Which of the following correctly expresses the relative magnitudes of crystal field splitting energi — Coordination Compounds Chemistry Question
Question
Which of the following correctly expresses the relative magnitudes of crystal field splitting energies for square planar ($\Delta_{sp}$), octahedral ($\Delta_o$), and tetrahedral ($\Delta_t$) complexes of the same metal and ligands?
💡 Solution & Explanation
The splitting energy depends heavily on geometry and the direction of ligand approach. - In square planar complexes, ligands approach directly along the x and y axes, intensely repelling the $d_{x^2-y^2}$ orbital, making $\Delta_{sp}$ the highest ($\Delta_{sp} \approx 1.3 \Delta_o$). - In octahedral complexes, 6 ligands approach along axes, leading to $\Delta_o$. - In tetrahedral complexes, only 4 ligands approach between the axes, so splitting is much weaker ($\Delta_t \approx 0.45 \Delta_o$). Therefore, $\Delta_{sp} > \Delta_o > \Delta_t$.