Question

What is the maximum hapticity of cyclopentadienyl​ group?

• A. 5
• B. 6
• C. 3
• D. 2

Answer 1

The correct option is A 5

The number of carbon atoms of a ​ligand which are directly attached to ​(or closely associated with) the metal in ​a compound is called as the hapticity.​
For the 𝛑 -donor ligands​, Prefix like “${\eta }^x$'' is used.​
Where, η : Hapticity of the ligand​
x : Number of atoms attached ​to the metal atom/ion.​
$\pi -C_5{H}_5^{-}$: ${\eta }^5$- cyclopetadienyl​