Question

Draw the shapes of the various d orbitals and explain why they are split into two groups, i.e. t_2g and e_g in an octahedral field.

Answer 1

There five d-orbitals have the same energy. However, for octahedral complexes, when a ligands approaches a metal ion, it may experience opposition from the d-orbital electrons due to the geometric structure of the molecule. Further, the orbitals experience greater repulsion which lie along the axes from where ligands approach. Consequently, more energy is required to fill these orbitals compared to one of the other orbitals. Thus causes a splitting in the energy levels of the d-orbitals into t2g and eg.