Ferrocene

Properties

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

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 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.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Ferrocene has a wide range of uses, it has been shown that the addition of ferrocene (and ferrocene derivatives) to diesel fuel reduces the emission of soot from the engine, and the addition of ferrocene to gasoline increases the octane rating. A mixture of compounds including ferrocene is used as a tetraalkyl lead replacement for vintage cars which need 'leaded' petrol. It has been found that ferrocenium salts have an anticancer activity, and a drug has been reported which is a ferrocenyl version of tamoxafin. The idea behind this drug is to create a drug which will bind to the estrogen receptor in cancer cells which also contains a cytotoxic side group. It has also been shown that ferrocene can be used as a poison to kill slugs. In a study it was found that simple iron salts are able to kill slugs, but on contact with soil these compounds were inactivated; however ferrocene on the surface of soil was found to be effective as a slug killer.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Chemical: REDIRECT Chemical substance...

Cyclopentadienyl: REDIRECT Cyclopentadienyl complex...

Iron: Iron is a chemical element in the periodic table that has the symbol Fe (L.: Ferrum) and atomic number 26. Iron is a group 8 and period 4 metal. Iron is notable for being the final element produced by stellar nucleosynthesis, and thus the heaviest element which does not require a supernova or simil...