Discuss the nature of bonding in the following coordination entities on the basis of Valence bond theory: i) `[Fe(CN)_6]^+` ii) `[FeF_6]^(3-)` iii) `[Co(C_2 O_4)_3]^(3-)` iv) `[CoF_6]^(3-)`

Explanation

i) .Fe(26). has electronic configuration [Ar] .4 ~s^2 3 ~d^5.
.Fe^7+. has electronic configuration .4 s^circ 3 ~d^6.. CN-ion causes pairing of electrons because it is a strong field-ligand.
It has octahedral shape and is diamagnetic in nature due to absence of unpaired elec
trons.
ii) .Fe(26) ,[Ar] 4 ~s^2 3 ~d^6, Fe^3+ ,[Ar] 4 s^circ 3 ~d^3.
.F^-. is weak field ligand, does not cause pairing of electrons.
figure
iii) .operatornameCo(27):[Ar] 4 ~s^3 3 ~d^7, Co^3+:[Ar] 4 ~s^circ 3 ~d_-^6.
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