If the crystal field splitting energy () is strictly less than the pairing energy (), what will be t — Coordination Compounds Chemistry Question

💡 Solution & Explanation

If $\Delta_o < P$, the energy required to pair electrons in the same orbital is greater than the energy required to jump the energy gap ($\Delta_o$) into the higher $e_g$ orbitals. Thus, after placing one electron in each of the three $t_{2g}$ orbitals (Hund's rule), the fourth electron will enter the higher $e_g$ level rather than pairing up. This creates a high-spin complex with the configuration $t_{2g}^3 e_g^1$.