Question

What is crystal field stabilization energy? Explain with an example.

Answer 1

A consequence of Crystal Field Theory is that the distribution of electrons in the orbitals can lead to stabilisation for some electron configurations. It is a simple matter to calculate the stabilization since all that is needed is the electron configuration. For an octahedral complex, an electron in the more stable $t_2\left(g\right)$ subset is treated as contributing $-\frac{2}{5}\Delta$ whereas an electron in the higher energy $e_g$ subset contributes to a destabilisation of $\frac{3}{5}\Delta$
The final answer is then expressed as a multiple of the crystal field splitting parameter $\Delta$ (Delta)
Based on this, the crystal field stabilisation energies for $d^0$ to $d^{10}$ configurations can then be used to calculate the Octahedral Site Preference Energies which is defined as OSPE = CFSE (oct) - CFSE (tet)
Note: The conversion between ${\Delta }_{oct}$ and ${\Delta }_{tet}$ used for these calculations is
${\Delta }_{tet}={\Delta }_{oct}\times \frac{4}{9}$