Why do transition metals have variable oxidation states?

1 Answer
Jan 15, 2018

Well, they have many orbitals of similar energy... so they can use them.


The possible oxidation states have already been shown here.

The d-block transition metals often use #d# and #s# orbitals to bond... such as in #pi# back-bonding shown here...

https://upload.wikimedia.org/

...and the f-block transition metals often use #f#, #d#, and #s# orbitals to bond...

http://pubs.rsc.org/en/Content/ArticleHtml/2016/DT/c6dt00634e

[This is the uranium complex known as tris(cyclopentadienyl)tert-butylisocyanouranium(III).]

Hence, the large pool of valence orbitals allow a flexible selection of oxidation states.