9.18 What is crystal field splitting energy? How does the magnitude of ∆o decide the actual configuration of d orbitals in a coordination entity?
The degenerate d-orbitals (in a spherical field environment) split into two levels i.e., and in the presence of ligands.
The splitting of the degenerate levels due to the presence of ligands is called the crystal-field splitting while the energy difference between the two levels ( and ) is called the crystal-field splitting energy. It is denoted by ∆o.
After the orbitals have split, the filling of the electrons takes place. After 1 electron (each) has been filled in the three orbitals, the filling of the fourth electron takes place in two ways.
It can enter the orbital (giving rise to like electronic configuration) or the pairing of the electrons can take place in the orbitals (giving rise to like electronic configuration).
If the ∆o value of a ligand is less than the pairing energy (P), then the electrons enter the orbital. On the other hand, if the ∆o value of a ligand is more than the pairing energy (P), then the electrons enter the orbital.