Edubuzz Notes

Metal to Ligand Charge Transfer (MLCT) Transition. Metal to Ligand Charge Transfer (MLCT) transition is the transfer of an electron from an orbital with primarily metal character to one with primarily ligand character.

lthough the crystal field theory explains successfully various physical properties of a complex, yet there are certain limitations of the crystal field theory. The limitations of the crystal field theory are as follows.

What are the postulates of crystal field theory.

Why tetrahedral complexes are high spin. Tetrahedral complexes are always high spin whether the ligands are strong or weak?

Why is Δo the double of Δt. Why is crystal field splitting in octahedral complexes is double than that in tetrahedral complexes.

What is the reason for the colour of potassium dichromate. Colour of dichromate ion. Why is chromate yellow in colour. Charge transfer transition. LMCT transition.

How Mn2+(aq) ion gives light pink colour ? Since any d-d transition involves reversal of spins, therefore, d-d transitions are spin forbidden. The d-d transitions are also Laporte forbidden because of the presence of centre of symmetry. Thus, Mn²⁺ (aq) ion gives light pink colour.

Why is [Ti(H2O)6)] 3+ violet in colour. The violet/purple colour of [Ti(H2O)6)] 3+ ion is due to absorption of blue-green light and transition of electron of the t2g orbitals to one of the degenerate eg ortibals. The absorption spectrum of [Ti(H2O)6)] 3+ reveals that the d-d transition occurs with a single broad peak.

What is the difference between d-d transition and charge transfer transition. How do we distinguish between d-d and MLCT transistions.