Explanation for MLCT(Metal to Ligand Charge Transfer) and LMCT (Ligand to Metal Charge Transfer)

1. CHARGE
TRANSFER
COLOR OF COMPLEXES
SHOBANA.N.S
QUEEN MARY’S COLLEGE

2. INTRODUCTION
• Colour provides a vital enhancement to the
world in which we live.
• Every day materials we use - textiles, paints,
plastics, paper, and foodstuffs - are especially
appealing if they are colourful.

3. ABSORPTION OF LIGHT

4. COLOR OF TRANSITION COMPLEXES
• DUE TO:
1. d-d transition
2. charge transfer
3. Spin allowed transition

5. CHARGE TRANSFER

6. WHAT DOES CHARGE -TRANSFER MEAN ??
Usually charge refers the charge of electron,
which is being transferred within the molecular
entity.

7. Four types of charge transfer complexes are
known :
1. LIGAND TO METAL CHARGE TRANSFER
2. METAL TO LIGAND CHARGE TRANSFER
3. METAL TO METAL CHARGE TRANSFER
4. LIGAND TO LIGAND CHARGE TRANSFER

8. LIGAND TO METAL CHARGE
TRANSFER COMPLEXES

9. CONDITION
1. Presence of pi donor ligands:
F-, Cl, Br-, I-, H2O, OH-, RS-, S2
-, NCS-, NCO.
2. Metal ions are devoid of d- electrons.

13. METAL TO LIGAND CHARGE
TRANSFER COMPLEXES

14. CONDITION
1. Presence of pi accepting ligands
CO, NO, CN-, N2, bipy, phen, RNC, C5H5
-, C=C,
C=C
2. Metal in 0,+1,+2 oxidation states ( low oxidation
state).

15. Tris(bipyridine)ruthenium(II)
dichloride
[Ru(bpy)3]Cl2.

18. SPECTRA

19. KMnO4 Spectra LMCT

20. MLCT Tris(bipyridine)ruthenium(II) dichloride

21. THANK YOU !!!