How are the 10 vertical bonds in Ferrocene (sandwich structure) connected, by what type of bonds?
What is the real structure of ferrocene? Concerning the 10 vertical extra long bonds?
Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. It only takes a minute to sign up.Sign up to join this community
The "real" structure of ferrocene is an iron atom sandwiched between two flat, parallel, pentagonal C5H5 rings. The diagram above shows the atomic positions from a crystal structure but the bonds are merely a convenience and don't accurately summarize the way the bonding works though the picture does accurately summarize the atomic positions in the crystal structure.
The real bonding requires some understanding of molecular orbital theory and how the d-orbitals of iron interact with the delocalized pi-orbitals in the unsaturated ring. Some pictures of the orbitals contributing to the bonding are shown here.
The pictures we use can inspire questions that are more complicated than they have to be. I like the hamburger picture of ferrocene:
OK, there are some people who like a picture of some electron densities:
Without going into the mathematics of all the orbitals, you can see that the filled orbitals on cyclopentadienide ion will have two lobes to donate into d-orbitals on ferrous ion. And there will be an electrostatic attraction between the cyclopentadienide ions and the ferrous ion.
The use of points and lines connecting them distorts the filled-space reality of the actual molecule. Of course, when you look at the filled-space models, you can't see exact bond lengths and angles, but it may give you a better idea of atoms fitting together, with molecular orbitals providing some sort of glue.