In high spin octahedral d5 complexes like [Mn(H2O)6]2+, Mn2+ ion has five unpaired electrons which are filled parallelly in all the t2g and eg orbitals. 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 reason for the colour of potassium dichromate. Colour of dichromate ion. Why is chromate yellow in colour. Charge transfer transition. LMCT transition.