The hexaquo manganese (II) ion contains five unpaired electrons, while the hexacyano ion contains only one unpaired electron. Explain using Crystal Field Theory.
[Mn(H2O)6]+2 | [Mn(CN)6]4- |
Oxidation state of manganese: Overall charge balance: X + 6(0) = 2 X = + 2 | Oxidation state of manganese: Overall charge balance: X + 6(-1) = -4 X = + 2 |
Outer electronic configuration of Mn = d5 | Outer electronic configuration of Mn = d5 |
H2O is a weak field ligand so it does not cause pairing of the electron. Therefore Mn undergoes sp3d2 hybridization. Geometry is octahedral. Therefore the 5 unpaired electrons from the d orbital remain as it is. | CN is a strong field ligand so it causes pairing of the electron(5 electrons get paired to form 2 pairs and one unpaired electron). Therefore Mn undergoes d2sp3 hybridization. Geometry is octahedral. |
Mn in + 2 oxidation state:
In presence of CN- Ligands:
d2sp3 hybridisation:
Electronic configuration of [Mn(CN)6]4-:
