Splitting of d orbitals in the octahedral crystal field

Titanium oxide, Ti203, has absorption at 500 nm, but the isolated Ti has no absorption at that wavelength. The absorption corresponds to the titanium electron transfer from the t2g into Og level, so it is easy to calculate the value of Aq for X = 500 nm it amounts to 238 kJmor (57 kcalmol ), or 2.5 eV per one electron. Consequently, the stabilization energy of the octahedral crystal field of 4 Dq is approximately 1 eV per one electron. 

In square planar complexes, the d orbitals exhibit four different relationships. The lobes of the d 2 2 orbital point towards ligands and have the highest orbital energy. The lobes of the d orbital lie between orbitals but are coplanar with them, so this orbital is the next highest in energy. The lobes of 

The 3dj2 and 3d 2 2 orbitals of an octahedral complex, along with the 4s and three 4p orbitals are assumed to overlap six ligand orbitals, forming six bonding molecular orbitals and six antibonding molecular orbitals. 

One should bear in mind that the crystal field theory foresees the electron transition from the t2g orbital into the eg level, but these transitions are symmetry forbidden. The t2g orbitals which do not overlap the o orbitals of the ligands are actually nonbonding, but the t2g orbitals can form bonds through n bonding. 

Crystal-field stabilization energies of d orbitals for various geometric configurations, and substitution rates 

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