reversible one-electron redox behavior, and ferrocenium ion, which is formed by oxidation of ferrocene, is also stable in the air and easy to handle. Moreover, the redox behavior of ferrocene is hardly influenced by external factors such as temperature and solvents. This is because the HOMO (a’1g) and HOMO-1(e2g) orbitals of ferrocene have almost non-bonding characteristics, and the change of the coordination environment around the iron center by oxidation is small. This stable redox behavior makes ferrocene an attractive molecule for both basic study and applications. And since the cyclopentadienyl rings of ferrocene have aromaticity just like benzene and the reactivities of both molecules are similar to each other, a substitution group can be easily introduced to ferrocene by using an organosynthetic method.
For these reasons, a large number of compounds utilizing ferrocene have been synthesized and their properties have been studied. Among these compounds, the development of redox-responsive molecules as molecular devices is of great interest now.de:Ferrocen ja:フェロセン sv:Ferrocen