Give the electronic configuration of d-orbitals of K_(3)[Fe(CN)_(6)] and K_(3)[FeF_(6)] and explain why these complexes give different colours with same solution.

Give the electronic configuration of d-orbitals of K_(3)[Fe(CN)_(6)] a

1.	Give the electronic configuration of d-orbitals of K_(3)[Fe(CN)_(6)] and K_(3)[FeF_(6)] and explain why these complexes give different colours with same solution.
Answer» Solution :`K_(3)[Fe(CN)_(6)]` : Oxidation state of Fe in the compound is +3. Configuration of `Fe^(3+)` and `Ar3d^(5)` In the PRESENCE of `CN^(-)` ions, pairing of electrons TAKES place under : These electrons will REMAIN in t2g orbitals and eg orbitals will remain empty. `K_(3)[FeF_(6)]` : Here also the oxidation number of Fe is +3. The configuration of Fe3+ in the presence of `F^(-)` will be Here due to weak ligand, coupling will not take place. There are 5 unpaired electrons in this case.The COLOUR shown by a coordination compound is due to excitation of electrons within d-d orbitals (from `t_(2g)` to `e_(g)`)- As the distribution of electrons in the two coordination compounds is different, they will show different colours.