Discuss the nature of bonding and magnetic behaviour in the `[Co(C_(2)O_(4))_(3)]^(3-)` Co-ordination entities on the basis of valence bond theory.

Explanation

`[Co(C_(2)O_(4))_(3)]^(3-)` : In this complex, the oxidation state of Co is + 3.
Outer configuration of `Co = 3d^(7) 4s^(2)`

Oxalate ion being a strong field ligand pair .up the 3d electrons, thus two out of the five 3d-orbitals are available for oxalate ions.

Since, all the electrons are paired, this complex is diamagnetic. It is an inner orbital complex because of the involvement of (n - 1) d-orbital for bonding,