In an octahedral crystal field, the interaction between ligands and the central metal ion's -orbital — Coordination Compounds Chemistry Question

💡 Solution & Explanation

In an octahedral field, ligands approach along the axes. The axial orbitals ($d_{x^2-y^2}, d_{z^2}$) experience direct repulsion and are raised in energy by $0.6 \Delta_o$ to form the $e_g$ set. To conserve energy around the hypothetical spherical barycentre, the three non-axial orbitals ($d_{xy}, d_{yz}, d_{zx}$) which lie between the axes experience less repulsion and are lowered in energy by $0.4 \Delta_o$ to form the $t_{2g}$ set.