Question

The magnitude of CFSE (Crystal Field Splitting Energy, ${\Delta }_0$) can be related to the configuration of d - orbitals in a coordination entity as?

• A. If ${\Delta }_0$ < P, the configuration is $t_{2g}^3{e}_g^1$ = weak filed ligand and high spin complex.
• B. If ${\Delta }_0$ > P, the configuration is $t_{2g}^3{e}_g^1$ = strong filed ligand and high spin complex.
• C. If ${\Delta }_0$ > P, the configuration is $t_{2g}^4{e}_g^0$ = strong filed ligand and high spin complex.
• D. If ${\Delta }_0=$ P, the configuration is $t_{2g}^4{e}_g^0$ = strong filed ligand and high spin complex.

Answer 1

The correct option is A If ${\Delta }_0$ < P, the configuration is $t_{2g}^3{e}_g^1$ = weak filed ligand and high spin complex.

$I.$ In case of weak field ligand Crystal Field Splitting Energy, ${\Delta }_o<P\Rightarrow$ So, pairing will not take place.
For - $d^4$, the configuration is $t_{2g}^3{e}_g^1$ and high spin complex will form

$II.$ In case of strong field ligand (low spin) Crystal Field Splitting Energy, ${\Delta }_o>P\Rightarrow$ Pairing will take place
For - $d^4$, the configuration is $t_{2g}^4{e}_g^0$ and low spin complex will form