Crystal field splitting in octahedral complexes

Crystal Field Splitting in Octahedral Complexes Color Magnetic Properties Tetrahedral and Square-Planar Complexes... 

The value of crystal field splitting in tetrahedral complexes is about half of that in octahedral complexes. 

M Figure 24.32 Crystal-field splitting in a series of octahedral chromiurn(lll) complexes. 

Comparison of crystal field splitting in a square-planar and an octahedral complex... 

Figure 20-12 summarizes the electrical interactions of an octahedral complex ion. The three orbitals that are more stable are called 2 g orbitals, and the two less stable orbitals are called Sg orbitals. The difference in energy between the two sets is known as the crystal field splitting energy, symbolized by the Greek letter h. 

Foyt et al. [137] interpreted the quadrupole-splitting parameters of low-spin ruthenium(II) complexes in terms of a crystal field model in the strong-field approximation with the configuration treated as an equivalent one-electron problem. They have shown that, starting from pure octahedral symmetry with zero quadrupole splitting, A q increases as the ratio of the axial distortion to the spin-orbit coupling increases. 

More recently it has been found15 that a correlation exists between spectroscopic parameters of the divalent aqua ions of the metals Cr to Ni, and the polarographic y2. A linear relationship was found between A0 and crystal field splitting parameter, ot the transfer coefficient, n the number of electrons transferred in the reduction, EVl the polarographic half-wave potential and E° the standard electrode potential. The use of the crystal field splitting parameter would seem to be a more sensible parameter to use than the position of Amax for the main absorption band as the measured Amax may not be a true estimate of the relevant electronic transition. This arises because the symmetry of the complex is less than octahedral so that the main absorption band in octahedral symmetry is split into at least two components with the result that... 

Figure 1-12. Simplified molecular orbital diagram for the formation of an octahedral ML6 complex in which there are no Tt-bonding interactions between metal and ligand. The labels on the molecular orbitals refer to their symmetries. Notice the central region may be equated to the crystal field splitting of the d orbitals.

---