Cyclopentadienyl ligand orbital interaction
= Cyclopentadienyl ligand orbital interaction
The five ring p orbitals form one nondegenerate and two doubly degenerate symmetry-adapted sets. About the ring normal, these match <metal> $d_{z^2}$, $(d_{xz},d_{yz})$, and $(d_{xy},d_{x^2-y^2})$ by sigma, pi and delta symmetry respectively. Matching symmetry permits interaction, but spatial overlap and energy separation determine its strength.