Crystal field splitting in tetrahedral complexes
In tetrahedral complexes, four ligands may be imagined to occupy the alternate comers of the cube and the metal ion at the center of the cube.
Energy of t2g set of orbitals > Energy of eg set of orbitals.
In such complexes d – orbital splitting is inverted and is smaller as compared to the octahedral field splitting.
Orbital splitting energies are so low that pairing of electrons are not possible so these are high spin complexes.
Colour in Coordination Compounds
The crystal field theory attributes the colour of the coordination compounds to dod transition of the electron, i. e., electron jump from t2g level to higher eg level.
In the absence of ligands, crystal field splitting does not occur and hence the substance is colourless.