# Coordination number in π-complexes

I wanted to know what is the coordination number of the metal atom in π-complexes like Zeise's salt, ferrocene and dibenzene chromium.
I found some data on it but its a bit contradicting. Can anyone tell me what's right exactly cause what I found on web is a bit different from what my teacher said. It would be great if someone also tells me the reason and way of finding the coordination numbers in such compounds.

• You should link your research here. – user98209 Aug 26 '20 at 9:05
• I found the answer for coordination number of zeise's salt on this website sarthaks.com/242855/… , Wikipedia didn't give me any useful result.....it just said 'wherein the platinum is three-coordinate and in oxidation state 0 (Zeise's salt is a derivative of platinum(II)).' – Priyank Aug 26 '20 at 9:25
• And coming to the other two salts according to Wikipedia the LBN is 5 and 6 whereas the coordination number is 10 and 12. When I read about LAN I found it to be the same😅. And my teacher says that the coordination number is 5 and 6. So I dunno what's right or wrong. – Priyank Aug 26 '20 at 9:28
• Your teacher must have told about the hapticity which is 5,6. Also, the answer provided on sarthaks is wrong . if hat were the case the EAN of ferrocene would be 22 and that would be epic. In reality the EAN of ferrocene is 36, considering the two rings of hapticity five which have an effective contribution of 10e – user98209 Aug 26 '20 at 10:03
• yes, since it has hapticity 5 and two rings, the total number of atoms coordinated is 10 ; EAN= 26 + number of electron taken from ligand which is 10 in this case. If you go by the definition "the number of atoms or ions immediately surrounding a central atom in a complex or crystal." , then CN would be 5 – user98209 Aug 26 '20 at 11:03