Octahedral Metal Complexes
Crystal field theory predicts that the five d orbitals split.
3 orbitals of low energy, t2g
2 orbitals of high energy, eg
The energy ‘gap’ between the two sets of orbitals depends on the ligands.
I-<Br-<Cl-<F-<OH-<H2O<NH3<NO2-<PPh3<CH3-<CN-<CO (the spectrochemical series)