Crystal field theory d-orbital splitting in octahedral and tetrahedral complexes

1 Crystal field theory d-orbital splitting in octahedral and tetrahedral complexes 

The octahedral arrangement of six ligands surrounding a central metal ion. 

The electron density functions of the five d orbitals relative to the ligand positions in an octahedral complex. The gray and white regions in each orbital bear positive and negative signs, respectively. 

Orientations of the dx2 v2 and dXy orbitals with respect to the four ligands in a tetrahedral complex, looking down the z axis. Both d orbitals lie in the xy plane. Filled and open circles represent ligands that lie above and below the xy plane, respectively. It is obvious that the dx2 2 orbital is more favored for electron occupation in a tetrahedral complex. 

Similarly, when a metal ion is surrounded by four tetrahedrally arranged ligands, as shown in Figs. 8.1.3 and 8.1.4, it is not difficult to see that in this case the electrons tend to occupy the dz2 and dx2 y2 orbitals in preference to the other three orbitals, dxy, dK, and dxz. The splitting patterns for a set of d orbitals in octahedral and tetrahedral complexes are summarized in Fig. 8.1.5. 

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